Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 Shaohua Li <shli@kernel.org> |
| 3 | * Copyright (C) 2014 Red Hat, Inc. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms and conditions of the GNU General Public License, |
| 7 | * version 2, as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along with |
| 15 | * this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/idr.h> |
| 22 | #include <linux/timer.h> |
| 23 | #include <linux/parser.h> |
| 24 | #include <scsi/scsi.h> |
| 25 | #include <scsi/scsi_host.h> |
| 26 | #include <linux/uio_driver.h> |
| 27 | #include <net/genetlink.h> |
| 28 | #include <target/target_core_base.h> |
| 29 | #include <target/target_core_fabric.h> |
| 30 | #include <target/target_core_backend.h> |
| 31 | #include <linux/target_core_user.h> |
| 32 | |
| 33 | /* |
| 34 | * Define a shared-memory interface for LIO to pass SCSI commands and |
| 35 | * data to userspace for processing. This is to allow backends that |
| 36 | * are too complex for in-kernel support to be possible. |
| 37 | * |
| 38 | * It uses the UIO framework to do a lot of the device-creation and |
| 39 | * introspection work for us. |
| 40 | * |
| 41 | * See the .h file for how the ring is laid out. Note that while the |
| 42 | * command ring is defined, the particulars of the data area are |
| 43 | * not. Offset values in the command entry point to other locations |
| 44 | * internal to the mmap()ed area. There is separate space outside the |
| 45 | * command ring for data buffers. This leaves maximum flexibility for |
| 46 | * moving buffer allocations, or even page flipping or other |
| 47 | * allocation techniques, without altering the command ring layout. |
| 48 | * |
| 49 | * SECURITY: |
| 50 | * The user process must be assumed to be malicious. There's no way to |
| 51 | * prevent it breaking the command ring protocol if it wants, but in |
| 52 | * order to prevent other issues we must only ever read *data* from |
| 53 | * the shared memory area, not offsets or sizes. This applies to |
| 54 | * command ring entries as well as the mailbox. Extra code needed for |
| 55 | * this may have a 'UAM' comment. |
| 56 | */ |
| 57 | |
| 58 | |
| 59 | #define TCMU_TIME_OUT (30 * MSEC_PER_SEC) |
| 60 | |
| 61 | #define CMDR_SIZE (16 * 4096) |
| 62 | #define DATA_SIZE (257 * 4096) |
| 63 | |
| 64 | #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE) |
| 65 | |
| 66 | static struct device *tcmu_root_device; |
| 67 | |
| 68 | struct tcmu_hba { |
| 69 | u32 host_id; |
| 70 | }; |
| 71 | |
| 72 | /* User wants all cmds or just some */ |
| 73 | enum passthru_level { |
| 74 | TCMU_PASS_ALL = 0, |
| 75 | TCMU_PASS_IO, |
| 76 | TCMU_PASS_INVALID, |
| 77 | }; |
| 78 | |
| 79 | #define TCMU_CONFIG_LEN 256 |
| 80 | |
| 81 | struct tcmu_dev { |
| 82 | struct se_device se_dev; |
| 83 | |
| 84 | char *name; |
| 85 | struct se_hba *hba; |
| 86 | |
| 87 | #define TCMU_DEV_BIT_OPEN 0 |
| 88 | #define TCMU_DEV_BIT_BROKEN 1 |
| 89 | unsigned long flags; |
| 90 | enum passthru_level pass_level; |
| 91 | |
| 92 | struct uio_info uio_info; |
| 93 | |
| 94 | struct tcmu_mailbox *mb_addr; |
| 95 | size_t dev_size; |
| 96 | u32 cmdr_size; |
| 97 | u32 cmdr_last_cleaned; |
| 98 | /* Offset of data ring from start of mb */ |
| 99 | size_t data_off; |
| 100 | size_t data_size; |
| 101 | /* Ring head + tail values. */ |
| 102 | /* Must add data_off and mb_addr to get the address */ |
| 103 | size_t data_head; |
| 104 | size_t data_tail; |
| 105 | |
| 106 | wait_queue_head_t wait_cmdr; |
| 107 | /* TODO should this be a mutex? */ |
| 108 | spinlock_t cmdr_lock; |
| 109 | |
| 110 | struct idr commands; |
| 111 | spinlock_t commands_lock; |
| 112 | |
| 113 | struct timer_list timeout; |
| 114 | |
| 115 | char dev_config[TCMU_CONFIG_LEN]; |
| 116 | }; |
| 117 | |
| 118 | #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev) |
| 119 | |
| 120 | #define CMDR_OFF sizeof(struct tcmu_mailbox) |
| 121 | |
| 122 | struct tcmu_cmd { |
| 123 | struct se_cmd *se_cmd; |
| 124 | struct tcmu_dev *tcmu_dev; |
| 125 | |
| 126 | uint16_t cmd_id; |
| 127 | |
| 128 | /* Can't use se_cmd->data_length when cleaning up expired cmds, because if |
| 129 | cmd has been completed then accessing se_cmd is off limits */ |
| 130 | size_t data_length; |
| 131 | |
| 132 | unsigned long deadline; |
| 133 | |
| 134 | #define TCMU_CMD_BIT_EXPIRED 0 |
| 135 | unsigned long flags; |
| 136 | }; |
| 137 | |
| 138 | static struct kmem_cache *tcmu_cmd_cache; |
| 139 | |
| 140 | /* multicast group */ |
| 141 | enum tcmu_multicast_groups { |
| 142 | TCMU_MCGRP_CONFIG, |
| 143 | }; |
| 144 | |
| 145 | static const struct genl_multicast_group tcmu_mcgrps[] = { |
| 146 | [TCMU_MCGRP_CONFIG] = { .name = "config", }, |
| 147 | }; |
| 148 | |
| 149 | /* Our generic netlink family */ |
| 150 | static struct genl_family tcmu_genl_family = { |
| 151 | .id = GENL_ID_GENERATE, |
| 152 | .hdrsize = 0, |
| 153 | .name = "TCM-USER", |
| 154 | .version = 1, |
| 155 | .maxattr = TCMU_ATTR_MAX, |
| 156 | .mcgrps = tcmu_mcgrps, |
