2 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
3 * Copyright (C) 2014 Red Hat, Inc.
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.
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
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.
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 <target/target_core_backend_configfs.h>
33 #include <linux/target_core_user.h>
36 * Define a shared-memory interface for LIO to pass SCSI commands and
37 * data to userspace for processing. This is to allow backends that
38 * are too complex for in-kernel support to be possible.
40 * It uses the UIO framework to do a lot of the device-creation and
41 * introspection work for us.
43 * See the .h file for how the ring is laid out. Note that while the
44 * command ring is defined, the particulars of the data area are
45 * not. Offset values in the command entry point to other locations
46 * internal to the mmap()ed area. There is separate space outside the
47 * command ring for data buffers. This leaves maximum flexibility for
48 * moving buffer allocations, or even page flipping or other
49 * allocation techniques, without altering the command ring layout.
52 * The user process must be assumed to be malicious. There's no way to
53 * prevent it breaking the command ring protocol if it wants, but in
54 * order to prevent other issues we must only ever read *data* from
55 * the shared memory area, not offsets or sizes. This applies to
56 * command ring entries as well as the mailbox. Extra code needed for
57 * this may have a 'UAM' comment.
61 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
63 #define CMDR_SIZE (16 * 4096)
64 #define DATA_SIZE (257 * 4096)
66 #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
68 static struct device
*tcmu_root_device
;
74 #define TCMU_CONFIG_LEN 256
77 struct se_device se_dev
;
82 #define TCMU_DEV_BIT_OPEN 0
83 #define TCMU_DEV_BIT_BROKEN 1
86 struct uio_info uio_info
;
88 struct tcmu_mailbox
*mb_addr
;
91 u32 cmdr_last_cleaned
;
92 /* Offset of data ring from start of mb */
95 /* Ring head + tail values. */
96 /* Must add data_off and mb_addr to get the address */
100 wait_queue_head_t wait_cmdr
;
101 /* TODO should this be a mutex? */
102 spinlock_t cmdr_lock
;
105 spinlock_t commands_lock
;
107 struct timer_list timeout
;
109 char dev_config
[TCMU_CONFIG_LEN
];
112 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
114 #define CMDR_OFF sizeof(struct tcmu_mailbox)
117 struct se_cmd
*se_cmd
;
118 struct tcmu_dev
*tcmu_dev
;
122 /* Can't use se_cmd->data_length when cleaning up expired cmds, because if
123 cmd has been completed then accessing se_cmd is off limits */
126 unsigned long deadline
;
128 #define TCMU_CMD_BIT_EXPIRED 0
132 static struct kmem_cache
*tcmu_cmd_cache
;
134 /* multicast group */
135 enum tcmu_multicast_groups
{
139 static const struct genl_multicast_group tcmu_mcgrps
[] = {
140 [TCMU_MCGRP_CONFIG
] = { .name
= "config", },
143 /* Our generic netlink family */
144 static struct genl_family tcmu_genl_family
= {
145 .id
= GENL_ID_GENERATE
,
149 .maxattr
= TCMU_ATTR_MAX
,
150 .mcgrps
= tcmu_mcgrps
,
151 .n_mcgrps
= ARRAY_SIZE(tcmu_mcgrps
),
154 static struct tcmu_cmd
*tcmu_alloc_cmd(struct se_cmd
*se_cmd
)
156 struct se_device
*se_dev
= se_cmd
->se_dev
;
157 struct tcmu_dev
*udev
= TCMU_DEV(se_dev
);
158 struct tcmu_cmd
*tcmu_cmd
;
161 tcmu_cmd
= kmem_cache_zalloc(tcmu_cmd_cache
, GFP_KERNEL
);
165 tcmu_cmd
->se_cmd
= se_cmd
;
166 tcmu_cmd
->tcmu_dev
= udev
;
167 tcmu_cmd
->data_length
= se_cmd
->data_length
;
169 tcmu_cmd
->deadline
= jiffies
+ msecs_to_jiffies(TCMU_TIME_OUT
);
171 idr_preload(GFP_KERNEL
);
172 spin_lock_irq(&udev
->commands_lock
);
173 cmd_id
= idr_alloc(&udev
->commands
, tcmu_cmd
, 0,
174 USHRT_MAX
, GFP_NOWAIT
);
175 spin_unlock_irq(&udev
->commands_lock
);
179 kmem_cache_free(tcmu_cmd_cache
, tcmu_cmd
);
182 tcmu_cmd
->cmd_id
= cmd_id
;
187 static inline void tcmu_flush_dcache_range(void *vaddr
, size_t size
)
189 unsigned long offset
= (unsigned long) vaddr
& ~PAGE_MASK
;
191 size
= round_up(size
+offset
, PAGE_SIZE
);
195 flush_dcache_page(virt_to_page(vaddr
));
201 * Some ring helper functions. We don't assume size is a power of 2 so
202 * we can't use circ_buf.h.
