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/kernel.h>
23 #include <linux/timer.h>
24 #include <linux/parser.h>
25 #include <linux/vmalloc.h>
26 #include <linux/uio_driver.h>
27 #include <net/genetlink.h>
28 #include <scsi/scsi_common.h>
29 #include <scsi/scsi_proto.h>
30 #include <target/target_core_base.h>
31 #include <target/target_core_fabric.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_backend_configfs.h>
35 #include <linux/target_core_user.h>
38 * Define a shared-memory interface for LIO to pass SCSI commands and
39 * data to userspace for processing. This is to allow backends that
40 * are too complex for in-kernel support to be possible.
42 * It uses the UIO framework to do a lot of the device-creation and
43 * introspection work for us.
45 * See the .h file for how the ring is laid out. Note that while the
46 * command ring is defined, the particulars of the data area are
47 * not. Offset values in the command entry point to other locations
48 * internal to the mmap()ed area. There is separate space outside the
49 * command ring for data buffers. This leaves maximum flexibility for
50 * moving buffer allocations, or even page flipping or other
51 * allocation techniques, without altering the command ring layout.
54 * The user process must be assumed to be malicious. There's no way to
55 * prevent it breaking the command ring protocol if it wants, but in
56 * order to prevent other issues we must only ever read *data* from
57 * the shared memory area, not offsets or sizes. This applies to
58 * command ring entries as well as the mailbox. Extra code needed for
59 * this may have a 'UAM' comment.
63 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
65 #define CMDR_SIZE (16 * 4096)
66 #define DATA_SIZE (257 * 4096)
68 #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
70 static struct device
*tcmu_root_device
;
76 #define TCMU_CONFIG_LEN 256
79 struct se_device se_dev
;
84 #define TCMU_DEV_BIT_OPEN 0
85 #define TCMU_DEV_BIT_BROKEN 1
88 struct uio_info uio_info
;
90 struct tcmu_mailbox
*mb_addr
;
93 u32 cmdr_last_cleaned
;
94 /* Offset of data ring from start of mb */
97 /* Ring head + tail values. */
98 /* Must add data_off and mb_addr to get the address */
102 wait_queue_head_t wait_cmdr
;
103 /* TODO should this be a mutex? */
104 spinlock_t cmdr_lock
;
107 spinlock_t commands_lock
;
109 struct timer_list timeout
;
111 char dev_config
[TCMU_CONFIG_LEN
];
114 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
116 #define CMDR_OFF sizeof(struct tcmu_mailbox)
119 struct se_cmd
*se_cmd
;
120 struct tcmu_dev
*tcmu_dev
;
124 /* Can't use se_cmd->data_length when cleaning up expired cmds, because if
125 cmd has been completed then accessing se_cmd is off limits */
128 unsigned long deadline
;
130 #define TCMU_CMD_BIT_EXPIRED 0
134 static struct kmem_cache
*tcmu_cmd_cache
;
136 /* multicast group */
137 enum tcmu_multicast_groups
{
141 static const struct genl_multicast_group tcmu_mcgrps
[] = {
142 [TCMU_MCGRP_CONFIG
] = { .name
= "config", },
145 /* Our generic netlink family */
146 static struct genl_family tcmu_genl_family
= {
147 .id
= GENL_ID_GENERATE
,
151 .maxattr
= TCMU_ATTR_MAX
,
152 .mcgrps
= tcmu_mcgrps
,
153 .n_mcgrps
= ARRAY_SIZE(tcmu_mcgrps
),
156 static struct tcmu_cmd
*tcmu_alloc_cmd(struct se_cmd
*se_cmd
)
158 struct se_device
*se_dev
= se_cmd
->se_dev
;
159 struct tcmu_dev
*udev
= TCMU_DEV(se_dev
);
160 struct tcmu_cmd
*tcmu_cmd
;
163 tcmu_cmd
= kmem_cache_zalloc(tcmu_cmd_cache
, GFP_KERNEL
);
167 tcmu_cmd
->se_cmd
= se_cmd
;
168 tcmu_cmd
->tcmu_dev
= udev
;
169 tcmu_cmd
->data_length
= se_cmd
->data_length
;
171 tcmu_cmd
->deadline
= jiffies
+ msecs_to_jiffies(TCMU_TIME_OUT
);
173 idr_preload(GFP_KERNEL
);
174 spin_lock_irq(&udev
->commands_lock
);
175 cmd_id
= idr_alloc(&udev
->commands
, tcmu_cmd
, 0,
176 USHRT_MAX
, GFP_NOWAIT
);
177 spin_unlock_irq(&udev
->commands_lock
);
181 kmem_cache_free(tcmu_cmd_cache
, tcmu_cmd
);
184 tcmu_cmd
->cmd_id
= cmd_id
;
189 static inline void tcmu_flush_dcache_range(void *vaddr
, size_t size
)
191 unsigned long offset
= (unsigned long) vaddr
& ~PAGE_MASK
;
193 size
= round_up(size
+offset
, PAGE_SIZE
);
197 flush_dcache_page(virt_to_page(vaddr
));
203 * Some ring helper functions. We don't assume size is a power of 2 so
204 * we can't use circ_buf.h.
