drivers/scsi/libsrp.c

   1 /*
   2  * SCSI RDAM Protocol lib functions
   3  *
   4  * Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19  * 02110-1301 USA
  20  */
  21 #include <linux/err.h>
  22 #include <linux/kfifo.h>
  23 #include <linux/scatterlist.h>
  24 #include <linux/dma-mapping.h>
  25 #include <scsi/scsi.h>
  26 #include <scsi/scsi_cmnd.h>
  27 #include <scsi/scsi_tcq.h>
  28 #include <scsi/scsi_tgt.h>
  29 #include <scsi/srp.h>
  30 #include <scsi/libsrp.h>
  31
  32 enum srp_task_attributes {
  33         SRP_SIMPLE_TASK = 0,
  34         SRP_HEAD_TASK = 1,
  35         SRP_ORDERED_TASK = 2,
  36         SRP_ACA_TASK = 4
  37 };
  38
  39 /* tmp - will replace with SCSI logging stuff */
  40 #define eprintk(fmt, args...)                                   \
  41 do {                                                            \
  42         printk("%s(%d) " fmt, __FUNCTION__, __LINE__, ##args);  \
  43 } while (0)
  44 /* #define dprintk eprintk */
  45 #define dprintk(fmt, args...)
  46
  47 static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
  48                              struct srp_buf **ring)
  49 {
  50         int i;
  51         struct iu_entry *iue;
  52
  53         q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
  54         if (!q->pool)
  55                 return -ENOMEM;
  56         q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
  57         if (!q->items)
  58                 goto free_pool;
  59
  60         spin_lock_init(&q->lock);
  61         q->queue = kfifo_init((void *) q->pool, max * sizeof(void *),
  62                               GFP_KERNEL, &q->lock);
  63         if (IS_ERR(q->queue))
  64                 goto free_item;
  65
  66         for (i = 0, iue = q->items; i < max; i++) {
  67                 __kfifo_put(q->queue, (void *) &iue, sizeof(void *));
  68                 iue->sbuf = ring[i];
  69                 iue++;
  70         }
  71         return 0;
  72
  73 free_item:
  74         kfree(q->items);
  75 free_pool:
  76         kfree(q->pool);
  77         return -ENOMEM;
  78 }
  79
  80 static void srp_iu_pool_free(struct srp_queue *q)
  81 {
  82         kfree(q->items);
  83         kfree(q->pool);
  84 }
  85
  86 static struct srp_buf **srp_ring_alloc(struct device *dev,
  87                                        size_t max, size_t size)
  88 {
  89         int i;
  90         struct srp_buf **ring;
  91
  92         ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
  93         if (!ring)
  94                 return NULL;
  95
  96         for (i = 0; i < max; i++) {
  97                 ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
  98                 if (!ring[i])
  99                         goto out;
 100                 ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
 101                                                   GFP_KERNEL);
 102                 if (!ring[i]->buf)
 103                         goto out;
 104         }
 105         return ring;
 106
 107 out:
 108         for (i = 0; i < max && ring[i]; i++) {
 109                 if (ring[i]->buf)
 110                         dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
 111                 kfree(ring[i]);
 112         }
 113         kfree(ring);
 114
 115         return NULL;
 116 }
 117
 118 static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
 119                           size_t size)
 120 {
 121         int i;
 122
 123         for (i = 0; i < max; i++) {
 124                 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
 125                 kfree(ring[i]);
 126         }
 127 }
 128
 129 int srp_target_alloc(struct srp_target *target, struct device *dev,
 130                      size_t nr, size_t iu_size)
 131 {
 132         int err;
 133
 134         spin_lock_init(&target->lock);
 135         INIT_LIST_HEAD(&target->cmd_queue);
 136
 137         target->dev = dev;
 138         target->dev->driver_data = target;
 139
 140         target->srp_iu_size = iu_size;
 141         target->rx_ring_size = nr;
 142         target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
 143         if (!target->rx_ring)
 144                 return -ENOMEM;
 145         err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
 146         if (err)
 147                 goto free_ring;
 148
 149         return 0;
 150
 151 free_ring:
 152         srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
 153         return -ENOMEM;
 154 }
 155 EXPORT_SYMBOL_GPL(srp_target_alloc);
 156
 157 void srp_target_free(struct srp_target *target)
 158 {
 159         srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
 160                       target->srp_iu_size);
 161         srp_iu_pool_free(&target->iu_queue);
 162 }
 163 EXPORT_SYMBOL_GPL(srp_target_free);
 164
 165 struct iu_entry *srp_iu_get(struct srp_target *target)
 166 {
 167         struct iu_entry *iue = NULL;
 168
 169         kfifo_get(target->iu_queue.queue, (void *) &iue, sizeof(void *));
 170         if (!iue)
 171                 return iue;
 172         iue->target = target;
 173         INIT_LIST_HEAD(&iue->ilist);
 174         iue->flags = 0;
 175         return iue;
 176 }
 177 EXPORT_SYMBOL_GPL(srp_iu_get);
 178
 179 void srp_iu_put(struct iu_entry *iue)
