2 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
3 * Copyright (C) 2014 Red Hat, Inc.
4 * Copyright (C) 2015 Arrikto, Inc.
5 * Copyright (C) 2017 Chinamobile, Inc.
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
21 #include <linux/spinlock.h>
22 #include <linux/module.h>
23 #include <linux/idr.h>
24 #include <linux/kernel.h>
25 #include <linux/timer.h>
26 #include <linux/parser.h>
27 #include <linux/vmalloc.h>
28 #include <linux/uio_driver.h>
29 #include <linux/radix-tree.h>
30 #include <linux/stringify.h>
31 #include <linux/bitops.h>
32 #include <linux/highmem.h>
33 #include <linux/configfs.h>
34 #include <linux/mutex.h>
35 #include <linux/kthread.h>
36 #include <net/genetlink.h>
37 #include <scsi/scsi_common.h>
38 #include <scsi/scsi_proto.h>
39 #include <target/target_core_base.h>
40 #include <target/target_core_fabric.h>
41 #include <target/target_core_backend.h>
43 #include <linux/target_core_user.h>
46 * Define a shared-memory interface for LIO to pass SCSI commands and
47 * data to userspace for processing. This is to allow backends that
48 * are too complex for in-kernel support to be possible.
50 * It uses the UIO framework to do a lot of the device-creation and
51 * introspection work for us.
53 * See the .h file for how the ring is laid out. Note that while the
54 * command ring is defined, the particulars of the data area are
55 * not. Offset values in the command entry point to other locations
56 * internal to the mmap()ed area. There is separate space outside the
57 * command ring for data buffers. This leaves maximum flexibility for
58 * moving buffer allocations, or even page flipping or other
59 * allocation techniques, without altering the command ring layout.
62 * The user process must be assumed to be malicious. There's no way to
63 * prevent it breaking the command ring protocol if it wants, but in
64 * order to prevent other issues we must only ever read *data* from
65 * the shared memory area, not offsets or sizes. This applies to
66 * command ring entries as well as the mailbox. Extra code needed for
67 * this may have a 'UAM' comment.
70 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
72 /* For cmd area, the size is fixed 8MB */
73 #define CMDR_SIZE (8 * 1024 * 1024)
76 * For data area, the block size is PAGE_SIZE and
77 * the total size is 256K * PAGE_SIZE.
79 #define DATA_BLOCK_SIZE PAGE_SIZE
80 #define DATA_BLOCK_BITS (256 * 1024)
81 #define DATA_SIZE (DATA_BLOCK_BITS * DATA_BLOCK_SIZE)
82 #define DATA_BLOCK_INIT_BITS 128
84 /* The total size of the ring is 8M + 256K * PAGE_SIZE */
85 #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
87 /* Default maximum of the global data blocks(512K * PAGE_SIZE) */
88 #define TCMU_GLOBAL_MAX_BLOCKS (512 * 1024)
90 static struct device
*tcmu_root_device
;
96 #define TCMU_CONFIG_LEN 256
99 struct list_head node
;
101 struct se_device se_dev
;
106 #define TCMU_DEV_BIT_OPEN 0
107 #define TCMU_DEV_BIT_BROKEN 1
110 struct uio_info uio_info
;
114 struct tcmu_mailbox
*mb_addr
;
117 u32 cmdr_last_cleaned
;
118 /* Offset of data area from start of mb */
119 /* Must add data_off and mb_addr to get the address */
123 wait_queue_head_t wait_cmdr
;
124 struct mutex cmdr_lock
;
129 DECLARE_BITMAP(data_bitmap
, DATA_BLOCK_BITS
);
130 struct radix_tree_root data_blocks
;
133 spinlock_t commands_lock
;
135 struct timer_list timeout
;
136 unsigned int cmd_time_out
;
138 char dev_config
[TCMU_CONFIG_LEN
];
141 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
143 #define CMDR_OFF sizeof(struct tcmu_mailbox)
146 struct se_cmd
*se_cmd
;
147 struct tcmu_dev
*tcmu_dev
;
151 /* Can't use se_cmd when cleaning up expired cmds, because if
152 cmd has been completed then accessing se_cmd is off limits */
157 unsigned long deadline
;
159 #define TCMU_CMD_BIT_EXPIRED 0
163 static struct task_struct
*unmap_thread
;
164 static wait_queue_head_t unmap_wait
;
165 static DEFINE_MUTEX(root_udev_mutex
);
166 static LIST_HEAD(root_udev
);
168 static atomic_t global_db_count
= ATOMIC_INIT(0);
170 static struct kmem_cache
*tcmu_cmd_cache
;
172 /* multicast group */
173 enum tcmu_multicast_groups
{
177 static const struct genl_multicast_group tcmu_mcgrps
[] = {
178 [TCMU_MCGRP_CONFIG
] = { .name
= "config", },
181 /* Our generic netlink family */
182 static struct genl_family tcmu_genl_family __ro_after_init
= {
183 .module
= THIS_MODULE
,
187 .maxattr
= TCMU_ATTR_MAX
,
188 .mcgrps
= tcmu_mcgrps
,
189 .n_mcgrps
= ARRAY_SIZE(tcmu_mcgrps
),
193 #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
194 #define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
195 #define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
196 #define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
198 static void tcmu_cmd_free_data(struct tcmu_cmd
*tcmu_cmd
, uint32_t len
)
200 struct tcmu_dev
*udev
= tcmu_cmd
->tcmu_dev
;
203 for (i
= 0; i
< len
; i
++)
204 clear_bit(tcmu_cmd
->dbi
[i
], udev
->data_bitmap
);
207 static inline bool tcmu_get_empty_block(struct tcmu_dev
*udev
,
208 struct tcmu_cmd
*tcmu_cmd
)
213 dbi
= find_first_zero_bit(udev
->data_bitmap
, udev
->dbi_thresh
);
214 if (dbi
== udev
->dbi_thresh
)
217 page
= radix_tree_lookup(&udev
->data_blocks
, dbi
);
220 if (atomic_add_return(1, &global_db_count
) >
221 TCMU_GLOBAL_MAX_BLOCKS
) {
222 atomic_dec(&global_db_count
);
226 /* try to get new page from the mm */
227 page
= alloc_page(GFP_KERNEL
);
