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         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
 238         sdp = sg_get_dev(dev);
 239         if ((!sdp) || (!sdp->device))
 240                 return -ENXIO;
 241         if (sdp->detached)
 242                 return -ENODEV;
 243
 244         /* scsi generic is only for non-disk, non-cd, non-tape devices */
 245         if ( (sdp->device->type == TYPE_DISK) || (sdp->device->type == TYPE_MOD) || (sdp->device->type == TYPE_ROM)
 246            || (sdp->device->type == TYPE_WORM) || ( sdp->device->type == TYPE_TAPE))
 247                 printk(KERN_WARNING "%s: Using deprecated /dev/sg mechanism instead of SG_IO on the actual device\n",current->comm);
 248
 249
 250         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 251         /* Prevent the device driver from vanishing while we sleep */
 252         retval = scsi_device_get(sdp->device);
 253         if (retval)
 254                 return retval;
 255
 256         if (!((flags & O_NONBLOCK) ||
 257               scsi_block_when_processing_errors(sdp->device))) {
 258                 retval = -ENXIO;
 259                 /* we are in error recovery for this device */
 260                 goto error_out;
 261         }
 262
 263         if (flags & O_EXCL) {
 264                 if (O_RDONLY == (flags & O_ACCMODE)) {
 265                         retval = -EPERM; /* Can't lock it with read only access */
 266                         goto error_out;
 267                 }
 268                 if (sdp->headfp && (flags & O_NONBLOCK)) {
 269                         retval = -EBUSY;
 270                         goto error_out;
 271                 }
 272                 res = 0;
 273                 __wait_event_interruptible(sdp->o_excl_wait,
 274                         ((sdp->headfp || sdp->exclude) ? 0 : (sdp->exclude = 1)), res);
 275                 if (res) {
 276                         retval = res;   /* -ERESTARTSYS because signal hit process */
 277                         goto error_out;
 278                 }
 279         } else if (sdp->exclude) {      /* some other fd has an exclusive lock on dev */
 280                 if (flags & O_NONBLOCK) {
 281                         retval = -EBUSY;
 282                         goto error_out;
 283                 }
 284                 res = 0;
 285                 __wait_event_interruptible(sdp->o_excl_wait, (!sdp->exclude),
 286                                            res);
 287                 if (res) {
 288                         retval = res;   /* -ERESTARTSYS because signal hit process */
 289                         goto error_out;
 290                 }
 291         }
 292         if (sdp->detached) {
 293                 retval = -ENODEV;
 294                 goto error_out;
 295         }
 296         if (!sdp->headfp) {     /* no existing opens on this device */
 297                 sdp->sgdebug = 0;
 298                 sdp->sg_tablesize = sdp->device->host->sg_tablesize;
 299         }
 300         if ((sfp = sg_add_sfp(sdp, dev)))
 301                 filp->private_data = sfp;
 302         else {
 303                 if (flags & O_EXCL)
 304                         sdp->exclude = 0;       /* undo if error */
 305                 retval = -ENOMEM;
 306                 goto error_out;
 307         }
 308         return 0;
 309
 310       error_out:
 311         scsi_device_put(sdp->device);
 312         return retval;
 313 }
 314
 315 /* Following function was formerly called 'sg_close' */
 316 static int
 317 sg_release(struct inode *inode, struct file *filp)
 318 {
 319         Sg_device *sdp;
 320         Sg_fd *sfp;
 321
 322         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 323                 return -ENXIO;
 324         SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name));
 325         sg_fasync(-1, filp, 0); /* remove filp from async notification list */
 326         if (0 == sg_remove_sfp(sdp, sfp)) {     /* Returns 1 when sdp gone */
 327                 if (!sdp->detached) {
 328                         scsi_device_put(sdp->device);
 329                 }
 330                 sdp->exclude = 0;
 331                 wake_up_interruptible(&sdp->o_excl_wait);
 332         }
 333         return 0;
 334 }
 335
 336 static ssize_t
 337 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 338 {
 339         int k, res;
 340         Sg_device *sdp;
 341         Sg_fd *sfp;
 342         Sg_request *srp;
 343         int req_pack_id = -1;
 344         struct sg_header old_hdr;
 345         sg_io_hdr_t new_hdr;
 346         sg_io_hdr_t *hp;
 347
 348         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 349                 return -ENXIO;
 350         SCSI_LOG_TIMEOUT(3, printk("sg_read: %s, count=%d\n",
 351                                    sdp->disk->disk_name, (int) count));
 352         if (ppos != &filp->f_pos) ;     /* FIXME: Hmm.  Seek to the right place, or fail?  */
 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         if (ppos != &filp->f_pos) ;     /* FIXME: Hmm.  Seek to the right place, or fail?  */
 511
 512         if ((k = verify_area(VERIFY_READ, buf, count)))
 513                 return k;       /* protects following copy_from_user()s + get_user()s */
 514         if (count < SZ_SG_HEADER)
 515                 return -EIO;
 516         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 517                 return -EFAULT;
 518         blocking = !(filp->f_flags & O_NONBLOCK);
 519         if (old_hdr.reply_len < 0)
 520                 return sg_new_write(sfp, buf, count, blocking, 0, NULL);
 521         if (count < (SZ_SG_HEADER + 6))
 522                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 523
 524         if (!(srp = sg_add_request(sfp))) {
 525                 SCSI_LOG_TIMEOUT(1, printk("sg_write: queue full\n"));
 526                 return -EDOM;
 527         }
 528         buf += SZ_SG_HEADER;
 529         __get_user(opcode, buf);
 530         if (sfp->next_cmd_len > 0) {
 531                 if (sfp->next_cmd_len > MAX_COMMAND_SIZE) {
 532                         SCSI_LOG_TIMEOUT(1, printk("sg_write: command length too long\n"));
 533                         sfp->next_cmd_len = 0;
 534                         sg_remove_request(sfp, srp);
 535                         return -EIO;
 536                 }
 537                 cmd_size = sfp->next_cmd_len;
 538                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 539         } else {
 540                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 541                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 542                         cmd_size = 12;
 543         }
 544         SCSI_LOG_TIMEOUT(4, printk(
 545                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 546 /* Determine buffer size.  */
 547         input_size = count - cmd_size;
 548         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 549         mxsize -= SZ_SG_HEADER;
 550         input_size -= SZ_SG_HEADER;
 551         if (input_size < 0) {
 552                 sg_remove_request(sfp, srp);
 553                 return -EIO;    /* User did not pass enough bytes for this command. */
 554         }
 555         hp = &srp->header;
 556         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 557         hp->cmd_len = (unsigned char) cmd_size;
 558         hp->iovec_count = 0;
 559         hp->mx_sb_len = 0;
 560         if (input_size > 0)
 561                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 562                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 563         else
 564                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 565         hp->dxfer_len = mxsize;
 566         hp->dxferp = (char __user *)buf + cmd_size;
 567         hp->sbp = NULL;
 568         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 569         hp->flags = input_size; /* structure abuse ... */
 570         hp->pack_id = old_hdr.pack_id;
 571         hp->usr_ptr = NULL;
 572         if (__copy_from_user(cmnd, buf, cmd_size))
 573                 return -EFAULT;
 574         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 575         return (k < 0) ? k : count;
 576 }
 577
 578 static ssize_t
 579 sg_new_write(Sg_fd * sfp, const char __user *buf, size_t count,
 580              int blocking, int read_only, Sg_request ** o_srp)
 581 {
 582         int k;
 583         Sg_request *srp;
 584         sg_io_hdr_t *hp;
 585         unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
 586         int timeout;
 587
 588         if (count < SZ_SG_IO_HDR)
 589                 return -EINVAL;
 590         if ((k = verify_area(VERIFY_READ, buf, count)))
 591                 return k; /* protects following copy_from_user()s + get_user()s */
 592
 593         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 594         if (!(srp = sg_add_request(sfp))) {
 595                 SCSI_LOG_TIMEOUT(1, printk("sg_new_write: queue full\n"));
 596                 return -EDOM;
 597         }
 598         hp = &srp->header;
 599         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 600                 sg_remove_request(sfp, srp);
 601                 return -EFAULT;
 602         }
 603         if (hp->interface_id != 'S') {
 604                 sg_remove_request(sfp, srp);
 605                 return -ENOSYS;
 606         }
 607         if (hp->flags & SG_FLAG_MMAP_IO) {
 608                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 609                         sg_remove_request(sfp, srp);
 610                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 611                 }
 612                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 613                         sg_remove_request(sfp, srp);
 614                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 615                 }
 616                 if (sg_res_in_use(sfp)) {
 617                         sg_remove_request(sfp, srp);
 618                         return -EBUSY;  /* reserve buffer already being used */
 619                 }
 620         }
 621         timeout = sg_ms_to_jif(srp->header.timeout);
 622         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 623                 sg_remove_request(sfp, srp);
 624                 return -EMSGSIZE;
 625         }
 626         if ((k = verify_area(VERIFY_READ, hp->cmdp, hp->cmd_len))) {
 627                 sg_remove_request(sfp, srp);
 628                 return k;       /* protects following copy_from_user()s + get_user()s */
 629         }
 630         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 631                 sg_remove_request(sfp, srp);
 632                 return -EFAULT;
 633         }
 634         if (read_only &&
 635             (!sg_allow_access(cmnd[0], sfp->parentdp->device->type))) {
 636                 sg_remove_request(sfp, srp);
 637                 return -EPERM;
 638         }
 639         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 640         if (k < 0)
 641                 return k;
 642         if (o_srp)
 643                 *o_srp = srp;
 644         return count;
 645 }
 646
 647 static int
 648 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 649                 unsigned char *cmnd, int timeout, int blocking)
 650 {
 651         int k;
 652         Scsi_Request *SRpnt;
 653         Sg_device *sdp = sfp->parentdp;
 654         sg_io_hdr_t *hp = &srp->header;
 655         request_queue_t *q;
 656
 657         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 658         hp->status = 0;
 659         hp->masked_status = 0;
 660         hp->msg_status = 0;
 661         hp->info = 0;
 662         hp->host_status = 0;
 663         hp->driver_status = 0;
 664         hp->resid = 0;
 665         SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 666                           (int) cmnd[0], (int) hp->cmd_len));
 667
 668         if ((k = sg_start_req(srp))) {
 669                 SCSI_LOG_TIMEOUT(1, printk("sg_write: start_req err=%d\n", k));
 670                 sg_finish_rem_req(srp);
 671                 return k;       /* probably out of space --> ENOMEM */
 672         }
 673         if ((k = sg_write_xfer(srp))) {
 674                 SCSI_LOG_TIMEOUT(1, printk("sg_write: write_xfer, bad address\n"));
 675                 sg_finish_rem_req(srp);
 676                 return k;
 677         }
 678         if (sdp->detached) {
 679                 sg_finish_rem_req(srp);
 680                 return -ENODEV;
 681         }
 682         SRpnt = scsi_allocate_request(sdp->device, GFP_ATOMIC);
 683         if (SRpnt == NULL) {
 684                 SCSI_LOG_TIMEOUT(1, printk("sg_write: no mem\n"));
 685                 sg_finish_rem_req(srp);
 686                 return -ENOMEM;
 687         }
 688
 689         srp->my_cmdp = SRpnt;
 690         q = SRpnt->sr_device->request_queue;
 691         SRpnt->sr_request->rq_disk = sdp->disk;
 692         SRpnt->sr_sense_buffer[0] = 0;
 693         SRpnt->sr_cmd_len = hp->cmd_len;
 694         SRpnt->sr_use_sg = srp->data.k_use_sg;
 695         SRpnt->sr_sglist_len = srp->data.sglist_len;
 696         SRpnt->sr_bufflen = srp->data.bufflen;
 697         SRpnt->sr_underflow = 0;
 698         SRpnt->sr_buffer = srp->data.buffer;
 699         switch (hp->dxfer_direction) {
 700         case SG_DXFER_TO_FROM_DEV:
 701         case SG_DXFER_FROM_DEV:
 702                 SRpnt->sr_data_direction = SCSI_DATA_READ;
 703                 break;
 704         case SG_DXFER_TO_DEV:
 705                 SRpnt->sr_data_direction = SCSI_DATA_WRITE;
 706                 break;
 707         case SG_DXFER_UNKNOWN:
 708                 SRpnt->sr_data_direction = SCSI_DATA_UNKNOWN;
 709                 break;
 710         default:
 711                 SRpnt->sr_data_direction = SCSI_DATA_NONE;
 712                 break;
 713         }
 714         SRpnt->upper_private_data = srp;
 715         srp->data.k_use_sg = 0;
 716         srp->data.sglist_len = 0;
 717         srp->data.bufflen = 0;
 718         srp->data.buffer = NULL;
 719         hp->duration = jiffies; /* unit jiffies now, millisecs after done */
 720 /* Now send everything of to mid-level. The next time we hear about this
 721    packet is when sg_cmd_done() is called (i.e. a callback). */
 722         scsi_do_req(SRpnt, (void *) cmnd,
 723                     (void *) SRpnt->sr_buffer, hp->dxfer_len,
 724                     sg_cmd_done, timeout, SG_DEFAULT_RETRIES);
 725         /* dxfer_len overwrites SRpnt->sr_bufflen, hence need for b_malloc_len */
 726         return 0;
 727 }
 728
 729 static inline unsigned
 730 sg_jif_to_ms(int jifs)
 731 {
 732         if (jifs <= 0)
 733                 return 0U;
 734         else {
 735                 unsigned int j = (unsigned int) jifs;
 736                 return (j <
 737                         (UINT_MAX / 1000)) ? ((j * 1000) / HZ) : ((j / HZ) *
 738                                                                   1000);
 739         }
 740 }
 741
 742 static int
 743 sg_ioctl(struct inode *inode, struct file *filp,
 744          unsigned int cmd_in, unsigned long arg)
 745 {
 746         void __user *p = (void __user *)arg;
 747         int __user *ip = p;
 748         int result, val, read_only;
 749         Sg_device *sdp;
 750         Sg_fd *sfp;
 751         Sg_request *srp;
 752         unsigned long iflags;
 753
 754         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 755                 return -ENXIO;
 756         SCSI_LOG_TIMEOUT(3, printk("sg_ioctl: %s, cmd=0x%x\n",
 757                                    sdp->disk->disk_name, (int) cmd_in));
 758         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 759
 760         switch (cmd_in) {
