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 /*
  19  * host_info()
  20  */
  21 static const char *host_info(struct Scsi_Host *host)
  22 {
  23         /* pr_info("scsiglue --- host_info\n"); */
  24         return "SCSI emulation for USB Mass Storage devices";
  25 }
  26
  27 /*
  28  * slave_alloc()
  29  */
  30 static int slave_alloc(struct scsi_device *sdev)
  31 {
  32         struct us_data *us = host_to_us(sdev->host);
  33
  34         /* pr_info("scsiglue --- slave_alloc\n"); */
  35         sdev->inquiry_len = 36;
  36
  37         blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
  38
  39         if (us->subclass == USB_SC_UFI)
  40                 sdev->sdev_target->pdt_1f_for_no_lun = 1;
  41
  42         return 0;
  43 }
  44
  45 /*
  46  * slave_configure()
  47  */
  48 static int slave_configure(struct scsi_device *sdev)
  49 {
  50         struct us_data *us = host_to_us(sdev->host);
  51
  52         /* pr_info("scsiglue --- slave_configure\n"); */
  53         if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
  54                 unsigned int max_sectors = 64;
  55
  56                 if (us->fflags & US_FL_MAX_SECTORS_MIN)
  57                         max_sectors = PAGE_CACHE_SIZE >> 9;
  58                 if (queue_max_sectors(sdev->request_queue) > max_sectors)
  59                         blk_queue_max_hw_sectors(sdev->request_queue,
  60                                               max_sectors);
  61         }
  62
  63         if (sdev->type == TYPE_DISK) {
  64                 if (us->subclass != USB_SC_SCSI &&
  65                         us->subclass != USB_SC_CYP_ATACB)
  66                         sdev->use_10_for_ms = 1;
  67                 sdev->use_192_bytes_for_3f = 1;
  68                 if (us->fflags & US_FL_NO_WP_DETECT)
  69                         sdev->skip_ms_page_3f = 1;
  70                 sdev->skip_ms_page_8 = 1;
  71                 if (us->fflags & US_FL_FIX_CAPACITY)
  72                         sdev->fix_capacity = 1;
  73                 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
  74                         sdev->guess_capacity = 1;
  75                 if (sdev->scsi_level > SCSI_2)
  76                         sdev->sdev_target->scsi_level = sdev->scsi_level
  77                                                                 = SCSI_2;
  78                 sdev->retry_hwerror = 1;
  79                 sdev->allow_restart = 1;
  80                 sdev->last_sector_bug = 1;
  81         } else {
  82                 sdev->use_10_for_ms = 1;
  83         }
  84
  85         if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
  86                                         sdev->scsi_level == SCSI_UNKNOWN)
  87                 us->max_lun = 0;
  88
  89         if (us->fflags & US_FL_NOT_LOCKABLE)
  90                 sdev->lockable = 0;
  91
  92         return 0;
  93 }
  94
  95 /* This is always called with scsi_lock(host) held */
  96 /*
  97  * queuecommand()
  98  */
  99 static int queuecommand_lck(struct scsi_cmnd *srb,
 100                                 void (*done)(struct scsi_cmnd *))
 101 {
 102         struct us_data *us = host_to_us(srb->device->host);
 103
 104         /* pr_info("scsiglue --- queuecommand\n"); */
 105
 106         /* check for state-transition errors */
 107         if (us->srb != NULL) {
 108                 /* pr_info("Error in %s: us->srb = %p\n"
 109                                  __FUNCTION__, us->srb); */
 110                 return SCSI_MLQUEUE_HOST_BUSY;
 111         }
 112
 113         /* fail the command if we are disconnecting */
 114         if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
 115                 pr_info("Fail command during disconnect\n");
 116                 srb->result = DID_NO_CONNECT << 16;
 117                 done(srb);
 118                 return 0;
 119         }
 120
 121         /* enqueue the command and wake up the control thread */
 122         srb->scsi_done = done;
 123         us->srb = srb;
 124         complete(&us->cmnd_ready);
 125
 126         return 0;
 127 }
 128
 129 static DEF_SCSI_QCMD(queuecommand)
 130
 131 /***********************************************************************
 132  * Error handling functions
 133  ***********************************************************************/
 134
 135 /* Command timeout and abort */
 136 /*
 137  * command_abort()
 138  */
 139 static int command_abort(struct scsi_cmnd *srb)
 140 {
 141         struct us_data *us = host_to_us(srb->device->host);
 142
 143         /* pr_info("scsiglue --- command_abort\n"); */
 144
 145         scsi_lock(us_to_host(us));
 146         if (us->srb != srb) {
 147                 scsi_unlock(us_to_host(us));
 148                 dev_info(&us->pusb_dev->dev, "-- nothing to abort\n");
 149                 return FAILED;
 150         }
 151
 152         set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
 153         if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
 154                 set_bit(US_FLIDX_ABORTING, &us->dflags);
 155                 usb_stor_stop_transport(us);
 156         }
 157         scsi_unlock(us_to_host(us));
 158
 159         /* Wait for the aborted command to finish */
 160         wait_for_completion(&us->notify);
 161         return SUCCESS;
 162 }
 163
 164 /* This invokes the transport reset mechanism to reset the state of the
 165  * device.
