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/vmalloc.h>
  46 #include <linux/smp_lock.h>
  47 #include <linux/moduleparam.h>
  48 #include <linux/devfs_fs_kernel.h>
  49 #include <linux/cdev.h>
  50 #include <linux/seq_file.h>
  51
  52 #include <linux/blkdev.h>
  53 #include "scsi.h"
  54 #include "hosts.h"
  55 #include <scsi/scsi_driver.h>
  56 #include <scsi/scsi_ioctl.h>
  57 #include <scsi/sg.h>
  58
  59 #include "scsi_logging.h"
  60
  61 #ifdef CONFIG_SCSI_PROC_FS
  62 #include <linux/proc_fs.h>
  63 static char *sg_version_date = "20040513";
  64
  65 static int sg_proc_init(void);
  66 static void sg_proc_cleanup(void);
  67 #endif
  68
  69 #ifndef LINUX_VERSION_CODE
  70 #include <linux/version.h>
  71 #endif                          /* LINUX_VERSION_CODE */
  72
  73 #define SG_ALLOW_DIO_DEF 0
  74 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
  75
  76 #define SG_MAX_DEVS 8192
  77
  78 /*
  79  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  80  * Then when using 32 bit integers x * m may overflow during the calculation.
  81  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  82  * calculates the same, but prevents the overflow when both m and d
  83  * are "small" numbers (like HZ and USER_HZ).
  84  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  85  * in 32 bits.
  86  */
  87 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  88
  89 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  90
  91 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  92 /* N.B. This variable is readable and writeable via
  93    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  94    of this size (or less if there is not enough memory) will be reserved
  95    for use by this file descriptor. [Deprecated usage: this variable is also
  96    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
  97    the kernel (i.e. it is not a module).] */
  98 static int def_reserved_size = -1;      /* picks up init parameter */
  99 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
 100
 101 #define SG_SECTOR_SZ 512
 102 #define SG_SECTOR_MSK (SG_SECTOR_SZ - 1)
 103
 104 #define SG_DEV_ARR_LUMP 32      /* amount to over allocate sg_dev_arr by */
 105
 106 static int sg_add(struct class_device *);
 107 static void sg_remove(struct class_device *);
 108
 109 static Scsi_Request *dummy_cmdp;        /* only used for sizeof */
 110
 111 static rwlock_t sg_dev_arr_lock = RW_LOCK_UNLOCKED;     /* Also used to lock
 112                                                            file descriptor list for device */
 113
 114 static struct class_interface sg_interface = {
 115         .add            = sg_add,
 116         .remove         = sg_remove,
 117 };
 118
 119 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 120         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 121         unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
 122         unsigned bufflen;       /* Size of (aggregate) data buffer */
 123         unsigned b_malloc_len;  /* actual len malloc'ed in buffer */
 124         void *buffer;           /* Data buffer or scatter list (k_use_sg>0) */
 125         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 126         unsigned char cmd_opcode; /* first byte of command */
 127 } Sg_scatter_hold;
 128
 129 struct sg_device;               /* forward declarations */
 130 struct sg_fd;
 131
 132 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 133         Scsi_Request *my_cmdp;  /* != 0  when request with lower levels */
 134         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 135         struct sg_fd *parentfp; /* NULL -> not in use */
 136         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 137         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 138         unsigned char sense_b[sizeof (dummy_cmdp->sr_sense_buffer)];
 139         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 140         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 141         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 142         volatile char done;     /* 0->before bh, 1->before read, 2->read */
 143 } Sg_request;
 144
 145 typedef struct sg_fd {          /* holds the state of a file descriptor */
 146         struct sg_fd *nextfp;   /* NULL when last opened fd on this device */
 147         struct sg_device *parentdp;     /* owning device */
 148         wait_queue_head_t read_wait;    /* queue read until command done */
 149         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 150         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 151         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 152         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 153         unsigned save_scat_len; /* original length of trunc. scat. element */
 154         Sg_request *headrp;     /* head of request slist, NULL->empty */
 155         struct fasync_struct *async_qp; /* used by asynchronous notification */
 156         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 157         char low_dma;           /* as in parent but possibly overridden to 1 */
 158         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 159         volatile char closed;   /* 1 -> fd closed but request(s) outstanding */
 160         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 161         char next_cmd_len;      /* 0 -> automatic (def), >0 -> use on next write() */
 162         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 163         char mmap_called;       /* 0 -> mmap() never called on this fd */
 164 } Sg_fd;
 165
 166 typedef struct sg_device { /* holds the state of each scsi generic device */
 167         struct scsi_device *device;
 168         wait_queue_head_t o_excl_wait;  /* queue open() when O_EXCL in use */
 169         int sg_tablesize;       /* adapter's max scatter-gather table size */
 170         Sg_fd *headfp;          /* first open fd belonging to this device */
 171         volatile char detached; /* 0->attached, 1->detached pending removal */
 172         volatile char exclude;  /* opened for exclusive access */
 173         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 174         struct gendisk *disk;
 175         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 176 } Sg_device;
 177
 178 static int sg_fasync(int fd, struct file *filp, int mode);
 179 static void sg_cmd_done(Scsi_Cmnd * SCpnt);     /* tasklet or soft irq callback */
 180 static int sg_start_req(Sg_request * srp);
 181 static void sg_finish_rem_req(Sg_request * srp);
 182 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 183 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
 184                          int tablesize);
 185 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 186                            Sg_request * srp);
 187 static ssize_t sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 188                             int blocking, int read_only, Sg_request ** o_srp);
 189 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 190                            unsigned char *cmnd, int timeout, int blocking);
 191 static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
 192                       int wr_xf, int *countp, unsigned char __user **up);
 193 static int sg_write_xfer(Sg_request * srp);
 194 static int sg_read_xfer(Sg_request * srp);
 195 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 196 static void sg_remove_scat(Sg_scatter_hold * schp);
 197 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 198 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 199 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 200 static char *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
 201 static void sg_page_free(char *buff, int size);
 202 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 203 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 204 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 205 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 206 static Sg_request *sg_add_request(Sg_fd * sfp);
 207 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 208 static int sg_res_in_use(Sg_fd * sfp);
 209 static int sg_ms_to_jif(unsigned int msecs);
 210 static inline unsigned sg_jif_to_ms(int jifs);
 211 static int sg_allow_access(unsigned char opcode, char dev_type);
 212 static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
 213 static Sg_device *sg_get_dev(int dev);
 214 static inline unsigned char *sg_scatg2virt(const struct scatterlist *sclp);
 215 #ifdef CONFIG_SCSI_PROC_FS
 216 static int sg_last_dev(void);
 217 #endif
 218
 219 static Sg_device **sg_dev_arr = NULL;
 220 static int sg_dev_max;
 221 static int sg_nr_dev;
 222
 223 #define SZ_SG_HEADER sizeof(struct sg_header)
 224 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 225 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 226 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 227
 228 static int
 229 sg_open(struct inode *inode, struct file *filp)
 230 {
 231         int dev = iminor(inode);
 232         int flags = filp->f_flags;
 233         Sg_device *sdp;
 234         Sg_fd *sfp;
 235         int res;
 236         int retval;
 237
 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 (ppos != &filp->f_pos) ;     /* FIXME: Hmm.  Seek to the right place, or fail?  */
 348         if ((k = verify_area(VERIFY_WRITE, buf, count)))
 349                 return k;
 350         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 351                 if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 352                         return -EFAULT;
 353                 if (old_hdr.reply_len < 0) {
 354                         if (count >= SZ_SG_IO_HDR) {
 355                                 if (__copy_from_user
 356                                     (&new_hdr, buf, SZ_SG_IO_HDR))
 357                                         return -EFAULT;
 358                                 req_pack_id = new_hdr.pack_id;
 359                         }
 360                 } else
 361                         req_pack_id = old_hdr.pack_id;
 362         }
 363         srp = sg_get_rq_mark(sfp, req_pack_id);
 364         if (!srp) {             /* now wait on packet to arrive */
 365                 if (sdp->detached)
 366                         return -ENODEV;
 367                 if (filp->f_flags & O_NONBLOCK)
 368                         return -EAGAIN;
 369                 while (1) {
 370                         res = 0;        /* following is a macro that beats race condition */
 371                         __wait_event_interruptible(sfp->read_wait,
 372                                 (sdp->detached || (srp = sg_get_rq_mark(sfp, req_pack_id))),
 373                                                    res);
 374                         if (sdp->detached)
 375                                 return -ENODEV;
 376                         if (0 == res)
 377                                 break;
 378                         return res;     /* -ERESTARTSYS because signal hit process */
 379                 }
 380         }
 381         if (srp->header.interface_id != '\0')
 382                 return sg_new_read(sfp, buf, count, srp);
 383
 384         hp = &srp->header;
 385         memset(&old_hdr, 0, SZ_SG_HEADER);
 386         old_hdr.reply_len = (int) hp->timeout;
 387         old_hdr.pack_len = old_hdr.reply_len; /* very old, strange behaviour */
 388         old_hdr.pack_id = hp->pack_id;
 389         old_hdr.twelve_byte =
 390             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 391         old_hdr.target_status = hp->masked_status;
 392         old_hdr.host_status = hp->host_status;
 393         old_hdr.driver_status = hp->driver_status;
 394         if ((CHECK_CONDITION & hp->masked_status) ||
 395             (DRIVER_SENSE & hp->driver_status))
 396                 memcpy(old_hdr.sense_buffer, srp->sense_b,
 397                        sizeof (old_hdr.sense_buffer));
 398         switch (hp->host_status) {
 399         /* This setup of 'result' is for backward compatibility and is best
 400            ignored by the user who should use target, host + driver status */
 401         case DID_OK:
 402         case DID_PASSTHROUGH:
 403         case DID_SOFT_ERROR:
 404                 old_hdr.result = 0;
 405                 break;
 406         case DID_NO_CONNECT:
 407         case DID_BUS_BUSY:
 408         case DID_TIME_OUT:
 409                 old_hdr.result = EBUSY;
 410                 break;
 411         case DID_BAD_TARGET:
 412         case DID_ABORT:
 413         case DID_PARITY:
 414         case DID_RESET:
 415         case DID_BAD_INTR:
 416                 old_hdr.result = EIO;
 417                 break;
 418         case DID_ERROR:
 419                 old_hdr.result = (srp->sense_b[0] == 0 &&
 420                                   hp->masked_status == GOOD) ? 0 : EIO;
 421                 break;
 422         default:
 423                 old_hdr.result = EIO;
 424                 break;
 425         }
 426
 427         /* Now copy the result back to the user buffer.  */
 428         if (count >= SZ_SG_HEADER) {
 429                 if (__copy_to_user(buf, &old_hdr, SZ_SG_HEADER))
 430                         return -EFAULT;
 431                 buf += SZ_SG_HEADER;
 432                 if (count > old_hdr.reply_len)
 433                         count = old_hdr.reply_len;
 434                 if (count > SZ_SG_HEADER) {
 435                         if ((res =
 436                              sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)))
 437                                 return -EFAULT;
 438                 }
 439         } else
 440                 count = (old_hdr.result == 0) ? 0 : -EIO;
 441         sg_finish_rem_req(srp);
 442         return count;
 443 }
 444
 445 static ssize_t
 446 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 447 {
 448         sg_io_hdr_t *hp = &srp->header;
 449         int err = 0;
 450         int len;
 451
 452         if (count < SZ_SG_IO_HDR) {
 453                 err = -EINVAL;
 454                 goto err_out;
 455         }
 456         hp->sb_len_wr = 0;
 457         if ((hp->mx_sb_len > 0) && hp->sbp) {