231 ret
= radix_tree_insert(&udev
->data_blocks
, dbi
, page
);
239 if (dbi
> udev
->dbi_max
)
242 set_bit(dbi
, udev
->data_bitmap
);
243 tcmu_cmd_set_dbi(tcmu_cmd
, dbi
);
248 static bool tcmu_get_empty_blocks(struct tcmu_dev
*udev
,
249 struct tcmu_cmd
*tcmu_cmd
)
253 udev
->waiting_global
= false;
255 for (i
= tcmu_cmd
->dbi_cur
; i
< tcmu_cmd
->dbi_cnt
; i
++) {
256 if (!tcmu_get_empty_block(udev
, tcmu_cmd
))
262 udev
->waiting_global
= true;
263 /* Try to wake up the unmap thread */
264 wake_up(&unmap_wait
);
268 static inline struct page
*
269 tcmu_get_block_page(struct tcmu_dev
*udev
, uint32_t dbi
)
271 return radix_tree_lookup(&udev
->data_blocks
, dbi
);
274 static inline void tcmu_free_cmd(struct tcmu_cmd
*tcmu_cmd
)
276 kfree(tcmu_cmd
->dbi
);
277 kmem_cache_free(tcmu_cmd_cache
, tcmu_cmd
);
280 static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd
*tcmu_cmd
)
282 struct se_cmd
*se_cmd
= tcmu_cmd
->se_cmd
;
283 size_t data_length
= round_up(se_cmd
->data_length
, DATA_BLOCK_SIZE
);
285 if (se_cmd
->se_cmd_flags
& SCF_BIDI
) {
286 BUG_ON(!(se_cmd
->t_bidi_data_sg
&& se_cmd
->t_bidi_data_nents
));
287 data_length
+= round_up(se_cmd
->t_bidi_data_sg
->length
,
294 static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd
*tcmu_cmd
)
296 size_t data_length
= tcmu_cmd_get_data_length(tcmu_cmd
);
298 return data_length
/ DATA_BLOCK_SIZE
;
301 static struct tcmu_cmd
*tcmu_alloc_cmd(struct se_cmd
*se_cmd
)
303 struct se_device
*se_dev
= se_cmd
->se_dev
;
304 struct tcmu_dev
*udev
= TCMU_DEV(se_dev
);
305 struct tcmu_cmd
*tcmu_cmd
;
308 tcmu_cmd
= kmem_cache_zalloc(tcmu_cmd_cache
, GFP_KERNEL
);
312 tcmu_cmd
->se_cmd
= se_cmd
;
313 tcmu_cmd
->tcmu_dev
= udev
;
314 if (udev
->cmd_time_out
)
315 tcmu_cmd
->deadline
= jiffies
+
316 msecs_to_jiffies(udev
->cmd_time_out
);
318 tcmu_cmd_reset_dbi_cur(tcmu_cmd
);
319 tcmu_cmd
->dbi_cnt
= tcmu_cmd_get_block_cnt(tcmu_cmd
);
320 tcmu_cmd
->dbi
= kcalloc(tcmu_cmd
->dbi_cnt
, sizeof(uint32_t),
322 if (!tcmu_cmd
->dbi
) {
323 kmem_cache_free(tcmu_cmd_cache
, tcmu_cmd
);
327 idr_preload(GFP_KERNEL
);
328 spin_lock_irq(&udev
->commands_lock
);
329 cmd_id
= idr_alloc(&udev
->commands
, tcmu_cmd
, 0,
330 USHRT_MAX
, GFP_NOWAIT
);
331 spin_unlock_irq(&udev
->commands_lock
);
335 tcmu_free_cmd(tcmu_cmd
);
338 tcmu_cmd
->cmd_id
= cmd_id
;
343 static inline void tcmu_flush_dcache_range(void *vaddr
, size_t size
)
345 unsigned long offset
= offset_in_page(vaddr
);
347 size
= round_up(size
+offset
, PAGE_SIZE
);
351 flush_dcache_page(virt_to_page(vaddr
));
357 * Some ring helper functions. We don't assume size is a power of 2 so
358 * we can't use circ_buf.h.
360 static inline size_t spc_used(size_t head
, size_t tail
, size_t size
)
362 int diff
= head
- tail
;
370 static inline size_t spc_free(size_t head
, size_t tail
, size_t size
)
372 /* Keep 1 byte unused or we can't tell full from empty */
373 return (size
- spc_used(head
, tail
, size
) - 1);
376 static inline size_t head_to_end(size_t head
, size_t size
)
381 static inline void new_iov(struct iovec
**iov
, int *iov_cnt
,
382 struct tcmu_dev
*udev
)
391 memset(iovec
, 0, sizeof(struct iovec
));
394 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
396 /* offset is relative to mb_addr */
397 static inline size_t get_block_offset_user(struct tcmu_dev
*dev
,
398 int dbi
, int remaining
)
400 return dev
->data_off
+ dbi
* DATA_BLOCK_SIZE
+
401 DATA_BLOCK_SIZE
- remaining
;
404 static inline size_t iov_tail(struct tcmu_dev
*udev
, struct iovec
*iov
)
406 return (size_t)iov
->iov_base
+ iov
->iov_len
;
409 static int scatter_data_area(struct tcmu_dev
*udev
,
410 struct tcmu_cmd
*tcmu_cmd
, struct scatterlist
*data_sg
,
411 unsigned int data_nents
, struct iovec
**iov
,
412 int *iov_cnt
, bool copy_data
)
415 int block_remaining
= 0;
416 void *from
, *to
= NULL
;
417 size_t copy_bytes
, to_offset
, offset
;
418 struct scatterlist
*sg
;
421 for_each_sg(data_sg
, sg
, data_nents
, i
) {
422 int sg_remaining
= sg
->length
;
423 from
= kmap_atomic(sg_page(sg
)) + sg
->offset
;
424 while (sg_remaining
> 0) {
425 if (block_remaining
== 0) {
429 block_remaining
= DATA_BLOCK_SIZE
;
430 dbi
= tcmu_cmd_get_dbi(tcmu_cmd
);
431 page
= tcmu_get_block_page(udev
, dbi
);
432 to
= kmap_atomic(page
);
435 copy_bytes
= min_t(size_t, sg_remaining
,
437 to_offset
= get_block_offset_user(udev
, dbi
,
439 offset
= DATA_BLOCK_SIZE
- block_remaining
;
440 to
= (void *)(unsigned long)to
+ offset
;
443 to_offset
== iov_tail(udev
, *iov
)) {
444 (*iov
)->iov_len
+= copy_bytes
;
446 new_iov(iov
, iov_cnt
, udev
);
447 (*iov
)->iov_base
= (void __user
*)to_offset
;
448 (*iov
)->iov_len
= copy_bytes
;
451 memcpy(to
, from
+ sg
->length
- sg_remaining
,
453 tcmu_flush_dcache_range(to
, copy_bytes
);
455 sg_remaining
-= copy_bytes
;
456 block_remaining
-= copy_bytes
;
458 kunmap_atomic(from
- sg
->offset
);
466 static void gather_data_area(struct tcmu_dev
*udev
, struct tcmu_cmd
*cmd
,
469 struct se_cmd
*se_cmd
= cmd
->se_cmd
;
471 int block_remaining
= 0;
472 void *from
= NULL
, *to
;
473 size_t copy_bytes
, offset
;
474 struct scatterlist
*sg
, *data_sg
;
476 unsigned int data_nents
;
480 data_sg
= se_cmd
->t_data_sg
;
481 data_nents
= se_cmd
->t_data_nents
;
485 * For bidi case, the first count blocks are for Data-Out
486 * buffer blocks, and before gathering the Data-In buffer
487 * the Data-Out buffer blocks should be discarded.
