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/workqueue.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>
50 * Define a shared-memory interface for LIO to pass SCSI commands and
51 * data to userspace for processing. This is to allow backends that
52 * are too complex for in-kernel support to be possible.
54 * It uses the UIO framework to do a lot of the device-creation and
55 * introspection work for us.
57 * See the .h file for how the ring is laid out. Note that while the
58 * command ring is defined, the particulars of the data area are
59 * not. Offset values in the command entry point to other locations
60 * internal to the mmap-ed area. There is separate space outside the
61 * command ring for data buffers. This leaves maximum flexibility for
62 * moving buffer allocations, or even page flipping or other
63 * allocation techniques, without altering the command ring layout.
66 * The user process must be assumed to be malicious. There's no way to
67 * prevent it breaking the command ring protocol if it wants, but in
68 * order to prevent other issues we must only ever read *data* from
69 * the shared memory area, not offsets or sizes. This applies to
70 * command ring entries as well as the mailbox. Extra code needed for
71 * this may have a 'UAM' comment.
74 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
76 /* For cmd area, the size is fixed 8MB */
77 #define CMDR_SIZE (8 * 1024 * 1024)
80 * For data area, the block size is PAGE_SIZE and
81 * the total size is 256K * PAGE_SIZE.
83 #define DATA_BLOCK_SIZE PAGE_SIZE
84 #define DATA_BLOCK_SHIFT PAGE_SHIFT
85 #define DATA_BLOCK_BITS_DEF (256 * 1024)
87 #define TCMU_MBS_TO_BLOCKS(_mbs) (_mbs << (20 - DATA_BLOCK_SHIFT))
88 #define TCMU_BLOCKS_TO_MBS(_blocks) (_blocks >> (20 - DATA_BLOCK_SHIFT))
91 * Default number of global data blocks(512K * PAGE_SIZE)
92 * when the unmap thread will be started.
94 #define TCMU_GLOBAL_MAX_BLOCKS_DEF (512 * 1024)
96 static u8 tcmu_kern_cmd_reply_supported;
97 static u8 tcmu_netlink_blocked;
99 static struct device *tcmu_root_device;
105 #define TCMU_CONFIG_LEN 256
107 static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
108 static LIST_HEAD(tcmu_nl_cmd_list);
113 /* wake up thread waiting for reply */
114 struct completion complete;
115 struct list_head nl_list;
116 struct tcmu_dev *udev;
122 struct list_head node;
125 struct se_device se_dev;
130 #define TCMU_DEV_BIT_OPEN 0
131 #define TCMU_DEV_BIT_BROKEN 1
132 #define TCMU_DEV_BIT_BLOCKED 2
135 struct uio_info uio_info;
139 struct tcmu_mailbox *mb_addr;
142 u32 cmdr_last_cleaned;
143 /* Offset of data area from start of mb */
144 /* Must add data_off and mb_addr to get the address */
150 struct mutex cmdr_lock;
151 struct list_head qfull_queue;
155 unsigned long *data_bitmap;
156 struct radix_tree_root data_blocks;
160 struct timer_list cmd_timer;
161 unsigned int cmd_time_out;
162 struct list_head inflight_queue;
164 struct timer_list qfull_timer;
167 struct list_head timedout_entry;
169 struct tcmu_nl_cmd curr_nl_cmd;
171 char dev_config[TCMU_CONFIG_LEN];
173 int nl_reply_supported;
176 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
178 #define CMDR_OFF sizeof(struct tcmu_mailbox)
181 struct se_cmd *se_cmd;
182 struct tcmu_dev *tcmu_dev;
183 struct list_head queue_entry;
187 /* Can't use se_cmd when cleaning up expired cmds, because if
188 cmd has been completed then accessing se_cmd is off limits */
193 unsigned long deadline;
195 #define TCMU_CMD_BIT_EXPIRED 0
196 #define TCMU_CMD_BIT_INFLIGHT 1
200 * To avoid dead lock the mutex lock order should always be:
202 * mutex_lock(&root_udev_mutex);
204 * mutex_lock(&tcmu_dev->cmdr_lock);
205 * mutex_unlock(&tcmu_dev->cmdr_lock);
207 * mutex_unlock(&root_udev_mutex);
209 static DEFINE_MUTEX(root_udev_mutex);
210 static LIST_HEAD(root_udev);
212 static DEFINE_SPINLOCK(timed_out_udevs_lock);
213 static LIST_HEAD(timed_out_udevs);
215 static struct kmem_cache *tcmu_cmd_cache;
217 static atomic_t global_db_count = ATOMIC_INIT(0);
218 static struct delayed_work tcmu_unmap_work;
219 static int tcmu_global_max_blocks = TCMU_GLOBAL_MAX_BLOCKS_DEF;
221 static int tcmu_set_global_max_data_area(const char *str,
222 const struct kernel_param *kp)
224 int ret, max_area_mb;
226 ret = kstrtoint(str, 10, &max_area_mb);
230 if (max_area_mb <= 0) {
231 pr_err("global_max_data_area must be larger than 0.\n");
235 tcmu_global_max_blocks = TCMU_MBS_TO_BLOCKS(max_area_mb);
236 if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
237 schedule_delayed_work(&tcmu_unmap_work, 0);
239 cancel_delayed_work_sync(&tcmu_unmap_work);
244 static int tcmu_get_global_max_data_area(char *buffer,
245 const struct kernel_param *kp)
247 return sprintf(buffer, "%d", TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
250 static const struct kernel_param_ops tcmu_global_max_data_area_op = {
251 .set = tcmu_set_global_max_data_area,
252 .get = tcmu_get_global_max_data_area,
255 module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
257 MODULE_PARM_DESC(global_max_data_area_mb,
258 "Max MBs allowed to be allocated to all the tcmu device's "
261 static int tcmu_get_block_netlink(char *buffer,
262 const struct kernel_param *kp)
264 return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
265 "blocked" : "unblocked");
268 static int tcmu_set_block_netlink(const char *str,
269 const struct kernel_param *kp)
274 ret = kstrtou8(str, 0, &val);
279 pr_err("Invalid block netlink value %u\n", val);
283 tcmu_netlink_blocked = val;
287 static const struct kernel_param_ops tcmu_block_netlink_op = {
288 .set = tcmu_set_block_netlink,
289 .get = tcmu_get_block_netlink,
292 module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
293 MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
295 static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
297 struct tcmu_dev *udev = nl_cmd->udev;
299 if (!tcmu_netlink_blocked) {
300 pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
304 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
305 pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
306 nl_cmd->status = -EINTR;
307 list_del(&nl_cmd->nl_list);
308 complete(&nl_cmd->complete);
313 static int tcmu_set_reset_netlink(const char *str,
314 const struct kernel_param *kp)
316 struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
320 ret = kstrtou8(str, 0, &val);
325 pr_err("Invalid reset netlink value %u\n", val);
329 mutex_lock(&tcmu_nl_cmd_mutex);
330 list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
331 ret = tcmu_fail_netlink_cmd(nl_cmd);
335 mutex_unlock(&tcmu_nl_cmd_mutex);
340 static const struct kernel_param_ops tcmu_reset_netlink_op = {
341 .set = tcmu_set_reset_netlink,
344 module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
345 MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
347 /* multicast group */
348 enum tcmu_multicast_groups {
352 static const struct genl_multicast_group tcmu_mcgrps[] = {
353 [TCMU_MCGRP_CONFIG] = { .name = "config", },
356 static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
357 [TCMU_ATTR_DEVICE] = { .type = NLA_STRING },
358 [TCMU_ATTR_MINOR] = { .type = NLA_U32 },
359 [TCMU_ATTR_CMD_STATUS] = { .type = NLA_S32 },
360 [TCMU_ATTR_DEVICE_ID] = { .type = NLA_U32 },
361 [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
364 static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
366 struct tcmu_dev *udev = NULL;
367 struct tcmu_nl_cmd *nl_cmd;
368 int dev_id, rc, ret = 0;
370 if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
371 !info->attrs[TCMU_ATTR_DEVICE_ID]) {
