2 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
3 * Copyright (C) 2014 Red Hat, Inc.
4 * Copyright (C) 2015 Arrikto, Inc.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
20 #include <linux/spinlock.h>
21 #include <linux/module.h>
22 #include <linux/idr.h>
23 #include <linux/kernel.h>
24 #include <linux/timer.h>
25 #include <linux/parser.h>
26 #include <linux/vmalloc.h>
27 #include <linux/uio_driver.h>
28 #include <linux/stringify.h>
29 #include <net/genetlink.h>
30 #include <scsi/scsi_common.h>
31 #include <scsi/scsi_proto.h>
32 #include <target/target_core_base.h>
33 #include <target/target_core_fabric.h>
34 #include <target/target_core_backend.h>
36 #include <linux/target_core_user.h>
39 * Define a shared-memory interface for LIO to pass SCSI commands and
40 * data to userspace for processing. This is to allow backends that
41 * are too complex for in-kernel support to be possible.
43 * It uses the UIO framework to do a lot of the device-creation and
44 * introspection work for us.
46 * See the .h file for how the ring is laid out. Note that while the
47 * command ring is defined, the particulars of the data area are
48 * not. Offset values in the command entry point to other locations
49 * internal to the mmap()ed area. There is separate space outside the
50 * command ring for data buffers. This leaves maximum flexibility for
51 * moving buffer allocations, or even page flipping or other
52 * allocation techniques, without altering the command ring layout.
55 * The user process must be assumed to be malicious. There's no way to
56 * prevent it breaking the command ring protocol if it wants, but in
57 * order to prevent other issues we must only ever read *data* from
58 * the shared memory area, not offsets or sizes. This applies to
59 * command ring entries as well as the mailbox. Extra code needed for
60 * this may have a 'UAM' comment.
64 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
66 #define CMDR_SIZE (16 * 4096)
67 #define DATA_SIZE (257 * 4096)
69 #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
71 static struct device
*tcmu_root_device
;
77 #define TCMU_CONFIG_LEN 256
80 struct se_device se_dev
;
85 #define TCMU_DEV_BIT_OPEN 0
86 #define TCMU_DEV_BIT_BROKEN 1
89 struct uio_info uio_info
;
91 struct tcmu_mailbox
*mb_addr
;
94 u32 cmdr_last_cleaned
;
95 /* Offset of data ring from start of mb */
98 /* Ring head + tail values. */
99 /* Must add data_off and mb_addr to get the address */
103 wait_queue_head_t wait_cmdr
;
104 /* TODO should this be a mutex? */
105 spinlock_t cmdr_lock
;
108 spinlock_t commands_lock
;
110 struct timer_list timeout
;
112 char dev_config
[TCMU_CONFIG_LEN
];
115 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
117 #define CMDR_OFF sizeof(struct tcmu_mailbox)
120 struct se_cmd
*se_cmd
;
121 struct tcmu_dev
*tcmu_dev
;
125 /* Can't use se_cmd->data_length when cleaning up expired cmds, because if
126 cmd has been completed then accessing se_cmd is off limits */
129 unsigned long deadline
;
131 #define TCMU_CMD_BIT_EXPIRED 0
135 static struct kmem_cache
*tcmu_cmd_cache
;
137 /* multicast group */
138 enum tcmu_multicast_groups
{
142 static const struct genl_multicast_group tcmu_mcgrps
[] = {
143 [TCMU_MCGRP_CONFIG
] = { .name
= "config", },
146 /* Our generic netlink family */
147 static struct genl_family tcmu_genl_family
= {
148 .id
= GENL_ID_GENERATE
,
152 .maxattr
= TCMU_ATTR_MAX
,
153 .mcgrps
= tcmu_mcgrps
,
154 .n_mcgrps
= ARRAY_SIZE(tcmu_mcgrps
),
158 static struct tcmu_cmd
*tcmu_alloc_cmd(struct se_cmd
*se_cmd
)
160 struct se_device
*se_dev
= se_cmd
->se_dev
;
161 struct tcmu_dev
*udev
= TCMU_DEV(se_dev
);
162 struct tcmu_cmd
*tcmu_cmd
;
165 tcmu_cmd
= kmem_cache_zalloc(tcmu_cmd_cache
, GFP_KERNEL
);
169 tcmu_cmd
->se_cmd
= se_cmd
;
170 tcmu_cmd
->tcmu_dev
= udev
;
171 tcmu_cmd
->data_length
= se_cmd
->data_length
;
173 if (se_cmd
->se_cmd_flags
& SCF_BIDI
) {
174 BUG_ON(!(se_cmd
->t_bidi_data_sg
&& se_cmd
->t_bidi_data_nents
));
175 tcmu_cmd
->data_length
+= se_cmd
->t_bidi_data_sg
->length
;
178 tcmu_cmd
->deadline
= jiffies
+ msecs_to_jiffies(TCMU_TIME_OUT
);
180 idr_preload(GFP_KERNEL
);
181 spin_lock_irq(&udev
->commands_lock
);
182 cmd_id
= idr_alloc(&udev
->commands
, tcmu_cmd
, 0,
183 USHRT_MAX
, GFP_NOWAIT
);
184 spin_unlock_irq(&udev
->commands_lock
);
188 kmem_cache_free(tcmu_cmd_cache
, tcmu_cmd
);
191 tcmu_cmd
->cmd_id
= cmd_id
;
196 static inline void tcmu_flush_dcache_range(void *vaddr
, size_t size
)
198 unsigned long offset
= offset_in_page(vaddr
);
200 size
= round_up(size
+offset
, PAGE_SIZE
);
204 flush_dcache_page(virt_to_page(vaddr
));
210 * Some ring helper functions. We don't assume size is a power of 2 so
211 * we can't use circ_buf.h.