 458                 if ((CHECK_CONDITION & hp->masked_status) ||
 459                     (DRIVER_SENSE & hp->driver_status)) {
 460                         int sb_len = sizeof (dummy_cmdp->sr_sense_buffer);
 461                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 462                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 463                         len = (len > sb_len) ? sb_len : len;
 464                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 465                                 err = -EFAULT;
 466                                 goto err_out;
 467                         }
 468                         hp->sb_len_wr = len;
 469                 }
 470         }
 471         if (hp->masked_status || hp->host_status || hp->driver_status)
 472                 hp->info |= SG_INFO_CHECK;
 473         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 474                 err = -EFAULT;
 475                 goto err_out;
 476         }
 477         err = sg_read_xfer(srp);
 478       err_out:
 479         sg_finish_rem_req(srp);
 480         return (0 == err) ? count : err;
 481 }
 482
 483 static ssize_t
 484 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 485 {
 486         int mxsize, cmd_size, k;
 487         int input_size, blocking;
 488         unsigned char opcode;
 489         Sg_device *sdp;
 490         Sg_fd *sfp;
 491         Sg_request *srp;
 492         struct sg_header old_hdr;
 493         sg_io_hdr_t *hp;
 494         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
 495
 496         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 497                 return -ENXIO;
 498         SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n",
 499                                    sdp->disk->disk_name, (int) count));
 500         if (sdp->detached)
 501                 return -ENODEV;
 502         if (!((filp->f_flags & O_NONBLOCK) ||
 503               scsi_block_when_processing_errors(sdp->device)))
 504                 return -ENXIO;
 505         if (ppos != &filp->f_pos) ;     /* FIXME: Hmm.  Seek to the right place, or fail?  */
 506
 507         if ((k = verify_area(VERIFY_READ, buf, count)))
 508                 return k;       /* protects following copy_from_user()s + get_user()s */
 509         if (count < SZ_SG_HEADER)
 510                 return -EIO;
 511         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 512                 return -EFAULT;
 513         blocking = !(filp->f_flags & O_NONBLOCK);
 514         if (old_hdr.reply_len < 0)
 515                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
 516         if (count < (SZ_SG_HEADER + 6))
 517                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 518
 519         if (!(srp = sg_add_request(sfp))) {
 520                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 521                 return -EDOM;
 522         }
 523         buf += SZ_SG_HEADER;
 524         __get_user(opcode, buf);
 525         if (sfp->next_cmd_len > 0) {
 526                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 527                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 528                         sfp->next_cmd_len = 0;
 529                         sg_remove_request(sfp, srp);
 530                         return -EIO;
 531                 }
 532                 cmd_size = sfp->next_cmd_len;
 533                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 534         } else {
 535                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 536                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 537                         cmd_size = 12;
 538         }
 539         SCSI_LOG_TIMEOUT(4, printk(
 540                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 541 /* Determine buffer size.  */
 542         input_size = count - cmd_size;
 543         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 544         mxsize -= SZ_SG_HEADER;
 545         input_size -= SZ_SG_HEADER;
 546         if (input_size < 0) {
 547                 sg_remove_request(sfp, srp);
 548                 return -EIO;    /* User did not pass enough bytes for this command. */
 549         }
 550         hp = &srp->header;
 551         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 552         hp->cmd_len = (unsigned char) cmd_size;
 553         hp->iovec_count = 0;
 554         hp->mx_sb_len = 0;
 555         if (input_size > 0)
 556                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 557                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 558         else
 559                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 560         hp->dxfer_len = mxsize;
 561         hp->dxferp = (char __user *)buf + cmd_size;
 562         hp->sbp = NULL;
 563         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 564         hp->flags = input_size; /* structure abuse ... */
 565         hp->pack_id = old_hdr.pack_id;
 566         hp->usr_ptr = NULL;
 567         if (__copy_from_user(cmnd, buf, cmd_size))
 568                 return -EFAULT;
 569         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 570         return (k < 0) ? k : count;
 571 }
 572
 573 static ssize_t
 574 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 575              int blocking, int read_only, Sg_request ** o_srp)
 576 {
 577         int k;
 578         Sg_request *srp;
 579         sg_io_hdr_t *hp;
 580         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
 581         int timeout;
 582
 583         if (count < SZ_SG_IO_HDR)
 584                 return -EINVAL;
 585         if ((k = verify_area(VERIFY_READ, buf, count)))
 586                 return k; /* protects following copy_from_user()s + get_user()s */
 587
 588         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 589         if (!(srp = sg_add_request(sfp))) {
 590                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 591                 return -EDOM;
 592         }
 593         hp = &srp->header;
 594         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 595                 sg_remove_request(sfp, srp);
 596                 return -EFAULT;
 597         }
 598         if (hp->interface_id != 'S') {
 599                 sg_remove_request(sfp, srp);
 600                 return -ENOSYS;
 601         }
 602         if (hp->flags & SG_FLAG_MMAP_IO) {
 603                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 604                         sg_remove_request(sfp, srp);
 605                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 606                 }
 607                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 608                         sg_remove_request(sfp, srp);
 609                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 610                 }
 611                 if (sg_res_in_use(sfp)) {
 612                         sg_remove_request(sfp, srp);
 613                         return -EBUSY;  /* reserve buffer already being used */
 614                 }
 615         }
 616         timeout = sg_ms_to_jif(srp->header.timeout);
 617         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 618                 sg_remove_request(sfp, srp);
 619                 return -EMSGSIZE;
 620         }
 621         if ((k = verify_area(VERIFY_READ, hp->cmdp, hp->cmd_len))) {
 622                 sg_remove_request(sfp, srp);
 623                 return k;       /* protects following copy_from_user()s + get_user()s */
 624         }
 625         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 626                 sg_remove_request(sfp, srp);
 627                 return -EFAULT;
 628         }
 629         if (read_only &&
 630             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
 631                 sg_remove_request(sfp, srp);
 632                 return -EPERM;
 633         }
 634         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 635         if (k < 0)
 636                 return k;
 637         if (o_srp)
 638                 *o_srp = srp;
 639         return count;
 640 }
 641
 642 static int
 643 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 644                 unsigned char *cmnd, int timeout, int blocking)
 645 {
 646         int k;
 647         Scsi_Request *SRpnt;
 648         Sg_device *sdp = sfp->parentdp;
 649         sg_io_hdr_t *hp = &srp->header;
 650         request_queue_t *q;
 651
 652         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 653         hp->status = 0;
 654         hp->masked_status = 0;
 655         hp->msg_status = 0;
 656         hp->info = 0;
 657         hp->host_status = 0;
 658         hp->driver_status = 0;
 659         hp->resid = 0;
 660         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 661                           (int) cmnd[0], (int) hp->cmd_len));
 662
 663         if ((k = sg_start_req(srp))) {
 664                 SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
 665                 sg_finish_rem_req(srp);
 666                 return k;       /* probably out of space --> ENOMEM */
 667         }
 668         if ((k = sg_write_xfer(srp))) {
 669                 SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
 670                 sg_finish_rem_req(srp);
 671                 return k;
 672         }
 673         if (sdp->detached) {
 674                 sg_finish_rem_req(srp);
 675                 return -ENODEV;
 676         }
 677         SRpnt = scsi_allocate_request(sdp->device, GFP_ATOMIC);
 678         if (SRpnt == NULL) {
 679                 SCSI_LOG_TIMEOUT(1, printk("sg_write: no mem\n"));
 680                 sg_finish_rem_req(srp);
 681                 return -ENOMEM;
 682         }
 683
 684         srp->my_cmdp = SRpnt;
 685         q = SRpnt->sr_device->request_queue;
 686         SRpnt->sr_request->rq_disk = sdp->disk;
 687         SRpnt->sr_sense_buffer[0] = 0;
 688         SRpnt->sr_cmd_len = hp->cmd_len;
 689         SRpnt->sr_use_sg = srp->data.k_use_sg;
 690         SRpnt->sr_sglist_len = srp->data.sglist_len;
 691         SRpnt->sr_bufflen = srp->data.bufflen;
 692         SRpnt->sr_underflow = 0;
 693         SRpnt->sr_buffer = srp->data.buffer;
 694         switch (hp->dxfer_direction) {
 695         case SG_DXFER_TO_FROM_DEV:
 696         case SG_DXFER_FROM_DEV:
 697                 SRpnt->sr_data_direction = SCSI_DATA_READ;
 698                 break;
 699         case SG_DXFER_TO_DEV:
 700                 SRpnt->sr_data_direction = SCSI_DATA_WRITE;
 701                 break;
 702         case SG_DXFER_UNKNOWN:
 703                 SRpnt->sr_data_direction = SCSI_DATA_UNKNOWN;
 704                 break;
 705         default:
 706                 SRpnt->sr_data_direction = SCSI_DATA_NONE;
 707                 break;
 708         }
 709         SRpnt->upper_private_data = srp;
 710         srp->data.k_use_sg = 0;
 711         srp->data.sglist_len = 0;
 712         srp->data.bufflen = 0;
 713         srp->data.buffer = NULL;
 714         hp->duration = jiffies; /* unit jiffies now, millisecs after done */
 715 /* Now send everything of to mid-level. The next time we hear about this
 716    packet is when sg_cmd_done() is called (i.e. a callback). */
 717         scsi_do_req(SRpnt, (void *) cmnd,
 718                     (void *) SRpnt->sr_buffer, hp->dxfer_len,
 719                     sg_cmd_done, timeout, SG_DEFAULT_RETRIES);
 720         /* dxfer_len overwrites SRpnt->sr_bufflen, hence need for b_malloc_len */
 721         generic_unplug_device(q);
 722         return 0;
 723 }
 724
 725 static int
 726 sg_ioctl(struct inode *inode, struct file *filp,
 727          unsigned int cmd_in, unsigned long arg)
 728 {
 729         void __user *p = (void __user *)arg;
 730         int __user *ip = p;
 731         int result, val, read_only;
 732         Sg_device *sdp;
 733         Sg_fd *sfp;
 734         Sg_request *srp;
 735         unsigned long iflags;
 736
 737         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 738                 return -ENXIO;
 739         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 740                                    sdp->disk->disk_name, (int) cmd_in));
 741         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 742
 743         switch (cmd_in) {
 744         case SG_IO:
 745                 {
 746                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 747
 748                         if (sdp->detached)
 749                                 return -ENODEV;
 750                         if (!scsi_block_when_processing_errors(sdp->device))
 751                                 return -ENXIO;
 752                         result = verify_area(VERIFY_WRITE, p, SZ_SG_IO_HDR);
 753                         if (result)
 754                                 return result;
 755                         result =
 756                             sg_new_write(sfp, p, SZ_SG_IO_HDR,
 757                                          blocking, read_only, &srp);
 758                         if (result < 0)
 759                                 return result;
 760                         srp->sg_io_owned = 1;
 761                         while (1) {
 762                                 result = 0;     /* following macro to beat race condition */
 763                                 __wait_event_interruptible(sfp->read_wait,
 764                                         (sdp->detached || sfp->closed || srp->done),
 765                                                            result);
 766                                 if (sdp->detached)
 767                                         return -ENODEV;
 768                                 if (sfp->closed)
 769                                         return 0;       /* request packet dropped already */
 770                                 if (0 == result)
 771                                         break;
 772                                 srp->orphan = 1;
 773                                 return result;  /* -ERESTARTSYS because signal hit process */
 774                         }
 775                         srp->done = 2;