 761         case SG_IO:
 762                 {
 763                         int blocking = 1;       /* ignore O_NONBLOCK flag */
 764
 765                         if (sdp->detached)
 766                                 return -ENODEV;
 767                         if (!scsi_block_when_processing_errors(sdp->device))
 768                                 return -ENXIO;
 769                         result = verify_area(VERIFY_WRITE, p, SZ_SG_IO_HDR);
 770                         if (result)
 771                                 return result;
 772                         result =
 773                             sg_new_write(sfp, p, SZ_SG_IO_HDR,
 774                                          blocking, read_only, &srp);
 775                         if (result < 0)
 776                                 return result;
 777                         srp->sg_io_owned = 1;
 778                         while (1) {
 779                                 result = 0;     /* following macro to beat race condition */
 780                                 __wait_event_interruptible(sfp->read_wait,
 781                                         (sdp->detached || sfp->closed || srp->done),
 782                                                            result);
 783                                 if (sdp->detached)
 784                                         return -ENODEV;
 785                                 if (sfp->closed)
 786                                         return 0;       /* request packet dropped already */
 787                                 if (0 == result)
 788                                         break;
 789                                 srp->orphan = 1;
 790                                 return result;  /* -ERESTARTSYS because signal hit process */
 791                         }
 792                         srp->done = 2;
 793                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 794                         return (result < 0) ? result : 0;
 795                 }
 796         case SG_SET_TIMEOUT:
 797                 result = get_user(val, ip);
 798                 if (result)
 799                         return result;
 800                 if (val < 0)
 801                         return -EIO;
 802                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 803                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 804                 sfp->timeout_user = val;
 805                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 806
 807                 return 0;
 808         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 809                                 /* strange ..., for backward compatibility */
 810                 return sfp->timeout_user;
 811         case SG_SET_FORCE_LOW_DMA:
 812                 result = get_user(val, ip);
 813                 if (result)
 814                         return result;
 815                 if (val) {
 816                         sfp->low_dma = 1;
 817                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 818                                 val = (int) sfp->reserve.bufflen;
 819                                 sg_remove_scat(&sfp->reserve);
 820                                 sg_build_reserve(sfp, val);
 821                         }
 822                 } else {
 823                         if (sdp->detached)
 824                                 return -ENODEV;
 825                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 826                 }
 827                 return 0;
 828         case SG_GET_LOW_DMA:
 829                 return put_user((int) sfp->low_dma, ip);
 830         case SG_GET_SCSI_ID:
 831                 result =
 832                     verify_area(VERIFY_WRITE, p, sizeof (sg_scsi_id_t));
 833                 if (result)
 834                         return result;
 835                 else {
 836                         sg_scsi_id_t __user *sg_idp = p;
 837
 838                         if (sdp->detached)
 839                                 return -ENODEV;
 840                         __put_user((int) sdp->device->host->host_no,
 841                                    &sg_idp->host_no);
 842                         __put_user((int) sdp->device->channel,
 843                                    &sg_idp->channel);
 844                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 845                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 846                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 847                         __put_user((short) sdp->device->host->cmd_per_lun,
 848                                    &sg_idp->h_cmd_per_lun);
 849                         __put_user((short) sdp->device->queue_depth,
 850                                    &sg_idp->d_queue_depth);
 851                         __put_user(0, &sg_idp->unused[0]);
 852                         __put_user(0, &sg_idp->unused[1]);
 853                         return 0;
 854                 }
 855         case SG_SET_FORCE_PACK_ID:
 856                 result = get_user(val, ip);
 857                 if (result)
 858                         return result;
 859                 sfp->force_packid = val ? 1 : 0;
 860                 return 0;
 861         case SG_GET_PACK_ID:
 862                 result = verify_area(VERIFY_WRITE, ip, sizeof (int));
 863                 if (result)
 864                         return result;
 865                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 866                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 867                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 868                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 869                                                        iflags);
 870                                 __put_user(srp->header.pack_id, ip);
 871                                 return 0;
 872                         }
 873                 }
 874                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 875                 __put_user(-1, ip);
 876                 return 0;
 877         case SG_GET_NUM_WAITING:
 878                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 879                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 880                         if ((1 == srp->done) && (!srp->sg_io_owned))
 881                                 ++val;
 882                 }
 883                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 884                 return put_user(val, ip);
 885         case SG_GET_SG_TABLESIZE:
 886                 return put_user(sdp->sg_tablesize, ip);
 887         case SG_SET_RESERVED_SIZE:
 888                 result = get_user(val, ip);
 889                 if (result)
 890                         return result;
 891                 if (val < 0)
 892                         return -EINVAL;
 893                 if (val != sfp->reserve.bufflen) {
 894                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 895                                 return -EBUSY;
 896                         sg_remove_scat(&sfp->reserve);
 897                         sg_build_reserve(sfp, val);
 898                 }
 899                 return 0;
 900         case SG_GET_RESERVED_SIZE:
 901                 val = (int) sfp->reserve.bufflen;
 902                 return put_user(val, ip);
 903         case SG_SET_COMMAND_Q:
 904                 result = get_user(val, ip);
 905                 if (result)
 906                         return result;
 907                 sfp->cmd_q = val ? 1 : 0;
 908                 return 0;
 909         case SG_GET_COMMAND_Q:
 910                 return put_user((int) sfp->cmd_q, ip);
 911         case SG_SET_KEEP_ORPHAN:
 912                 result = get_user(val, ip);
 913                 if (result)
 914                         return result;
 915                 sfp->keep_orphan = val;
 916                 return 0;
 917         case SG_GET_KEEP_ORPHAN:
 918                 return put_user((int) sfp->keep_orphan, ip);
 919         case SG_NEXT_CMD_LEN:
 920                 result = get_user(val, ip);
 921                 if (result)
 922                         return result;
 923                 sfp->next_cmd_len = (val > 0) ? val : 0;
 924                 return 0;
 925         case SG_GET_VERSION_NUM:
 926                 return put_user(sg_version_num, ip);
 927         case SG_GET_ACCESS_COUNT:
 928                 /* faked - we don't have a real access count anymore */
 929                 val = (sdp->device ? 1 : 0);
 930                 return put_user(val, ip);
 931         case SG_GET_REQUEST_TABLE:
 932                 result = verify_area(VERIFY_WRITE, p,
 933                                      SZ_SG_REQ_INFO * SG_MAX_QUEUE);
 934                 if (result)
 935                         return result;
 936                 else {
 937                         sg_req_info_t rinfo[SG_MAX_QUEUE];
 938                         Sg_request *srp;
 939                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
 940                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
 941                              ++val, srp = srp ? srp->nextrp : srp) {
 942                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
 943                                 if (srp) {
 944                                         rinfo[val].req_state = srp->done + 1;
 945                                         rinfo[val].problem =
 946                                             srp->header.masked_status &
 947                                             srp->header.host_status &
 948                                             srp->header.driver_status;
 949                                         rinfo[val].duration =
 950                                             srp->done ? srp->header.duration :
 951                                             sg_jif_to_ms(
 952                                                 jiffies - srp->header.duration);
 953                                         rinfo[val].orphan = srp->orphan;
 954                                         rinfo[val].sg_io_owned = srp->sg_io_owned;
 955                                         rinfo[val].pack_id = srp->header.pack_id;
 956                                         rinfo[val].usr_ptr = srp->header.usr_ptr;
 957                                 }
 958                         }
 959                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 960                         return (__copy_to_user(p, rinfo,
 961                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE) ? -EFAULT : 0);
 962                 }
 963         case SG_EMULATED_HOST:
 964                 if (sdp->detached)
 965                         return -ENODEV;
 966                 return put_user(sdp->device->host->hostt->emulated, ip);
 967         case SG_SCSI_RESET:
 968                 if (sdp->detached)
 969                         return -ENODEV;
 970                 if (filp->f_flags & O_NONBLOCK) {
 971                         if (test_bit(SHOST_RECOVERY,
 972                                      &sdp->device->host->shost_state))
 973                                 return -EBUSY;
 974                 } else if (!scsi_block_when_processing_errors(sdp->device))
 975                         return -EBUSY;
 976                 result = get_user(val, ip);
 977                 if (result)
 978                         return result;
 979                 if (SG_SCSI_RESET_NOTHING == val)
 980                         return 0;
 981                 switch (val) {
 982                 case SG_SCSI_RESET_DEVICE:
 983                         val = SCSI_TRY_RESET_DEVICE;
 984                         break;
 985                 case SG_SCSI_RESET_BUS:
 986                         val = SCSI_TRY_RESET_BUS;
 987                         break;
 988                 case SG_SCSI_RESET_HOST:
 989                         val = SCSI_TRY_RESET_HOST;
 990                         break;
 991                 default:
 992                         return -EINVAL;
 993                 }
 994                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 995                         return -EACCES;
 996                 return (scsi_reset_provider(sdp->device, val) ==
 997                         SUCCESS) ? 0 : -EIO;
 998         case SCSI_IOCTL_SEND_COMMAND:
 999                 if (sdp->detached)
1000                         return -ENODEV;
1001                 if (read_only) {
1002                         unsigned char opcode = WRITE_6;
1003                         Scsi_Ioctl_Command __user *siocp = p;
1004
1005                         if (copy_from_user(&opcode, siocp->data, 1))
1006                                 return -EFAULT;
1007                         if (!sg_allow_access(opcode, sdp->device->type))
1008                                 return -EPERM;
1009                 }
1010                 return scsi_ioctl_send_command(sdp->device, p);
1011         case SG_SET_DEBUG:
1012                 result = get_user(val, ip);
1013                 if (result)
1014                         return result;
1015                 sdp->sgdebug = (char) val;
1016                 return 0;
1017         case SCSI_IOCTL_GET_IDLUN:
1018         case SCSI_IOCTL_GET_BUS_NUMBER:
1019         case SCSI_IOCTL_PROBE_HOST:
1020         case SG_GET_TRANSFORM:
1021                 if (sdp->detached)
1022                         return -ENODEV;
1023                 return scsi_ioctl(sdp->device, cmd_in, p);
1024         default:
1025                 if (read_only)
1026                         return -EPERM;  /* don't know so take safe approach */
1027                 return scsi_ioctl(sdp->device, cmd_in, p);
1028         }
1029 }
1030
1031 static unsigned int
1032 sg_poll(struct file *filp, poll_table * wait)
1033 {
1034         unsigned int res = 0;
1035         Sg_device *sdp;
1036         Sg_fd *sfp;
1037         Sg_request *srp;
1038         int count = 0;
1039         unsigned long iflags;
1040
1041         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
1042             || sfp->closed)
1043                 return POLLERR;
1044         poll_wait(filp, &sfp->read_wait, wait);
1045         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1046         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1047                 /* if any read waiting, flag it */
1048                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1049                         res = POLLIN | POLLRDNORM;
1050                 ++count;
1051         }
1052         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1053
1054         if (sdp->detached)
1055                 res |= POLLHUP;
1056         else if (!sfp->cmd_q) {
1057                 if (0 == count)
1058                         res |= POLLOUT | POLLWRNORM;
1059         } else if (count < SG_MAX_QUEUE)
1060                 res |= POLLOUT | POLLWRNORM;
1061         SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
1062                                    sdp->disk->disk_name, (int) res));
1063         return res;
1064 }
1065
1066 static int
1067 sg_fasync(int fd, struct file *filp, int mode)
1068 {
1069         int retval;
1070         Sg_device *sdp;
1071         Sg_fd *sfp;
1072
1073         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1074                 return -ENXIO;
1075         SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
1076                                    sdp->disk->disk_name, mode));
1077
1078         retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
1079         return (retval < 0) ? retval : 0;
1080 }
1081
1082 static inline unsigned char *
1083 sg_scatg2virt(const struct scatterlist *sclp)
1084 {
1085         return (sclp && sclp->page) ?