213 static inline size_t spc_used(size_t head
, size_t tail
, size_t size
)
215 int diff
= head
- tail
;
223 static inline size_t spc_free(size_t head
, size_t tail
, size_t size
)
225 /* Keep 1 byte unused or we can't tell full from empty */
226 return (size
- spc_used(head
, tail
, size
) - 1);
229 static inline size_t head_to_end(size_t head
, size_t size
)
234 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
236 static void alloc_and_scatter_data_area(struct tcmu_dev
*udev
,
237 struct scatterlist
*data_sg
, unsigned int data_nents
,
238 struct iovec
**iov
, int *iov_cnt
, bool copy_data
)
243 struct scatterlist
*sg
;
245 for_each_sg(data_sg
, sg
, data_nents
, i
) {
246 copy_bytes
= min_t(size_t, sg
->length
,
247 head_to_end(udev
->data_head
, udev
->data_size
));
248 from
= kmap_atomic(sg_page(sg
)) + sg
->offset
;
249 to
= (void *) udev
->mb_addr
+ udev
->data_off
+ udev
->data_head
;
252 memcpy(to
, from
, copy_bytes
);
253 tcmu_flush_dcache_range(to
, copy_bytes
);
256 /* Even iov_base is relative to mb_addr */
257 (*iov
)->iov_len
= copy_bytes
;
258 (*iov
)->iov_base
= (void __user
*) udev
->data_off
+
263 UPDATE_HEAD(udev
->data_head
, copy_bytes
, udev
->data_size
);
265 /* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */
266 if (sg
->length
!= copy_bytes
) {
267 void *from_skip
= from
+ copy_bytes
;
269 copy_bytes
= sg
->length
- copy_bytes
;
271 (*iov
)->iov_len
= copy_bytes
;
272 (*iov
)->iov_base
= (void __user
*) udev
->data_off
+
276 to
= (void *) udev
->mb_addr
+
277 udev
->data_off
+ udev
->data_head
;
278 memcpy(to
, from_skip
, copy_bytes
);
279 tcmu_flush_dcache_range(to
, copy_bytes
);
285 UPDATE_HEAD(udev
->data_head
,
286 copy_bytes
, udev
->data_size
);
289 kunmap_atomic(from
- sg
->offset
);
293 static void gather_and_free_data_area(struct tcmu_dev
*udev
,
294 struct scatterlist
*data_sg
, unsigned int data_nents
)
299 struct scatterlist
*sg
;
301 /* It'd be easier to look at entry's iovec again, but UAM */
302 for_each_sg(data_sg
, sg
, data_nents
, i
) {
303 copy_bytes
= min_t(size_t, sg
->length
,
304 head_to_end(udev
->data_tail
, udev
->data_size
));
306 to
= kmap_atomic(sg_page(sg
)) + sg
->offset
;
307 WARN_ON(sg
->length
+ sg
->offset
> PAGE_SIZE
);
308 from
= (void *) udev
->mb_addr
+
309 udev
->data_off
+ udev
->data_tail
;
310 tcmu_flush_dcache_range(from
, copy_bytes
);
311 memcpy(to
, from
, copy_bytes
);
313 UPDATE_HEAD(udev
->data_tail
, copy_bytes
, udev
->data_size
);
315 /* Uh oh, wrapped the data buffer for this sg's data */
316 if (sg
->length
!= copy_bytes
) {
317 void *to_skip
= to
+ copy_bytes
;
319 from
= (void *) udev
->mb_addr
+
320 udev
->data_off
+ udev
->data_tail
;
321 WARN_ON(udev
->data_tail
);
322 copy_bytes
= sg
->length
- copy_bytes
;
323 tcmu_flush_dcache_range(from
, copy_bytes
);
324 memcpy(to_skip
, from
, copy_bytes
);
326 UPDATE_HEAD(udev
->data_tail
,
327 copy_bytes
, udev
->data_size
);
329 kunmap_atomic(to
- sg
->offset
);
334 * We can't queue a command until we have space available on the cmd ring *and*
335 * space available on the data ring.