 776                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 777                         return (result < 0) ? result : 0;
 778                 }
 779         case SG_SET_TIMEOUT:
 780                 result = get_user(val, ip);
 781                 if (result)
 782                         return result;
 783                 if (val < 0)
 784                         return -EIO;
 785                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 786                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 787                 sfp->timeout_user = val;
 788                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 789
 790                 return 0;
 791         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 792                                 /* strange ..., for backward compatibility */
 793                 return sfp->timeout_user;
 794         case SG_SET_FORCE_LOW_DMA:
 795                 result = get_user(val, ip);
 796                 if (result)
 797                         return result;
 798                 if (val) {
 799                         sfp->low_dma = 1;
 800                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 801                                 val = (int) sfp->reserve.bufflen;
 802                                 sg_remove_scat(&sfp->reserve);
 803                                 sg_build_reserve(sfp, val);
 804                         }
 805                 } else {
 806                         if (sdp->detached)
 807                                 return -ENODEV;
 808                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 809                 }
 810                 return 0;
 811         case SG_GET_LOW_DMA:
 812                 return put_user((int) sfp->low_dma, ip);
 813         case SG_GET_SCSI_ID:
 814                 result =
 815                     verify_area(VERIFY_WRITE, p, sizeof (sg_scsi_id_t));
 816                 if (result)
 817                         return result;
 818                 else {
 819                         sg_scsi_id_t __user *sg_idp = p;
 820
 821                         if (sdp->detached)
 822                                 return -ENODEV;
 823                         __put_user((int) sdp->device->host->host_no,
 824                                    &sg_idp->host_no);
 825                         __put_user((int) sdp->device->channel,
 826                                    &sg_idp->channel);
 827                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 828                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 829                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 830                         __put_user((short) sdp->device->host->cmd_per_lun,
 831                                    &sg_idp->h_cmd_per_lun);
 832                         __put_user((short) sdp->device->queue_depth,
 833                                    &sg_idp->d_queue_depth);
 834                         __put_user(0, &sg_idp->unused[0]);
 835                         __put_user(0, &sg_idp->unused[1]);
 836                         return 0;
 837                 }
 838         case SG_SET_FORCE_PACK_ID:
 839                 result = get_user(val, ip);
 840                 if (result)
 841                         return result;
 842                 sfp->force_packid = val ? 1 : 0;
 843                 return 0;
 844         case SG_GET_PACK_ID:
 845                 result = verify_area(VERIFY_WRITE, ip, sizeof (int));
 846                 if (result)
 847                         return result;
 848                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 849                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 850                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 851                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 852                                                        iflags);
 853                                 __put_user(srp->header.pack_id, ip);
 854                                 return 0;
 855                         }
 856                 }
 857                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 858                 __put_user(-1, ip);
 859                 return 0;
 860         case SG_GET_NUM_WAITING:
 861                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 862                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 863                         if ((1 == srp->done) && (!srp->sg_io_owned))
 864                                 ++val;
 865                 }
 866                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 867                 return put_user(val, ip);
 868         case SG_GET_SG_TABLESIZE:
 869                 return put_user(sdp->sg_tablesize, ip);
 870         case SG_SET_RESERVED_SIZE:
 871                 result = get_user(val, ip);
 872                 if (result)
 873                         return result;
 874                 if (val < 0)
 875                         return -EINVAL;
 876                 if (val != sfp->reserve.bufflen) {
 877                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 878                                 return -EBUSY;
 879                         sg_remove_scat(&sfp->reserve);
 880                         sg_build_reserve(sfp, val);
 881                 }
 882                 return 0;
 883         case SG_GET_RESERVED_SIZE:
 884                 val = (int) sfp->reserve.bufflen;
 885                 return put_user(val, ip);
 886         case SG_SET_COMMAND_Q:
 887                 result = get_user(val, ip);
 888                 if (result)
 889                         return result;
 890                 sfp->cmd_q = val ? 1 : 0;
 891                 return 0;
 892         case SG_GET_COMMAND_Q:
 893                 return put_user((int) sfp->cmd_q, ip);
 894         case SG_SET_KEEP_ORPHAN:
 895                 result = get_user(val, ip);
 896                 if (result)
 897                         return result;
 898                 sfp->keep_orphan = val;
 899                 return 0;
 900         case SG_GET_KEEP_ORPHAN:
 901                 return put_user((int) sfp->keep_orphan, ip);
 902         case SG_NEXT_CMD_LEN:
 903                 result = get_user(val, ip);
 904                 if (result)
 905                         return result;
 906                 sfp->next_cmd_len = (val > 0) ? val : 0;
 907                 return 0;
 908         case SG_GET_VERSION_NUM:
 909                 return put_user(sg_version_num, ip);
 910         case SG_GET_ACCESS_COUNT:
 911                 /* faked - we don't have a real access count anymore */
 912                 val = (sdp->device ? 1 : 0);
 913                 return put_user(val, ip);
 914         case SG_GET_REQUEST_TABLE:
 915                 result = verify_area(VERIFY_WRITE, p,
 916                                      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
 917                 if (result)
 918                         return result;
 919                 else {
 920                         sg_req_info_t rinfo[SG_MAX_QUEUE];
 921                         Sg_request *srp;
 922                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 923                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 924                              ++val, srp = srp ? srp->nextrp : srp) {
 925                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 926                                 if (srp) {
 927                                         rinfo[val].req_state = srp->done + 1;
 928                                         rinfo[val].problem =
 929                                             srp->header.masked_status &
 930                                             srp->header.host_status &
 931                                             srp->header.driver_status;
 932                                         rinfo[val].duration =
 933                                             srp->done ? srp->header.duration :
 934                                             sg_jif_to_ms(
 935                                                 jiffies - srp->header.duration);
 936                                         rinfo[val].orphan = srp->orphan;
 937                                         rinfo[val].sg_io_owned = srp->sg_io_owned;
 938                                         rinfo[val].pack_id = srp->header.pack_id;
 939                                         rinfo[val].usr_ptr = srp->header.usr_ptr;
 940                                 }
 941                         }
 942                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 943                         return (__copy_to_user(p, rinfo,
 944                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE) ? -EFAULT : 0);
 945                 }
 946         case SG_EMULATED_HOST:
 947                 if (sdp->detached)
 948                         return -ENODEV;
 949                 return put_user(sdp->device->host->hostt->emulated, ip);
 950         case SG_SCSI_RESET:
 951                 if (sdp->detached)
 952                         return -ENODEV;
 953                 if (filp->f_flags & O_NONBLOCK) {
 954                         if (test_bit(SHOST_RECOVERY,
 955                                      &sdp->device->host->shost_state))
 956                                 return -EBUSY;
 957                 } else if (!scsi_block_when_processing_errors(sdp->device))
 958                         return -EBUSY;
 959                 result = get_user(val, ip);
 960                 if (result)
 961                         return result;
 962                 if (SG_SCSI_RESET_NOTHING == val)
 963                         return 0;
 964                 switch (val) {
 965                 case SG_SCSI_RESET_DEVICE:
 966                         val = SCSI_TRY_RESET_DEVICE;
 967                         break;
 968                 case SG_SCSI_RESET_BUS:
 969                         val = SCSI_TRY_RESET_BUS;
 970                         break;
 971                 case SG_SCSI_RESET_HOST:
 972                         val = SCSI_TRY_RESET_HOST;
 973                         break;
 974                 default:
 975                         return -EINVAL;
 976                 }
 977                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 978                         return -EACCES;
 979                 return (scsi_reset_provider(sdp->device, val) ==
 980                         SUCCESS) ? 0 : -EIO;
 981         case SCSI_IOCTL_SEND_COMMAND:
 982                 if (sdp->detached)
 983                         return -ENODEV;
 984                 if (read_only) {
 985                         unsigned char opcode = WRITE_6;
 986                         Scsi_Ioctl_Command __user *siocp = p;
 987
 988                         if (copy_from_user(&opcode, siocp->data, 1))
 989                                 return -EFAULT;
 990                         if (!sg_allow_access(opcode, sdp->device->type))
 991                                 return -EPERM;
 992                 }
 993                 return scsi_ioctl_send_command(sdp->device, p);
 994         case SG_SET_DEBUG:
 995                 result = get_user(val, ip);
 996                 if (result)
 997                         return result;
 998                 sdp->sgdebug = (char) val;
 999                 return 0;
1000         case SCSI_IOCTL_GET_IDLUN:
1001         case SCSI_IOCTL_GET_BUS_NUMBER:
1002         case SCSI_IOCTL_PROBE_HOST:
1003         case SG_GET_TRANSFORM:
1004                 if (sdp->detached)
1005                         return -ENODEV;
1006                 return scsi_ioctl(sdp->device, cmd_in, p);
1007         default:
1008                 if (read_only)
1009                         return -EPERM;  /* don't know so take safe approach */
1010                 return scsi_ioctl(sdp->device, cmd_in, p);
1011         }
1012 }
1013
1014 static unsigned int
1015 sg_poll(struct file *filp, poll_table * wait)
1016 {
1017         unsigned int res = 0;
1018         Sg_device *sdp;
1019         Sg_fd *sfp;
1020         Sg_request *srp;
1021         int count = 0;
1022         unsigned long iflags;
1023
1024         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1025             || sfp->closed)
1026                 return POLLERR;
1027         poll_wait(filp, &sfp->read_wait, wait);
1028         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1029         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1030                 /* if any read waiting, flag it */
1031                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1032                         res = POLLIN | POLLRDNORM;
1033                 ++count;
1034         }
1035         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1036
1037         if (sdp->detached)
1038                 res |= POLLHUP;
1039         else if (!sfp->cmd_q) {
1040                 if (0 == count)
1041                         res |= POLLOUT | POLLWRNORM;
1042         } else if (count < SG_MAX_QUEUE)
1043                 res |= POLLOUT | POLLWRNORM;
1044         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1045                                    sdp->disk->disk_name, (int) res));
1046         return res;
1047 }
1048
1049 static int
1050 sg_fasync(int fd, struct file *filp, int mode)
1051 {
1052         int retval;
1053         Sg_device *sdp;
1054         Sg_fd *sfp;
1055
1056         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1057                 return -ENXIO;
1058         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1059                                    sdp->disk->disk_name, mode));
1060
1061         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1062         return (retval < 0) ? retval : 0;
1063 }
1064
1065 static inline unsigned char *
1066 sg_scatg2virt(const struct scatterlist *sclp)
1067 {
1068         return (sclp && sclp->page) ?
1069             (unsigned char *) page_address(sclp->page) + sclp->offset : NULL;
1070 }
1071
1072 /* When startFinish==1 increments page counts for pages other than the
1073    first of scatter gather elements obtained from __get_free_pages().
