drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2004 Douglas Gilbert
  11  *
  12  *  Modified  19-JAN-1998  Richard Gooch <rgooch@atnf.csiro.au>  Devfs support
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  */
  20
  21 static int sg_version_num = 30531;      /* 2 digits for each component */
  22 #define SG_VERSION_STR "3.5.31"
  23
  24 /*
  25  *  D. P. Gilbert (dgilbert@interlog.com, dougg@triode.net.au), notes:
  26  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  27  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  28  *        (otherwise the macros compile to empty statements).
  29  *
  30  */
  31 #include <linux/config.h>
  32 #include <linux/module.h>
  33
  34 #include <linux/fs.h>
  35 #include <linux/kernel.h>
  36 #include <linux/sched.h>
  37 #include <linux/string.h>
  38 #include <linux/mm.h>
  39 #include <linux/errno.h>
  40 #include <linux/mtio.h>
  41 #include <linux/ioctl.h>
  42 #include <linux/fcntl.h>
  43 #include <linux/init.h>
  44 #include <linux/poll.h>
  45 #include <linux/smp_lock.h>
  46 #include <linux/moduleparam.h>
  47 #include <linux/devfs_fs_kernel.h>
  48 #include <linux/cdev.h>
  49 #include <linux/seq_file.h>
  50 #include <linux/blkdev.h>
  51 #include <linux/delay.h>
  52
  53 #include "scsi.h"
  54 #include <scsi/scsi_host.h>
  55 #include <scsi/scsi_driver.h>
  56 #include <scsi/scsi_ioctl.h>
  57 #include <scsi/sg.h>
  58
  59 #include "scsi_logging.h"
  60
  61 #ifdef CONFIG_SCSI_PROC_FS
  62 #include <linux/proc_fs.h>
  63 static char *sg_version_date = "20040516";
  64
  65 static int sg_proc_init(void);
  66 static void sg_proc_cleanup(void);
  67 #endif
  68
  69 #ifndef LINUX_VERSION_CODE
  70 #include <linux/version.h>
  71 #endif                          /* LINUX_VERSION_CODE */
  72
  73 #define SG_ALLOW_DIO_DEF 0
  74 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
  75
  76 #define SG_MAX_DEVS 32768
  77
  78 /*
  79  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  80  * Then when using 32 bit integers x * m may overflow during the calculation.
  81  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  82  * calculates the same, but prevents the overflow when both m and d
  83  * are "small" numbers (like HZ and USER_HZ).
  84  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  85  * in 32 bits.
  86  */
  87 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  88
  89 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  90
  91 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  92 /* N.B. This variable is readable and writeable via
  93    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  94    of this size (or less if there is not enough memory) will be reserved
  95    for use by this file descriptor. [Deprecated usage: this variable is also
  96    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  97    the kernel (i.e. it is not a module).] */
  98 static int def_reserved_size = -1;      /* picks up init parameter */
  99 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
 100
 101 #define SG_SECTOR_SZ 512
 102 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 103
 104 #define SG_DEV_ARR_LUMP 32      /* amount to over allocate sg_dev_arr by */
 105
 106 static int sg_add(struct class_device *);
 107 static void sg_remove(struct class_device *);
 108
 109 static Scsi_Request *dummy_cmdp;        /* only used for sizeof */
 110
 111 static rwlock_t sg_dev_arr_lock = RW_LOCK_UNLOCKED;     /* Also used to lock
 112                                                            file descriptor list for device */
 113
 114 static struct class_interface sg_interface = {
 115         .add            = sg_add,
 116         .remove         = sg_remove,
 117 };
 118
 119 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 120         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 121         unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
 122         unsigned bufflen;       /* Size of (aggregate) data buffer */
 123         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
 124         void *buffer;           /* Data buffer or scatter list (k_use_sg>0) */
 125         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 126         unsigned char cmd_opcode; /* first byte of command */
 127 } Sg_scatter_hold;
 128
 129 struct sg_device;               /* forward declarations */
 130 struct sg_fd;
 131
 132 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 133         Scsi_Request *my_cmdp;  /* != 0  when request with lower levels */
 134         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 135         struct sg_fd *parentfp; /* NULL -> not in use */
 136         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 137         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 138         unsigned char sense_b[sizeof (dummy_cmdp->sr_sense_buffer)];
 139         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 140         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 141         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 142         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 143 } Sg_request;
 144
 145 typedef struct sg_fd {          /* holds the state of a file descriptor */
 146         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 147         struct sg_device *parentdp;     /* owning device */
 148         wait_queue_head_t read_wait;    /* queue read until command done */
 149         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 150         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 151         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 152         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 153         unsigned save_scat_len; /* original length of trunc. scat. element */
 154         Sg_request *headrp;     /* head of request slist, NULL->empty */
 155         struct fasync_struct *async_qp; /* used by asynchronous notification */
 156         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 157         char low_dma;           /* as in parent but possibly overridden to 1 */
 158         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 159         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 160         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 161         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 162         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 163         char mmap_called;       /* 0 -> mmap() never called on this fd */
 164 } Sg_fd;
 165
 166 typedef struct sg_device { /* holds the state of each scsi generic device */
 167         struct scsi_device *device;
 168         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 169         int sg_tablesize;       /* adapter's max scatter-gather table size */
 170         Sg_fd *headfp;          /* first open fd belonging to this device */
 171         volatile char detached; /* 0->attached, 1->detached pending removal */
 172         volatile char exclude;  /* opened for exclusive access */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176 } Sg_device;
 177
 178 static int sg_fasync(int fd, struct file *filp, int mode);
 179 static void sg_cmd_done(Scsi_Cmnd * SCpnt);     /* tasklet or soft irq callback */
 180 static int sg_start_req(Sg_request * srp);
 181 static void sg_finish_rem_req(Sg_request * srp);
 182 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 183 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
 184                          int tablesize);
 185 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 186                            Sg_request * srp);
 187 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 188                             int blocking, int read_only, Sg_request ** o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
 192                       int wr_xf, int *countp, unsigned char __user **up);
 193 static int sg_write_xfer(Sg_request * srp);
 194 static int sg_read_xfer(Sg_request * srp);
 195 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 196 static void sg_remove_scat(Sg_scatter_hold * schp);
 197 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 198 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 199 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 200 static char *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
 201 static void sg_page_free(char *buff, int size);
 202 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 203 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 204 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 205 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 206 static Sg_request *sg_add_request(Sg_fd * sfp);
 207 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 208 static int sg_res_in_use(Sg_fd * sfp);
 209 static int sg_allow_access(unsigned char opcode, char dev_type);
 210 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
 211 static Sg_device *sg_get_dev(int dev);
 212 static inline unsigned char *sg_scatg2virt(const struct scatterlist *sclp);
 213 #ifdef CONFIG_SCSI_PROC_FS
 214 static int sg_last_dev(void);
 215 #endif
 216
 217 static Sg_device **sg_dev_arr = NULL;
 218 static int sg_dev_max;
 219 static int sg_nr_dev;
 220
 221 #define SZ_SG_HEADER sizeof(struct sg_header)
 222 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 223 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 224 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 225
 226 static int
 227 sg_open(struct inode *inode, struct file *filp)
 228 {
 229         int dev = iminor(inode);
 230         int flags = filp->f_flags;
 231         Sg_device *sdp;
 232         Sg_fd *sfp;
 233         int res;
 234         int retval;
 235
 236         nonseekable_open(inode, filp);
 237         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 238         sdp = sg_get_dev(dev);
 239         if ((!sdp) || (!sdp->device))
 240                 return -ENXIO;
 241         if (sdp->detached)
 242                 return -ENODEV;
 243
 244         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 245         /* Prevent the device driver from vanishing while we sleep */
 246         retval = scsi_device_get(sdp->device);
 247         if (retval)
 248                 return retval;
 249
 250         if (!((flags & O_NONBLOCK) ||
 251               scsi_block_when_processing_errors(sdp->device))) {
 252                 retval = -ENXIO;
 253                 /* we are in error recovery for this device */
 254                 goto error_out;
 255         }
 256
 257         if (flags & O_EXCL) {
 258                 if (O_RDONLY == (flags & O_ACCMODE)) {
 259                         retval = -EPERM; /* Can't lock it with read only access */
 260                         goto error_out;
 261                 }
 262                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 263                         retval = -EBUSY;
 264                         goto error_out;
 265                 }
 266                 res = 0;
 267                 __wait_event_interruptible(sdp->o_excl_wait,
 268                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 269                 if (res) {
 270                         retval = res;   /* -ERESTARTSYS because signal hit process */
 271                         goto error_out;
 272                 }
 273         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 274                 if (flags & O_NONBLOCK) {
 275                         retval = -EBUSY;
 276                         goto error_out;
 277                 }
 278                 res = 0;
 279                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 280                                            res);
 281                 if (res) {
 282                         retval = res;   /* -ERESTARTSYS because signal hit process */
 283                         goto error_out;
 284                 }
 285         }
 286         if (sdp->detached) {
 287                 retval = -ENODEV;
 288                 goto error_out;
 289         }
 290         if (!sdp->headfp) {     /* no existing opens on this device */
 291                 sdp->sgdebug = 0;
 292                 sdp->sg_tablesize = sdp->device->host->sg_tablesize;
 293         }
 294         if ((sfp = sg_add_sfp(sdp, dev)))
 295                 filp->private_data = sfp;
 296         else {
 297                 if (flags & O_EXCL)
 298                         sdp->exclude = 0;       /* undo if error */
 299                 retval = -ENOMEM;
 300                 goto error_out;
 301         }
 302         return 0;
 303
 304       error_out:
 305         scsi_device_put(sdp->device);
 306         return retval;
 307 }
 308
 309 /* Following function was formerly called 'sg_close' */
 310 static int
 311 sg_release(struct inode *inode, struct file *filp)
 312 {
 313         Sg_device *sdp;
 314         Sg_fd *sfp;
 315
 316         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 317                 return -ENXIO;
 318         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 319         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 320         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 321                 if (!sdp->detached) {
 322                         scsi_device_put(sdp->device);
 323                 }
 324                 sdp->exclude = 0;
 325                 wake_up_interruptible(&sdp->o_excl_wait);
 326         }
 327         return 0;
 328 }
 329
 330 static ssize_t
 331 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 332 {
 333         int k, res;
 334         Sg_device *sdp;
 335         Sg_fd *sfp;
 336         Sg_request *srp;
 337         int req_pack_id = -1;
 338         struct sg_header old_hdr;
 339         sg_io_hdr_t new_hdr;
 340         sg_io_hdr_t *hp;
 341
 342         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 343                 return -ENXIO;
 344         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 345                                    sdp->disk->disk_name, (int) count));
 346         if ((k = verify_area(VERIFY_WRITE, buf, count)))
 347                 return k;
 348         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 349                 if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 350                         return -EFAULT;
 351                 if (old_hdr.reply_len < 0) {
 352                         if (count >= SZ_SG_IO_HDR) {
 353                                 if (__copy_from_user
 354                                     (&new_hdr, buf, SZ_SG_IO_HDR))
 355                                         return -EFAULT;
 356                                 req_pack_id = new_hdr.pack_id;
 357                         }
 358                 } else
 359                         req_pack_id = old_hdr.pack_id;
 360         }
 361         srp = sg_get_rq_mark(sfp, req_pack_id);
 362         if (!srp) {             /* now wait on packet to arrive */
 363                 if (sdp->detached)
 364                         return -ENODEV;
 365                 if (filp->f_flags & O_NONBLOCK)
 366                         return -EAGAIN;
 367                 while (1) {
 368                         res = 0;        /* following is a macro that beats race condition */
 369                         __wait_event_interruptible(sfp->read_wait,
 370                                 (sdp->detached || (srp = sg_get_rq_mark(sfp, req_pack_id))),
 371                                                    res);
 372                         if (sdp->detached)
 373                                 return -ENODEV;
 374                         if (0 == res)
 375                                 break;
 376                         return res;     /* -ERESTARTSYS because signal hit process */
 377                 }
 378         }
 379         if (srp->header.interface_id != '\0')
 380                 return sg_new_read(sfp, buf, count, srp);
 381
 382         hp = &srp->header;
 383         memset(&old_hdr, 0, SZ_SG_HEADER);
 384         old_hdr.reply_len = (int) hp->timeout;
 385         old_hdr.pack_len = old_hdr.reply_len; /* very old, strange behaviour */