206 static inline size_t spc_used(size_t head
, size_t tail
, size_t size
)
208 int diff
= head
- tail
;
216 static inline size_t spc_free(size_t head
, size_t tail
, size_t size
)
218 /* Keep 1 byte unused or we can't tell full from empty */
219 return (size
- spc_used(head
, tail
, size
) - 1);
222 static inline size_t head_to_end(size_t head
, size_t size
)
227 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
230 * We can't queue a command until we have space available on the cmd ring *and* space
231 * space avail on the data ring.
233 * Called with ring lock held.
235 static bool is_ring_space_avail(struct tcmu_dev
*udev
, size_t cmd_size
, size_t data_needed
)
237 struct tcmu_mailbox
*mb
= udev
->mb_addr
;
242 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
244 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
247 * If cmd end-of-ring space is too small then we need space for a NOP plus
248 * original cmd - cmds are internally contiguous.
250 if (head_to_end(cmd_head
, udev
->cmdr_size
) >= cmd_size
)
251 cmd_needed
= cmd_size
;
253 cmd_needed
= cmd_size
+ head_to_end(cmd_head
, udev
->cmdr_size
);
255 space
= spc_free(cmd_head
, udev
->cmdr_last_cleaned
, udev
->cmdr_size
);
256 if (space
< cmd_needed
) {
257 pr_debug("no cmd space: %u %u %u\n", cmd_head
,
258 udev
->cmdr_last_cleaned
, udev
->cmdr_size
);
262 space
= spc_free(udev
->data_head
, udev
->data_tail
, udev
->data_size
);
263 if (space
< data_needed
) {
264 pr_debug("no data space: %zu %zu %zu\n", udev
->data_head
,
265 udev
->data_tail
, udev
->data_size
);
272 static int tcmu_queue_cmd_ring(struct tcmu_cmd
*tcmu_cmd
)
274 struct tcmu_dev
*udev
= tcmu_cmd
->tcmu_dev
;
275 struct se_cmd
*se_cmd
= tcmu_cmd
->se_cmd
;
276 size_t base_command_size
, command_size
;
277 struct tcmu_mailbox
*mb
;
278 struct tcmu_cmd_entry
*entry
;
280 struct scatterlist
*sg
;
286 if (test_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
))
290 * Must be a certain minimum size for response sense info, but
291 * also may be larger if the iov array is large.
293 * iovs = sgl_nents+1, for end-of-ring case, plus another 1
294 * b/c size == offsetof one-past-element.