372 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
376 dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
377 rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
379 mutex_lock(&tcmu_nl_cmd_mutex);
380 list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
381 if (nl_cmd->udev->se_dev.dev_index == dev_id) {
388 pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
389 completed_cmd, rc, dev_id);
393 list_del(&nl_cmd->nl_list);
395 pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
396 udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
399 if (nl_cmd->cmd != completed_cmd) {
400 pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
401 udev->name, completed_cmd, nl_cmd->cmd);
407 complete(&nl_cmd->complete);
409 mutex_unlock(&tcmu_nl_cmd_mutex);
413 static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
415 return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
418 static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
420 return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
423 static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
424 struct genl_info *info)
426 return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
429 static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
431 if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
432 tcmu_kern_cmd_reply_supported =
433 nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
434 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
435 tcmu_kern_cmd_reply_supported);
441 static const struct genl_ops tcmu_genl_ops[] = {
443 .cmd = TCMU_CMD_SET_FEATURES,
444 .flags = GENL_ADMIN_PERM,
445 .policy = tcmu_attr_policy,
446 .doit = tcmu_genl_set_features,
449 .cmd = TCMU_CMD_ADDED_DEVICE_DONE,
450 .flags = GENL_ADMIN_PERM,
451 .policy = tcmu_attr_policy,
452 .doit = tcmu_genl_add_dev_done,
455 .cmd = TCMU_CMD_REMOVED_DEVICE_DONE,
456 .flags = GENL_ADMIN_PERM,
457 .policy = tcmu_attr_policy,
458 .doit = tcmu_genl_rm_dev_done,
461 .cmd = TCMU_CMD_RECONFIG_DEVICE_DONE,
462 .flags = GENL_ADMIN_PERM,
463 .policy = tcmu_attr_policy,
464 .doit = tcmu_genl_reconfig_dev_done,
468 /* Our generic netlink family */
469 static struct genl_family tcmu_genl_family __ro_after_init = {
470 .module = THIS_MODULE,
474 .maxattr = TCMU_ATTR_MAX,
475 .mcgrps = tcmu_mcgrps,
476 .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
478 .ops = tcmu_genl_ops,
479 .n_ops = ARRAY_SIZE(tcmu_genl_ops),
482 #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
483 #define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
484 #define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
485 #define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
487 static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
489 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
492 for (i = 0; i < len; i++)
493 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
496 static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
497 struct tcmu_cmd *tcmu_cmd)
502 dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
503 if (dbi == udev->dbi_thresh)
506 page = radix_tree_lookup(&udev->data_blocks, dbi);
508 if (atomic_add_return(1, &global_db_count) >
509 tcmu_global_max_blocks)
510 schedule_delayed_work(&tcmu_unmap_work, 0);
512 /* try to get new page from the mm */
513 page = alloc_page(GFP_KERNEL);
517 ret = radix_tree_insert(&udev->data_blocks, dbi, page);
522 if (dbi > udev->dbi_max)
525 set_bit(dbi, udev->data_bitmap);
526 tcmu_cmd_set_dbi(tcmu_cmd, dbi);
532 atomic_dec(&global_db_count);
536 static bool tcmu_get_empty_blocks(struct tcmu_dev *udev,
537 struct tcmu_cmd *tcmu_cmd)
541 for (i = tcmu_cmd->dbi_cur; i < tcmu_cmd->dbi_cnt; i++) {
542 if (!tcmu_get_empty_block(udev, tcmu_cmd))
548 static inline struct page *
549 tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
551 return radix_tree_lookup(&udev->data_blocks, dbi);
554 static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
556 kfree(tcmu_cmd->dbi);
557 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
560 static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd)
562 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
563 size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE);
565 if (se_cmd->se_cmd_flags & SCF_BIDI) {
566 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
567 data_length += round_up(se_cmd->t_bidi_data_sg->length,
574 static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd)
576 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
578 return data_length / DATA_BLOCK_SIZE;
581 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
583 struct se_device *se_dev = se_cmd->se_dev;
584 struct tcmu_dev *udev = TCMU_DEV(se_dev);
585 struct tcmu_cmd *tcmu_cmd;
587 tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL);
591 INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
592 tcmu_cmd->se_cmd = se_cmd;
593 tcmu_cmd->tcmu_dev = udev;
595 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
596 tcmu_cmd->dbi_cnt = tcmu_cmd_get_block_cnt(tcmu_cmd);
597 tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
599 if (!tcmu_cmd->dbi) {
600 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
607 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
609 unsigned long offset = offset_in_page(vaddr);
610 void *start = vaddr - offset;
612 size = round_up(size+offset, PAGE_SIZE);
615 flush_dcache_page(virt_to_page(start));
622 * Some ring helper functions. We don't assume size is a power of 2 so
623 * we can't use circ_buf.h.
625 static inline size_t spc_used(size_t head, size_t tail, size_t size)
627 int diff = head - tail;
635 static inline size_t spc_free(size_t head, size_t tail, size_t size)
637 /* Keep 1 byte unused or we can't tell full from empty */
638 return (size - spc_used(head, tail, size) - 1);
641 static inline size_t head_to_end(size_t head, size_t size)
646 static inline void new_iov(struct iovec **iov, int *iov_cnt)
655 memset(iovec, 0, sizeof(struct iovec));
658 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
660 /* offset is relative to mb_addr */
661 static inline size_t get_block_offset_user(struct tcmu_dev *dev,
662 int dbi, int remaining)
664 return dev->data_off + dbi * DATA_BLOCK_SIZE +
665 DATA_BLOCK_SIZE - remaining;
668 static inline size_t iov_tail(struct iovec *iov)
670 return (size_t)iov->iov_base + iov->iov_len;
673 static void scatter_data_area(struct tcmu_dev *udev,
674 struct tcmu_cmd *tcmu_cmd, struct scatterlist *data_sg,
675 unsigned int data_nents, struct iovec **iov,
676 int *iov_cnt, bool copy_data)
679 int block_remaining = 0;
680 void *from, *to = NULL;
681 size_t copy_bytes, to_offset, offset;
682 struct scatterlist *sg;
685 for_each_sg(data_sg, sg, data_nents, i) {
686 int sg_remaining = sg->length;
687 from = kmap_atomic(sg_page(sg)) + sg->offset;
688 while (sg_remaining > 0) {
689 if (block_remaining == 0) {
693 block_remaining = DATA_BLOCK_SIZE;
694 dbi = tcmu_cmd_get_dbi(tcmu_cmd);
695 page = tcmu_get_block_page(udev, dbi);
696 to = kmap_atomic(page);
700 * Covert to virtual offset of the ring data area.
702 to_offset = get_block_offset_user(udev, dbi,
706 * The following code will gather and map the blocks
707 * to the same iovec when the blocks are all next to
710 copy_bytes = min_t(size_t, sg_remaining,
713 to_offset == iov_tail(*iov)) {
715 * Will append to the current iovec, because
716 * the current block page is next to the
719 (*iov)->iov_len += copy_bytes;
722 * Will allocate a new iovec because we are
723 * first time here or the current block page
724 * is not next to the previous one.