 180 {
 181         kfifo_put(iue->target->iu_queue.queue, (void *) &iue, sizeof(void *));
 182 }
 183 EXPORT_SYMBOL_GPL(srp_iu_put);
 184
 185 static int srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
 186                            enum dma_data_direction dir, srp_rdma_t rdma_io,
 187                            int dma_map, int ext_desc)
 188 {
 189         struct iu_entry *iue = NULL;
 190         struct scatterlist *sg = NULL;
 191         int err, nsg = 0, len;
 192
 193         if (dma_map) {
 194                 iue = (struct iu_entry *) sc->SCp.ptr;
 195                 sg = sc->request_buffer;
 196
 197                 dprintk("%p %u %u %d\n", iue, sc->request_bufflen,
 198                         md->len, sc->use_sg);
 199
 200                 nsg = dma_map_sg(iue->target->dev, sg, sc->use_sg,
 201                                  DMA_BIDIRECTIONAL);
 202                 if (!nsg) {
 203                         printk("fail to map %p %d\n", iue, sc->use_sg);
 204                         return 0;
 205                 }
 206                 len = min(sc->request_bufflen, md->len);
 207         } else
 208                 len = md->len;
 209
 210         err = rdma_io(sc, sg, nsg, md, 1, dir, len);
 211
 212         if (dma_map)
 213                 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
 214
 215         return err;
 216 }
 217
 218 static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
 219                              struct srp_indirect_buf *id,
 220                              enum dma_data_direction dir, srp_rdma_t rdma_io,
 221                              int dma_map, int ext_desc)
 222 {
 223         struct iu_entry *iue = NULL;
 224         struct srp_direct_buf *md = NULL;
 225         struct scatterlist dummy, *sg = NULL;
 226         dma_addr_t token = 0;
 227         int err = 0;
 228         int nmd, nsg = 0, len;
 229
 230         if (dma_map || ext_desc) {
 231                 iue = (struct iu_entry *) sc->SCp.ptr;
 232                 sg = sc->request_buffer;
 233
 234                 dprintk("%p %u %u %d %d\n",
 235                         iue, sc->request_bufflen, id->len,
 236                         cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
 237         }
 238
 239         nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
 240
 241         if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
 242             (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
 243                 md = &id->desc_list[0];
 244                 goto rdma;
 245         }
 246
 247         if (ext_desc && dma_map) {
 248                 md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
 249                                 &token, GFP_KERNEL);
 250                 if (!md) {
 251                         eprintk("Can't get dma memory %u\n", id->table_desc.len);
 252                         return -ENOMEM;
 253                 }
 254
 255                 sg_init_one(&dummy, md, id->table_desc.len);
 256                 sg_dma_address(&dummy) = token;
 257                 sg_dma_len(&dummy) = id->table_desc.len;
 258                 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
 259                               id->table_desc.len);
 260                 if (err) {
 261                         eprintk("Error copying indirect table %d\n", err);
 262                         goto free_mem;
 263                 }
 264         } else {
 265                 eprintk("This command uses external indirect buffer\n");
 266                 return -EINVAL;
 267         }
 268
 269 rdma:
 270         if (dma_map) {
 271                 nsg = dma_map_sg(iue->target->dev, sg, sc->use_sg, DMA_BIDIRECTIONAL);
 272                 if (!nsg) {
 273                         eprintk("fail to map %p %d\n", iue, sc->use_sg);
 274                         err = -EIO;
 275                         goto free_mem;
 276                 }
 277                 len = min(sc->request_bufflen, id->len);
 278         } else
 279                 len = id->len;
 280
 281         err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
 282
 283         if (dma_map)
 284                 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
 285
 286 free_mem:
 287         if (token && dma_map)
 288                 dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
 289
 290         return err;
 291 }
 292
 293 static int data_out_desc_size(struct srp_cmd *cmd)
 294 {
 295         int size = 0;
 296         u8 fmt = cmd->buf_fmt >> 4;
 297
 298         switch (fmt) {
 299         case SRP_NO_DATA_DESC:
 300                 break;
 301         case SRP_DATA_DESC_DIRECT:
 302                 size = sizeof(struct srp_direct_buf);
 303                 break;
 304         case SRP_DATA_DESC_INDIRECT:
 305                 size = sizeof(struct srp_indirect_buf) +
 306                         sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
 307                 break;
 308         default:
 309                 eprintk("client error. Invalid data_out_format %x\n", fmt);
 310                 break;
 311         }
 312         return size;
 313 }
 314
 315 /*
 316  * TODO: this can be called multiple times for a single command if it
 317  * has very long data.