204 static inline size_t spc_used(size_t head
, size_t tail
, size_t size
)
206 int diff
= head
- tail
;
214 static inline size_t spc_free(size_t head
, size_t tail
, size_t size
)
216 /* Keep 1 byte unused or we can't tell full from empty */
217 return (size
- spc_used(head
, tail
, size
) - 1);
220 static inline size_t head_to_end(size_t head
, size_t size
)
225 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
228 * We can't queue a command until we have space available on the cmd ring *and* space
229 * space avail on the data ring.
231 * Called with ring lock held.
233 static bool is_ring_space_avail(struct tcmu_dev
*udev
, size_t cmd_size
, size_t data_needed
)
235 struct tcmu_mailbox
*mb
= udev
->mb_addr
;
240 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
242 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
245 * If cmd end-of-ring space is too small then we need space for a NOP plus
246 * original cmd - cmds are internally contiguous.
248 if (head_to_end(cmd_head
, udev
->cmdr_size
) >= cmd_size
)
249 cmd_needed
= cmd_size
;
251 cmd_needed
= cmd_size
+ head_to_end(cmd_head
, udev
->cmdr_size
);
253 space
= spc_free(cmd_head
, udev
->cmdr_last_cleaned
, udev
->cmdr_size
);
254 if (space
< cmd_needed
) {
255 pr_debug("no cmd space: %u %u %u\n", cmd_head
,
256 udev
->cmdr_last_cleaned
, udev
->cmdr_size
);
260 space
= spc_free(udev
->data_head
, udev
->data_tail
, udev
->data_size
);
261 if (space
< data_needed
) {
262 pr_debug("no data space: %zu %zu %zu\n", udev
->data_head
,
263 udev
->data_tail
, udev
->data_size
);
270 static int tcmu_queue_cmd_ring(struct tcmu_cmd
*tcmu_cmd
)
272 struct tcmu_dev
*udev
= tcmu_cmd
->tcmu_dev
;
273 struct se_cmd
*se_cmd
= tcmu_cmd
->se_cmd
;
274 size_t base_command_size
, command_size
;
275 struct tcmu_mailbox
*mb
;
276 struct tcmu_cmd_entry
*entry
;
278 struct scatterlist
*sg
;
284 if (test_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
))
288 * Must be a certain minimum size for response sense info, but
289 * also may be larger if the iov array is large.
291 * iovs = sgl_nents+1, for end-of-ring case, plus another 1
292 * b/c size == offsetof one-past-element.