726 new_iov(iov, iov_cnt);
727 (*iov)->iov_base = (void __user *)to_offset;
728 (*iov)->iov_len = copy_bytes;
732 offset = DATA_BLOCK_SIZE - block_remaining;
734 from + sg->length - sg_remaining,
736 tcmu_flush_dcache_range(to, copy_bytes);
739 sg_remaining -= copy_bytes;
740 block_remaining -= copy_bytes;
742 kunmap_atomic(from - sg->offset);
749 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
750 bool bidi, uint32_t read_len)
752 struct se_cmd *se_cmd = cmd->se_cmd;
754 int block_remaining = 0;
755 void *from = NULL, *to;
756 size_t copy_bytes, offset;
757 struct scatterlist *sg, *data_sg;
759 unsigned int data_nents;
763 data_sg = se_cmd->t_data_sg;
764 data_nents = se_cmd->t_data_nents;
768 * For bidi case, the first count blocks are for Data-Out
769 * buffer blocks, and before gathering the Data-In buffer
770 * the Data-Out buffer blocks should be discarded.
772 count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
774 data_sg = se_cmd->t_bidi_data_sg;
775 data_nents = se_cmd->t_bidi_data_nents;
778 tcmu_cmd_set_dbi_cur(cmd, count);
780 for_each_sg(data_sg, sg, data_nents, i) {
781 int sg_remaining = sg->length;
782 to = kmap_atomic(sg_page(sg)) + sg->offset;
783 while (sg_remaining > 0 && read_len > 0) {
784 if (block_remaining == 0) {
788 block_remaining = DATA_BLOCK_SIZE;
789 dbi = tcmu_cmd_get_dbi(cmd);
790 page = tcmu_get_block_page(udev, dbi);
791 from = kmap_atomic(page);
793 copy_bytes = min_t(size_t, sg_remaining,
795 if (read_len < copy_bytes)
796 copy_bytes = read_len;
797 offset = DATA_BLOCK_SIZE - block_remaining;
798 tcmu_flush_dcache_range(from, copy_bytes);
799 memcpy(to + sg->length - sg_remaining, from + offset,
802 sg_remaining -= copy_bytes;
803 block_remaining -= copy_bytes;
804 read_len -= copy_bytes;
806 kunmap_atomic(to - sg->offset);
814 static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
816 return thresh - bitmap_weight(bitmap, thresh);
820 * We can't queue a command until we have space available on the cmd ring *and*
821 * space available on the data area.
823 * Called with ring lock held.
825 static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
826 size_t cmd_size, size_t data_needed)
828 struct tcmu_mailbox *mb = udev->mb_addr;
829 uint32_t blocks_needed = (data_needed + DATA_BLOCK_SIZE - 1)
831 size_t space, cmd_needed;
834 tcmu_flush_dcache_range(mb, sizeof(*mb));
836 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
839 * If cmd end-of-ring space is too small then we need space for a NOP plus
840 * original cmd - cmds are internally contiguous.
842 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
843 cmd_needed = cmd_size;
845 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
847 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
848 if (space < cmd_needed) {
849 pr_debug("no cmd space: %u %u %u\n", cmd_head,
850 udev->cmdr_last_cleaned, udev->cmdr_size);
854 /* try to check and get the data blocks as needed */
855 space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
856 if ((space * DATA_BLOCK_SIZE) < data_needed) {
857 unsigned long blocks_left =
858 (udev->max_blocks - udev->dbi_thresh) + space;
860 if (blocks_left < blocks_needed) {
861 pr_debug("no data space: only %lu available, but ask for %zu\n",
862 blocks_left * DATA_BLOCK_SIZE,
867 udev->dbi_thresh += blocks_needed;
868 if (udev->dbi_thresh > udev->max_blocks)
869 udev->dbi_thresh = udev->max_blocks;
872 return tcmu_get_empty_blocks(udev, cmd);
875 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
877 return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
878 sizeof(struct tcmu_cmd_entry));
881 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
882 size_t base_command_size)
884 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
887 command_size = base_command_size +
888 round_up(scsi_command_size(se_cmd->t_task_cdb),
891 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
896 static int tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
897 struct timer_list *timer)
899 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
902 if (tcmu_cmd->cmd_id)
905 cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT);
907 pr_err("tcmu: Could not allocate cmd id.\n");
910 tcmu_cmd->cmd_id = cmd_id;
912 pr_debug("allocated cmd %u for dev %s tmo %lu\n", tcmu_cmd->cmd_id,
913 udev->name, tmo / MSEC_PER_SEC);
919 tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
920 if (!timer_pending(timer))
921 mod_timer(timer, tcmu_cmd->deadline);
926 static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
928 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
933 * For backwards compat if qfull_time_out is not set use
934 * cmd_time_out and if that's not set use the default time out.
936 if (!udev->qfull_time_out)
938 else if (udev->qfull_time_out > 0)
939 tmo = udev->qfull_time_out;
940 else if (udev->cmd_time_out)
941 tmo = udev->cmd_time_out;
945 ret = tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
949 list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
950 pr_debug("adding cmd %u on dev %s to ring space wait queue\n",
951 tcmu_cmd->cmd_id, udev->name);
956 * queue_cmd_ring - queue cmd to ring or internally
957 * @tcmu_cmd: cmd to queue
958 * @scsi_err: TCM error code if failure (-1) returned.
961 * -1 we cannot queue internally or to the ring.
963 * 1 internally queued to wait for ring memory to free.
965 static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
967 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
968 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
969 size_t base_command_size, command_size;
970 struct tcmu_mailbox *mb;
971 struct tcmu_cmd_entry *entry;
976 bool copy_to_data_area;
977 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
979 *scsi_err = TCM_NO_SENSE;
981 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
982 *scsi_err = TCM_LUN_BUSY;
986 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
987 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
992 * Must be a certain minimum size for response sense info, but
993 * also may be larger if the iov array is large.
995 * We prepare as many iovs as possbile for potential uses here,
996 * because it's expensive to tell how many regions are freed in
997 * the bitmap & global data pool, as the size calculated here
998 * will only be used to do the checks.
1000 * The size will be recalculated later as actually needed to save
1001 * cmd area memories.
1003 base_command_size = tcmu_cmd_get_base_cmd_size(tcmu_cmd->dbi_cnt);
1004 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1006 if (!list_empty(&udev->qfull_queue))
1010 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
1011 if ((command_size > (udev->cmdr_size / 2)) ||
1012 data_length > udev->data_size) {
1013 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
1014 "cmd ring/data area\n", command_size, data_length,
1015 udev->cmdr_size, udev->data_size);
1016 *scsi_err = TCM_INVALID_CDB_FIELD;
1020 if (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) {
1022 * Don't leave commands partially setup because the unmap
1023 * thread might need the blocks to make forward progress.