337 * Called with ring lock held.
339 static bool is_ring_space_avail(struct tcmu_dev
*udev
, size_t cmd_size
, size_t data_needed
)
341 struct tcmu_mailbox
*mb
= udev
->mb_addr
;
346 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
348 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
351 * If cmd end-of-ring space is too small then we need space for a NOP plus
352 * original cmd - cmds are internally contiguous.
354 if (head_to_end(cmd_head
, udev
->cmdr_size
) >= cmd_size
)
355 cmd_needed
= cmd_size
;
357 cmd_needed
= cmd_size
+ head_to_end(cmd_head
, udev
->cmdr_size
);
359 space
= spc_free(cmd_head
, udev
->cmdr_last_cleaned
, udev
->cmdr_size
);
360 if (space
< cmd_needed
) {
361 pr_debug("no cmd space: %u %u %u\n", cmd_head
,
362 udev
->cmdr_last_cleaned
, udev
->cmdr_size
);
366 space
= spc_free(udev
->data_head
, udev
->data_tail
, udev
->data_size
);
367 if (space
< data_needed
) {
368 pr_debug("no data space: %zu %zu %zu\n", udev
->data_head
,
369 udev
->data_tail
, udev
->data_size
);
376 static int tcmu_queue_cmd_ring(struct tcmu_cmd
*tcmu_cmd
)
378 struct tcmu_dev
*udev
= tcmu_cmd
->tcmu_dev
;
379 struct se_cmd
*se_cmd
= tcmu_cmd
->se_cmd
;
380 size_t base_command_size
, command_size
;
381 struct tcmu_mailbox
*mb
;
382 struct tcmu_cmd_entry
*entry
;
387 bool copy_to_data_area
;
389 if (test_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
))
393 * Must be a certain minimum size for response sense info, but
394 * also may be larger if the iov array is large.
396 * iovs = sgl_nents+1, for end-of-ring case, plus another 1
397 * b/c size == offsetof one-past-element.
399 base_command_size
= max(offsetof(struct tcmu_cmd_entry
,
400 req
.iov
[se_cmd
->t_bidi_data_nents
+
401 se_cmd
->t_data_nents
+ 2]),
402 sizeof(struct tcmu_cmd_entry
));
403 command_size
= base_command_size
404 + round_up(scsi_command_size(se_cmd
->t_task_cdb
), TCMU_OP_ALIGN_SIZE
);
406 WARN_ON(command_size
& (TCMU_OP_ALIGN_SIZE
-1));
408 spin_lock_irq(&udev
->cmdr_lock
);
411 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
412 if ((command_size
> (udev
->cmdr_size
/ 2))
413 || tcmu_cmd
->data_length
> (udev
->data_size
- 1))
414 pr_warn("TCMU: Request of size %zu/%zu may be too big for %u/%zu "
415 "cmd/data ring buffers\n", command_size
, tcmu_cmd
->data_length
,
416 udev
->cmdr_size
, udev
->data_size
);
418 while (!is_ring_space_avail(udev
, command_size
, tcmu_cmd
->data_length
)) {
422 prepare_to_wait(&udev
->wait_cmdr
, &__wait
, TASK_INTERRUPTIBLE
);
424 pr_debug("sleeping for ring space\n");
425 spin_unlock_irq(&udev
->cmdr_lock
);
426 ret
= schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT
));
427 finish_wait(&udev
->wait_cmdr
, &__wait
);
429 pr_warn("tcmu: command timed out\n");
433 spin_lock_irq(&udev
->cmdr_lock
);
435 /* We dropped cmdr_lock, cmd_head is stale */
436 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
439 /* Insert a PAD if end-of-ring space is too small */
440 if (head_to_end(cmd_head
, udev
->cmdr_size
) < command_size
) {
441 size_t pad_size
= head_to_end(cmd_head
, udev
->cmdr_size
);
443 entry
= (void *) mb
+ CMDR_OFF
+ cmd_head
;
444 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
445 tcmu_hdr_set_op(&entry
->hdr
.len_op
, TCMU_OP_PAD
);
446 tcmu_hdr_set_len(&entry
->hdr
.len_op
, pad_size
);
447 entry
->hdr
.cmd_id
= 0; /* not used for PAD */
448 entry
->hdr
.kflags
= 0;
449 entry
->hdr
.uflags
= 0;
451 UPDATE_HEAD(mb
->cmd_head
, pad_size
, udev
->cmdr_size
);
453 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
454 WARN_ON(cmd_head
!= 0);
457 entry
= (void *) mb
+ CMDR_OFF
+ cmd_head
;
458 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
459 tcmu_hdr_set_op(&entry
->hdr
.len_op
, TCMU_OP_CMD
);
460 tcmu_hdr_set_len(&entry
->hdr
.len_op
, command_size
);
461 entry
->hdr
.cmd_id
= tcmu_cmd
->cmd_id
;
462 entry
->hdr
.kflags
= 0;
463 entry
->hdr
.uflags
= 0;
466 * Fix up iovecs, and handle if allocation in data ring wrapped.