 386         old_hdr.pack_id = hp->pack_id;
 387         old_hdr.twelve_byte =
 388             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 389         old_hdr.target_status = hp->masked_status;
 390         old_hdr.host_status = hp->host_status;
 391         old_hdr.driver_status = hp->driver_status;
 392         if ((CHECK_CONDITION & hp->masked_status) ||
 393             (DRIVER_SENSE & hp->driver_status))
 394                 memcpy(old_hdr.sense_buffer, srp->sense_b,
 395                        sizeof (old_hdr.sense_buffer));
 396         switch (hp->host_status) {
 397         /* This setup of 'result' is for backward compatibility and is best
 398            ignored by the user who should use target, host + driver status */
 399         case DID_OK:
 400         case DID_PASSTHROUGH:
 401         case DID_SOFT_ERROR:
 402                 old_hdr.result = 0;
 403                 break;
 404         case DID_NO_CONNECT:
 405         case DID_BUS_BUSY:
 406         case DID_TIME_OUT:
 407                 old_hdr.result = EBUSY;
 408                 break;
 409         case DID_BAD_TARGET:
 410         case DID_ABORT:
 411         case DID_PARITY:
 412         case DID_RESET:
 413         case DID_BAD_INTR:
 414                 old_hdr.result = EIO;
 415                 break;
 416         case DID_ERROR:
 417                 old_hdr.result = (srp->sense_b[0] == 0 &&
 418                                   hp->masked_status == GOOD) ? 0 : EIO;
 419                 break;
 420         default:
 421                 old_hdr.result = EIO;
 422                 break;
 423         }
 424
 425         /* Now copy the result back to the user buffer.  */
 426         if (count >= SZ_SG_HEADER) {
 427                 if (__copy_to_user(buf, &old_hdr, SZ_SG_HEADER))
 428                         return -EFAULT;
 429                 buf += SZ_SG_HEADER;
 430                 if (count > old_hdr.reply_len)
 431                         count = old_hdr.reply_len;
 432                 if (count > SZ_SG_HEADER) {
 433                         if ((res =
 434                              sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)))
 435                                 return -EFAULT;
 436                 }
 437         } else
 438                 count = (old_hdr.result == 0) ? 0 : -EIO;
 439         sg_finish_rem_req(srp);
 440         return count;
 441 }
 442
 443 static ssize_t
 444 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 445 {
 446         sg_io_hdr_t *hp = &srp->header;
 447         int err = 0;
 448         int len;
 449
 450         if (count < SZ_SG_IO_HDR) {
 451                 err = -EINVAL;
 452                 goto err_out;
 453         }
 454         hp->sb_len_wr = 0;
 455         if ((hp->mx_sb_len > 0) && hp->sbp) {
 456                 if ((CHECK_CONDITION & hp->masked_status) ||
 457                     (DRIVER_SENSE & hp->driver_status)) {
 458                         int sb_len = sizeof (dummy_cmdp->sr_sense_buffer);
 459                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 460                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 461                         len = (len > sb_len) ? sb_len : len;
 462                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 463                                 err = -EFAULT;
 464                                 goto err_out;
 465                         }
 466                         hp->sb_len_wr = len;
 467                 }
 468         }
 469         if (hp->masked_status || hp->host_status || hp->driver_status)
 470                 hp->info |= SG_INFO_CHECK;
 471         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 472                 err = -EFAULT;
 473                 goto err_out;
 474         }
 475         err = sg_read_xfer(srp);
 476       err_out:
 477         sg_finish_rem_req(srp);
 478         return (0 == err) ? count : err;
 479 }
 480
 481 static ssize_t
 482 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 483 {
 484         int mxsize, cmd_size, k;
 485         int input_size, blocking;
 486         unsigned char opcode;
 487         Sg_device *sdp;
 488         Sg_fd *sfp;
 489         Sg_request *srp;
 490         struct sg_header old_hdr;
 491         sg_io_hdr_t *hp;
 492         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
 493
 494         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 495                 return -ENXIO;
 496         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 497                                    sdp->disk->disk_name, (int) count));
 498         if (sdp->detached)
 499                 return -ENODEV;
 500         if (!((filp->f_flags & O_NONBLOCK) ||
 501               scsi_block_when_processing_errors(sdp->device)))
 502                 return -ENXIO;
 503
 504         if ((k = verify_area(VERIFY_READ, buf, count)))
 505                 return k;       /* protects following copy_from_user()s + get_user()s */
 506         if (count < SZ_SG_HEADER)
 507                 return -EIO;
 508         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 509                 return -EFAULT;
 510         blocking = !(filp->f_flags & O_NONBLOCK);
 511         if (old_hdr.reply_len < 0)
 512                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
 513         if (count < (SZ_SG_HEADER + 6))
 514                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 515
 516         if (!(srp = sg_add_request(sfp))) {
 517                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 518                 return -EDOM;
 519         }
 520         buf += SZ_SG_HEADER;
 521         __get_user(opcode, buf);
 522         if (sfp->next_cmd_len > 0) {
 523                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 524                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 525                         sfp->next_cmd_len = 0;
 526                         sg_remove_request(sfp, srp);
 527                         return -EIO;
 528                 }
 529                 cmd_size = sfp->next_cmd_len;
 530                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 531         } else {
 532                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 533                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 534                         cmd_size = 12;
 535         }
 536         SCSI_LOG_TIMEOUT(4, printk(
 537                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 538 /* Determine buffer size.  */
 539         input_size = count - cmd_size;
 540         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 541         mxsize -= SZ_SG_HEADER;
 542         input_size -= SZ_SG_HEADER;
 543         if (input_size < 0) {
 544                 sg_remove_request(sfp, srp);
 545                 return -EIO;    /* User did not pass enough bytes for this command. */
 546         }
 547         hp = &srp->header;
 548         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 549         hp->cmd_len = (unsigned char) cmd_size;
 550         hp->iovec_count = 0;
 551         hp->mx_sb_len = 0;
 552         if (input_size > 0)
 553                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 554                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 555         else
 556                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 557         hp->dxfer_len = mxsize;
 558         hp->dxferp = (char __user *)buf + cmd_size;
 559         hp->sbp = NULL;
 560         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 561         hp->flags = input_size; /* structure abuse ... */
 562         hp->pack_id = old_hdr.pack_id;
 563         hp->usr_ptr = NULL;
 564         if (__copy_from_user(cmnd, buf, cmd_size))
 565                 return -EFAULT;
 566         /*
 567          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 568          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 569          * is a non-zero input_size, so emit a warning.
 570          */
 571         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
 572                 if (printk_ratelimit())
 573                         printk(KERN_WARNING
 574                                "sg_write: data in/out %d/%d bytes for SCSI command 0x%x--"
 575                                "guessing data in;\n" KERN_WARNING "   "
 576                                "program %s not setting count and/or reply_len properly\n",
 577                                old_hdr.reply_len - (int)SZ_SG_HEADER,
 578                                input_size, (unsigned int) cmnd[0],
 579                                current->comm);
 580         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 581         return (k < 0) ? k : count;
 582 }
 583
 584 static ssize_t
 585 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 586              int blocking, int read_only, Sg_request ** o_srp)
 587 {
 588         int k;
 589         Sg_request *srp;
 590         sg_io_hdr_t *hp;
 591         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
 592         int timeout;
 593         unsigned long ul_timeout;
 594
 595         if (count < SZ_SG_IO_HDR)
 596                 return -EINVAL;
 597         if ((k = verify_area(VERIFY_READ, buf, count)))
 598                 return k; /* protects following copy_from_user()s + get_user()s */
 599
 600         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 601         if (!(srp = sg_add_request(sfp))) {
 602                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 603                 return -EDOM;
 604         }
 605         hp = &srp->header;
 606         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 607                 sg_remove_request(sfp, srp);
 608                 return -EFAULT;
 609         }
 610         if (hp->interface_id != 'S') {
 611                 sg_remove_request(sfp, srp);
 612                 return -ENOSYS;
 613         }
 614         if (hp->flags & SG_FLAG_MMAP_IO) {
 615                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 616                         sg_remove_request(sfp, srp);
 617                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 618                 }
 619                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 620                         sg_remove_request(sfp, srp);
 621                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 622                 }
 623                 if (sg_res_in_use(sfp)) {
 624                         sg_remove_request(sfp, srp);
 625                         return -EBUSY;  /* reserve buffer already being used */
 626                 }
 627         }
 628         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 629         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 630         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 631                 sg_remove_request(sfp, srp);
 632                 return -EMSGSIZE;
 633         }
 634         if ((k = verify_area(VERIFY_READ, hp->cmdp, hp->cmd_len))) {
 635                 sg_remove_request(sfp, srp);
 636                 return k;       /* protects following copy_from_user()s + get_user()s */
 637         }
 638         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 639                 sg_remove_request(sfp, srp);
 640                 return -EFAULT;
 641         }
 642         if (read_only &&
 643             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
 644                 sg_remove_request(sfp, srp);
 645                 return -EPERM;
 646         }
 647         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 648         if (k < 0)
 649                 return k;
 650         if (o_srp)
 651                 *o_srp = srp;
 652         return count;
 653 }
 654
 655 static int
 656 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 657                 unsigned char *cmnd, int timeout, int blocking)
 658 {
 659         int k;
 660         Scsi_Request *SRpnt;
 661         Sg_device *sdp = sfp->parentdp;
 662         sg_io_hdr_t *hp = &srp->header;
 663         request_queue_t *q;
 664
 665         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 666         hp->status = 0;
 667         hp->masked_status = 0;
 668         hp->msg_status = 0;
 669         hp->info = 0;
 670         hp->host_status = 0;
 671         hp->driver_status = 0;
 672         hp->resid = 0;
 673         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 674                           (int) cmnd[0], (int) hp->cmd_len));
 675
 676         if ((k = sg_start_req(srp))) {
 677                 SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
 678                 sg_finish_rem_req(srp);
 679                 return k;       /* probably out of space --> ENOMEM */
 680         }
 681         if ((k = sg_write_xfer(srp))) {
 682                 SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
 683                 sg_finish_rem_req(srp);
 684                 return k;
 685         }
 686         if (sdp->detached) {
 687                 sg_finish_rem_req(srp);
 688                 return -ENODEV;
 689         }
 690         SRpnt = scsi_allocate_request(sdp->device, GFP_ATOMIC);
 691         if (SRpnt == NULL) {
 692                 SCSI_LOG_TIMEOUT(1, printk("sg_write: no mem\n"));
 693                 sg_finish_rem_req(srp);
 694                 return -ENOMEM;
 695         }
 696
 697         srp->my_cmdp = SRpnt;
 698         q = SRpnt->sr_device->request_queue;
 699         SRpnt->sr_request->rq_disk = sdp->disk;
 700         SRpnt->sr_sense_buffer[0] = 0;
 701         SRpnt->sr_cmd_len = hp->cmd_len;
 702         SRpnt->sr_use_sg = srp->data.k_use_sg;
 703         SRpnt->sr_sglist_len = srp->data.sglist_len;
 704         SRpnt->sr_bufflen = srp->data.bufflen;
 705         SRpnt->sr_underflow = 0;
 706         SRpnt->sr_buffer = srp->data.buffer;
 707         switch (hp->dxfer_direction) {
 708         case SG_DXFER_TO_FROM_DEV:
 709         case SG_DXFER_FROM_DEV:
 710                 SRpnt->sr_data_direction = SCSI_DATA_READ;
 711                 break;
 712         case SG_DXFER_TO_DEV:
 713                 SRpnt->sr_data_direction = SCSI_DATA_WRITE;
 714                 break;
 715         case SG_DXFER_UNKNOWN:
 716                 SRpnt->sr_data_direction = SCSI_DATA_UNKNOWN;
 717                 break;
 718         default:
 719                 SRpnt->sr_data_direction = SCSI_DATA_NONE;
 720                 break;
 721         }
 722         SRpnt->upper_private_data = srp;
 723         srp->data.k_use_sg = 0;
 724         srp->data.sglist_len = 0;
 725         srp->data.bufflen = 0;
 726         srp->data.buffer = NULL;
 727         hp->duration = jiffies; /* unit jiffies now, millisecs after done */
 728 /* Now send everything of to mid-level. The next time we hear about this
 729    packet is when sg_cmd_done() is called (i.e. a callback). */
 730         scsi_do_req(SRpnt, (void *) cmnd,
 731                     (void *) SRpnt->sr_buffer, hp->dxfer_len,
 732                     sg_cmd_done, timeout, SG_DEFAULT_RETRIES);
 733         /* dxfer_len overwrites SRpnt->sr_bufflen, hence need for b_malloc_len */
 734         return 0;
 735 }
 736
 737 static int
 738 sg_srp_done(Sg_request *srp, Sg_fd *sfp)
 739 {
 740         unsigned long iflags;
 741         int done;
 742
 743         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 744         done = srp->done;
 745         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 746         return done;
 747 }
 748
 749 static int
 750 sg_ioctl(struct inode *inode, struct file *filp,
 751          unsigned int cmd_in, unsigned long arg)
 752 {
 753         void __user *p = (void __user *)arg;
 754         int __user *ip = p;
 755         int result, val, read_only;
 756         Sg_device *sdp;
 757         Sg_fd *sfp;
 758         Sg_request *srp;
 759         unsigned long iflags;
 760
 761         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 762                 return -ENXIO;
 763         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 764                                    sdp->disk->disk_name, (int) cmd_in));
