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(vmalloc_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;
683 struct page *page = NULL;
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) {
691 flush_dcache_page(page);
695 block_remaining = DATA_BLOCK_SIZE;
696 dbi = tcmu_cmd_get_dbi(tcmu_cmd);
697 page = tcmu_get_block_page(udev, dbi);
698 to = kmap_atomic(page);
702 * Covert to virtual offset of the ring data area.
704 to_offset = get_block_offset_user(udev, dbi,
708 * The following code will gather and map the blocks
709 * to the same iovec when the blocks are all next to
712 copy_bytes = min_t(size_t, sg_remaining,
715 to_offset == iov_tail(*iov)) {
717 * Will append to the current iovec, because
718 * the current block page is next to the
721 (*iov)->iov_len += copy_bytes;
724 * Will allocate a new iovec because we are
725 * first time here or the current block page
726 * is not next to the previous one.
728 new_iov(iov, iov_cnt);
729 (*iov)->iov_base = (void __user *)to_offset;
730 (*iov)->iov_len = copy_bytes;
734 offset = DATA_BLOCK_SIZE - block_remaining;
736 from + sg->length - sg_remaining,
740 sg_remaining -= copy_bytes;
741 block_remaining -= copy_bytes;
743 kunmap_atomic(from - sg->offset);
747 flush_dcache_page(page);
752 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
753 bool bidi, uint32_t read_len)
755 struct se_cmd *se_cmd = cmd->se_cmd;
757 int block_remaining = 0;
758 void *from = NULL, *to;
759 size_t copy_bytes, offset;
760 struct scatterlist *sg, *data_sg;
762 unsigned int data_nents;
766 data_sg = se_cmd->t_data_sg;
767 data_nents = se_cmd->t_data_nents;
771 * For bidi case, the first count blocks are for Data-Out
772 * buffer blocks, and before gathering the Data-In buffer
773 * the Data-Out buffer blocks should be discarded.
775 count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
777 data_sg = se_cmd->t_bidi_data_sg;
778 data_nents = se_cmd->t_bidi_data_nents;
781 tcmu_cmd_set_dbi_cur(cmd, count);
783 for_each_sg(data_sg, sg, data_nents, i) {
784 int sg_remaining = sg->length;
785 to = kmap_atomic(sg_page(sg)) + sg->offset;
786 while (sg_remaining > 0 && read_len > 0) {
787 if (block_remaining == 0) {
791 block_remaining = DATA_BLOCK_SIZE;
792 dbi = tcmu_cmd_get_dbi(cmd);
793 page = tcmu_get_block_page(udev, dbi);
794 from = kmap_atomic(page);
795 flush_dcache_page(page);
797 copy_bytes = min_t(size_t, sg_remaining,
799 if (read_len < copy_bytes)
800 copy_bytes = read_len;
801 offset = DATA_BLOCK_SIZE - block_remaining;
802 memcpy(to + sg->length - sg_remaining, from + offset,
805 sg_remaining -= copy_bytes;
806 block_remaining -= copy_bytes;
807 read_len -= copy_bytes;
809 kunmap_atomic(to - sg->offset);
817 static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
819 return thresh - bitmap_weight(bitmap, thresh);
823 * We can't queue a command until we have space available on the cmd ring *and*
824 * space available on the data area.
826 * Called with ring lock held.
828 static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
829 size_t cmd_size, size_t data_needed)
831 struct tcmu_mailbox *mb = udev->mb_addr;
832 uint32_t blocks_needed = (data_needed + DATA_BLOCK_SIZE - 1)
834 size_t space, cmd_needed;
837 tcmu_flush_dcache_range(mb, sizeof(*mb));
839 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
842 * If cmd end-of-ring space is too small then we need space for a NOP plus
843 * original cmd - cmds are internally contiguous.
845 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
846 cmd_needed = cmd_size;
848 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
850 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
851 if (space < cmd_needed) {
852 pr_debug("no cmd space: %u %u %u\n", cmd_head,
853 udev->cmdr_last_cleaned, udev->cmdr_size);
857 /* try to check and get the data blocks as needed */
858 space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
859 if ((space * DATA_BLOCK_SIZE) < data_needed) {
860 unsigned long blocks_left =
861 (udev->max_blocks - udev->dbi_thresh) + space;
863 if (blocks_left < blocks_needed) {
864 pr_debug("no data space: only %lu available, but ask for %zu\n",
865 blocks_left * DATA_BLOCK_SIZE,
870 udev->dbi_thresh += blocks_needed;
871 if (udev->dbi_thresh > udev->max_blocks)
872 udev->dbi_thresh = udev->max_blocks;
875 return tcmu_get_empty_blocks(udev, cmd);
878 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
880 return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
881 sizeof(struct tcmu_cmd_entry));
884 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
885 size_t base_command_size)
887 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
890 command_size = base_command_size +
891 round_up(scsi_command_size(se_cmd->t_task_cdb),
894 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
899 static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
900 struct timer_list *timer)
905 tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
906 if (!timer_pending(timer))
907 mod_timer(timer, tcmu_cmd->deadline);
909 pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
910 tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
913 static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
915 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
919 * For backwards compat if qfull_time_out is not set use
920 * cmd_time_out and if that's not set use the default time out.
922 if (!udev->qfull_time_out)
924 else if (udev->qfull_time_out > 0)
925 tmo = udev->qfull_time_out;
926 else if (udev->cmd_time_out)
927 tmo = udev->cmd_time_out;
931 tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
933 list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
934 pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
935 tcmu_cmd, udev->name);
940 * queue_cmd_ring - queue cmd to ring or internally
941 * @tcmu_cmd: cmd to queue
942 * @scsi_err: TCM error code if failure (-1) returned.