1074    When startFinish==0 decrements ... */
1075 static void
1076 sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
1077 {
1078         void *page_ptr;
1079         struct page *page;
1080         int k, m;
1081
1082         SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n",
1083                                    startFinish, rsv_schp->k_use_sg));
1084         /* N.B. correction _not_ applied to base page of each allocation */
1085         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1086                 struct scatterlist *sclp = rsv_schp->buffer;
1087
1088                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
1089                         for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
1090                                 page_ptr = sg_scatg2virt(sclp) + m;
1091                                 page = virt_to_page(page_ptr);
1092                                 if (startFinish)
1093                                         get_page(page);
1094                                 else {
1095                                         if (page_count(page) > 0)
1096                                                 __put_page(page);
1097                                 }
1098                         }
1099                 }
1100         } else {                /* reserve buffer is just a single allocation */
1101                 for (m = PAGE_SIZE; m < rsv_schp->bufflen; m += PAGE_SIZE) {
1102                         page_ptr = (unsigned char *) rsv_schp->buffer + m;
1103                         page = virt_to_page(page_ptr);
1104                         if (startFinish)
1105                                 get_page(page);
1106                         else {
1107                                 if (page_count(page) > 0)
1108                                         __put_page(page);
1109                         }
1110                 }
1111         }
1112 }
1113
1114 static struct page *
1115 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1116 {
1117         Sg_fd *sfp;
1118         struct page *page = NOPAGE_SIGBUS;
1119         void *page_ptr = NULL;
1120         unsigned long offset;
1121         Sg_scatter_hold *rsv_schp;
1122
1123         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1124                 return page;
1125         rsv_schp = &sfp->reserve;
1126         offset = addr - vma->vm_start;
1127         if (offset >= rsv_schp->bufflen)
1128                 return page;
1129         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1130                                    offset, rsv_schp->k_use_sg));
1131         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1132                 int k;
1133                 unsigned long sa = vma->vm_start;
1134                 unsigned long len;
1135                 struct scatterlist *sclp = rsv_schp->buffer;
1136
1137                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1138                      ++k, ++sclp) {
1139                         len = vma->vm_end - sa;
1140                         len = (len < sclp->length) ? len : sclp->length;
1141                         if (offset < len) {
1142                                 page_ptr = sg_scatg2virt(sclp) + offset;
1143                                 page = virt_to_page(page_ptr);
1144                                 get_page(page); /* increment page count */
1145                                 break;
1146                         }
1147                         sa += len;
1148                         offset -= len;
1149                 }
1150         } else {                /* reserve buffer is just a single allocation */
1151                 page_ptr = (unsigned char *) rsv_schp->buffer + offset;
1152                 page = virt_to_page(page_ptr);
1153                 get_page(page); /* increment page count */
1154         }
1155         if (type)
1156                 *type = VM_FAULT_MINOR;
1157         return page;
1158 }
1159
1160 static struct vm_operations_struct sg_mmap_vm_ops = {
1161         .nopage = sg_vma_nopage,
1162 };
1163
1164 static int
1165 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1166 {
1167         Sg_fd *sfp;
1168         unsigned long req_sz = vma->vm_end - vma->vm_start;
1169         Sg_scatter_hold *rsv_schp;
1170
1171         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1172                 return -ENXIO;
1173         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1174                                    (void *) vma->vm_start, (int) req_sz));
1175         if (vma->vm_pgoff)
1176                 return -EINVAL; /* want no offset */
1177         rsv_schp = &sfp->reserve;
1178         if (req_sz > rsv_schp->bufflen)
1179                 return -ENOMEM; /* cannot map more than reserved buffer */
1180
1181         if (rsv_schp->k_use_sg) { /* reserve buffer is a scatter gather list */
1182                 int k;
1183                 unsigned long sa = vma->vm_start;
1184                 unsigned long len;
1185                 struct scatterlist *sclp = rsv_schp->buffer;
1186
1187                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1188                      ++k, ++sclp) {
1189                         if (0 != sclp->offset)
1190                                 return -EFAULT; /* non page aligned memory ?? */
1191                         len = vma->vm_end - sa;
1192                         len = (len < sclp->length) ? len : sclp->length;
1193                         sa += len;
1194                 }
1195         } else {        /* reserve buffer is just a single allocation */
1196                 if ((unsigned long) rsv_schp->buffer & (PAGE_SIZE - 1))
1197                         return -EFAULT; /* non page aligned memory ?? */
1198         }
1199         if (0 == sfp->mmap_called) {
1200                 sg_rb_correct4mmap(rsv_schp, 1);        /* do only once per fd lifetime */
1201                 sfp->mmap_called = 1;
1202         }
1203         vma->vm_flags |= (VM_RESERVED | VM_IO);
1204         vma->vm_private_data = sfp;
1205         vma->vm_ops = &sg_mmap_vm_ops;
1206         return 0;
1207 }
1208
1209 /* This function is a "bottom half" handler that is called by the
1210  * mid level when a command is completed (or has failed). */
1211 static void
1212 sg_cmd_done(Scsi_Cmnd * SCpnt)
1213 {
1214         Scsi_Request *SRpnt = NULL;
1215         Sg_device *sdp = NULL;
1216         Sg_fd *sfp;
1217         Sg_request *srp = NULL;
1218
1219         if (SCpnt && (SRpnt = SCpnt->sc_request))
1220                 srp = (Sg_request *) SRpnt->upper_private_data;
1221         if (NULL == srp) {
1222                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1223                 if (SRpnt)
1224                         scsi_release_request(SRpnt);
1225                 return;
1226         }
1227         sfp = srp->parentfp;
1228         if (sfp)
1229                 sdp = sfp->parentdp;
1230         if ((NULL == sdp) || sdp->detached) {
1231                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1232                 scsi_release_request(SRpnt);
1233                 return;
1234         }
1235
1236         /* First transfer ownership of data buffers to sg_device object. */
1237         srp->data.k_use_sg = SRpnt->sr_use_sg;
1238         srp->data.sglist_len = SRpnt->sr_sglist_len;
1239         srp->data.bufflen = SRpnt->sr_bufflen;
1240         srp->data.buffer = SRpnt->sr_buffer;
1241         /* now clear out request structure */
1242         SRpnt->sr_use_sg = 0;
1243         SRpnt->sr_sglist_len = 0;
1244         SRpnt->sr_bufflen = 0;
1245         SRpnt->sr_buffer = NULL;
1246         SRpnt->sr_underflow = 0;
1247         SRpnt->sr_request->rq_disk = NULL; /* "sg" _disowns_ request blk */
1248
1249         srp->my_cmdp = NULL;
1250
1251         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1252                 sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
1253         srp->header.resid = SCpnt->resid;
1254         /* N.B. unit of duration changes here from jiffies to millisecs */
1255         srp->header.duration =
1256             sg_jif_to_ms(jiffies - (int) srp->header.duration);
1257         if (0 != SRpnt->sr_result) {
1258                 memcpy(srp->sense_b, SRpnt->sr_sense_buffer,
1259                        sizeof (srp->sense_b));
1260                 srp->header.status = 0xff & SRpnt->sr_result;
1261                 srp->header.masked_status = status_byte(SRpnt->sr_result);
1262                 srp->header.msg_status = msg_byte(SRpnt->sr_result);
1263                 srp->header.host_status = host_byte(SRpnt->sr_result);
1264                 srp->header.driver_status = driver_byte(SRpnt->sr_result);
1265                 if ((sdp->sgdebug > 0) &&
1266                     ((CHECK_CONDITION == srp->header.masked_status) ||
1267                      (COMMAND_TERMINATED == srp->header.masked_status)))
1268                         print_req_sense("sg_cmd_done", SRpnt);
1269
1270                 /* Following if statement is a patch supplied by Eric Youngdale */
1271                 if (driver_byte(SRpnt->sr_result) != 0
1272                     && (SRpnt->sr_sense_buffer[0] & 0x7f) == 0x70
1273                     && (SRpnt->sr_sense_buffer[2] & 0xf) == UNIT_ATTENTION
1274                     && sdp->device->removable) {
1275                         /* Detected disc change. Set the bit - this may be used if */
1276                         /* there are filesystems using this device. */
1277                         sdp->device->changed = 1;
1278                 }
1279         }
1280         /* Rely on write phase to clean out srp status values, so no "else" */
1281
1282         scsi_release_request(SRpnt);
1283         SRpnt = NULL;
1284         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1285                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1286                 sg_finish_rem_req(srp);
1287                 srp = NULL;
1288                 if (NULL == sfp->headrp) {
1289                         SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1290                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1291                                 scsi_device_put(sdp->device);
1292                         }
1293                         sfp = NULL;
1294                 }
1295         } else if (srp && srp->orphan) {
1296                 if (sfp->keep_orphan)
1297                         srp->sg_io_owned = 0;
1298                 else {
1299                         sg_finish_rem_req(srp);
1300                         srp = NULL;
1301                 }
1302         }
1303         if (sfp && srp) {
1304                 /* Now wake up any sg_read() that is waiting for this packet. */
1305                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1306                 srp->done = 1;
1307                 wake_up_interruptible(&sfp->read_wait);
1308         }
1309 }
1310
1311 static struct file_operations sg_fops = {
1312         .owner = THIS_MODULE,
1313         .read = sg_read,
1314         .write = sg_write,
1315         .poll = sg_poll,
1316         .ioctl = sg_ioctl,
1317         .open = sg_open,
1318         .mmap = sg_mmap,
1319         .release = sg_release,
1320         .fasync = sg_fasync,
1321 };
1322
1323 static struct class_simple * sg_sysfs_class;
1324
1325 static int sg_sysfs_valid = 0;
1326
1327 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1328 {
1329         Sg_device *sdp;
1330         unsigned long iflags;
1331         void *old_sg_dev_arr = NULL;
1332         int k, error;
1333
1334         sdp = vmalloc(sizeof(Sg_device));
1335         if (!sdp)
1336                 return -ENOMEM;
1337
1338         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1339         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1340                 Sg_device **tmp_da;
1341                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1342                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1343
1344                 tmp_da = vmalloc(tmp_dev_max * sizeof(Sg_device *));
1345                 if (unlikely(!tmp_da))
1346                         goto expand_failed;
1347
1348                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1349                 memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
1350                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1351                 old_sg_dev_arr = sg_dev_arr;
1352                 sg_dev_arr = tmp_da;
1353                 sg_dev_max = tmp_dev_max;
1354         }
1355
1356         for (k = 0; k < sg_dev_max; k++)
1357                 if (!sg_dev_arr[k])
1358                         break;
1359         if (unlikely(k >= SG_MAX_DEVS))
1360                 goto overflow;
1361
1362         memset(sdp, 0, sizeof(*sdp));
1363         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1364         sprintf(disk->disk_name, "sg%d", k);
1365         disk->first_minor = k;
1366         sdp->disk = disk;
1367         sdp->device = scsidp;
1368         init_waitqueue_head(&sdp->o_excl_wait);
1369         sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
1370
1371         sg_nr_dev++;
1372         sg_dev_arr[k] = sdp;
1373         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1374         error = k;
1375
1376  out:
1377         if (error < 0)
1378                 vfree(sdp);
1379         vfree(old_sg_dev_arr);
1380         return error;
1381
1382  expand_failed:
1383         printk(KERN_ERR "sg_alloc: device array cannot be resized\n");
1384         error = -ENOMEM;
1385         goto out;
1386
1387  overflow:
1388         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1389         printk(KERN_WARNING
1390                "Unable to attach sg device <%d, %d, %d, %d> type=%d, minor "
1391                "number exceeds %d\n", scsidp->host->host_no, scsidp->channel,
1392                scsidp->id, scsidp->lun, scsidp->type, SG_MAX_DEVS - 1);
1393         error = -ENODEV;
1394         goto out;
1395 }
1396
1397 static int
1398 sg_add(struct class_device *cl_dev)
1399 {
1400         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1401         struct gendisk *disk;
1402         Sg_device *sdp = NULL;
1403         struct cdev * cdev = NULL;
1404         int error, k;
1405
1406         disk = alloc_disk(1);
1407         if (!disk)
1408                 return -ENOMEM;
1409         disk->major = SCSI_GENERIC_MAJOR;
1410
1411         error = -ENOMEM;
1412         cdev = cdev_alloc();
1413         if (!cdev)
1414                 goto out;
1415         cdev->owner = THIS_MODULE;
1416         cdev->ops = &sg_fops;
1417
1418         error = sg_alloc(disk, scsidp);
1419         if (error < 0)
1420                 goto out;
1421         k = error;
1422         sdp = sg_dev_arr[k];
1423
1424         devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
1425                         S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
1426                         "%s/generic", scsidp->devfs_name);
1427         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1428         if (error) {
1429                 devfs_remove("%s/generic", scsidp->devfs_name);
1430                 goto out;
1431         }
1432         sdp->cdev = cdev;
1433         if (sg_sysfs_valid) {
1434                 struct class_device * sg_class_member;
1435
1436                 sg_class_member = class_simple_device_add(sg_sysfs_class,
1437                                 MKDEV(SCSI_GENERIC_MAJOR, k),
1438                                 cl_dev->dev, "%s",
1439                                 disk->disk_name);
1440                 if (IS_ERR(sg_class_member))
1441                         printk(KERN_WARNING "sg_add: "
1442                                 "class_simple_device_add failed\n");
1443                 class_set_devdata(sg_class_member, sdp);
1444                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1445                                           &sg_class_member->kobj, "generic");
1446                 if (error)
1447                         printk(KERN_ERR "sg_add: unable to make symlink "
1448                                         "'generic' back to sg%d\n", k);
1449         } else
1450                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1451
1452         printk(KERN_NOTICE
1453                "Attached scsi generic sg%d at scsi%d, channel"
1454                " %d, id %d, lun %d,  type %d\n", k,
1455                scsidp->host->host_no, scsidp->channel, scsidp->id,
1456                scsidp->lun, scsidp->type);
1457
1458         return 0;
1459
1460 out:
1461         put_disk(disk);
1462         if (cdev)
1463                 cdev_del(cdev);
1464         return error;
1465 }
1466
1467 static void
1468 sg_remove(struct class_device *cl_dev)
1469 {
1470         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1471         Sg_device *sdp = NULL;
1472         unsigned long iflags;
1473         Sg_fd *sfp;
1474         Sg_fd *tsfp;
1475         Sg_request *srp;
1476         Sg_request *tsrp;
1477         int k, delay;
1478
1479         if (NULL == sg_dev_arr)
1480                 return;
1481         delay = 0;
1482         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1483         for (k = 0; k < sg_dev_max; k++) {
1484                 sdp = sg_dev_arr[k];
1485                 if ((NULL == sdp) || (sdp->device != scsidp))
1486                         continue;       /* dirty but lowers nesting */
1487                 if (sdp->headfp) {
1488                         sdp->detached = 1;
1489                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1490                                 tsfp = sfp->nextfp;
1491                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1492                                         tsrp = srp->nextrp;
1493                                         if (sfp->closed || (0 == srp->done))
1494                                                 sg_finish_rem_req(srp);
1495                                 }
1496                                 if (sfp->closed) {
1497                                         scsi_device_put(sdp->device);
1498                                         __sg_remove_sfp(sdp, sfp);
1499                                 } else {
1500                                         delay = 1;
1501                                         wake_up_interruptible(&sfp->read_wait);
1502                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1503                                                     POLL_HUP);
1504                                 }
1505                         }
1506                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1507                         if (NULL == sdp->headfp) {
1508                                 sg_dev_arr[k] = NULL;
1509                         }
1510                 } else {        /* nothing active, simple case */
1511                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1512                         sg_dev_arr[k] = NULL;
1513                 }
1514                 sg_nr_dev--;
1515                 break;
1516         }
1517         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1518
1519         if (sdp) {
1520                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1521                 class_simple_device_remove(MKDEV(SCSI_GENERIC_MAJOR, k));
1522                 cdev_del(sdp->cdev);
1523                 sdp->cdev = NULL;
1524                 devfs_remove("%s/generic", scsidp->devfs_name);
1525                 put_disk(sdp->disk);
1526                 sdp->disk = NULL;
1527                 if (NULL == sdp->headfp)
1528                         vfree((char *) sdp);
1529         }
1530
1531         if (delay)
1532                 scsi_sleep(2);  /* dirty detach so delay device destruction */
1533 }
1534
1535 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1536  * of sysfs parameters (which module_param doesn't yet support).