 765         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 766
 767         switch (cmd_in) {
 768         case SG_IO:
 769                 {
 770                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 771
 772                         if (sdp->detached)
 773                                 return -ENODEV;
 774                         if (!scsi_block_when_processing_errors(sdp->device))
 775                                 return -ENXIO;
 776                         result = verify_area(VERIFY_WRITE, p, SZ_SG_IO_HDR);
 777                         if (result)
 778                                 return result;
 779                         result =
 780                             sg_new_write(sfp, p, SZ_SG_IO_HDR,
 781                                          blocking, read_only, &srp);
 782                         if (result < 0)
 783                                 return result;
 784                         srp->sg_io_owned = 1;
 785                         while (1) {
 786                                 result = 0;     /* following macro to beat race condition */
 787                                 __wait_event_interruptible(sfp->read_wait,
 788                                         (sdp->detached || sfp->closed || sg_srp_done(srp, sfp)),
 789                                                            result);
 790                                 if (sdp->detached)
 791                                         return -ENODEV;
 792                                 if (sfp->closed)
 793                                         return 0;       /* request packet dropped already */
 794                                 if (0 == result)
 795                                         break;
 796                                 srp->orphan = 1;
 797                                 return result;  /* -ERESTARTSYS because signal hit process */
 798                         }
 799                         write_lock_irqsave(&sfp->rq_list_lock, iflags);
 800                         srp->done = 2;
 801                         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 802                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 803                         return (result < 0) ? result : 0;
 804                 }
 805         case SG_SET_TIMEOUT:
 806                 result = get_user(val, ip);
 807                 if (result)
 808                         return result;
 809                 if (val < 0)
 810                         return -EIO;
 811                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 812                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 813                 sfp->timeout_user = val;
 814                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 815
 816                 return 0;
 817         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 818                                 /* strange ..., for backward compatibility */
 819                 return sfp->timeout_user;
 820         case SG_SET_FORCE_LOW_DMA:
 821                 result = get_user(val, ip);
 822                 if (result)
 823                         return result;
 824                 if (val) {
 825                         sfp->low_dma = 1;
 826                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 827                                 val = (int) sfp->reserve.bufflen;
 828                                 sg_remove_scat(&sfp->reserve);
 829                                 sg_build_reserve(sfp, val);
 830                         }
 831                 } else {
 832                         if (sdp->detached)
 833                                 return -ENODEV;
 834                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 835                 }
 836                 return 0;
 837         case SG_GET_LOW_DMA:
 838                 return put_user((int) sfp->low_dma, ip);
 839         case SG_GET_SCSI_ID:
 840                 result =
 841                     verify_area(VERIFY_WRITE, p, sizeof (sg_scsi_id_t));
 842                 if (result)
 843                         return result;
 844                 else {
 845                         sg_scsi_id_t __user *sg_idp = p;
 846
 847                         if (sdp->detached)
 848                                 return -ENODEV;
 849                         __put_user((int) sdp->device->host->host_no,
 850                                    &sg_idp->host_no);
 851                         __put_user((int) sdp->device->channel,
 852                                    &sg_idp->channel);
 853                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 854                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 855                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 856                         __put_user((short) sdp->device->host->cmd_per_lun,
 857                                    &sg_idp->h_cmd_per_lun);
 858                         __put_user((short) sdp->device->queue_depth,
 859                                    &sg_idp->d_queue_depth);
 860                         __put_user(0, &sg_idp->unused[0]);
 861                         __put_user(0, &sg_idp->unused[1]);
 862                         return 0;
 863                 }
 864         case SG_SET_FORCE_PACK_ID:
 865                 result = get_user(val, ip);
 866                 if (result)
 867                         return result;
 868                 sfp->force_packid = val ? 1 : 0;
 869                 return 0;
 870         case SG_GET_PACK_ID:
 871                 result = verify_area(VERIFY_WRITE, ip, sizeof (int));
 872                 if (result)
 873                         return result;
 874                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 875                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 876                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 877                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 878                                                        iflags);
 879                                 __put_user(srp->header.pack_id, ip);
 880                                 return 0;
 881                         }
 882                 }
 883                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 884                 __put_user(-1, ip);
 885                 return 0;
 886         case SG_GET_NUM_WAITING:
 887                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 888                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 889                         if ((1 == srp->done) && (!srp->sg_io_owned))
 890                                 ++val;
 891                 }
 892                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 893                 return put_user(val, ip);
 894         case SG_GET_SG_TABLESIZE:
 895                 return put_user(sdp->sg_tablesize, ip);
 896         case SG_SET_RESERVED_SIZE:
 897                 result = get_user(val, ip);
 898                 if (result)
 899                         return result;
 900                 if (val < 0)
 901                         return -EINVAL;
 902                 if (val != sfp->reserve.bufflen) {
 903                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 904                                 return -EBUSY;
 905                         sg_remove_scat(&sfp->reserve);
 906                         sg_build_reserve(sfp, val);
 907                 }
 908                 return 0;
 909         case SG_GET_RESERVED_SIZE:
 910                 val = (int) sfp->reserve.bufflen;
 911                 return put_user(val, ip);
 912         case SG_SET_COMMAND_Q:
 913                 result = get_user(val, ip);
 914                 if (result)
 915                         return result;
 916                 sfp->cmd_q = val ? 1 : 0;
 917                 return 0;
 918         case SG_GET_COMMAND_Q:
 919                 return put_user((int) sfp->cmd_q, ip);
 920         case SG_SET_KEEP_ORPHAN:
 921                 result = get_user(val, ip);
 922                 if (result)
 923                         return result;
 924                 sfp->keep_orphan = val;
 925                 return 0;
 926         case SG_GET_KEEP_ORPHAN:
 927                 return put_user((int) sfp->keep_orphan, ip);
 928         case SG_NEXT_CMD_LEN:
 929                 result = get_user(val, ip);
 930                 if (result)
 931                         return result;
 932                 sfp->next_cmd_len = (val > 0) ? val : 0;
 933                 return 0;
 934         case SG_GET_VERSION_NUM:
 935                 return put_user(sg_version_num, ip);
 936         case SG_GET_ACCESS_COUNT:
 937                 /* faked - we don't have a real access count anymore */
 938                 val = (sdp->device ? 1 : 0);
 939                 return put_user(val, ip);
 940         case SG_GET_REQUEST_TABLE:
 941                 result = verify_area(VERIFY_WRITE, p,
 942                                      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
 943                 if (result)
 944                         return result;
 945                 else {
 946                         sg_req_info_t rinfo[SG_MAX_QUEUE];
 947                         Sg_request *srp;
 948                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 949                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 950                              ++val, srp = srp ? srp->nextrp : srp) {
 951                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 952                                 if (srp) {
 953                                         rinfo[val].req_state = srp->done + 1;
 954                                         rinfo[val].problem =
 955                                             srp->header.masked_status &
 956                                             srp->header.host_status &
 957                                             srp->header.driver_status;
 958                                         rinfo[val].duration =
 959                                             srp->done ? srp->header.duration :
 960                                             jiffies_to_msecs(
 961                                                 jiffies - srp->header.duration);
 962                                         rinfo[val].orphan = srp->orphan;
 963                                         rinfo[val].sg_io_owned = srp->sg_io_owned;
 964                                         rinfo[val].pack_id = srp->header.pack_id;
 965                                         rinfo[val].usr_ptr = srp->header.usr_ptr;
 966                                 }
 967                         }
 968                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 969                         return (__copy_to_user(p, rinfo,
 970                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE) ? -EFAULT : 0);
 971                 }
 972         case SG_EMULATED_HOST:
 973                 if (sdp->detached)
 974                         return -ENODEV;
 975                 return put_user(sdp->device->host->hostt->emulated, ip);
 976         case SG_SCSI_RESET:
 977                 if (sdp->detached)
 978                         return -ENODEV;
 979                 if (filp->f_flags & O_NONBLOCK) {
 980                         if (test_bit(SHOST_RECOVERY,
 981                                      &sdp->device->host->shost_state))
 982                                 return -EBUSY;
 983                 } else if (!scsi_block_when_processing_errors(sdp->device))
 984                         return -EBUSY;
 985                 result = get_user(val, ip);
 986                 if (result)
 987                         return result;
 988                 if (SG_SCSI_RESET_NOTHING == val)
 989                         return 0;
 990                 switch (val) {
 991                 case SG_SCSI_RESET_DEVICE:
 992                         val = SCSI_TRY_RESET_DEVICE;
 993                         break;
 994                 case SG_SCSI_RESET_BUS:
 995                         val = SCSI_TRY_RESET_BUS;
 996                         break;
 997                 case SG_SCSI_RESET_HOST:
 998                         val = SCSI_TRY_RESET_HOST;
 999                         break;
1000                 default:
1001                         return -EINVAL;
1002                 }
1003                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1004                         return -EACCES;
1005                 return (scsi_reset_provider(sdp->device, val) ==
1006                         SUCCESS) ? 0 : -EIO;
1007         case SCSI_IOCTL_SEND_COMMAND:
1008                 if (sdp->detached)
1009                         return -ENODEV;
1010                 if (read_only) {
1011                         unsigned char opcode = WRITE_6;
1012                         Scsi_Ioctl_Command __user *siocp = p;
1013
1014                         if (copy_from_user(&opcode, siocp->data, 1))
1015                                 return -EFAULT;
1016                         if (!sg_allow_access(opcode, sdp->device->type))
1017                                 return -EPERM;
1018                 }
1019                 return scsi_ioctl_send_command(sdp->device, p);
1020         case SG_SET_DEBUG:
1021                 result = get_user(val, ip);
1022                 if (result)
1023                         return result;
1024                 sdp->sgdebug = (char) val;
1025                 return 0;
1026         case SCSI_IOCTL_GET_IDLUN:
1027         case SCSI_IOCTL_GET_BUS_NUMBER:
1028         case SCSI_IOCTL_PROBE_HOST:
1029         case SG_GET_TRANSFORM:
1030                 if (sdp->detached)
1031                         return -ENODEV;
1032                 return scsi_ioctl(sdp->device, cmd_in, p);
1033         default:
1034                 if (read_only)
1035                         return -EPERM;  /* don't know so take safe approach */
1036                 return scsi_ioctl(sdp->device, cmd_in, p);
1037         }
1038 }
1039
1040 static unsigned int
1041 sg_poll(struct file *filp, poll_table * wait)
1042 {
1043         unsigned int res = 0;
1044         Sg_device *sdp;
1045         Sg_fd *sfp;
1046         Sg_request *srp;
1047         int count = 0;
1048         unsigned long iflags;
1049
1050         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1051             || sfp->closed)
1052                 return POLLERR;
1053         poll_wait(filp, &sfp->read_wait, wait);
1054         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1055         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1056                 /* if any read waiting, flag it */
1057                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1058                         res = POLLIN | POLLRDNORM;
1059                 ++count;
1060         }
1061         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1062
1063         if (sdp->detached)
1064                 res |= POLLHUP;
1065         else if (!sfp->cmd_q) {
1066                 if (0 == count)
1067                         res |= POLLOUT | POLLWRNORM;
1068         } else if (count < SG_MAX_QUEUE)
1069                 res |= POLLOUT | POLLWRNORM;
1070         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1071                                    sdp->disk->disk_name, (int) res));
1072         return res;
1073 }
1074
1075 static int
1076 sg_fasync(int fd, struct file *filp, int mode)
1077 {
1078         int retval;
1079         Sg_device *sdp;
1080         Sg_fd *sfp;
1081
1082         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1083                 return -ENXIO;
1084         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1085                                    sdp->disk->disk_name, mode));
1086
1087         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1088         return (retval < 0) ? retval : 0;
1089 }
1090
1091 static inline unsigned char *
1092 sg_scatg2virt(const struct scatterlist *sclp)
1093 {
1094         return (sclp && sclp->page) ?