1086             (unsigned char *) page_address(sclp->page) + sclp->offset : NULL;
1087 }
1088
1089 /* When startFinish==1 increments page counts for pages other than the
1090    first of scatter gather elements obtained from __get_free_pages().
1091    When startFinish==0 decrements ... */
1092 static void
1093 sg_rb_correct4mmap(Sg_scatter_hold * rsv_schp, int startFinish)
1094 {
1095         void *page_ptr;
1096         struct page *page;
1097         int k, m;
1098
1099         SCSI_LOG_TIMEOUT(3, printk("sg_rb_correct4mmap: startFinish=%d, scatg=%d\n",
1100                                    startFinish, rsv_schp->k_use_sg));
1101         /* N.B. correction _not_ applied to base page of each allocation */
1102         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1103                 struct scatterlist *sclp = rsv_schp->buffer;
1104
1105                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
1106                         for (m = PAGE_SIZE; m < sclp->length; m += PAGE_SIZE) {
1107                                 page_ptr = sg_scatg2virt(sclp) + m;
1108                                 page = virt_to_page(page_ptr);
1109                                 if (startFinish)
1110                                         get_page(page);
1111                                 else {
1112                                         if (page_count(page) > 0)
1113                                                 __put_page(page);
1114                                 }
1115                         }
1116                 }
1117         } else {                /* reserve buffer is just a single allocation */
1118                 for (m = PAGE_SIZE; m < rsv_schp->bufflen; m += PAGE_SIZE) {
1119                         page_ptr = (unsigned char *) rsv_schp->buffer + m;
1120                         page = virt_to_page(page_ptr);
1121                         if (startFinish)
1122                                 get_page(page);
1123                         else {
1124                                 if (page_count(page) > 0)
1125                                         __put_page(page);
1126                         }
1127                 }
1128         }
1129 }
1130
1131 static struct page *
1132 sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
1133 {
1134         Sg_fd *sfp;
1135         struct page *page = NOPAGE_SIGBUS;
1136         void *page_ptr = NULL;
1137         unsigned long offset;
1138         Sg_scatter_hold *rsv_schp;
1139
1140         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1141                 return page;
1142         rsv_schp = &sfp->reserve;
1143         offset = addr - vma->vm_start;
1144         if (offset >= rsv_schp->bufflen)
1145                 return page;
1146         SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
1147                                    offset, rsv_schp->k_use_sg));
1148         if (rsv_schp->k_use_sg) {       /* reserve buffer is a scatter gather list */
1149                 int k;
1150                 unsigned long sa = vma->vm_start;
1151                 unsigned long len;
1152                 struct scatterlist *sclp = rsv_schp->buffer;
1153
1154                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1155                      ++k, ++sclp) {
1156                         len = vma->vm_end - sa;
1157                         len = (len < sclp->length) ? len : sclp->length;
1158                         if (offset < len) {
1159                                 page_ptr = sg_scatg2virt(sclp) + offset;
1160                                 page = virt_to_page(page_ptr);
1161                                 get_page(page); /* increment page count */
1162                                 break;
1163                         }
1164                         sa += len;
1165                         offset -= len;
1166                 }
1167         } else {                /* reserve buffer is just a single allocation */
1168                 page_ptr = (unsigned char *) rsv_schp->buffer + offset;
1169                 page = virt_to_page(page_ptr);
1170                 get_page(page); /* increment page count */
1171         }
1172         if (type)
1173                 *type = VM_FAULT_MINOR;
1174         return page;
1175 }
1176
1177 static struct vm_operations_struct sg_mmap_vm_ops = {
1178         .nopage = sg_vma_nopage,
1179 };
1180
1181 static int
1182 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1183 {
1184         Sg_fd *sfp;
1185         unsigned long req_sz = vma->vm_end - vma->vm_start;
1186         Sg_scatter_hold *rsv_schp;
1187
1188         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1189                 return -ENXIO;
1190         SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
1191                                    (void *) vma->vm_start, (int) req_sz));
1192         if (vma->vm_pgoff)
1193                 return -EINVAL; /* want no offset */
1194         rsv_schp = &sfp->reserve;
1195         if (req_sz > rsv_schp->bufflen)
1196                 return -ENOMEM; /* cannot map more than reserved buffer */
1197
1198         if (rsv_schp->k_use_sg) { /* reserve buffer is a scatter gather list */
1199                 int k;
1200                 unsigned long sa = vma->vm_start;
1201                 unsigned long len;
1202                 struct scatterlist *sclp = rsv_schp->buffer;
1203
1204                 for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
1205                      ++k, ++sclp) {
1206                         if (0 != sclp->offset)
1207                                 return -EFAULT; /* non page aligned memory ?? */
1208                         len = vma->vm_end - sa;
1209                         len = (len < sclp->length) ? len : sclp->length;
1210                         sa += len;
1211                 }
1212         } else {        /* reserve buffer is just a single allocation */
1213                 if ((unsigned long) rsv_schp->buffer & (PAGE_SIZE - 1))
1214                         return -EFAULT; /* non page aligned memory ?? */
1215         }
1216         if (0 == sfp->mmap_called) {
1217                 sg_rb_correct4mmap(rsv_schp, 1);        /* do only once per fd lifetime */
1218                 sfp->mmap_called = 1;
1219         }
1220         vma->vm_flags |= (VM_RESERVED | VM_IO);
1221         vma->vm_private_data = sfp;
1222         vma->vm_ops = &sg_mmap_vm_ops;
1223         return 0;
1224 }
1225
1226 /* This function is a "bottom half" handler that is called by the
1227  * mid level when a command is completed (or has failed). */
1228 static void
1229 sg_cmd_done(Scsi_Cmnd * SCpnt)
1230 {
1231         Scsi_Request *SRpnt = NULL;
1232         Sg_device *sdp = NULL;
1233         Sg_fd *sfp;
1234         Sg_request *srp = NULL;
1235
1236         if (SCpnt && (SRpnt = SCpnt->sc_request))
1237                 srp = (Sg_request *) SRpnt->upper_private_data;
1238         if (NULL == srp) {
1239                 printk(KERN_ERR "sg_cmd_done: NULL request\n");
1240                 if (SRpnt)
1241                         scsi_release_request(SRpnt);
1242                 return;
1243         }
1244         sfp = srp->parentfp;
1245         if (sfp)
1246                 sdp = sfp->parentdp;
1247         if ((NULL == sdp) || sdp->detached) {
1248                 printk(KERN_INFO "sg_cmd_done: device detached\n");
1249                 scsi_release_request(SRpnt);
1250                 return;
1251         }
1252
1253         /* First transfer ownership of data buffers to sg_device object. */
1254         srp->data.k_use_sg = SRpnt->sr_use_sg;
1255         srp->data.sglist_len = SRpnt->sr_sglist_len;
1256         srp->data.bufflen = SRpnt->sr_bufflen;
1257         srp->data.buffer = SRpnt->sr_buffer;
1258         /* now clear out request structure */
1259         SRpnt->sr_use_sg = 0;
1260         SRpnt->sr_sglist_len = 0;
1261         SRpnt->sr_bufflen = 0;
1262         SRpnt->sr_buffer = NULL;
1263         SRpnt->sr_underflow = 0;
1264         SRpnt->sr_request->rq_disk = NULL; /* "sg" _disowns_ request blk */
1265
1266         srp->my_cmdp = NULL;
1267
1268         SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
1269                 sdp->disk->disk_name, srp->header.pack_id, (int) SRpnt->sr_result));
1270         srp->header.resid = SCpnt->resid;
1271         /* N.B. unit of duration changes here from jiffies to millisecs */
1272         srp->header.duration =
1273             sg_jif_to_ms(jiffies - (int) srp->header.duration);
1274         if (0 != SRpnt->sr_result) {
1275                 memcpy(srp->sense_b, SRpnt->sr_sense_buffer,
1276                        sizeof (srp->sense_b));
1277                 srp->header.status = 0xff & SRpnt->sr_result;
1278                 srp->header.masked_status = status_byte(SRpnt->sr_result);
1279                 srp->header.msg_status = msg_byte(SRpnt->sr_result);
1280                 srp->header.host_status = host_byte(SRpnt->sr_result);
1281                 srp->header.driver_status = driver_byte(SRpnt->sr_result);
1282                 if ((sdp->sgdebug > 0) &&
1283                     ((CHECK_CONDITION == srp->header.masked_status) ||
1284                      (COMMAND_TERMINATED == srp->header.masked_status)))
1285                         print_req_sense("sg_cmd_done", SRpnt);
1286
1287                 /* Following if statement is a patch supplied by Eric Youngdale */
1288                 if (driver_byte(SRpnt->sr_result) != 0
1289                     && (SRpnt->sr_sense_buffer[0] & 0x7f) == 0x70
1290                     && (SRpnt->sr_sense_buffer[2] & 0xf) == UNIT_ATTENTION
1291                     && sdp->device->removable) {
1292                         /* Detected disc change. Set the bit - this may be used if */
1293                         /* there are filesystems using this device. */
1294                         sdp->device->changed = 1;
1295                 }
1296         }
1297         /* Rely on write phase to clean out srp status values, so no "else" */
1298
1299         scsi_release_request(SRpnt);
1300         SRpnt = NULL;
1301         if (sfp->closed) {      /* whoops this fd already released, cleanup */
1302                 SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
1303                 sg_finish_rem_req(srp);
1304                 srp = NULL;
1305                 if (NULL == sfp->headrp) {
1306                         SCSI_LOG_TIMEOUT(1, printk("sg...bh: already closed, final cleanup\n"));