| 157 | .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps), |
| 158 | }; |
| 159 | |
| 160 | static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd) |
| 161 | { |
| 162 | struct se_device *se_dev = se_cmd->se_dev; |
| 163 | struct tcmu_dev *udev = TCMU_DEV(se_dev); |
| 164 | struct tcmu_cmd *tcmu_cmd; |
| 165 | int cmd_id; |
| 166 | |
| 167 | tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL); |
| 168 | if (!tcmu_cmd) |
| 169 | return NULL; |
| 170 | |
| 171 | tcmu_cmd->se_cmd = se_cmd; |
| 172 | tcmu_cmd->tcmu_dev = udev; |
| 173 | tcmu_cmd->data_length = se_cmd->data_length; |
| 174 | |
| 175 | tcmu_cmd->deadline = jiffies + msecs_to_jiffies(TCMU_TIME_OUT); |
| 176 | |
| 177 | idr_preload(GFP_KERNEL); |
| 178 | spin_lock_irq(&udev->commands_lock); |
| 179 | cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 0, |
| 180 | USHRT_MAX, GFP_NOWAIT); |
| 181 | spin_unlock_irq(&udev->commands_lock); |
| 182 | idr_preload_end(); |
| 183 | |
| 184 | if (cmd_id < 0) { |
| 185 | kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); |
| 186 | return NULL; |
| 187 | } |
| 188 | tcmu_cmd->cmd_id = cmd_id; |
| 189 | |
| 190 | return tcmu_cmd; |
| 191 | } |
| 192 | |
| 193 | static inline void tcmu_flush_dcache_range(void *vaddr, size_t size) |
| 194 | { |
| 195 | unsigned long offset = (unsigned long) vaddr & ~PAGE_MASK; |
| 196 | |
| 197 | size = round_up(size+offset, PAGE_SIZE); |
| 198 | vaddr -= offset; |
| 199 | |
| 200 | while (size) { |
| 201 | flush_dcache_page(virt_to_page(vaddr)); |
| 202 | size -= PAGE_SIZE; |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * Some ring helper functions. We don't assume size is a power of 2 so |
| 208 | * we can't use circ_buf.h. |
| 209 | */ |
| 210 | static inline size_t spc_used(size_t head, size_t tail, size_t size) |
| 211 | { |
| 212 | int diff = head - tail; |
| 213 | |
| 214 | if (diff >= 0) |
| 215 | return diff; |
| 216 | else |
| 217 | return size + diff; |
| 218 | } |
| 219 | |
| 220 | static inline size_t spc_free(size_t head, size_t tail, size_t size) |
| 221 | { |
| 222 | /* Keep 1 byte unused or we can't tell full from empty */ |
| 223 | return (size - spc_used(head, tail, size) - 1); |
| 224 | } |
| 225 | |
| 226 | static inline size_t head_to_end(size_t head, size_t size) |
| 227 | { |
| 228 | return size - head; |
| 229 | } |
| 230 | |
| 231 | #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size) |
| 232 | |
| 233 | /* |
| 234 | * We can't queue a command until we have space available on the cmd ring *and* space |
| 235 | * space avail on the data ring. |
| 236 | * |
| 237 | * Called with ring lock held. |
| 238 | */ |
Andy Grover | f56574a | 2014-10-02 10:23:15 -0700 | [diff] [blame^] | 239 | static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t data_needed) |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 240 | { |
| 241 | struct tcmu_mailbox *mb = udev->mb_addr; |
| 242 | size_t space; |
| 243 | u32 cmd_head; |
Andy Grover | f56574a | 2014-10-02 10:23:15 -0700 | [diff] [blame^] | 244 | size_t cmd_needed; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 245 | |
| 246 | tcmu_flush_dcache_range(mb, sizeof(*mb)); |
| 247 | |
| 248 | cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ |
| 249 | |
Andy Grover | f56574a | 2014-10-02 10:23:15 -0700 | [diff] [blame^] | 250 | /* |
| 251 | * If cmd end-of-ring space is too small then we need space for a NOP plus |
| 252 | * original cmd - cmds are internally contiguous. |
| 253 | */ |
| 254 | if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size) |
| 255 | cmd_needed = cmd_size; |
| 256 | else |
| 257 | cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size); |
| 258 | |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 259 | space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size); |
| 260 | if (space < cmd_needed) { |
| 261 | pr_debug("no cmd space: %u %u %u\n", cmd_head, |
| 262 | udev->cmdr_last_cleaned, udev->cmdr_size); |
| 263 | return false; |
| 264 | } |
| 265 | |
| 266 | space = spc_free(udev->data_head, udev->data_tail, udev->data_size); |
| 267 | if (space < data_needed) { |
| 268 | pr_debug("no data space: %zu %zu %zu\n", udev->data_head, |
| 269 | udev->data_tail, udev->data_size); |
| 270 | return false; |
| 271 | } |
| 272 | |
| 273 | return true; |
| 274 | } |
| 275 | |
| 276 | static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd) |
| 277 | { |
| 278 | struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; |
| 279 | struct se_cmd *se_cmd = tcmu_cmd->se_cmd; |
| 280 | size_t base_command_size, command_size; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 281 | struct tcmu_mailbox *mb; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 282 | struct tcmu_cmd_entry *entry; |
| 283 | int i; |
| 284 | struct scatterlist *sg; |
| 285 | struct iovec *iov; |
| 286 | int iov_cnt = 0; |
| 287 | uint32_t cmd_head; |
| 288 | uint64_t cdb_off; |
| 289 | |
| 290 | if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) |
| 291 | return -EINVAL; |
| 292 | |
| 293 | /* |