296 base_command_size
= max(offsetof(struct tcmu_cmd_entry
,
297 req
.iov
[se_cmd
->t_data_nents
+ 2]),
298 sizeof(struct tcmu_cmd_entry
));
299 command_size
= base_command_size
300 + round_up(scsi_command_size(se_cmd
->t_task_cdb
), TCMU_OP_ALIGN_SIZE
);
302 WARN_ON(command_size
& (TCMU_OP_ALIGN_SIZE
-1));
304 spin_lock_irq(&udev
->cmdr_lock
);
307 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
308 if ((command_size
> (udev
->cmdr_size
/ 2))
309 || tcmu_cmd
->data_length
> (udev
->data_size
- 1))
310 pr_warn("TCMU: Request of size %zu/%zu may be too big for %u/%zu "
311 "cmd/data ring buffers\n", command_size
, tcmu_cmd
->data_length
,
312 udev
->cmdr_size
, udev
->data_size
);
314 while (!is_ring_space_avail(udev
, command_size
, tcmu_cmd
->data_length
)) {
318 prepare_to_wait(&udev
->wait_cmdr
, &__wait
, TASK_INTERRUPTIBLE
);
320 pr_debug("sleeping for ring space\n");
321 spin_unlock_irq(&udev
->cmdr_lock
);
322 ret
= schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT
));
323 finish_wait(&udev
->wait_cmdr
, &__wait
);
325 pr_warn("tcmu: command timed out\n");
329 spin_lock_irq(&udev
->cmdr_lock
);
331 /* We dropped cmdr_lock, cmd_head is stale */
332 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
335 /* Insert a PAD if end-of-ring space is too small */
336 if (head_to_end(cmd_head
, udev
->cmdr_size
) < command_size
) {
337 size_t pad_size
= head_to_end(cmd_head
, udev
->cmdr_size
);
339 entry
= (void *) mb
+ CMDR_OFF
+ cmd_head
;
340 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
341 tcmu_hdr_set_op(&entry
->hdr
.len_op
, TCMU_OP_PAD
);
342 tcmu_hdr_set_len(&entry
->hdr
.len_op
, pad_size
);
343 entry
->hdr
.cmd_id
= 0; /* not used for PAD */
344 entry
->hdr
.kflags
= 0;
345 entry
->hdr
.uflags
= 0;
347 UPDATE_HEAD(mb
->cmd_head
, pad_size
, udev
->cmdr_size
);
349 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
350 WARN_ON(cmd_head
!= 0);
353 entry
= (void *) mb
+ CMDR_OFF
+ cmd_head
;
354 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
355 tcmu_hdr_set_op(&entry
->hdr
.len_op
, TCMU_OP_CMD
);
356 tcmu_hdr_set_len(&entry
->hdr
.len_op
, command_size
);
357 entry
->hdr
.cmd_id
= tcmu_cmd
->cmd_id
;
358 entry
->hdr
.kflags
= 0;
359 entry
->hdr
.uflags
= 0;
362 * Fix up iovecs, and handle if allocation in data ring wrapped.
364 iov
= &entry
->req
.iov
[0];
365 for_each_sg(se_cmd
->t_data_sg
, sg
, se_cmd
->t_data_nents
, i
) {
366 size_t copy_bytes
= min((size_t)sg
->length
,
367 head_to_end(udev
->data_head
, udev
->data_size
));
368 void *from
= kmap_atomic(sg_page(sg
)) + sg
->offset
;
369 void *to
= (void *) mb
+ udev
->data_off
+ udev
->data_head
;
371 if (tcmu_cmd
->se_cmd
->data_direction
== DMA_TO_DEVICE
) {
372 memcpy(to
, from
, copy_bytes
);
373 tcmu_flush_dcache_range(to
, copy_bytes
);
376 /* Even iov_base is relative to mb_addr */
377 iov
->iov_len
= copy_bytes
;
378 iov
->iov_base
= (void __user
*) udev
->data_off
+
383 UPDATE_HEAD(udev
->data_head
, copy_bytes
, udev
->data_size
);
385 /* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */
386 if (sg
->length
!= copy_bytes
) {
388 copy_bytes
= sg
->length
- copy_bytes
;
390 iov
->iov_len
= copy_bytes
;
391 iov
->iov_base
= (void __user
*) udev
->data_off
+
394 if (se_cmd
->data_direction
== DMA_TO_DEVICE
) {
395 to
= (void *) mb
+ udev
->data_off
+ udev
->data_head
;
396 memcpy(to
, from
, copy_bytes
);
397 tcmu_flush_dcache_range(to
, copy_bytes
);
403 UPDATE_HEAD(udev
->data_head
, copy_bytes
, udev