468 iov
= &entry
->req
.iov
[0];
470 copy_to_data_area
= (se_cmd
->data_direction
== DMA_TO_DEVICE
471 || se_cmd
->se_cmd_flags
& SCF_BIDI
);
472 alloc_and_scatter_data_area(udev
, se_cmd
->t_data_sg
,
473 se_cmd
->t_data_nents
, &iov
, &iov_cnt
, copy_to_data_area
);
474 entry
->req
.iov_cnt
= iov_cnt
;
475 entry
->req
.iov_dif_cnt
= 0;
477 /* Handle BIDI commands */
479 alloc_and_scatter_data_area(udev
, se_cmd
->t_bidi_data_sg
,
480 se_cmd
->t_bidi_data_nents
, &iov
, &iov_cnt
, false);
481 entry
->req
.iov_bidi_cnt
= iov_cnt
;
483 /* All offsets relative to mb_addr, not start of entry! */
484 cdb_off
= CMDR_OFF
+ cmd_head
+ base_command_size
;
485 memcpy((void *) mb
+ cdb_off
, se_cmd
->t_task_cdb
, scsi_command_size(se_cmd
->t_task_cdb
));
486 entry
->req
.cdb_off
= cdb_off
;
487 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
489 UPDATE_HEAD(mb
->cmd_head
, command_size
, udev
->cmdr_size
);
490 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
492 spin_unlock_irq(&udev
->cmdr_lock
);
494 /* TODO: only if FLUSH and FUA? */
495 uio_event_notify(&udev
->uio_info
);
497 mod_timer(&udev
->timeout
,
498 round_jiffies_up(jiffies
+ msecs_to_jiffies(TCMU_TIME_OUT
)));
503 static int tcmu_queue_cmd(struct se_cmd
*se_cmd
)
505 struct se_device
*se_dev
= se_cmd
->se_dev
;
506 struct tcmu_dev
*udev
= TCMU_DEV(se_dev
);
507 struct tcmu_cmd
*tcmu_cmd
;
510 tcmu_cmd
= tcmu_alloc_cmd(se_cmd
);
514 ret
= tcmu_queue_cmd_ring(tcmu_cmd
);
516 pr_err("TCMU: Could not queue command\n");
517 spin_lock_irq(&udev
->commands_lock
);
518 idr_remove(&udev
->commands
, tcmu_cmd
->cmd_id
);
519 spin_unlock_irq(&udev
->commands_lock
);
521 kmem_cache_free(tcmu_cmd_cache
, tcmu_cmd
);
527 static void tcmu_handle_completion(struct tcmu_cmd
*cmd
, struct tcmu_cmd_entry
*entry
)
529 struct se_cmd
*se_cmd
= cmd
->se_cmd
;
530 struct tcmu_dev
*udev
= cmd
->tcmu_dev
;
532 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
)) {
533 /* cmd has been completed already from timeout, just reclaim data
535 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
539 if (entry
->hdr
.uflags
& TCMU_UFLAG_UNKNOWN_OP
) {
540 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
541 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
543 entry
->rsp
.scsi_status
= SAM_STAT_CHECK_CONDITION
;
544 } else if (entry
->rsp
.scsi_status
== SAM_STAT_CHECK_CONDITION
) {
545 memcpy(se_cmd
->sense_buffer
, entry
->rsp
.sense_buffer
,
546 se_cmd
->scsi_sense_length
);
548 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
549 } else if (se_cmd
->se_cmd_flags
& SCF_BIDI
) {
550 /* Discard data_out buffer */
551 UPDATE_HEAD(udev
->data_tail
,
552 (size_t)se_cmd
->t_data_sg
->length
, udev
->data_size
);
554 /* Get Data-In buffer */
555 gather_and_free_data_area(udev
,
556 se_cmd
->t_bidi_data_sg
, se_cmd
->t_bidi_data_nents
);
557 } else if (se_cmd
->data_direction
== DMA_FROM_DEVICE
) {
558 gather_and_free_data_area(udev
,
559 se_cmd
->t_data_sg
, se_cmd
->t_data_nents
);
560 } else if (se_cmd
->data_direction
== DMA_TO_DEVICE
) {
561 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
562 } else if (se_cmd
->data_direction
!= DMA_NONE
) {
563 pr_warn("TCMU: data direction was %d!\n",
564 se_cmd
->data_direction
);
567 target_complete_cmd(cmd
->se_cmd
, entry
->rsp
.scsi_status
);
570 kmem_cache_free(tcmu_cmd_cache
, cmd
);