| 294 | * Must be a certain minimum size for response sense info, but |
| 295 | * also may be larger if the iov array is large. |
| 296 | * |
| 297 | * iovs = sgl_nents+1, for end-of-ring case, plus another 1 |
| 298 | * b/c size == offsetof one-past-element. |
| 299 | */ |
| 300 | base_command_size = max(offsetof(struct tcmu_cmd_entry, |
| 301 | req.iov[se_cmd->t_data_nents + 2]), |
| 302 | sizeof(struct tcmu_cmd_entry)); |
| 303 | command_size = base_command_size |
| 304 | + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE); |
| 305 | |
| 306 | WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1)); |
| 307 | |
| 308 | spin_lock_irq(&udev->cmdr_lock); |
| 309 | |
| 310 | mb = udev->mb_addr; |
| 311 | cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ |
| 312 | if ((command_size > (udev->cmdr_size / 2)) |
| 313 | || tcmu_cmd->data_length > (udev->data_size - 1)) |
| 314 | pr_warn("TCMU: Request of size %zu/%zu may be too big for %u/%zu " |
| 315 | "cmd/data ring buffers\n", command_size, tcmu_cmd->data_length, |
| 316 | udev->cmdr_size, udev->data_size); |
| 317 | |
Andy Grover | f56574a | 2014-10-02 10:23:15 -0700 | [diff] [blame^] | 318 | while (!is_ring_space_avail(udev, command_size, tcmu_cmd->data_length)) { |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 319 | int ret; |
| 320 | DEFINE_WAIT(__wait); |
| 321 | |
| 322 | prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE); |
| 323 | |
| 324 | pr_debug("sleeping for ring space\n"); |
| 325 | spin_unlock_irq(&udev->cmdr_lock); |
| 326 | ret = schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT)); |
| 327 | finish_wait(&udev->wait_cmdr, &__wait); |
| 328 | if (!ret) { |
| 329 | pr_warn("tcmu: command timed out\n"); |
| 330 | return -ETIMEDOUT; |
| 331 | } |
| 332 | |
| 333 | spin_lock_irq(&udev->cmdr_lock); |
| 334 | |
| 335 | /* We dropped cmdr_lock, cmd_head is stale */ |
| 336 | cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ |
| 337 | } |
| 338 | |
Andy Grover | f56574a | 2014-10-02 10:23:15 -0700 | [diff] [blame^] | 339 | /* Insert a PAD if end-of-ring space is too small */ |
| 340 | if (head_to_end(cmd_head, udev->cmdr_size) < command_size) { |
| 341 | size_t pad_size = head_to_end(cmd_head, udev->cmdr_size); |
| 342 | |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 343 | entry = (void *) mb + CMDR_OFF + cmd_head; |
| 344 | tcmu_flush_dcache_range(entry, sizeof(*entry)); |
| 345 | tcmu_hdr_set_op(&entry->hdr, TCMU_OP_PAD); |
| 346 | tcmu_hdr_set_len(&entry->hdr, pad_size); |
| 347 | |
| 348 | UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size); |
| 349 | |
| 350 | cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */ |
| 351 | WARN_ON(cmd_head != 0); |
| 352 | } |
| 353 | |
| 354 | entry = (void *) mb + CMDR_OFF + cmd_head; |
| 355 | tcmu_flush_dcache_range(entry, sizeof(*entry)); |
| 356 | tcmu_hdr_set_op(&entry->hdr, TCMU_OP_CMD); |
| 357 | tcmu_hdr_set_len(&entry->hdr, command_size); |
| 358 | entry->cmd_id = tcmu_cmd->cmd_id; |
| 359 | |
| 360 | /* |
| 361 | * Fix up iovecs, and handle if allocation in data ring wrapped. |
| 362 | */ |
| 363 | iov = &entry->req.iov[0]; |
| 364 | for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) { |
| 365 | size_t copy_bytes = min((size_t)sg->length, |
| 366 | head_to_end(udev->data_head, udev->data_size)); |
| 367 | void *from = kmap_atomic(sg_page(sg)) + sg->offset; |
| 368 | void *to = (void *) mb + udev->data_off + udev->data_head; |
| 369 | |
| 370 | if (tcmu_cmd->se_cmd->data_direction == DMA_TO_DEVICE) { |
| 371 | memcpy(to, from, copy_bytes); |
| 372 | tcmu_flush_dcache_range(to, copy_bytes); |
| 373 | } |
| 374 | |
| 375 | /* Even iov_base is relative to mb_addr */ |
| 376 | iov->iov_len = copy_bytes; |
| 377 | iov->iov_base = (void *) udev->data_off + udev->data_head; |
| 378 | iov_cnt++; |
| 379 | iov++; |
| 380 | |
| 381 | UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size); |
| 382 | |
| 383 | /* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */ |
| 384 | if (sg->length != copy_bytes) { |
| 385 | from += copy_bytes; |
| 386 | copy_bytes = sg->length - copy_bytes; |
| 387 | |
| 388 | iov->iov_len = copy_bytes; |
| 389 | iov->iov_base = (void *) udev->data_off + udev->data_head; |
| 390 | |
| 391 | if (se_cmd->data_direction == DMA_TO_DEVICE) { |
| 392 | to = (void *) mb + udev->data_off + udev->data_head; |
| 393 | memcpy(to, from, copy_bytes); |
| 394 | tcmu_flush_dcache_range(to, copy_bytes); |
| 395 | } |
| 396 | |
| 397 | iov_cnt++; |
| 398 | iov++; |
| 399 | |
| 400 | UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size); |
| 401 | } |
| 402 | |
| 403 | kunmap_atomic(from); |
| 404 | } |
| 405 | entry->req.iov_cnt = iov_cnt; |
| 406 | |
| 407 | /* All offsets relative to mb_addr, not start of entry! */ |
| 408 | cdb_off = CMDR_OFF + cmd_head + base_command_size; |
| 409 | memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb)); |
| 410 | entry->req.cdb_off = cdb_off; |
| 411 | tcmu_flush_dcache_range(entry, sizeof(*entry)); |
| 412 | |
| 413 | UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size); |