1307                         if (0 == sg_remove_sfp(sdp, sfp)) {     /* device still present */
1308                                 scsi_device_put(sdp->device);
1309                         }
1310                         sfp = NULL;
1311                 }
1312         } else if (srp && srp->orphan) {
1313                 if (sfp->keep_orphan)
1314                         srp->sg_io_owned = 0;
1315                 else {
1316                         sg_finish_rem_req(srp);
1317                         srp = NULL;
1318                 }
1319         }
1320         if (sfp && srp) {
1321                 /* Now wake up any sg_read() that is waiting for this packet. */
1322                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1323                 srp->done = 1;
1324                 wake_up_interruptible(&sfp->read_wait);
1325         }
1326 }
1327
1328 static struct file_operations sg_fops = {
1329         .owner = THIS_MODULE,
1330         .read = sg_read,
1331         .write = sg_write,
1332         .poll = sg_poll,
1333         .ioctl = sg_ioctl,
1334         .open = sg_open,
1335         .mmap = sg_mmap,
1336         .release = sg_release,
1337         .fasync = sg_fasync,
1338 };
1339
1340 static struct class_simple * sg_sysfs_class;
1341
1342 static int sg_sysfs_valid = 0;
1343
1344 static int sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1345 {
1346         Sg_device *sdp;
1347         unsigned long iflags;
1348         void *old_sg_dev_arr = NULL;
1349         int k, error;
1350
1351         sdp = kmalloc(sizeof(Sg_device), GFP_KERNEL);
1352         if (!sdp) {
1353                 printk(KERN_WARNING "kmalloc Sg_device failure\n");
1354                 return -ENOMEM;
1355         }
1356
1357         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1358         if (unlikely(sg_nr_dev >= sg_dev_max)) {        /* try to resize */
1359                 Sg_device **tmp_da;
1360                 int tmp_dev_max = sg_nr_dev + SG_DEV_ARR_LUMP;
1361                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1362
1363                 tmp_da = kmalloc(tmp_dev_max * sizeof(Sg_device *), GFP_KERNEL);
1364                 if (unlikely(!tmp_da))
1365                         goto expand_failed;
1366
1367                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
1368                 memset(tmp_da, 0, tmp_dev_max * sizeof(Sg_device *));
1369                 memcpy(tmp_da, sg_dev_arr, sg_dev_max * sizeof(Sg_device *));
1370                 old_sg_dev_arr = sg_dev_arr;
1371                 sg_dev_arr = tmp_da;
1372                 sg_dev_max = tmp_dev_max;
1373         }
1374
1375         for (k = 0; k < sg_dev_max; k++)
1376                 if (!sg_dev_arr[k])
1377                         break;
1378         if (unlikely(k >= SG_MAX_DEVS))
1379                 goto overflow;
1380
1381         memset(sdp, 0, sizeof(*sdp));
1382         SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
1383         sprintf(disk->disk_name, "sg%d", k);
1384         disk->first_minor = k;
1385         sdp->disk = disk;
1386         sdp->device = scsidp;
1387         init_waitqueue_head(&sdp->o_excl_wait);
1388         sdp->sg_tablesize = scsidp->host ? scsidp->host->sg_tablesize : 0;
1389
1390         sg_nr_dev++;
1391         sg_dev_arr[k] = sdp;
1392         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1393         error = k;
1394
1395  out:
1396         if (error < 0)
1397                 kfree(sdp);
1398         kfree(old_sg_dev_arr);
1399         return error;
1400
1401  expand_failed:
1402         printk(KERN_WARNING "sg_alloc: device array cannot be resized\n");
1403         error = -ENOMEM;
1404         goto out;
1405
1406  overflow:
1407         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1408         printk(KERN_WARNING
1409                "Unable to attach sg device <%d, %d, %d, %d> type=%d, minor "
1410                "number exceeds %d\n", scsidp->host->host_no, scsidp->channel,
1411                scsidp->id, scsidp->lun, scsidp->type, SG_MAX_DEVS - 1);
1412         error = -ENODEV;
1413         goto out;
1414 }
1415
1416 static int
1417 sg_add(struct class_device *cl_dev)
1418 {
1419         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1420         struct gendisk *disk;
1421         Sg_device *sdp = NULL;
1422         struct cdev * cdev = NULL;
1423         int error, k;
1424
1425         disk = alloc_disk(1);
1426         if (!disk) {
1427                 printk(KERN_WARNING "alloc_disk failed\n");
1428                 return -ENOMEM;
1429         }
1430         disk->major = SCSI_GENERIC_MAJOR;
1431
1432         error = -ENOMEM;
1433         cdev = cdev_alloc();
1434         if (!cdev) {
1435                 printk(KERN_WARNING "cdev_alloc failed\n");
1436                 goto out;
1437         }
1438         cdev->owner = THIS_MODULE;
1439         cdev->ops = &sg_fops;
1440
1441         error = sg_alloc(disk, scsidp);
1442         if (error < 0) {
1443                 printk(KERN_WARNING "sg_alloc failed\n");
1444                 goto out;
1445         }
1446         k = error;
1447         sdp = sg_dev_arr[k];
1448
1449         devfs_mk_cdev(MKDEV(SCSI_GENERIC_MAJOR, k),
1450                         S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
1451                         "%s/generic", scsidp->devfs_name);
1452         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, k), 1);
1453         if (error) {
1454                 devfs_remove("%s/generic", scsidp->devfs_name);
1455                 goto out;
1456         }
1457         sdp->cdev = cdev;
1458         if (sg_sysfs_valid) {
1459                 struct class_device * sg_class_member;
1460
1461                 sg_class_member = class_simple_device_add(sg_sysfs_class,
1462                                 MKDEV(SCSI_GENERIC_MAJOR, k),
1463                                 cl_dev->dev, "%s",
1464                                 disk->disk_name);
1465                 if (IS_ERR(sg_class_member))
1466                         printk(KERN_WARNING "sg_add: "
1467                                 "class_simple_device_add failed\n");
1468                 class_set_devdata(sg_class_member, sdp);
1469                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1470                                           &sg_class_member->kobj, "generic");
1471                 if (error)
1472                         printk(KERN_ERR "sg_add: unable to make symlink "
1473                                         "'generic' back to sg%d\n", k);
1474         } else
1475                 printk(KERN_WARNING "sg_add: sg_sys INvalid\n");
1476
1477         printk(KERN_NOTICE
1478                "Attached scsi generic sg%d at scsi%d, channel"
1479                " %d, id %d, lun %d,  type %d\n", k,
1480                scsidp->host->host_no, scsidp->channel, scsidp->id,
1481                scsidp->lun, scsidp->type);
1482
1483         return 0;
1484
1485 out:
1486         put_disk(disk);
1487         if (cdev)
1488                 cdev_del(cdev);
1489         return error;
1490 }
1491
1492 static void
1493 sg_remove(struct class_device *cl_dev)
1494 {
1495         struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
1496         Sg_device *sdp = NULL;
1497         unsigned long iflags;
1498         Sg_fd *sfp;
1499         Sg_fd *tsfp;
1500         Sg_request *srp;
1501         Sg_request *tsrp;
1502         int k, delay;
1503
1504         if (NULL == sg_dev_arr)
1505                 return;
1506         delay = 0;
1507         write_lock_irqsave(&sg_dev_arr_lock, iflags);
1508         for (k = 0; k < sg_dev_max; k++) {
1509                 sdp = sg_dev_arr[k];
1510                 if ((NULL == sdp) || (sdp->device != scsidp))
1511                         continue;       /* dirty but lowers nesting */
1512                 if (sdp->headfp) {
1513                         sdp->detached = 1;
1514                         for (sfp = sdp->headfp; sfp; sfp = tsfp) {
1515                                 tsfp = sfp->nextfp;
1516                                 for (srp = sfp->headrp; srp; srp = tsrp) {
1517                                         tsrp = srp->nextrp;
1518                                         if (sfp->closed || (0 == srp->done))
1519                                                 sg_finish_rem_req(srp);
1520                                 }
1521                                 if (sfp->closed) {
1522                                         scsi_device_put(sdp->device);
1523                                         __sg_remove_sfp(sdp, sfp);
1524                                 } else {
1525                                         delay = 1;
1526                                         wake_up_interruptible(&sfp->read_wait);
1527                                         kill_fasync(&sfp->async_qp, SIGPOLL,
1528                                                     POLL_HUP);
1529                                 }
1530                         }
1531                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d, dirty\n", k));
1532                         if (NULL == sdp->headfp) {
1533                                 sg_dev_arr[k] = NULL;
1534                         }
1535                 } else {        /* nothing active, simple case */
1536                         SCSI_LOG_TIMEOUT(3, printk("sg_detach: dev=%d\n", k));
1537                         sg_dev_arr[k] = NULL;
1538                 }
1539                 sg_nr_dev--;
1540                 break;
1541         }
1542         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
1543
1544         if (sdp) {
1545                 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1546                 class_simple_device_remove(MKDEV(SCSI_GENERIC_MAJOR, k));
1547                 cdev_del(sdp->cdev);
1548                 sdp->cdev = NULL;
1549                 devfs_remove("%s/generic", scsidp->devfs_name);
1550                 put_disk(sdp->disk);
1551                 sdp->disk = NULL;
1552                 if (NULL == sdp->headfp)
1553                         kfree((char *) sdp);
1554         }
1555
1556         if (delay)
1557                 scsi_sleep(2);  /* dirty detach so delay device destruction */
1558 }
1559
1560 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
1561  * of sysfs parameters (which module_param doesn't yet support).
1562  * Sysfs parameters defined explicitly below.