294 base_command_size
= max(offsetof(struct tcmu_cmd_entry
,
295 req
.iov
[se_cmd
->t_data_nents
+ 2]),
296 sizeof(struct tcmu_cmd_entry
));
297 command_size
= base_command_size
298 + round_up(scsi_command_size(se_cmd
->t_task_cdb
), TCMU_OP_ALIGN_SIZE
);
300 WARN_ON(command_size
& (TCMU_OP_ALIGN_SIZE
-1));
302 spin_lock_irq(&udev
->cmdr_lock
);
305 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
306 if ((command_size
> (udev
->cmdr_size
/ 2))
307 || tcmu_cmd
->data_length
> (udev
->data_size
- 1))
308 pr_warn("TCMU: Request of size %zu/%zu may be too big for %u/%zu "
309 "cmd/data ring buffers\n", command_size
, tcmu_cmd
->data_length
,
310 udev
->cmdr_size
, udev
->data_size
);
312 while (!is_ring_space_avail(udev
, command_size
, tcmu_cmd
->data_length
)) {
316 prepare_to_wait(&udev
->wait_cmdr
, &__wait
, TASK_INTERRUPTIBLE
);
318 pr_debug("sleeping for ring space\n");
319 spin_unlock_irq(&udev
->cmdr_lock
);
320 ret
= schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT
));
321 finish_wait(&udev
->wait_cmdr
, &__wait
);
323 pr_warn("tcmu: command timed out\n");
327 spin_lock_irq(&udev
->cmdr_lock
);
329 /* We dropped cmdr_lock, cmd_head is stale */
330 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
333 /* Insert a PAD if end-of-ring space is too small */
334 if (head_to_end(cmd_head
, udev
->cmdr_size
) < command_size
) {
335 size_t pad_size
= head_to_end(cmd_head
, udev
->cmdr_size
);
337 entry
= (void *) mb
+ CMDR_OFF
+ cmd_head
;
338 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
339 tcmu_hdr_set_op(&entry
->hdr
.len_op
, TCMU_OP_PAD
);
340 tcmu_hdr_set_len(&entry
->hdr
.len_op
, pad_size
);
341 entry
->hdr
.cmd_id
= 0; /* not used for PAD */
342 entry
->hdr
.kflags
= 0;
343 entry
->hdr
.uflags
= 0;
345 UPDATE_HEAD(mb
->cmd_head
, pad_size
, udev
->cmdr_size
);
347 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
348 WARN_ON(cmd_head
!= 0);
351 entry
= (void *) mb
+ CMDR_OFF
+ cmd_head
;
352 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
353 tcmu_hdr_set_op(&entry
->hdr
.len_op
, TCMU_OP_CMD
);
354 tcmu_hdr_set_len(&entry
->hdr
.len_op
, command_size
);
355 entry
->hdr
.cmd_id
= tcmu_cmd
->cmd_id
;
356 entry
->hdr
.kflags
= 0;
357 entry
->hdr
.uflags
= 0;
360 * Fix up iovecs, and handle if allocation in data ring wrapped.
362 iov
= &entry
->req
.iov
[0];
363 for_each_sg(se_cmd
->t_data_sg
, sg
, se_cmd
->t_data_nents
, i
) {
364 size_t copy_bytes
= min((size_t)sg
->length
,
365 head_to_end(udev
->data_head
, udev
->data_size
));
366 void *from
= kmap_atomic(sg_page(sg
)) + sg
->offset
;
367 void *to
= (void *) mb
+ udev
->data_off
+ udev
->data_head
;
369 if (tcmu_cmd
->se_cmd
->data_direction
== DMA_TO_DEVICE
) {
370 memcpy(to
, from
, copy_bytes
);
371 tcmu_flush_dcache_range(to
, copy_bytes
);
374 /* Even iov_base is relative to mb_addr */
375 iov
->iov_len
= copy_bytes
;
376 iov
->iov_base
= (void __user
*) udev
->data_off
+
381 UPDATE_HEAD(udev
->data_head
, copy_bytes
, udev
->data_size
);
383 /* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */
384 if (sg
->length
!= copy_bytes
) {
386 copy_bytes
= sg
->length
- copy_bytes
;
388 iov
->iov_len
= copy_bytes
;
389 iov
->iov_base
= (void __user
*) udev
->data_off
+
392 if (se_cmd
->data_direction
== DMA_TO_DEVICE
) {
393 to
= (void *) mb
+ udev
->data_off
+ udev
->data_head
;
394 memcpy(to
, from
, copy_bytes
);
395 tcmu_flush_dcache_range(to
, copy_bytes
);
401 UPDATE_HEAD(udev
->data_head
, copy_bytes