1025 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1026 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1030 /* Insert a PAD if end-of-ring space is too small */
1031 if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
1032 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
1034 entry = (void *) mb + CMDR_OFF + cmd_head;
1035 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
1036 tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
1037 entry->hdr.cmd_id = 0; /* not used for PAD */
1038 entry->hdr.kflags = 0;
1039 entry->hdr.uflags = 0;
1040 tcmu_flush_dcache_range(entry, sizeof(*entry));
1042 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
1043 tcmu_flush_dcache_range(mb, sizeof(*mb));
1045 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
1046 WARN_ON(cmd_head != 0);
1049 entry = (void *) mb + CMDR_OFF + cmd_head;
1050 memset(entry, 0, command_size);
1051 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1053 /* Handle allocating space from the data area */
1054 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1055 iov = &entry->req.iov[0];
1057 copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE
1058 || se_cmd->se_cmd_flags & SCF_BIDI);
1059 scatter_data_area(udev, tcmu_cmd, se_cmd->t_data_sg,
1060 se_cmd->t_data_nents, &iov, &iov_cnt,
1062 entry->req.iov_cnt = iov_cnt;
1064 /* Handle BIDI commands */
1066 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1068 scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg,
1069 se_cmd->t_bidi_data_nents, &iov, &iov_cnt,
1072 entry->req.iov_bidi_cnt = iov_cnt;
1074 ret = tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out,
1077 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1079 *scsi_err = TCM_OUT_OF_RESOURCES;
1082 entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1085 * Recalaulate the command's base size and size according
1086 * to the actual needs
1088 base_command_size = tcmu_cmd_get_base_cmd_size(entry->req.iov_cnt +
1089 entry->req.iov_bidi_cnt);
1090 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1092 tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1094 /* All offsets relative to mb_addr, not start of entry! */
1095 cdb_off = CMDR_OFF + cmd_head + base_command_size;
1096 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1097 entry->req.cdb_off = cdb_off;
1098 tcmu_flush_dcache_range(entry, sizeof(*entry));
1100 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1101 tcmu_flush_dcache_range(mb, sizeof(*mb));
1103 list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1104 set_bit(TCMU_CMD_BIT_INFLIGHT, &tcmu_cmd->flags);
1106 /* TODO: only if FLUSH and FUA? */
1107 uio_event_notify(&udev->uio_info);
1112 if (add_to_qfull_queue(tcmu_cmd)) {
1113 *scsi_err = TCM_OUT_OF_RESOURCES;
1120 static sense_reason_t
1121 tcmu_queue_cmd(struct se_cmd *se_cmd)
1123 struct se_device *se_dev = se_cmd->se_dev;
1124 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1125 struct tcmu_cmd *tcmu_cmd;
1126 sense_reason_t scsi_ret;
1129 tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1131 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1133 mutex_lock(&udev->cmdr_lock);
1134 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1135 mutex_unlock(&udev->cmdr_lock);
1137 tcmu_free_cmd(tcmu_cmd);
1141 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1143 struct se_cmd *se_cmd = cmd->se_cmd;
1144 struct tcmu_dev *udev = cmd->tcmu_dev;
1145 bool read_len_valid = false;
1146 uint32_t read_len = se_cmd->data_length;
1149 * cmd has been completed already from timeout, just reclaim
1150 * data area space and free cmd
1152 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
1155 list_del_init(&cmd->queue_entry);
1157 tcmu_cmd_reset_dbi_cur(cmd);
1159 if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1160 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1162 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1166 if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1167 (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1168 read_len_valid = true;
1169 if (entry->rsp.read_len < read_len)
1170 read_len = entry->rsp.read_len;
1173 if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1174 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1175 if (!read_len_valid )
1178 se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1180 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1181 /* Get Data-In buffer before clean up */
1182 gather_data_area(udev, cmd, true, read_len);
1183 } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1184 gather_data_area(udev, cmd, false, read_len);
1185 } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1187 } else if (se_cmd->data_direction != DMA_NONE) {
1188 pr_warn("TCMU: data direction was %d!\n",
1189 se_cmd->data_direction);
1193 if (read_len_valid) {
1194 pr_debug("read_len = %d\n", read_len);
1195 target_complete_cmd_with_length(cmd->se_cmd,
1196 entry->rsp.scsi_status, read_len);
1198 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1202 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1206 static void tcmu_set_next_deadline(struct list_head *queue,
1207 struct timer_list *timer)
1209 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1210 unsigned long deadline = 0;
1212 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, queue, queue_entry) {
1213 if (!time_after(jiffies, tcmu_cmd->deadline)) {
1214 deadline = tcmu_cmd->deadline;
1220 mod_timer(timer, deadline);
1225 static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
1227 struct tcmu_mailbox *mb;
1228 struct tcmu_cmd *cmd;
1231 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1232 pr_err("ring broken, not handling completions\n");
1237 tcmu_flush_dcache_range(mb, sizeof(*mb));
1239 while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1241 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
1243 tcmu_flush_dcache_range(entry, sizeof(*entry));
1245 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) {
1246 UPDATE_HEAD(udev->cmdr_last_cleaned,
1247 tcmu_hdr_get_len(entry->hdr.len_op),
1251 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1253 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
1255 pr_err("cmd_id %u not found, ring is broken\n",
1257 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1261 tcmu_handle_completion(cmd, entry);
1263 UPDATE_HEAD(udev->cmdr_last_cleaned,
1264 tcmu_hdr_get_len(entry->hdr.len_op),
1270 if (mb->cmd_tail == mb->cmd_head) {
1271 /* no more pending commands */
1272 del_timer(&udev->cmd_timer);
1274 if (list_empty(&udev->qfull_queue)) {
1276 * no more pending or waiting commands so try to
1277 * reclaim blocks if needed.
1279 if (atomic_read(&global_db_count) >
1280 tcmu_global_max_blocks)
1281 schedule_delayed_work(&tcmu_unmap_work, 0);
1283 } else if (udev->cmd_time_out) {
1284 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1290 static int tcmu_check_expired_cmd(int id, void *p, void *data)
1292 struct tcmu_cmd *cmd = p;
1293 struct tcmu_dev *udev = cmd->tcmu_dev;
1295 struct se_cmd *se_cmd;
1298 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
1301 if (!time_after(jiffies, cmd->deadline))
1304 is_running = test_bit(TCMU_CMD_BIT_INFLIGHT, &cmd->flags);
1305 se_cmd = cmd->se_cmd;
1309 * If cmd_time_out is disabled but qfull is set deadline
1310 * will only reflect the qfull timeout. Ignore it.