573 static unsigned int tcmu_handle_completions(struct tcmu_dev
*udev
)
575 struct tcmu_mailbox
*mb
;
579 if (test_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
)) {
580 pr_err("ring broken, not handling completions\n");
584 spin_lock_irqsave(&udev
->cmdr_lock
, flags
);
587 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
589 while (udev
->cmdr_last_cleaned
!= ACCESS_ONCE(mb
->cmd_tail
)) {
591 struct tcmu_cmd_entry
*entry
= (void *) mb
+ CMDR_OFF
+ udev
->cmdr_last_cleaned
;
592 struct tcmu_cmd
*cmd
;
594 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
596 if (tcmu_hdr_get_op(entry
->hdr
.len_op
) == TCMU_OP_PAD
) {
597 UPDATE_HEAD(udev
->cmdr_last_cleaned
,
598 tcmu_hdr_get_len(entry
->hdr
.len_op
),
602 WARN_ON(tcmu_hdr_get_op(entry
->hdr
.len_op
) != TCMU_OP_CMD
);
604 spin_lock(&udev
->commands_lock
);
605 cmd
= idr_find(&udev
->commands
, entry
->hdr
.cmd_id
);
607 idr_remove(&udev
->commands
, cmd
->cmd_id
);
608 spin_unlock(&udev
->commands_lock
);
611 pr_err("cmd_id not found, ring is broken\n");
612 set_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
);
616 tcmu_handle_completion(cmd
, entry
);
618 UPDATE_HEAD(udev
->cmdr_last_cleaned
,
619 tcmu_hdr_get_len(entry
->hdr
.len_op
),
625 if (mb
->cmd_tail
== mb
->cmd_head
)
626 del_timer(&udev
->timeout
); /* no more pending cmds */
628 spin_unlock_irqrestore(&udev
->cmdr_lock
, flags
);
630 wake_up(&udev
->wait_cmdr
);
635 static int tcmu_check_expired_cmd(int id
, void *p
, void *data
)
637 struct tcmu_cmd
*cmd
= p
;
639 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
))
642 if (!time_after(jiffies
, cmd
->deadline
))
645 set_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
);
646 target_complete_cmd(cmd
->se_cmd
, SAM_STAT_CHECK_CONDITION
);
649 kmem_cache_free(tcmu_cmd_cache
, cmd
);
654 static void tcmu_device_timedout(unsigned long data
)
656 struct tcmu_dev
*udev
= (struct tcmu_dev
*)data
;
660 handled
= tcmu_handle_completions(udev
);
662 pr_warn("%d completions handled from timeout\n", handled
);
664 spin_lock_irqsave(&udev
->commands_lock
, flags
);
665 idr_for_each(&udev
->commands
, tcmu_check_expired_cmd
, NULL
);
666 spin_unlock_irqrestore(&udev
->commands_lock
, flags
);
669 * We don't need to wakeup threads on wait_cmdr since they have their
674 static int tcmu_attach_hba(struct se_hba
*hba
, u32 host_id
)
676 struct tcmu_hba
*tcmu_hba
;
678 tcmu_hba
= kzalloc(sizeof(struct tcmu_hba
), GFP_KERNEL
);
682 tcmu_hba
->host_id
= host_id
;
683 hba
->hba_ptr
= tcmu_hba
;
688 static void tcmu_detach_hba(struct se_hba
*hba
)
694 static struct se_device
*tcmu_alloc_device(struct se_hba
*hba
, const char *name
)
696 struct tcmu_dev
*udev
;
698 udev
= kzalloc(sizeof(struct tcmu_dev
), GFP_KERNEL
);
702 udev
->name
= kstrdup(name
, GFP_KERNEL
);
710 init_waitqueue_head(&udev
->wait_cmdr
);
711 spin_lock_init(&udev
->cmdr_lock
);
713 idr_init(&udev
->commands
);
714 spin_lock_init(&udev
->commands_lock
);
716 setup_timer(&udev
->timeout
, tcmu_device_timedout
,
717 (unsigned long)udev
);
719 return &udev
->se_dev
;
722 static int tcmu_irqcontrol(struct uio_info
*info
, s32 irq_on
)
724 struct tcmu_dev
*tcmu_dev
= container_of(info
, struct tcmu_dev
, uio_info
);
726 tcmu_handle_completions(tcmu_dev
);
732 * mmap code from uio.c. Copied here because we want to hook mmap()
733 * and this stuff must come along.