945 * -1 we cannot queue internally or to the ring.
947 * 1 internally queued to wait for ring memory to free.
949 static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
951 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
952 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
953 size_t base_command_size, command_size;
954 struct tcmu_mailbox *mb;
955 struct tcmu_cmd_entry *entry;
960 bool copy_to_data_area;
961 size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
963 *scsi_err = TCM_NO_SENSE;
965 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
966 *scsi_err = TCM_LUN_BUSY;
970 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
971 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
976 * Must be a certain minimum size for response sense info, but
977 * also may be larger if the iov array is large.
979 * We prepare as many iovs as possbile for potential uses here,
980 * because it's expensive to tell how many regions are freed in
981 * the bitmap & global data pool, as the size calculated here
982 * will only be used to do the checks.
984 * The size will be recalculated later as actually needed to save
987 base_command_size = tcmu_cmd_get_base_cmd_size(tcmu_cmd->dbi_cnt);
988 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
990 if (!list_empty(&udev->qfull_queue))
994 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
995 if ((command_size > (udev->cmdr_size / 2)) ||
996 data_length > udev->data_size) {
997 pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
998 "cmd ring/data area\n", command_size, data_length,
999 udev->cmdr_size, udev->data_size);
1000 *scsi_err = TCM_INVALID_CDB_FIELD;
1004 if (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) {
1006 * Don't leave commands partially setup because the unmap
1007 * thread might need the blocks to make forward progress.
1009 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1010 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1014 /* Insert a PAD if end-of-ring space is too small */
1015 if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
1016 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
1018 entry = (void *) mb + CMDR_OFF + cmd_head;
1019 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
1020 tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
1021 entry->hdr.cmd_id = 0; /* not used for PAD */
1022 entry->hdr.kflags = 0;
1023 entry->hdr.uflags = 0;
1024 tcmu_flush_dcache_range(entry, sizeof(entry->hdr));
1026 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
1027 tcmu_flush_dcache_range(mb, sizeof(*mb));
1029 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
1030 WARN_ON(cmd_head != 0);
1033 entry = (void *) mb + CMDR_OFF + cmd_head;
1034 memset(entry, 0, command_size);
1035 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1037 /* Handle allocating space from the data area */
1038 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1039 iov = &entry->req.iov[0];
1041 copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE
1042 || se_cmd->se_cmd_flags & SCF_BIDI);
1043 scatter_data_area(udev, tcmu_cmd, se_cmd->t_data_sg,
1044 se_cmd->t_data_nents, &iov, &iov_cnt,
1046 entry->req.iov_cnt = iov_cnt;
1048 /* Handle BIDI commands */
1050 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1052 scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg,
1053 se_cmd->t_bidi_data_nents, &iov, &iov_cnt,
1056 entry->req.iov_bidi_cnt = iov_cnt;
1058 cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT);
1060 pr_err("tcmu: Could not allocate cmd id.\n");
1062 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1063 *scsi_err = TCM_OUT_OF_RESOURCES;
1066 tcmu_cmd->cmd_id = cmd_id;
1068 pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1069 tcmu_cmd, udev->name);
1071 tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1073 entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1076 * Recalaulate the command's base size and size according
1077 * to the actual needs
1079 base_command_size = tcmu_cmd_get_base_cmd_size(entry->req.iov_cnt +
1080 entry->req.iov_bidi_cnt);
1081 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1083 tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1085 /* All offsets relative to mb_addr, not start of entry! */
1086 cdb_off = CMDR_OFF + cmd_head + base_command_size;
1087 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1088 entry->req.cdb_off = cdb_off;
1089 tcmu_flush_dcache_range(entry, command_size);
1091 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1092 tcmu_flush_dcache_range(mb, sizeof(*mb));
1094 list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1095 set_bit(TCMU_CMD_BIT_INFLIGHT, &tcmu_cmd->flags);
1097 /* TODO: only if FLUSH and FUA? */
1098 uio_event_notify(&udev->uio_info);
1103 if (add_to_qfull_queue(tcmu_cmd)) {
1104 *scsi_err = TCM_OUT_OF_RESOURCES;
1111 static sense_reason_t
1112 tcmu_queue_cmd(struct se_cmd *se_cmd)
1114 struct se_device *se_dev = se_cmd->se_dev;
1115 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1116 struct tcmu_cmd *tcmu_cmd;
1117 sense_reason_t scsi_ret;
1120 tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1122 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1124 mutex_lock(&udev->cmdr_lock);
1125 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1126 mutex_unlock(&udev->cmdr_lock);
1128 tcmu_free_cmd(tcmu_cmd);
1132 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1134 struct se_cmd *se_cmd = cmd->se_cmd;
1135 struct tcmu_dev *udev = cmd->tcmu_dev;
1136 bool read_len_valid = false;
1140 * cmd has been completed already from timeout, just reclaim
1141 * data area space and free cmd
1143 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1144 WARN_ON_ONCE(se_cmd);
1148 list_del_init(&cmd->queue_entry);
1150 tcmu_cmd_reset_dbi_cur(cmd);
1152 if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1153 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1155 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1159 read_len = se_cmd->data_length;
1160 if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1161 (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1162 read_len_valid = true;
1163 if (entry->rsp.read_len < read_len)
1164 read_len = entry->rsp.read_len;
1167 if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1168 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1169 if (!read_len_valid )
1172 se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1174 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1175 /* Get Data-In buffer before clean up */
1176 gather_data_area(udev, cmd, true, read_len);
1177 } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1178 gather_data_area(udev, cmd, false, read_len);
