drivers/staging/keucr/scsiglue.c

   1 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   2
   3 #include <linux/slab.h>
   4 #include <linux/module.h>
   5 #include <linux/mutex.h>
   6
   7 #include <scsi/scsi.h>
   8 #include <scsi/scsi_cmnd.h>
   9 #include <scsi/scsi_devinfo.h>
  10 #include <scsi/scsi_device.h>
  11 #include <scsi/scsi_eh.h>
  12
  13 #include "usb.h"
  14 #include "scsiglue.h"
  15 #include "transport.h"
  16
  17 /* Host functions */
  18 //----- host_info() ---------------------
  19 static const char* host_info(struct Scsi_Host *host)
  20 {
  21         /* pr_info("scsiglue --- host_info\n"); */
  22         return "SCSI emulation for USB Mass Storage devices";
  23 }
  24
  25 //----- slave_alloc() ---------------------
  26 static int slave_alloc(struct scsi_device *sdev)
  27 {
  28         struct us_data *us = host_to_us(sdev->host);
  29
  30         /* pr_info("scsiglue --- slave_alloc\n"); */
  31         sdev->inquiry_len = 36;
  32
  33         blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
  34
  35         if (us->subclass == USB_SC_UFI)
  36                 sdev->sdev_target->pdt_1f_for_no_lun = 1;
  37
  38         return 0;
  39 }
  40
  41 //----- slave_configure() ---------------------
  42 static int slave_configure(struct scsi_device *sdev)
  43 {
  44         struct us_data *us = host_to_us(sdev->host);
  45
  46         /* pr_info("scsiglue --- slave_configure\n"); */
  47         if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN))
  48         {
  49                 unsigned int max_sectors = 64;
  50
  51                 if (us->fflags & US_FL_MAX_SECTORS_MIN)
  52                         max_sectors = PAGE_CACHE_SIZE >> 9;
  53                 if (queue_max_sectors(sdev->request_queue) > max_sectors)
  54                         blk_queue_max_hw_sectors(sdev->request_queue,
  55                                               max_sectors);
  56         }
  57
  58         if (sdev->type == TYPE_DISK)
  59         {
  60                 if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB)
  61                         sdev->use_10_for_ms = 1;
  62                 sdev->use_192_bytes_for_3f = 1;
  63                 if (us->fflags & US_FL_NO_WP_DETECT)
  64                         sdev->skip_ms_page_3f = 1;
  65                 sdev->skip_ms_page_8 = 1;
  66                 if (us->fflags & US_FL_FIX_CAPACITY)
  67                         sdev->fix_capacity = 1;
  68                 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
  69                         sdev->guess_capacity = 1;
  70                 if (sdev->scsi_level > SCSI_2)
  71                         sdev->sdev_target->scsi_level = sdev->scsi_level = SCSI_2;
  72                 sdev->retry_hwerror = 1;
  73                 sdev->allow_restart = 1;
  74                 sdev->last_sector_bug = 1;
  75         }
  76         else
  77         {
  78                 sdev->use_10_for_ms = 1;
  79         }
  80
  81         if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) && sdev->scsi_level == SCSI_UNKNOWN)
  82                 us->max_lun = 0;
  83
  84         if (us->fflags & US_FL_NOT_LOCKABLE)
  85                 sdev->lockable = 0;
  86
  87         return 0;
  88 }
  89
  90 /* This is always called with scsi_lock(host) held */
  91 //----- queuecommand() ---------------------
  92 static int queuecommand_lck(struct scsi_cmnd *srb, void (*done)(struct scsi_cmnd *))
  93 {
  94         struct us_data *us = host_to_us(srb->device->host);
  95
  96         /* pr_info("scsiglue --- queuecommand\n"); */
  97
  98         /* check for state-transition errors */
  99         if (us->srb != NULL)
 100         {
 101                 /* pr_info("Error in %s: us->srb = %p\n"
 102                                  __FUNCTION__, us->srb); */
 103                 return SCSI_MLQUEUE_HOST_BUSY;
 104         }
 105
 106         /* fail the command if we are disconnecting */
 107         if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags))
 108         {
 109                 pr_info("Fail command during disconnect\n");
 110                 srb->result = DID_NO_CONNECT << 16;
 111                 done(srb);
 112                 return 0;
 113         }
 114
 115         /* enqueue the command and wake up the control thread */
 116         srb->scsi_done = done;
 117         us->srb = srb;
 118         complete(&us->cmnd_ready);
 119
 120         return 0;