1312 if (!udev->cmd_time_out)
1315 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1317 * target_complete_cmd will translate this to LUN COMM FAILURE
1319 scsi_status = SAM_STAT_CHECK_CONDITION;
1321 idr_remove(&udev->commands, id);
1323 scsi_status = SAM_STAT_TASK_SET_FULL;
1325 list_del_init(&cmd->queue_entry);
1327 pr_debug("Timing out cmd %u on dev %s that is %s.\n",
1328 id, udev->name, is_running ? "inflight" : "queued");
1330 target_complete_cmd(se_cmd, scsi_status);
1334 static void tcmu_device_timedout(struct tcmu_dev *udev)
1336 spin_lock(&timed_out_udevs_lock);
1337 if (list_empty(&udev->timedout_entry))
1338 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1339 spin_unlock(&timed_out_udevs_lock);
1341 schedule_delayed_work(&tcmu_unmap_work, 0);
1344 static void tcmu_cmd_timedout(struct timer_list *t)
1346 struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1348 pr_debug("%s cmd timeout has expired\n", udev->name);
1349 tcmu_device_timedout(udev);
1352 static void tcmu_qfull_timedout(struct timer_list *t)
1354 struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1356 pr_debug("%s qfull timeout has expired\n", udev->name);
1357 tcmu_device_timedout(udev);
1360 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1362 struct tcmu_hba *tcmu_hba;
1364 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1368 tcmu_hba->host_id = host_id;
1369 hba->hba_ptr = tcmu_hba;
1374 static void tcmu_detach_hba(struct se_hba *hba)
1376 kfree(hba->hba_ptr);
1377 hba->hba_ptr = NULL;
1380 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1382 struct tcmu_dev *udev;
1384 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1387 kref_init(&udev->kref);
1389 udev->name = kstrdup(name, GFP_KERNEL);
1396 udev->cmd_time_out = TCMU_TIME_OUT;
1397 udev->qfull_time_out = -1;
1399 udev->max_blocks = DATA_BLOCK_BITS_DEF;
1400 mutex_init(&udev->cmdr_lock);
1402 INIT_LIST_HEAD(&udev->node);
1403 INIT_LIST_HEAD(&udev->timedout_entry);
1404 INIT_LIST_HEAD(&udev->qfull_queue);
1405 INIT_LIST_HEAD(&udev->inflight_queue);
1406 idr_init(&udev->commands);
1408 timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1409 timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1411 INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
1413 return &udev->se_dev;
1416 static bool run_qfull_queue(struct tcmu_dev *udev, bool fail)
1418 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1420 bool drained = true;
1421 sense_reason_t scsi_ret;
1424 if (list_empty(&udev->qfull_queue))
1427 pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1429 list_splice_init(&udev->qfull_queue, &cmds);
1431 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1432 list_del_init(&tcmu_cmd->queue_entry);
1434 pr_debug("removing cmd %u on dev %s from queue\n",
1435 tcmu_cmd->cmd_id, udev->name);
1438 idr_remove(&udev->commands, tcmu_cmd->cmd_id);
1440 * We were not able to even start the command, so
1441 * fail with busy to allow a retry in case runner
1442 * was only temporarily down. If the device is being
1443 * removed then LIO core will do the right thing and
1446 target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1447 tcmu_free_cmd(tcmu_cmd);
1451 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1453 pr_debug("cmd %u on dev %s failed with %u\n",
1454 tcmu_cmd->cmd_id, udev->name, scsi_ret);
1456 idr_remove(&udev->commands, tcmu_cmd->cmd_id);
1458 * Ignore scsi_ret for now. target_complete_cmd
1461 target_complete_cmd(tcmu_cmd->se_cmd,
1462 SAM_STAT_CHECK_CONDITION);
1463 tcmu_free_cmd(tcmu_cmd);
1464 } else if (ret > 0) {
1465 pr_debug("ran out of space during cmdr queue run\n");
1467 * cmd was requeued, so just put all cmds back in
1470 list_splice_tail(&cmds, &udev->qfull_queue);
1476 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1480 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1482 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1484 mutex_lock(&udev->cmdr_lock);
1485 tcmu_handle_completions(udev);
1486 run_qfull_queue(udev, false);
1487 mutex_unlock(&udev->cmdr_lock);
1493 * mmap code from uio.c. Copied here because we want to hook mmap()
1494 * and this stuff must come along.
1496 static int tcmu_find_mem_index(struct vm_area_struct *vma)
1498 struct tcmu_dev *udev = vma->vm_private_data;
1499 struct uio_info *info = &udev->uio_info;
1501 if (vma->vm_pgoff < MAX_UIO_MAPS) {
1502 if (info->mem[vma->vm_pgoff].size == 0)
1504 return (int)vma->vm_pgoff;
1509 static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
1513 mutex_lock(&udev->cmdr_lock);
1514 page = tcmu_get_block_page(udev, dbi);
1516 mutex_unlock(&udev->cmdr_lock);
1521 * Userspace messed up and passed in a address not in the
1522 * data iov passed to it.
1524 pr_err("Invalid addr to data block mapping (dbi %u) on device %s\n",
1527 mutex_unlock(&udev->cmdr_lock);
1532 static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1534 struct tcmu_dev *udev = vmf->vma->vm_private_data;
1535 struct uio_info *info = &udev->uio_info;
1537 unsigned long offset;
1540 int mi = tcmu_find_mem_index(vmf->vma);
1542 return VM_FAULT_SIGBUS;
1545 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1548 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1550 if (offset < udev->data_off) {
1551 /* For the vmalloc()ed cmd area pages */
1552 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1553 page = vmalloc_to_page(addr);
1557 /* For the dynamically growing data area pages */
1558 dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
1559 page = tcmu_try_get_block_page(udev, dbi);
1561 return VM_FAULT_SIGBUS;
1569 static const struct vm_operations_struct tcmu_vm_ops = {
1570 .fault = tcmu_vma_fault,
1573 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1575 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1577 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1578 vma->vm_ops = &tcmu_vm_ops;
1580 vma->vm_private_data = udev;
1582 /* Ensure the mmap is exactly the right size */
1583 if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
1589 static int tcmu_open(struct uio_info *info, struct inode *inode)
1591 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1593 /* O_EXCL not supported for char devs, so fake it? */
1594 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1597 udev->inode = inode;
1598 kref_get(&udev->kref);
1605 static void tcmu_dev_call_rcu(struct rcu_head *p)
1607 struct se_device *dev = container_of(p, struct se_device, rcu_head);
1608 struct tcmu_dev *udev = TCMU_DEV(dev);
1610 kfree(udev->uio_info.name);
1615 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1617 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1618 kmem_cache_free(tcmu_cmd_cache, cmd);
1624 static void tcmu_blocks_release(struct radix_tree_root *blocks,
1630 for (i = start; i < end; i++) {
1631 page = radix_tree_delete(blocks, i);
1634 atomic_dec(&global_db_count);
1639 static void tcmu_dev_kref_release(struct kref *kref)
1641 struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1642 struct se_device *dev = &udev->se_dev;
1643 struct tcmu_cmd *cmd;
1644 bool all_expired = true;
1647 vfree(udev->mb_addr);
1648 udev->mb_addr = NULL;
1650 spin_lock_bh(&timed_out_udevs_lock);
1651 if (!list_empty(&udev->timedout_entry))
1652 list_del(&udev->timedout_entry);
1653 spin_unlock_bh(&timed_out_udevs_lock);
1655 /* Upper layer should drain all requests before calling this */
1656 mutex_lock(&udev->cmdr_lock);
1657 idr_for_each_entry(&udev->commands, cmd, i) {
1658 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1659 all_expired = false;
1661 idr_destroy(&udev->commands);
1662 WARN_ON(!all_expired);
1664 tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
1665 kfree(udev->data_bitmap);
1666 mutex_unlock(&udev->cmdr_lock);
1668 call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1671 static int tcmu_release(struct uio_info *info, struct inode *inode)