 318  */
 319 int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
 320                       srp_rdma_t rdma_io, int dma_map, int ext_desc)
 321 {
 322         struct srp_direct_buf *md;
 323         struct srp_indirect_buf *id;
 324         enum dma_data_direction dir;
 325         int offset, err = 0;
 326         u8 format;
 327
 328         offset = cmd->add_cdb_len * 4;
 329
 330         dir = srp_cmd_direction(cmd);
 331         if (dir == DMA_FROM_DEVICE)
 332                 offset += data_out_desc_size(cmd);
 333
 334         if (dir == DMA_TO_DEVICE)
 335                 format = cmd->buf_fmt >> 4;
 336         else
 337                 format = cmd->buf_fmt & ((1U << 4) - 1);
 338
 339         switch (format) {
 340         case SRP_NO_DATA_DESC:
 341                 break;
 342         case SRP_DATA_DESC_DIRECT:
 343                 md = (struct srp_direct_buf *)
 344                         (cmd->add_data + offset);
 345                 err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
 346                 break;
 347         case SRP_DATA_DESC_INDIRECT:
 348                 id = (struct srp_indirect_buf *)
 349                         (cmd->add_data + offset);
 350                 err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
 351                                         ext_desc);
 352                 break;
 353         default:
 354                 eprintk("Unknown format %d %x\n", dir, format);
 355                 err = -EINVAL;
 356         }
 357
 358         return err;
 359 }
 360 EXPORT_SYMBOL_GPL(srp_transfer_data);
 361
 362 static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
 363 {
 364         struct srp_direct_buf *md;
 365         struct srp_indirect_buf *id;
 366         int len = 0, offset = cmd->add_cdb_len * 4;
 367         u8 fmt;
 368
 369         if (dir == DMA_TO_DEVICE)
 370                 fmt = cmd->buf_fmt >> 4;
 371         else {
 372                 fmt = cmd->buf_fmt & ((1U << 4) - 1);
 373                 offset += data_out_desc_size(cmd);
 374         }
 375
 376         switch (fmt) {
 377         case SRP_NO_DATA_DESC:
 378                 break;
 379         case SRP_DATA_DESC_DIRECT:
 380                 md = (struct srp_direct_buf *) (cmd->add_data + offset);
 381                 len = md->len;
 382                 break;
 383         case SRP_DATA_DESC_INDIRECT:
 384                 id = (struct srp_indirect_buf *) (cmd->add_data + offset);
 385                 len = id->len;
 386                 break;
 387         default:
 388                 eprintk("invalid data format %x\n", fmt);
 389                 break;
 390         }
 391         return len;
 392 }
 393
 394 int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
 395                   u64 addr)
 396 {
 397         enum dma_data_direction dir;
 398         struct scsi_cmnd *sc;
 399         int tag, len, err;
 400
 401         switch (cmd->task_attr) {
 402         case SRP_SIMPLE_TASK:
 403                 tag = MSG_SIMPLE_TAG;
 404                 break;
 405         case SRP_ORDERED_TASK:
 406                 tag = MSG_ORDERED_TAG;
 407                 break;
 408         case SRP_HEAD_TASK:
 409                 tag = MSG_HEAD_TAG;
 410                 break;
 411         default:
 412                 eprintk("Task attribute %d not supported\n", cmd->task_attr);
 413                 tag = MSG_ORDERED_TAG;
 414         }
 415
 416         dir = srp_cmd_direction(cmd);
 417         len = vscsis_data_length(cmd, dir);
 418
 419         dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
 420                 cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
 421
 422         sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
 423         if (!sc)
 424                 return -ENOMEM;
 425
 426         sc->SCp.ptr = info;
 427         memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
 428         sc->request_bufflen = len;
 429         sc->request_buffer = (void *) (unsigned long) addr;
 430         sc->tag = tag;
 431         err = scsi_tgt_queue_command(sc, (struct scsi_lun *) &cmd->lun, cmd->tag);
 432         if (err)
 433                 scsi_host_put_command(shost, sc);
 434
 435         return err;
 436 }
 437 EXPORT_SYMBOL_GPL(srp_cmd_queue);
 438
 439 MODULE_DESCRIPTION("SCSI RDAM Protocol lib functions");
 440 MODULE_AUTHOR("FUJITA Tomonori");
 441 MODULE_LICENSE("GPL");