735 static int tcmu_find_mem_index(struct vm_area_struct
*vma
)
737 struct tcmu_dev
*udev
= vma
->vm_private_data
;
738 struct uio_info
*info
= &udev
->uio_info
;
740 if (vma
->vm_pgoff
< MAX_UIO_MAPS
) {
741 if (info
->mem
[vma
->vm_pgoff
].size
== 0)
743 return (int)vma
->vm_pgoff
;
748 static int tcmu_vma_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
750 struct tcmu_dev
*udev
= vma
->vm_private_data
;
751 struct uio_info
*info
= &udev
->uio_info
;
753 unsigned long offset
;
756 int mi
= tcmu_find_mem_index(vma
);
758 return VM_FAULT_SIGBUS
;
761 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
764 offset
= (vmf
->pgoff
- mi
) << PAGE_SHIFT
;
766 addr
= (void *)(unsigned long)info
->mem
[mi
].addr
+ offset
;
767 if (info
->mem
[mi
].memtype
== UIO_MEM_LOGICAL
)
768 page
= virt_to_page(addr
);
770 page
= vmalloc_to_page(addr
);
776 static const struct vm_operations_struct tcmu_vm_ops
= {
777 .fault
= tcmu_vma_fault
,
780 static int tcmu_mmap(struct uio_info
*info
, struct vm_area_struct
*vma
)
782 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
784 vma
->vm_flags
|= VM_DONTEXPAND
| VM_DONTDUMP
;
785 vma
->vm_ops
= &tcmu_vm_ops
;
787 vma
->vm_private_data
= udev
;
789 /* Ensure the mmap is exactly the right size */
790 if (vma_pages(vma
) != (TCMU_RING_SIZE
>> PAGE_SHIFT
))
796 static int tcmu_open(struct uio_info
*info
, struct inode
*inode
)
798 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
800 /* O_EXCL not supported for char devs, so fake it? */
801 if (test_and_set_bit(TCMU_DEV_BIT_OPEN
, &udev
->flags
))
809 static int tcmu_release(struct uio_info
*info
, struct inode
*inode
)
811 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
813 clear_bit(TCMU_DEV_BIT_OPEN
, &udev
->flags
);
820 static int tcmu_netlink_event(enum tcmu_genl_cmd cmd
, const char *name
, int minor
)
826 skb
= genlmsg_new(NLMSG_GOODSIZE
, GFP_KERNEL
);
830 msg_header
= genlmsg_put(skb
, 0, 0, &tcmu_genl_family
, 0, cmd
);
834 ret
= nla_put_string(skb
, TCMU_ATTR_DEVICE
, name
);
838 ret
= nla_put_u32(skb
, TCMU_ATTR_MINOR
, minor
);
842 genlmsg_end(skb
, msg_header
);
844 ret
= genlmsg_multicast_allns(&tcmu_genl_family
, skb
, 0,
845 TCMU_MCGRP_CONFIG
, GFP_KERNEL
);
847 /* We don't care if no one is listening */
857 static int tcmu_configure_device(struct se_device
*dev
)
859 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
860 struct tcmu_hba
*hba
= udev
->hba
->hba_ptr
;
861 struct uio_info
*info
;
862 struct tcmu_mailbox
*mb
;
868 info
= &udev
->uio_info
;
870 size
= snprintf(NULL
, 0, "tcm-user/%u/%s/%s", hba
->host_id
, udev
->name
,
872 size
+= 1; /* for \0 */
873 str
= kmalloc(size
, GFP_KERNEL
);
877 used
= snprintf(str
, size
, "tcm-user/%u/%s", hba
->host_id
, udev
->name
);
879 if (udev
->dev_config
[0])
880 snprintf(str
+ used
, size
- used
, "/%s", udev
->dev_config
);
884 udev
->mb_addr
= vzalloc(TCMU_RING_SIZE
);
885 if (!udev
->mb_addr
) {
890 /* mailbox fits in first part of CMDR space */
891 udev
->cmdr_size
= CMDR_SIZE
- CMDR_OFF
;
892 udev
->data_off
= CMDR_SIZE
;
893 udev
->data_size
= TCMU_RING_SIZE
- CMDR_SIZE
;
896 mb
->version
= TCMU_MAILBOX_VERSION
;
897 mb
