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