1179 } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1181 } else if (se_cmd->data_direction != DMA_NONE) {
1182 pr_warn("TCMU: data direction was %d!\n",
1183 se_cmd->data_direction);
1187 if (read_len_valid) {
1188 pr_debug("read_len = %d\n", read_len);
1189 target_complete_cmd_with_length(cmd->se_cmd,
1190 entry->rsp.scsi_status, read_len);
1192 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1196 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1200 static void tcmu_set_next_deadline(struct list_head *queue,
1201 struct timer_list *timer)
1203 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1204 unsigned long deadline = 0;
1206 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, queue, queue_entry) {
1207 if (!time_after(jiffies, tcmu_cmd->deadline)) {
1208 deadline = tcmu_cmd->deadline;
1214 mod_timer(timer, deadline);
1219 static bool tcmu_handle_completions(struct tcmu_dev *udev)
1221 struct tcmu_mailbox *mb;
1222 struct tcmu_cmd *cmd;
1225 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1226 pr_err("ring broken, not handling completions\n");
1231 tcmu_flush_dcache_range(mb, sizeof(*mb));
1233 while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1235 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
1238 * Flush max. up to end of cmd ring since current entry might
1239 * be a padding that is shorter than sizeof(*entry)
1241 size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1243 tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1244 ring_left : sizeof(*entry));
1246 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) {
1247 UPDATE_HEAD(udev->cmdr_last_cleaned,
1248 tcmu_hdr_get_len(entry->hdr.len_op),
1252 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1254 cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
1256 pr_err("cmd_id %u not found, ring is broken\n",
1258 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1262 tcmu_handle_completion(cmd, entry);
1264 UPDATE_HEAD(udev->cmdr_last_cleaned,
1265 tcmu_hdr_get_len(entry->hdr.len_op),
1271 if (mb->cmd_tail == mb->cmd_head) {
1272 /* no more pending commands */
1273 del_timer(&udev->cmd_timer);
1275 if (list_empty(&udev->qfull_queue)) {
1277 * no more pending or waiting commands so try to
1278 * reclaim blocks if needed.
1280 if (atomic_read(&global_db_count) >
1281 tcmu_global_max_blocks)
1282 schedule_delayed_work(&tcmu_unmap_work, 0);
1284 } else if (udev->cmd_time_out) {
1285 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1291 static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1293 struct se_cmd *se_cmd;
1295 if (!time_after(jiffies, cmd->deadline))
1298 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1299 list_del_init(&cmd->queue_entry);
1300 se_cmd = cmd->se_cmd;
1303 pr_debug("Timing out inflight cmd %u on dev %s.\n",
1304 cmd->cmd_id, cmd->tcmu_dev->name);
1306 target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1309 static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1311 struct se_cmd *se_cmd;
1313 if (!time_after(jiffies, cmd->deadline))
1316 pr_debug("Timing out queued cmd %p on dev %s.\n",
1317 cmd, cmd->tcmu_dev->name);
1319 list_del_init(&cmd->queue_entry);
1320 se_cmd = cmd->se_cmd;
1323 target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1326 static void tcmu_device_timedout(struct tcmu_dev *udev)
1328 spin_lock(&timed_out_udevs_lock);
1329 if (list_empty(&udev->timedout_entry))
1330 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1331 spin_unlock(&timed_out_udevs_lock);
1333 schedule_delayed_work(&tcmu_unmap_work, 0);
1336 static void tcmu_cmd_timedout(struct timer_list *t)
1338 struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1340 pr_debug("%s cmd timeout has expired\n", udev->name);
1341 tcmu_device_timedout(udev);
1344 static void tcmu_qfull_timedout(struct timer_list *t)
1346 struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1348 pr_debug("%s qfull timeout has expired\n", udev->name);
1349 tcmu_device_timedout(udev);
1352 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1354 struct tcmu_hba *tcmu_hba;
1356 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1360 tcmu_hba->host_id = host_id;
1361 hba->hba_ptr = tcmu_hba;
1366 static void tcmu_detach_hba(struct se_hba *hba)
1368 kfree(hba->hba_ptr);
1369 hba->hba_ptr = NULL;
1372 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1374 struct tcmu_dev *udev;
1376 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1379 kref_init(&udev->kref);
1381 udev->name = kstrdup(name, GFP_KERNEL);
1388 udev->cmd_time_out = TCMU_TIME_OUT;
1389 udev->qfull_time_out = -1;
1391 udev->max_blocks = DATA_BLOCK_BITS_DEF;
1392 mutex_init(&udev->cmdr_lock);
1394 INIT_LIST_HEAD(&udev->node);
1395 INIT_LIST_HEAD(&udev->timedout_entry);
1396 INIT_LIST_HEAD(&udev->qfull_queue);
1397 INIT_LIST_HEAD(&udev->inflight_queue);
1398 idr_init(&udev->commands);
1400 timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1401 timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1403 INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
1405 return &udev->se_dev;
1408 static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1410 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1412 sense_reason_t scsi_ret;
1415 if (list_empty(&udev->qfull_queue))
1418 pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1420 list_splice_init(&udev->qfull_queue, &cmds);
1422 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1423 list_del_init(&tcmu_cmd->queue_entry);
1425 pr_debug("removing cmd %p on dev %s from queue\n",
1426 tcmu_cmd, udev->name);
1430 * We were not able to even start the command, so
1431 * fail with busy to allow a retry in case runner
1432 * was only temporarily down. If the device is being
1433 * removed then LIO core will do the right thing and
1436 target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1437 tcmu_free_cmd(tcmu_cmd);
1441 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1443 pr_debug("cmd %p on dev %s failed with %u\n",
1444 tcmu_cmd, udev->name, scsi_ret);
1446 * Ignore scsi_ret for now. target_complete_cmd
1449 target_complete_cmd(tcmu_cmd->se_cmd,
1450 SAM_STAT_CHECK_CONDITION);
1451 tcmu_free_cmd(tcmu_cmd);
1452 } else if (ret > 0) {
1453 pr_debug("ran out of space during cmdr queue run\n");
1455 * cmd was requeued, so just put all cmds back in
1458 list_splice_tail(&cmds, &udev->qfull_queue);
1463 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1466 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1468 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1470 mutex_lock(&udev->cmdr_lock);
1471 tcmu_handle_completions(udev);
1472 run_qfull_queue(udev, false);
1473 mutex_unlock(&udev->cmdr_lock);
1479 * mmap code from uio.c. Copied here because we want to hook mmap()
1480 * and this stuff must come along.