1537  * Sysfs parameters defined explicitly below.
1538  */
1539 module_param_named(def_reserved_size, def_reserved_size, int, 0);
1540 module_param_named(allow_dio, sg_allow_dio, int, 0);
1541
1542 MODULE_AUTHOR("Douglas Gilbert");
1543 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1544 MODULE_LICENSE("GPL");
1545 MODULE_VERSION(SG_VERSION_STR);
1546
1547 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1548 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1549
1550 static int __init
1551 init_sg(void)
1552 {
1553         int rc;
1554
1555         if (def_reserved_size >= 0)
1556                 sg_big_buff = def_reserved_size;
1557
1558         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1559                                     SG_MAX_DEVS, "sg");
1560         if (rc)
1561                 return rc;
1562         sg_sysfs_class = class_simple_create(THIS_MODULE, "scsi_generic");
1563         if ( IS_ERR(sg_sysfs_class) ) {
1564                 rc = PTR_ERR(sg_sysfs_class);
1565                 goto err_out;
1566         }
1567         sg_sysfs_valid = 1;
1568         rc = scsi_register_interface(&sg_interface);
1569         if (0 == rc) {
1570 #ifdef CONFIG_SCSI_PROC_FS
1571                 sg_proc_init();
1572 #endif                          /* CONFIG_SCSI_PROC_FS */
1573                 return 0;
1574         }
1575         class_simple_destroy(sg_sysfs_class);
1576 err_out:
1577         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1578         return rc;
1579 }
1580
1581 static void __exit
1582 exit_sg(void)
1583 {
1584 #ifdef CONFIG_SCSI_PROC_FS
1585         sg_proc_cleanup();
1586 #endif                          /* CONFIG_SCSI_PROC_FS */
1587         scsi_unregister_interface(&sg_interface);
1588         class_simple_destroy(sg_sysfs_class);
1589         sg_sysfs_valid = 0;
1590         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1591                                  SG_MAX_DEVS);
1592         if (sg_dev_arr != NULL) {
1593                 vfree((char *) sg_dev_arr);
1594                 sg_dev_arr = NULL;
1595         }
1596         sg_dev_max = 0;
1597 }
1598
1599 static int
1600 sg_start_req(Sg_request * srp)
1601 {
1602         int res;
1603         Sg_fd *sfp = srp->parentfp;
1604         sg_io_hdr_t *hp = &srp->header;
1605         int dxfer_len = (int) hp->dxfer_len;
1606         int dxfer_dir = hp->dxfer_direction;
1607         Sg_scatter_hold *req_schp = &srp->data;
1608         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1609
1610         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1611         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1612                 return 0;
1613         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1614             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1615             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1616                 res = sg_build_direct(srp, sfp, dxfer_len);
1617                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1618                         return res;
1619         }
1620         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1621                 sg_link_reserve(sfp, srp, dxfer_len);
1622         else {
1623                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1624                 if (res) {
1625                         sg_remove_scat(req_schp);
1626                         return res;
1627                 }
1628         }
1629         return 0;
1630 }
1631
1632 static void
1633 sg_finish_rem_req(Sg_request * srp)
1634 {
1635         Sg_fd *sfp = srp->parentfp;
1636         Sg_scatter_hold *req_schp = &srp->data;
1637
1638         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1639         if (srp->res_used)
1640                 sg_unlink_reserve(sfp, srp);
1641         else
1642                 sg_remove_scat(req_schp);
1643         sg_remove_request(sfp, srp);
1644 }
1645
1646 static int
1647 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1648 {
1649         int ret_sz;
1650         int elem_sz = sizeof (struct scatterlist);
1651         int sg_bufflen = tablesize * elem_sz;
1652         int mx_sc_elems = tablesize;
1653
1654         schp->buffer = sg_page_malloc(sg_bufflen, sfp->low_dma, &ret_sz);
1655         if (!schp->buffer)
1656                 return -ENOMEM;
1657         else if (ret_sz != sg_bufflen) {
1658                 sg_bufflen = ret_sz;
1659                 mx_sc_elems = sg_bufflen / elem_sz;
1660         }
1661         schp->sglist_len = sg_bufflen;
1662         memset(schp->buffer, 0, sg_bufflen);
1663         return mx_sc_elems;     /* number of scat_gath elements allocated */
1664 }
1665
1666 #ifdef SG_ALLOW_DIO_CODE
1667 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1668         /* hopefully this generic code will moved to a library */
1669
1670 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1671    - mapping of all pages not successful
1672    - any page is above max_pfn
1673    (i.e., either completely successful or fails)
1674 */
1675 static int
1676 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1677                   unsigned long uaddr, size_t count, int rw,
1678                   unsigned long max_pfn)
1679 {
1680         int res, i, j;
1681         unsigned int nr_pages;
1682         struct page **pages;
1683
1684         nr_pages = ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT;
1685
1686         /* User attempted Overflow! */
1687         if ((uaddr + count) < uaddr)
1688                 return -EINVAL;
1689
1690         /* Too big */
1691         if (nr_pages > max_pages)
1692                 return -ENOMEM;
1693
1694         /* Hmm? */
1695         if (count == 0)
1696                 return 0;
1697
1698         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1699                 return -ENOMEM;
1700
1701         /* Try to fault in all of the necessary pages */
1702         down_read(&current->mm->mmap_sem);
1703         /* rw==READ means read from drive, write into memory area */
1704         res = get_user_pages(
1705                 current,
1706                 current->mm,
1707                 uaddr,
1708                 nr_pages,
1709                 rw == READ,
1710                 0, /* don't force */
1711                 pages,
1712                 NULL);
1713         up_read(&current->mm->mmap_sem);
1714
1715         /* Errors and no page mapped should return here */
1716         if (res < nr_pages)
1717                 goto out_unmap;
1718
1719         for (i=0; i < nr_pages; i++) {
1720                 /* FIXME: flush superflous for rw==READ,
1721                  * probably wrong function for rw==WRITE
1722                  */
1723                 flush_dcache_page(pages[i]);
1724                 if (page_to_pfn(pages[i]) > max_pfn)
1725                         goto out_unlock;
1726                 /* ?? Is locking needed? I don't think so */
1727                 /* if (TestSetPageLocked(pages[i]))
1728                    goto out_unlock; */
1729         }
1730
1731         /* Populate the scatter/gather list */
1732         sgl[0].page = pages[0];
1733         sgl[0].offset = uaddr & ~PAGE_MASK;
1734         if (nr_pages > 1) {
1735                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1736                 count -= sgl[0].length;
1737                 for (i=1; i < nr_pages ; i++) {
1738                         sgl[i].offset = 0;
1739                         sgl[i].page = pages[i];
1740                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1741                         count -= PAGE_SIZE;
1742                 }
1743         }
1744         else {
1745                 sgl[0].length = count;
1746         }
1747
1748         kfree(pages);
1749         return nr_pages;
1750
1751  out_unlock:
1752         /* for (j=0; j < i; j++)
1753            unlock_page(pages[j]); */
1754         res = 0;
1755  out_unmap:
1756         if (res > 0)
1757                 for (j=0; j < res; j++)
1758                         page_cache_release(pages[j]);
1759         kfree(pages);
1760         return res;
1761 }
1762
1763
1764 /* And unmap them... */
1765 static int
1766 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1767                     int dirtied)
1768 {
1769         int i;
1770
1771         for (i=0; i < nr_pages; i++) {
1772                 if (dirtied && !PageReserved(sgl[i].page))
1773                         SetPageDirty(sgl[i].page);
1774                 /* unlock_page(sgl[i].page); */
1775                 /* FIXME: cache flush missing for rw==READ
1776                  * FIXME: call the correct reference counting function
1777                  */
1778                 page_cache_release(sgl[i].page);
1779         }
1780
1781         return 0;
1782 }
1783
1784 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1785 #endif
1786
1787
1788 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1789 static int
1790 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1791 {
1792 #ifdef SG_ALLOW_DIO_CODE
1793         sg_io_hdr_t *hp = &srp->header;
1794         Sg_scatter_hold *schp = &srp->data;
1795         int sg_tablesize = sfp->parentdp->sg_tablesize;
1796         struct scatterlist *sgl;
1797         int mx_sc_elems, res;
1798         struct scsi_device *sdev = sfp->parentdp->device;
1799
1800         if (((unsigned long)hp->dxferp &
1801                         queue_dma_alignment(sdev->request_queue)) != 0)
1802                 return 1;
1803         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1804         if (mx_sc_elems <= 0) {
1805                 return 1;
1806         }
1807         sgl = (struct scatterlist *)schp->buffer;
1808         res = st_map_user_pages(sgl, mx_sc_elems, (unsigned long)hp->dxferp, dxfer_len,
1809                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0, ULONG_MAX);
1810         if (res <= 0)
1811                 return 1;
1812         schp->k_use_sg = res;
1813         schp->dio_in_use = 1;
1814         hp->info |= SG_INFO_DIRECT_IO;
1815         return 0;
1816 #else
1817         return 1;
1818 #endif
1819 }
1820
1821 static int
1822 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1823 {
1824         int ret_sz;
1825         int blk_size = buff_size;
1826         unsigned char *p = NULL;
1827
1828         if ((blk_size < 0) || (!sfp))
1829                 return -EFAULT;
1830         if (0 == blk_size)
1831                 ++blk_size;     /* don't know why */
1832 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1833         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1834         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1835                                    buff_size, blk_size));
1836         if (blk_size <= SG_SCATTER_SZ) {
1837                 p = sg_page_malloc(blk_size, sfp->low_dma, &ret_sz);
1838                 if (!p)
1839                         return -ENOMEM;
1840                 if (blk_size == ret_sz) {       /* got it on the first attempt */
1841                         schp->k_use_sg = 0;
1842                         schp->buffer = p;
1843                         schp->bufflen = blk_size;
1844                         schp->b_malloc_len = blk_size;
1845                         return 0;
1846                 }
1847         } else {
1848                 p = sg_page_malloc(SG_SCATTER_SZ, sfp->low_dma, &ret_sz);
1849                 if (!p)
1850                         return -ENOMEM;
1851         }
1852 /* Want some local declarations, so start new block ... */
1853         {                       /* lets try and build a scatter gather list */
1854                 struct scatterlist *sclp;
1855                 int k, rem_sz, num;
1856                 int mx_sc_elems;
1857                 int sg_tablesize = sfp->parentdp->sg_tablesize;
1858                 int first = 1;
1859
1860                 /* N.B. ret_sz carried into this block ... */
1861                 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1862                 if (mx_sc_elems < 0)
1863                         return mx_sc_elems;     /* most likely -ENOMEM */
1864
1865                 for (k = 0, sclp = schp->buffer, rem_sz = blk_size;
1866                      (rem_sz > 0) && (k < mx_sc_elems);
1867                      ++k, rem_sz -= ret_sz, ++sclp) {
1868                         if (first)
1869                                 first = 0;
1870                         else {
1871                                 num =
1872                                     (rem_sz >
1873                                      SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1874                                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1875                                 if (!p)
1876                                         break;
1877                         }
1878                         sclp->page = virt_to_page(p);
1879                         sclp->offset = offset_in_page(p);
1880                         sclp->length = ret_sz;
1881
1882                         SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1883                                           k, sg_scatg2virt(sclp), ret_sz));
1884                 }               /* end of for loop */
1885                 schp->k_use_sg = k;
1886                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1887                 schp->bufflen = blk_size;
1888                 if (rem_sz > 0) /* must have failed */
1889                         return -ENOMEM;
1890         }
1891         return 0;
1892 }
1893
1894 static int
1895 sg_write_xfer(Sg_request * srp)
1896 {
1897         sg_io_hdr_t *hp = &srp->header;
1898         Sg_scatter_hold *schp = &srp->data;
1899         int num_xfer = 0;
1900         int j, k, onum, usglen, ksglen, res;
1901         int iovec_count = (int) hp->iovec_count;
1902         int dxfer_dir = hp->dxfer_direction;
1903         unsigned char *p;
1904         unsigned char __user *up;
1905         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1906
1907         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1908             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1909                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1910                 if (schp->bufflen < num_xfer)
1911                         num_xfer = schp->bufflen;
1912         }
1913         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1914             (new_interface
1915              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1916                 return 0;
1917
1918         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1919                           num_xfer, iovec_count, schp->k_use_sg));
1920         if (iovec_count) {
1921                 onum = iovec_count;
1922                 if ((k = verify_area(VERIFY_READ, hp->dxferp,
1923                                      SZ_SG_IOVEC * onum)))
1924                         return k;
1925         } else
1926                 onum = 1;
1927
1928         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