| 414 | tcmu_flush_dcache_range(mb, sizeof(*mb)); |
| 415 | |
| 416 | spin_unlock_irq(&udev->cmdr_lock); |
| 417 | |
| 418 | /* TODO: only if FLUSH and FUA? */ |
| 419 | uio_event_notify(&udev->uio_info); |
| 420 | |
| 421 | mod_timer(&udev->timeout, |
| 422 | round_jiffies_up(jiffies + msecs_to_jiffies(TCMU_TIME_OUT))); |
| 423 | |
| 424 | return 0; |
| 425 | } |
| 426 | |
| 427 | static int tcmu_queue_cmd(struct se_cmd *se_cmd) |
| 428 | { |
| 429 | struct se_device *se_dev = se_cmd->se_dev; |
| 430 | struct tcmu_dev *udev = TCMU_DEV(se_dev); |
| 431 | struct tcmu_cmd *tcmu_cmd; |
| 432 | int ret; |
| 433 | |
| 434 | tcmu_cmd = tcmu_alloc_cmd(se_cmd); |
| 435 | if (!tcmu_cmd) |
| 436 | return -ENOMEM; |
| 437 | |
| 438 | ret = tcmu_queue_cmd_ring(tcmu_cmd); |
| 439 | if (ret < 0) { |
| 440 | pr_err("TCMU: Could not queue command\n"); |
| 441 | spin_lock_irq(&udev->commands_lock); |
| 442 | idr_remove(&udev->commands, tcmu_cmd->cmd_id); |
| 443 | spin_unlock_irq(&udev->commands_lock); |
| 444 | |
| 445 | kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); |
| 446 | } |
| 447 | |
| 448 | return ret; |
| 449 | } |
| 450 | |
| 451 | static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry) |
| 452 | { |
| 453 | struct se_cmd *se_cmd = cmd->se_cmd; |
| 454 | struct tcmu_dev *udev = cmd->tcmu_dev; |
| 455 | |
| 456 | if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) { |
| 457 | /* cmd has been completed already from timeout, just reclaim data |
| 458 | ring space */ |
| 459 | UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size); |
| 460 | return; |
| 461 | } |
| 462 | |
| 463 | if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) { |
| 464 | memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer, |
| 465 | se_cmd->scsi_sense_length); |
| 466 | |
| 467 | UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size); |
| 468 | } |
| 469 | else if (se_cmd->data_direction == DMA_FROM_DEVICE) { |
| 470 | struct scatterlist *sg; |
| 471 | int i; |
| 472 | |
| 473 | /* It'd be easier to look at entry's iovec again, but UAM */ |
| 474 | for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) { |
| 475 | size_t copy_bytes; |
| 476 | void *to; |
| 477 | void *from; |
| 478 | |
| 479 | copy_bytes = min((size_t)sg->length, |
| 480 | head_to_end(udev->data_tail, udev->data_size)); |
| 481 | |
| 482 | to = kmap_atomic(sg_page(sg)) + sg->offset; |
| 483 | WARN_ON(sg->length + sg->offset > PAGE_SIZE); |
| 484 | from = (void *) udev->mb_addr + udev->data_off + udev->data_tail; |
| 485 | tcmu_flush_dcache_range(from, copy_bytes); |
| 486 | memcpy(to, from, copy_bytes); |
| 487 | |
| 488 | UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size); |
| 489 | |
| 490 | /* Uh oh, wrapped the data buffer for this sg's data */ |
| 491 | if (sg->length != copy_bytes) { |
| 492 | from = (void *) udev->mb_addr + udev->data_off + udev->data_tail; |
| 493 | WARN_ON(udev->data_tail); |
| 494 | to += copy_bytes; |
| 495 | copy_bytes = sg->length - copy_bytes; |
| 496 | tcmu_flush_dcache_range(from, copy_bytes); |
| 497 | memcpy(to, from, copy_bytes); |
| 498 | |
| 499 | UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size); |
| 500 | } |
| 501 | |
| 502 | kunmap_atomic(to); |
| 503 | } |
| 504 | |
| 505 | } else if (se_cmd->data_direction == DMA_TO_DEVICE) { |
| 506 | UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size); |
| 507 | } else { |
| 508 | pr_warn("TCMU: data direction was %d!\n", se_cmd->data_direction); |
| 509 | } |
| 510 | |
| 511 | target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status); |
| 512 | cmd->se_cmd = NULL; |
| 513 | |
| 514 | kmem_cache_free(tcmu_cmd_cache, cmd); |
| 515 | } |
| 516 | |
| 517 | static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) |
| 518 | { |
| 519 | struct tcmu_mailbox *mb; |
| 520 | LIST_HEAD(cpl_cmds); |
| 521 | unsigned long flags; |
| 522 | int handled = 0; |
| 523 | |
| 524 | if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) { |
| 525 | pr_err("ring broken, not handling completions\n"); |
| 526 | return 0; |
| 527 | } |
| 528 | |
| 529 | spin_lock_irqsave(&udev->cmdr_lock, flags); |
| 530 | |
| 531 | mb = udev->mb_addr; |
| 532 | tcmu_flush_dcache_range(mb, sizeof(*mb)); |
| 533 | |
| 534 | while (udev->cmdr_last_cleaned != ACCESS_ONCE(mb->cmd_tail)) { |
| 535 | |
| 536 | struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned; |
| 537 | struct tcmu_cmd *cmd; |
| 538 | |
| 539 | tcmu_flush_dcache_range(entry, sizeof(*entry)); |
| 540 | |
| 541 | if (tcmu_hdr_get_op(&entry->hdr) == TCMU_OP_PAD) { |
| 542 | UPDATE_HEAD(udev->cmdr_last_cleaned, tcmu_hdr_get_len(&entry->hdr), udev->cmdr_size); |
| 543 | continue; |
| 544 | } |
| 545 | WARN_ON(tcmu_hdr_get_op(&entry->hdr) != TCMU_OP_CMD); |
| 546 | |
| 547 | spin_lock(&udev->commands_lock); |
| 548 | cmd = idr_find(&udev->commands, entry->cmd_id); |
| 549 | if (cmd) |
| 550 | idr_remove(&udev->commands, cmd->cmd_id); |
| 551 | spin_unlock(&udev->commands_lock); |
| 552 | |
| 553 | if (!cmd) { |