1482 static int tcmu_find_mem_index(struct vm_area_struct *vma)
1484 struct tcmu_dev *udev = vma->vm_private_data;
1485 struct uio_info *info = &udev->uio_info;
1487 if (vma->vm_pgoff < MAX_UIO_MAPS) {
1488 if (info->mem[vma->vm_pgoff].size == 0)
1490 return (int)vma->vm_pgoff;
1495 static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
1499 mutex_lock(&udev->cmdr_lock);
1500 page = tcmu_get_block_page(udev, dbi);
1503 mutex_unlock(&udev->cmdr_lock);
1508 * Userspace messed up and passed in a address not in the
1509 * data iov passed to it.
1511 pr_err("Invalid addr to data block mapping (dbi %u) on device %s\n",
1514 mutex_unlock(&udev->cmdr_lock);
1519 static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1521 struct tcmu_dev *udev = vmf->vma->vm_private_data;
1522 struct uio_info *info = &udev->uio_info;
1524 unsigned long offset;
1527 int mi = tcmu_find_mem_index(vmf->vma);
1529 return VM_FAULT_SIGBUS;
1532 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1535 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1537 if (offset < udev->data_off) {
1538 /* For the vmalloc()ed cmd area pages */
1539 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1540 page = vmalloc_to_page(addr);
1545 /* For the dynamically growing data area pages */
1546 dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
1547 page = tcmu_try_get_block_page(udev, dbi);
1549 return VM_FAULT_SIGBUS;
1556 static const struct vm_operations_struct tcmu_vm_ops = {
1557 .fault = tcmu_vma_fault,
1560 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1562 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1564 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1565 vma->vm_ops = &tcmu_vm_ops;
1567 vma->vm_private_data = udev;
1569 /* Ensure the mmap is exactly the right size */
1570 if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
1576 static int tcmu_open(struct uio_info *info, struct inode *inode)
1578 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1580 /* O_EXCL not supported for char devs, so fake it? */
1581 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1584 udev->inode = inode;
1585 kref_get(&udev->kref);
1592 static void tcmu_dev_call_rcu(struct rcu_head *p)
1594 struct se_device *dev = container_of(p, struct se_device, rcu_head);
1595 struct tcmu_dev *udev = TCMU_DEV(dev);
1597 kfree(udev->uio_info.name);
1602 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1604 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1605 kmem_cache_free(tcmu_cmd_cache, cmd);
1611 static void tcmu_blocks_release(struct radix_tree_root *blocks,
1617 for (i = start; i < end; i++) {
1618 page = radix_tree_delete(blocks, i);
1621 atomic_dec(&global_db_count);
1626 static void tcmu_dev_kref_release(struct kref *kref)
1628 struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1629 struct se_device *dev = &udev->se_dev;
1630 struct tcmu_cmd *cmd;
1631 bool all_expired = true;
1634 vfree(udev->mb_addr);
1635 udev->mb_addr = NULL;
1637 spin_lock_bh(&timed_out_udevs_lock);
1638 if (!list_empty(&udev->timedout_entry))
1639 list_del(&udev->timedout_entry);
1640 spin_unlock_bh(&timed_out_udevs_lock);
1642 /* Upper layer should drain all requests before calling this */
1643 mutex_lock(&udev->cmdr_lock);
1644 idr_for_each_entry(&udev->commands, cmd, i) {
1645 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1646 all_expired = false;
1648 if (!list_empty(&udev->qfull_queue))
1649 all_expired = false;
1650 idr_destroy(&udev->commands);
1651 WARN_ON(!all_expired);
1653 tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
1654 kfree(udev->data_bitmap);
1655 mutex_unlock(&udev->cmdr_lock);
1657 call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1660 static int tcmu_release(struct uio_info *info, struct inode *inode)
1662 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1664 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1666 pr_debug("close\n");
1667 /* release ref from open */
1668 kref_put(&udev->kref, tcmu_dev_kref_release);
1672 static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1674 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1676 if (!tcmu_kern_cmd_reply_supported)
1679 if (udev->nl_reply_supported <= 0)
1682 mutex_lock(&tcmu_nl_cmd_mutex);
1684 if (tcmu_netlink_blocked) {
1685 mutex_unlock(&tcmu_nl_cmd_mutex);
1686 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1691 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1692 mutex_unlock(&tcmu_nl_cmd_mutex);
1693 pr_warn("netlink cmd %d already executing on %s\n",
1694 nl_cmd->cmd, udev->name);
1698 memset(nl_cmd, 0, sizeof(*nl_cmd));
1700 nl_cmd->udev = udev;
1701 init_completion(&nl_cmd->complete);
1702 INIT_LIST_HEAD(&nl_cmd->nl_list);
1704 list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