->data_size
);
408 entry
->req
.iov_cnt
= iov_cnt
;
409 entry
->req
.iov_bidi_cnt
= 0;
410 entry
->req
.iov_dif_cnt
= 0;
412 /* All offsets relative to mb_addr, not start of entry! */
413 cdb_off
= CMDR_OFF
+ cmd_head
+ base_command_size
;
414 memcpy((void *) mb
+ cdb_off
, se_cmd
->t_task_cdb
, scsi_command_size(se_cmd
->t_task_cdb
));
415 entry
->req
.cdb_off
= cdb_off
;
416 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
418 UPDATE_HEAD(mb
->cmd_head
, command_size
, udev
->cmdr_size
);
419 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
421 spin_unlock_irq(&udev
->cmdr_lock
);
423 /* TODO: only if FLUSH and FUA? */
424 uio_event_notify(&udev
->uio_info
);
426 mod_timer(&udev
->timeout
,
427 round_jiffies_up(jiffies
+ msecs_to_jiffies(TCMU_TIME_OUT
)));
432 static int tcmu_queue_cmd(struct se_cmd
*se_cmd
)
434 struct se_device
*se_dev
= se_cmd
->se_dev
;
435 struct tcmu_dev
*udev
= TCMU_DEV(se_dev
);
436 struct tcmu_cmd
*tcmu_cmd
;
439 tcmu_cmd
= tcmu_alloc_cmd(se_cmd
);
443 ret
= tcmu_queue_cmd_ring(tcmu_cmd
);
445 pr_err("TCMU: Could not queue command\n");
446 spin_lock_irq(&udev
->commands_lock
);
447 idr_remove(&udev
->commands
, tcmu_cmd
->cmd_id
);
448 spin_unlock_irq(&udev
->commands_lock
);
450 kmem_cache_free(tcmu_cmd_cache
, tcmu_cmd
);
456 static void tcmu_handle_completion(struct tcmu_cmd
*cmd
, struct tcmu_cmd_entry
*entry
)
458 struct se_cmd
*se_cmd
= cmd
->se_cmd
;
459 struct tcmu_dev
*udev
= cmd
->tcmu_dev
;
461 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
)) {
462 /* cmd has been completed already from timeout, just reclaim data
464 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
468 if (entry
->hdr
.uflags
& TCMU_UFLAG_UNKNOWN_OP
) {
469 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
470 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
472 transport_generic_request_failure(cmd
->se_cmd
,
473 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
);
475 kmem_cache_free(tcmu_cmd_cache
, cmd
);
479 if (entry
->rsp
.scsi_status
== SAM_STAT_CHECK_CONDITION
) {
480 memcpy(se_cmd
->sense_buffer
, entry
->rsp
.sense_buffer
,
481 se_cmd
->scsi_sense_length
);
483 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
485 else if (se_cmd
->data_direction
== DMA_FROM_DEVICE
) {
486 struct scatterlist
*sg
;
489 /* It'd be easier to look at entry's iovec again, but UAM */
490 for_each_sg(se_cmd
->t_data_sg
, sg
, se_cmd
->t_data_nents
, i
) {
495 copy_bytes
= min((size_t)sg
->length
,
496 head_to_end(udev
->data_tail
, udev
->data_size
));
498 to
= kmap_atomic(sg_page(sg
)) + sg
->offset
;
499 WARN_ON(sg
->length
+ sg
->offset
> PAGE_SIZE
);
500 from
= (void *) udev
->mb_addr
+ udev
->data_off
+ udev
->data_tail
;
501 tcmu_flush_dcache_range(from
, copy_bytes
);
502 memcpy(to
, from
, copy_bytes
);
504 UPDATE_HEAD(udev
->data_tail
, copy_bytes
, udev
->data_size
);
506 /* Uh oh, wrapped the data buffer for this sg's data */
507 if (sg
->length
!= copy_bytes
) {
508 from
= (void *) udev
->mb_addr
+ udev
->data_off
+ udev
->data_tail
;
509 WARN_ON(udev
->data_tail
);
511 copy_bytes
= sg
->length
- copy_bytes
;
512 tcmu_flush_dcache_range(from
, copy_bytes
);
513 memcpy(to
, from
, copy_bytes
);
515 UPDATE_HEAD(udev
->data_tail
, copy_bytes
, udev
->data_size
);
521 } else if (se_cmd
->data_direction
== DMA_TO_DEVICE
) {
522 UPDATE_HEAD(udev
->data_tail
, cmd
->data_length
, udev
->data_size
);
524 pr_warn("TCMU: data direction was %d!\n", se_cmd
->data_direction
);