1563  */
1564 module_param_named(def_reserved_size, def_reserved_size, int, 0);
1565 module_param_named(allow_dio, sg_allow_dio, int, 0);
1566
1567 MODULE_AUTHOR("Douglas Gilbert");
1568 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1569 MODULE_LICENSE("GPL");
1570 MODULE_VERSION(SG_VERSION_STR);
1571
1572 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1573 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1574
1575 static int __init
1576 init_sg(void)
1577 {
1578         int rc;
1579
1580         if (def_reserved_size >= 0)
1581                 sg_big_buff = def_reserved_size;
1582
1583         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1584                                     SG_MAX_DEVS, "sg");
1585         if (rc)
1586                 return rc;
1587         sg_sysfs_class = class_simple_create(THIS_MODULE, "scsi_generic");
1588         if ( IS_ERR(sg_sysfs_class) ) {
1589                 rc = PTR_ERR(sg_sysfs_class);
1590                 goto err_out;
1591         }
1592         sg_sysfs_valid = 1;
1593         rc = scsi_register_interface(&sg_interface);
1594         if (0 == rc) {
1595 #ifdef CONFIG_SCSI_PROC_FS
1596                 sg_proc_init();
1597 #endif                          /* CONFIG_SCSI_PROC_FS */
1598                 return 0;
1599         }
1600         class_simple_destroy(sg_sysfs_class);
1601 err_out:
1602         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1603         return rc;
1604 }
1605
1606 static void __exit
1607 exit_sg(void)
1608 {
1609 #ifdef CONFIG_SCSI_PROC_FS
1610         sg_proc_cleanup();
1611 #endif                          /* CONFIG_SCSI_PROC_FS */
1612         scsi_unregister_interface(&sg_interface);
1613         class_simple_destroy(sg_sysfs_class);
1614         sg_sysfs_valid = 0;
1615         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1616                                  SG_MAX_DEVS);
1617         if (sg_dev_arr != NULL) {
1618                 kfree((char *) sg_dev_arr);
1619                 sg_dev_arr = NULL;
1620         }
1621         sg_dev_max = 0;
1622 }
1623
1624 static int
1625 sg_start_req(Sg_request * srp)
1626 {
1627         int res;
1628         Sg_fd *sfp = srp->parentfp;
1629         sg_io_hdr_t *hp = &srp->header;
1630         int dxfer_len = (int) hp->dxfer_len;
1631         int dxfer_dir = hp->dxfer_direction;
1632         Sg_scatter_hold *req_schp = &srp->data;
1633         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1634
1635         SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
1636         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1637                 return 0;
1638         if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
1639             (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
1640             (!sfp->parentdp->device->host->unchecked_isa_dma)) {
1641                 res = sg_build_direct(srp, sfp, dxfer_len);
1642                 if (res <= 0)   /* -ve -> error, 0 -> done, 1 -> try indirect */
1643                         return res;
1644         }
1645         if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
1646                 sg_link_reserve(sfp, srp, dxfer_len);
1647         else {
1648                 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1649                 if (res) {
1650                         sg_remove_scat(req_schp);
1651                         return res;
1652                 }
1653         }
1654         return 0;
1655 }
1656
1657 static void
1658 sg_finish_rem_req(Sg_request * srp)
1659 {
1660         Sg_fd *sfp = srp->parentfp;
1661         Sg_scatter_hold *req_schp = &srp->data;
1662
1663         SCSI_LOG_TIMEOUT(4, printk("sg_finish_rem_req: res_used=%d\n", (int) srp->res_used));
1664         if (srp->res_used)
1665                 sg_unlink_reserve(sfp, srp);
1666         else
1667                 sg_remove_scat(req_schp);
1668         sg_remove_request(sfp, srp);
1669 }
1670
1671 static int
1672 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1673 {
1674         int ret_sz;
1675         int elem_sz = sizeof (struct scatterlist);
1676         int sg_bufflen = tablesize * elem_sz;
1677         int mx_sc_elems = tablesize;
1678
1679         schp->buffer = sg_page_malloc(sg_bufflen, sfp->low_dma, &ret_sz);
1680         if (!schp->buffer)
1681                 return -ENOMEM;
1682         else if (ret_sz != sg_bufflen) {
1683                 sg_bufflen = ret_sz;
1684                 mx_sc_elems = sg_bufflen / elem_sz;
1685         }
1686         schp->sglist_len = sg_bufflen;
1687         memset(schp->buffer, 0, sg_bufflen);
1688         return mx_sc_elems;     /* number of scat_gath elements allocated */
1689 }
1690
1691 #ifdef SG_ALLOW_DIO_CODE
1692 /* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
1693         /* hopefully this generic code will moved to a library */
1694
1695 /* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
1696    - mapping of all pages not successful
1697    - any page is above max_pfn
1698    (i.e., either completely successful or fails)
1699 */
1700 static int
1701 st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages,
1702                   unsigned long uaddr, size_t count, int rw,
1703                   unsigned long max_pfn)
1704 {
1705         int res, i, j;
1706         unsigned int nr_pages;
1707         struct page **pages;
1708
1709         nr_pages = ((uaddr & ~PAGE_MASK) + count + ~PAGE_MASK) >> PAGE_SHIFT;
1710
1711         /* User attempted Overflow! */
1712         if ((uaddr + count) < uaddr)
1713                 return -EINVAL;
1714
1715         /* Too big */
1716         if (nr_pages > max_pages)
1717                 return -ENOMEM;
1718
1719         /* Hmm? */
1720         if (count == 0)
1721                 return 0;
1722
1723         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
1724                 return -ENOMEM;
1725
1726         /* Try to fault in all of the necessary pages */
1727         down_read(&current->mm->mmap_sem);
1728         /* rw==READ means read from drive, write into memory area */
1729         res = get_user_pages(
1730                 current,
1731                 current->mm,
1732                 uaddr,
1733                 nr_pages,
1734                 rw == READ,
1735                 0, /* don't force */
1736                 pages,
1737                 NULL);
1738         up_read(&current->mm->mmap_sem);
1739
1740         /* Errors and no page mapped should return here */
1741         if (res < nr_pages)
1742                 goto out_unmap;
1743
1744         for (i=0; i < nr_pages; i++) {
1745                 /* FIXME: flush superflous for rw==READ,
1746                  * probably wrong function for rw==WRITE
1747                  */
1748                 flush_dcache_page(pages[i]);
1749                 if (page_to_pfn(pages[i]) > max_pfn)
1750                         goto out_unlock;
1751                 /* ?? Is locking needed? I don't think so */
1752                 /* if (TestSetPageLocked(pages[i]))
1753                    goto out_unlock; */
1754         }
1755
1756         /* Populate the scatter/gather list */
1757         sgl[0].page = pages[0];
1758         sgl[0].offset = uaddr & ~PAGE_MASK;
1759         if (nr_pages > 1) {
1760                 sgl[0].length = PAGE_SIZE - sgl[0].offset;
1761                 count -= sgl[0].length;
1762                 for (i=1; i < nr_pages ; i++) {
1763                         sgl[i].offset = 0;
1764                         sgl[i].page = pages[i];
1765                         sgl[i].length = count < PAGE_SIZE ? count : PAGE_SIZE;
1766                         count -= PAGE_SIZE;
1767                 }
1768         }
1769         else {
1770                 sgl[0].length = count;
1771         }
1772
1773         kfree(pages);
1774         return nr_pages;
1775
1776  out_unlock:
1777         /* for (j=0; j < i; j++)
1778            unlock_page(pages[j]); */
1779         res = 0;
1780  out_unmap:
1781         if (res > 0)
1782                 for (j=0; j < res; j++)
1783                         page_cache_release(pages[j]);
1784         kfree(pages);
1785         return res;
1786 }
1787
1788
1789 /* And unmap them... */
1790 static int
1791 st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
1792                     int dirtied)
1793 {
1794         int i;
1795
1796         for (i=0; i < nr_pages; i++) {
1797                 if (dirtied && !PageReserved(sgl[i].page))
1798                         SetPageDirty(sgl[i].page);
1799                 /* unlock_page(sgl[i].page); */
1800                 /* FIXME: cache flush missing for rw==READ
1801                  * FIXME: call the correct reference counting function
1802                  */
1803                 page_cache_release(sgl[i].page);
1804         }
1805
1806         return 0;
1807 }
1808
1809 /* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
1810 #endif
1811
1812
1813 /* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
1814 static int
1815 sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
1816 {
1817 #ifdef SG_ALLOW_DIO_CODE
1818         sg_io_hdr_t *hp = &srp->header;
1819         Sg_scatter_hold *schp = &srp->data;
1820         int sg_tablesize = sfp->parentdp->sg_tablesize;
1821         struct scatterlist *sgl;
1822         int mx_sc_elems, res;
1823         struct scsi_device *sdev = sfp->parentdp->device;
1824
1825         if (((unsigned long)hp->dxferp &
1826                         queue_dma_alignment(sdev->request_queue)) != 0)
1827                 return 1;
1828         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1829         if (mx_sc_elems <= 0) {
1830                 return 1;
1831         }
1832         sgl = (struct scatterlist *)schp->buffer;
1833         res = st_map_user_pages(sgl, mx_sc_elems, (unsigned long)hp->dxferp, dxfer_len,
1834                                 (SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0, ULONG_MAX);
1835         if (res <= 0)
1836                 return 1;
1837         schp->k_use_sg = res;
1838         schp->dio_in_use = 1;
1839         hp->info |= SG_INFO_DIRECT_IO;
1840         return 0;
1841 #else
1842         return 1;
1843 #endif
1844 }
1845
1846 static int
1847 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1848 {
1849         int ret_sz;
1850         int blk_size = buff_size;
1851         unsigned char *p = NULL;
1852
1853         if ((blk_size < 0) || (!sfp))
1854                 return -EFAULT;
1855         if (0 == blk_size)
1856                 ++blk_size;     /* don't know why */
1857 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1858         blk_size = (blk_size + SG_SECTOR_MSK) & (~SG_SECTOR_MSK);
1859         SCSI_LOG_TIMEOUT(4, printk("sg_build_indirect: buff_size=%d, blk_size=%d\n",
1860                                    buff_size, blk_size));
1861         if (blk_size <= SG_SCATTER_SZ) {
1862                 p = sg_page_malloc(blk_size, sfp->low_dma, &ret_sz);
1863                 if (!p)
1864                         return -ENOMEM;
1865                 if (blk_size == ret_sz) {       /* got it on the first attempt */
1866                         schp->k_use_sg = 0;
1867                         schp->buffer = p;
1868                         schp->bufflen = blk_size;
1869                         schp->b_malloc_len = blk_size;
1870                         return 0;
1871                 }
1872         } else {
1873                 p = sg_page_malloc(SG_SCATTER_SZ, sfp->low_dma, &ret_sz);
1874                 if (!p)
1875                         return -ENOMEM;
1876         }
1877 /* Want some local declarations, so start new block ... */
1878         {                       /* lets try and build a scatter gather list */
1879                 struct scatterlist *sclp;
1880                 int k, rem_sz, num;
1881                 int mx_sc_elems;
1882                 int sg_tablesize = sfp->parentdp->sg_tablesize;
1883                 int first = 1;
1884
1885                 /* N.B. ret_sz carried into this block ... */
1886                 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1887                 if (mx_sc_elems < 0)
1888                         return mx_sc_elems;     /* most likely -ENOMEM */
1889
1890                 for (k = 0, sclp = schp->buffer, rem_sz = blk_size;
1891                      (rem_sz > 0) && (k < mx_sc_elems);
1892                      ++k, rem_sz -= ret_sz, ++sclp) {
1893                         if (first)
1894                                 first = 0;
1895                         else {
1896                                 num =
1897                                     (rem_sz >
1898                                      SG_SCATTER_SZ) ? SG_SCATTER_SZ : rem_sz;
1899                                 p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
1900                                 if (!p)
1901                                         break;
1902                         }
1903                         sclp->page = virt_to_page(p);
1904                         sclp->offset = offset_in_page(p);
1905                         sclp->length = ret_sz;
1906
1907                         SCSI_LOG_TIMEOUT(5, printk("sg_build_build: k=%d, a=0x%p, len=%d\n",
1908                                           k, sg_scatg2virt(sclp), ret_sz));
1909                 }               /* end of for loop */
1910                 schp->k_use_sg = k;
1911                 SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, rem_sz=%d\n", k, rem_sz));
1912                 schp->bufflen = blk_size;
1913                 if (rem_sz > 0) /* must have failed */
1914                         return -ENOMEM;
1915         }
1916         return 0;
1917 }
1918
1919 static int
1920 sg_write_xfer(Sg_request * srp)
1921 {
1922         sg_io_hdr_t *hp = &srp->header;
1923         Sg_scatter_hold *schp = &srp->data;
1924         int num_xfer = 0;
1925         int j, k, onum, usglen, ksglen, res;
1926         int iovec_count = (int) hp->iovec_count;
1927         int dxfer_dir = hp->dxfer_direction;
1928         unsigned char *p;
1929         unsigned char __user *up;
1930         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
1931
1932         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
1933             (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
1934                 num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
1935                 if (schp->bufflen < num_xfer)
1936                         num_xfer = schp->bufflen;
1937         }
1938         if ((num_xfer <= 0) || (schp->dio_in_use) ||
1939             (new_interface
1940              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
1941                 return 0;
1942
1943         SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
1944                           num_xfer, iovec_count, schp->k_use_sg));
1945         if (iovec_count) {
1946                 onum = iovec_count;
1947                 if ((k = verify_area(VERIFY_READ, hp->dxferp,
1948                                      SZ_SG_IOVEC * onum)))
1949                         return k;