1095             (unsigned char *) page_address(sclp->page) + sclp->offset : NULL;
1096 }
1097
1098 /* When startFinish==1 increments page counts for pages other than the
1099    first of scatter gather elements obtained from __get_free_pages().
1100    When startFinish==0 decrements ... */
1101 static void
1102 sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
1103 {
1104         void *page_ptr;
1105         struct page *page;
1106         int k, m;
1107
1108         SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n",
1109                                    startFinish, rsv_schp->k_use_sg));
1110         /* N.B. correction _not_ applied to base page of each allocation */
1111         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1112                 struct scatterlist *sclp = rsv_schp->buffer;
1113
1114                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
1115                         for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
1116                                 page_ptr = sg_scatg2virt(sclp) + m;
1117                                 page = virt_to_page(page_ptr);
1118                                 if (startFinish)
1119                                         get_page(page);
1120                                 else {
1121                                         if (page_count(page) > 0)
1122                                                 __put_page(page);
1123                                 }
1124                         }
1125                 }
1126         } else {                /* reserve buffer is just a single allocation */
1127                 for (m = PAGE_SIZE; m < rsv_schp->bufflen; m += PAGE_SIZE) {
1128                         page_ptr = (unsigned char *) rsv_schp->buffer + m;
1129                         page = virt_to_page(page_ptr);
1130                         if (startFinish)
1131                                 get_page(page);
1132                         else {
1133                                 if (page_count(page) > 0)
1134                                         __put_page(page);
1135                         }
1136                 }
1137         }
1138 }
1139
1140 static struct page *
1141 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1142 {
1143         Sg_fd *sfp;
1144         struct page *page = NOPAGE_SIGBUS;
1145         void *page_ptr = NULL;
1146         unsigned long offset;
1147         Sg_scatter_hold *rsv_schp;
1148
1149         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1150                 return page;
1151         rsv_schp = &sfp->reserve;
1152         offset = addr - vma->vm_start;
1153         if (offset >= rsv_schp->bufflen)
1154                 return page;
1155         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1156                                    offset, rsv_schp->k_use_sg));
1157         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1158                 int k;
1159                 unsigned long sa = vma->vm_start;
1160                 unsigned long len;
1161                 struct scatterlist *sclp = rsv_schp->buffer;
1162
1163                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1164                      ++k, ++sclp) {
1165                         len = vma->vm_end - sa;
1166                         len = (len < sclp->length) ? len : sclp->length;
1167                         if (offset < len) {
1168                                 page_ptr = sg_scatg2virt(sclp) + offset;
1169                                 page = virt_to_page(page_ptr);
1170                                 get_page(page); /* increment page count */
1171                                 break;
1172                         }
1173                         sa += len;
1174                         offset -= len;
1175                 }
1176         } else {                /* reserve buffer is just a single allocation */
1177                 page_ptr = (unsigned char *) rsv_schp->buffer + offset;
1178                 page = virt_to_page(page_ptr);
1179                 get_page(page); /* increment page count */
1180         }
1181         if (type)
1182                 *type = VM_FAULT_MINOR;
1183         return page;
1184 }
1185
1186 static struct vm_operations_struct sg_mmap_vm_ops = {
1187         .nopage = sg_vma_nopage,
1188 };
1189
1190 static int
1191 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1192 {
1193         Sg_fd *sfp;
1194         unsigned long req_sz = vma->vm_end - vma->vm_start;
1195         Sg_scatter_hold *rsv_schp;
1196
1197         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1198                 return -ENXIO;
1199         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1200                                    (void *) vma->vm_start, (int) req_sz));
1201         if (vma->vm_pgoff)
1202                 return -EINVAL; /* want no offset */
1203         rsv_schp = &sfp->reserve;
1204         if (req_sz > rsv_schp->bufflen)
1205                 return -ENOMEM; /* cannot map more than reserved buffer */
1206
1207         if (rsv_schp->k_use_sg) { /* reserve buffer is a scatter gather list */
1208                 int k;
1209                 unsigned long sa = vma->vm_start;
1210                 unsigned long len;
1211                 struct scatterlist *sclp = rsv_schp->buffer;
1212
1213                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1214                      ++k, ++sclp) {
1215                         if (0 != sclp->offset)
1216                                 return -EFAULT; /* non page aligned memory ?? */
1217                         len = vma->vm_end - sa;
1218                         len = (len < sclp->length) ? len : sclp->length;
1219                         sa += len;
1220                 }
1221         } else {        /* reserve buffer is just a single allocation */
1222                 if ((unsigned long) rsv_schp->buffer & (PAGE_SIZE - 1))
1223                         return -EFAULT; /* non page aligned memory ?? */
1224         }
1225         if (0 == sfp->mmap_called) {
1226                 sg_rb_correct4mmap(rsv_schp, 1);        /* do only once per fd lifetime */
1227                 sfp->mmap_called = 1;
1228         }
1229         vma->vm_flags |= (VM_RESERVED | VM_IO);
1230         vma->vm_private_data = sfp;
1231         vma->vm_ops = &sg_mmap_vm_ops;
1232         return 0;
1233 }
1234
1235 /* This function is a "bottom half" handler that is called by the
1236  * mid level when a command is completed (or has failed). */
1237 static void
1238 sg_cmd_done(Scsi_Cmnd * SCpnt)
1239 {
1240         Scsi_Request *SRpnt = NULL;
1241         Sg_device *sdp = NULL;
1242         Sg_fd *sfp;
1243         Sg_request *srp = NULL;
1244         unsigned long iflags;
1245
1246         if (SCpnt && (SRpnt = SCpnt->sc_request))
1247                 srp = (Sg_request *) SRpnt->upper_private_data;
1248         if (NULL == srp) {
1249                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1250                 if (SRpnt)
1251                         scsi_release_request(SRpnt);
1252                 return;
1253         }
1254         sfp = srp->parentfp;
1255         if (sfp)
1256                 sdp = sfp->parentdp;
1257         if ((NULL == sdp) || sdp->detached) {
1258                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1259                 scsi_release_request(SRpnt);
1260                 return;
1261         }
1262
1263         /* First transfer ownership of data buffers to sg_device object. */
1264         srp->data.k_use_sg = SRpnt->sr_use_sg;
1265         srp->data.sglist_len = SRpnt->sr_sglist_len;
1266         srp->data.bufflen = SRpnt->sr_bufflen;
1267         srp->data.buffer = SRpnt->sr_buffer;
1268         /* now clear out request structure */
1269         SRpnt->sr_use_sg = 0;
1270         SRpnt->sr_sglist_len = 0;
1271         SRpnt->sr_bufflen = 0;
1272         SRpnt->sr_buffer = NULL;
1273         SRpnt->sr_underflow = 0;
1274         SRpnt->sr_request->rq_disk = NULL; /* "sg" _disowns_ request blk */
1275
1276         srp->my_cmdp = NULL;
1277
1278         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1279                 sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
1280         srp->header.resid = SCpnt->resid;
1281         /* N.B. unit of duration changes here from jiffies to millisecs */
1282         srp->header.duration =
1283             jiffies_to_msecs(jiffies - srp->header.duration);
1284         if (0 != SRpnt->sr_result) {
1285                 memcpy(srp->sense_b, SRpnt->sr_sense_buffer,
1286                        sizeof (srp->sense_b));
1287                 srp->header.status = 0xff & SRpnt->sr_result;
1288                 srp->header.masked_status = status_byte(SRpnt->sr_result);
1289                 srp->header.msg_status = msg_byte(SRpnt->sr_result);
1290                 srp->header.host_status = host_byte(SRpnt->sr_result);
1291                 srp->header.driver_status = driver_byte(SRpnt->sr_result);
1292                 if ((sdp->sgdebug > 0) &&
1293                     ((CHECK_CONDITION == srp->header.masked_status) ||
1294                      (COMMAND_TERMINATED == srp->header.masked_status)))
1295                         print_req_sense("sg_cmd_done", SRpnt);
1296
1297                 /* Following if statement is a patch supplied by Eric Youngdale */
1298                 if (driver_byte(SRpnt->sr_result) != 0
1299                     && (SRpnt->sr_sense_buffer[0] & 0x7f) == 0x70
1300                     && (SRpnt->sr_sense_buffer[2] & 0xf) == UNIT_ATTENTION
1301                     && sdp->device->removable) {
1302                         /* Detected disc change. Set the bit - this may be used if */
1303                         /* there are filesystems using this device. */
1304                         sdp->device->changed = 1;
1305                 }
1306         }
1307         /* Rely on write phase to clean out srp status values, so no "else" */
1308
1309         scsi_release_request(SRpnt);
1310         SRpnt = NULL;
1311         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1312                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1313                 sg_finish_rem_req(srp);
1314                 srp = NULL;
1315                 if (NULL == sfp->headrp) {
1316                         SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1317                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1318                                 scsi_device_put(sdp->device);
1319                         }
1320                         sfp = NULL;
1321                 }
1322         } else if (srp && srp->orphan) {
1323                 if (sfp->keep_orphan)
1324                         srp->sg_io_owned = 0;
1325                 else {
1326                         sg_finish_rem_req(srp);
1327                         srp = NULL;
1328                 }
1329         }
1330         if (sfp && srp) {
1331                 /* Now wake up any sg_read() that is waiting for this packet. */
1332                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1333                 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1334                 srp->done = 1;
1335                 wake_up_interruptible(&sfp->read_wait);
1336                 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1337         }
1338 }
1339
1340 static struct file_operations sg_fops = {
1341         .owner = THIS_MODULE,
1342         .read = sg_read,
1343         .write = sg_write,
1344         .poll = sg_poll,
1345         .ioctl = sg_ioctl,
1346         .open = sg_open,
1347         .mmap = sg_mmap,
1348         .release = sg_release,
1349         .fasync = sg_fasync,
1350 };
1351
1352 static struct class_simple * sg_sysfs_class;
1353
1354 static int sg_sysfs_valid = 0;
1355
1356 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1357 {
1358         Sg_device *sdp;
1359         unsigned long iflags;
1360         void *old_sg_dev_arr = NULL;
1361         int k, error;
1362
1363         sdp = kmalloc(sizeof(Sg_device), GFP_KERNEL);
1364         if (!sdp) {
1365                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1366                 return -ENOMEM;
1367         }
1368
1369         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1370         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1371                 Sg_device **tmp_da;
1372                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1373                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1374
1375                 tmp_da = kmalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1376                 if (unlikely(!tmp_da))
1377                         goto expand_failed;
1378
1379                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1380                 memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
1381                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1382                 old_sg_dev_arr = sg_dev_arr;
1383                 sg_dev_arr = tmp_da;
1384                 sg_dev_max = tmp_dev_max;
1385         }
1386
1387         for (k = 0; k < sg_dev_max; k++)
1388                 if (!sg_dev_arr[k])
1389                         break;
1390         if (unlikely(k >= SG_MAX_DEVS))
1391                 goto overflow;
1392
1393         memset(sdp, 0, sizeof(*sdp));
1394         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1395         sprintf(disk->disk_name, "sg%d", k);
1396         disk->first_minor = k;
1397         sdp->disk = disk;
1398         sdp->device = scsidp;
1399         init_waitqueue_head(&sdp->o_excl_wait);
1400         sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
1401
1402         sg_nr_dev++;
1403         sg_dev_arr[k] = sdp;
1404         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1405         error = k;
1406
1407  out:
1408         if (error < 0)
1409                 kfree(sdp);
1410         kfree(old_sg_dev_arr);
1411         return error;
1412
1413  expand_failed:
1414         printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1415         error = -ENOMEM;
1416         goto out;
1417
1418  overflow:
1419         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1420         printk(KERN_WARNING
1421                "Unable to attach sg device <%d, %d, %d, %d> type=%d, minor "
1422                "number exceeds %d\n", scsidp->host->host_no, scsidp->channel,
1423                scsidp->id, scsidp->lun, scsidp->type, SG_MAX_DEVS - 1);
1424         error = -ENODEV;
1425         goto out;
1426 }
1427
1428 static int
1429 sg_add(struct class_device *cl_dev)
1430 {
1431         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1432         struct gendisk *disk;
1433         Sg_device *sdp = NULL;
1434         struct cdev * cdev = NULL;
1435         int error, k;
1436
1437         disk = alloc_disk(1);
1438         if (!disk) {
1439                 printk(KERN_WARNING "alloc_disk failed\n");
1440                 return -ENOMEM;
1441         }
1442         disk->major = SCSI_GENERIC_MAJOR;
1443
1444         error = -ENOMEM;
1445         cdev = cdev_alloc();
1446         if (!cdev) {
1447                 printk(KERN_WARNING "cdev_alloc failed\n");
1448                 goto out;
1449         }
1450         cdev->owner = THIS_MODULE;
1451         cdev->ops = &sg_fops;
1452
1453         error = sg_alloc(disk, scsidp);
1454         if (error < 0) {
1455                 printk(KERN_WARNING "sg_alloc failed\n");
1456                 goto out;
1457         }
1458         k = error;
1459         sdp = sg_dev_arr[k];
1460
1461         devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
1462                         S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
1463                         "%s/generic", scsidp->devfs_name);
1464         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1465         if (error) {
1466                 devfs_remove("%s/generic", scsidp->devfs_name);
1467                 goto out;
1468         }
1469         sdp->cdev = cdev;