->cmdr_off
= CMDR_OFF
;
898 mb
->cmdr_size
= udev
->cmdr_size
;
900 WARN_ON(!PAGE_ALIGNED(udev
->data_off
));
901 WARN_ON(udev
->data_size
% PAGE_SIZE
);
903 info
->version
= __stringify(TCMU_MAILBOX_VERSION
);
905 info
->mem
[0].name
= "tcm-user command & data buffer";
906 info
->mem
[0].addr
= (phys_addr_t
)(uintptr_t)udev
->mb_addr
;
907 info
->mem
[0].size
= TCMU_RING_SIZE
;
908 info
->mem
[0].memtype
= UIO_MEM_VIRTUAL
;
910 info
->irqcontrol
= tcmu_irqcontrol
;
911 info
->irq
= UIO_IRQ_CUSTOM
;
913 info
->mmap
= tcmu_mmap
;
914 info
->open
= tcmu_open
;
915 info
->release
= tcmu_release
;
917 ret
= uio_register_device(tcmu_root_device
, info
);
921 /* User can set hw_block_size before enable the device */
922 if (dev
->dev_attrib
.hw_block_size
== 0)
923 dev
->dev_attrib
.hw_block_size
= 512;
924 /* Other attributes can be configured in userspace */
925 dev
->dev_attrib
.hw_max_sectors
= 128;
926 dev
->dev_attrib
.hw_queue_depth
= 128;
928 ret
= tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE
, udev
->uio_info
.name
,
929 udev
->uio_info
.uio_dev
->minor
);
936 uio_unregister_device(&udev
->uio_info
);
938 vfree(udev
->mb_addr
);
945 static int tcmu_check_pending_cmd(int id
, void *p
, void *data
)
947 struct tcmu_cmd
*cmd
= p
;
949 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
))
954 static void tcmu_dev_call_rcu(struct rcu_head
*p
)
956 struct se_device
*dev
= container_of(p
, struct se_device
, rcu_head
);
957 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
962 static void tcmu_free_device(struct se_device
*dev
)
964 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
967 del_timer_sync(&udev
->timeout
);
969 vfree(udev
->mb_addr
);
971 /* Upper layer should drain all requests before calling this */
972 spin_lock_irq(&udev
->commands_lock
);
973 i
= idr_for_each(&udev
->commands
, tcmu_check_pending_cmd
, NULL
);
974 idr_destroy(&udev
->commands
);
975 spin_unlock_irq(&udev
->commands_lock
);
978 /* Device was configured */
979 if (udev
->uio_info
.uio_dev
) {
980 tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE
, udev
->uio_info
.name
,
981 udev
->uio_info
.uio_dev
->minor
);
983 uio_unregister_device(&udev
->uio_info
);
984 kfree(udev
->uio_info
.name
);
987 call_rcu(&dev
->rcu_head
, tcmu_dev_call_rcu
);
991 Opt_dev_config
, Opt_dev_size
, Opt_hw_block_size
, Opt_err
,
994 static match_table_t tokens
= {
995 {Opt_dev_config
, "dev_config=%s"},
996 {Opt_dev_size
, "dev_size=%u"},
997 {Opt_hw_block_size
, "hw_block_size=%u"},
1001 static ssize_t
tcmu_set_configfs_dev_params(struct se_device
*dev
,
1002 const char *page
, ssize_t count
)
1004 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1005 char *orig
, *ptr
, *opts
, *arg_p
;
1006 substring_t args
[MAX_OPT_ARGS
];
1008 unsigned long tmp_ul
;
1010 opts
= kstrdup(page
, GFP_KERNEL
);
1016 while ((ptr
= strsep(&opts
, ",\n")) != NULL
) {
1020 token
= match_token(ptr
, tokens
, args
);
1022 case Opt_dev_config
:
1023 if (match_strlcpy(udev
->dev_config
, &args
[0],
1024 TCMU_CONFIG_LEN
) == 0) {
1028 pr_debug("TCMU: Referencing Path: %s\n", udev
->dev_config
);
1031 arg_p
= match_strdup(&args
[0]);
1036 ret