1706 mutex_unlock(&tcmu_nl_cmd_mutex);
1710 static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1712 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1715 if (!tcmu_kern_cmd_reply_supported)
1718 if (udev->nl_reply_supported <= 0)
1721 pr_debug("sleeping for nl reply\n");
1722 wait_for_completion(&nl_cmd->complete);
1724 mutex_lock(&tcmu_nl_cmd_mutex);
1725 nl_cmd->cmd = TCMU_CMD_UNSPEC;
1726 ret = nl_cmd->status;
1727 mutex_unlock(&tcmu_nl_cmd_mutex);
1732 static int tcmu_netlink_event_init(struct tcmu_dev *udev,
1733 enum tcmu_genl_cmd cmd,
1734 struct sk_buff **buf, void **hdr)
1736 struct sk_buff *skb;
1740 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1744 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
1748 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
1752 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
1756 ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
1769 static int tcmu_netlink_event_send(struct tcmu_dev *udev,
1770 enum tcmu_genl_cmd cmd,
1771 struct sk_buff *skb, void *msg_header)
1775 genlmsg_end(skb, msg_header);
1777 ret = tcmu_init_genl_cmd_reply(udev, cmd);
1783 ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
1784 TCMU_MCGRP_CONFIG, GFP_KERNEL);
1785 /* We don't care if no one is listening */
1789 ret = tcmu_wait_genl_cmd_reply(udev);
1793 static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
1795 struct sk_buff *skb = NULL;
1796 void *msg_header = NULL;
1799 ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
1803 return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
1807 static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
1809 struct sk_buff *skb = NULL;
1810 void *msg_header = NULL;
1813 ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
1817 return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
1821 static int tcmu_update_uio_info(struct tcmu_dev *udev)
1823 struct tcmu_hba *hba = udev->hba->hba_ptr;
1824 struct uio_info *info;
1828 info = &udev->uio_info;
1829 size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
1831 size += 1; /* for \0 */
1832 str = kmalloc(size, GFP_KERNEL);
1836 used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
1837 if (udev->dev_config[0])
1838 snprintf(str + used, size - used, "/%s", udev->dev_config);
1840 /* If the old string exists, free it */
1847 static int tcmu_configure_device(struct se_device *dev)
1849 struct tcmu_dev *udev = TCMU_DEV(dev);
1850 struct uio_info *info;
1851 struct tcmu_mailbox *mb;
1854 ret = tcmu_update_uio_info(udev);
1858 info = &udev->uio_info;
1860 mutex_lock(&udev->cmdr_lock);
1861 udev->data_bitmap = kcalloc(BITS_TO_LONGS(udev->max_blocks),
1862 sizeof(unsigned long),
1864 mutex_unlock(&udev->cmdr_lock);
1865 if (!udev->data_bitmap) {
1867 goto err_bitmap_alloc;
1870 udev->mb_addr = vzalloc(CMDR_SIZE);
1871 if (!udev->mb_addr) {
1876 /* mailbox fits in first part of CMDR space */
1877 udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
1878 udev->data_off = CMDR_SIZE;
1879 udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
1880 udev->dbi_thresh = 0; /* Default in Idle state */
1882 /* Initialise the mailbox of the ring buffer */
1884 mb->version = TCMU_MAILBOX_VERSION;
1885 mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC | TCMU_MAILBOX_FLAG_CAP_READ_LEN;
1886 mb->cmdr_off = CMDR_OFF;
1887 mb->cmdr_size = udev->cmdr_size;
1889 WARN_ON(!PAGE_ALIGNED(udev->data_off));
1890 WARN_ON(udev->data_size % PAGE_SIZE);
1891 WARN_ON(udev->data_size % DATA_BLOCK_SIZE);
1893 info->version = __stringify(TCMU_MAILBOX_VERSION);
1895 info->mem[0].name = "tcm-user command & data buffer";
1896 info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
1897 info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
1898 info->mem[0].memtype = UIO_MEM_NONE;
1900 info->irqcontrol = tcmu_irqcontrol;
1901 info->irq = UIO_IRQ_CUSTOM;
1903 info->mmap = tcmu_mmap;
1904 info->open = tcmu_open;
1905 info->release = tcmu_release;
1907 ret = uio_register_device(tcmu_root_device, info);
1911 /* User can set hw_block_size before enable the device */
1912 if (dev->dev_attrib.hw_block_size == 0)
1913 dev->dev_attrib.hw_block_size = 512;
1914 /* Other attributes can be configured in userspace */
1915 if (!dev->dev_attrib.hw_max_sectors)
1916 dev->dev_attrib.hw_max_sectors = 128;
1917 if (!dev->dev_attrib.emulate_write_cache)
1918 dev->dev_attrib.emulate_write_cache = 0;
1919 dev->dev_attrib.hw_queue_depth = 128;
1921 /* If user didn't explicitly disable netlink reply support, use
1922 * module scope setting.
1924 if (udev->nl_reply_supported >= 0)
1925 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
1928 * Get a ref incase userspace does a close on the uio device before
1929 * LIO has initiated tcmu_free_device.