1929                 for (j = 0, p = schp->buffer; j < onum; ++j) {
1930                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1931                         if (res)
1932                                 return res;
1933                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
1934                         if (__copy_from_user(p, up, usglen))
1935                                 return -EFAULT;
1936                         p += usglen;
1937                         num_xfer -= usglen;
1938                         if (num_xfer <= 0)
1939                                 return 0;
1940                 }
1941         } else {                /* kernel using scatter gather list */
1942                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
1943
1944                 ksglen = (int) sclp->length;
1945                 p = sg_scatg2virt(sclp);
1946                 for (j = 0, k = 0; j < onum; ++j) {
1947                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1948                         if (res)
1949                                 return res;
1950
1951                         for (; p; ++sclp, ksglen = (int) sclp->length,
1952                                   p = sg_scatg2virt(sclp)) {
1953                                 if (usglen <= 0)
1954                                         break;
1955                                 if (ksglen > usglen) {
1956                                         if (usglen >= num_xfer) {
1957                                                 if (__copy_from_user
1958                                                     (p, up, num_xfer))
1959                                                         return -EFAULT;
1960                                                 return 0;
1961                                         }
1962                                         if (__copy_from_user(p, up, usglen))
1963                                                 return -EFAULT;
1964                                         p += usglen;
1965                                         ksglen -= usglen;
1966                                         break;
1967                                 } else {
1968                                         if (ksglen >= num_xfer) {
1969                                                 if (__copy_from_user
1970                                                     (p, up, num_xfer))
1971                                                         return -EFAULT;
1972                                                 return 0;
1973                                         }
1974                                         if (__copy_from_user(p, up, ksglen))
1975                                                 return -EFAULT;
1976                                         up += ksglen;
1977                                         usglen -= ksglen;
1978                                 }
1979                                 ++k;
1980                                 if (k >= schp->k_use_sg)
1981                                         return 0;
1982                         }
1983                 }
1984         }
1985         return 0;
1986 }
1987
1988 static int
1989 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
1990            int wr_xf, int *countp, unsigned char __user **up)
1991 {
1992         int num_xfer = (int) hp->dxfer_len;
1993         unsigned char __user *p = hp->dxferp;
1994         int count, k;
1995
1996         if (0 == sg_num) {
1997                 if (wr_xf && ('\0' == hp->interface_id))
1998                         count = (int) hp->flags;        /* holds "old" input_size */
1999                 else
2000                         count = num_xfer;
2001         } else {
2002                 sg_iovec_t iovec;
2003                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
2004                         return -EFAULT;
2005                 p = iovec.iov_base;
2006                 count = (int) iovec.iov_len;
2007         }
2008         if ((k = verify_area(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count)))
2009                 return k;
2010         if (up)
2011                 *up = p;
2012         if (countp)
2013                 *countp = count;
2014         return 0;
2015 }
2016
2017 static void
2018 sg_remove_scat(Sg_scatter_hold * schp)
2019 {
2020         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2021         if (schp->buffer && (schp->sglist_len > 0)) {
2022                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2023
2024                 if (schp->dio_in_use) {
2025 #ifdef SG_ALLOW_DIO_CODE
2026                         st_unmap_user_pages(sclp, schp->k_use_sg, TRUE);
2027 #endif
2028                 } else {
2029                         int k;
2030
2031                         for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2032                              ++k, ++sclp) {
2033                                 SCSI_LOG_TIMEOUT(5, printk(
2034                                     "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
2035                                     k, sg_scatg2virt(sclp), sclp->length));
2036                                 sg_page_free(sg_scatg2virt(sclp), sclp->length);
2037                                 sclp->page = NULL;
2038                                 sclp->offset = 0;
2039                                 sclp->length = 0;
2040                         }
2041                 }
2042                 sg_page_free(schp->buffer, schp->sglist_len);
2043         } else if (schp->buffer)
2044                 sg_page_free(schp->buffer, schp->b_malloc_len);
2045         memset(schp, 0, sizeof (*schp));
2046 }
2047
2048 static int
2049 sg_read_xfer(Sg_request * srp)
2050 {
2051         sg_io_hdr_t *hp = &srp->header;
2052         Sg_scatter_hold *schp = &srp->data;
2053         int num_xfer = 0;
2054         int j, k, onum, usglen, ksglen, res;
2055         int iovec_count = (int) hp->iovec_count;
2056         int dxfer_dir = hp->dxfer_direction;
2057         unsigned char *p;
2058         unsigned char __user *up;
2059         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2060
2061         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2062             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2063                 num_xfer = hp->dxfer_len;
2064                 if (schp->bufflen < num_xfer)
2065                         num_xfer = schp->bufflen;
2066         }
2067         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2068             (new_interface
2069              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2070                 return 0;
2071
2072         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2073                           num_xfer, iovec_count, schp->k_use_sg));
2074         if (iovec_count) {
2075                 onum = iovec_count;
2076                 if ((k = verify_area(VERIFY_READ, hp->dxferp,
2077                                      SZ_SG_IOVEC * onum)))
2078                         return k;
2079         } else
2080                 onum = 1;
2081
2082         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
2083                 for (j = 0, p = schp->buffer; j < onum; ++j) {
2084                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2085                         if (res)
2086                                 return res;
2087                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
2088                         if (__copy_to_user(up, p, usglen))
2089                                 return -EFAULT;
2090                         p += usglen;
2091                         num_xfer -= usglen;
2092                         if (num_xfer <= 0)
2093                                 return 0;
2094                 }
2095         } else {                /* kernel using scatter gather list */
2096                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2097
2098                 ksglen = (int) sclp->length;
2099                 p = sg_scatg2virt(sclp);
2100                 for (j = 0, k = 0; j < onum; ++j) {
2101                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2102                         if (res)
2103                                 return res;
2104
2105                         for (; p; ++sclp, ksglen = (int) sclp->length,
2106                                   p = sg_scatg2virt(sclp)) {
2107                                 if (usglen <= 0)
2108                                         break;
2109                                 if (ksglen > usglen) {
2110                                         if (usglen >= num_xfer) {
2111                                                 if (__copy_to_user
2112                                                     (up, p, num_xfer))
2113                                                         return -EFAULT;
2114                                                 return 0;
2115                                         }
2116                                         if (__copy_to_user(up, p, usglen))
2117                                                 return -EFAULT;
2118                                         p += usglen;
2119                                         ksglen -= usglen;
2120                                         break;
2121                                 } else {
2122                                         if (ksglen >= num_xfer) {
2123                                                 if (__copy_to_user
2124                                                     (up, p, num_xfer))
2125                                                         return -EFAULT;
2126                                                 return 0;
2127                                         }
2128                                         if (__copy_to_user(up, p, ksglen))
2129                                                 return -EFAULT;
2130                                         up += ksglen;
2131                                         usglen -= ksglen;
2132                                 }
2133                                 ++k;
2134                                 if (k >= schp->k_use_sg)
2135                                         return 0;
2136                         }
2137                 }
2138         }
2139         return 0;
2140 }
2141
2142 static int
2143 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2144 {
2145         Sg_scatter_hold *schp = &srp->data;
2146
2147         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2148                                    num_read_xfer));
2149         if ((!outp) || (num_read_xfer <= 0))
2150                 return 0;
2151         if (schp->k_use_sg > 0) {
2152                 int k, num;
2153                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2154
2155                 for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2156                      ++k, ++sclp) {
2157                         num = (int) sclp->length;
2158                         if (num > num_read_xfer) {
2159                                 if (__copy_to_user
2160                                     (outp, sg_scatg2virt(sclp), num_read_xfer))
2161                                         return -EFAULT;
2162                                 break;
2163                         } else {
2164                                 if (__copy_to_user
2165                                     (outp, sg_scatg2virt(sclp), num))
2166                                         return -EFAULT;
2167                                 num_read_xfer -= num;
2168                                 if (num_read_xfer <= 0)
2169                                         break;
2170                                 outp += num;
2171                         }
2172                 }
2173         } else {
2174                 if (__copy_to_user(outp, schp->buffer, num_read_xfer))
2175                         return -EFAULT;
2176         }
2177         return 0;
2178 }
2179
2180 static void
2181 sg_build_reserve(Sg_fd * sfp, int req_size)
2182 {
2183         Sg_scatter_hold *schp = &sfp->reserve;
2184
2185         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2186         do {
2187                 if (req_size < PAGE_SIZE)
2188                         req_size = PAGE_SIZE;
2189                 if (0 == sg_build_indirect(schp, sfp, req_size))
2190                         return;
2191                 else
2192                         sg_remove_scat(schp);
2193                 req_size >>= 1; /* divide by 2 */
2194         } while (req_size > (PAGE_SIZE / 2));
2195 }
2196
2197 static void
2198 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2199 {
2200         Sg_scatter_hold *req_schp = &srp->data;
2201         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2202
2203         srp->res_used = 1;
2204         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2205         size = (size + 1) & (~1);       /* round to even for aha1542 */
2206         if (rsv_schp->k_use_sg > 0) {
2207                 int k, num;
2208                 int rem = size;
2209                 struct scatterlist *sclp =
2210                     (struct scatterlist *) rsv_schp->buffer;
2211
2212                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
2213                         num = (int) sclp->length;
2214                         if (rem <= num) {
2215                                 if (0 == k) {
2216                                         req_schp->k_use_sg = 0;
2217                                         req_schp->buffer = sg_scatg2virt(sclp);
2218                                 } else {
2219                                         sfp->save_scat_len = num;
2220                                         sclp->length = (unsigned) rem;
2221                                         req_schp->k_use_sg = k + 1;
2222                                         req_schp->sglist_len =
2223                                             rsv_schp->sglist_len;
2224                                         req_schp->buffer = rsv_schp->buffer;
2225                                 }
2226                                 req_schp->bufflen = size;
2227                                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2228                                 break;
2229                         } else
2230                                 rem -= num;
2231                 }
2232                 if (k >= rsv_schp->k_use_sg)
2233                         SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2234         } else {
2235                 req_schp->k_use_sg = 0;
2236                 req_schp->bufflen = size;
2237                 req_schp->buffer = rsv_schp->buffer;
2238                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2239         }
2240 }
2241
2242 static void
2243 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2244 {
2245         Sg_scatter_hold *req_schp = &srp->data;
2246         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2247