| 554 | pr_err("cmd_id not found, ring is broken\n"); |
| 555 | set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags); |
| 556 | break; |
| 557 | } |
| 558 | |
| 559 | tcmu_handle_completion(cmd, entry); |
| 560 | |
| 561 | UPDATE_HEAD(udev->cmdr_last_cleaned, tcmu_hdr_get_len(&entry->hdr), udev->cmdr_size); |
| 562 | |
| 563 | handled++; |
| 564 | } |
| 565 | |
| 566 | if (mb->cmd_tail == mb->cmd_head) |
| 567 | del_timer(&udev->timeout); /* no more pending cmds */ |
| 568 | |
| 569 | spin_unlock_irqrestore(&udev->cmdr_lock, flags); |
| 570 | |
| 571 | wake_up(&udev->wait_cmdr); |
| 572 | |
| 573 | return handled; |
| 574 | } |
| 575 | |
| 576 | static int tcmu_check_expired_cmd(int id, void *p, void *data) |
| 577 | { |
| 578 | struct tcmu_cmd *cmd = p; |
| 579 | |
| 580 | if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) |
| 581 | return 0; |
| 582 | |
| 583 | if (!time_after(cmd->deadline, jiffies)) |
| 584 | return 0; |
| 585 | |
| 586 | set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags); |
| 587 | target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION); |
| 588 | cmd->se_cmd = NULL; |
| 589 | |
| 590 | kmem_cache_free(tcmu_cmd_cache, cmd); |
| 591 | |
| 592 | return 0; |
| 593 | } |
| 594 | |
| 595 | static void tcmu_device_timedout(unsigned long data) |
| 596 | { |
| 597 | struct tcmu_dev *udev = (struct tcmu_dev *)data; |
| 598 | unsigned long flags; |
| 599 | int handled; |
| 600 | |
| 601 | handled = tcmu_handle_completions(udev); |
| 602 | |
| 603 | pr_warn("%d completions handled from timeout\n", handled); |
| 604 | |
| 605 | spin_lock_irqsave(&udev->commands_lock, flags); |
| 606 | idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL); |
| 607 | spin_unlock_irqrestore(&udev->commands_lock, flags); |
| 608 | |
| 609 | /* |
| 610 | * We don't need to wakeup threads on wait_cmdr since they have their |
| 611 | * own timeout. |
| 612 | */ |
| 613 | } |
| 614 | |
| 615 | static int tcmu_attach_hba(struct se_hba *hba, u32 host_id) |
| 616 | { |
| 617 | struct tcmu_hba *tcmu_hba; |
| 618 | |
| 619 | tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL); |
| 620 | if (!tcmu_hba) |
| 621 | return -ENOMEM; |
| 622 | |
| 623 | tcmu_hba->host_id = host_id; |
| 624 | hba->hba_ptr = tcmu_hba; |
| 625 | |
| 626 | return 0; |
| 627 | } |
| 628 | |
| 629 | static void tcmu_detach_hba(struct se_hba *hba) |
| 630 | { |
| 631 | kfree(hba->hba_ptr); |
| 632 | hba->hba_ptr = NULL; |
| 633 | } |
| 634 | |
| 635 | static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) |
| 636 | { |
| 637 | struct tcmu_dev *udev; |
| 638 | |
| 639 | udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL); |
| 640 | if (!udev) |
| 641 | return NULL; |
| 642 | |
| 643 | udev->name = kstrdup(name, GFP_KERNEL); |
| 644 | if (!udev->name) { |
| 645 | kfree(udev); |
| 646 | return NULL; |
| 647 | } |
| 648 | |
| 649 | udev->hba = hba; |
| 650 | |
| 651 | init_waitqueue_head(&udev->wait_cmdr); |
| 652 | spin_lock_init(&udev->cmdr_lock); |
| 653 | |
| 654 | idr_init(&udev->commands); |
| 655 | spin_lock_init(&udev->commands_lock); |
| 656 | |
| 657 | setup_timer(&udev->timeout, tcmu_device_timedout, |
| 658 | (unsigned long)udev); |
| 659 | |
| 660 | udev->pass_level = TCMU_PASS_ALL; |
| 661 | |
| 662 | return &udev->se_dev; |
| 663 | } |
| 664 | |
| 665 | static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on) |
| 666 | { |
| 667 | struct tcmu_dev *tcmu_dev = container_of(info, struct tcmu_dev, uio_info); |
| 668 | |
| 669 | tcmu_handle_completions(tcmu_dev); |
| 670 | |
| 671 | return 0; |
| 672 | } |
| 673 | |
| 674 | /* |
| 675 | * mmap code from uio.c. Copied here because we want to hook mmap() |
| 676 | * and this stuff must come along. |
| 677 | */ |
| 678 | static int tcmu_find_mem_index(struct vm_area_struct *vma) |
| 679 | { |
| 680 | struct tcmu_dev *udev = vma->vm_private_data; |
| 681 | struct uio_info *info = &udev->uio_info; |
| 682 | |
| 683 | if (vma->vm_pgoff < MAX_UIO_MAPS) { |
| 684 | if (info->mem[vma->vm_pgoff].size == 0) |
| 685 | return -1; |
| 686 | return (int)vma->vm_pgoff; |
| 687 | } |
| 688 | return -1; |
| 689 | } |
| 690 | |
| 691 | static int tcmu_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 692 | { |
| 693 | struct tcmu_dev *udev = vma->vm_private_data; |
| 694 | struct uio_info *info = &udev->uio_info; |
| 695 | struct page *page; |
| 696 | unsigned long offset; |
| 697 | void *addr; |
| 698 | |
| 699 | int mi = tcmu_find_mem_index(vma); |
| 700 | if (mi < 0) |
| 701 | return VM_FAULT_SIGBUS; |
| 702 | |
| 703 | /* |
| 704 | * We need to subtract mi because userspace uses offset = N*PAGE_SIZE |
| 705 | * to use mem[N]. |
| 706 | */ |
| 707 | offset = (vmf->pgoff - mi) << PAGE_SHIFT; |
| 708 | |
| 709 | addr = (void *)(unsigned long)info->mem[mi].addr + offset; |
| 710 | if (info->mem[mi].memtype == UIO_MEM_LOGICAL) |
| 711 | page = virt_to_page(addr); |
| 712 | else |
| 713 | page = vmalloc_to_page(addr); |
| 714 | get_page(page); |
| 715 | vmf->page = page; |
| 716 | return 0; |
| 717 | } |
| 718 | |