489 count
= DIV_ROUND_UP(se_cmd
->data_length
, DATA_BLOCK_SIZE
);
491 data_sg
= se_cmd
->t_bidi_data_sg
;
492 data_nents
= se_cmd
->t_bidi_data_nents
;
495 tcmu_cmd_set_dbi_cur(cmd
, count
);
497 for_each_sg(data_sg
, sg
, data_nents
, i
) {
498 int sg_remaining
= sg
->length
;
499 to
= kmap_atomic(sg_page(sg
)) + sg
->offset
;
500 while (sg_remaining
> 0) {
501 if (block_remaining
== 0) {
505 block_remaining
= DATA_BLOCK_SIZE
;
506 dbi
= tcmu_cmd_get_dbi(cmd
);
507 page
= tcmu_get_block_page(udev
, dbi
);
508 from
= kmap_atomic(page
);
510 copy_bytes
= min_t(size_t, sg_remaining
,
512 offset
= DATA_BLOCK_SIZE
- block_remaining
;
513 from
= (void *)(unsigned long)from
+ offset
;
514 tcmu_flush_dcache_range(from
, copy_bytes
);
515 memcpy(to
+ sg
->length
- sg_remaining
, from
,
518 sg_remaining
-= copy_bytes
;
519 block_remaining
-= copy_bytes
;
521 kunmap_atomic(to
- sg
->offset
);
527 static inline size_t spc_bitmap_free(unsigned long *bitmap
, uint32_t thresh
)
529 return DATA_BLOCK_SIZE
* (thresh
- bitmap_weight(bitmap
, thresh
));
533 * We can't queue a command until we have space available on the cmd ring *and*
534 * space available on the data area.
536 * Called with ring lock held.
538 static bool is_ring_space_avail(struct tcmu_dev
*udev
, struct tcmu_cmd
*cmd
,
539 size_t cmd_size
, size_t data_needed
)
541 struct tcmu_mailbox
*mb
= udev
->mb_addr
;
542 uint32_t blocks_needed
= (data_needed
+ DATA_BLOCK_SIZE
- 1)
544 size_t space
, cmd_needed
;
547 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
549 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
552 * If cmd end-of-ring space is too small then we need space for a NOP plus
553 * original cmd - cmds are internally contiguous.
555 if (head_to_end(cmd_head
, udev
->cmdr_size
) >= cmd_size
)
556 cmd_needed
= cmd_size
;
558 cmd_needed
= cmd_size
+ head_to_end(cmd_head
, udev
->cmdr_size
);
560 space
= spc_free(cmd_head
, udev
->cmdr_last_cleaned
, udev
->cmdr_size
);
561 if (space
< cmd_needed
) {
562 pr_debug("no cmd space: %u %u %u\n", cmd_head
,
563 udev
->cmdr_last_cleaned
, udev
->cmdr_size
);
567 /* try to check and get the data blocks as needed */
568 space
= spc_bitmap_free(udev
->data_bitmap
, udev
->dbi_thresh
);
569 if (space
< data_needed
) {
570 unsigned long blocks_left
= DATA_BLOCK_BITS
- udev
->dbi_thresh
;
573 if (blocks_left
< blocks_needed
) {
574 pr_debug("no data space: only %lu available, but ask for %zu\n",
575 blocks_left
* DATA_BLOCK_SIZE
,
580 /* Try to expand the thresh */
581 if (!udev
->dbi_thresh
) {
582 /* From idle state */
583 uint32_t init_thresh
= DATA_BLOCK_INIT_BITS
;
585 udev
->dbi_thresh
= max(blocks_needed
, init_thresh
);
588 * Grow the data area by max(blocks needed,
589 * dbi_thresh / 2), but limited to the max
590 * DATA_BLOCK_BITS size.
592 grow
= max(blocks_needed
, udev
->dbi_thresh
/ 2);
593 udev
->dbi_thresh
+= grow
;
594 if (udev
->dbi_thresh
> DATA_BLOCK_BITS
)
595 udev
->dbi_thresh
= DATA_BLOCK_BITS
;
599 if (!tcmu_get_empty_blocks(udev
, cmd
))
605 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt
)
607 return max(offsetof(struct tcmu_cmd_entry
, req
.iov
[iov_cnt
]),
608 sizeof(struct tcmu_cmd_entry
));
611 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd
*tcmu_cmd
,
612 size_t base_command_size
)
614 struct se_cmd
*se_cmd
= tcmu_cmd
->se_cmd
;
617 command_size
= base_command_size
+
618 round_up(scsi_command_size(se_cmd
->t_task_cdb
),
621 WARN_ON(command_size
& (TCMU_OP_ALIGN_SIZE
-1));
626 static sense_reason_t
627 tcmu_queue_cmd_ring(struct tcmu_cmd
*tcmu_cmd
)
629 struct tcmu_dev
*udev
= tcmu_cmd
->tcmu_dev
;
630 struct se_cmd
*se_cmd
= tcmu_cmd
->se_cmd
;
631 size_t base_command_size
, command_size
;
632 struct tcmu_mailbox
*mb
;
633 struct tcmu_cmd_entry
*entry
;
638 bool copy_to_data_area
;
639 size_t data_length
= tcmu_cmd_get_data_length(tcmu_cmd
);
641 if (test_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
))
642 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
645 * Must be a certain minimum size for response sense info, but
646 * also may be larger if the iov array is large.
648 * We prepare as many iovs as possbile for potential uses here,
649 * because it's expensive to tell how many regions are freed in
650 * the bitmap & global data pool, as the size calculated here
651 * will only be used to do the checks.
