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         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         kfree(ring);
 128 }
 129
 130 int srp_target_alloc(struct srp_target *target, struct device *dev,
 131                      size_t nr, size_t iu_size)
 132 {
 133         int err;
 134
 135         spin_lock_init(&target->lock);
 136         INIT_LIST_HEAD(&target->cmd_queue);
 137
 138         target->dev = dev;
 139         dev_set_drvdata(target->dev, target);
 140
 141         target->srp_iu_size = iu_size;
 142         target->rx_ring_size = nr;
 143         target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
 144         if (!target->rx_ring)
 145                 return -ENOMEM;
 146         err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
 147         if (err)
 148                 goto free_ring;
 149
 150         return 0;
 151
 152 free_ring:
 153         srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
 154         return -ENOMEM;
 155 }
 156 EXPORT_SYMBOL_GPL(srp_target_alloc);
 157
 158 void srp_target_free(struct srp_target *target)
 159 {
 160         srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
 161                       target->srp_iu_size);
 162         srp_iu_pool_free(&target->iu_queue);
 163 }
 164 EXPORT_SYMBOL_GPL(srp_target_free);
 165
 166 struct iu_entry *srp_iu_get(struct srp_target *target)
 167 {
 168         struct iu_entry *iue = NULL;
 169
 170         kfifo_get(target->iu_queue.queue, (void *) &iue, sizeof(void *));
 171         if (!iue)
 172                 return iue;
 173         iue->target = target;
 174         INIT_LIST_HEAD(&iue->ilist);
 175         iue->flags = 0;
 176         return iue;
 177 }
 178 EXPORT_SYMBOL_GPL(srp_iu_get);
 179
 180 void srp_iu_put(struct iu_entry *iue)
 181 {
 182         kfifo_put(iue->target->iu_queue.queue, (void *) &iue, sizeof(void *));
 183 }
 184 EXPORT_SYMBOL_GPL(srp_iu_put);
 185
 186 static int srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
 187                            enum dma_data_direction dir, srp_rdma_t rdma_io,
 188                            int dma_map, int ext_desc)
 189 {
 190         struct iu_entry *iue = NULL;
 191         struct scatterlist *sg = NULL;
 192         int err, nsg = 0, len;
 193
 194         if (dma_map) {
 195                 iue = (struct iu_entry *) sc->SCp.ptr;
 196                 sg = scsi_sglist(sc);
 197
 198                 dprintk("%p %u %u %d\n", iue, scsi_bufflen(sc),
 199                         md->len, scsi_sg_count(sc));
 200
 201                 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
 202                                  DMA_BIDIRECTIONAL);
 203                 if (!nsg) {
 204                         printk("fail to map %p %d\n", iue, scsi_sg_count(sc));
 205                         return 0;
 206                 }
 207                 len = min(scsi_bufflen(sc), md->len);
 208         } else
 209                 len = md->len;
 210
 211         err = rdma_io(sc, sg, nsg, md, 1, dir, len);
 212
 213         if (dma_map)
 214                 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
 215
 216         return err;
 217 }
 218
 219 static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
 220                              struct srp_indirect_buf *id,
 221                              enum dma_data_direction dir, srp_rdma_t rdma_io,
 222                              int dma_map, int ext_desc)
 223 {
 224         struct iu_entry *iue = NULL;
 225         struct srp_direct_buf *md = NULL;
 226         struct scatterlist dummy, *sg = NULL;
 227         dma_addr_t token = 0;
 228         int err = 0;
 229         int nmd, nsg = 0, len;
 230
 231         if (dma_map || ext_desc) {
 232                 iue = (struct iu_entry *) sc->SCp.ptr;
 233                 sg = scsi_sglist(sc);
 234
 235                 dprintk("%p %u %u %d %d\n",
 236                         iue, scsi_bufflen(sc), id->len,
 237                         cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
 238         }
 239
 240         nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
 241
 242         if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
 243             (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
 244                 md = &id->desc_list[0];
 245                 goto rdma;
 246         }
 247
 248         if (ext_desc && dma_map) {
 249                 md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
 250                                 &token, GFP_KERNEL);
 251                 if (!md) {
 252                         eprintk("Can't get dma memory %u\n", id->table_desc.len);
 253                         return -ENOMEM;
 254                 }
 255
 256                 sg_init_one(&dummy, md, id->table_desc.len);
 257                 sg_dma_address(&dummy) = token;
 258                 sg_dma_len(&dummy) = id->table_desc.len;
 259                 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
 260                               id->table_desc.len);
 261                 if (err) {
 262                         eprintk("Error copying indirect table %d\n", err);
 263                         goto free_mem;
 264                 }
 265         } else {
 266                 eprintk("This command uses external indirect buffer\n");
 267                 return -EINVAL;
 268         }
 269
 270 rdma:
 271         if (dma_map) {
 272                 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
 273                                  DMA_BIDIRECTIONAL);
 274                 if (!nsg) {
 275                         eprintk("fail to map %p %d\n", iue, scsi_sg_count(sc));
 276                         err = -EIO;
 277                         goto free_mem;
 278                 }
 279                 len = min(scsi_bufflen(sc), id->len);
 280         } else
 281                 len = id->len;
 282
 283         err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
 284
 285         if (dma_map)
 286                 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
 287
 288 free_mem:
 289         if (token && dma_map)
 290                 dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
 291
 292         return err;
 293 }
 294
 295 static int data_out_desc_size(struct srp_cmd *cmd)
 296 {
 297         int size = 0;
 298         u8 fmt = cmd->buf_fmt >> 4;
 299
 300         switch (fmt) {
 301         case SRP_NO_DATA_DESC:
 302                 break;
 303         case SRP_DATA_DESC_DIRECT:
 304                 size = sizeof(struct srp_direct_buf);
 305                 break;
 306         case SRP_DATA_DESC_INDIRECT:
 307                 size = sizeof(struct srp_indirect_buf) +
 308                         sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
 309                 break;
 310         default:
 311                 eprintk("client error. Invalid data_out_format %x\n", fmt);
 312                 break;
 313         }
 314         return size;
 315 }
 316
 317 /*
 318  * TODO: this can be called multiple times for a single command if it
 319  * has very long data.