 121 }
 122
 123 static DEF_SCSI_QCMD(queuecommand)
 124
 125 /***********************************************************************
 126  * Error handling functions
 127  ***********************************************************************/
 128
 129 /* Command timeout and abort */
 130 //----- command_abort() ---------------------
 131 static int command_abort(struct scsi_cmnd *srb)
 132 {
 133         struct us_data *us = host_to_us(srb->device->host);
 134
 135         /* pr_info("scsiglue --- command_abort\n"); */
 136
 137         scsi_lock(us_to_host(us));
 138         if (us->srb != srb)
 139         {
 140                 scsi_unlock(us_to_host(us));
 141                 printk ("-- nothing to abort\n");
 142                 return FAILED;
 143         }
 144
 145         set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
 146         if (!test_bit(US_FLIDX_RESETTING, &us->dflags))
 147         {
 148                 set_bit(US_FLIDX_ABORTING, &us->dflags);
 149                 usb_stor_stop_transport(us);
 150         }
 151         scsi_unlock(us_to_host(us));
 152
 153         /* Wait for the aborted command to finish */
 154         wait_for_completion(&us->notify);
 155         return SUCCESS;
 156 }
 157
 158 /* This invokes the transport reset mechanism to reset the state of the device */
 159 //----- device_reset() ---------------------
 160 static int device_reset(struct scsi_cmnd *srb)
 161 {
 162         struct us_data *us = host_to_us(srb->device->host);
 163         int result;
 164
 165         /* pr_info("scsiglue --- device_reset\n"); */
 166
 167         /* lock the device pointers and do the reset */
 168         mutex_lock(&(us->dev_mutex));
 169         result = us->transport_reset(us);
 170         mutex_unlock(&us->dev_mutex);
 171
 172         return result < 0 ? FAILED : SUCCESS;
 173 }
 174
 175 //----- bus_reset() ---------------------
 176 static int bus_reset(struct scsi_cmnd *srb)
 177 {
 178         struct us_data *us = host_to_us(srb->device->host);
 179         int result;
 180
 181         /* pr_info("scsiglue --- bus_reset\n"); */
 182         result = usb_stor_port_reset(us);
 183         return result < 0 ? FAILED : SUCCESS;
 184 }
 185
 186 //----- usb_stor_report_device_reset() ---------------------
 187 void usb_stor_report_device_reset(struct us_data *us)
 188 {
 189         int i;
 190         struct Scsi_Host *host = us_to_host(us);
 191
 192         /* pr_info("scsiglue --- usb_stor_report_device_reset\n"); */
 193         scsi_report_device_reset(host, 0, 0);
 194         if (us->fflags & US_FL_SCM_MULT_TARG)
 195         {
 196                 for (i = 1; i < host->max_id; ++i)
 197                         scsi_report_device_reset(host, 0, i);
 198         }
 199 }
 200
 201 //----- usb_stor_report_bus_reset() ---------------------
 202 void usb_stor_report_bus_reset(struct us_data *us)
 203 {
 204         struct Scsi_Host *host = us_to_host(us);
 205
 206         /* pr_info("scsiglue --- usb_stor_report_bus_reset\n"); */
 207         scsi_lock(host);
 208         scsi_report_bus_reset(host, 0);
 209         scsi_unlock(host);
 210 }
 211
 212 /***********************************************************************
 213  * /proc/scsi/ functions
 214  ***********************************************************************/
 215
 216 /* we use this macro to help us write into the buffer */
 217 #undef SPRINTF
 218 #define SPRINTF(args...) \
 219         do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
 220
 221 //----- proc_info() ---------------------
 222 static int proc_info (struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
 223 {
 224         struct us_data *us = host_to_us(host);
 225         char *pos = buffer;
 226         const char *string;
 227
 228         /* pr_info("scsiglue --- proc_info\n"); */
 229         if (inout)
 230                 return length;
 231
 232         /* print the controller name */
 233         SPRINTF("   Host scsi%d: usb-storage\n", host->host_no);
 234
 235         /* print product, vendor, and serial number strings */
 236         if (us->pusb_dev->manufacturer)
 237                 string = us->pusb_dev->manufacturer;
 238         else if (us->unusual_dev->vendorName)
 239                 string = us->unusual_dev->vendorName;
 240         else
 241                 string = "Unknown";
 242         SPRINTF("       Vendor: %s\n", string);
 243         if (us->pusb_dev->product)