527 target_complete_cmd(cmd
->se_cmd
, entry
->rsp
.scsi_status
);
530 kmem_cache_free(tcmu_cmd_cache
, cmd
);
533 static unsigned int tcmu_handle_completions(struct tcmu_dev
*udev
)
535 struct tcmu_mailbox
*mb
;
540 if (test_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
)) {
541 pr_err("ring broken, not handling completions\n");
545 spin_lock_irqsave(&udev
->cmdr_lock
, flags
);
548 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
550 while (udev
->cmdr_last_cleaned
!= ACCESS_ONCE(mb
->cmd_tail
)) {
552 struct tcmu_cmd_entry
*entry
= (void *) mb
+ CMDR_OFF
+ udev
->cmdr_last_cleaned
;
553 struct tcmu_cmd
*cmd
;
555 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
557 if (tcmu_hdr_get_op(entry
->hdr
.len_op
) == TCMU_OP_PAD
) {
558 UPDATE_HEAD(udev
->cmdr_last_cleaned
,
559 tcmu_hdr_get_len(entry
->hdr
.len_op
),
563 WARN_ON(tcmu_hdr_get_op(entry
->hdr
.len_op
) != TCMU_OP_CMD
);
565 spin_lock(&udev
->commands_lock
);
566 cmd
= idr_find(&udev
->commands
, entry
->hdr
.cmd_id
);
568 idr_remove(&udev
->commands
, cmd
->cmd_id
);
569 spin_unlock(&udev
->commands_lock
);
572 pr_err("cmd_id not found, ring is broken\n");
573 set_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
);
577 tcmu_handle_completion(cmd
, entry
);
579 UPDATE_HEAD(udev
->cmdr_last_cleaned
,
580 tcmu_hdr_get_len(entry
->hdr
.len_op
),
586 if (mb
->cmd_tail
== mb
->cmd_head
)
587 del_timer(&udev
->timeout
); /* no more pending cmds */
589 spin_unlock_irqrestore(&udev
->cmdr_lock
, flags
);
591 wake_up(&udev
->wait_cmdr
);
596 static int tcmu_check_expired_cmd(int id
, void *p
, void *data
)
598 struct tcmu_cmd
*cmd
= p
;
600 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
))
603 if (!time_after(cmd
->deadline
, jiffies
))
606 set_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
);
607 target_complete_cmd(cmd
->se_cmd
, SAM_STAT_CHECK_CONDITION
);
610 kmem_cache_free(tcmu_cmd_cache
, cmd
);
615 static void tcmu_device_timedout(unsigned long data
)
617 struct tcmu_dev
*udev
= (struct tcmu_dev
*)data
;
621 handled
= tcmu_handle_completions(udev
);
623 pr_warn("%d completions handled from timeout\n", handled
);
625 spin_lock_irqsave(&udev
->commands_lock
, flags
);
626 idr_for_each(&udev
->commands
, tcmu_check_expired_cmd
, NULL
);
627 spin_unlock_irqrestore(&udev
->commands_lock
, flags
);
630 * We don't need to wakeup threads on wait_cmdr since they have their
635 static int tcmu_attach_hba(struct se_hba
*hba
, u32 host_id
)
637 struct tcmu_hba
*tcmu_hba
;
639 tcmu_hba
= kzalloc(sizeof(struct tcmu_hba
), GFP_KERNEL
);
643 tcmu_hba
->host_id
= host_id
;
644 hba
->hba_ptr
= tcmu_hba
;
649 static void tcmu_detach_hba(struct se_hba
*hba
)
655 static struct se_device
*tcmu_alloc_device(struct se_hba
*hba
, const char *name
)
657 struct tcmu_dev
*udev
;
659 udev
= kzalloc(sizeof(struct tcmu_dev
), GFP_KERNEL
);
663 udev
->name
= kstrdup(name
, GFP_KERNEL
);
671 init_waitqueue_head(&udev
->wait_cmdr
);
672 spin_lock_init(&udev
->cmdr_lock
);
674 idr_init(&udev
->commands
);
675 spin_lock_init(&udev
->commands_lock
);
677 setup_timer(&udev
->timeout
, tcmu_device_timedout
,
678 (unsigned long)udev
);
680 return &udev
->se_dev
;
683 static int tcmu_irqcontrol(struct uio_info
*info
, s32 irq_on
)
685 struct tcmu_dev
*tcmu_dev
= container_of(info
, struct tcmu_dev
, uio_info
);
687 tcmu_handle_completions(tcmu_dev
);
693 * mmap code from uio.c. Copied here because we want to hook mmap()
694 * and this stuff must come along.