1950         } else
1951                 onum = 1;
1952
1953         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
1954                 for (j = 0, p = schp->buffer; j < onum; ++j) {
1955                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1956                         if (res)
1957                                 return res;
1958                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
1959                         if (__copy_from_user(p, up, usglen))
1960                                 return -EFAULT;
1961                         p += usglen;
1962                         num_xfer -= usglen;
1963                         if (num_xfer <= 0)
1964                                 return 0;
1965                 }
1966         } else {                /* kernel using scatter gather list */
1967                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
1968
1969                 ksglen = (int) sclp->length;
1970                 p = sg_scatg2virt(sclp);
1971                 for (j = 0, k = 0; j < onum; ++j) {
1972                         res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
1973                         if (res)
1974                                 return res;
1975
1976                         for (; p; ++sclp, ksglen = (int) sclp->length,
1977                                   p = sg_scatg2virt(sclp)) {
1978                                 if (usglen <= 0)
1979                                         break;
1980                                 if (ksglen > usglen) {
1981                                         if (usglen >= num_xfer) {
1982                                                 if (__copy_from_user
1983                                                     (p, up, num_xfer))
1984                                                         return -EFAULT;
1985                                                 return 0;
1986                                         }
1987                                         if (__copy_from_user(p, up, usglen))
1988                                                 return -EFAULT;
1989                                         p += usglen;
1990                                         ksglen -= usglen;
1991                                         break;
1992                                 } else {
1993                                         if (ksglen >= num_xfer) {
1994                                                 if (__copy_from_user
1995                                                     (p, up, num_xfer))
1996                                                         return -EFAULT;
1997                                                 return 0;
1998                                         }
1999                                         if (__copy_from_user(p, up, ksglen))
2000                                                 return -EFAULT;
2001                                         up += ksglen;
2002                                         usglen -= ksglen;
2003                                 }
2004                                 ++k;
2005                                 if (k >= schp->k_use_sg)
2006                                         return 0;
2007                         }
2008                 }
2009         }
2010         return 0;
2011 }
2012
2013 static int
2014 sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
2015            int wr_xf, int *countp, unsigned char __user **up)
2016 {
2017         int num_xfer = (int) hp->dxfer_len;
2018         unsigned char __user *p = hp->dxferp;
2019         int count, k;
2020
2021         if (0 == sg_num) {
2022                 if (wr_xf && ('\0' == hp->interface_id))
2023                         count = (int) hp->flags;        /* holds "old" input_size */
2024                 else
2025                         count = num_xfer;
2026         } else {
2027                 sg_iovec_t iovec;
2028                 if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
2029                         return -EFAULT;
2030                 p = iovec.iov_base;
2031                 count = (int) iovec.iov_len;
2032         }
2033         if ((k = verify_area(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count)))
2034                 return k;
2035         if (up)
2036                 *up = p;
2037         if (countp)
2038                 *countp = count;
2039         return 0;
2040 }
2041
2042 static void
2043 sg_remove_scat(Sg_scatter_hold * schp)
2044 {
2045         SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
2046         if (schp->buffer && (schp->sglist_len > 0)) {
2047                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2048
2049                 if (schp->dio_in_use) {
2050 #ifdef SG_ALLOW_DIO_CODE
2051                         st_unmap_user_pages(sclp, schp->k_use_sg, TRUE);
2052 #endif
2053                 } else {
2054                         int k;
2055
2056                         for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2057                              ++k, ++sclp) {
2058                                 SCSI_LOG_TIMEOUT(5, printk(
2059                                     "sg_remove_scat: k=%d, a=0x%p, len=%d\n",
2060                                     k, sg_scatg2virt(sclp), sclp->length));
2061                                 sg_page_free(sg_scatg2virt(sclp), sclp->length);
2062                                 sclp->page = NULL;
2063                                 sclp->offset = 0;
2064                                 sclp->length = 0;
2065                         }
2066                 }
2067                 sg_page_free(schp->buffer, schp->sglist_len);
2068         } else if (schp->buffer)
2069                 sg_page_free(schp->buffer, schp->b_malloc_len);
2070         memset(schp, 0, sizeof (*schp));
2071 }
2072
2073 static int
2074 sg_read_xfer(Sg_request * srp)
2075 {
2076         sg_io_hdr_t *hp = &srp->header;
2077         Sg_scatter_hold *schp = &srp->data;
2078         int num_xfer = 0;
2079         int j, k, onum, usglen, ksglen, res;
2080         int iovec_count = (int) hp->iovec_count;
2081         int dxfer_dir = hp->dxfer_direction;
2082         unsigned char *p;
2083         unsigned char __user *up;
2084         int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
2085
2086         if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
2087             || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
2088                 num_xfer = hp->dxfer_len;
2089                 if (schp->bufflen < num_xfer)
2090                         num_xfer = schp->bufflen;
2091         }
2092         if ((num_xfer <= 0) || (schp->dio_in_use) ||
2093             (new_interface
2094              && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
2095                 return 0;
2096
2097         SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
2098                           num_xfer, iovec_count, schp->k_use_sg));
2099         if (iovec_count) {
2100                 onum = iovec_count;
2101                 if ((k = verify_area(VERIFY_READ, hp->dxferp,
2102                                      SZ_SG_IOVEC * onum)))
2103                         return k;
2104         } else
2105                 onum = 1;
2106
2107         if (0 == schp->k_use_sg) {      /* kernel has single buffer */
2108                 for (j = 0, p = schp->buffer; j < onum; ++j) {
2109                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2110                         if (res)
2111                                 return res;
2112                         usglen = (num_xfer > usglen) ? usglen : num_xfer;
2113                         if (__copy_to_user(up, p, usglen))
2114                                 return -EFAULT;
2115                         p += usglen;
2116                         num_xfer -= usglen;
2117                         if (num_xfer <= 0)
2118                                 return 0;
2119                 }
2120         } else {                /* kernel using scatter gather list */
2121                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2122
2123                 ksglen = (int) sclp->length;
2124                 p = sg_scatg2virt(sclp);
2125                 for (j = 0, k = 0; j < onum; ++j) {
2126                         res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
2127                         if (res)
2128                                 return res;
2129
2130                         for (; p; ++sclp, ksglen = (int) sclp->length,
2131                                   p = sg_scatg2virt(sclp)) {
2132                                 if (usglen <= 0)
2133                                         break;
2134                                 if (ksglen > usglen) {
2135                                         if (usglen >= num_xfer) {
2136                                                 if (__copy_to_user
2137                                                     (up, p, num_xfer))
2138                                                         return -EFAULT;
2139                                                 return 0;
2140                                         }
2141                                         if (__copy_to_user(up, p, usglen))
2142                                                 return -EFAULT;
2143                                         p += usglen;
2144                                         ksglen -= usglen;
2145                                         break;
2146                                 } else {
2147                                         if (ksglen >= num_xfer) {
2148                                                 if (__copy_to_user
2149                                                     (up, p, num_xfer))
2150                                                         return -EFAULT;
2151                                                 return 0;
2152                                         }
2153                                         if (__copy_to_user(up, p, ksglen))
2154                                                 return -EFAULT;
2155                                         up += ksglen;
2156                                         usglen -= ksglen;
2157                                 }
2158                                 ++k;
2159                                 if (k >= schp->k_use_sg)
2160                                         return 0;
2161                         }
2162                 }
2163         }
2164         return 0;
2165 }
2166
2167 static int
2168 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
2169 {
2170         Sg_scatter_hold *schp = &srp->data;
2171
2172         SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
2173                                    num_read_xfer));
2174         if ((!outp) || (num_read_xfer <= 0))
2175                 return 0;
2176         if (schp->k_use_sg > 0) {
2177                 int k, num;
2178                 struct scatterlist *sclp = (struct scatterlist *) schp->buffer;
2179
2180                 for (k = 0; (k < schp->k_use_sg) && sg_scatg2virt(sclp);
2181                      ++k, ++sclp) {
2182                         num = (int) sclp->length;
2183                         if (num > num_read_xfer) {
2184                                 if (__copy_to_user
2185                                     (outp, sg_scatg2virt(sclp), num_read_xfer))
2186                                         return -EFAULT;
2187                                 break;
2188                         } else {
2189                                 if (__copy_to_user
2190                                     (outp, sg_scatg2virt(sclp), num))
2191                                         return -EFAULT;
2192                                 num_read_xfer -= num;
2193                                 if (num_read_xfer <= 0)
2194                                         break;
2195                                 outp += num;
2196                         }
2197                 }
2198         } else {
2199                 if (__copy_to_user(outp, schp->buffer, num_read_xfer))
2200                         return -EFAULT;
2201         }
2202         return 0;
2203 }
2204
2205 static void
2206 sg_build_reserve(Sg_fd * sfp, int req_size)
2207 {
2208         Sg_scatter_hold *schp = &sfp->reserve;
2209
2210         SCSI_LOG_TIMEOUT(4, printk("sg_build_reserve: req_size=%d\n", req_size));
2211         do {
2212                 if (req_size < PAGE_SIZE)
2213                         req_size = PAGE_SIZE;
2214                 if (0 == sg_build_indirect(schp, sfp, req_size))
2215                         return;
2216                 else
2217                         sg_remove_scat(schp);
2218                 req_size >>= 1; /* divide by 2 */
2219         } while (req_size > (PAGE_SIZE / 2));
2220 }
2221
2222 static void
2223 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2224 {
2225         Sg_scatter_hold *req_schp = &srp->data;
2226         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2227
2228         srp->res_used = 1;
2229         SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
2230         size = (size + 1) & (~1);       /* round to even for aha1542 */
2231         if (rsv_schp->k_use_sg > 0) {
2232                 int k, num;
2233                 int rem = size;
2234                 struct scatterlist *sclp =
2235                     (struct scatterlist *) rsv_schp->buffer;
2236
2237                 for (k = 0; k < rsv_schp->k_use_sg; ++k, ++sclp) {
2238                         num = (int) sclp->length;
2239                         if (rem <= num) {
2240                                 if (0 == k) {
2241                                         req_schp->k_use_sg = 0;
2242                                         req_schp->buffer = sg_scatg2virt(sclp);
2243                                 } else {
2244                                         sfp->save_scat_len = num;
2245                                         sclp->length = (unsigned) rem;
2246                                         req_schp->k_use_sg = k + 1;
2247                                         req_schp->sglist_len =
2248                                             rsv_schp->sglist_len;
2249                                         req_schp->buffer = rsv_schp->buffer;
2250                                 }
2251                                 req_schp->bufflen = size;
2252                                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2253                                 break;
2254                         } else
2255                                 rem -= num;
2256                 }
2257                 if (k >= rsv_schp->k_use_sg)
2258                         SCSI_LOG_TIMEOUT(1, printk("sg_link_reserve: BAD size\n"));
2259         } else {
2260                 req_schp->k_use_sg = 0;
2261                 req_schp->bufflen = size;
2262                 req_schp->buffer = rsv_schp->buffer;
2263                 req_schp->b_malloc_len = rsv_schp->b_malloc_len;
2264         }
2265 }
2266
2267 static void
2268 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2269 {