653 * The size will be recalculated later as actually needed to save
656 base_command_size
= tcmu_cmd_get_base_cmd_size(tcmu_cmd
->dbi_cnt
);
657 command_size
= tcmu_cmd_get_cmd_size(tcmu_cmd
, base_command_size
);
659 mutex_lock(&udev
->cmdr_lock
);
662 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
663 if ((command_size
> (udev
->cmdr_size
/ 2)) ||
664 data_length
> udev
->data_size
) {
665 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
666 "cmd ring/data area\n", command_size
, data_length
,
667 udev
->cmdr_size
, udev
->data_size
);
668 mutex_unlock(&udev
->cmdr_lock
);
669 return TCM_INVALID_CDB_FIELD
;
672 while (!is_ring_space_avail(udev
, tcmu_cmd
, command_size
, data_length
)) {
676 prepare_to_wait(&udev
->wait_cmdr
, &__wait
, TASK_INTERRUPTIBLE
);
678 pr_debug("sleeping for ring space\n");
679 mutex_unlock(&udev
->cmdr_lock
);
680 if (udev
->cmd_time_out
)
681 ret
= schedule_timeout(
682 msecs_to_jiffies(udev
->cmd_time_out
));
684 ret
= schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT
));
685 finish_wait(&udev
->wait_cmdr
, &__wait
);
687 pr_warn("tcmu: command timed out\n");
688 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
691 mutex_lock(&udev
->cmdr_lock
);
693 /* We dropped cmdr_lock, cmd_head is stale */
694 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
697 /* Insert a PAD if end-of-ring space is too small */
698 if (head_to_end(cmd_head
, udev
->cmdr_size
) < command_size
) {
699 size_t pad_size
= head_to_end(cmd_head
, udev
->cmdr_size
);
701 entry
= (void *) mb
+ CMDR_OFF
+ cmd_head
;
702 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
703 tcmu_hdr_set_op(&entry
->hdr
.len_op
, TCMU_OP_PAD
);
704 tcmu_hdr_set_len(&entry
->hdr
.len_op
, pad_size
);
705 entry
->hdr
.cmd_id
= 0; /* not used for PAD */
706 entry
->hdr
.kflags
= 0;
707 entry
->hdr
.uflags
= 0;
709 UPDATE_HEAD(mb
->cmd_head
, pad_size
, udev
->cmdr_size
);
711 cmd_head
= mb
->cmd_head
% udev
->cmdr_size
; /* UAM */
712 WARN_ON(cmd_head
!= 0);
715 entry
= (void *) mb
+ CMDR_OFF
+ cmd_head
;
716 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
717 tcmu_hdr_set_op(&entry
->hdr
.len_op
, TCMU_OP_CMD
);
718 entry
->hdr
.cmd_id
= tcmu_cmd
->cmd_id
;
719 entry
->hdr
.kflags
= 0;
720 entry
->hdr
.uflags
= 0;
722 /* Handle allocating space from the data area */
723 tcmu_cmd_reset_dbi_cur(tcmu_cmd
);
724 iov
= &entry
->req
.iov
[0];
726 copy_to_data_area
= (se_cmd
->data_direction
== DMA_TO_DEVICE
727 || se_cmd
->se_cmd_flags
& SCF_BIDI
);
728 ret
= scatter_data_area(udev
, tcmu_cmd
, se_cmd
->t_data_sg
,
729 se_cmd
->t_data_nents
, &iov
, &iov_cnt
,
732 tcmu_cmd_free_data(tcmu_cmd
, tcmu_cmd
->dbi_cnt
);
733 mutex_unlock(&udev
->cmdr_lock
);
735 pr_err("tcmu: alloc and scatter data failed\n");
736 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
738 entry
->req
.iov_cnt
= iov_cnt
;
739 entry
->req
.iov_dif_cnt
= 0;
741 /* Handle BIDI commands */
742 if (se_cmd
->se_cmd_flags
& SCF_BIDI
) {
745 ret
= scatter_data_area(udev
, tcmu_cmd
,
746 se_cmd
->t_bidi_data_sg
,
747 se_cmd
->t_bidi_data_nents
,
748 &iov
, &iov_cnt
, false);
750 tcmu_cmd_free_data(tcmu_cmd
, tcmu_cmd
->dbi_cnt
);
751 mutex_unlock(&udev
->cmdr_lock
);
753 pr_err("tcmu: alloc and scatter bidi data failed\n");
754 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
756 entry
->req
.iov_bidi_cnt
= iov_cnt
;
760 * Recalaulate the command's base size and size according
761 * to the actual needs
763 base_command_size
= tcmu_cmd_get_base_cmd_size(entry
->req
.iov_cnt
+
764 entry
->req
.iov_bidi_cnt
);
765 command_size
= tcmu_cmd_get_cmd_size(tcmu_cmd
, base_command_size
);
767 tcmu_hdr_set_len(&entry
->hdr
.len_op
, command_size
);
769 /* All offsets relative to mb_addr, not start of entry! */
770 cdb_off
= CMDR_OFF
+ cmd_head
+ base_command_size
;
771 memcpy((void *) mb
+ cdb_off
, se_cmd
->t_task_cdb
, scsi_command_size(se_cmd
->t_task_cdb
));
772 entry
->req
.cdb_off
= cdb_off
;
773 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
775 UPDATE_HEAD(mb
->cmd_head
, command_size
, udev
->cmdr_size
);
776 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
777 mutex_unlock(&udev
->cmdr_lock
);
779 /* TODO: only if FLUSH and FUA? */
780 uio_event_notify(&udev
->uio_info
);
782 if (udev
->cmd_time_out
)
783 mod_timer(&udev
->timeout
, round_jiffies_up(jiffies
+
784 msecs_to_jiffies(udev
->cmd_time_out
)));
789 static sense_reason_t
790 tcmu_queue_cmd(struct se_cmd
*se_cmd
)
792 struct se_device
*se_dev
= se_cmd
->se_dev
;
793 struct tcmu_dev
*udev
= TCMU_DEV(se_dev
);
794 struct tcmu_cmd
*tcmu_cmd
;
797 tcmu_cmd
= tcmu_alloc_cmd(se_cmd
);
799 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
801 ret
= tcmu_queue_cmd_ring(tcmu_cmd
);
802 if (ret
!= TCM_NO_SENSE
) {
803 pr_err("TCMU: Could not queue command\n");
804 spin_lock_irq(&udev
->commands_lock
);
805 idr_remove(&udev
->commands
, tcmu_cmd
->cmd_id
);
806 spin_unlock_irq(&udev
->commands_lock
);
808 tcmu_free_cmd(tcmu_cmd
);
814 static void tcmu_handle_completion(struct tcmu_cmd
*cmd
, struct tcmu_cmd_entry
*entry
)
816 struct se_cmd
*se_cmd
= cmd
->se_cmd
;
817 struct tcmu_dev
*udev
= cmd
->tcmu_dev
;
820 * cmd has been completed already from timeout, just reclaim
821 * data area space and free cmd
823 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
))
826 tcmu_cmd_reset_dbi_cur(cmd
);
828 if (entry
->hdr
.uflags
& TCMU_UFLAG_UNKNOWN_OP
) {
829 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