696 static int tcmu_find_mem_index(struct vm_area_struct
*vma
)
698 struct tcmu_dev
*udev
= vma
->vm_private_data
;
699 struct uio_info
*info
= &udev
->uio_info
;
701 if (vma
->vm_pgoff
< MAX_UIO_MAPS
) {
702 if (info
->mem
[vma
->vm_pgoff
].size
== 0)
704 return (int)vma
->vm_pgoff
;
709 static int tcmu_vma_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
711 struct tcmu_dev
*udev
= vma
->vm_private_data
;
712 struct uio_info
*info
= &udev
->uio_info
;
714 unsigned long offset
;
717 int mi
= tcmu_find_mem_index(vma
);
719 return VM_FAULT_SIGBUS
;
722 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
725 offset
= (vmf
->pgoff
- mi
) << PAGE_SHIFT
;
727 addr
= (void *)(unsigned long)info
->mem
[mi
].addr
+ offset
;
728 if (info
->mem
[mi
].memtype
== UIO_MEM_LOGICAL
)
729 page
= virt_to_page(addr
);
731 page
= vmalloc_to_page(addr
);
737 static const struct vm_operations_struct tcmu_vm_ops
= {
738 .fault
= tcmu_vma_fault
,
741 static int tcmu_mmap(struct uio_info
*info
, struct vm_area_struct
*vma
)
743 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
745 vma
->vm_flags
|= VM_DONTEXPAND
| VM_DONTDUMP
;
746 vma
->vm_ops
= &tcmu_vm_ops
;
748 vma
->vm_private_data
= udev
;
750 /* Ensure the mmap is exactly the right size */
751 if (vma_pages(vma
) != (TCMU_RING_SIZE
>> PAGE_SHIFT
))
757 static int tcmu_open(struct uio_info
*info
, struct inode
*inode
)
759 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
761 /* O_EXCL not supported for char devs, so fake it? */
762 if (test_and_set_bit(TCMU_DEV_BIT_OPEN
, &udev
->flags
))
770 static int tcmu_release(struct uio_info
*info
, struct inode
*inode
)
772 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
774 clear_bit(TCMU_DEV_BIT_OPEN
, &udev
->flags
);
781 static int tcmu_netlink_event(enum tcmu_genl_cmd cmd
, const char *name
, int minor
)
787 skb
= genlmsg_new(NLMSG_GOODSIZE
, GFP_KERNEL
);
791 msg_header
= genlmsg_put(skb
, 0, 0, &tcmu_genl_family
, 0, cmd
);
795 ret
= nla_put_string(skb
, TCMU_ATTR_DEVICE
, name
);
799 ret
= nla_put_u32(skb
, TCMU_ATTR_MINOR
, minor
);
803 genlmsg_end(skb
, msg_header
);
805 ret
= genlmsg_multicast(&tcmu_genl_family
, skb
, 0,
806 TCMU_MCGRP_CONFIG
, GFP_KERNEL
);
808 /* We don't care if no one is listening */
818 static int tcmu_configure_device(struct se_device
*dev
)
820 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
821 struct tcmu_hba
*hba
= udev
->hba
->hba_ptr
;
822 struct uio_info
*info
;
823 struct tcmu_mailbox
*mb
;
829 info
= &udev
->uio_info
;
831 size
= snprintf(NULL
, 0, "tcm-user/%u/%s/%s", hba
->host_id
, udev
->name
,
833 size
+= 1; /* for \0 */
834 str
= kmalloc(size
, GFP_KERNEL
);
838 used
= snprintf(str
, size
, "tcm-user/%u/%s", hba
->host_id
, udev
->name
);
840 if (udev
->dev_config
[0])
841 snprintf(str
+ used
, size
- used
, "/%s", udev
->dev_config
);
845 udev
->mb_addr
= vzalloc(TCMU_RING_SIZE
);
846 if (!udev
->mb_addr
) {
851 /* mailbox fits in first part of CMDR space */
852 udev
->cmdr_size
= CMDR_SIZE
- CMDR_OFF
;
853 udev
->data_off
= CMDR_SIZE
;
854 udev
->data_size
= TCMU_RING_SIZE
- CMDR_SIZE
;
857 mb
->version
= TCMU_MAILBOX_VERSION
;
858 mb
->cmdr_off
= CMDR_OFF
;
859 mb
->cmdr_size
= udev
->cmdr_size
;
861 WARN_ON(!PAGE_ALIGNED(udev
->data_off
));
862 WARN_ON(udev
->data_size
% PAGE_SIZE