1673 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1675 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1677 pr_debug("close\n");
1678 /* release ref from open */
1679 kref_put(&udev->kref, tcmu_dev_kref_release);
1683 static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1685 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1687 if (!tcmu_kern_cmd_reply_supported)
1690 if (udev->nl_reply_supported <= 0)
1693 mutex_lock(&tcmu_nl_cmd_mutex);
1695 if (tcmu_netlink_blocked) {
1696 mutex_unlock(&tcmu_nl_cmd_mutex);
1697 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1702 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1703 mutex_unlock(&tcmu_nl_cmd_mutex);
1704 pr_warn("netlink cmd %d already executing on %s\n",
1705 nl_cmd->cmd, udev->name);
1709 memset(nl_cmd, 0, sizeof(*nl_cmd));
1711 nl_cmd->udev = udev;
1712 init_completion(&nl_cmd->complete);
1713 INIT_LIST_HEAD(&nl_cmd->nl_list);
1715 list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
1717 mutex_unlock(&tcmu_nl_cmd_mutex);
1721 static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1723 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1726 if (!tcmu_kern_cmd_reply_supported)
1729 if (udev->nl_reply_supported <= 0)
1732 pr_debug("sleeping for nl reply\n");
1733 wait_for_completion(&nl_cmd->complete);
1735 mutex_lock(&tcmu_nl_cmd_mutex);
1736 nl_cmd->cmd = TCMU_CMD_UNSPEC;
1737 ret = nl_cmd->status;
1738 mutex_unlock(&tcmu_nl_cmd_mutex);
1743 static int tcmu_netlink_event_init(struct tcmu_dev *udev,
1744 enum tcmu_genl_cmd cmd,
1745 struct sk_buff **buf, void **hdr)
1747 struct sk_buff *skb;
1751 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1755 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
1759 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
1763 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
1767 ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
1780 static int tcmu_netlink_event_send(struct tcmu_dev *udev,
1781 enum tcmu_genl_cmd cmd,
1782 struct sk_buff *skb, void *msg_header)
1786 genlmsg_end(skb, msg_header);
1788 ret = tcmu_init_genl_cmd_reply(udev, cmd);
1794 ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
1795 TCMU_MCGRP_CONFIG, GFP_KERNEL);
1796 /* We don't care if no one is listening */
1800 ret = tcmu_wait_genl_cmd_reply(udev);
1804 static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
1806 struct sk_buff *skb = NULL;
1807 void *msg_header = NULL;
1810 ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
1814 return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
1818 static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
1820 struct sk_buff *skb = NULL;
1821 void *msg_header = NULL;
1824 ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
1828 return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
1832 static int tcmu_update_uio_info(struct tcmu_dev *udev)
1834 struct tcmu_hba *hba = udev->hba->hba_ptr;
1835 struct uio_info *info;
1839 info = &udev->uio_info;
1840 size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
1842 size += 1; /* for \0 */
1843 str = kmalloc(size, GFP_KERNEL);
1847 used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
1848 if (udev->dev_config[0])
1849 snprintf(str + used, size - used, "/%s", udev->dev_config);
1851 /* If the old string exists, free it */
1858 static int tcmu_configure_device(struct se_device *dev)
1860 struct tcmu_dev *udev = TCMU_DEV(dev);
1861 struct uio_info *info;
1862 struct tcmu_mailbox *mb;
1865 ret = tcmu_update_uio_info(udev);
1869 info = &udev->uio_info;
1871 mutex_lock(&udev->cmdr_lock);
1872 udev->data_bitmap = kcalloc(BITS_TO_LONGS(udev->max_blocks),
1873 sizeof(unsigned long),
1875 mutex_unlock(&udev->cmdr_lock);
1876 if (!udev->data_bitmap) {
1878 goto err_bitmap_alloc;
1881 udev->mb_addr = vzalloc(CMDR_SIZE);
1882 if (!udev->mb_addr) {
1887 /* mailbox fits in first part of CMDR space */
1888 udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
1889 udev->data_off = CMDR_SIZE;
1890 udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
1891 udev->dbi_thresh = 0; /* Default in Idle state */
1893 /* Initialise the mailbox of the ring buffer */
1895 mb->version = TCMU_MAILBOX_VERSION;
1896 mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC | TCMU_MAILBOX_FLAG_CAP_READ_LEN;
1897 mb->cmdr_off = CMDR_OFF;
1898 mb->cmdr_size = udev->cmdr_size;
1900 WARN_ON(!PAGE_ALIGNED(udev->data_off));
1901 WARN_ON(udev->data_size % PAGE_SIZE);
1902 WARN_ON(udev->data_size % DATA_BLOCK_SIZE);
1904 info->version = __stringify(TCMU_MAILBOX_VERSION);
1906 info->mem[0].name = "tcm-user command & data buffer";
1907 info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
1908 info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
1909 info->mem[0].memtype = UIO_MEM_NONE;
1911 info->irqcontrol = tcmu_irqcontrol;
1912 info->irq = UIO_IRQ_CUSTOM;
1914 info->mmap = tcmu_mmap;
1915 info->open = tcmu_open;
1916 info->release = tcmu_release;
1918 ret = uio_register_device(tcmu_root_device, info);
1922 /* User can set hw_block_size before enable the device */
1923 if (dev->dev_attrib.hw_block_size == 0)
1924 dev->dev_attrib.hw_block_size = 512;
1925 /* Other attributes can be configured in userspace */
1926 if (!dev->dev_attrib.hw_max_sectors)
1927 dev->dev_attrib.hw_max_sectors = 128;
1928 if (!dev->dev_attrib.emulate_write_cache)
1929 dev->dev_attrib.emulate_write_cache = 0;
1930 dev->dev_attrib.hw_queue_depth = 128;
1932 /* If user didn't explicitly disable netlink reply support, use
1933 * module scope setting.
1935 if (udev->nl_reply_supported >= 0)
1936 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
1939 * Get a ref incase userspace does a close on the uio device before
1940 * LIO has initiated tcmu_free_device.
1942 kref_get(&udev->kref);
1944 ret = tcmu_send_dev_add_event(udev);
1948 mutex_lock(&root_udev_mutex);
1949 list_add(&udev->node, &root_udev);
1950 mutex_unlock(&root_udev_mutex);
1955 kref_put(&udev->kref, tcmu_dev_kref_release);
1956 uio_unregister_device(&udev->uio_info);
1958 vfree(udev->mb_addr);
1959 udev->mb_addr = NULL;
1961 kfree(udev->data_bitmap);
1962 udev->data_bitmap = NULL;
1970 static void tcmu_free_device(struct se_device *dev)
1972 struct tcmu_dev *udev = TCMU_DEV(dev);
1974 /* release ref from init */
1975 kref_put(&udev->kref, tcmu_dev_kref_release);
1978 static void tcmu_destroy_device(struct se_device *dev)
1980 struct tcmu_dev *udev = TCMU_DEV(dev);
1982 del_timer_sync(&udev->cmd_timer);
1983 del_timer_sync(&udev->qfull_timer);
1985 mutex_lock(&root_udev_mutex);
1986 list_del(&udev->node);
1987 mutex_unlock(&root_udev_mutex);
1989 tcmu_send_dev_remove_event(udev);
1991 uio_unregister_device(&udev->uio_info);
1993 /* release ref from configure */
1994 kref_put(&udev->kref, tcmu_dev_kref_release);
1997 static void tcmu_unblock_dev(struct tcmu_dev *udev)
1999 mutex_lock(&udev->cmdr_lock);
2000 clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2001 mutex_unlock(&udev->cmdr_lock);
2004 static void tcmu_block_dev(struct tcmu_dev *udev)
2006 mutex_lock(&udev->cmdr_lock);
2008 if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2011 /* complete IO that has executed successfully */
2012 tcmu_handle_completions(udev);
2013 /* fail IO waiting to be queued */
2014 run_qfull_queue(udev, true);
2017 mutex_unlock(&udev->cmdr_lock);
2020 static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2022 struct tcmu_mailbox *mb;
2023 struct tcmu_cmd *cmd;
2026 mutex_lock(&udev->cmdr_lock);
2028 idr_for_each_entry(&udev->commands, cmd, i) {
2029 if (!test_bit(TCMU_CMD_BIT_INFLIGHT, &cmd->flags))
2032 pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
2033 cmd->cmd_id, udev->name,
2034 test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
2036 idr_remove(&udev->commands, i);
2037 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
2038 list_del_init(&cmd->queue_entry);
2039 if (err_level == 1) {
2041 * Userspace was not able to start the
2042 * command or it is retryable.