831 entry
->rsp
.scsi_status
= SAM_STAT_CHECK_CONDITION
;
832 } else if (entry
->rsp
.scsi_status
== SAM_STAT_CHECK_CONDITION
) {
833 memcpy(se_cmd
->sense_buffer
, entry
->rsp
.sense_buffer
,
834 se_cmd
->scsi_sense_length
);
835 } else if (se_cmd
->se_cmd_flags
& SCF_BIDI
) {
836 /* Get Data-In buffer before clean up */
837 gather_data_area(udev
, cmd
, true);
838 } else if (se_cmd
->data_direction
== DMA_FROM_DEVICE
) {
839 gather_data_area(udev
, cmd
, false);
840 } else if (se_cmd
->data_direction
== DMA_TO_DEVICE
) {
842 } else if (se_cmd
->data_direction
!= DMA_NONE
) {
843 pr_warn("TCMU: data direction was %d!\n",
844 se_cmd
->data_direction
);
847 target_complete_cmd(cmd
->se_cmd
, entry
->rsp
.scsi_status
);
851 tcmu_cmd_free_data(cmd
, cmd
->dbi_cnt
);
855 static unsigned int tcmu_handle_completions(struct tcmu_dev
*udev
)
857 struct tcmu_mailbox
*mb
;
860 if (test_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
)) {
861 pr_err("ring broken, not handling completions\n");
866 tcmu_flush_dcache_range(mb
, sizeof(*mb
));
868 while (udev
->cmdr_last_cleaned
!= ACCESS_ONCE(mb
->cmd_tail
)) {
870 struct tcmu_cmd_entry
*entry
= (void *) mb
+ CMDR_OFF
+ udev
->cmdr_last_cleaned
;
871 struct tcmu_cmd
*cmd
;
873 tcmu_flush_dcache_range(entry
, sizeof(*entry
));
875 if (tcmu_hdr_get_op(entry
->hdr
.len_op
) == TCMU_OP_PAD
) {
876 UPDATE_HEAD(udev
->cmdr_last_cleaned
,
877 tcmu_hdr_get_len(entry
->hdr
.len_op
),
881 WARN_ON(tcmu_hdr_get_op(entry
->hdr
.len_op
) != TCMU_OP_CMD
);
883 spin_lock(&udev
->commands_lock
);
884 cmd
= idr_remove(&udev
->commands
, entry
->hdr
.cmd_id
);
885 spin_unlock(&udev
->commands_lock
);
888 pr_err("cmd_id not found, ring is broken\n");
889 set_bit(TCMU_DEV_BIT_BROKEN
, &udev
->flags
);
893 tcmu_handle_completion(cmd
, entry
);
895 UPDATE_HEAD(udev
->cmdr_last_cleaned
,
896 tcmu_hdr_get_len(entry
->hdr
.len_op
),
902 if (mb
->cmd_tail
== mb
->cmd_head
)
903 del_timer(&udev
->timeout
); /* no more pending cmds */
905 wake_up(&udev
->wait_cmdr
);
910 static int tcmu_check_expired_cmd(int id
, void *p
, void *data
)
912 struct tcmu_cmd
*cmd
= p
;
914 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
))
917 if (!time_after(jiffies
, cmd
->deadline
))
920 set_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
);
921 target_complete_cmd(cmd
->se_cmd
, SAM_STAT_CHECK_CONDITION
);
927 static void tcmu_device_timedout(unsigned long data
)
929 struct tcmu_dev
*udev
= (struct tcmu_dev
*)data
;
932 spin_lock_irqsave(&udev
->commands_lock
, flags
);
933 idr_for_each(&udev
->commands
, tcmu_check_expired_cmd
, NULL
);
934 spin_unlock_irqrestore(&udev
->commands_lock
, flags
);
936 /* Try to wake up the ummap thread */
937 wake_up(&unmap_wait
);
940 * We don't need to wakeup threads on wait_cmdr since they have their
945 static int tcmu_attach_hba(struct se_hba
*hba
, u32 host_id
)
947 struct tcmu_hba
*tcmu_hba
;
949 tcmu_hba
= kzalloc(sizeof(struct tcmu_hba
), GFP_KERNEL
);
953 tcmu_hba
->host_id
= host_id
;
954 hba
->hba_ptr
= tcmu_hba
;
959 static void tcmu_detach_hba(struct se_hba
*hba
)
965 static struct se_device
*tcmu_alloc_device(struct se_hba
*hba
, const char *name
)
967 struct tcmu_dev
*udev
;
969 udev
= kzalloc(sizeof(struct tcmu_dev
), GFP_KERNEL
);
972 kref_init(&udev
->kref
);
974 udev
->name
= kstrdup(name
, GFP_KERNEL
);
981 udev
->cmd_time_out
= TCMU_TIME_OUT
;
983 init_waitqueue_head(&udev
->wait_cmdr
);
984 mutex_init(&udev
->cmdr_lock
);
986 idr_init(&udev
->commands
);
987 spin_lock_init(&udev
->commands_lock
);
989 setup_timer(&udev
->timeout
, tcmu_device_timedout
,
990 (unsigned long)udev
);
992 return &udev
->se_dev
;
995 static int tcmu_irqcontrol(struct uio_info
*info
, s32 irq_on
)
997 struct tcmu_dev
*tcmu_dev
= container_of(info
, struct tcmu_dev
, uio_info
);
999 mutex_lock(&tcmu_dev
->cmdr_lock
);
1000 tcmu_handle_completions(tcmu_dev
);
1001 mutex_unlock(&tcmu_dev
->cmdr_lock
);
1007 * mmap code from uio.c. Copied here because we want to hook mmap()
1008 * and this stuff must come along.
1010 static int tcmu_find_mem_index(struct vm_area_struct
*vma
)
1012 struct tcmu_dev
*udev
= vma
->vm_private_data
;
1013 struct uio_info
*info
= &udev
->uio_info
;
1015 if (vma
->vm_pgoff
< MAX_UIO_MAPS
) {
1016 if (info
->mem
[vma
->vm_pgoff
].size
== 0)
1018 return (int)vma
->vm_pgoff
;
1023 static struct page
*tcmu_try_get_block_page(struct tcmu_dev
*udev
, uint32_t dbi
)
1028 mutex_lock(&udev
->cmdr_lock
);
1029 page
= tcmu_get_block_page(udev
, dbi
);
1031 mutex_unlock(&udev
->cmdr_lock
);
1036 * Normally it shouldn't be here:
1037 * Only when the userspace has touched the blocks which
1038 * are out of the tcmu_cmd's data iov[], and will return
1041 pr_warn("Block(%u) out of cmd's iov[] has been touched!\n", dbi
);
1042 pr_warn("Mostly it will be a bug of userspace, please have a check!\n");
1044 if (dbi
>= udev
->dbi_thresh
) {
1045 /* Extern the udev->dbi_thresh to dbi + 1 */
1046 udev
->dbi_thresh
= dbi
+ 1;
1047 udev
->dbi_max
= dbi
;
1050 page
= radix_tree_lookup(&udev
->data_blocks
, dbi
);
1052 page
= alloc_page(GFP_KERNEL
| __GFP_ZERO
);
1054 mutex_unlock(&udev
->cmdr_lock
);
1058 ret
= radix_tree_insert(&udev
->data_blocks
, dbi
, page
);
1060 mutex_unlock(&udev
->cmdr_lock
);
1066 * Since this case is rare in page fault routine, here we
1067 * will allow the global_db_count >= TCMU_GLOBAL_MAX_BLOCKS
1068 * to reduce possible page fault call trace.