);
864 info
->version
= xstr(TCMU_MAILBOX_VERSION
);
866 info
->mem
[0].name
= "tcm-user command & data buffer";
867 info
->mem
[0].addr
= (phys_addr_t
) udev
->mb_addr
;
868 info
->mem
[0].size
= TCMU_RING_SIZE
;
869 info
->mem
[0].memtype
= UIO_MEM_VIRTUAL
;
871 info
->irqcontrol
= tcmu_irqcontrol
;
872 info
->irq
= UIO_IRQ_CUSTOM
;
874 info
->mmap
= tcmu_mmap
;
875 info
->open
= tcmu_open
;
876 info
->release
= tcmu_release
;
878 ret
= uio_register_device(tcmu_root_device
, info
);
882 /* Other attributes can be configured in userspace */
883 dev
->dev_attrib
.hw_block_size
= 512;
884 dev
->dev_attrib
.hw_max_sectors
= 128;
885 dev
->dev_attrib
.hw_queue_depth
= 128;
887 ret
= tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE
, udev
->uio_info
.name
,
888 udev
->uio_info
.uio_dev
->minor
);
895 uio_unregister_device(&udev
->uio_info
);
897 vfree(udev
->mb_addr
);
904 static int tcmu_check_pending_cmd(int id
, void *p
, void *data
)
906 struct tcmu_cmd
*cmd
= p
;
908 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
))
913 static void tcmu_free_device(struct se_device
*dev
)
915 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
918 del_timer_sync(&udev
->timeout
);
920 vfree(udev
->mb_addr
);
922 /* Upper layer should drain all requests before calling this */
923 spin_lock_irq(&udev
->commands_lock
);
924 i
= idr_for_each(&udev
->commands
, tcmu_check_pending_cmd
, NULL
);
925 idr_destroy(&udev
->commands
);
926 spin_unlock_irq(&udev
->commands_lock
);
929 /* Device was configured */
930 if (udev
->uio_info
.uio_dev
) {
931 tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE
, udev
->uio_info
.name
,
932 udev
->uio_info
.uio_dev
->minor
);
934 uio_unregister_device(&udev
->uio_info
);
935 kfree(udev
->uio_info
.name
);
943 Opt_dev_config
, Opt_dev_size
, Opt_hw_block_size
, Opt_err
,
946 static match_table_t tokens
= {
947 {Opt_dev_config
, "dev_config=%s"},
948 {Opt_dev_size
, "dev_size=%u"},
949 {Opt_hw_block_size
, "hw_block_size=%u"},
953 static ssize_t
tcmu_set_configfs_dev_params(struct se_device
*dev
,
954 const char *page
, ssize_t count
)
956 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
957 char *orig
, *ptr
, *opts
, *arg_p
;
958 substring_t args
[MAX_OPT_ARGS
];
960 unsigned long tmp_ul
;
962 opts
= kstrdup(page
, GFP_KERNEL
);
968 while ((ptr
= strsep(&opts
, ",\n")) != NULL
) {
972 token
= match_token(ptr
, tokens
, args
);
975 if (match_strlcpy(udev
->dev_config
, &args
[0],
976 TCMU_CONFIG_LEN
) == 0) {
980 pr_debug("TCMU: Referencing Path: %s\n", udev
->dev_config
);
983 arg_p
= match_strdup(&args
[0]);
988 ret
= kstrtoul(arg_p
, 0, (unsigned long *) &udev
->dev_size
);
991 pr_err("kstrtoul() failed for dev_size=\n");
993 case Opt_hw_block_size
:
994 arg_p
= match_strdup(&args
[0]);
999 ret
= kstrtoul(arg_p
, 0, &tmp_ul
);
1002 pr_err("kstrtoul() failed for hw_block_size=\n");
1006 pr_err("hw_block_size must be nonzero\n");
1009 dev
->dev_attrib
.hw_block_size
= tmp_ul
;
1017 return (!ret
) ? count
: ret
;
1020 static ssize_t
tcmu_show_configfs_dev_params(struct se_device
*dev
, char *b
)
1022 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1025 bl
= sprintf(b
+ bl
, "Config: %s ",
1026 udev
->dev_config
[0] ? udev
->dev_config
: "NULL");
1027 bl
+= sprintf(b
+ bl
, "Size: %zu\n", udev
