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, __func__, __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         kfifo_init(&q->queue, (void *) q->pool, max * sizeof(void *),
  62                               &q->lock);
  63
  64         for (i = 0, iue = q->items; i < max; i++) {
  65                 __kfifo_put(&q->queue, (void *) &iue, sizeof(void *));
  66                 iue->sbuf = ring[i];
  67                 iue++;
  68         }
  69         return 0;
  70
  71         kfree(q->items);
  72 free_pool:
  73         kfree(q->pool);
  74         return -ENOMEM;
  75 }
  76
  77 static void srp_iu_pool_free(struct srp_queue *q)
  78 {
  79         kfree(q->items);
  80         kfree(q->pool);
  81 }
  82
  83 static struct srp_buf **srp_ring_alloc(struct device *dev,
  84                                        size_t max, size_t size)
  85 {
  86         int i;
  87         struct srp_buf **ring;
  88
  89         ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
  90         if (!ring)
  91                 return NULL;
  92
  93         for (i = 0; i < max; i++) {
  94                 ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
  95                 if (!ring[i])
  96                         goto out;
  97                 ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
  98                                                   GFP_KERNEL);
  99                 if (!ring[i]->buf)
 100                         goto out;
 101         }
 102         return ring;
 103
 104 out:
 105         for (i = 0; i < max && ring[i]; i++) {
 106                 if (ring[i]->buf)
 107                         dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
 108                 kfree(ring[i]);
 109         }
 110         kfree(ring);
 111
 112         return NULL;
 113 }
 114
 115 static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
 116                           size_t size)
 117 {
 118         int i;
 119
 120         for (i = 0; i < max; i++) {
 121                 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
 122                 kfree(ring[i]);
 123         }
 124         kfree(ring);
 125 }
 126
 127 int srp_target_alloc(struct srp_target *target, struct device *dev,
 128                      size_t nr, size_t iu_size)
 129 {
 130         int err;
 131
 132         spin_lock_init(&target->lock);
 133         INIT_LIST_HEAD(&target->cmd_queue);
 134
 135         target->dev = dev;
 136         dev_set_drvdata(target->dev, target);
 137
 138         target->srp_iu_size = iu_size;
 139         target->rx_ring_size = nr;
 140         target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
 141         if (!target->rx_ring)
 142                 return -ENOMEM;
 143         err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
 144         if (err)
 145                 goto free_ring;
 146
 147         return 0;
 148
 149 free_ring:
 150         srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
 151         return -ENOMEM;
 152 }
 153 EXPORT_SYMBOL_GPL(srp_target_alloc);
 154
 155 void srp_target_free(struct srp_target *target)
 156 {
 157         srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
 158                       target->srp_iu_size);
 159         srp_iu_pool_free(&target->iu_queue);
 160 }
 161 EXPORT_SYMBOL_GPL(srp_target_free);
 162
 163 struct iu_entry *srp_iu_get(struct srp_target *target)
 164 {
 165         struct iu_entry *iue = NULL;
 166
 167         kfifo_get(&target->iu_queue.queue, (void *) &iue, sizeof(void *));
 168         if (!iue)
 169                 return iue;
 170         iue->target = target;
 171         INIT_LIST_HEAD(&iue->ilist);
 172         iue->flags = 0;
 173         return iue;
 174 }
 175 EXPORT_SYMBOL_GPL(srp_iu_get);
 176
 177 void srp_iu_put(struct iu_entry *iue)
 178 {
 179         kfifo_put(&iue->target->iu_queue.queue, (void *) &iue, sizeof(void *));
 180 }
 181 EXPORT_SYMBOL_GPL(srp_iu_put);
 182
 183 static int srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
 184                            enum dma_data_direction dir, srp_rdma_t rdma_io,
 185                            int dma_map, int ext_desc)
 186 {
 187         struct iu_entry *iue = NULL;
 188         struct scatterlist *sg = NULL;
 189         int err, nsg = 0, len;
 190
 191         if (dma_map) {
 192                 iue = (struct iu_entry *) sc->SCp.ptr;
 193                 sg = scsi_sglist(sc);
 194
 195                 dprintk("%p %u %u %d\n", iue, scsi_bufflen(sc),
 196                         md->len, scsi_sg_count(sc));