1470         if (sg_sysfs_valid) {
1471                 struct class_device * sg_class_member;
1472
1473                 sg_class_member = class_simple_device_add(sg_sysfs_class,
1474                                 MKDEV(SCSI_GENERIC_MAJOR, k),
1475                                 cl_dev->dev, "%s",
1476                                 disk->disk_name);
1477                 if (IS_ERR(sg_class_member))
1478                         printk(KERN_WARNING "sg_add: "
1479                                 "class_simple_device_add failed\n");
1480                 class_set_devdata(sg_class_member, sdp);
1481                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1482                                           &sg_class_member->kobj, "generic");
1483                 if (error)
1484                         printk(KERN_ERR "sg_add: unable to make symlink "
1485                                         "'generic' back to sg%d\n", k);
1486         } else
1487                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1488
1489         printk(KERN_NOTICE
1490                "Attached scsi generic sg%d at scsi%d, channel"
1491                " %d, id %d, lun %d,  type %d\n", k,
1492                scsidp->host->host_no, scsidp->channel, scsidp->id,
1493                scsidp->lun, scsidp->type);
1494
1495         return 0;
1496
1497 out:
1498         put_disk(disk);
1499         if (cdev)
1500                 cdev_del(cdev);
1501         return error;
1502 }
1503
1504 static void
1505 sg_remove(struct class_device *cl_dev)
1506 {
1507         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1508         Sg_device *sdp = NULL;
1509         unsigned long iflags;
1510         Sg_fd *sfp;
1511         Sg_fd *tsfp;
1512         Sg_request *srp;
1513         Sg_request *tsrp;
1514         int k, delay;
1515
1516         if (NULL == sg_dev_arr)
1517                 return;
1518         delay = 0;
1519         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1520         for (k = 0; k < sg_dev_max; k++) {
1521                 sdp = sg_dev_arr[k];
1522                 if ((NULL == sdp) || (sdp->device != scsidp))
1523                         continue;       /* dirty but lowers nesting */
1524                 if (sdp->headfp) {
1525                         sdp->detached = 1;
1526                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1527                                 tsfp = sfp->nextfp;
1528                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1529                                         tsrp = srp->nextrp;
1530                                         if (sfp->closed || (0 == sg_srp_done(srp, sfp)))
1531                                                 sg_finish_rem_req(srp);
1532                                 }
1533                                 if (sfp->closed) {
1534                                         scsi_device_put(sdp->device);
1535                                         __sg_remove_sfp(sdp, sfp);
1536                                 } else {
1537                                         delay = 1;
1538                                         wake_up_interruptible(&sfp->read_wait);
1539                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1540                                                     POLL_HUP);
1541                                 }
1542                         }
1543                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1544                         if (NULL == sdp->headfp) {
1545                                 sg_dev_arr[k] = NULL;
1546                         }
1547                 } else {        /* nothing active, simple case */
1548                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1549                         sg_dev_arr[k] = NULL;
1550                 }
1551                 sg_nr_dev--;
1552                 break;
1553         }
1554         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1555
1556         if (sdp) {
1557                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1558                 class_simple_device_remove(MKDEV(SCSI_GENERIC_MAJOR, k));
1559                 cdev_del(sdp->cdev);
1560                 sdp->cdev = NULL;
1561                 devfs_remove("%s/generic", scsidp->devfs_name);
1562                 put_disk(sdp->disk);
1563                 sdp->disk = NULL;
1564                 if (NULL == sdp->headfp)
1565                         kfree((char *) sdp);
1566         }
1567
1568         if (delay)
1569                 msleep(10);     /* dirty detach so delay device destruction */
1570 }
1571
1572 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1573  * of sysfs parameters (which module_param doesn't yet support).
1574  * Sysfs parameters defined explicitly below.
1575  */
1576 module_param_named(def_reserved_size, def_reserved_size, int, 0);
1577 module_param_named(allow_dio, sg_allow_dio, int, 0);
1578
1579 MODULE_AUTHOR("Douglas Gilbert");
1580 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1581 MODULE_LICENSE("GPL");
1582 MODULE_VERSION(SG_VERSION_STR);
1583
1584 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1585 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1586
1587 static int __init
1588 init_sg(void)
1589 {
1590         int rc;
1591
1592         if (def_reserved_size >= 0)
1593                 sg_big_buff = def_reserved_size;
1594
1595         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1596                                     SG_MAX_DEVS, "sg");
1597         if (rc)
1598                 return rc;
1599         sg_sysfs_class = class_simple_create(THIS_MODULE, "scsi_generic");
1600         if ( IS_ERR(sg_sysfs_class) ) {
1601                 rc = PTR_ERR(sg_sysfs_class);
1602                 goto err_out;
1603         }
1604         sg_sysfs_valid = 1;
1605         rc = scsi_register_interface(&sg_interface);
1606         if (0 == rc) {
1607 #ifdef CONFIG_SCSI_PROC_FS
1608                 sg_proc_init();
1609 #endif                          /* CONFIG_SCSI_PROC_FS */
1610                 return 0;
1611         }
1612         class_simple_destroy(sg_sysfs_class);
1613 err_out:
1614         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1615         return rc;
1616 }
1617
1618 static void __exit
1619 exit_sg(void)
1620 {
1621 #ifdef CONFIG_SCSI_PROC_FS
1622         sg_proc_cleanup();
1623 #endif                          /* CONFIG_SCSI_PROC_FS */
1624         scsi_unregister_interface(&sg_interface);
1625         class_simple_destroy(sg_sysfs_class);
1626         sg_sysfs_valid = 0;
1627         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1628                                  SG_MAX_DEVS);
1629         if (sg_dev_arr != NULL) {
1630                 kfree((char *) sg_dev_arr);
1631                 sg_dev_arr = NULL;
1632         }
1633         sg_dev_max = 0;
1634 }
1635
1636 static int
1637 sg_start_req(Sg_request * srp)
1638 {
1639         int res;
1640         Sg_fd *sfp = srp->parentfp;
1641         sg_io_hdr_t *hp = &srp->header;
1642         int dxfer_len = (int) hp->dxfer_len;
1643         int dxfer_dir = hp->dxfer_direction;
1644         Sg_scatter_hold *req_schp = &srp->data;
1645         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1646
1647         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1648         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1649                 return 0;
1650         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1651             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1652             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1653                 res = sg_build_direct(srp, sfp, dxfer_len);
1654                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1655                         return res;
1656         }
1657         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1658                 sg_link_reserve(sfp, srp, dxfer_len);
1659         else {
1660                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1661                 if (res) {
1662                         sg_remove_scat(req_schp);
1663                         return res;
1664                 }
1665         }
1666         return 0;
1667 }
1668
1669 static void
1670 sg_finish_rem_req(Sg_request * srp)
1671 {
1672         Sg_fd *sfp = srp->parentfp;
1673         Sg_scatter_hold *req_schp = &srp->data;
1674
1675         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1676         if (srp->res_used)
1677                 sg_unlink_reserve(sfp, srp);
1678         else
1679                 sg_remove_scat(req_schp);
1680         sg_remove_request(sfp, srp);
1681 }
1682
1683 static int
1684 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1685 {
1686         int ret_sz;
1687         int elem_sz = sizeof (struct scatterlist);
1688         int sg_bufflen = tablesize * elem_sz;
1689         int mx_sc_elems = tablesize;
1690
1691         schp->buffer = sg_page_malloc(sg_bufflen, sfp->low_dma, &ret_sz);
1692         if (!schp->buffer)
1693                 return -ENOMEM;
1694         else if (ret_sz != sg_bufflen) {
1695                 sg_bufflen = ret_sz;
1696                 mx_sc_elems = sg_bufflen / elem_sz;
1697         }
1698         schp->sglist_len = sg_bufflen;
1699         memset(schp->buffer, 0, sg_bufflen);
1700         return mx_sc_elems;     /* number of scat_gath elements allocated */
1701 }
1702
1703 #ifdef SG_ALLOW_DIO_CODE
1704 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1705         /* hopefully this generic code will moved to a library */
1706
1707 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1708    - mapping of all pages not successful
1709    - any page is above max_pfn
1710    (i.e., either completely successful or fails)
1711 */
1712 static int
1713 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1714                   unsigned long uaddr, size_t count, int rw,
1715                   unsigned long max_pfn)
1716 {
1717         int res, i, j;
1718         unsigned int nr_pages;
1719         struct page **pages;
1720
1721         nr_pages = ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT;
1722
1723         /* User attempted Overflow! */
1724         if ((uaddr + count) < uaddr)
1725                 return -EINVAL;
1726
1727         /* Too big */
1728         if (nr_pages > max_pages)
1729                 return -ENOMEM;
1730
1731         /* Hmm? */
1732         if (count == 0)
1733                 return 0;
1734
1735         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1736                 return -ENOMEM;
1737
1738         /* Try to fault in all of the necessary pages */
1739         down_read(&current->mm->mmap_sem);
1740         /* rw==READ means read from drive, write into memory area */
1741         res = get_user_pages(
1742                 current,
1743                 current->mm,
1744                 uaddr,
1745                 nr_pages,
1746                 rw == READ,
1747                 0, /* don't force */
1748                 pages,
1749                 NULL);
1750         up_read(&current->mm->mmap_sem);
1751
1752         /* Errors and no page mapped should return here */
1753         if (res < nr_pages)
1754                 goto out_unmap;
1755
1756         for (i=0; i < nr_pages; i++) {
1757                 /* FIXME: flush superflous for rw==READ,
1758                  * probably wrong function for rw==WRITE
1759                  */
1760                 flush_dcache_page(pages[i]);
1761                 if (page_to_pfn(pages[i]) > max_pfn)
1762                         goto out_unlock;
1763                 /* ?? Is locking needed? I don't think so */
1764                 /* if (TestSetPageLocked(pages[i]))
1765                    goto out_unlock; */
1766         }
1767
1768         /* Populate the scatter/gather list */
1769         sgl[0].page = pages[0];
1770         sgl[0].offset = uaddr & ~PAGE_MASK;
1771         if (nr_pages > 1) {
1772                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1773                 count -= sgl[0].length;
1774                 for (i=1; i < nr_pages ; i++) {
1775                         sgl[i].offset = 0;
1776                         sgl[i].page = pages[i];
1777                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1778                         count -= PAGE_SIZE;
1779                 }
1780         }
1781         else {
1782                 sgl[0].length = count;
1783         }
1784
1785         kfree(pages);
1786         return nr_pages;
1787
1788  out_unlock:
1789         /* for (j=0; j < i; j++)
1790            unlock_page(pages[j]); */
1791         res = 0;
1792  out_unmap:
1793         if (res > 0)
1794                 for (j=0; j < res; j++)
1795                         page_cache_release(pages[j]);
1796         kfree(pages);
1797         return res;
1798 }
1799
1800
1801 /* And unmap them... */
1802 static int
1803 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1804                     int dirtied)
1805 {
1806         int i;
1807
1808         for (i=0; i < nr_pages; i++) {
1809                 if (dirtied && !PageReserved(sgl[i].page))
1810                         SetPageDirty(sgl[i].page);
1811                 /* unlock_page(sgl[i].page); */
1812                 /* FIXME: cache flush missing for rw==READ
1813                  * FIXME: call the correct reference counting function
1814                  */
1815                 page_cache_release(sgl[i].page);
1816         }
1817
1818         return 0;
1819 }
1820
1821 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1822 #endif
1823
1824
1825 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1826 static int
1827 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1828 {
1829 #ifdef SG_ALLOW_DIO_CODE
1830         sg_io_hdr_t *hp = &srp->header;
1831         Sg_scatter_hold *schp = &srp->data;
1832         int sg_tablesize = sfp->parentdp->sg_tablesize;
1833         struct scatterlist *sgl;
1834         int mx_sc_elems, res;
1835         struct scsi_device *sdev = sfp->parentdp->device;
1836
1837         if (((unsigned long)hp->dxferp &
1838                         queue_dma_alignment(sdev->request_queue)) != 0)
1839                 return 1;
1840         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1841         if (mx_sc_elems <= 0) {
1842                 return 1;
1843         }
1844         sgl = (struct scatterlist *)schp->buffer;
1845         res = st_map_user_pages(sgl, mx_sc_elems, (unsigned long)hp->dxferp, dxfer_len,
1846                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0, ULONG_MAX);
1847         if (res <= 0)
1848                 return 1;
1849         schp->k_use_sg = res;
1850         schp->dio_in_use = 1;
1851         hp->info |= SG_INFO_DIRECT_IO;
1852         return 0;
1853 #else
1854         return 1;
1855 #endif
1856 }
1857
1858 static int
1859 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1860 {
1861         int ret_sz;
1862         int blk_size = buff_size;
1863         unsigned char *p = NULL;
1864
1865         if ((blk_size < 0) || (!sfp))
1866                 return -EFAULT;
1867         if (0 == blk_size)
1868                 ++blk_size;     /* don't know why */
1869 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1870         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1871         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1872                                    buff_size, blk_size));
1873         if (blk_size <= SG_SCATTER_SZ) {
1874                 p = sg_page_malloc(blk_size, sfp->low_dma, &ret_sz);
1875                 if (!p)
1876                         return -ENOMEM;
1877                 if (blk_size == ret_sz) {       /* got it on the first attempt */
1878                         schp->k_use_sg = 0;
1879                         schp->buffer = p;
1880                         schp->bufflen = blk_size;
1881                         schp->b_malloc_len = blk_size;
1882                         return 0;
1883                 }
1884         } else {