2270         Sg_scatter_hold *req_schp = &srp->data;
2271         Sg_scatter_hold *rsv_schp = &sfp->reserve;
2272
2273         SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
2274                                    (int) req_schp->k_use_sg));
2275         if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
2276                 struct scatterlist *sclp =
2277                     (struct scatterlist *) rsv_schp->buffer;
2278
2279                 if (sfp->save_scat_len > 0)
2280                         (sclp + (req_schp->k_use_sg - 1))->length =
2281                             (unsigned) sfp->save_scat_len;
2282                 else
2283                         SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
2284         }
2285         req_schp->k_use_sg = 0;
2286         req_schp->bufflen = 0;
2287         req_schp->buffer = NULL;
2288         req_schp->sglist_len = 0;
2289         sfp->save_scat_len = 0;
2290         srp->res_used = 0;
2291 }
2292
2293 static Sg_request *
2294 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2295 {
2296         Sg_request *resp;
2297         unsigned long iflags;
2298
2299         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2300         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2301                 /* look for requests that are ready + not SG_IO owned */
2302                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2303                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2304                         resp->done = 2; /* guard against other readers */
2305                         break;
2306                 }
2307         }
2308         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2309         return resp;
2310 }
2311
2312 #ifdef CONFIG_SCSI_PROC_FS
2313 static Sg_request *
2314 sg_get_nth_request(Sg_fd * sfp, int nth)
2315 {
2316         Sg_request *resp;
2317         unsigned long iflags;
2318         int k;
2319
2320         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2321         for (k = 0, resp = sfp->headrp; resp && (k < nth);
2322              ++k, resp = resp->nextrp) ;
2323         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2324         return resp;
2325 }
2326 #endif
2327
2328 /* always adds to end of list */
2329 static Sg_request *
2330 sg_add_request(Sg_fd * sfp)
2331 {
2332         int k;
2333         unsigned long iflags;
2334         Sg_request *resp;
2335         Sg_request *rp = sfp->req_arr;
2336
2337         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2338         resp = sfp->headrp;
2339         if (!resp) {
2340                 memset(rp, 0, sizeof (Sg_request));
2341                 rp->parentfp = sfp;
2342                 resp = rp;
2343                 sfp->headrp = resp;
2344         } else {
2345                 if (0 == sfp->cmd_q)
2346                         resp = NULL;    /* command queuing disallowed */
2347                 else {
2348                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2349                                 if (!rp->parentfp)
2350                                         break;
2351                         }
2352                         if (k < SG_MAX_QUEUE) {
2353                                 memset(rp, 0, sizeof (Sg_request));
2354                                 rp->parentfp = sfp;
2355                                 while (resp->nextrp)
2356                                         resp = resp->nextrp;
2357                                 resp->nextrp = rp;
2358                                 resp = rp;
2359                         } else
2360                                 resp = NULL;
2361                 }
2362         }
2363         if (resp) {
2364                 resp->nextrp = NULL;
2365                 resp->header.duration = jiffies;
2366                 resp->my_cmdp = NULL;
2367         }
2368         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2369         return resp;
2370 }
2371
2372 /* Return of 1 for found; 0 for not found */
2373 static int
2374 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2375 {
2376         Sg_request *prev_rp;
2377         Sg_request *rp;
2378         unsigned long iflags;
2379         int res = 0;
2380
2381         if ((!sfp) || (!srp) || (!sfp->headrp))
2382                 return res;
2383         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2384         prev_rp = sfp->headrp;
2385         if (srp == prev_rp) {
2386                 sfp->headrp = prev_rp->nextrp;
2387                 prev_rp->parentfp = NULL;
2388                 res = 1;
2389         } else {
2390                 while ((rp = prev_rp->nextrp)) {
2391                         if (srp == rp) {
2392                                 prev_rp->nextrp = rp->nextrp;
2393                                 rp->parentfp = NULL;
2394                                 res = 1;
2395                                 break;
2396                         }
2397                         prev_rp = rp;
2398                 }
2399         }
2400         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2401         return res;
2402 }
2403
2404 #ifdef CONFIG_SCSI_PROC_FS
2405 static Sg_fd *
2406 sg_get_nth_sfp(Sg_device * sdp, int nth)
2407 {
2408         Sg_fd *resp;
2409         unsigned long iflags;
2410         int k;
2411
2412         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2413         for (k = 0, resp = sdp->headfp; resp && (k < nth);
2414              ++k, resp = resp->nextfp) ;
2415         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2416         return resp;
2417 }
2418 #endif
2419
2420 static Sg_fd *
2421 sg_add_sfp(Sg_device * sdp, int dev)
2422 {
2423         Sg_fd *sfp;
2424         unsigned long iflags;
2425
2426         sfp = (Sg_fd *) sg_page_malloc(sizeof (Sg_fd), 0, NULL);
2427         if (!sfp)
2428                 return NULL;
2429         memset(sfp, 0, sizeof (Sg_fd));
2430         init_waitqueue_head(&sfp->read_wait);
2431         sfp->rq_list_lock = RW_LOCK_UNLOCKED;
2432
2433         sfp->timeout = SG_DEFAULT_TIMEOUT;
2434         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2435         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2436         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2437             sdp->device->host->unchecked_isa_dma : 1;
2438         sfp->cmd_q = SG_DEF_COMMAND_Q;
2439         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2440         sfp->parentdp = sdp;
2441         write_lock_irqsave(&sg_dev_arr_lock, iflags);
2442         if (!sdp->headfp)
2443                 sdp->headfp = sfp;
2444         else {                  /* add to tail of existing list */
2445                 Sg_fd *pfp = sdp->headfp;
2446                 while (pfp->nextfp)
2447                         pfp = pfp->nextfp;
2448                 pfp->nextfp = sfp;
2449         }
2450         write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2451         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp));
2452         sg_build_reserve(sfp, sg_big_buff);
2453         SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp:   bufflen=%d, k_use_sg=%d\n",
2454                            sfp->reserve.bufflen, sfp->reserve.k_use_sg));
2455         return sfp;
2456 }
2457
2458 static void
2459 __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2460 {
2461         Sg_fd *fp;
2462         Sg_fd *prev_fp;
2463
2464         prev_fp = sdp->headfp;
2465         if (sfp == prev_fp)
2466                 sdp->headfp = prev_fp->nextfp;
2467         else {
2468                 while ((fp = prev_fp->nextfp)) {
2469                         if (sfp == fp) {
2470                                 prev_fp->nextfp = fp->nextfp;
2471                                 break;
2472                         }
2473                         prev_fp = fp;
2474                 }
2475         }
2476         if (sfp->reserve.bufflen > 0) {
2477                 SCSI_LOG_TIMEOUT(6,
2478                         printk("__sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2479                         (int) sfp->reserve.bufflen, (int) sfp->reserve.k_use_sg));
2480                 if (sfp->mmap_called)
2481                         sg_rb_correct4mmap(&sfp->reserve, 0);   /* undo correction */
2482                 sg_remove_scat(&sfp->reserve);
2483         }
2484         sfp->parentdp = NULL;
2485         SCSI_LOG_TIMEOUT(6, printk("__sg_remove_sfp:    sfp=0x%p\n", sfp));
2486         sg_page_free((char *) sfp, sizeof (Sg_fd));
2487 }
2488
2489 /* Returns 0 in normal case, 1 when detached and sdp object removed */
2490 static int
2491 sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp)
2492 {
2493         Sg_request *srp;
2494         Sg_request *tsrp;
2495         int dirty = 0;
2496         int res = 0;
2497
2498         for (srp = sfp->headrp; srp; srp = tsrp) {
2499                 tsrp = srp->nextrp;
2500                 if (srp->done)
2501                         sg_finish_rem_req(srp);
2502                 else
2503                         ++dirty;
2504         }
2505         if (0 == dirty) {
2506                 unsigned long iflags;
2507
2508                 write_lock_irqsave(&sg_dev_arr_lock, iflags);
2509                 __sg_remove_sfp(sdp, sfp);
2510                 if (sdp->detached && (NULL == sdp->headfp)) {
2511                         int k, maxd;
2512
2513                         maxd = sg_dev_max;
2514                         for (k = 0; k < maxd; ++k) {
2515                                 if (sdp == sg_dev_arr[k])
2516                                         break;
2517                         }
2518                         if (k < maxd)
2519                                 sg_dev_arr[k] = NULL;
2520                         kfree((char *) sdp);
2521                         res = 1;
2522                 }
2523                 write_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2524         } else {
2525                 /* MOD_INC's to inhibit unloading sg and associated adapter driver */
2526                 /* only bump the access_count if we actually succeeded in
2527                  * throwing another counter on the host module */
2528                 scsi_device_get(sdp->device);   /* XXX: retval ignored? */
2529                 sfp->closed = 1;        /* flag dirty state on this fd */
2530                 SCSI_LOG_TIMEOUT(1, printk("sg_remove_sfp: worrisome, %d writes pending\n",
2531                                   dirty));
2532         }
2533         return res;
2534 }
2535
2536 static int
2537 sg_res_in_use(Sg_fd * sfp)
2538 {
2539         const Sg_request *srp;
2540         unsigned long iflags;
2541
2542         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2543         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2544                 if (srp->res_used)
2545                         break;
2546         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2547         return srp ? 1 : 0;
2548 }
2549
2550 /* If retSzp==NULL want exact size or fail */
2551 static char *
2552 sg_page_malloc(int rqSz, int lowDma, int *retSzp)
2553 {
2554         char *resp = NULL;
2555         int page_mask;
2556         int order, a_size;
2557         int resSz = rqSz;
2558
2559         if (rqSz <= 0)
2560                 return resp;
2561
2562         if (lowDma)
2563                 page_mask = GFP_ATOMIC | GFP_DMA | __GFP_NOWARN;
2564         else
2565                 page_mask = GFP_ATOMIC | __GFP_NOWARN;
2566
2567         for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
2568              order++, a_size <<= 1) ;
2569         resp = (char *) __get_free_pages(page_mask, order);
2570         while ((!resp) && order && retSzp) {
2571                 --order;
2572                 a_size >>= 1;   /* divide by 2, until PAGE_SIZE */
2573                 resp = (char *) __get_free_pages(page_mask, order);     /* try half */
2574                 resSz = a_size;
2575         }
2576         if (resp) {
2577                 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2578                         memset(resp, 0, resSz);
2579                 if (retSzp)
2580                         *retSzp = resSz;
2581         }
2582         return resp;
2583 }
2584
2585 static void
2586 sg_page_free(char *buff, int size)
2587 {
2588         int order, a_size;
2589
2590         if (!buff)
2591                 return;
2592         for (order = 0, a_size = PAGE_SIZE; a_size < size;
2593              order++, a_size <<= 1) ;
2594         free_pages((unsigned long) buff, order);
2595 }
2596
2597 static int
2598 sg_ms_to_jif(unsigned int msecs)
2599 {
2600         if ((UINT_MAX / 2U) < msecs)
2601                 return INT_MAX; /* special case, set largest possible */
2602         else
2603                 return ((int) msecs <
2604                         (INT_MAX / 1000)) ? (((int) msecs * HZ) / 1000)
2605                     : (((int) msecs / 1000) * HZ);
2606 }
2607
2608 static unsigned char allow_ops[] = { TEST_UNIT_READY, REQUEST_SENSE,
2609         INQUIRY, READ_CAPACITY, READ_BUFFER, READ_6, READ_10, READ_12,
2610         MODE_SENSE, MODE_SENSE_10, LOG_SENSE
2611 };
2612
2613 static int
2614 sg_allow_access(unsigned char opcode, char dev_type)
2615 {
2616         int k;
2617
2618         if (TYPE_SCANNER == dev_type)   /* TYPE_ROM maybe burner */
2619                 return 1;
2620         for (k = 0; k < sizeof (allow_ops); ++k) {
2621                 if (opcode == allow_ops[k])
2622                         return 1;
2623         }
2624         return 0;
2625 }
2626
2627 #ifdef CONFIG_SCSI_PROC_FS
2628 static int
2629 sg_last_dev(void)
2630 {
2631         int k;
2632         unsigned long iflags;
2633
2634         read_lock_irqsave(&sg_dev_arr_lock, iflags);
2635         for (k = sg_dev_max - 1; k >= 0; --k)
2636                 if (sg_dev_arr[k] && sg_dev_arr[k]->device)
2637                         break;
2638         read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2639         return k + 1;           /* origin 1 */
2640 }
2641 #endif
2642
2643 static Sg_device *
2644 sg_get_dev(int dev)
2645 {
2646         Sg_device *sdp = NULL;
2647         unsigned long iflags;
2648
2649         if (sg_dev_arr && (dev >= 0)) {
2650                 read_lock_irqsave(&sg_dev_arr_lock, iflags);
2651                 if (dev < sg_dev_max)
2652                         sdp = sg_dev_arr[dev];
2653                 read_unlock_irqrestore(&sg_dev_arr_lock, iflags);
2654         }
2655         return sdp;
2656 }
2657
2658 #ifdef CONFIG_SCSI_PROC_FS
2659
2660 static struct proc_dir_entry *sg_proc_sgp = NULL;
2661
2662 static char sg_proc_sg_dirname[] = "scsi/sg";
2663
2664 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2665
2666 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2667 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2668                                   size_t count, loff_t *off);
2669 static struct file_operations adio_fops = {
2670         /* .owner, .read and .llseek added in sg_proc_init() */