 166  */
 167 /*
 168  * device_reset()
 169  */
 170 static int device_reset(struct scsi_cmnd *srb)
 171 {
 172         struct us_data *us = host_to_us(srb->device->host);
 173         int result;
 174
 175         /* pr_info("scsiglue --- device_reset\n"); */
 176
 177         /* lock the device pointers and do the reset */
 178         mutex_lock(&(us->dev_mutex));
 179         result = us->transport_reset(us);
 180         mutex_unlock(&us->dev_mutex);
 181
 182         return result < 0 ? FAILED : SUCCESS;
 183 }
 184
 185 /*
 186  * bus_reset()
 187  */
 188 static int bus_reset(struct scsi_cmnd *srb)
 189 {
 190         struct us_data *us = host_to_us(srb->device->host);
 191         int result;
 192
 193         /* pr_info("scsiglue --- bus_reset\n"); */
 194         result = usb_stor_port_reset(us);
 195         return result < 0 ? FAILED : SUCCESS;
 196 }
 197
 198 /*
 199  * usb_stor_report_device_reset()
 200  */
 201 void usb_stor_report_device_reset(struct us_data *us)
 202 {
 203         int i;
 204         struct Scsi_Host *host = us_to_host(us);
 205
 206         /* pr_info("scsiglue --- usb_stor_report_device_reset\n"); */
 207         scsi_report_device_reset(host, 0, 0);
 208         if (us->fflags & US_FL_SCM_MULT_TARG) {
 209                 for (i = 1; i < host->max_id; ++i)
 210                         scsi_report_device_reset(host, 0, i);
 211         }
 212 }
 213
 214 /*
 215  * usb_stor_report_bus_reset()
 216  */
 217 void usb_stor_report_bus_reset(struct us_data *us)
 218 {
 219         struct Scsi_Host *host = us_to_host(us);
 220
 221         /* pr_info("scsiglue --- usb_stor_report_bus_reset\n"); */
 222         scsi_lock(host);
 223         scsi_report_bus_reset(host, 0);
 224         scsi_unlock(host);
 225 }
 226
 227 /***********************************************************************
 228  * /proc/scsi/ functions
 229  ***********************************************************************/
 230
 231 /* we use this macro to help us write into the buffer */
 232 #undef SPRINTF
 233 #define SPRINTF(args...) seq_printf(m, ##args)
 234
 235 static int write_info(struct Scsi_Host *host, char *buffer, int length)
 236 {
 237         return length;
 238 }
 239
 240 static int show_info(struct seq_file *m, struct Scsi_Host *host)
 241 {
 242         struct us_data *us = host_to_us(host);
 243         const char *string;
 244
 245         /* print the controller name */
 246         SPRINTF("   Host scsi%d: usb-storage\n", host->host_no);
 247
 248         /* print product, vendor, and serial number strings */
 249         if (us->pusb_dev->manufacturer)
 250                 string = us->pusb_dev->manufacturer;
 251         else if (us->unusual_dev->vendorName)
 252                 string = us->unusual_dev->vendorName;
 253         else
 254                 string = "Unknown";
 255         SPRINTF("       Vendor: %s\n", string);
 256         if (us->pusb_dev->product)
 257                 string = us->pusb_dev->product;
 258         else if (us->unusual_dev->productName)
 259                 string = us->unusual_dev->productName;
 260         else
 261                 string = "Unknown";
 262         SPRINTF("      Product: %s\n", string);
 263         if (us->pusb_dev->serial)
 264                 string = us->pusb_dev->serial;
 265         else
 266                 string = "None";
 267         SPRINTF("Serial Number: %s\n", string);
 268
 269         /* show the protocol and transport */
 270         SPRINTF("     Protocol: %s\n", us->protocol_name);