| 719 | static const struct vm_operations_struct tcmu_vm_ops = { |
| 720 | .fault = tcmu_vma_fault, |
| 721 | }; |
| 722 | |
| 723 | static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma) |
| 724 | { |
| 725 | struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); |
| 726 | |
| 727 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
| 728 | vma->vm_ops = &tcmu_vm_ops; |
| 729 | |
| 730 | vma->vm_private_data = udev; |
| 731 | |
| 732 | /* Ensure the mmap is exactly the right size */ |
| 733 | if (vma_pages(vma) != (TCMU_RING_SIZE >> PAGE_SHIFT)) |
| 734 | return -EINVAL; |
| 735 | |
| 736 | return 0; |
| 737 | } |
| 738 | |
| 739 | static int tcmu_open(struct uio_info *info, struct inode *inode) |
| 740 | { |
| 741 | struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); |
| 742 | |
| 743 | /* O_EXCL not supported for char devs, so fake it? */ |
| 744 | if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags)) |
| 745 | return -EBUSY; |
| 746 | |
| 747 | pr_debug("open\n"); |
| 748 | |
| 749 | return 0; |
| 750 | } |
| 751 | |
| 752 | static int tcmu_release(struct uio_info *info, struct inode *inode) |
| 753 | { |
| 754 | struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info); |
| 755 | |
| 756 | clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags); |
| 757 | |
| 758 | pr_debug("close\n"); |
| 759 | |
| 760 | return 0; |
| 761 | } |
| 762 | |
| 763 | static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int minor) |
| 764 | { |
| 765 | struct sk_buff *skb; |
| 766 | void *msg_header; |
Nicholas Bellinger | 6e14eab | 2014-10-01 23:01:15 -0700 | [diff] [blame] | 767 | int ret = -ENOMEM; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 768 | |
| 769 | skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); |
| 770 | if (!skb) |
Nicholas Bellinger | 6e14eab | 2014-10-01 23:01:15 -0700 | [diff] [blame] | 771 | return ret; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 772 | |
| 773 | msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd); |
Nicholas Bellinger | 6e14eab | 2014-10-01 23:01:15 -0700 | [diff] [blame] | 774 | if (!msg_header) |
| 775 | goto free_skb; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 776 | |
| 777 | ret = nla_put_string(skb, TCMU_ATTR_DEVICE, name); |
Nicholas Bellinger | 6e14eab | 2014-10-01 23:01:15 -0700 | [diff] [blame] | 778 | if (ret < 0) |
| 779 | goto free_skb; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 780 | |
| 781 | ret = nla_put_u32(skb, TCMU_ATTR_MINOR, minor); |
Nicholas Bellinger | 6e14eab | 2014-10-01 23:01:15 -0700 | [diff] [blame] | 782 | if (ret < 0) |
| 783 | goto free_skb; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 784 | |
| 785 | ret = genlmsg_end(skb, msg_header); |
Nicholas Bellinger | 6e14eab | 2014-10-01 23:01:15 -0700 | [diff] [blame] | 786 | if (ret < 0) |
| 787 | goto free_skb; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 788 | |
| 789 | ret = genlmsg_multicast(&tcmu_genl_family, skb, 0, |
| 790 | TCMU_MCGRP_CONFIG, GFP_KERNEL); |
| 791 | |
| 792 | /* We don't care if no one is listening */ |
| 793 | if (ret == -ESRCH) |
| 794 | ret = 0; |
| 795 | |
| 796 | return ret; |
Nicholas Bellinger | 6e14eab | 2014-10-01 23:01:15 -0700 | [diff] [blame] | 797 | free_skb: |
| 798 | nlmsg_free(skb); |
| 799 | return ret; |
Andy Grover | 7c9e7a6 | 2014-10-01 16:07:05 -0700 | [diff] [blame] | 800 | } |
| 801 | |
| 802 | static int tcmu_configure_device(struct se_device *dev) |
| 803 | { |
| 804 | struct tcmu_dev *udev = TCMU_DEV(dev); |
| 805 | struct tcmu_hba *hba = udev->hba->hba_ptr; |
| 806 | struct uio_info *info; |
| 807 | struct tcmu_mailbox *mb; |
| 808 | size_t size; |
| 809 | size_t used; |
| 810 | int ret = 0; |
| 811 | char *str; |
| 812 | |
| 813 | info = &udev->uio_info; |
| 814 | |
| 815 | size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name, |
| 816 | udev->dev_config); |
| 817 | size += 1; /* for \0 */ |
| 818 | str = kmalloc(size, GFP_KERNEL); |
| 819 | if (!str) |
| 820 | return -ENOMEM; |
| 821 | |
| 822 | used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name); |
| 823 | |
| 824 | if (udev->dev_config[0]) |
| 825 | snprintf(str + used, size - used, "/%s", udev->dev_config); |
| 826 | |
| 827 | info->name = str; |
| 828 | |
| 829 | udev->mb_addr = vzalloc(TCMU_RING_SIZE); |
| 830 | if (!udev->mb_addr) { |
| 831 | ret = -ENOMEM; |
| 832 | goto err_vzalloc; |
| 833 | } |
| 834 | |
| 835 | /* mailbox fits in first part of CMDR space */ |
| 836 | udev->cmdr_size = CMDR_SIZE - CMDR_OFF; |
| 837 | udev->data_off = CMDR_SIZE; |
| 838 | udev->data_size = TCMU_RING_SIZE - CMDR_SIZE; |
| 839 | |
| 840 | mb = udev->mb_addr; |
| 841 | mb->version = 1; |
| 842 | mb->cmdr_off = CMDR_OFF; |
| 843 | mb->cmdr_size = udev->cmdr_size; |
| 844 | |
| 845 | WARN_ON(!PAGE_ALIGNED(udev->data_off)); |
| 846 | WARN_ON(udev->data_size % PAGE_SIZE); |
| 847 | |
| 848 | info->version = "1"; |
| 849 | |
| 850 | info->mem[0].name = "tcm-user command & data buffer"; |
| 851 | info->mem[0].addr = (phys_addr_t) udev->mb_addr; |
| 852 | info->mem[0].size = TCMU_RING_SIZE; |