2248         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2249                                    (int) req_schp->k_use_sg));
2250         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2251                 struct scatterlist *sclp =
2252                     (struct scatterlist *) rsv_schp->buffer;
2253
2254                 if (sfp->save_scat_len > 0)
2255                         (sclp + (req_schp->k_use_sg - 1))->length =
2256                             (unsigned) sfp->save_scat_len;
2257                 else
2258                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2259         }
2260         req_schp->k_use_sg = 0;
2261         req_schp->bufflen = 0;
2262         req_schp->buffer = NULL;
2263         req_schp->sglist_len = 0;
2264         sfp->save_scat_len = 0;
2265         srp->res_used = 0;
2266 }
2267
2268 static Sg_request *
2269 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2270 {
2271         Sg_request *resp;
2272         unsigned long iflags;
2273
2274         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2275         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2276                 /* look for requests that are ready + not SG_IO owned */
2277                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2278                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2279                         resp->done = 2; /* guard against other readers */
2280                         break;
2281                 }
2282         }
2283         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2284         return resp;
2285 }
2286
2287 #ifdef CONFIG_SCSI_PROC_FS
2288 static Sg_request *
2289 sg_get_nth_request(Sg_fd * sfp, int nth)
2290 {
2291         Sg_request *resp;
2292         unsigned long iflags;
2293         int k;
2294
2295         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2296         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2297              ++k, resp = resp->nextrp) ;
2298         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2299         return resp;
2300 }
2301 #endif
2302
2303 /* always adds to end of list */
2304 static Sg_request *
2305 sg_add_request(Sg_fd * sfp)
2306 {
2307         int k;
2308         unsigned long iflags;
2309         Sg_request *resp;
2310         Sg_request *rp = sfp->req_arr;
2311
2312         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2313         resp = sfp->headrp;
2314         if (!resp) {
2315                 memset(rp, 0, sizeof (Sg_request));
2316                 rp->parentfp = sfp;
2317                 resp = rp;
2318                 sfp->headrp = resp;
2319         } else {
2320                 if (0 == sfp->cmd_q)
2321                         resp = NULL;    /* command queuing disallowed */
2322                 else {
2323                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2324                                 if (!rp->parentfp)
2325                                         break;
2326                         }
2327                         if (k < SG_MAX_QUEUE) {
2328                                 memset(rp, 0, sizeof (Sg_request));
2329                                 rp->parentfp = sfp;
2330                                 while (resp->nextrp)
2331                                         resp = resp->nextrp;
2332                                 resp->nextrp = rp;
2333                                 resp = rp;
2334                         } else
2335                                 resp = NULL;
2336                 }
2337         }
2338         if (resp) {
2339                 resp->nextrp = NULL;
2340                 resp->header.duration = jiffies;
2341                 resp->my_cmdp = NULL;
2342         }
2343         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2344         return resp;
2345 }
2346
2347 /* Return of 1 for found; 0 for not found */
2348 static int
2349 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2350 {
2351         Sg_request *prev_rp;
2352         Sg_request *rp;
2353         unsigned long iflags;
2354         int res = 0;
2355
2356         if ((!sfp) || (!srp) || (!sfp->headrp))
2357                 return res;
2358         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2359         prev_rp = sfp->headrp;
2360         if (srp == prev_rp) {
2361                 sfp->headrp = prev_rp->nextrp;
2362                 prev_rp->parentfp = NULL;
2363                 res = 1;
2364         } else {
2365                 while ((rp = prev_rp->nextrp)) {
2366                         if (srp == rp) {
2367                                 prev_rp->nextrp = rp->nextrp;
2368                                 rp->parentfp = NULL;
2369                                 res = 1;
2370                                 break;
2371                         }
2372                         prev_rp = rp;
2373                 }
2374         }
2375         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2376         return res;
2377 }
2378
2379 #ifdef CONFIG_SCSI_PROC_FS
2380 static Sg_fd *
2381 sg_get_nth_sfp(Sg_device * sdp, int nth)
2382 {
2383         Sg_fd *resp;
2384         unsigned long iflags;
2385         int k;
2386
2387         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2388         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2389              ++k, resp = resp->nextfp) ;
2390         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2391         return resp;
2392 }
2393 #endif
2394
2395 static Sg_fd *
2396 sg_add_sfp(Sg_device * sdp, int dev)
2397 {
2398         Sg_fd *sfp;
2399         unsigned long iflags;
2400
2401         sfp = (Sg_fd *) sg_page_malloc(sizeof (Sg_fd), 0, 0);
2402         if (!sfp)
2403                 return NULL;
2404         memset(sfp, 0, sizeof (Sg_fd));
2405         init_waitqueue_head(&sfp->read_wait);
2406         sfp->rq_list_lock = RW_LOCK_UNLOCKED;
2407
2408         sfp->timeout = SG_DEFAULT_TIMEOUT;
2409         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2410         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2411         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2412             sdp->device->host->unchecked_isa_dma : 1;
2413         sfp->cmd_q = SG_DEF_COMMAND_Q;
2414         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2415         sfp->parentdp = sdp;
2416         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2417         if (!sdp->headfp)
2418                 sdp->headfp = sfp;
2419         else {                  /* add to tail of existing list */
2420                 Sg_fd *pfp = sdp->headfp;
2421                 while (pfp->nextfp)
2422                         pfp = pfp->nextfp;
2423                 pfp->nextfp = sfp;
2424         }
2425         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2426         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2427         sg_build_reserve(sfp, sg_big_buff);
2428         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2429                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2430         return sfp;
2431 }
2432
2433 static void
2434 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2435 {
2436         Sg_fd *fp;
2437         Sg_fd *prev_fp;
2438
2439         prev_fp = sdp->headfp;
2440         if (sfp == prev_fp)
2441                 sdp->headfp = prev_fp->nextfp;
2442         else {
2443                 while ((fp = prev_fp->nextfp)) {
2444                         if (sfp == fp) {
2445                                 prev_fp->nextfp = fp->nextfp;
2446                                 break;
2447                         }
2448                         prev_fp = fp;
2449                 }
2450         }
2451         if (sfp->reserve.bufflen > 0) {
2452                 SCSI_LOG_TIMEOUT(6,
2453                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2454                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2455                 if (sfp->mmap_called)
2456                         sg_rb_correct4mmap(&sfp->reserve, 0);   /* undo correction */
2457                 sg_remove_scat(&sfp->reserve);
2458         }
2459         sfp->parentdp = NULL;
2460         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2461         sg_page_free((char *) sfp, sizeof (Sg_fd));
2462 }
2463
2464 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2465 static int
2466 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2467 {
2468         Sg_request *srp;
2469         Sg_request *tsrp;
2470         int dirty = 0;
2471         int res = 0;
2472
2473         for (srp = sfp->headrp; srp; srp = tsrp) {
2474                 tsrp = srp->nextrp;
2475                 if (srp->done)
2476                         sg_finish_rem_req(srp);
2477                 else
2478                         ++dirty;
2479         }
2480         if (0 == dirty) {
2481                 unsigned long iflags;
2482
2483                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2484                 __sg_remove_sfp(sdp, sfp);
2485                 if (sdp->detached && (NULL == sdp->headfp)) {
2486                         int k, maxd;
2487
2488                         maxd = sg_dev_max;
2489                         for (k = 0; k < maxd; ++k) {
2490                                 if (sdp == sg_dev_arr[k])
2491                                         break;
2492                         }
2493                         if (k < maxd)
2494                                 sg_dev_arr[k] = NULL;
2495                         vfree((char *) sdp);
2496                         res = 1;
2497                 }
2498                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2499         } else {
2500                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2501                 /* only bump the access_count if we actually succeeded in
2502                  * throwing another counter on the host module */
2503                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2504                 sfp->closed = 1;        /* flag dirty state on this fd */
2505                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2506                                   dirty));
2507         }
2508         return res;
2509 }
2510
2511 static int
2512 sg_res_in_use(Sg_fd * sfp)
2513 {
2514         const Sg_request *srp;
2515         unsigned long iflags;
2516
2517         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2518         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2519                 if (srp->res_used)
2520                         break;
2521         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2522         return srp ? 1 : 0;
2523 }
2524
2525 /* If retSzp==NULL want exact size or fail */
2526 static char *
2527 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2528 {
2529         char *resp = NULL;
2530         int page_mask;
2531         int order, a_size;
2532         int resSz = rqSz;
2533
2534         if (rqSz <= 0)
2535                 return resp;
2536
2537         if (lowDma)
2538                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
2539         else
2540                 page_mask = GFP_ATOMIC | __GFP_NOWARN;
2541
2542         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2543              order++, a_size <<= 1) ;
2544         resp = (char *) __get_free_pages(page_mask, order);
2545         while ((!resp) && order && retSzp) {
2546                 --order;
2547                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2548                 resp = (char *) __get_free_pages(page_mask, order);     /* try half */
2549                 resSz = a_size;
2550         }
2551         if (resp) {
2552                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2553                         memset(resp, 0, resSz);
2554                 if (retSzp)
2555                         *retSzp = resSz;
2556         }
2557         return resp;
2558 }
2559
2560 static void
2561 sg_page_free(char *buff, int size)
2562 {
2563         int order, a_size;
2564
2565         if (!buff)
2566                 return;
2567         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2568              order++, a_size <<= 1) ;
2569         free_pages((unsigned long) buff, order);
2570 }
2571
2572 static int
2573 sg_ms_to_jif(unsigned int msecs)
2574 {
2575         if ((UINT_MAX / 2U) < msecs)
2576                 return INT_MAX; /* special case, set largest possible */
2577         else
2578                 return ((int) msecs <
2579                         (INT_MAX / 1000)) ? (((int) msecs * HZ) / 1000)
2580                     : (((int) msecs / 1000) * HZ);
2581 }
2582
2583 static inline unsigned
2584 sg_jif_to_ms(int jifs)
2585 {
2586         if (jifs <= 0)
2587                 return 0U;
2588         else {
2589                 unsigned int j = (unsigned int) jifs;
2590                 return (j <
2591                         (UINT_MAX / 1000)) ? ((j * 1000) / HZ) : ((j / HZ) *
2592                                                                   1000);
2593         }
2594 }
2595
2596 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2597         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2598         MODE_SENSE, MODE_SENSE_10, LOG_SENSE
2599 };
2600
2601 static int
2602 sg_allow_access(unsigned char opcode, char dev_type)
2603 {
2604         int k;
2605
2606         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2607                 return 1;
2608         for (k = 0; k < sizeof (allow_ops); ++k) {
2609                 if (opcode == allow_ops[k])
2610                         return 1;
2611         }
2612         return 0;
2613 }
2614
2615 #ifdef CONFIG_SCSI_PROC_FS
2616 static int
2617 sg_last_dev(void)
2618 {
2619         int k;
2620         unsigned long iflags;
2621
2622         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2623         for (k = sg_dev_max - 1; k >= 0; --k)
2624                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2625                         break;
2626         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2627         return k + 1;           /* origin 1 */
2628 }
2629 #endif
2630
2631 static Sg_device *
2632 sg_get_dev(int dev)
2633 {
2634         Sg_device *sdp = NULL;
2635         unsigned long iflags;
2636
2637         if (sg_dev_arr && (dev >= 0)) {
2638                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2639                 if (dev < sg_dev_max)
2640                         sdp = sg_dev_arr[dev];
2641                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2642         }
2643         return sdp;
2644 }
2645
2646 #ifdef CONFIG_SCSI_PROC_FS
2647
2648 static struct proc_dir_entry *sg_proc_sgp = NULL;
2649
2650 static char sg_proc_sg_dirname[] = "scsi/sg";
2651
2652 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2653
2654 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2655 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2656                                   size_t count, loff_t *off);
2657 static struct file_operations adio_fops = {
