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