2671         .open = sg_proc_single_open_adio,
2672         .write = sg_proc_write_adio,
2673         .release = single_release,
2674 };
2675
2676 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2677 static ssize_t sg_proc_write_dressz(struct file *filp,
2678                 const char __user *buffer, size_t count, loff_t *off);
2679 static struct file_operations dressz_fops = {
2680         .open = sg_proc_single_open_dressz,
2681         .write = sg_proc_write_dressz,
2682         .release = single_release,
2683 };
2684
2685 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2686 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2687 static struct file_operations version_fops = {
2688         .open = sg_proc_single_open_version,
2689         .release = single_release,
2690 };
2691
2692 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2693 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2694 static struct file_operations devhdr_fops = {
2695         .open = sg_proc_single_open_devhdr,
2696         .release = single_release,
2697 };
2698
2699 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2700 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2701 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2702 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2703 static void dev_seq_stop(struct seq_file *s, void *v);
2704 static struct file_operations dev_fops = {
2705         .open = sg_proc_open_dev,
2706         .release = seq_release,
2707 };
2708 static struct seq_operations dev_seq_ops = {
2709         .start = dev_seq_start,
2710         .next  = dev_seq_next,
2711         .stop  = dev_seq_stop,
2712         .show  = sg_proc_seq_show_dev,
2713 };
2714
2715 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2716 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2717 static struct file_operations devstrs_fops = {
2718         .open = sg_proc_open_devstrs,
2719         .release = seq_release,
2720 };
2721 static struct seq_operations devstrs_seq_ops = {
2722         .start = dev_seq_start,
2723         .next  = dev_seq_next,
2724         .stop  = dev_seq_stop,
2725         .show  = sg_proc_seq_show_devstrs,
2726 };
2727
2728 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2729 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2730 static struct file_operations debug_fops = {
2731         .open = sg_proc_open_debug,
2732         .release = seq_release,
2733 };
2734 static struct seq_operations debug_seq_ops = {
2735         .start = dev_seq_start,
2736         .next  = dev_seq_next,
2737         .stop  = dev_seq_stop,
2738         .show  = sg_proc_seq_show_debug,
2739 };
2740
2741
2742 struct sg_proc_leaf {
2743         const char * name;
2744         struct file_operations * fops;
2745 };
2746
2747 static struct sg_proc_leaf sg_proc_leaf_arr[] = {
2748         {"allow_dio", &adio_fops},
2749         {"debug", &debug_fops},
2750         {"def_reserved_size", &dressz_fops},
2751         {"device_hdr", &devhdr_fops},
2752         {"devices", &dev_fops},
2753         {"device_strs", &devstrs_fops},
2754         {"version", &version_fops}
2755 };
2756
2757 static int
2758 sg_proc_init(void)
2759 {
2760         int k, mask;
2761         int num_leaves =
2762             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2763         struct proc_dir_entry *pdep;
2764         struct sg_proc_leaf * leaf;
2765
2766         sg_proc_sgp = create_proc_entry(sg_proc_sg_dirname,
2767                                         S_IFDIR | S_IRUGO | S_IXUGO, NULL);
2768         if (!sg_proc_sgp)
2769                 return 1;
2770         for (k = 0; k < num_leaves; ++k) {
2771                 leaf = &sg_proc_leaf_arr[k];
2772                 mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2773                 pdep = create_proc_entry(leaf->name, mask, sg_proc_sgp);
2774                 if (pdep) {
2775                         leaf->fops->owner = THIS_MODULE,
2776                         leaf->fops->read = seq_read,
2777                         leaf->fops->llseek = seq_lseek,
2778                         pdep->proc_fops = leaf->fops;
2779                 }
2780         }
2781         return 0;
2782 }
2783
2784 static void
2785 sg_proc_cleanup(void)
2786 {
2787         int k;
2788         int num_leaves =
2789             sizeof (sg_proc_leaf_arr) / sizeof (sg_proc_leaf_arr[0]);
2790
2791         if (!sg_proc_sgp)
2792                 return;
2793         for (k = 0; k < num_leaves; ++k)
2794                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2795         remove_proc_entry(sg_proc_sg_dirname, NULL);
2796 }
2797
2798
2799 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2800 {
2801         seq_printf(s, "%d\n", *((int *)s->private));
2802         return 0;
2803 }
2804
2805 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2806 {
2807         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2808 }
2809
2810 static ssize_t
2811 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2812                    size_t count, loff_t *off)
2813 {
2814         int num;
2815         char buff[11];
2816
2817         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2818                 return -EACCES;
2819         num = (count < 10) ? count : 10;
2820         if (copy_from_user(buff, buffer, num))
2821                 return -EFAULT;
2822         buff[num] = '\0';
2823         sg_allow_dio = simple_strtoul(buff, NULL, 10) ? 1 : 0;
2824         return count;
2825 }
2826
2827 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2828 {
2829         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2830 }
2831
2832 static ssize_t
2833 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2834                      size_t count, loff_t *off)
2835 {
2836         int num;
2837         unsigned long k = ULONG_MAX;
2838         char buff[11];
2839
2840         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2841                 return -EACCES;
2842         num = (count < 10) ? count : 10;
2843         if (copy_from_user(buff, buffer, num))
2844                 return -EFAULT;
2845         buff[num] = '\0';
2846         k = simple_strtoul(buff, NULL, 10);
2847         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2848                 sg_big_buff = k;
2849                 return count;
2850         }
2851         return -ERANGE;
2852 }
2853
2854 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2855 {
2856         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2857                    sg_version_date);
2858         return 0;
2859 }
2860
2861 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2862 {
2863         return single_open(file, sg_proc_seq_show_version, NULL);
2864 }
2865
2866 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2867 {
2868         seq_printf(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\t"
2869                    "online\n");
2870         return 0;
2871 }
2872
2873 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2874 {
2875         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2876 }
2877
2878 struct sg_proc_deviter {
2879         loff_t  index;
2880         size_t  max;
2881 };
2882
2883 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2884 {
2885         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2886
2887         if (! it)
2888                 return NULL;
2889         if (NULL == sg_dev_arr)
2890                 goto err1;
2891         it->index = *pos;
2892         it->max = sg_last_dev();
2893         if (it->index >= it->max)
2894                 goto err1;
2895         return it;
2896 err1:
2897         kfree(it);
2898         return NULL;
2899 }
2900
2901 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2902 {
2903         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2904
2905         *pos = ++it->index;
2906         return (it->index < it->max) ? it : NULL;
2907 }
2908
2909 static void dev_seq_stop(struct seq_file *s, void *v)
2910 {
2911         kfree (v);
2912 }
2913
2914 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2915 {
2916         return seq_open(file, &dev_seq_ops);
2917 }
2918
2919 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2920 {
2921         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2922         Sg_device *sdp;
2923         struct scsi_device *scsidp;
2924
2925         sdp = it ? sg_get_dev(it->index) : NULL;
2926         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2927                 seq_printf(s, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
2928                               scsidp->host->host_no, scsidp->channel,
2929                               scsidp->id, scsidp->lun, (int) scsidp->type,
2930                               1,
2931                               (int) scsidp->queue_depth,
2932                               (int) scsidp->device_busy,
2933                               (int) scsi_device_online(scsidp));
2934         else
2935                 seq_printf(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2936         return 0;
2937 }
2938
2939 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2940 {
2941         return seq_open(file, &devstrs_seq_ops);
2942 }
2943
2944 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2945 {
2946         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2947         Sg_device *sdp;
2948         struct scsi_device *scsidp;
2949
2950         sdp = it ? sg_get_dev(it->index) : NULL;
2951         if (sdp && (scsidp = sdp->device) && (!sdp->detached))
2952                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2953                            scsidp->vendor, scsidp->model, scsidp->rev);
2954         else
2955                 seq_printf(s, "<no active device>\n");
2956         return 0;
2957 }
2958
2959 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2960 {
2961         int k, m, new_interface, blen, usg;
2962         Sg_request *srp;
2963         Sg_fd *fp;
2964         const sg_io_hdr_t *hp;
2965         const char * cp;
2966
2967         for (k = 0; (fp = sg_get_nth_sfp(sdp, k)); ++k) {
2968                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2969                            "(res)sgat=%d low_dma=%d\n", k + 1,
2970                            sg_jif_to_ms(fp->timeout),
2971                            fp->reserve.bufflen,
2972                            (int) fp->reserve.k_use_sg,
2973                            (int) fp->low_dma);
2974                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=%d\n",
2975                            (int) fp->cmd_q, (int) fp->force_packid,
2976                            (int) fp->keep_orphan, (int) fp->closed);
2977                 for (m = 0; (srp = sg_get_nth_request(fp, m)); ++m) {
2978                         hp = &srp->header;
2979                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2980                         if (srp->res_used) {
2981                                 if (new_interface &&
2982                                     (SG_FLAG_MMAP_IO & hp->flags))
2983                                         cp = "     mmap>> ";
2984                                 else
2985                                         cp = "     rb>> ";
2986                         } else {
2987                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2988                                         cp = "     dio>> ";
2989                                 else
2990                                         cp = "     ";
2991                         }
2992                         seq_printf(s, cp);
2993                         blen = srp->my_cmdp ?
2994                                 srp->my_cmdp->sr_bufflen : srp->data.bufflen;
2995                         usg = srp->my_cmdp ?
2996                                 srp->my_cmdp->sr_use_sg : srp->data.k_use_sg;
2997                         seq_printf(s, srp->done ?
2998                                    ((1 == srp->done) ?  "rcv:" : "fin:")
2999                                    : (srp->my_cmdp ? "act:" : "prior:"));
3000                         seq_printf(s, " id=%d blen=%d",
3001                                    srp->header.pack_id, blen);
3002                         if (srp->done)
3003                                 seq_printf(s, " dur=%d", hp->duration);
3004                         else
3005                                 seq_printf(s, " t_o/elap=%d/%d",
3006                                   new_interface ? hp->timeout : sg_jif_to_ms(fp->timeout),
3007                                   sg_jif_to_ms(hp->duration ? (jiffies - hp->duration) : 0));
3008                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
3009                                    (int) srp->data.cmd_opcode);
3010                 }
3011                 if (0 == m)
3012                         seq_printf(s, "     No requests active\n");
3013         }
3014 }
3015
3016 static int sg_proc_open_debug(struct inode *inode, struct file *file)
3017 {
3018         return seq_open(file, &debug_seq_ops);
3019 }
3020
3021 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
3022 {
3023         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
3024         Sg_device *sdp;
3025
3026         if (it && (0 == it->index)) {
3027                 seq_printf(s, "dev_max(currently)=%d max_active_device=%d "
3028                            "(origin 1)\n", sg_dev_max, (int)it->max);
3029                 seq_printf(s, " def_reserved_size=%d\n", sg_big_buff);
3030         }
3031         sdp = it ? sg_get_dev(it->index) : NULL;
3032         if (sdp) {
3033                 struct scsi_device *scsidp = sdp->device;
3034
3035                 if (NULL == scsidp) {
3036                         seq_printf(s, "device %d detached ??\n",
3037                                    (int)it->index);
3038                         return 0;
3039                 }
3040
3041                 if (sg_get_nth_sfp(sdp, 0)) {
3042                         seq_printf(s, " >>> device=%s ",
3043                                 sdp->disk->disk_name);
3044                         if (sdp->detached)
3045                                 seq_printf(s, "detached pending close ");
3046                         else
3047                                 seq_printf
3048                                     (s, "scsi%d chan=%d id=%d lun=%d   em=%d",
3049                                      scsidp->host->host_no,
3050                                      scsidp->channel, scsidp->id,
3051                                      scsidp->lun,
3052                                      scsidp->host->hostt->emulated);
3053                         seq_printf(s, " sg_tablesize=%d excl=%d\n",
3054                                    sdp->sg_tablesize, sdp->exclude);
3055                 }
3056                 sg_proc_debug_helper(s, sdp);
3057         }
3058         return 0;
3059 }
3060
3061 #endif                          /* CONFIG_SCSI_PROC_FS */
3062
3063 module_init(init_sg);
3064 module_exit(exit_sg);
3065 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);