, udev
->data_size
);
406 entry
->req
.iov_cnt
= iov_cnt
;
407 entry
->req
.iov_bidi_cnt
= 0;
408 entry
->req
.iov_dif_cnt
= 0;
410 /* All offsets relative to mb_addr, not start of entry! */
411 cdb_off
= CMDR_OFF
+ cmd_head
+ base_command_size
;
412 memcpy((void *) mb
+ cdb_off
, se_cmd
->t_task_cdb
, scsi_command_size(se_cmd
->t_task_cdb
));
413 entry
->req
.cdb_off
= cdb_off
;
414 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
416 UPDATE_HEAD(mb
->cmd_head
, command_size
, udev
->cmdr_size
);
417 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
419 spin_unlock_irq(&udev
->cmdr_lock
);
421 /* TODO: only if FLUSH and FUA? */
422 uio_event_notify(&udev
->uio_info
);
424 mod_timer(&udev
->timeout
,
425 round_jiffies_up(jiffies
+ msecs_to_jiffies(TCMU_TIME_OUT
)));
430 static int tcmu_queue_cmd(struct se_cmd
*se_cmd
)
432 struct se_device
*se_dev
= se_cmd
->se_dev
;
433 struct tcmu_dev
*udev
= TCMU_DEV(se_dev
);
434 struct tcmu_cmd
*tcmu_cmd
;
437 tcmu_cmd
= tcmu_alloc_cmd(se_cmd
);
441 ret
= tcmu_queue_cmd_ring(tcmu_cmd
);
443 pr_err("TCMU: Could not queue command\n");
444 spin_lock_irq(&udev
->commands_lock
);
445 idr_remove(&udev
->commands
, tcmu_cmd
->cmd_id
);
446 spin_unlock_irq(&udev
->commands_lock
);
448 kmem_cache_free(tcmu_cmd_cache
, tcmu_cmd
);
454 static void tcmu_handle_completion(struct tcmu_cmd
*cmd
, struct tcmu_cmd_entry
*entry
)
456 struct se_cmd
*se_cmd
= cmd
->se_cmd
;
457 struct tcmu_dev
*udev
= cmd
->tcmu_dev
;
459 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
)) {
460 /* cmd has been completed already from timeout, just reclaim data
462 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
466 if (entry
->hdr
.uflags
& TCMU_UFLAG_UNKNOWN_OP
) {
467 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
468 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
470 transport_generic_request_failure(cmd
->se_cmd
,
471 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
);
473 kmem_cache_free(tcmu_cmd_cache
, cmd
);
477 if (entry
->rsp
.scsi_status
== SAM_STAT_CHECK_CONDITION
) {
478 memcpy(se_cmd
->sense_buffer
, entry
->rsp
.sense_buffer
,
479 se_cmd
->scsi_sense_length
);
481 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
483 else if (se_cmd
->data_direction
== DMA_FROM_DEVICE
) {
484 struct scatterlist
*sg
;
487 /* It'd be easier to look at entry's iovec again, but UAM */
488 for_each_sg(se_cmd
->t_data_sg
, sg
, se_cmd
->t_data_nents
, i
) {
493 copy_bytes
= min((size_t)sg
->length
,
494 head_to_end(udev
->data_tail
, udev
->data_size
));
496 to
= kmap_atomic(sg_page(sg
)) + sg
->offset
;
497 WARN_ON(sg
->length
+ sg
->offset
> PAGE_SIZE
);
498 from
= (void *) udev
->mb_addr
+ udev
->data_off
+ udev
->data_tail
;
499 tcmu_flush_dcache_range(from
, copy_bytes
);
500 memcpy(to
, from
, copy_bytes
);
502 UPDATE_HEAD(udev
->data_tail
, copy_bytes
, udev
->data_size
);
504 /* Uh oh, wrapped the data buffer for this sg's data */
505 if (sg
->length
!= copy_bytes
) {
506 from
= (void *) udev
->mb_addr
+ udev
->data_off
+ udev
->data_tail
;
507 WARN_ON(udev
->data_tail
);
509 copy_bytes
= sg
->length
- copy_bytes
;
510 tcmu_flush_dcache_range(from
, copy_bytes
);
511 memcpy(to
, from
, copy_bytes
);
513 UPDATE_HEAD(udev
->data_tail
, copy_bytes
, udev
->data_size
);
519 } else if (se_cmd
->data_direction
== DMA_TO_DEVICE
) {
520 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
522 pr_warn("TCMU: data direction was %d!\n", se_cmd
->data_direction
);