| 853 | info->mem[0].memtype = UIO_MEM_VIRTUAL; |
| 854 | |
| 855 | info->irqcontrol = tcmu_irqcontrol; |
| 856 | info->irq = UIO_IRQ_CUSTOM; |
| 857 | |
| 858 | info->mmap = tcmu_mmap; |
| 859 | info->open = tcmu_open; |
| 860 | info->release = tcmu_release; |
| 861 | |
| 862 | ret = uio_register_device(tcmu_root_device, info); |
| 863 | if (ret) |
| 864 | goto err_register; |
| 865 | |
| 866 | /* Other attributes can be configured in userspace */ |
| 867 | dev->dev_attrib.hw_block_size = 512; |
| 868 | dev->dev_attrib.hw_max_sectors = 128; |
| 869 | dev->dev_attrib.hw_queue_depth = 128; |
| 870 | |
| 871 | ret = tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE, udev->uio_info.name, |
| 872 | udev->uio_info.uio_dev->minor); |
| 873 | if (ret) |
| 874 | goto err_netlink; |
| 875 | |
| 876 | return 0; |
| 877 | |
| 878 | err_netlink: |
| 879 | uio_unregister_device(&udev->uio_info); |
| 880 | err_register: |
| 881 | vfree(udev->mb_addr); |
| 882 | err_vzalloc: |
| 883 | kfree(info->name); |
| 884 | |
| 885 | return ret; |
| 886 | } |
| 887 | |
| 888 | static int tcmu_check_pending_cmd(int id, void *p, void *data) |
| 889 | { |
| 890 | struct tcmu_cmd *cmd = p; |
| 891 | |
| 892 | if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) |
| 893 | return 0; |
| 894 | return -EINVAL; |
| 895 | } |
| 896 | |
| 897 | static void tcmu_free_device(struct se_device *dev) |
| 898 | { |
| 899 | struct tcmu_dev *udev = TCMU_DEV(dev); |
| 900 | int i; |
| 901 | |
| 902 | del_timer_sync(&udev->timeout); |
| 903 | |
| 904 | vfree(udev->mb_addr); |
| 905 | |
| 906 | /* Upper layer should drain all requests before calling this */ |
| 907 | spin_lock_irq(&udev->commands_lock); |
| 908 | i = idr_for_each(&udev->commands, tcmu_check_pending_cmd, NULL); |
| 909 | idr_destroy(&udev->commands); |
| 910 | spin_unlock_irq(&udev->commands_lock); |
| 911 | WARN_ON(i); |
| 912 | |
| 913 | /* Device was configured */ |
| 914 | if (udev->uio_info.uio_dev) { |
| 915 | tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name, |
| 916 | udev->uio_info.uio_dev->minor); |
| 917 | |
| 918 | uio_unregister_device(&udev->uio_info); |
| 919 | kfree(udev->uio_info.name); |
| 920 | kfree(udev->name); |
| 921 | } |
| 922 | |
| 923 | kfree(udev); |
| 924 | } |
| 925 | |
| 926 | enum { |
| 927 | Opt_dev_config, Opt_dev_size, Opt_err, Opt_pass_level, |
| 928 | }; |
| 929 | |
| 930 | static match_table_t tokens = { |
| 931 | {Opt_dev_config, "dev_config=%s"}, |
| 932 | {Opt_dev_size, "dev_size=%u"}, |
| 933 | {Opt_pass_level, "pass_level=%u"}, |
| 934 | {Opt_err, NULL} |
| 935 | }; |
| 936 | |
| 937 | static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev, |
| 938 | const char *page, ssize_t count) |
| 939 | { |
| 940 | struct tcmu_dev *udev = TCMU_DEV(dev); |
| 941 | char *orig, *ptr, *opts, *arg_p; |
| 942 | substring_t args[MAX_OPT_ARGS]; |
| 943 | int ret = 0, token; |
| 944 | int arg; |
| 945 | |
| 946 | opts = kstrdup(page, GFP_KERNEL); |
| 947 | if (!opts) |
| 948 | return -ENOMEM; |
| 949 | |
| 950 | orig = opts; |
| 951 | |
| 952 | while ((ptr = strsep(&opts, ",\n")) != NULL) { |
| 953 | if (!*ptr) |
| 954 | continue; |
| 955 | |
| 956 | token = match_token(ptr, tokens, args); |
| 957 | switch (token) { |
| 958 | case Opt_dev_config: |
| 959 | if (match_strlcpy(udev->dev_config, &args[0], |
| 960 | TCMU_CONFIG_LEN) == 0) { |
| 961 | ret = -EINVAL; |
| 962 | break; |
| 963 | } |
| 964 | pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config); |
| 965 | break; |
| 966 | case Opt_dev_size: |
| 967 | arg_p = match_strdup(&args[0]); |
| 968 | if (!arg_p) { |
| 969 | ret = -ENOMEM; |
| 970 | break; |
| 971 | } |
| 972 | ret = kstrtoul(arg_p, 0, (unsigned long *) &udev->dev_size); |
| 973 | kfree(arg_p); |
| 974 | if (ret < 0) |
| 975 | pr_err("kstrtoul() failed for dev_size=\n"); |
| 976 | break; |
| 977 | case Opt_pass_level: |
| 978 | match_int(args, &arg); |
| 979 | if (arg >= TCMU_PASS_INVALID) { |
| 980 | pr_warn("TCMU: Invalid pass_level: %d\n", arg); |
| 981 | break; |
| 982 | } |
| 983 | |
| 984 | pr_debug("TCMU: Setting pass_level to %d\n", arg); |
| 985 | udev->pass_level = arg; |
| 986 | break; |
| 987 | default: |
| 988 | break; |
| 989 | } |
| 990 | } |
| 991 | |
| 992 | kfree(orig); |
| 993 | return (!ret) ? count : ret; |
| 994 | } |
| 995 | |
| 996 | static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b) |
| 997 | { |
| 998 | struct tcmu_dev *udev = TCMU_DEV(dev); |
| 999 | ssize_t bl = 0; |
| 1000 | |
| 1001 | bl = sprintf(b + bl, "Config: %s ", |
| 1002 | udev->dev_config[0] ? udev->dev_config : "NULL"); |
| 1003 | bl += sprintf(b + bl, "Size: %zu PassLevel: %u\n", |
| 1004 | udev->dev_size, udev->pass_level); |
| 1005 | |
| 1006 | return bl; |
| 1007 | } |
| 1008 | |
| 1009 | static sector_t tcmu_get_blocks(struct se_device *dev) |
| 1010 | { |
| 1011 | struct tcmu_dev *udev = TCMU_DEV(dev); |
| 1012 | |
| 1013 | return div_u64(udev->dev_size - dev->dev_attrib.block_size, |
| 1014 | dev->dev_attrib.block_size); |
| 1015 | } |
| 1016 | |