1070 atomic_inc(&global_db_count
);
1072 mutex_unlock(&udev
->cmdr_lock
);
1077 static int tcmu_vma_fault(struct vm_fault
*vmf
)
1079 struct tcmu_dev
*udev
= vmf
->vma
->vm_private_data
;
1080 struct uio_info
*info
= &udev
->uio_info
;
1082 unsigned long offset
;
1085 int mi
= tcmu_find_mem_index(vmf
->vma
);
1087 return VM_FAULT_SIGBUS
;
1090 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1093 offset
= (vmf
->pgoff
- mi
) << PAGE_SHIFT
;
1095 if (offset
< udev
->data_off
) {
1096 /* For the vmalloc()ed cmd area pages */
1097 addr
= (void *)(unsigned long)info
->mem
[mi
].addr
+ offset
;
1098 page
= vmalloc_to_page(addr
);
1102 /* For the dynamically growing data area pages */
1103 dbi
= (offset
- udev
->data_off
) / DATA_BLOCK_SIZE
;
1104 page
= tcmu_try_get_block_page(udev
, dbi
);
1106 return VM_FAULT_NOPAGE
;
1114 static const struct vm_operations_struct tcmu_vm_ops
= {
1115 .fault
= tcmu_vma_fault
,
1118 static int tcmu_mmap(struct uio_info
*info
, struct vm_area_struct
*vma
)
1120 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
1122 vma
->vm_flags
|= VM_DONTEXPAND
| VM_DONTDUMP
;
1123 vma
->vm_ops
= &tcmu_vm_ops
;
1125 vma
->vm_private_data
= udev
;
1127 /* Ensure the mmap is exactly the right size */
1128 if (vma_pages(vma
) != (TCMU_RING_SIZE
>> PAGE_SHIFT
))
1134 static int tcmu_open(struct uio_info
*info
, struct inode
*inode
)
1136 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
1138 /* O_EXCL not supported for char devs, so fake it? */
1139 if (test_and_set_bit(TCMU_DEV_BIT_OPEN
, &udev
->flags
))
1142 udev
->inode
= inode
;
1149 static void tcmu_dev_call_rcu(struct rcu_head
*p
)
1151 struct se_device
*dev
= container_of(p
, struct se_device
, rcu_head
);
1152 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1154 kfree(udev
->uio_info
.name
);
1159 static void tcmu_dev_kref_release(struct kref
*kref
)
1161 struct tcmu_dev
*udev
= container_of(kref
, struct tcmu_dev
, kref
);
1162 struct se_device
*dev
= &udev
->se_dev
;
1164 call_rcu(&dev
->rcu_head
, tcmu_dev_call_rcu
);
1167 static int tcmu_release(struct uio_info
*info
, struct inode
*inode
)
1169 struct tcmu_dev
*udev
= container_of(info
, struct tcmu_dev
, uio_info
);
1171 clear_bit(TCMU_DEV_BIT_OPEN
, &udev
->flags
);
1173 pr_debug("close\n");
1174 /* release ref from configure */
1175 kref_put(&udev
->kref
, tcmu_dev_kref_release
);
1179 static int tcmu_netlink_event(enum tcmu_genl_cmd cmd
, const char *name
, int minor
)
1181 struct sk_buff
*skb
;
1185 skb
= genlmsg_new(NLMSG_GOODSIZE
, GFP_KERNEL
);
1189 msg_header
= genlmsg_put(skb
, 0, 0, &tcmu_genl_family
, 0, cmd
);
1193 ret
= nla_put_string(skb
, TCMU_ATTR_DEVICE
, name
);
1197 ret
= nla_put_u32(skb
, TCMU_ATTR_MINOR
, minor
);
1201 genlmsg_end(skb
, msg_header
);
1203 ret
= genlmsg_multicast_allns(&tcmu_genl_family
, skb
, 0,
1204 TCMU_MCGRP_CONFIG
, GFP_KERNEL
);
1206 /* We don't care if no one is listening */
1216 static int tcmu_configure_device(struct se_device
*dev
)
1218 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1219 struct tcmu_hba
*hba
= udev
->hba
->hba_ptr
;
1220 struct uio_info
*info
;
1221 struct tcmu_mailbox
*mb
;
1227 info
= &udev
->uio_info
;
1229 size
= snprintf(NULL
, 0, "tcm-user/%u/%s/%s", hba
->host_id
, udev
->name
,
1231 size
+= 1; /* for \0 */
1232 str
= kmalloc(size
, GFP_KERNEL
);
1236 used
= snprintf(str
, size
, "tcm-user/%u/%s", hba
->host_id
, udev
->name
);
1238 if (udev
->dev_config
[0])
1239 snprintf(str
+ used
, size
- used
, "/%s", udev
->dev_config
);
1243 udev
->mb_addr
= vzalloc(CMDR_SIZE
);
1244 if (!udev
->mb_addr
) {
1249 /* mailbox fits in first part of CMDR space */
1250 udev
->cmdr_size
= CMDR_SIZE
- CMDR_OFF
;
1251 udev
->data_off
= CMDR_SIZE
;
1252 udev
->data_size
= DATA_SIZE
;
1253 udev
->dbi_thresh
= 0; /* Default in Idle state */
1254 udev
->waiting_global
= false;
1256 /* Initialise the mailbox of the ring buffer */
1258 mb
->version
= TCMU_MAILBOX_VERSION
;
1259 mb
->flags
= TCMU_MAILBOX_FLAG_CAP_OOOC
;
1260 mb
->cmdr_off
= CMDR_OFF
;
1261 mb
->cmdr_size
= udev
->cmdr_size
;
1263 WARN_ON(!PAGE_ALIGNED(udev
->data_off
));
1264 WARN_ON(udev
->data_size
% PAGE_SIZE
);
1265 WARN_ON(udev
->data_size
% DATA_BLOCK_SIZE
);
1267 INIT_RADIX_TREE(&udev
->data_blocks
, GFP_KERNEL
);
1269 info
->version
= __stringify(TCMU_MAILBOX_VERSION
);
1271 info
->mem
[0].name
= "tcm-user command & data buffer";
1272 info
->mem
[0].addr
= (phys_addr_t
)(uintptr_t)udev
->mb_addr
;
1273 info
->mem
[0].size
= TCMU_RING_SIZE
;
1274 info
->mem
[0].memtype
= UIO_MEM_NONE
;
1276 info
->irqcontrol
= tcmu_irqcontrol
;
1277 info
->irq
= UIO_IRQ_CUSTOM
;
1279 info
->mmap
= tcmu_mmap
;
1280 info
->open
= tcmu_open
;
1281 info
->release
= tcmu_release
;
1283 ret
= uio_register_device(tcmu_root_device
, info
);
1287 /* User can set hw_block_size before enable the device */
1288 if (dev
->dev_attrib
.hw_block_size
== 0)
1289 dev
->dev_attrib
.hw_block_size
= 512;
1290 /* Other attributes can be configured in userspace */
1291 if (!dev
->dev_attrib
.hw_max_sectors
)
1292 dev
->dev_attrib
.hw_max_sectors
= 128;
1293 dev
->dev_attrib
.hw_queue_depth
= 128;
1296 * Get a ref incase userspace does a close on the uio device before
1297 * LIO has initiated tcmu_free_device.