2044 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2047 target_complete_cmd(cmd->se_cmd,
2048 SAM_STAT_CHECK_CONDITION);
2051 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2056 tcmu_flush_dcache_range(mb, sizeof(*mb));
2057 pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2058 mb->cmd_tail, mb->cmd_head);
2060 udev->cmdr_last_cleaned = 0;
2063 tcmu_flush_dcache_range(mb, sizeof(*mb));
2065 del_timer(&udev->cmd_timer);
2067 mutex_unlock(&udev->cmdr_lock);
2071 Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2072 Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,
2075 static match_table_t tokens = {
2076 {Opt_dev_config, "dev_config=%s"},
2077 {Opt_dev_size, "dev_size=%s"},
2078 {Opt_hw_block_size, "hw_block_size=%d"},
2079 {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2080 {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2081 {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2085 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2089 ret = match_int(arg, &val);
2091 pr_err("match_int() failed for dev attrib. Error %d.\n",
2097 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2105 static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2109 ret = match_int(arg, &val);
2111 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2117 pr_err("Invalid max_data_area %d.\n", val);
2121 mutex_lock(&udev->cmdr_lock);
2122 if (udev->data_bitmap) {
2123 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2128 udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
2129 if (udev->max_blocks > tcmu_global_max_blocks) {
2130 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2131 val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
2132 udev->max_blocks = tcmu_global_max_blocks;
2136 mutex_unlock(&udev->cmdr_lock);
2140 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2141 const char *page, ssize_t count)
2143 struct tcmu_dev *udev = TCMU_DEV(dev);
2144 char *orig, *ptr, *opts;
2145 substring_t args[MAX_OPT_ARGS];
2148 opts = kstrdup(page, GFP_KERNEL);
2154 while ((ptr = strsep(&opts, ",\n")) != NULL) {
2158 token = match_token(ptr, tokens, args);
2160 case Opt_dev_config:
2161 if (match_strlcpy(udev->dev_config, &args[0],
2162 TCMU_CONFIG_LEN) == 0) {
2166 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2169 ret = match_u64(&args[0], &udev->dev_size);
2171 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2174 case Opt_hw_block_size:
2175 ret = tcmu_set_dev_attrib(&args[0],
2176 &(dev->dev_attrib.hw_block_size));
2178 case Opt_hw_max_sectors:
2179 ret = tcmu_set_dev_attrib(&args[0],
2180 &(dev->dev_attrib.hw_max_sectors));
2182 case Opt_nl_reply_supported:
2183 ret = match_int(&args[0], &udev->nl_reply_supported);
2185 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2188 case Opt_max_data_area_mb:
2189 ret = tcmu_set_max_blocks_param(udev, &args[0]);
2200 return (!ret) ? count : ret;
2203 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2205 struct tcmu_dev *udev = TCMU_DEV(dev);
2208 bl = sprintf(b + bl, "Config: %s ",
2209 udev->dev_config[0] ? udev->dev_config : "NULL");
2210 bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2211 bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
2212 TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2217 static sector_t tcmu_get_blocks(struct se_device *dev)
2219 struct tcmu_dev *udev = TCMU_DEV(dev);
2221 return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2222 dev->dev_attrib.block_size);
2225 static sense_reason_t
2226 tcmu_parse_cdb(struct se_cmd *cmd)
2228 return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2231 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2233 struct se_dev_attrib *da = container_of(to_config_group(item),
2234 struct se_dev_attrib, da_group);
2235 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2237 return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2240 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2243 struct se_dev_attrib *da = container_of(to_config_group(item),
2244 struct se_dev_attrib, da_group);
2245 struct tcmu_dev *udev = container_of(da->da_dev,
2246 struct tcmu_dev, se_dev);
2250 if (da->da_dev->export_count) {
2251 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2255 ret = kstrtou32(page, 0, &val);
2259 udev->cmd_time_out = val * MSEC_PER_SEC;
2262 CONFIGFS_ATTR(tcmu_, cmd_time_out);
2264 static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2266 struct se_dev_attrib *da = container_of(to_config_group(item),
2267 struct se_dev_attrib, da_group);
2268 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2270 return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2271 udev->qfull_time_out :
2272 udev->qfull_time_out / MSEC_PER_SEC);
2275 static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2276 const char *page, size_t count)
2278 struct se_dev_attrib *da = container_of(to_config_group(item),
2279 struct se_dev_attrib, da_group);
2280 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2284 ret = kstrtos32(page, 0, &val);
2289 udev->qfull_time_out = val * MSEC_PER_SEC;
2290 } else if (val == -1) {
2291 udev->qfull_time_out = val;
2293 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2298 CONFIGFS_ATTR(tcmu_, qfull_time_out);
2300 static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2302 struct se_dev_attrib *da = container_of(to_config_group(item),
2303 struct se_dev_attrib, da_group);
2304 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2306 return snprintf(page, PAGE_SIZE, "%u\n",
2307 TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2309 CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2311 static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2313 struct se_dev_attrib *da = container_of(to_config_group(item),
2314 struct se_dev_attrib, da_group);
2315 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2317 return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2320 static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2321 const char *reconfig_data)
2323 struct sk_buff *skb = NULL;
2324 void *msg_header = NULL;
2327 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2331 ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2336 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2341 static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2344 struct se_dev_attrib *da = container_of(to_config_group(item),
2345 struct se_dev_attrib, da_group);
2346 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2350 if (!len || len > TCMU_CONFIG_LEN - 1)
2353 /* Check if device has been configured before */
2354 if (target_dev_configured(&udev->se_dev)) {
2355 ret = tcmu_send_dev_config_event(udev, page);
2357 pr_err("Unable to reconfigure device\n");
2360 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2362 ret = tcmu_update_uio_info(udev);
2367 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2371 CONFIGFS_ATTR(tcmu_, dev_config);
2373 static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2375 struct se_dev_attrib *da = container_of(to_config_group(item),
2376 struct se_dev_attrib, da_group);
2377 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2379 return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2382 static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2384 struct sk_buff *skb = NULL;
2385 void *msg_header = NULL;
2388 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2392 ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2393 size, TCMU_ATTR_PAD);
2398 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2402 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2405 struct se_dev_attrib *da = container_of(to_config_group(item),
2406 struct se_dev_attrib, da_group);
2407 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2411 ret = kstrtou64(page, 0, &val);
2415 /* Check if device has been configured before */
2416 if (target_dev_configured(&udev->se_dev)) {
2417 ret = tcmu_send_dev_size_event(udev, val);
2419 pr_err("Unable to reconfigure device\n");
2423 udev->dev_size = val;
2426 CONFIGFS_ATTR(tcmu_, dev_size);
2428 static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2431 struct se_dev_attrib *da = container_of(to_config_group(item),
2432 struct se_dev_attrib, da_group);