525 target_complete_cmd(cmd
->se_cmd
, entry
->rsp
.scsi_status
);
528 kmem_cache_free(tcmu_cmd_cache
, cmd
);
531 static unsigned int tcmu_handle_completions(struct tcmu_dev
*udev
)
533 struct tcmu_mailbox
*mb
;
538 if (test_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
)) {
539 pr_err("ring broken, not handling completions\n");
543 spin_lock_irqsave(&udev
->cmdr_lock
, flags
);
546 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
548 while (udev
->cmdr_last_cleaned
!= ACCESS_ONCE(mb
->cmd_tail
)) {
550 struct tcmu_cmd_entry
*entry
= (void *) mb
+ CMDR_OFF
+ udev
->cmdr_last_cleaned
;
551 struct tcmu_cmd
*cmd
;
553 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
555 if (tcmu_hdr_get_op(entry
->hdr
.len_op
) == TCMU_OP_PAD
) {
556 UPDATE_HEAD(udev
->cmdr_last_cleaned
,
557 tcmu_hdr_get_len(entry
->hdr
.len_op
),
561 WARN_ON(tcmu_hdr_get_op(entry
->hdr
.len_op
) != TCMU_OP_CMD
);
563 spin_lock(&udev
->commands_lock
);
564 cmd
= idr_find(&udev
->commands
, entry
->hdr
.cmd_id
);
566 idr_remove(&udev
->commands
, cmd
->cmd_id
);
567 spin_unlock(&udev
->commands_lock
);
570 pr_err("cmd_id not found, ring is broken\n");
571 set_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
);
575 tcmu_handle_completion(cmd
, entry
);
577 UPDATE_HEAD(udev
->cmdr_last_cleaned
,
578 tcmu_hdr_get_len(entry
->hdr
.len_op
),
584 if (mb
->cmd_tail
== mb
->cmd_head
)
585 del_timer(&udev
->timeout
); /* no more pending cmds */
587 spin_unlock_irqrestore(&udev
->cmdr_lock
, flags
);
589 wake_up(&udev
->wait_cmdr
);
594 static int tcmu_check_expired_cmd(int id
, void *p
, void *data
)
596 struct tcmu_cmd
*cmd
= p
;
598 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
))
601 if (!time_after(cmd
->deadline
, jiffies
))
604 set_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
);
605 target_complete_cmd(cmd
->se_cmd
, SAM_STAT_CHECK_CONDITION
);
608 kmem_cache_free(tcmu_cmd_cache
, cmd
);
613 static void tcmu_device_timedout(unsigned long data
)
615 struct tcmu_dev
*udev
= (struct tcmu_dev
*)data
;
619 handled
= tcmu_handle_completions(udev
);
621 pr_warn("%d completions handled from timeout\n", handled
);
623 spin_lock_irqsave(&udev
->commands_lock
, flags
);
624 idr_for_each(&udev
->commands
, tcmu_check_expired_cmd
, NULL
);
625 spin_unlock_irqrestore(&udev
->commands_lock
, flags
);
628 * We don't need to wakeup threads on wait_cmdr since they have their
633 static int tcmu_attach_hba(struct se_hba
*hba
, u32 host_id
)
635 struct tcmu_hba
*tcmu_hba
;
637 tcmu_hba
= kzalloc(sizeof(struct tcmu_hba
), GFP_KERNEL
);
641 tcmu_hba
->host_id
= host_id
;
642 hba
->hba_ptr
= tcmu_hba
;
647 static void tcmu_detach_hba(struct se_hba
*hba
)
653 static struct se_device
*tcmu_alloc_device(struct se_hba
*hba
, const char *name
)
655 struct tcmu_dev
*udev
;
657 udev
= kzalloc(sizeof(struct tcmu_dev
), GFP_KERNEL
);
661 udev
->name
= kstrdup(name
, GFP_KERNEL
);
669 init_waitqueue_head(&udev
->wait_cmdr
);
670 spin_lock_init(&udev
->cmdr_lock
);
672 idr_init(&udev
->commands
);
673 spin_lock_init(&udev
->commands_lock
);
675 setup_timer(&udev
->timeout
, tcmu_device_timedout
,
676 (unsigned long)udev
);
678 return &udev
->se_dev
;
681 static int tcmu_irqcontrol(struct uio_info
*info
, s32 irq_on
)
683 struct tcmu_dev
*tcmu_dev
= container_of(info
, struct tcmu_dev
, uio_info
);
685 tcmu_handle_completions(tcmu_dev
);
691 * mmap code from uio.c. Copied here because we want to hook mmap()
692 * and this stuff must come along.