2658         /* .owner, .read and .llseek added in sg_proc_init() */
2659         .open = sg_proc_single_open_adio,
2660         .write = sg_proc_write_adio,
2661         .release = single_release,
2662 };
2663
2664 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2665 static ssize_t sg_proc_write_dressz(struct file *filp,
2666                 const char __user *buffer, size_t count, loff_t *off);
2667 static struct file_operations dressz_fops = {
2668         .open = sg_proc_single_open_dressz,
2669         .write = sg_proc_write_dressz,
2670         .release = single_release,
2671 };
2672
2673 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2674 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2675 static struct file_operations version_fops = {
2676         .open = sg_proc_single_open_version,
2677         .release = single_release,
2678 };
2679
2680 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2681 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2682 static struct file_operations devhdr_fops = {
2683         .open = sg_proc_single_open_devhdr,
2684         .release = single_release,
2685 };
2686
2687 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2688 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2689 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2690 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2691 static void dev_seq_stop(struct seq_file *s, void *v);
2692 static struct file_operations dev_fops = {
2693         .open = sg_proc_open_dev,
2694         .release = seq_release,
2695 };
2696 static struct seq_operations dev_seq_ops = {
2697         .start = dev_seq_start,
2698         .next  = dev_seq_next,
2699         .stop  = dev_seq_stop,
2700         .show  = sg_proc_seq_show_dev,
2701 };
2702
2703 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2704 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2705 static struct file_operations devstrs_fops = {
2706         .open = sg_proc_open_devstrs,
2707         .release = seq_release,
2708 };
2709 static struct seq_operations devstrs_seq_ops = {
2710         .start = dev_seq_start,
2711         .next  = dev_seq_next,
2712         .stop  = dev_seq_stop,
2713         .show  = sg_proc_seq_show_devstrs,
2714 };
2715
2716 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2717 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2718 static struct file_operations debug_fops = {
2719         .open = sg_proc_open_debug,
2720         .release = seq_release,
2721 };
2722 static struct seq_operations debug_seq_ops = {
2723         .start = dev_seq_start,
2724         .next  = dev_seq_next,
2725         .stop  = dev_seq_stop,
2726         .show  = sg_proc_seq_show_debug,
2727 };
2728
2729
2730 struct sg_proc_leaf {
2731         const char * name;
2732         struct file_operations * fops;
2733 };
2734
2735 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2736         {"allow_dio", &adio_fops},
2737         {"debug", &debug_fops},
2738         {"def_reserved_size", &dressz_fops},
2739         {"device_hdr", &devhdr_fops},
2740         {"devices", &dev_fops},
2741         {"device_strs", &devstrs_fops},
2742         {"version", &version_fops}
2743 };
2744
2745 static int
2746 sg_proc_init(void)
2747 {
2748         int k, mask;
2749         int num_leaves =
2750             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2751         struct proc_dir_entry *pdep;
2752         struct sg_proc_leaf * leaf;
2753
2754         sg_proc_sgp = create_proc_entry(sg_proc_sg_dirname,
2755                                         S_IFDIR | S_IRUGO | S_IXUGO, NULL);
2756         if (!sg_proc_sgp)
2757                 return 1;
2758         for (k = 0; k < num_leaves; ++k) {
2759                 leaf = &sg_proc_leaf_arr[k];
2760                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2761                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2762                 if (pdep) {
2763                         leaf->fops->owner = THIS_MODULE,
2764                         leaf->fops->read = seq_read,
2765                         leaf->fops->llseek = seq_lseek,
2766                         pdep->proc_fops = leaf->fops;
2767                 }
2768         }
2769         return 0;
2770 }
2771
2772 static void
2773 sg_proc_cleanup(void)
2774 {
2775         int k;
2776         int num_leaves =
2777             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2778
2779         if (!sg_proc_sgp)
2780                 return;
2781         for (k = 0; k < num_leaves; ++k)
2782                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2783         remove_proc_entry(sg_proc_sg_dirname, NULL);
2784 }
2785
2786
2787 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2788 {
2789         seq_printf(s, "%d\n", *((int *)s->private));
2790         return 0;
2791 }
2792
2793 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2794 {
2795         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2796 }
2797
2798 static ssize_t
2799 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2800                    size_t count, loff_t *off)
2801 {
2802         int num;
2803         char buff[11];
2804
2805         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2806                 return -EACCES;
2807         num = (count < 10) ? count : 10;
2808         if (copy_from_user(buff, buffer, num))
2809                 return -EFAULT;
2810         buff[num] = '\0';
2811         sg_allow_dio = simple_strtoul(buff, 0, 10) ? 1 : 0;
2812         return count;
2813 }
2814
2815 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2816 {
2817         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2818 }
2819
2820 static ssize_t
2821 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2822                      size_t count, loff_t *off)
2823 {
2824         int num;
2825         unsigned long k = ULONG_MAX;
2826         char buff[11];
2827
2828         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2829                 return -EACCES;
2830         num = (count < 10) ? count : 10;
2831         if (copy_from_user(buff, buffer, num))
2832                 return -EFAULT;
2833         buff[num] = '\0';
2834         k = simple_strtoul(buff, 0, 10);
2835         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2836                 sg_big_buff = k;
2837                 return count;
2838         }
2839         return -ERANGE;
2840 }
2841
2842 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2843 {
2844         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2845                    sg_version_date);
2846         return 0;
2847 }
2848
2849 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2850 {
2851         return single_open(file, sg_proc_seq_show_version, NULL);
2852 }
2853
2854 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2855 {
2856         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2857                    "online\n");
2858         return 0;
2859 }
2860
2861 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2862 {
2863         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2864 }
2865
2866 struct sg_proc_deviter {
2867         loff_t  index;
2868         size_t  max;
2869 };
2870
2871 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2872 {
2873         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2874
2875         if (! it)
2876                 return NULL;
2877         if (NULL == sg_dev_arr)
2878                 goto err1;
2879         it->index = *pos;
2880         it->max = sg_last_dev();
2881         if (it->index >= it->max)
2882                 goto err1;
2883         return it;
2884 err1:
2885         kfree(it);
2886         return NULL;
2887 }
2888
2889 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2890 {
2891         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2892
2893         *pos = ++it->index;
2894         return (it->index < it->max) ? it : NULL;
2895 }
2896
2897 static void dev_seq_stop(struct seq_file *s, void *v)
2898 {
2899         kfree (v);
2900 }
2901
2902 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2903 {
2904         return seq_open(file, &dev_seq_ops);
2905 }
2906
2907 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2908 {
2909         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2910         Sg_device *sdp;
2911         struct scsi_device *scsidp;
2912
2913         sdp = it ? sg_get_dev(it->index) : NULL;
2914         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2915                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2916                               scsidp->host->host_no, scsidp->channel,
2917                               scsidp->id, scsidp->lun, (int) scsidp->type,
2918                               1,
2919                               (int) scsidp->queue_depth,
2920                               (int) scsidp->device_busy,
2921                               (int) scsi_device_online(scsidp));
2922         else
2923                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2924         return 0;
2925 }
2926
2927 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2928 {
2929         return seq_open(file, &devstrs_seq_ops);
2930 }
2931
2932 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2933 {
2934         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2935         Sg_device *sdp;
2936         struct scsi_device *scsidp;
2937
2938         sdp = it ? sg_get_dev(it->index) : NULL;
2939         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2940                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2941                            scsidp->vendor, scsidp->model, scsidp->rev);
2942         else
2943                 seq_printf(s, "<no active device>\n");
2944         return 0;
2945 }
2946
2947 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2948 {
2949         int k, m, new_interface, blen, usg;
2950         Sg_request *srp;
2951         Sg_fd *fp;
2952         const sg_io_hdr_t *hp;
2953         const char * cp;
2954
2955         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2956                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2957                            "(res)sgat=%d low_dma=%d\n", k + 1,
2958                            sg_jif_to_ms(fp->timeout),
2959                            fp->reserve.bufflen,
2960                            (int) fp->reserve.k_use_sg,
2961                            (int) fp->low_dma);
2962                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2963                            (int) fp->cmd_q, (int) fp->force_packid,
2964                            (int) fp->keep_orphan, (int) fp->closed);
2965                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2966                         hp = &srp->header;
2967                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2968                         if (srp->res_used) {
2969                                 if (new_interface &&
2970                                     (SG_FLAG_MMAP_IO & hp->flags))
2971                                         cp = "     mmap>> ";
2972                                 else
2973                                         cp = "     rb>> ";
2974                         } else {
2975                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2976                                         cp = "     dio>> ";
2977                                 else
2978                                         cp = "     ";
2979                         }
2980                         seq_printf(s, cp);
2981                         blen = srp->my_cmdp ?
2982                                 srp->my_cmdp->sr_bufflen : srp->data.bufflen;
2983                         usg = srp->my_cmdp ?
2984                                 srp->my_cmdp->sr_use_sg : srp->data.k_use_sg;
2985                         seq_printf(s, srp->done ?
2986                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2987                                    : (srp->my_cmdp ? "act:" : "prior:"));
2988                         seq_printf(s, " id=%d blen=%d",
2989                                    srp->header.pack_id, blen);
2990                         if (srp->done)
2991                                 seq_printf(s, " dur=%d", hp->duration);
2992                         else
2993                                 seq_printf(s, " t_o/elap=%d/%d",
2994                                   new_interface ? hp->timeout : sg_jif_to_ms(fp->timeout),
2995                                   sg_jif_to_ms(hp->duration ? (jiffies - hp->duration) : 0));
2996                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2997                                    (int) srp->data.cmd_opcode);
2998                 }
2999                 if (0 == m)
3000                         seq_printf(s, "     No requests active\n");
3001         }
3002 }
3003
3004 static int sg_proc_open_debug(struct inode *inode, struct file *file)
3005 {
3006         return seq_open(file, &debug_seq_ops);
3007 }
3008
3009 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
3010 {
3011         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3012         Sg_device *sdp;
3013
3014         if (it && (0 == it->index)) {
3015                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
3016                            "(origin 1)\n", sg_dev_max, (int)it->max);
3017                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
3018         }
3019         sdp = it ? sg_get_dev(it->index) : NULL;
3020         if (sdp) {
3021                 struct scsi_device *scsidp = sdp->device;
3022
3023                 if (NULL == scsidp) {
3024                         seq_printf(s, "device %d detached ??\n",
3025                                    (int)it->index);
3026                         return 0;
3027                 }
3028
3029                 if (sg_get_nth_sfp(sdp, 0)) {
3030                         seq_printf(s, " >>> device=%s ",
3031                                 sdp->disk->disk_name);
3032                         if (sdp->detached)
3033                                 seq_printf(s, "detached pending close ");
3034                         else
3035                                 seq_printf
3036                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
3037                                      scsidp->host->host_no,
3038                                      scsidp->channel, scsidp->id,
3039                                      scsidp->lun,
3040                                      scsidp->host->hostt->emulated);
3041                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
3042                                    sdp->sg_tablesize, sdp->exclude);
3043                 }
3044                 sg_proc_debug_helper(s, sdp);
3045         }
3046         return 0;
3047 }
3048
3049 #endif                          /* CONFIG_SCSI_PROC_FS */
3050
3051 module_init(init_sg);
3052 module_exit(exit_sg);
3053 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);