2433 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2435 return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2438 static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2439 const char *page, size_t count)
2441 struct se_dev_attrib *da = container_of(to_config_group(item),
2442 struct se_dev_attrib, da_group);
2443 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2447 ret = kstrtos8(page, 0, &val);
2451 udev->nl_reply_supported = val;
2454 CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2456 static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2459 struct se_dev_attrib *da = container_of(to_config_group(item),
2460 struct se_dev_attrib, da_group);
2462 return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2465 static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2467 struct sk_buff *skb = NULL;
2468 void *msg_header = NULL;
2471 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2475 ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2480 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2484 static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2485 const char *page, size_t count)
2487 struct se_dev_attrib *da = container_of(to_config_group(item),
2488 struct se_dev_attrib, da_group);
2489 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2493 ret = kstrtou8(page, 0, &val);
2497 /* Check if device has been configured before */
2498 if (target_dev_configured(&udev->se_dev)) {
2499 ret = tcmu_send_emulate_write_cache(udev, val);
2501 pr_err("Unable to reconfigure device\n");
2506 da->emulate_write_cache = val;
2509 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2511 static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2513 struct se_device *se_dev = container_of(to_config_group(item),
2516 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2518 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2519 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2521 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2524 static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2527 struct se_device *se_dev = container_of(to_config_group(item),
2530 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2534 if (!target_dev_configured(&udev->se_dev)) {
2535 pr_err("Device is not configured.\n");
2539 ret = kstrtou8(page, 0, &val);
2544 pr_err("Invalid block value %d\n", val);
2549 tcmu_unblock_dev(udev);
2551 tcmu_block_dev(udev);
2554 CONFIGFS_ATTR(tcmu_, block_dev);
2556 static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2559 struct se_device *se_dev = container_of(to_config_group(item),
2562 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2566 if (!target_dev_configured(&udev->se_dev)) {
2567 pr_err("Device is not configured.\n");
2571 ret = kstrtou8(page, 0, &val);
2575 if (val != 1 && val != 2) {
2576 pr_err("Invalid reset ring value %d\n", val);
2580 tcmu_reset_ring(udev, val);
2583 CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2585 static struct configfs_attribute *tcmu_attrib_attrs[] = {
2586 &tcmu_attr_cmd_time_out,
2587 &tcmu_attr_qfull_time_out,
2588 &tcmu_attr_max_data_area_mb,
2589 &tcmu_attr_dev_config,
2590 &tcmu_attr_dev_size,
2591 &tcmu_attr_emulate_write_cache,
2592 &tcmu_attr_nl_reply_supported,
2596 static struct configfs_attribute **tcmu_attrs;
2598 static struct configfs_attribute *tcmu_action_attrs[] = {
2599 &tcmu_attr_block_dev,
2600 &tcmu_attr_reset_ring,
2604 static struct target_backend_ops tcmu_ops = {
2606 .owner = THIS_MODULE,
2607 .transport_flags = TRANSPORT_FLAG_PASSTHROUGH,
2608 .attach_hba = tcmu_attach_hba,
2609 .detach_hba = tcmu_detach_hba,
2610 .alloc_device = tcmu_alloc_device,
2611 .configure_device = tcmu_configure_device,
2612 .destroy_device = tcmu_destroy_device,
2613 .free_device = tcmu_free_device,
2614 .parse_cdb = tcmu_parse_cdb,
2615 .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2616 .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2617 .get_device_type = sbc_get_device_type,
2618 .get_blocks = tcmu_get_blocks,
2619 .tb_dev_action_attrs = tcmu_action_attrs,
2622 static void find_free_blocks(void)
2624 struct tcmu_dev *udev;
2626 u32 start, end, block, total_freed = 0;
2628 if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
2631 mutex_lock(&root_udev_mutex);
2632 list_for_each_entry(udev, &root_udev, node) {
2633 mutex_lock(&udev->cmdr_lock);
2635 if (!target_dev_configured(&udev->se_dev)) {
2636 mutex_unlock(&udev->cmdr_lock);
2640 /* Try to complete the finished commands first */
2641 tcmu_handle_completions(udev);
2643 /* Skip the udevs in idle */
2644 if (!udev->dbi_thresh) {
2645 mutex_unlock(&udev->cmdr_lock);
2649 end = udev->dbi_max + 1;
2650 block = find_last_bit(udev->data_bitmap, end);
2651 if (block == udev->dbi_max) {
2653 * The last bit is dbi_max, so it is not possible
2654 * reclaim any blocks.
2656 mutex_unlock(&udev->cmdr_lock);
2658 } else if (block == end) {
2659 /* The current udev will goto idle state */
2660 udev->dbi_thresh = start = 0;
2663 udev->dbi_thresh = start = block + 1;
2664 udev->dbi_max = block;
2667 /* Here will truncate the data area from off */
2668 off = udev->data_off + start * DATA_BLOCK_SIZE;
2669 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
2671 /* Release the block pages */
2672 tcmu_blocks_release(&udev->data_blocks, start, end);
2673 mutex_unlock(&udev->cmdr_lock);
2675 total_freed += end - start;
2676 pr_debug("Freed %u blocks (total %u) from %s.\n", end - start,
2677 total_freed, udev->name);
2679 mutex_unlock(&root_udev_mutex);
2681 if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
2682 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
2685 static void check_timedout_devices(void)
2687 struct tcmu_dev *udev, *tmp_dev;
2690 spin_lock_bh(&timed_out_udevs_lock);
2691 list_splice_init(&timed_out_udevs, &devs);
2693 list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
2694 list_del_init(&udev->timedout_entry);
2695 spin_unlock_bh(&timed_out_udevs_lock);
2697 mutex_lock(&udev->cmdr_lock);
2698 idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
2700 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
2701 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
2703 mutex_unlock(&udev->cmdr_lock);
2705 spin_lock_bh(&timed_out_udevs_lock);
2708 spin_unlock_bh(&timed_out_udevs_lock);
2711 static void tcmu_unmap_work_fn(struct work_struct *work)
2713 check_timedout_devices();
2717 static int __init tcmu_module_init(void)
2719 int ret, i, k, len = 0;
2721 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
2723 INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
2725 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
2726 sizeof(struct tcmu_cmd),
2727 __alignof__(struct tcmu_cmd),
2729 if (!tcmu_cmd_cache)
2732 tcmu_root_device = root_device_register("tcm_user");
2733 if (IS_ERR(tcmu_root_device)) {
2734 ret = PTR_ERR(tcmu_root_device);
2735 goto out_free_cache;
2738 ret = genl_register_family(&tcmu_genl_family);
2740 goto out_unreg_device;
2743 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
2744 len += sizeof(struct configfs_attribute *);
2746 for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) {
2747 len += sizeof(struct configfs_attribute *);
2749 len += sizeof(struct configfs_attribute *);
2751 tcmu_attrs = kzalloc(len, GFP_KERNEL);
2754 goto out_unreg_genl;
2757 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
2758 tcmu_attrs[i] = passthrough_attrib_attrs[i];
2760 for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) {
2761 tcmu_attrs[i] = tcmu_attrib_attrs[k];
2764 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
2766 ret = transport_backend_register(&tcmu_ops);
2775 genl_unregister_family(&tcmu_genl_family);
2777 root_device_unregister(tcmu_root_device);
2779 kmem_cache_destroy(tcmu_cmd_cache);
2784 static void __exit tcmu_module_exit(void)
2786 cancel_delayed_work_sync(&tcmu_unmap_work);
2787 target_backend_unregister(&tcmu_ops);
2789 genl_unregister_family(&tcmu_genl_family);
2790 root_device_unregister(tcmu_root_device);
2791 kmem_cache_destroy(tcmu_cmd_cache);
2794 MODULE_DESCRIPTION("TCM USER subsystem plugin");
2795 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
2796 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
2797 MODULE_LICENSE("GPL");
2799 module_init(tcmu_module_init);
2800 module_exit(tcmu_module_exit);