694 static int tcmu_find_mem_index(struct vm_area_struct
*vma
)
696 struct tcmu_dev
*udev
= vma
->vm_private_data
;
697 struct uio_info
*info
= &udev
->uio_info
;
699 if (vma
->vm_pgoff
< MAX_UIO_MAPS
) {
700 if (info
->mem
[vma
->vm_pgoff
].size
== 0)
702 return (int)vma
->vm_pgoff
;
707 static int tcmu_vma_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
709 struct tcmu_dev
*udev
= vma
->vm_private_data
;
710 struct uio_info
*info
= &udev
->uio_info
;
712 unsigned long offset
;
715 int mi
= tcmu_find_mem_index(vma
);
717 return VM_FAULT_SIGBUS
;
720 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
723 offset
= (vmf
->pgoff
- mi
) << PAGE_SHIFT
;
725 addr
= (void *)(unsigned long)info
->mem
[mi
].addr
+ offset
;
726 if (info
->mem
[mi
].memtype
== UIO_MEM_LOGICAL
)
727 page
= virt_to_page(addr
);
729 page
= vmalloc_to_page(addr
);
735 static const struct vm_operations_struct tcmu_vm_ops
= {
736 .fault
= tcmu_vma_fault
,
739 static int tcmu_mmap(struct uio_info
*info
, struct vm_area_struct
*vma
)
741 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
743 vma
->vm_flags
|= VM_DONTEXPAND
| VM_DONTDUMP
;
744 vma
->vm_ops
= &tcmu_vm_ops
;
746 vma
->vm_private_data
= udev
;
748 /* Ensure the mmap is exactly the right size */
749 if (vma_pages(vma
) != (TCMU_RING_SIZE
>> PAGE_SHIFT
))
755 static int tcmu_open(struct uio_info
*info
, struct inode
*inode
)
757 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
759 /* O_EXCL not supported for char devs, so fake it? */
760 if (test_and_set_bit(TCMU_DEV_BIT_OPEN
, &udev
->flags
))
768 static int tcmu_release(struct uio_info
*info
, struct inode
*inode
)
770 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
772 clear_bit(TCMU_DEV_BIT_OPEN
, &udev
->flags
);
779 static int tcmu_netlink_event(enum tcmu_genl_cmd cmd
, const char *name
, int minor
)
785 skb
= genlmsg_new(NLMSG_GOODSIZE
, GFP_KERNEL
);
789 msg_header
= genlmsg_put(skb
, 0, 0, &tcmu_genl_family
, 0, cmd
);
793 ret
= nla_put_string(skb
, TCMU_ATTR_DEVICE
, name
);
797 ret
= nla_put_u32(skb
, TCMU_ATTR_MINOR
, minor
);
801 genlmsg_end(skb
, msg_header
);
803 ret
= genlmsg_multicast(&tcmu_genl_family
, skb
, 0,
804 TCMU_MCGRP_CONFIG
, GFP_KERNEL
);
806 /* We don't care if no one is listening */
816 static int tcmu_configure_device(struct se_device
*dev
)
818 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
819 struct tcmu_hba
*hba
= udev
->hba
->hba_ptr
;
820 struct uio_info
*info
;
821 struct tcmu_mailbox
*mb
;
827 info
= &udev
->uio_info
;
829 size
= snprintf(NULL
, 0, "tcm-user/%u/%s/%s", hba
->host_id
, udev
->name
,
831 size
+= 1; /* for \0 */
832 str
= kmalloc(size
, GFP_KERNEL
);
836 used
= snprintf(str
, size
, "tcm-user/%u/%s", hba
->host_id
, udev
->name
);
838 if (udev
->dev_config
[0])
839 snprintf(str
+ used
, size
- used
, "/%s", udev
->dev_config
);
843 udev
->mb_addr
= vzalloc(TCMU_RING_SIZE
);
844 if (!udev
->mb_addr
) {
849 /* mailbox fits in first part of CMDR space */
850 udev
->cmdr_size
= CMDR_SIZE
- CMDR_OFF
;
851 udev
->data_off
= CMDR_SIZE
;
852 udev
->data_size
= TCMU_RING_SIZE
- CMDR_SIZE
;
855 mb
->version
= TCMU_MAILBOX_VERSION
;
856 mb
->cmdr_off
= CMDR_OFF
;
857 mb
->cmdr_size
= udev
->cmdr_size
;
859 WARN_ON(!PAGE_ALIGNED(udev
->data_off
));
860 WARN_ON(udev
->data_size
% PAGE_SIZE