1885                 p = sg_page_malloc(SG_SCATTER_SZ, sfp->low_dma, &ret_sz);
1886                 if (!p)
1887                         return -ENOMEM;
1888         }
1889 /* Want some local declarations, so start new block ... */
1890         {                       /* lets try and build a scatter gather list */
1891                 struct scatterlist *sclp;
1892                 int k, rem_sz, num;
1893                 int mx_sc_elems;
1894                 int sg_tablesize = sfp->parentdp->sg_tablesize;
1895                 int first = 1;
1896
1897                 /* N.B. ret_sz carried into this block ... */
1898                 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1899                 if (mx_sc_elems < 0)
1900                         return mx_sc_elems;     /* most likely -ENOMEM */
1901
1902                 for (k = 0, sclp = schp->buffer, rem_sz = blk_size;
1903                      (rem_sz > 0) && (k < mx_sc_elems);
1904                      ++k, rem_sz -= ret_sz, ++sclp) {
1905                         if (first)
1906                                 first = 0;
1907                         else {
1908                                 num =
1909                                     (rem_sz >
1910                                      SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1911                                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1912                                 if (!p)
1913                                         break;
1914                         }
1915                         sclp->page = virt_to_page(p);
1916                         sclp->offset = offset_in_page(p);
1917                         sclp->length = ret_sz;
1918
1919                         SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1920                                           k, sg_scatg2virt(sclp), ret_sz));
1921                 }               /* end of for loop */
1922                 schp->k_use_sg = k;
1923                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1924                 schp->bufflen = blk_size;
1925                 if (rem_sz > 0) /* must have failed */
1926                         return -ENOMEM;
1927         }
1928         return 0;
1929 }
1930
1931 static int
1932 sg_write_xfer(Sg_request * srp)
1933 {
1934         sg_io_hdr_t *hp = &srp->header;
1935         Sg_scatter_hold *schp = &srp->data;
1936         int num_xfer = 0;
1937         int j, k, onum, usglen, ksglen, res;
1938         int iovec_count = (int) hp->iovec_count;
1939         int dxfer_dir = hp->dxfer_direction;
1940         unsigned char *p;
1941         unsigned char __user *up;
1942         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1943
1944         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1945             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1946                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1947                 if (schp->bufflen < num_xfer)
1948                         num_xfer = schp->bufflen;
1949         }
1950         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1951             (new_interface
1952              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1953                 return 0;
1954
1955         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1956                           num_xfer, iovec_count, schp->k_use_sg));
1957         if (iovec_count) {
1958                 onum = iovec_count;
1959                 if ((k = verify_area(VERIFY_READ, hp->dxferp,
1960                                      SZ_SG_IOVEC * onum)))
1961                         return k;
1962         } else
1963                 onum = 1;
1964
1965         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
1966                 for (j = 0, p = schp->buffer; j < onum; ++j) {
1967                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1968                         if (res)
1969                                 return res;
1970                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
1971                         if (__copy_from_user(p, up, usglen))
1972                                 return -EFAULT;
1973                         p += usglen;
1974                         num_xfer -= usglen;
1975                         if (num_xfer <= 0)
1976                                 return 0;
1977                 }
1978         } else {                /* kernel using scatter gather list */
1979                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
1980
1981                 ksglen = (int) sclp->length;
1982                 p = sg_scatg2virt(sclp);
1983                 for (j = 0, k = 0; j < onum; ++j) {
1984                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1985                         if (res)
1986                                 return res;
1987
1988                         for (; p; ++sclp, ksglen = (int) sclp->length,
1989                                   p = sg_scatg2virt(sclp)) {
1990                                 if (usglen <= 0)
1991                                         break;
1992                                 if (ksglen > usglen) {
1993                                         if (usglen >= num_xfer) {
1994                                                 if (__copy_from_user
1995                                                     (p, up, num_xfer))
1996                                                         return -EFAULT;
1997                                                 return 0;
1998                                         }
1999                                         if (__copy_from_user(p, up, usglen))
2000                                                 return -EFAULT;
2001                                         p += usglen;
2002                                         ksglen -= usglen;
2003                                         break;
2004                                 } else {
2005                                         if (ksglen >= num_xfer) {
2006                                                 if (__copy_from_user
2007                                                     (p, up, num_xfer))
2008                                                         return -EFAULT;
2009                                                 return 0;
2010                                         }
2011                                         if (__copy_from_user(p, up, ksglen))
2012                                                 return -EFAULT;
2013                                         up += ksglen;
2014                                         usglen -= ksglen;
2015                                 }
2016                                 ++k;
2017                                 if (k >= schp->k_use_sg)
2018                                         return 0;
2019                         }
2020                 }
2021         }
2022         return 0;
2023 }
2024
2025 static int
2026 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
2027            int wr_xf, int *countp, unsigned char __user **up)
2028 {
2029         int num_xfer = (int) hp->dxfer_len;
2030         unsigned char __user *p = hp->dxferp;
2031         int count, k;
2032
2033         if (0 == sg_num) {
2034                 if (wr_xf && ('\0' == hp->interface_id))
2035                         count = (int) hp->flags;        /* holds "old" input_size */
2036                 else
2037                         count = num_xfer;
2038         } else {
2039                 sg_iovec_t iovec;
2040                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
2041                         return -EFAULT;
2042                 p = iovec.iov_base;
2043                 count = (int) iovec.iov_len;
2044         }
2045         if ((k = verify_area(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count)))
2046                 return k;
2047         if (up)
2048                 *up = p;
2049         if (countp)
2050                 *countp = count;
2051         return 0;
2052 }
2053
2054 static void
2055 sg_remove_scat(Sg_scatter_hold * schp)
2056 {
2057         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2058         if (schp->buffer && (schp->sglist_len > 0)) {
2059                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2060
2061                 if (schp->dio_in_use) {
2062 #ifdef SG_ALLOW_DIO_CODE
2063                         st_unmap_user_pages(sclp, schp->k_use_sg, TRUE);
2064 #endif
2065                 } else {
2066                         int k;
2067
2068                         for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2069                              ++k, ++sclp) {
2070                                 SCSI_LOG_TIMEOUT(5, printk(
2071                                     "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
2072                                     k, sg_scatg2virt(sclp), sclp->length));
2073                                 sg_page_free(sg_scatg2virt(sclp), sclp->length);
2074                                 sclp->page = NULL;
2075                                 sclp->offset = 0;
2076                                 sclp->length = 0;
2077                         }
2078                 }
2079                 sg_page_free(schp->buffer, schp->sglist_len);
2080         } else if (schp->buffer)
2081                 sg_page_free(schp->buffer, schp->b_malloc_len);
2082         memset(schp, 0, sizeof (*schp));
2083 }
2084
2085 static int
2086 sg_read_xfer(Sg_request * srp)
2087 {
2088         sg_io_hdr_t *hp = &srp->header;
2089         Sg_scatter_hold *schp = &srp->data;
2090         int num_xfer = 0;
2091         int j, k, onum, usglen, ksglen, res;
2092         int iovec_count = (int) hp->iovec_count;
2093         int dxfer_dir = hp->dxfer_direction;
2094         unsigned char *p;
2095         unsigned char __user *up;
2096         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2097
2098         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2099             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2100                 num_xfer = hp->dxfer_len;
2101                 if (schp->bufflen < num_xfer)
2102                         num_xfer = schp->bufflen;
2103         }
2104         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2105             (new_interface
2106              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2107                 return 0;
2108
2109         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2110                           num_xfer, iovec_count, schp->k_use_sg));
2111         if (iovec_count) {
2112                 onum = iovec_count;
2113                 if ((k = verify_area(VERIFY_READ, hp->dxferp,
2114                                      SZ_SG_IOVEC * onum)))
2115                         return k;
2116         } else
2117                 onum = 1;
2118
2119         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
2120                 for (j = 0, p = schp->buffer; j < onum; ++j) {
2121                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2122                         if (res)
2123                                 return res;
2124                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
2125                         if (__copy_to_user(up, p, usglen))
2126                                 return -EFAULT;
2127                         p += usglen;
2128                         num_xfer -= usglen;
2129                         if (num_xfer <= 0)
2130                                 return 0;
2131                 }
2132         } else {                /* kernel using scatter gather list */
2133                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2134
2135                 ksglen = (int) sclp->length;
2136                 p = sg_scatg2virt(sclp);
2137                 for (j = 0, k = 0; j < onum; ++j) {
2138                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2139                         if (res)
2140                                 return res;
2141
2142                         for (; p; ++sclp, ksglen = (int) sclp->length,
2143                                   p = sg_scatg2virt(sclp)) {
2144                                 if (usglen <= 0)
2145                                         break;
2146                                 if (ksglen > usglen) {
2147                                         if (usglen >= num_xfer) {
2148                                                 if (__copy_to_user
2149                                                     (up, p, num_xfer))
2150                                                         return -EFAULT;
2151                                                 return 0;
2152                                         }
2153                                         if (__copy_to_user(up, p, usglen))
2154                                                 return -EFAULT;
2155                                         p += usglen;
2156                                         ksglen -= usglen;
2157                                         break;
2158                                 } else {
2159                                         if (ksglen >= num_xfer) {
2160                                                 if (__copy_to_user
2161                                                     (up, p, num_xfer))
2162                                                         return -EFAULT;
2163                                                 return 0;
2164                                         }
2165                                         if (__copy_to_user(up, p, ksglen))
2166                                                 return -EFAULT;
2167                                         up += ksglen;
2168                                         usglen -= ksglen;
2169                                 }
2170                                 ++k;
2171                                 if (k >= schp->k_use_sg)
2172                                         return 0;
2173                         }
2174                 }
2175         }
2176         return 0;
2177 }
2178
2179 static int
2180 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2181 {
2182         Sg_scatter_hold *schp = &srp->data;
2183
2184         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2185                                    num_read_xfer));
2186         if ((!outp) || (num_read_xfer <= 0))
2187                 return 0;
2188         if (schp->k_use_sg > 0) {
2189                 int k, num;
2190                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2191
2192                 for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2193                      ++k, ++sclp) {
2194                         num = (int) sclp->length;
2195                         if (num > num_read_xfer) {
2196                                 if (__copy_to_user
2197                                     (outp, sg_scatg2virt(sclp), num_read_xfer))
2198                                         return -EFAULT;
2199                                 break;
2200                         } else {
2201                                 if (__copy_to_user
2202                                     (outp, sg_scatg2virt(sclp), num))
2203                                         return -EFAULT;
2204                                 num_read_xfer -= num;
2205                                 if (num_read_xfer <= 0)
2206                                         break;
2207                                 outp += num;
2208                         }
2209                 }
2210         } else {
2211                 if (__copy_to_user(outp, schp->buffer, num_read_xfer))
2212                         return -EFAULT;
2213         }
2214         return 0;
2215 }
2216
2217 static void
2218 sg_build_reserve(Sg_fd * sfp, int req_size)
2219 {
2220         Sg_scatter_hold *schp = &sfp->reserve;
2221
2222         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2223         do {
2224                 if (req_size < PAGE_SIZE)
2225                         req_size = PAGE_SIZE;