 197
 198                 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
 199                                  DMA_BIDIRECTIONAL);
 200                 if (!nsg) {
 201                         printk("fail to map %p %d\n", iue, scsi_sg_count(sc));
 202                         return 0;
 203                 }
 204                 len = min(scsi_bufflen(sc), md->len);
 205         } else
 206                 len = md->len;
 207
 208         err = rdma_io(sc, sg, nsg, md, 1, dir, len);
 209
 210         if (dma_map)
 211                 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
 212
 213         return err;
 214 }
 215
 216 static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
 217                              struct srp_indirect_buf *id,
 218                              enum dma_data_direction dir, srp_rdma_t rdma_io,
 219                              int dma_map, int ext_desc)
 220 {
 221         struct iu_entry *iue = NULL;
 222         struct srp_direct_buf *md = NULL;
 223         struct scatterlist dummy, *sg = NULL;
 224         dma_addr_t token = 0;
 225         int err = 0;
 226         int nmd, nsg = 0, len;
 227
 228         if (dma_map || ext_desc) {
 229                 iue = (struct iu_entry *) sc->SCp.ptr;
 230                 sg = scsi_sglist(sc);
 231
 232                 dprintk("%p %u %u %d %d\n",
 233                         iue, scsi_bufflen(sc), id->len,
 234                         cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
 235         }
 236
 237         nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
 238
 239         if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
 240             (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
 241                 md = &id->desc_list[0];
 242                 goto rdma;
 243         }
 244
 245         if (ext_desc && dma_map) {
 246                 md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
 247                                 &token, GFP_KERNEL);
 248                 if (!md) {
 249                         eprintk("Can't get dma memory %u\n", id->table_desc.len);
 250                         return -ENOMEM;
 251                 }
 252
 253                 sg_init_one(&dummy, md, id->table_desc.len);
 254                 sg_dma_address(&dummy) = token;
 255                 sg_dma_len(&dummy) = id->table_desc.len;
 256                 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
 257                               id->table_desc.len);
 258                 if (err) {
 259                         eprintk("Error copying indirect table %d\n", err);
 260                         goto free_mem;
 261                 }
 262         } else {
 263                 eprintk("This command uses external indirect buffer\n");
 264                 return -EINVAL;
 265         }
 266
 267 rdma:
 268         if (dma_map) {
 269                 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
 270                                  DMA_BIDIRECTIONAL);
 271                 if (!nsg) {
 272                         eprintk("fail to map %p %d\n", iue, scsi_sg_count(sc));
 273                         err = -EIO;
 274                         goto free_mem;
 275                 }
 276                 len = min(scsi_bufflen(sc), id->len);
 277         } else
 278                 len = id->len;
 279
 280         err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
 281
 282         if (dma_map)
 283                 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
 284
 285 free_mem:
 286         if (token && dma_map)
 287                 dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
 288
 289         return err;
 290 }
 291
 292 static int data_out_desc_size(struct srp_cmd *cmd)
 293 {
 294         int size = 0;
 295         u8 fmt = cmd->buf_fmt >> 4;
 296
 297         switch (fmt) {
 298         case SRP_NO_DATA_DESC:
 299                 break;
 300         case SRP_DATA_DESC_DIRECT:
 301                 size = sizeof(struct srp_direct_buf);
 302                 break;
 303         case SRP_DATA_DESC_INDIRECT:
 304                 size = sizeof(struct srp_indirect_buf) +
 305                         sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
 306                 break;
 307         default:
 308                 eprintk("client error. Invalid data_out_format %x\n", fmt);
 309                 break;
 310         }
 311         return size;
 312 }
 313
 314 /*
 315  * TODO: this can be called multiple times for a single command if it
 316  * has very long data.