);
862 info
->version
= xstr(TCMU_MAILBOX_VERSION
);
864 info
->mem
[0].name
= "tcm-user command & data buffer";
865 info
->mem
[0].addr
= (phys_addr_t
) udev
->mb_addr
;
866 info
->mem
[0].size
= TCMU_RING_SIZE
;
867 info
->mem
[0].memtype
= UIO_MEM_VIRTUAL
;
869 info
->irqcontrol
= tcmu_irqcontrol
;
870 info
->irq
= UIO_IRQ_CUSTOM
;
872 info
->mmap
= tcmu_mmap
;
873 info
->open
= tcmu_open
;
874 info
->release
= tcmu_release
;
876 ret
= uio_register_device(tcmu_root_device
, info
);
880 /* Other attributes can be configured in userspace */
881 dev
->dev_attrib
.hw_block_size
= 512;
882 dev
->dev_attrib
.hw_max_sectors
= 128;
883 dev
->dev_attrib
.hw_queue_depth
= 128;
885 ret
= tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE
, udev
->uio_info
.name
,
886 udev
->uio_info
.uio_dev
->minor
);
893 uio_unregister_device(&udev
->uio_info
);
895 vfree(udev
->mb_addr
);
902 static int tcmu_check_pending_cmd(int id
, void *p
, void *data
)
904 struct tcmu_cmd
*cmd
= p
;
906 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
))
911 static void tcmu_free_device(struct se_device
*dev
)
913 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
916 del_timer_sync(&udev
->timeout
);
918 vfree(udev
->mb_addr
);
920 /* Upper layer should drain all requests before calling this */
921 spin_lock_irq(&udev
->commands_lock
);
922 i
= idr_for_each(&udev
->commands
, tcmu_check_pending_cmd
, NULL
);
923 idr_destroy(&udev
->commands
);
924 spin_unlock_irq(&udev
->commands_lock
);
927 /* Device was configured */
928 if (udev
->uio_info
.uio_dev
) {
929 tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE
, udev
->uio_info
.name
,
930 udev
->uio_info
.uio_dev
->minor
);
932 uio_unregister_device(&udev
->uio_info
);
933 kfree(udev
->uio_info
.name
);
941 Opt_dev_config
, Opt_dev_size
, Opt_hw_block_size
, Opt_err
,
944 static match_table_t tokens
= {
945 {Opt_dev_config
, "dev_config=%s"},
946 {Opt_dev_size
, "dev_size=%u"},
947 {Opt_hw_block_size
, "hw_block_size=%u"},
951 static ssize_t
tcmu_set_configfs_dev_params(struct se_device
*dev
,
952 const char *page
, ssize_t count
)
954 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
955 char *orig
, *ptr
, *opts
, *arg_p
;
956 substring_t args
[MAX_OPT_ARGS
];
958 unsigned long tmp_ul
;
960 opts
= kstrdup(page
, GFP_KERNEL
);
966 while ((ptr
= strsep(&opts
, ",\n")) != NULL
) {
970 token
= match_token(ptr
, tokens
, args
);
973 if (match_strlcpy(udev
->dev_config
, &args
[0],
974 TCMU_CONFIG_LEN
) == 0) {
978 pr_debug("TCMU: Referencing Path: %s\n", udev
->dev_config
);
981 arg_p
= match_strdup(&args
[0]);
986 ret
= kstrtoul(arg_p
, 0, (unsigned long *) &udev
->dev_size
);
989 pr_err("kstrtoul() failed for dev_size=\n");
991 case Opt_hw_block_size
:
992 arg_p
= match_strdup(&args
[0]);
997 ret
= kstrtoul(arg_p
, 0, &tmp_ul
);
1000 pr_err("kstrtoul() failed for hw_block_size=\n");
1004 pr_err("hw_block_size must be nonzero\n");
1007 dev
->dev_attrib
.hw_block_size
= tmp_ul
;
1015 return (!ret
) ? count
: ret
;
1018 static ssize_t
tcmu_show_configfs_dev_params(struct se_device
*dev
, char *b
)
1020 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1023 bl
= sprintf(b
+ bl
, "Config: %s ",
1024 udev
->dev_config
[0] ? udev
->dev_config
: "NULL");
1025 bl
+= sprintf(b
+ bl
, "Size: %zu\n", udev