 271         SPRINTF("    Transport: %s\n", us->transport_name);
 272
 273         /* show the device flags */
 274         SPRINTF("       Quirks:");
 275
 276 #define US_FLAG(name, value) \
 277         do { \
 278                 if (us->fflags & value) \
 279                         SPRINTF(" " #name); \
 280         } while (0);
 281 US_DO_ALL_FLAGS
 282 #undef US_FLAG
 283         seq_putc(m, '\n');
 284         return 0;
 285 }
 286
 287 /***********************************************************************
 288  * Sysfs interface
 289  ***********************************************************************/
 290
 291 /* Output routine for the sysfs max_sectors file */
 292 static ssize_t max_sectors_show(struct device *dev,
 293                                 struct device_attribute *attr, char *buf)
 294 {
 295         struct scsi_device *sdev = to_scsi_device(dev);
 296
 297         /* pr_info("scsiglue --- ssize_t show_max_sectors\n"); */
 298         return sprintf(buf, "%u\n", queue_max_sectors(sdev->request_queue));
 299 }
 300
 301 /* Input routine for the sysfs max_sectors file */
 302 static ssize_t max_sectors_store(struct device *dev,
 303                                 struct device_attribute *attr,
 304                                 const char *buf, size_t count)
 305 {
 306         struct scsi_device *sdev = to_scsi_device(dev);
 307         unsigned short ms;
 308
 309         /* pr_info("scsiglue --- ssize_t store_max_sectors\n"); */
 310         if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
 311                 blk_queue_max_hw_sectors(sdev->request_queue, ms);
 312                 return strlen(buf);
 313         }
 314         return -EINVAL;
 315 }
 316 static DEVICE_ATTR_RW(max_sectors);
 317
 318 static struct device_attribute *sysfs_device_attr_list[] = {
 319         &dev_attr_max_sectors, NULL,
 320 };
 321
 322 /* this defines our host template, with which we'll allocate hosts */
 323
 324 /*
 325  * usb_stor_host_template()
 326  */
 327 struct scsi_host_template usb_stor_host_template = {
 328         /* basic userland interface stuff */
 329         .name =                         "eucr-storage",
 330         .proc_name =                    "eucr-storage",
 331         .write_info =                   write_info,
 332         .show_info =                    show_info,
 333         .info =                         host_info,
 334
 335         /* command interface -- queued only */
 336         .queuecommand =                 queuecommand,
 337
 338         /* error and abort handlers */
 339         .eh_abort_handler =             command_abort,
 340         .eh_device_reset_handler =      device_reset,
 341         .eh_bus_reset_handler =         bus_reset,
 342
 343         /* queue commands only, only one command per LUN */
 344         .can_queue =                    1,
 345         .cmd_per_lun =                  1,
 346
 347         /* unknown initiator id */
 348         .this_id =                      -1,
 349
 350         .slave_alloc =                  slave_alloc,
 351         .slave_configure =              slave_configure,
 352
 353         /* lots of sg segments can be handled */
 354         .sg_tablesize =                 SG_ALL,
 355
 356         /* limit the total size of a transfer to 120 KB */
 357         .max_sectors =                  240,
 358
 359         /* merge commands... this seems to help performance, but
 360          * periodically someone should test to see which setting is more
 361          * optimal.