->dev_size
);
1032 static sector_t
tcmu_get_blocks(struct se_device
*dev
)
1034 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1036 return div_u64(udev
->dev_size
- dev
->dev_attrib
.block_size
,
1037 dev
->dev_attrib
.block_size
);
1040 static sense_reason_t
1041 tcmu_pass_op(struct se_cmd
*se_cmd
)
1043 int ret
= tcmu_queue_cmd(se_cmd
);
1046 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
1048 return TCM_NO_SENSE
;
1051 static sense_reason_t
1052 tcmu_parse_cdb(struct se_cmd
*cmd
)
1054 return passthrough_parse_cdb(cmd
, tcmu_pass_op
);
1057 DEF_TB_DEV_ATTRIB_RO(tcmu
, hw_pi_prot_type
);
1058 TB_DEV_ATTR_RO(tcmu
, hw_pi_prot_type
);
1060 DEF_TB_DEV_ATTRIB_RO(tcmu
, hw_block_size
);
1061 TB_DEV_ATTR_RO(tcmu
, hw_block_size
);
1063 DEF_TB_DEV_ATTRIB_RO(tcmu
, hw_max_sectors
);
1064 TB_DEV_ATTR_RO(tcmu
, hw_max_sectors
);
1066 DEF_TB_DEV_ATTRIB_RO(tcmu
, hw_queue_depth
);
1067 TB_DEV_ATTR_RO(tcmu
, hw_queue_depth
);
1069 static struct configfs_attribute
*tcmu_backend_dev_attrs
[] = {
1070 &tcmu_dev_attrib_hw_pi_prot_type
.attr
,
1071 &tcmu_dev_attrib_hw_block_size
.attr
,
1072 &tcmu_dev_attrib_hw_max_sectors
.attr
,
1073 &tcmu_dev_attrib_hw_queue_depth
.attr
,
1077 static struct se_subsystem_api tcmu_template
= {
1079 .inquiry_prod
= "USER",
1080 .inquiry_rev
= TCMU_VERSION
,
1081 .owner
= THIS_MODULE
,
1082 .transport_flags
= TRANSPORT_FLAG_PASSTHROUGH
,
1083 .attach_hba
= tcmu_attach_hba
,
1084 .detach_hba
= tcmu_detach_hba
,
1085 .alloc_device
= tcmu_alloc_device
,
1086 .configure_device
= tcmu_configure_device
,
1087 .free_device
= tcmu_free_device
,
1088 .parse_cdb
= tcmu_parse_cdb
,
1089 .set_configfs_dev_params
= tcmu_set_configfs_dev_params
,
1090 .show_configfs_dev_params
= tcmu_show_configfs_dev_params
,
1091 .get_device_type
= sbc_get_device_type
,
1092 .get_blocks
= tcmu_get_blocks
,
1095 static int __init
tcmu_module_init(void)
1097 struct target_backend_cits
*tbc
= &tcmu_template
.tb_cits
;
1100 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry
) % TCMU_OP_ALIGN_SIZE
) != 0);
1102 tcmu_cmd_cache
= kmem_cache_create("tcmu_cmd_cache",
1103 sizeof(struct tcmu_cmd
),
1104 __alignof__(struct tcmu_cmd
),
1106 if (!tcmu_cmd_cache
)
1109 tcmu_root_device
= root_device_register("tcm_user");
1110 if (IS_ERR(tcmu_root_device
)) {
1111 ret
= PTR_ERR(tcmu_root_device
);
1112 goto out_free_cache
;
1115 ret
= genl_register_family(&tcmu_genl_family
);
1117 goto out_unreg_device
;
1120 target_core_setup_sub_cits(&tcmu_template
);
1121 tbc
->tb_dev_attrib_cit
.ct_attrs
= tcmu_backend_dev_attrs
;
1123 ret
= transport_subsystem_register(&tcmu_template
);
1125 goto out_unreg_genl
;
1130 genl_unregister_family(&tcmu_genl_family
);
1132 root_device_unregister(tcmu_root_device
);
1134 kmem_cache_destroy(tcmu_cmd_cache
);
1139 static void __exit
tcmu_module_exit(void)
1141 transport_subsystem_release(&tcmu_template
);
1142 genl_unregister_family(&tcmu_genl_family
);
1143 root_device_unregister(tcmu_root_device
);
1144 kmem_cache_destroy(tcmu_cmd_cache
);
1147 MODULE_DESCRIPTION("TCM USER subsystem plugin");
1148 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
1149 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
1150 MODULE_LICENSE("GPL");
1152 module_init(tcmu_module_init
);
1153 module_exit(tcmu_module_exit
);