| 1017 | static sense_reason_t |
| 1018 | tcmu_execute_rw(struct se_cmd *se_cmd, struct scatterlist *sgl, u32 sgl_nents, |
| 1019 | enum dma_data_direction data_direction) |
| 1020 | { |
| 1021 | int ret; |
| 1022 | |
| 1023 | ret = tcmu_queue_cmd(se_cmd); |
| 1024 | |
| 1025 | if (ret != 0) |
| 1026 | return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; |
| 1027 | else |
| 1028 | return TCM_NO_SENSE; |
| 1029 | } |
| 1030 | |
| 1031 | static sense_reason_t |
| 1032 | tcmu_pass_op(struct se_cmd *se_cmd) |
| 1033 | { |
| 1034 | int ret = tcmu_queue_cmd(se_cmd); |
| 1035 | |
| 1036 | if (ret != 0) |
| 1037 | return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; |
| 1038 | else |
| 1039 | return TCM_NO_SENSE; |
| 1040 | } |
| 1041 | |
| 1042 | static struct sbc_ops tcmu_sbc_ops = { |
| 1043 | .execute_rw = tcmu_execute_rw, |
| 1044 | .execute_sync_cache = tcmu_pass_op, |
| 1045 | .execute_write_same = tcmu_pass_op, |
| 1046 | .execute_write_same_unmap = tcmu_pass_op, |
| 1047 | .execute_unmap = tcmu_pass_op, |
| 1048 | }; |
| 1049 | |
| 1050 | static sense_reason_t |
| 1051 | tcmu_parse_cdb(struct se_cmd *cmd) |
| 1052 | { |
| 1053 | unsigned char *cdb = cmd->t_task_cdb; |
| 1054 | struct tcmu_dev *udev = TCMU_DEV(cmd->se_dev); |
| 1055 | sense_reason_t ret; |
| 1056 | |
| 1057 | switch (udev->pass_level) { |
| 1058 | case TCMU_PASS_ALL: |
| 1059 | /* We're just like pscsi, then */ |
| 1060 | /* |
| 1061 | * For REPORT LUNS we always need to emulate the response, for everything |
| 1062 | * else, pass it up. |
| 1063 | */ |
| 1064 | switch (cdb[0]) { |
| 1065 | case REPORT_LUNS: |
| 1066 | cmd->execute_cmd = spc_emulate_report_luns; |
| 1067 | break; |
| 1068 | case READ_6: |
| 1069 | case READ_10: |
| 1070 | case READ_12: |
| 1071 | case READ_16: |
| 1072 | case WRITE_6: |
| 1073 | case WRITE_10: |
| 1074 | case WRITE_12: |
| 1075 | case WRITE_16: |
| 1076 | case WRITE_VERIFY: |
| 1077 | cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; |
| 1078 | /* FALLTHROUGH */ |
| 1079 | default: |
| 1080 | cmd->execute_cmd = tcmu_pass_op; |
| 1081 | } |
| 1082 | ret = TCM_NO_SENSE; |
| 1083 | break; |
| 1084 | case TCMU_PASS_IO: |
| 1085 | ret = sbc_parse_cdb(cmd, &tcmu_sbc_ops); |
| 1086 | break; |
| 1087 | default: |
| 1088 | pr_err("Unknown tcm-user pass level %d\n", udev->pass_level); |
| 1089 | ret = TCM_CHECK_CONDITION_ABORT_CMD; |
| 1090 | } |
| 1091 | |
| 1092 | return ret; |
| 1093 | } |
| 1094 | |
| 1095 | static struct se_subsystem_api tcmu_template = { |
| 1096 | .name = "user", |
| 1097 | .inquiry_prod = "USER", |
| 1098 | .inquiry_rev = TCMU_VERSION, |
| 1099 | .owner = THIS_MODULE, |
| 1100 | .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, |
| 1101 | .attach_hba = tcmu_attach_hba, |
| 1102 | .detach_hba = tcmu_detach_hba, |
| 1103 | .alloc_device = tcmu_alloc_device, |
| 1104 | .configure_device = tcmu_configure_device, |
| 1105 | .free_device = tcmu_free_device, |
| 1106 | .parse_cdb = tcmu_parse_cdb, |
| 1107 | .set_configfs_dev_params = tcmu_set_configfs_dev_params, |
| 1108 | .show_configfs_dev_params = tcmu_show_configfs_dev_params, |
| 1109 | .get_device_type = sbc_get_device_type, |
| 1110 | .get_blocks = tcmu_get_blocks, |
| 1111 | }; |
| 1112 | |
| 1113 | static int __init tcmu_module_init(void) |
| 1114 | { |
| 1115 | int ret; |
| 1116 | |
| 1117 | BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0); |
| 1118 | |
| 1119 | tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache", |
| 1120 | sizeof(struct tcmu_cmd), |
| 1121 | __alignof__(struct tcmu_cmd), |
| 1122 | 0, NULL); |
| 1123 | if (!tcmu_cmd_cache) |
| 1124 | return -ENOMEM; |
| 1125 | |
| 1126 | tcmu_root_device = root_device_register("tcm_user"); |
| 1127 | if (IS_ERR(tcmu_root_device)) { |
| 1128 | ret = PTR_ERR(tcmu_root_device); |
| 1129 | goto out_free_cache; |
| 1130 | } |
| 1131 | |
| 1132 | ret = genl_register_family(&tcmu_genl_family); |
| 1133 | if (ret < 0) { |
| 1134 | goto out_unreg_device; |
| 1135 | } |
| 1136 | |
| 1137 | ret = transport_subsystem_register(&tcmu_template); |
| 1138 | if (ret) |
| 1139 | goto out_unreg_genl; |
| 1140 | |
| 1141 | return 0; |
| 1142 | |
| 1143 | out_unreg_genl: |
| 1144 | genl_unregister_family(&tcmu_genl_family); |
| 1145 | out_unreg_device: |
| 1146 | root_device_unregister(tcmu_root_device); |
| 1147 | out_free_cache: |
| 1148 | kmem_cache_destroy(tcmu_cmd_cache); |
| 1149 | |
| 1150 | return ret; |
| 1151 | } |
| 1152 | |
| 1153 | static void __exit tcmu_module_exit(void) |
| 1154 | { |
| 1155 | transport_subsystem_release(&tcmu_template); |
| 1156 | genl_unregister_family(&tcmu_genl_family); |
| 1157 | root_device_unregister(tcmu_root_device); |
| 1158 | kmem_cache_destroy(tcmu_cmd_cache); |
| 1159 | } |
| 1160 | |
| 1161 | MODULE_DESCRIPTION("TCM USER subsystem plugin"); |
| 1162 | MODULE_AUTHOR("Shaohua Li <shli@kernel.org>"); |
| 1163 | MODULE_AUTHOR("Andy Grover <agrover@redhat.com>"); |
| 1164 | MODULE_LICENSE("GPL"); |
| 1165 | |
| 1166 | module_init(tcmu_module_init); |
| 1167 | module_exit(tcmu_module_exit); |