= kstrtoul(arg_p
, 0, (unsigned long *) &udev
->dev_size
);
1039 pr_err("kstrtoul() failed for dev_size=\n");
1041 case Opt_hw_block_size
:
1042 arg_p
= match_strdup(&args
[0]);
1047 ret
= kstrtoul(arg_p
, 0, &tmp_ul
);
1050 pr_err("kstrtoul() failed for hw_block_size=\n");
1054 pr_err("hw_block_size must be nonzero\n");
1057 dev
->dev_attrib
.hw_block_size
= tmp_ul
;
1065 return (!ret
) ? count
: ret
;
1068 static ssize_t
tcmu_show_configfs_dev_params(struct se_device
*dev
, char *b
)
1070 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1073 bl
= sprintf(b
+ bl
, "Config: %s ",
1074 udev
->dev_config
[0] ? udev
->dev_config
: "NULL");
1075 bl
+= sprintf(b
+ bl
, "Size: %zu\n", udev
->dev_size
);
1080 static sector_t
tcmu_get_blocks(struct se_device
*dev
)
1082 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1084 return div_u64(udev
->dev_size
- dev
->dev_attrib
.block_size
,
1085 dev
->dev_attrib
.block_size
);
1088 static sense_reason_t
1089 tcmu_pass_op(struct se_cmd
*se_cmd
)
1091 int ret
= tcmu_queue_cmd(se_cmd
);
1094 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
1096 return TCM_NO_SENSE
;
1099 static sense_reason_t
1100 tcmu_parse_cdb(struct se_cmd
*cmd
)
1102 return passthrough_parse_cdb(cmd
, tcmu_pass_op
);
1105 static const struct target_backend_ops tcmu_ops
= {
1107 .owner
= THIS_MODULE
,
1108 .transport_flags
= TRANSPORT_FLAG_PASSTHROUGH
,
1109 .attach_hba
= tcmu_attach_hba
,
1110 .detach_hba
= tcmu_detach_hba
,
1111 .alloc_device
= tcmu_alloc_device
,
1112 .configure_device
= tcmu_configure_device
,
1113 .free_device
= tcmu_free_device
,
1114 .parse_cdb
= tcmu_parse_cdb
,
1115 .set_configfs_dev_params
= tcmu_set_configfs_dev_params
,
1116 .show_configfs_dev_params
= tcmu_show_configfs_dev_params
,
1117 .get_device_type
= sbc_get_device_type
,
1118 .get_blocks
= tcmu_get_blocks
,
1119 .tb_dev_attrib_attrs
= passthrough_attrib_attrs
,
1122 static int __init
tcmu_module_init(void)
1126 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry
) % TCMU_OP_ALIGN_SIZE
) != 0);
1128 tcmu_cmd_cache
= kmem_cache_create("tcmu_cmd_cache",
1129 sizeof(struct tcmu_cmd
),
1130 __alignof__(struct tcmu_cmd
),
1132 if (!tcmu_cmd_cache
)
1135 tcmu_root_device
= root_device_register("tcm_user");
1136 if (IS_ERR(tcmu_root_device
)) {
1137 ret
= PTR_ERR(tcmu_root_device
);
1138 goto out_free_cache
;
1141 ret
= genl_register_family(&tcmu_genl_family
);
1143 goto out_unreg_device
;
1146 ret
= transport_backend_register(&tcmu_ops
);
1148 goto out_unreg_genl
;
1153 genl_unregister_family(&tcmu_genl_family
);
1155 root_device_unregister(tcmu_root_device
);
1157 kmem_cache_destroy(tcmu_cmd_cache
);
1162 static void __exit
tcmu_module_exit(void)
1164 target_backend_unregister(&tcmu_ops
);
1165 genl_unregister_family(&tcmu_genl_family
);
1166 root_device_unregister(tcmu_root_device
);
1167 kmem_cache_destroy(tcmu_cmd_cache
);
1170 MODULE_DESCRIPTION("TCM USER subsystem plugin");
1171 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
1172 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
1173 MODULE_LICENSE("GPL");
1175 module_init(tcmu_module_init
);
1176 module_exit(tcmu_module_exit
);