 317  */
 318 int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
 319                       srp_rdma_t rdma_io, int dma_map, int ext_desc)
 320 {
 321         struct srp_direct_buf *md;
 322         struct srp_indirect_buf *id;
 323         enum dma_data_direction dir;
 324         int offset, err = 0;
 325         u8 format;
 326
 327         offset = cmd->add_cdb_len * 4;
 328
 329         dir = srp_cmd_direction(cmd);
 330         if (dir == DMA_FROM_DEVICE)
 331                 offset += data_out_desc_size(cmd);
 332
 333         if (dir == DMA_TO_DEVICE)
 334                 format = cmd->buf_fmt >> 4;
 335         else
 336                 format = cmd->buf_fmt & ((1U << 4) - 1);
 337
 338         switch (format) {
 339         case SRP_NO_DATA_DESC:
 340                 break;
 341         case SRP_DATA_DESC_DIRECT:
 342                 md = (struct srp_direct_buf *)
 343                         (cmd->add_data + offset);
 344                 err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
 345                 break;
 346         case SRP_DATA_DESC_INDIRECT:
 347                 id = (struct srp_indirect_buf *)
 348                         (cmd->add_data + offset);
 349                 err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
 350                                         ext_desc);
 351                 break;
 352         default:
 353                 eprintk("Unknown format %d %x\n", dir, format);
 354                 err = -EINVAL;
 355         }
 356
 357         return err;
 358 }
 359 EXPORT_SYMBOL_GPL(srp_transfer_data);
 360
 361 static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
 362 {
 363         struct srp_direct_buf *md;
 364         struct srp_indirect_buf *id;
 365         int len = 0, offset = cmd->add_cdb_len * 4;
 366         u8 fmt;
 367
 368         if (dir == DMA_TO_DEVICE)
 369                 fmt = cmd->buf_fmt >> 4;
 370         else {
 371                 fmt = cmd->buf_fmt & ((1U << 4) - 1);
 372                 offset += data_out_desc_size(cmd);
 373         }
 374
 375         switch (fmt) {
 376         case SRP_NO_DATA_DESC:
 377                 break;
 378         case SRP_DATA_DESC_DIRECT:
 379                 md = (struct srp_direct_buf *) (cmd->add_data + offset);
 380                 len = md->len;
 381                 break;
 382         case SRP_DATA_DESC_INDIRECT:
 383                 id = (struct srp_indirect_buf *) (cmd->add_data + offset);
 384                 len = id->len;
 385                 break;
 386         default:
 387                 eprintk("invalid data format %x\n", fmt);
 388                 break;
 389         }
 390         return len;
 391 }
 392
 393 int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
 394                   u64 itn_id, u64 addr)
 395 {
 396         enum dma_data_direction dir;
 397         struct scsi_cmnd *sc;
 398         int tag, len, err;
 399
 400         switch (cmd->task_attr) {
 401         case SRP_SIMPLE_TASK:
 402                 tag = MSG_SIMPLE_TAG;
 403                 break;
 404         case SRP_ORDERED_TASK:
 405                 tag = MSG_ORDERED_TAG;
 406                 break;
 407         case SRP_HEAD_TASK:
 408                 tag = MSG_HEAD_TAG;
 409                 break;
 410         default:
 411                 eprintk("Task attribute %d not supported\n", cmd->task_attr);
 412                 tag = MSG_ORDERED_TAG;
 413         }
 414
 415         dir = srp_cmd_direction(cmd);
 416         len = vscsis_data_length(cmd, dir);
 417
 418         dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
 419                 cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
 420
 421         sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
 422         if (!sc)
 423                 return -ENOMEM;
 424
 425         sc->SCp.ptr = info;
 426         memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
 427         sc->sdb.length = len;
 428         sc->sdb.table.sgl = (void *) (unsigned long) addr;
 429         sc->tag = tag;
 430         err = scsi_tgt_queue_command(sc, itn_id, (struct scsi_lun *)&cmd->lun,
 431                                      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");