 320  */
 321 int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
 322                       srp_rdma_t rdma_io, int dma_map, int ext_desc)
 323 {
 324         struct srp_direct_buf *md;
 325         struct srp_indirect_buf *id;
 326         enum dma_data_direction dir;
 327         int offset, err = 0;
 328         u8 format;
 329
 330         offset = cmd->add_cdb_len * 4;
 331
 332         dir = srp_cmd_direction(cmd);
 333         if (dir == DMA_FROM_DEVICE)
 334                 offset += data_out_desc_size(cmd);
 335
 336         if (dir == DMA_TO_DEVICE)
 337                 format = cmd->buf_fmt >> 4;
 338         else
 339                 format = cmd->buf_fmt & ((1U << 4) - 1);
 340
 341         switch (format) {
 342         case SRP_NO_DATA_DESC:
 343                 break;
 344         case SRP_DATA_DESC_DIRECT:
 345                 md = (struct srp_direct_buf *)
 346                         (cmd->add_data + offset);
 347                 err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
 348                 break;
 349         case SRP_DATA_DESC_INDIRECT:
 350                 id = (struct srp_indirect_buf *)
 351                         (cmd->add_data + offset);
 352                 err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
 353                                         ext_desc);
 354                 break;
 355         default:
 356                 eprintk("Unknown format %d %x\n", dir, format);
 357                 err = -EINVAL;
 358         }
 359
 360         return err;
 361 }
 362 EXPORT_SYMBOL_GPL(srp_transfer_data);
 363
 364 static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
 365 {
 366         struct srp_direct_buf *md;
 367         struct srp_indirect_buf *id;
 368         int len = 0, offset = cmd->add_cdb_len * 4;
 369         u8 fmt;
 370
 371         if (dir == DMA_TO_DEVICE)
 372                 fmt = cmd->buf_fmt >> 4;
 373         else {
 374                 fmt = cmd->buf_fmt & ((1U << 4) - 1);
 375                 offset += data_out_desc_size(cmd);
 376         }
 377
 378         switch (fmt) {
 379         case SRP_NO_DATA_DESC:
 380                 break;
 381         case SRP_DATA_DESC_DIRECT:
 382                 md = (struct srp_direct_buf *) (cmd->add_data + offset);
 383                 len = md->len;
 384                 break;
 385         case SRP_DATA_DESC_INDIRECT:
 386                 id = (struct srp_indirect_buf *) (cmd->add_data + offset);
 387                 len = id->len;
 388                 break;
 389         default:
 390                 eprintk("invalid data format %x\n", fmt);
 391                 break;
 392         }
 393         return len;
 394 }
 395
 396 int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
 397                   u64 itn_id, u64 addr)
 398 {
 399         enum dma_data_direction dir;
 400         struct scsi_cmnd *sc;
 401         int tag, len, err;
 402
 403         switch (cmd->task_attr) {
 404         case SRP_SIMPLE_TASK:
 405                 tag = MSG_SIMPLE_TAG;
 406                 break;
 407         case SRP_ORDERED_TASK:
 408                 tag = MSG_ORDERED_TAG;
 409                 break;
 410         case SRP_HEAD_TASK:
 411                 tag = MSG_HEAD_TAG;
 412                 break;
 413         default:
 414                 eprintk("Task attribute %d not supported\n", cmd->task_attr);
 415                 tag = MSG_ORDERED_TAG;
 416         }
 417
 418         dir = srp_cmd_direction(cmd);
 419         len = vscsis_data_length(cmd, dir);
 420
 421         dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
 422                 cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
 423
 424         sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
 425         if (!sc)
 426                 return -ENOMEM;
 427
 428         sc->SCp.ptr = info;
 429         memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
 430         sc->sdb.length = len;
 431         sc->sdb.table.sgl = (void *) (unsigned long) addr;
 432         sc->tag = tag;
 433         err = scsi_tgt_queue_command(sc, itn_id, (struct scsi_lun *)&cmd->lun,
 434                                      cmd->tag);
 435         if (err)
 436                 scsi_host_put_command(shost, sc);
 437
 438         return err;
 439 }
 440 EXPORT_SYMBOL_GPL(srp_cmd_queue);
 441
 442 MODULE_DESCRIPTION("SCSI RDAM Protocol lib functions");
 443 MODULE_AUTHOR("FUJITA Tomonori");
 444 MODULE_LICENSE("GPL");