 362          */
 363         .use_clustering =               1,
 364
 365         /* emulated HBA */
 366         .emulated =                     1,
 367
 368         /* we do our own delay after a device or bus reset */
 369         .skip_settle_delay =            1,
 370
 371         /* sysfs device attributes */
 372         .sdev_attrs =                   sysfs_device_attr_list,
 373
 374         /* module management */
 375         .module =                       THIS_MODULE
 376 };
 377
 378 /* To Report "Illegal Request: Invalid Field in CDB */
 379 unsigned char usb_stor_sense_invalidCDB[18] = {
 380         [0]     = 0x70,                     /* current error */
 381         [2]     = ILLEGAL_REQUEST,          /* Illegal Request = 0x05 */
 382         [7]     = 0x0a,                     /* additional length */
 383         [12]    = 0x24                      /* Invalid Field in CDB */
 384 };
 385
 386 /***********************************************************************
 387  * Scatter-gather transfer buffer access routines
 388  ***********************************************************************/
 389
 390 /*
 391  * usb_stor_access_xfer_buf()
 392  */
 393 unsigned int usb_stor_access_xfer_buf(struct us_data *us,
 394         unsigned char *buffer, unsigned int buflen,
 395         struct scsi_cmnd *srb, struct scatterlist **sgptr,
 396         unsigned int *offset, enum xfer_buf_dir dir)
 397 {
 398         unsigned int cnt;
 399
 400         /* pr_info("transport --- usb_stor_access_xfer_buf\n"); */
 401         struct scatterlist *sg = *sgptr;
 402
 403         if (!sg)
 404                 sg = scsi_sglist(srb);
 405
 406         cnt = 0;
 407         while (cnt < buflen && sg) {
 408                 struct page *page = sg_page(sg) +
 409                                         ((sg->offset + *offset) >> PAGE_SHIFT);
 410                 unsigned int poff = (sg->offset + *offset) & (PAGE_SIZE-1);
 411                 unsigned int sglen = sg->length - *offset;
 412
 413                 if (sglen > buflen - cnt) {
 414                         /* Transfer ends within this s-g entry */
 415                         sglen = buflen - cnt;
 416                         *offset += sglen;
 417                 } else {
 418                         /* Transfer continues to next s-g entry */
 419                         *offset = 0;
 420                         sg = sg_next(sg);
 421                 }
 422
 423                 while (sglen > 0) {
 424                         unsigned int plen = min(sglen,
 425                                         (unsigned int)PAGE_SIZE - poff);
 426                         unsigned char *ptr = kmap(page);
 427
 428                         if (dir == TO_XFER_BUF)
 429                                 memcpy(ptr + poff, buffer + cnt, plen);
 430                         else
 431                                 memcpy(buffer + cnt, ptr + poff, plen);
 432                         kunmap(page);
 433
 434                         /* Start at the beginning of the next page */
 435                         poff = 0;
 436                         ++page;
 437                         cnt += plen;
 438                         sglen -= plen;
 439                 }
 440         }
 441         *sgptr = sg;
 442
 443         /* Return the amount actually transferred */
 444         return cnt;
 445 }
 446
 447 /*
 448  * Store the contents of buffer into srb's transfer
 449  * buffer and set the SCSI residue.
 450  */
 451 /*
 452  * usb_stor_set_xfer_buf()
 453  */
 454 void usb_stor_set_xfer_buf(struct us_data *us, unsigned char *buffer,
 455                 unsigned int buflen, struct scsi_cmnd *srb, unsigned int dir)
 456 {
 457         unsigned int offset = 0;
 458         struct scatterlist *sg = NULL;
 459
 460         /* pr_info("transport --- usb_stor_set_xfer_buf\n"); */
 461         /* TO_XFER_BUF = 0, FROM_XFER_BUF = 1 */
 462         buflen = min(buflen, scsi_bufflen(srb));
 463         buflen = usb_stor_access_xfer_buf(us, buffer, buflen, srb,
 464                                                 &sg, &offset, dir);
 465         if (buflen < scsi_bufflen(srb))
 466                 scsi_set_resid(srb, scsi_bufflen(srb) - buflen);
 467 }