1931 kref_get(&udev->kref);
1933 ret = tcmu_send_dev_add_event(udev);
1937 mutex_lock(&root_udev_mutex);
1938 list_add(&udev->node, &root_udev);
1939 mutex_unlock(&root_udev_mutex);
1944 kref_put(&udev->kref, tcmu_dev_kref_release);
1945 uio_unregister_device(&udev->uio_info);
1947 vfree(udev->mb_addr);
1948 udev->mb_addr = NULL;
1950 kfree(udev->data_bitmap);
1951 udev->data_bitmap = NULL;
1959 static void tcmu_free_device(struct se_device *dev)
1961 struct tcmu_dev *udev = TCMU_DEV(dev);
1963 /* release ref from init */
1964 kref_put(&udev->kref, tcmu_dev_kref_release);
1967 static void tcmu_destroy_device(struct se_device *dev)
1969 struct tcmu_dev *udev = TCMU_DEV(dev);
1971 del_timer_sync(&udev->cmd_timer);
1972 del_timer_sync(&udev->qfull_timer);
1974 mutex_lock(&root_udev_mutex);
1975 list_del(&udev->node);
1976 mutex_unlock(&root_udev_mutex);
1978 tcmu_send_dev_remove_event(udev);
1980 uio_unregister_device(&udev->uio_info);
1982 /* release ref from configure */
1983 kref_put(&udev->kref, tcmu_dev_kref_release);
1986 static void tcmu_unblock_dev(struct tcmu_dev *udev)
1988 mutex_lock(&udev->cmdr_lock);
1989 clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
1990 mutex_unlock(&udev->cmdr_lock);
1993 static void tcmu_block_dev(struct tcmu_dev *udev)
1995 mutex_lock(&udev->cmdr_lock);
1997 if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2000 /* complete IO that has executed successfully */
2001 tcmu_handle_completions(udev);
2002 /* fail IO waiting to be queued */
2003 run_qfull_queue(udev, true);
2006 mutex_unlock(&udev->cmdr_lock);
2009 static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2011 struct tcmu_mailbox *mb;
2012 struct tcmu_cmd *cmd;
2015 mutex_lock(&udev->cmdr_lock);
2017 idr_for_each_entry(&udev->commands, cmd, i) {
2018 pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
2019 cmd->cmd_id, udev->name,
2020 test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
2022 idr_remove(&udev->commands, i);
2023 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
2024 WARN_ON(!cmd->se_cmd);
2025 list_del_init(&cmd->queue_entry);
2026 if (err_level == 1) {
2028 * Userspace was not able to start the
2029 * command or it is retryable.
2031 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2034 target_complete_cmd(cmd->se_cmd,
2035 SAM_STAT_CHECK_CONDITION);
2038 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2043 tcmu_flush_dcache_range(mb, sizeof(*mb));
2044 pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2045 mb->cmd_tail, mb->cmd_head);
2047 udev->cmdr_last_cleaned = 0;
2050 tcmu_flush_dcache_range(mb, sizeof(*mb));
2051 clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2053 del_timer(&udev->cmd_timer);
2055 run_qfull_queue(udev, false);
2057 mutex_unlock(&udev->cmdr_lock);
2061 Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2062 Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,
2065 static match_table_t tokens = {
2066 {Opt_dev_config, "dev_config=%s"},
2067 {Opt_dev_size, "dev_size=%s"},
2068 {Opt_hw_block_size, "hw_block_size=%d"},
2069 {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2070 {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2071 {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2075 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2079 ret = match_int(arg, &val);
2081 pr_err("match_int() failed for dev attrib. Error %d.\n",
2087 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2095 static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2099 ret = match_int(arg, &val);
2101 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2107 pr_err("Invalid max_data_area %d.\n", val);
2111 mutex_lock(&udev->cmdr_lock);
2112 if (udev->data_bitmap) {
2113 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2118 udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
2119 if (udev->max_blocks > tcmu_global_max_blocks) {
2120 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2121 val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
2122 udev->max_blocks = tcmu_global_max_blocks;
2126 mutex_unlock(&udev->cmdr_lock);
2130 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2131 const char *page, ssize_t count)
2133 struct tcmu_dev *udev = TCMU_DEV(dev);
2134 char *orig, *ptr, *opts;
2135 substring_t args[MAX_OPT_ARGS];
2138 opts = kstrdup(page, GFP_KERNEL);
2144 while ((ptr = strsep(&opts, ",\n")) != NULL) {
2148 token = match_token(ptr, tokens, args);
2150 case Opt_dev_config:
2151 if (match_strlcpy(udev->dev_config, &args[0],
2152 TCMU_CONFIG_LEN) == 0) {
2156 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2159 ret = match_u64(&args[0], &udev->dev_size);
2161 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2164 case Opt_hw_block_size:
2165 ret = tcmu_set_dev_attrib(&args[0],
2166 &(dev->dev_attrib.hw_block_size));
2168 case Opt_hw_max_sectors:
2169 ret = tcmu_set_dev_attrib(&args[0],
2170 &(dev->dev_attrib.hw_max_sectors));
2172 case Opt_nl_reply_supported:
2173 ret = match_int(&args[0], &udev->nl_reply_supported);
2175 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2178 case Opt_max_data_area_mb:
2179 ret = tcmu_set_max_blocks_param(udev, &args[0]);
2190 return (!ret) ? count : ret;
2193 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2195 struct tcmu_dev *udev = TCMU_DEV(dev);
2198 bl = sprintf(b + bl, "Config: %s ",
2199 udev->dev_config[0] ? udev->dev_config : "NULL");
2200 bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2201 bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
2202 TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2207 static sector_t tcmu_get_blocks(struct se_device *dev)
2209 struct tcmu_dev *udev = TCMU_DEV(dev);
2211 return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2212 dev->dev_attrib.block_size);
2215 static sense_reason_t
2216 tcmu_parse_cdb(struct se_cmd *cmd)
2218 return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2221 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2223 struct se_dev_attrib *da = container_of(to_config_group(item),
2224 struct se_dev_attrib, da_group);
2225 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2227 return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2230 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const 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 = container_of(da->da_dev,
2236 struct tcmu_dev, se_dev);
2240 if (da->da_dev->export_count) {
2241 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2245 ret = kstrtou32(page, 0, &val);
2249 udev->cmd_time_out = val * MSEC_PER_SEC;
2252 CONFIGFS_ATTR(tcmu_, cmd_time_out);
2254 static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2256 struct se_dev_attrib *da = container_of(to_config_group(item),
2257 struct se_dev_attrib, da_group);
2258 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2260 return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2261 udev->qfull_time_out :
2262 udev->qfull_time_out / MSEC_PER_SEC);
2265 static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2266 const char *page, size_t count)
2268 struct se_dev_attrib *da = container_of(to_config_group(item),
2269 struct se_dev_attrib, da_group);
2270 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2274 ret = kstrtos32(page, 0, &val);
2279 udev->qfull_time_out = val * MSEC_PER_SEC;
2280 } else if (val == -1) {
2281 udev->qfull_time_out = val;
2283 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2288 CONFIGFS_ATTR(tcmu_, qfull_time_out);
2290 static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2292 struct se_dev_attrib *da = container_of(to_config_group(item),
