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                 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
 258                               id->table_desc.len);
 259                 if (err) {
 260                         eprintk("Error copying indirect table %d\n", err);
 261                         goto free_mem;
 262                 }
 263         } else {
 264                 eprintk("This command uses external indirect buffer\n");
 265                 return -EINVAL;
 266         }
 267
 268 rdma:
 269         if (dma_map) {
 270                 nsg = dma_map_sg(iue->target->dev, sg, sc->use_sg, DMA_BIDIRECTIONAL);
 271                 if (!nsg) {
 272                         eprintk("fail to map %p %d\n", iue, sc->use_sg);
 273                         err = -EIO;
 274                         goto free_mem;
 275                 }
 276                 len = min(sc->request_bufflen, 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 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->request_bufflen = len;
 428         sc->request_buffer = (void *) (unsigned long) addr;
 429         sc->tag = tag;
 430         err = scsi_tgt_queue_command(sc, (struct scsi_lun *) &cmd->lun, cmd->tag);
 431         if (err)
 432                 scsi_host_put_command(shost, sc);
 433
 434         return err;
 435 }
 436 EXPORT_SYMBOL_GPL(srp_cmd_queue);
 437
 438 MODULE_DESCRIPTION("SCSI RDAM Protocol lib functions");
 439 MODULE_AUTHOR("FUJITA Tomonori");
 440 MODULE_LICENSE("GPL");