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 <linux/pci.h>
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_cmnd.h>
  28 #include <scsi/scsi_tcq.h>
  29 #include <scsi/scsi_tgt.h>
  30 #include <scsi/srp.h>
  31 #include <scsi/libsrp.h>
  32
  33 enum srp_task_attributes {
  34         SRP_SIMPLE_TASK = 0,
  35         SRP_HEAD_TASK = 1,
  36         SRP_ORDERED_TASK = 2,
  37         SRP_ACA_TASK = 4
  38 };
  39
  40 /* tmp - will replace with SCSI logging stuff */
  41 #define eprintk(fmt, args...)                                   \
  42 do {                                                            \
  43         printk("%s(%d) " fmt, __FUNCTION__, __LINE__, ##args);  \
  44 } while (0)
  45 /* #define dprintk eprintk */
  46 #define dprintk(fmt, args...)
  47
  48 static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
  49                              struct srp_buf **ring)
  50 {
  51         int i;
  52         struct iu_entry *iue;
  53
  54         q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
  55         if (!q->pool)
  56                 return -ENOMEM;
  57         q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
  58         if (!q->items)
  59                 goto free_pool;
  60
  61         spin_lock_init(&q->lock);
  62         q->queue = kfifo_init((void *) q->pool, max * sizeof(void *),
  63                               GFP_KERNEL, &q->lock);
  64         if (IS_ERR(q->queue))
  65                 goto free_item;
  66
  67         for (i = 0, iue = q->items; i < max; i++) {
  68                 __kfifo_put(q->queue, (void *) &iue, sizeof(void *));
  69                 iue->sbuf = ring[i];
  70                 iue++;
  71         }
  72         return 0;
  73
  74 free_item:
  75         kfree(q->items);
  76 free_pool:
  77         kfree(q->pool);
  78         return -ENOMEM;
  79 }
  80
  81 static void srp_iu_pool_free(struct srp_queue *q)
  82 {
  83         kfree(q->items);
  84         kfree(q->pool);
  85 }
  86
  87 static struct srp_buf **srp_ring_alloc(struct device *dev,
  88                                        size_t max, size_t size)
  89 {
  90         int i;
  91         struct srp_buf **ring;
  92
  93         ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
  94         if (!ring)
  95                 return NULL;
  96
  97         for (i = 0; i < max; i++) {
  98                 ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
  99                 if (!ring[i])
 100                         goto out;
 101                 ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
 102                                                   GFP_KERNEL);
 103                 if (!ring[i]->buf)
 104                         goto out;
 105         }
 106         return ring;
 107
 108 out:
 109         for (i = 0; i < max && ring[i]; i++) {
 110                 if (ring[i]->buf)
 111                         dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
 112                 kfree(ring[i]);
 113         }
 114         kfree(ring);
 115
 116         return NULL;
 117 }
 118
 119 static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
 120                           size_t size)
 121 {
 122         int i;
 123
 124         for (i = 0; i < max; i++) {
 125                 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
 126                 kfree(ring[i]);
 127         }
 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         target->dev->driver_data = 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 = sc->request_buffer;
 197
 198                 dprintk("%p %u %u %d\n", iue, sc->request_bufflen,
 199                         md->len, sc->use_sg);
 200
 201                 nsg = dma_map_sg(iue->target->dev, sg, sc->use_sg,
 202                                  DMA_BIDIRECTIONAL);
 203                 if (!nsg) {
 204                         printk("fail to map %p %d\n", iue, sc->use_sg);
 205                         return 0;
 206                 }
 207                 len = min(sc->request_bufflen, 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         long err;
 229         unsigned int done = 0;
 230         int nmd, nsg = 0, len;
 231
 232         if (dma_map || ext_desc) {
 233                 iue = (struct iu_entry *) sc->SCp.ptr;
 234                 sg = sc->request_buffer;
 235
 236                 dprintk("%p %u %u %d %d\n",
 237                         iue, sc->request_bufflen, id->len,
 238                         cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
 239         }
 240
 241         nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
 242
 243         if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
 244             (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
 245                 md = &id->desc_list[0];
 246                 goto rdma;
 247         }
 248
 249         if (ext_desc && dma_map) {
 250                 md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
 251                                 &token, GFP_KERNEL);
 252                 if (!md) {
 253                         eprintk("Can't get dma memory %u\n", id->table_desc.len);
 254                         return -ENOMEM;
 255                 }
 256
 257                 sg_init_one(&dummy, md, id->table_desc.len);
 258                 sg_dma_address(&dummy) = token;
 259                 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
 260                               id->table_desc.len);
 261                 if (err < 0) {
 262                         eprintk("Error copying indirect table %ld\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, sc->use_sg, DMA_BIDIRECTIONAL);
 273                 if (!nsg) {
 274                         eprintk("fail to map %p %d\n", iue, sc->use_sg);
 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 done;
 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                 break;
 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");