2293 struct se_dev_attrib, da_group);
2294 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2296 return snprintf(page, PAGE_SIZE, "%u\n",
2297 TCMU_BLOCKS_TO_MBS(udev->max_blocks));
2299 CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2301 static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2303 struct se_dev_attrib *da = container_of(to_config_group(item),
2304 struct se_dev_attrib, da_group);
2305 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2307 return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2310 static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2311 const char *reconfig_data)
2313 struct sk_buff *skb = NULL;
2314 void *msg_header = NULL;
2317 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2321 ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2326 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2331 static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2334 struct se_dev_attrib *da = container_of(to_config_group(item),
2335 struct se_dev_attrib, da_group);
2336 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2340 if (!len || len > TCMU_CONFIG_LEN - 1)
2343 /* Check if device has been configured before */
2344 if (target_dev_configured(&udev->se_dev)) {
2345 ret = tcmu_send_dev_config_event(udev, page);
2347 pr_err("Unable to reconfigure device\n");
2350 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2352 ret = tcmu_update_uio_info(udev);
2357 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2361 CONFIGFS_ATTR(tcmu_, dev_config);
2363 static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2365 struct se_dev_attrib *da = container_of(to_config_group(item),
2366 struct se_dev_attrib, da_group);
2367 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2369 return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2372 static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2374 struct sk_buff *skb = NULL;
2375 void *msg_header = NULL;
2378 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2382 ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2383 size, TCMU_ATTR_PAD);
2388 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2392 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2395 struct se_dev_attrib *da = container_of(to_config_group(item),
2396 struct se_dev_attrib, da_group);
2397 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2401 ret = kstrtou64(page, 0, &val);
2405 /* Check if device has been configured before */
2406 if (target_dev_configured(&udev->se_dev)) {
2407 ret = tcmu_send_dev_size_event(udev, val);
2409 pr_err("Unable to reconfigure device\n");
2413 udev->dev_size = val;
2416 CONFIGFS_ATTR(tcmu_, dev_size);
2418 static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2421 struct se_dev_attrib *da = container_of(to_config_group(item),
2422 struct se_dev_attrib, da_group);
2423 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2425 return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2428 static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2429 const char *page, size_t count)
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);
2437 ret = kstrtos8(page, 0, &val);
2441 udev->nl_reply_supported = val;
2444 CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2446 static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2449 struct se_dev_attrib *da = container_of(to_config_group(item),
2450 struct se_dev_attrib, da_group);
2452 return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2455 static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2457 struct sk_buff *skb = NULL;
2458 void *msg_header = NULL;
2461 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2465 ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2470 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2474 static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2475 const char *page, size_t count)
2477 struct se_dev_attrib *da = container_of(to_config_group(item),
2478 struct se_dev_attrib, da_group);
2479 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2483 ret = kstrtou8(page, 0, &val);
2487 /* Check if device has been configured before */
2488 if (target_dev_configured(&udev->se_dev)) {
2489 ret = tcmu_send_emulate_write_cache(udev, val);
2491 pr_err("Unable to reconfigure device\n");
2496 da->emulate_write_cache = val;
2499 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2501 static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2503 struct se_device *se_dev = container_of(to_config_group(item),
2506 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2508 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2509 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2511 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2514 static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2517 struct se_device *se_dev = container_of(to_config_group(item),
2520 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2524 if (!target_dev_configured(&udev->se_dev)) {
2525 pr_err("Device is not configured.\n");
2529 ret = kstrtou8(page, 0, &val);
2534 pr_err("Invalid block value %d\n", val);
2539 tcmu_unblock_dev(udev);
2541 tcmu_block_dev(udev);
2544 CONFIGFS_ATTR(tcmu_, block_dev);
2546 static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2549 struct se_device *se_dev = container_of(to_config_group(item),
2552 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2556 if (!target_dev_configured(&udev->se_dev)) {
2557 pr_err("Device is not configured.\n");
2561 ret = kstrtou8(page, 0, &val);
2565 if (val != 1 && val != 2) {
2566 pr_err("Invalid reset ring value %d\n", val);
2570 tcmu_reset_ring(udev, val);
2573 CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2575 static struct configfs_attribute *tcmu_attrib_attrs[] = {
2576 &tcmu_attr_cmd_time_out,
2577 &tcmu_attr_qfull_time_out,
2578 &tcmu_attr_max_data_area_mb,
2579 &tcmu_attr_dev_config,
2580 &tcmu_attr_dev_size,
2581 &tcmu_attr_emulate_write_cache,
2582 &tcmu_attr_nl_reply_supported,
2586 static struct configfs_attribute **tcmu_attrs;
2588 static struct configfs_attribute *tcmu_action_attrs[] = {
2589 &tcmu_attr_block_dev,
2590 &tcmu_attr_reset_ring,
2594 static struct target_backend_ops tcmu_ops = {
2596 .owner = THIS_MODULE,
2597 .transport_flags = TRANSPORT_FLAG_PASSTHROUGH,
2598 .attach_hba = tcmu_attach_hba,
2599 .detach_hba = tcmu_detach_hba,
2600 .alloc_device = tcmu_alloc_device,
2601 .configure_device = tcmu_configure_device,
2602 .destroy_device = tcmu_destroy_device,
2603 .free_device = tcmu_free_device,
2604 .parse_cdb = tcmu_parse_cdb,
2605 .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2606 .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2607 .get_device_type = sbc_get_device_type,
2608 .get_blocks = tcmu_get_blocks,
2609 .tb_dev_action_attrs = tcmu_action_attrs,
2612 static void find_free_blocks(void)
2614 struct tcmu_dev *udev;
2616 u32 start, end, block, total_freed = 0;
2618 if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
2621 mutex_lock(&root_udev_mutex);
2622 list_for_each_entry(udev, &root_udev, node) {
2623 mutex_lock(&udev->cmdr_lock);
2625 if (!target_dev_configured(&udev->se_dev)) {
2626 mutex_unlock(&udev->cmdr_lock);
2630 /* Try to complete the finished commands first */
2631 tcmu_handle_completions(udev);
2633 /* Skip the udevs in idle */
2634 if (!udev->dbi_thresh) {
2635 mutex_unlock(&udev->cmdr_lock);
2639 end = udev->dbi_max + 1;
2640 block = find_last_bit(udev->data_bitmap, end);
2641 if (block == udev->dbi_max) {
2643 * The last bit is dbi_max, so it is not possible
2644 * reclaim any blocks.