2226                 if (0 == sg_build_indirect(schp, sfp, req_size))
2227                         return;
2228                 else
2229                         sg_remove_scat(schp);
2230                 req_size >>= 1; /* divide by 2 */
2231         } while (req_size > (PAGE_SIZE / 2));
2232 }
2233
2234 static void
2235 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2236 {
2237         Sg_scatter_hold *req_schp = &srp->data;
2238         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2239
2240         srp->res_used = 1;
2241         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2242         size = (size + 1) & (~1);       /* round to even for aha1542 */
2243         if (rsv_schp->k_use_sg > 0) {
2244                 int k, num;
2245                 int rem = size;
2246                 struct scatterlist *sclp =
2247                     (struct scatterlist *) rsv_schp->buffer;
2248
2249                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
2250                         num = (int) sclp->length;
2251                         if (rem <= num) {
2252                                 if (0 == k) {
2253                                         req_schp->k_use_sg = 0;
2254                                         req_schp->buffer = sg_scatg2virt(sclp);
2255                                 } else {
2256                                         sfp->save_scat_len = num;
2257                                         sclp->length = (unsigned) rem;
2258                                         req_schp->k_use_sg = k + 1;
2259                                         req_schp->sglist_len =
2260                                             rsv_schp->sglist_len;
2261                                         req_schp->buffer = rsv_schp->buffer;
2262                                 }
2263                                 req_schp->bufflen = size;
2264                                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2265                                 break;
2266                         } else
2267                                 rem -= num;
2268                 }
2269                 if (k >= rsv_schp->k_use_sg)
2270                         SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2271         } else {
2272                 req_schp->k_use_sg = 0;
2273                 req_schp->bufflen = size;
2274                 req_schp->buffer = rsv_schp->buffer;
2275                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2276         }
2277 }
2278
2279 static void
2280 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2281 {
2282         Sg_scatter_hold *req_schp = &srp->data;
2283         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2284
2285         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2286                                    (int) req_schp->k_use_sg));
2287         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2288                 struct scatterlist *sclp =
2289                     (struct scatterlist *) rsv_schp->buffer;
2290
2291                 if (sfp->save_scat_len > 0)
2292                         (sclp + (req_schp->k_use_sg - 1))->length =
2293                             (unsigned) sfp->save_scat_len;
2294                 else
2295                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2296         }
2297         req_schp->k_use_sg = 0;
2298         req_schp->bufflen = 0;
2299         req_schp->buffer = NULL;
2300         req_schp->sglist_len = 0;
2301         sfp->save_scat_len = 0;
2302         srp->res_used = 0;
2303 }
2304
2305 static Sg_request *
2306 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2307 {
2308         Sg_request *resp;
2309         unsigned long iflags;
2310
2311         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2312         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2313                 /* look for requests that are ready + not SG_IO owned */
2314                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2315                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2316                         resp->done = 2; /* guard against other readers */
2317                         break;
2318                 }
2319         }
2320         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2321         return resp;
2322 }
2323
2324 #ifdef CONFIG_SCSI_PROC_FS
2325 static Sg_request *
2326 sg_get_nth_request(Sg_fd * sfp, int nth)
2327 {
2328         Sg_request *resp;
2329         unsigned long iflags;
2330         int k;
2331
2332         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2333         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2334              ++k, resp = resp->nextrp) ;
2335         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2336         return resp;
2337 }
2338 #endif
2339
2340 /* always adds to end of list */
2341 static Sg_request *
2342 sg_add_request(Sg_fd * sfp)
2343 {
2344         int k;
2345         unsigned long iflags;
2346         Sg_request *resp;
2347         Sg_request *rp = sfp->req_arr;
2348
2349         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2350         resp = sfp->headrp;
2351         if (!resp) {
2352                 memset(rp, 0, sizeof (Sg_request));
2353                 rp->parentfp = sfp;
2354                 resp = rp;
2355                 sfp->headrp = resp;
2356         } else {
2357                 if (0 == sfp->cmd_q)
2358                         resp = NULL;    /* command queuing disallowed */
2359                 else {
2360                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2361                                 if (!rp->parentfp)
2362                                         break;
2363                         }
2364                         if (k < SG_MAX_QUEUE) {
2365                                 memset(rp, 0, sizeof (Sg_request));
2366                                 rp->parentfp = sfp;
2367                                 while (resp->nextrp)
2368                                         resp = resp->nextrp;
2369                                 resp->nextrp = rp;
2370                                 resp = rp;
2371                         } else
2372                                 resp = NULL;
2373                 }
2374         }
2375         if (resp) {
2376                 resp->nextrp = NULL;
2377                 resp->header.duration = jiffies;
2378                 resp->my_cmdp = NULL;
2379         }
2380         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2381         return resp;
2382 }
2383
2384 /* Return of 1 for found; 0 for not found */
2385 static int
2386 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2387 {
2388         Sg_request *prev_rp;
2389         Sg_request *rp;
2390         unsigned long iflags;
2391         int res = 0;
2392
2393         if ((!sfp) || (!srp) || (!sfp->headrp))
2394                 return res;
2395         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2396         prev_rp = sfp->headrp;
2397         if (srp == prev_rp) {
2398                 sfp->headrp = prev_rp->nextrp;
2399                 prev_rp->parentfp = NULL;
2400                 res = 1;
2401         } else {
2402                 while ((rp = prev_rp->nextrp)) {
2403                         if (srp == rp) {
2404                                 prev_rp->nextrp = rp->nextrp;
2405                                 rp->parentfp = NULL;
2406                                 res = 1;
2407                                 break;
2408                         }
2409                         prev_rp = rp;
2410                 }
2411         }
2412         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2413         return res;
2414 }
2415
2416 #ifdef CONFIG_SCSI_PROC_FS
2417 static Sg_fd *
2418 sg_get_nth_sfp(Sg_device * sdp, int nth)
2419 {
2420         Sg_fd *resp;
2421         unsigned long iflags;
2422         int k;
2423
2424         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2425         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2426              ++k, resp = resp->nextfp) ;
2427         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2428         return resp;
2429 }
2430 #endif
2431
2432 static Sg_fd *
2433 sg_add_sfp(Sg_device * sdp, int dev)
2434 {
2435         Sg_fd *sfp;
2436         unsigned long iflags;
2437
2438         sfp = (Sg_fd *) sg_page_malloc(sizeof (Sg_fd), 0, NULL);
2439         if (!sfp)
2440                 return NULL;
2441         memset(sfp, 0, sizeof (Sg_fd));
2442         init_waitqueue_head(&sfp->read_wait);
2443         rwlock_init(&sfp->rq_list_lock);
2444
2445         sfp->timeout = SG_DEFAULT_TIMEOUT;
2446         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2447         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2448         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2449             sdp->device->host->unchecked_isa_dma : 1;
2450         sfp->cmd_q = SG_DEF_COMMAND_Q;
2451         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2452         sfp->parentdp = sdp;
2453         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2454         if (!sdp->headfp)
2455                 sdp->headfp = sfp;
2456         else {                  /* add to tail of existing list */
2457                 Sg_fd *pfp = sdp->headfp;
2458                 while (pfp->nextfp)
2459                         pfp = pfp->nextfp;
2460                 pfp->nextfp = sfp;
2461         }
2462         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2463         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2464         sg_build_reserve(sfp, sg_big_buff);
2465         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2466                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2467         return sfp;
2468 }
2469
2470 static void
2471 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2472 {
2473         Sg_fd *fp;
2474         Sg_fd *prev_fp;
2475
2476         prev_fp = sdp->headfp;
2477         if (sfp == prev_fp)
2478                 sdp->headfp = prev_fp->nextfp;
2479         else {
2480                 while ((fp = prev_fp->nextfp)) {
2481                         if (sfp == fp) {
2482                                 prev_fp->nextfp = fp->nextfp;
2483                                 break;
2484                         }
2485                         prev_fp = fp;
2486                 }
2487         }
2488         if (sfp->reserve.bufflen > 0) {
2489                 SCSI_LOG_TIMEOUT(6,
2490                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2491                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2492                 if (sfp->mmap_called)
2493                         sg_rb_correct4mmap(&sfp->reserve, 0);   /* undo correction */
2494                 sg_remove_scat(&sfp->reserve);
2495         }
2496         sfp->parentdp = NULL;
2497         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2498         sg_page_free((char *) sfp, sizeof (Sg_fd));
2499 }
2500
2501 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2502 static int
2503 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2504 {
2505         Sg_request *srp;
2506         Sg_request *tsrp;
2507         int dirty = 0;
2508         int res = 0;
2509
2510         for (srp = sfp->headrp; srp; srp = tsrp) {
2511                 tsrp = srp->nextrp;
2512                 if (sg_srp_done(srp, sfp))
2513                         sg_finish_rem_req(srp);
2514                 else
2515                         ++dirty;
2516         }
2517         if (0 == dirty) {
2518                 unsigned long iflags;
2519
2520                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2521                 __sg_remove_sfp(sdp, sfp);
2522                 if (sdp->detached && (NULL == sdp->headfp)) {
2523                         int k, maxd;
2524
2525                         maxd = sg_dev_max;
2526                         for (k = 0; k < maxd; ++k) {
2527                                 if (sdp == sg_dev_arr[k])
2528                                         break;
2529                         }
2530                         if (k < maxd)
2531                                 sg_dev_arr[k] = NULL;
2532                         kfree((char *) sdp);
2533                         res = 1;
2534                 }
2535                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2536         } else {
2537                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2538                 /* only bump the access_count if we actually succeeded in
2539                  * throwing another counter on the host module */
2540                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2541                 sfp->closed = 1;        /* flag dirty state on this fd */
2542                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2543                                   dirty));
2544         }
2545         return res;
2546 }
2547
2548 static int
2549 sg_res_in_use(Sg_fd * sfp)
2550 {
2551         const Sg_request *srp;
2552         unsigned long iflags;
2553
2554         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2555         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2556                 if (srp->res_used)
2557                         break;
2558         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2559         return srp ? 1 : 0;
2560 }
2561
2562 /* If retSzp==NULL want exact size or fail */
2563 static char *
2564 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2565 {
2566         char *resp = NULL;
2567         int page_mask;
2568         int order, a_size;
2569         int resSz = rqSz;
2570
2571         if (rqSz <= 0)
2572                 return resp;
2573
2574         if (lowDma)
2575                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
2576         else
2577                 page_mask = GFP_ATOMIC | __GFP_NOWARN;
2578
2579         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2580              order++, a_size <<= 1) ;
2581         resp = (char *) __get_free_pages(page_mask, order);
2582         while ((!resp) && order && retSzp) {
2583                 --order;
2584                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2585                 resp = (char *) __get_free_pages(page_mask, order);     /* try half */
2586                 resSz = a_size;
2587         }
2588         if (resp) {
2589                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2590                         memset(resp, 0, resSz);
2591                 if (retSzp)
2592                         *retSzp = resSz;
2593         }
2594         return resp;
2595 }
2596
2597 static void
2598 sg_page_free(char *buff, int size)
2599 {
2600         int order, a_size;
2601
2602         if (!buff)
2603                 return;
2604         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2605              order++, a_size <<= 1) ;
2606         free_pages((unsigned long) buff, order);
2607 }
2608
2609 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2610         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2611         MODE_SENSE, MODE_SENSE_10, LOG_SENSE
2612 };
2613
2614 static int
2615 sg_allow_access(unsigned char opcode, char dev_type)
2616 {
2617         int k;
2618
2619         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2620                 return 1;
2621         for (k = 0; k < sizeof (allow_ops); ++k) {
2622                 if (opcode == allow_ops[k])
2623                         return 1;
2624         }
2625         return 0;
2626 }
2627
2628 #ifdef CONFIG_SCSI_PROC_FS
2629 static int
2630 sg_last_dev(void)
2631 {
2632         int k;
2633         unsigned long iflags;
2634
2635         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2636         for (k = sg_dev_max - 1; k >= 0; --k)
2637                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2638                         break;
2639         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2640         return k + 1;           /* origin 1 */
