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