2646 mutex_unlock(&udev->cmdr_lock);
2648 } else if (block == end) {
2649 /* The current udev will goto idle state */
2650 udev->dbi_thresh = start = 0;
2653 udev->dbi_thresh = start = block + 1;
2654 udev->dbi_max = block;
2657 /* Here will truncate the data area from off */
2658 off = udev->data_off + start * DATA_BLOCK_SIZE;
2659 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
2661 /* Release the block pages */
2662 tcmu_blocks_release(&udev->data_blocks, start, end);
2663 mutex_unlock(&udev->cmdr_lock);
2665 total_freed += end - start;
2666 pr_debug("Freed %u blocks (total %u) from %s.\n", end - start,
2667 total_freed, udev->name);
2669 mutex_unlock(&root_udev_mutex);
2671 if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
2672 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
2675 static void check_timedout_devices(void)
2677 struct tcmu_dev *udev, *tmp_dev;
2678 struct tcmu_cmd *cmd, *tmp_cmd;
2681 spin_lock_bh(&timed_out_udevs_lock);
2682 list_splice_init(&timed_out_udevs, &devs);
2684 list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
2685 list_del_init(&udev->timedout_entry);
2686 spin_unlock_bh(&timed_out_udevs_lock);
2688 mutex_lock(&udev->cmdr_lock);
2691 * If cmd_time_out is disabled but qfull is set deadline
2692 * will only reflect the qfull timeout. Ignore it.
2694 if (udev->cmd_time_out) {
2695 list_for_each_entry_safe(cmd, tmp_cmd,
2696 &udev->inflight_queue,
2698 tcmu_check_expired_ring_cmd(cmd);
2700 tcmu_set_next_deadline(&udev->inflight_queue,
2703 list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
2705 tcmu_check_expired_queue_cmd(cmd);
2707 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
2709 mutex_unlock(&udev->cmdr_lock);
2711 spin_lock_bh(&timed_out_udevs_lock);
2714 spin_unlock_bh(&timed_out_udevs_lock);
2717 static void tcmu_unmap_work_fn(struct work_struct *work)
2719 check_timedout_devices();
2723 static int __init tcmu_module_init(void)
2725 int ret, i, k, len = 0;
2727 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
2729 INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
2731 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
2732 sizeof(struct tcmu_cmd),
2733 __alignof__(struct tcmu_cmd),
2735 if (!tcmu_cmd_cache)
2738 tcmu_root_device = root_device_register("tcm_user");
2739 if (IS_ERR(tcmu_root_device)) {
2740 ret = PTR_ERR(tcmu_root_device);
2741 goto out_free_cache;
2744 ret = genl_register_family(&tcmu_genl_family);
2746 goto out_unreg_device;
2749 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
2750 len += sizeof(struct configfs_attribute *);
2752 for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) {
2753 len += sizeof(struct configfs_attribute *);
2755 len += sizeof(struct configfs_attribute *);
2757 tcmu_attrs = kzalloc(len, GFP_KERNEL);
2760 goto out_unreg_genl;
2763 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
2764 tcmu_attrs[i] = passthrough_attrib_attrs[i];
2766 for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) {
2767 tcmu_attrs[i] = tcmu_attrib_attrs[k];
2770 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
2772 ret = transport_backend_register(&tcmu_ops);
2781 genl_unregister_family(&tcmu_genl_family);
2783 root_device_unregister(tcmu_root_device);
2785 kmem_cache_destroy(tcmu_cmd_cache);
2790 static void __exit tcmu_module_exit(void)
2792 cancel_delayed_work_sync(&tcmu_unmap_work);
2793 target_backend_unregister(&tcmu_ops);
2795 genl_unregister_family(&tcmu_genl_family);
2796 root_device_unregister(tcmu_root_device);
2797 kmem_cache_destroy(tcmu_cmd_cache);
2800 MODULE_DESCRIPTION("TCM USER subsystem plugin");
2801 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
2802 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
2803 MODULE_LICENSE("GPL");
2805 module_init(tcmu_module_init);
2806 module_exit(tcmu_module_exit);