2641 }
2642 #endif
2643
2644 static Sg_device *
2645 sg_get_dev(int dev)
2646 {
2647         Sg_device *sdp = NULL;
2648         unsigned long iflags;
2649
2650         if (sg_dev_arr && (dev >= 0)) {
2651                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2652                 if (dev < sg_dev_max)
2653                         sdp = sg_dev_arr[dev];
2654                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2655         }
2656         return sdp;
2657 }
2658
2659 #ifdef CONFIG_SCSI_PROC_FS
2660
2661 static struct proc_dir_entry *sg_proc_sgp = NULL;
2662
2663 static char sg_proc_sg_dirname[] = "scsi/sg";
2664
2665 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2666
2667 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2668 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2669                                   size_t count, loff_t *off);
2670 static struct file_operations adio_fops = {
2671         /* .owner, .read and .llseek added in sg_proc_init() */
2672         .open = sg_proc_single_open_adio,
2673         .write = sg_proc_write_adio,
2674         .release = single_release,
2675 };
2676
2677 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2678 static ssize_t sg_proc_write_dressz(struct file *filp,
2679                 const char __user *buffer, size_t count, loff_t *off);
2680 static struct file_operations dressz_fops = {
2681         .open = sg_proc_single_open_dressz,
2682         .write = sg_proc_write_dressz,
2683         .release = single_release,
2684 };
2685
2686 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2687 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2688 static struct file_operations version_fops = {
2689         .open = sg_proc_single_open_version,
2690         .release = single_release,
2691 };
2692
2693 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2694 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2695 static struct file_operations devhdr_fops = {
2696         .open = sg_proc_single_open_devhdr,
2697         .release = single_release,
2698 };
2699
2700 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2701 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2702 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2703 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2704 static void dev_seq_stop(struct seq_file *s, void *v);
2705 static struct file_operations dev_fops = {
2706         .open = sg_proc_open_dev,
2707         .release = seq_release,
2708 };
2709 static struct seq_operations dev_seq_ops = {
2710         .start = dev_seq_start,
2711         .next  = dev_seq_next,
2712         .stop  = dev_seq_stop,
2713         .show  = sg_proc_seq_show_dev,
2714 };
2715
2716 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2717 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2718 static struct file_operations devstrs_fops = {
2719         .open = sg_proc_open_devstrs,
2720         .release = seq_release,
2721 };
2722 static struct seq_operations devstrs_seq_ops = {
2723         .start = dev_seq_start,
2724         .next  = dev_seq_next,
2725         .stop  = dev_seq_stop,
2726         .show  = sg_proc_seq_show_devstrs,
2727 };
2728
2729 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2730 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2731 static struct file_operations debug_fops = {
2732         .open = sg_proc_open_debug,
2733         .release = seq_release,
2734 };
2735 static struct seq_operations debug_seq_ops = {
2736         .start = dev_seq_start,
2737         .next  = dev_seq_next,
2738         .stop  = dev_seq_stop,
2739         .show  = sg_proc_seq_show_debug,
2740 };
2741
2742
2743 struct sg_proc_leaf {
2744         const char * name;
2745         struct file_operations * fops;
2746 };
2747
2748 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2749         {"allow_dio", &adio_fops},
2750         {"debug", &debug_fops},
2751         {"def_reserved_size", &dressz_fops},
2752         {"device_hdr", &devhdr_fops},
2753         {"devices", &dev_fops},
2754         {"device_strs", &devstrs_fops},
2755         {"version", &version_fops}
2756 };
2757
2758 static int
2759 sg_proc_init(void)
2760 {
2761         int k, mask;
2762         int num_leaves =
2763             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2764         struct proc_dir_entry *pdep;
2765         struct sg_proc_leaf * leaf;
2766
2767         sg_proc_sgp = create_proc_entry(sg_proc_sg_dirname,
2768                                         S_IFDIR | S_IRUGO | S_IXUGO, NULL);
2769         if (!sg_proc_sgp)
2770                 return 1;
2771         for (k = 0; k < num_leaves; ++k) {
2772                 leaf = &sg_proc_leaf_arr[k];
2773                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2774                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2775                 if (pdep) {
2776                         leaf->fops->owner = THIS_MODULE,
2777                         leaf->fops->read = seq_read,
2778                         leaf->fops->llseek = seq_lseek,
2779                         pdep->proc_fops = leaf->fops;
2780                 }
2781         }
2782         return 0;
2783 }
2784
2785 static void
2786 sg_proc_cleanup(void)
2787 {
2788         int k;
2789         int num_leaves =
2790             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2791
2792         if (!sg_proc_sgp)
2793                 return;
2794         for (k = 0; k < num_leaves; ++k)
2795                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2796         remove_proc_entry(sg_proc_sg_dirname, NULL);
2797 }
2798
2799
2800 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2801 {
2802         seq_printf(s, "%d\n", *((int *)s->private));
2803         return 0;
2804 }
2805
2806 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2807 {
2808         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2809 }
2810
2811 static ssize_t
2812 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2813                    size_t count, loff_t *off)
2814 {
2815         int num;
2816         char buff[11];
2817
2818         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2819                 return -EACCES;
2820         num = (count < 10) ? count : 10;
2821         if (copy_from_user(buff, buffer, num))
2822                 return -EFAULT;
2823         buff[num] = '\0';
2824         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2825         return count;
2826 }
2827
2828 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2829 {
2830         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2831 }
2832
2833 static ssize_t
2834 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2835                      size_t count, loff_t *off)
2836 {
2837         int num;
2838         unsigned long k = ULONG_MAX;
2839         char buff[11];
2840
2841         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2842                 return -EACCES;
2843         num = (count < 10) ? count : 10;
2844         if (copy_from_user(buff, buffer, num))
2845                 return -EFAULT;
2846         buff[num] = '\0';
2847         k = simple_strtoul(buff, NULL, 10);
2848         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2849                 sg_big_buff = k;
2850                 return count;
2851         }
2852         return -ERANGE;
2853 }
2854
2855 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2856 {
2857         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2858                    sg_version_date);
2859         return 0;
2860 }
2861
2862 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2863 {
2864         return single_open(file, sg_proc_seq_show_version, NULL);
2865 }
2866
2867 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2868 {
2869         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2870                    "online\n");
2871         return 0;
2872 }
2873
2874 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2875 {
2876         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2877 }
2878
2879 struct sg_proc_deviter {
2880         loff_t  index;
2881         size_t  max;
2882 };
2883
2884 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2885 {
2886         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2887
2888         if (! it)
2889                 return NULL;
2890         if (NULL == sg_dev_arr)
2891                 goto err1;
2892         it->index = *pos;
2893         it->max = sg_last_dev();
2894         if (it->index >= it->max)
2895                 goto err1;
2896         return it;
2897 err1:
2898         kfree(it);
2899         return NULL;
2900 }
2901
2902 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2903 {
2904         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2905
2906         *pos = ++it->index;
2907         return (it->index < it->max) ? it : NULL;
2908 }
2909
2910 static void dev_seq_stop(struct seq_file *s, void *v)
2911 {
2912         kfree (v);
2913 }
2914
2915 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2916 {
2917         return seq_open(file, &dev_seq_ops);
2918 }
2919
2920 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2921 {
2922         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2923         Sg_device *sdp;
2924         struct scsi_device *scsidp;
2925
2926         sdp = it ? sg_get_dev(it->index) : NULL;
2927         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2928                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2929                               scsidp->host->host_no, scsidp->channel,
2930                               scsidp->id, scsidp->lun, (int) scsidp->type,
2931                               1,
2932                               (int) scsidp->queue_depth,
2933                               (int) scsidp->device_busy,
2934                               (int) scsi_device_online(scsidp));
2935         else
2936                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2937         return 0;
2938 }
2939
2940 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2941 {
2942         return seq_open(file, &devstrs_seq_ops);
2943 }
2944
2945 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2946 {
2947         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2948         Sg_device *sdp;
2949         struct scsi_device *scsidp;
2950
2951         sdp = it ? sg_get_dev(it->index) : NULL;
2952         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2953                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2954                            scsidp->vendor, scsidp->model, scsidp->rev);
2955         else
2956                 seq_printf(s, "<no active device>\n");
2957         return 0;
2958 }
2959
2960 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2961 {
2962         int k, m, new_interface, blen, usg;
2963         Sg_request *srp;
2964         Sg_fd *fp;
2965         const sg_io_hdr_t *hp;
2966         const char * cp;
2967
2968         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2969                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2970                            "(res)sgat=%d low_dma=%d\n", k + 1,
2971                            jiffies_to_msecs(fp->timeout),
2972                            fp->reserve.bufflen,
2973                            (int) fp->reserve.k_use_sg,
2974                            (int) fp->low_dma);
2975                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2976                            (int) fp->cmd_q, (int) fp->force_packid,
2977                            (int) fp->keep_orphan, (int) fp->closed);
2978                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2979                         hp = &srp->header;
2980                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2981                         if (srp->res_used) {
2982                                 if (new_interface &&
2983                                     (SG_FLAG_MMAP_IO & hp->flags))
2984                                         cp = "     mmap>> ";
2985                                 else
2986                                         cp = "     rb>> ";
2987                         } else {
2988                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2989                                         cp = "     dio>> ";
2990                                 else
2991                                         cp = "     ";
2992                         }
2993                         seq_printf(s, cp);
2994                         blen = srp->my_cmdp ?
2995                                 srp->my_cmdp->sr_bufflen : srp->data.bufflen;
2996                         usg = srp->my_cmdp ?
2997                                 srp->my_cmdp->sr_use_sg : srp->data.k_use_sg;
2998                         seq_printf(s, srp->done ?
2999                                    ((1 == srp->done) ?  "rcv:" : "fin:")
3000                                    : (srp->my_cmdp ? "act:" : "prior:"));
3001                         seq_printf(s, " id=%d blen=%d",
3002                                    srp->header.pack_id, blen);
3003                         if (srp->done)
3004                                 seq_printf(s, " dur=%d", hp->duration);
3005                         else
3006                                 seq_printf(s, " t_o/elap=%d/%d",
3007                                   new_interface ? hp->timeout : jiffies_to_msecs(fp->timeout),
3008                                   jiffies_to_msecs(hp->duration ? (jiffies - hp->duration) : 0));
3009                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
3010                                    (int) srp->data.cmd_opcode);
3011                 }
3012                 if (0 == m)
3013                         seq_printf(s, "     No requests active\n");
3014         }
3015 }
3016
3017 static int sg_proc_open_debug(struct inode *inode, struct file *file)
3018 {
3019         return seq_open(file, &debug_seq_ops);
3020 }
3021
3022 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
3023 {
3024         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3025         Sg_device *sdp;
3026
3027         if (it && (0 == it->index)) {
3028                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
3029                            "(origin 1)\n", sg_dev_max, (int)it->max);
3030                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
3031         }
3032         sdp = it ? sg_get_dev(it->index) : NULL;
3033         if (sdp) {
3034                 struct scsi_device *scsidp = sdp->device;
3035
3036                 if (NULL == scsidp) {
3037                         seq_printf(s, "device %d detached ??\n",
3038                                    (int)it->index);
3039                         return 0;
3040                 }
3041
3042                 if (sg_get_nth_sfp(sdp, 0)) {
3043                         seq_printf(s, " >>> device=%s ",
3044                                 sdp->disk->disk_name);
3045                         if (sdp->detached)
3046                                 seq_printf(s, "detached pending close ");
3047                         else
3048                                 seq_printf
3049                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
3050                                      scsidp->host->host_no,
3051                                      scsidp->channel, scsidp->id,
3052                                      scsidp->lun,
3053                                      scsidp->host->hostt->emulated);
3054                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
3055                                    sdp->sg_tablesize, sdp->exclude);
3056                 }
3057                 sg_proc_debug_helper(s, sdp);
3058         }
3059         return 0;
3060 }
3061
3062 #endif                          /* CONFIG_SCSI_PROC_FS */
3063
3064 module_init(init_sg);
3065 module_exit(exit_sg);
3066 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);