 244                 string = us->pusb_dev->product;
 245         else if (us->unusual_dev->productName)
 246                 string = us->unusual_dev->productName;
 247         else
 248                 string = "Unknown";
 249         SPRINTF("      Product: %s\n", string);
 250         if (us->pusb_dev->serial)
 251                 string = us->pusb_dev->serial;
 252         else
 253                 string = "None";
 254         SPRINTF("Serial Number: %s\n", string);
 255
 256         /* show the protocol and transport */
 257         SPRINTF("     Protocol: %s\n", us->protocol_name);
 258         SPRINTF("    Transport: %s\n", us->transport_name);
 259
 260         /* show the device flags */
 261         if (pos < buffer + length)
 262         {
 263                 pos += sprintf(pos, "       Quirks:");
 264
 265 #define US_FLAG(name, value) \
 266         if (us->fflags & value) pos += sprintf(pos, " " #name);
 267 US_DO_ALL_FLAGS
 268 #undef US_FLAG
 269
 270                 *(pos++) = '\n';
 271         }
 272
 273         /* Calculate start of next buffer, and return value. */
 274         *start = buffer + offset;
 275
 276         if ((pos - buffer) < offset)
 277                 return (0);
 278         else if ((pos - buffer - offset) < length)
 279                 return (pos - buffer - offset);
 280         else
 281                 return (length);
 282 }
 283
 284 /***********************************************************************
 285  * Sysfs interface
 286  ***********************************************************************/
 287
 288 /* Output routine for the sysfs max_sectors file */
 289 //----- show_max_sectors() ---------------------
 290 static ssize_t show_max_sectors(struct device *dev, struct device_attribute *attr, char *buf)
 291 {
 292         struct scsi_device *sdev = to_scsi_device(dev);
 293
 294         /* pr_info("scsiglue --- ssize_t show_max_sectors\n"); */
 295         return sprintf(buf, "%u\n", queue_max_sectors(sdev->request_queue));
 296 }
 297
 298 /* Input routine for the sysfs max_sectors file */
 299 //----- store_max_sectors() ---------------------
 300 static ssize_t store_max_sectors(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 301 {
 302         struct scsi_device *sdev = to_scsi_device(dev);
 303         unsigned short ms;
 304
 305         /* pr_info("scsiglue --- ssize_t store_max_sectors\n"); */
 306         if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS)
 307         {
 308                 blk_queue_max_hw_sectors(sdev->request_queue, ms);
 309                 return strlen(buf);
 310         }
 311         return -EINVAL;
 312 }
 313
 314 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors, store_max_sectors);
 315 static struct device_attribute *sysfs_device_attr_list[] = {&dev_attr_max_sectors, NULL, };
 316
 317 /* this defines our host template, with which we'll allocate hosts */
 318
 319 //----- usb_stor_host_template() ---------------------
 320 struct scsi_host_template usb_stor_host_template = {
 321         /* basic userland interface stuff */
 322         .name =                         "eucr-storage",
 323         .proc_name =                    "eucr-storage",
 324         .proc_info =                    proc_info,
 325         .info =                         host_info,
 326
 327         /* command interface -- queued only */
 328         .queuecommand =                 queuecommand,
 329
 330         /* error and abort handlers */
 331         .eh_abort_handler =             command_abort,
 332         .eh_device_reset_handler =      device_reset,
 333         .eh_bus_reset_handler =         bus_reset,
 334
 335         /* queue commands only, only one command per LUN */
 336         .can_queue =                    1,
 337         .cmd_per_lun =                  1,
 338
 339         /* unknown initiator id */
 340         .this_id =                      -1,
 341
 342         .slave_alloc =                  slave_alloc,
 343         .slave_configure =              slave_configure,
 344
 345         /* lots of sg segments can be handled */
 346         .sg_tablesize =                 SG_ALL,
 347
 348         /* limit the total size of a transfer to 120 KB */
 349         .max_sectors =                  240,
 350
 351         /* merge commands... this seems to help performance, but
 352          * periodically someone should test to see which setting is more
 353          * optimal.