1299 kref_get(&udev
->kref
);
1301 ret
= tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE
, udev
->uio_info
.name
,
1302 udev
->uio_info
.uio_dev
->minor
);
1306 mutex_lock(&root_udev_mutex
);
1307 list_add(&udev
->node
, &root_udev
);
1308 mutex_unlock(&root_udev_mutex
);
1313 kref_put(&udev
->kref
, tcmu_dev_kref_release
);
1314 uio_unregister_device(&udev
->uio_info
);
1316 vfree(udev
->mb_addr
);
1324 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd
*cmd
)
1326 if (test_bit(TCMU_CMD_BIT_EXPIRED
, &cmd
->flags
)) {
1327 kmem_cache_free(tcmu_cmd_cache
, cmd
);
1333 static bool tcmu_dev_configured(struct tcmu_dev
*udev
)
1335 return udev
->uio_info
.uio_dev
? true : false;
1338 static void tcmu_blocks_release(struct tcmu_dev
*udev
)
1343 /* Try to release all block pages */
1344 mutex_lock(&udev
->cmdr_lock
);
1345 for (i
= 0; i
<= udev
->dbi_max
; i
++) {
1346 page
= radix_tree_delete(&udev
->data_blocks
, i
);
1349 atomic_dec(&global_db_count
);
1352 mutex_unlock(&udev
->cmdr_lock
);
1355 static void tcmu_free_device(struct se_device
*dev
)
1357 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1358 struct tcmu_cmd
*cmd
;
1359 bool all_expired
= true;
1362 del_timer_sync(&udev
->timeout
);
1364 mutex_lock(&root_udev_mutex
);
1365 list_del(&udev
->node
);
1366 mutex_unlock(&root_udev_mutex
);
1368 vfree(udev
->mb_addr
);
1370 /* Upper layer should drain all requests before calling this */
1371 spin_lock_irq(&udev
->commands_lock
);
1372 idr_for_each_entry(&udev
->commands
, cmd
, i
) {
1373 if (tcmu_check_and_free_pending_cmd(cmd
) != 0)
1374 all_expired
= false;
1376 idr_destroy(&udev
->commands
);
1377 spin_unlock_irq(&udev
->commands_lock
);
1378 WARN_ON(!all_expired
);
1380 tcmu_blocks_release(udev
);
1382 if (tcmu_dev_configured(udev
)) {
1383 tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE
, udev
->uio_info
.name
,
1384 udev
->uio_info
.uio_dev
->minor
);
1386 uio_unregister_device(&udev
->uio_info
);
1389 /* release ref from init */
1390 kref_put(&udev
->kref
, tcmu_dev_kref_release
);
1394 Opt_dev_config
, Opt_dev_size
, Opt_hw_block_size
, Opt_hw_max_sectors
,
1398 static match_table_t tokens
= {
1399 {Opt_dev_config
, "dev_config=%s"},
1400 {Opt_dev_size
, "dev_size=%u"},
1401 {Opt_hw_block_size
, "hw_block_size=%u"},
1402 {Opt_hw_max_sectors
, "hw_max_sectors=%u"},
1406 static int tcmu_set_dev_attrib(substring_t
*arg
, u32
*dev_attrib
)
1408 unsigned long tmp_ul
;
1412 arg_p
= match_strdup(arg
);
1416 ret
= kstrtoul(arg_p
, 0, &tmp_ul
);
1419 pr_err("kstrtoul() failed for dev attrib\n");
1423 pr_err("dev attrib must be nonzero\n");
1426 *dev_attrib
= tmp_ul
;
1430 static ssize_t
tcmu_set_configfs_dev_params(struct se_device
*dev
,
1431 const char *page
, ssize_t count
)
1433 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1434 char *orig
, *ptr
, *opts
, *arg_p
;
1435 substring_t args
[MAX_OPT_ARGS
];
1438 opts
= kstrdup(page
, GFP_KERNEL
);
1444 while ((ptr
= strsep(&opts
, ",\n")) != NULL
) {
1448 token
= match_token(ptr
, tokens
, args
);
1450 case Opt_dev_config
:
1451 if (match_strlcpy(udev
->dev_config
, &args
[0],
1452 TCMU_CONFIG_LEN
) == 0) {
1456 pr_debug("TCMU: Referencing Path: %s\n", udev
->dev_config
);
1459 arg_p
= match_strdup(&args
[0]);
1464 ret
= kstrtoul(arg_p
, 0, (unsigned long *) &udev
->dev_size
);
1467 pr_err("kstrtoul() failed for dev_size=\n");
1469 case Opt_hw_block_size
:
1470 ret
= tcmu_set_dev_attrib(&args
[0],
1471 &(dev
->dev_attrib
.hw_block_size
));
1473 case Opt_hw_max_sectors
:
1474 ret
= tcmu_set_dev_attrib(&args
[0],
1475 &(dev
->dev_attrib
.hw_max_sectors
));
1486 return (!ret
) ? count
: ret
;
1489 static ssize_t
tcmu_show_configfs_dev_params(struct se_device
*dev
, char *b
)
1491 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1494 bl
= sprintf(b
+ bl
, "Config: %s ",
1495 udev
->dev_config
[0] ? udev
->dev_config
: "NULL");
1496 bl
+= sprintf(b
+ bl
, "Size: %zu\n", udev
->dev_size
);
1501 static sector_t
tcmu_get_blocks(struct se_device
*dev
)
1503 struct tcmu_dev
*udev
= TCMU_DEV(dev
);
1505 return div_u64(udev
->dev_size
- dev
->dev_attrib
.block_size
,
1506 dev
->dev_attrib
.block_size
);
1509 static sense_reason_t
1510 tcmu_parse_cdb(struct se_cmd
*cmd
)
1512 return passthrough_parse_cdb(cmd
, tcmu_queue_cmd
);
1515 static ssize_t
tcmu_cmd_time_out_show(struct config_item
*item
, char *page
)
1517 struct se_dev_attrib
*da
= container_of(to_config_group(item
),
1518 struct se_dev_attrib
, da_group
);
1519 struct tcmu_dev
*udev
= container_of(da
->da_dev
,
1520 struct tcmu_dev
, se_dev
);
1522 return snprintf(page
, PAGE_SIZE
, "%lu\n", udev
->cmd_time_out
/ MSEC_PER_SEC
);
1525 static ssize_t
tcmu_cmd_time_out_store(struct config_item
*item
, const char *page
,
1528 struct se_dev_attrib
*da
