drivers/scsi/sg.c

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