 354          */
 355         .use_clustering =               1,
 356
 357         /* emulated HBA */
 358         .emulated =                     1,
 359
 360         /* we do our own delay after a device or bus reset */
 361         .skip_settle_delay =            1,
 362
 363         /* sysfs device attributes */
 364         .sdev_attrs =                   sysfs_device_attr_list,
 365
 366         /* module management */
 367         .module =                       THIS_MODULE
 368 };
 369
 370 /* To Report "Illegal Request: Invalid Field in CDB */
 371 unsigned char usb_stor_sense_invalidCDB[18] = {
 372         [0]     = 0x70,                     /* current error */
 373         [2]     = ILLEGAL_REQUEST,          /* Illegal Request = 0x05 */
 374         [7]     = 0x0a,                     /* additional length */
 375         [12]    = 0x24                      /* Invalid Field in CDB */
 376 };
 377
 378 /***********************************************************************
 379  * Scatter-gather transfer buffer access routines
 380  ***********************************************************************/
 381
 382 //----- usb_stor_access_xfer_buf() ---------------------
 383 unsigned int usb_stor_access_xfer_buf(struct us_data *us, unsigned char *buffer,
 384         unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **sgptr,
 385         unsigned int *offset, enum xfer_buf_dir dir)
 386 {
 387         unsigned int cnt;
 388
 389         /* pr_info("transport --- usb_stor_access_xfer_buf\n"); */
 390         struct scatterlist *sg = *sgptr;
 391
 392         if (!sg)
 393                 sg = scsi_sglist(srb);
 394
 395         cnt = 0;
 396         while (cnt < buflen && sg)
 397         {
 398                 struct page *page = sg_page(sg) + ((sg->offset + *offset) >> PAGE_SHIFT);
 399                 unsigned int poff = (sg->offset + *offset) & (PAGE_SIZE-1);
 400                 unsigned int sglen = sg->length - *offset;
 401
 402                 if (sglen > buflen - cnt)
 403                 {
 404                         /* Transfer ends within this s-g entry */
 405                         sglen = buflen - cnt;
 406                         *offset += sglen;
 407                 }
 408                 else
 409                 {
 410                         /* Transfer continues to next s-g entry */
 411                         *offset = 0;
 412                         sg = sg_next(sg);
 413                 }
 414
 415                 while (sglen > 0)
 416                 {
 417                         unsigned int plen = min(sglen, (unsigned int)PAGE_SIZE - poff);
 418                         unsigned char *ptr = kmap(page);
 419
 420                         if (dir == TO_XFER_BUF)
 421                                 memcpy(ptr + poff, buffer + cnt, plen);
 422                         else
 423                                 memcpy(buffer + cnt, ptr + poff, plen);
 424                         kunmap(page);
 425
 426                         /* Start at the beginning of the next page */
 427                         poff = 0;
 428                         ++page;
 429                         cnt += plen;
 430                         sglen -= plen;
 431                 }
 432         }
 433         *sgptr = sg;
 434
 435         /* Return the amount actually transferred */
 436         return cnt;
 437 }
 438
 439 /* Store the contents of buffer into srb's transfer buffer and set the SCSI residue. */
 440 //----- usb_stor_set_xfer_buf() ---------------------
 441 void usb_stor_set_xfer_buf(struct us_data *us, unsigned char *buffer, unsigned int buflen, struct scsi_cmnd *srb,
 442         unsigned int dir)
 443 {
 444         unsigned int offset = 0;
 445         struct scatterlist *sg = NULL;
 446
 447         /* pr_info("transport --- usb_stor_set_xfer_buf\n"); */
 448         // TO_XFER_BUF = 0, FROM_XFER_BUF = 1
 449         buflen = min(buflen, scsi_bufflen(srb));
 450         buflen = usb_stor_access_xfer_buf(us, buffer, buflen, srb, &sg, &offset, dir);
 451         if (buflen < scsi_bufflen(srb))
 452                 scsi_set_resid(srb, scsi_bufflen(srb) - buflen);
 453 }