= container_of(to_config_group(item
),
1529 struct se_dev_attrib
, da_group
);
1530 struct tcmu_dev
*udev
= container_of(da
->da_dev
,
1531 struct tcmu_dev
, se_dev
);
1535 if (da
->da_dev
->export_count
) {
1536 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
1540 ret
= kstrtou32(page
, 0, &val
);
1544 udev
->cmd_time_out
= val
* MSEC_PER_SEC
;
1547 CONFIGFS_ATTR(tcmu_
, cmd_time_out
);
1549 static struct configfs_attribute
**tcmu_attrs
;
1551 static struct target_backend_ops tcmu_ops
= {
1553 .owner
= THIS_MODULE
,
1554 .transport_flags
= TRANSPORT_FLAG_PASSTHROUGH
,
1555 .attach_hba
= tcmu_attach_hba
,
1556 .detach_hba
= tcmu_detach_hba
,
1557 .alloc_device
= tcmu_alloc_device
,
1558 .configure_device
= tcmu_configure_device
,
1559 .free_device
= tcmu_free_device
,
1560 .parse_cdb
= tcmu_parse_cdb
,
1561 .set_configfs_dev_params
= tcmu_set_configfs_dev_params
,
1562 .show_configfs_dev_params
= tcmu_show_configfs_dev_params
,
1563 .get_device_type
= sbc_get_device_type
,
1564 .get_blocks
= tcmu_get_blocks
,
1565 .tb_dev_attrib_attrs
= NULL
,
1568 static int unmap_thread_fn(void *data
)
1570 struct tcmu_dev
*udev
;
1572 uint32_t start
, end
, block
;
1577 DEFINE_WAIT(__wait
);
1579 prepare_to_wait(&unmap_wait
, &__wait
, TASK_INTERRUPTIBLE
);
1581 finish_wait(&unmap_wait
, &__wait
);
1583 if (kthread_should_stop())
1586 mutex_lock(&root_udev_mutex
);
1587 list_for_each_entry(udev
, &root_udev
, node
) {
1588 mutex_lock(&udev
->cmdr_lock
);
1590 /* Try to complete the finished commands first */
1591 tcmu_handle_completions(udev
);
1593 /* Skip the udevs waiting the global pool or in idle */
1594 if (udev
->waiting_global
|| !udev
->dbi_thresh
) {
1595 mutex_unlock(&udev
->cmdr_lock
);
1599 end
= udev
->dbi_max
+ 1;
1600 block
= find_last_bit(udev
->data_bitmap
, end
);
1601 if (block
== udev
->dbi_max
) {
1603 * The last bit is dbi_max, so there is
1604 * no need to shrink any blocks.
1606 mutex_unlock(&udev
->cmdr_lock
);
1608 } else if (block
== end
) {
1609 /* The current udev will goto idle state */
1610 udev
->dbi_thresh
= start
= 0;
1613 udev
->dbi_thresh
= start
= block
+ 1;
1614 udev
->dbi_max
= block
;
1617 /* Here will truncate the data area from off */
1618 off
= udev
->data_off
+ start
* DATA_BLOCK_SIZE
;
1619 unmap_mapping_range(udev
->inode
->i_mapping
, off
, 0, 1);
1621 /* Release the block pages */
1622 for (i
= start
; i
< end
; i
++) {
1623 page
= radix_tree_delete(&udev
->data_blocks
, i
);
1626 atomic_dec(&global_db_count
);
1629 mutex_unlock(&udev
->cmdr_lock
);
1633 * Try to wake up the udevs who are waiting
1634 * for the global data pool.
1636 list_for_each_entry(udev
, &root_udev
, node
) {
1637 if (udev
->waiting_global
)
1638 wake_up(&udev
->wait_cmdr
);
1640 mutex_unlock(&root_udev_mutex
);
1646 static int __init
tcmu_module_init(void)
1648 int ret
, i
, len
= 0;
1650 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry
) % TCMU_OP_ALIGN_SIZE
) != 0);
1652 tcmu_cmd_cache
= kmem_cache_create("tcmu_cmd_cache",
1653 sizeof(struct tcmu_cmd
),
1654 __alignof__(struct tcmu_cmd
),
1656 if (!tcmu_cmd_cache
)
1659 tcmu_root_device
= root_device_register("tcm_user");
1660 if (IS_ERR(tcmu_root_device
)) {
1661 ret
= PTR_ERR(tcmu_root_device
);
1662 goto out_free_cache
;
1665 ret
= genl_register_family(&tcmu_genl_family
);
1667 goto out_unreg_device
;
1670 for (i
= 0; passthrough_attrib_attrs
[i
] != NULL
; i
++) {
1671 len
+= sizeof(struct configfs_attribute
*);
1673 len
+= sizeof(struct configfs_attribute
*) * 2;
1675 tcmu_attrs
= kzalloc(len
, GFP_KERNEL
);
1678 goto out_unreg_genl
;
1681 for (i
= 0; passthrough_attrib_attrs
[i
] != NULL
; i
++) {
1682 tcmu_attrs
[i
] = passthrough_attrib_attrs
[i
];
1684 tcmu_attrs
[i
] = &tcmu_attr_cmd_time_out
;
1685 tcmu_ops
.tb_dev_attrib_attrs
= tcmu_attrs
;
1687 ret
= transport_backend_register(&tcmu_ops
);
1691 init_waitqueue_head(&unmap_wait
);
1692 unmap_thread
= kthread_run(unmap_thread_fn
, NULL
, "tcmu_unmap");
1693 if (IS_ERR(unmap_thread
)) {
1694 ret
= PTR_ERR(unmap_thread
);
1695 goto out_unreg_transport
;
1700 out_unreg_transport
:
1701 target_backend_unregister(&tcmu_ops
);
1705 genl_unregister_family(&tcmu_genl_family
);
1707 root_device_unregister(tcmu_root_device
);
1709 kmem_cache_destroy(tcmu_cmd_cache
);
1714 static void __exit
tcmu_module_exit(void)
1716 kthread_stop(unmap_thread
);
1717 target_backend_unregister(&tcmu_ops
);
1719 genl_unregister_family(&tcmu_genl_family
);
1720 root_device_unregister(tcmu_root_device
);
1721 kmem_cache_destroy(tcmu_cmd_cache
);
1724 MODULE_DESCRIPTION("TCM USER subsystem plugin");
1725 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
1726 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
1727 MODULE_LICENSE("GPL");
1729 module_init(tcmu_module_init
);
1730 module_exit(tcmu_module_exit
);