->dev_size
);
1030 static sector_t
tcmu_get_blocks(struct se_device
*dev
)
1032 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1034 return div_u64(udev
->dev_size
- dev
->dev_attrib
.block_size
,
1035 dev
->dev_attrib
.block_size
);
1038 static sense_reason_t
1039 tcmu_pass_op(struct se_cmd
*se_cmd
)
1041 int ret
= tcmu_queue_cmd(se_cmd
);
1044 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
1046 return TCM_NO_SENSE
;
1049 static sense_reason_t
1050 tcmu_parse_cdb(struct se_cmd
*cmd
)
1052 return passthrough_parse_cdb(cmd
, tcmu_pass_op
);
1055 DEF_TB_DEV_ATTRIB_RO(tcmu
, hw_pi_prot_type
);
1056 TB_DEV_ATTR_RO(tcmu
, hw_pi_prot_type
);
1058 DEF_TB_DEV_ATTRIB_RO(tcmu
, hw_block_size
);
1059 TB_DEV_ATTR_RO(tcmu
, hw_block_size
);
1061 DEF_TB_DEV_ATTRIB_RO(tcmu
, hw_max_sectors
);
1062 TB_DEV_ATTR_RO(tcmu
, hw_max_sectors
);
1064 DEF_TB_DEV_ATTRIB_RO(tcmu
, hw_queue_depth
);
1065 TB_DEV_ATTR_RO(tcmu
, hw_queue_depth
);
1067 static struct configfs_attribute
*tcmu_backend_dev_attrs
[] = {
1068 &tcmu_dev_attrib_hw_pi_prot_type
.attr
,
1069 &tcmu_dev_attrib_hw_block_size
.attr
,
1070 &tcmu_dev_attrib_hw_max_sectors
.attr
,
1071 &tcmu_dev_attrib_hw_queue_depth
.attr
,
1075 static struct se_subsystem_api tcmu_template
= {
1077 .inquiry_prod
= "USER",
1078 .inquiry_rev
= TCMU_VERSION
,
1079 .owner
= THIS_MODULE
,
1080 .transport_flags
= TRANSPORT_FLAG_PASSTHROUGH
,
1081 .attach_hba
= tcmu_attach_hba
,
1082 .detach_hba
= tcmu_detach_hba
,
1083 .alloc_device
= tcmu_alloc_device
,
1084 .configure_device
= tcmu_configure_device
,
1085 .free_device
= tcmu_free_device
,
1086 .parse_cdb
= tcmu_parse_cdb
,
1087 .set_configfs_dev_params
= tcmu_set_configfs_dev_params
,
1088 .show_configfs_dev_params
= tcmu_show_configfs_dev_params
,
1089 .get_device_type
= sbc_get_device_type
,
1090 .get_blocks
= tcmu_get_blocks
,
1093 static int __init
tcmu_module_init(void)
1095 struct target_backend_cits
*tbc
= &tcmu_template
.tb_cits
;
1098 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry
) % TCMU_OP_ALIGN_SIZE
) != 0);
1100 tcmu_cmd_cache
= kmem_cache_create("tcmu_cmd_cache",
1101 sizeof(struct tcmu_cmd
),
1102 __alignof__(struct tcmu_cmd
),
1104 if (!tcmu_cmd_cache
)
1107 tcmu_root_device
= root_device_register("tcm_user");
1108 if (IS_ERR(tcmu_root_device
)) {
1109 ret
= PTR_ERR(tcmu_root_device
);
1110 goto out_free_cache
;
1113 ret
= genl_register_family(&tcmu_genl_family
);
1115 goto out_unreg_device
;
1118 target_core_setup_sub_cits(&tcmu_template
);
1119 tbc
->tb_dev_attrib_cit
.ct_attrs
= tcmu_backend_dev_attrs
;
1121 ret
= transport_subsystem_register(&tcmu_template
);
1123 goto out_unreg_genl
;
1128 genl_unregister_family(&tcmu_genl_family
);
1130 root_device_unregister(tcmu_root_device
);
1132 kmem_cache_destroy(tcmu_cmd_cache
);
1137 static void __exit
tcmu_module_exit(void)
1139 transport_subsystem_release(&tcmu_template
);
1140 genl_unregister_family(&tcmu_genl_family
);
1141 root_device_unregister(tcmu_root_device
);
1142 kmem_cache_destroy(tcmu_cmd_cache
);
1145 MODULE_DESCRIPTION("TCM USER subsystem plugin");
1146 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
1147 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
1148 MODULE_LICENSE("GPL");
1150 module_init(tcmu_module_init
);
1151 module_exit(tcmu_module_exit
);