2 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
3 * Copyright (C) 2014 Red Hat, Inc.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 #include <linux/spinlock.h>
20 #include <linux/module.h>
21 #include <linux/idr.h>
22 #include <linux/timer.h>
23 #include <linux/parser.h>
24 #include <scsi/scsi.h>
25 #include <scsi/scsi_host.h>
26 #include <linux/uio_driver.h>
27 #include <net/genetlink.h>
28 #include <target/target_core_base.h>
29 #include <target/target_core_fabric.h>
30 #include <target/target_core_backend.h>
31 #include <target/target_core_backend_configfs.h>
33 #include <linux/target_core_user.h>
36 * Define a shared-memory interface for LIO to pass SCSI commands and
37 * data to userspace for processing. This is to allow backends that
38 * are too complex for in-kernel support to be possible.
40 * It uses the UIO framework to do a lot of the device-creation and
41 * introspection work for us.
43 * See the .h file for how the ring is laid out. Note that while the
44 * command ring is defined, the particulars of the data area are
45 * not. Offset values in the command entry point to other locations
46 * internal to the mmap()ed area. There is separate space outside the
47 * command ring for data buffers. This leaves maximum flexibility for
48 * moving buffer allocations, or even page flipping or other
49 * allocation techniques, without altering the command ring layout.
52 * The user process must be assumed to be malicious. There's no way to
53 * prevent it breaking the command ring protocol if it wants, but in
54 * order to prevent other issues we must only ever read *data* from
55 * the shared memory area, not offsets or sizes. This applies to
56 * command ring entries as well as the mailbox. Extra code needed for
57 * this may have a 'UAM' comment.
61 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
63 #define CMDR_SIZE (16 * 4096)
64 #define DATA_SIZE (257 * 4096)
66 #define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
68 static struct device *tcmu_root_device;
74 /* User wants all cmds or just some */
81 #define TCMU_CONFIG_LEN 256
84 struct se_device se_dev;
89 #define TCMU_DEV_BIT_OPEN 0
90 #define TCMU_DEV_BIT_BROKEN 1
92 enum passthru_level pass_level;
94 struct uio_info uio_info;
96 struct tcmu_mailbox *mb_addr;
99 u32 cmdr_last_cleaned;
100 /* Offset of data ring from start of mb */
103 /* Ring head + tail values. */
104 /* Must add data_off and mb_addr to get the address */
108 wait_queue_head_t wait_cmdr;
109 /* TODO should this be a mutex? */
110 spinlock_t cmdr_lock;
113 spinlock_t commands_lock;
115 struct timer_list timeout;
117 char dev_config[TCMU_CONFIG_LEN];
120 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
122 #define CMDR_OFF sizeof(struct tcmu_mailbox)
125 struct se_cmd *se_cmd;
126 struct tcmu_dev *tcmu_dev;
130 /* Can't use se_cmd->data_length when cleaning up expired cmds, because if
131 cmd has been completed then accessing se_cmd is off limits */
134 unsigned long deadline;
136 #define TCMU_CMD_BIT_EXPIRED 0
140 static struct kmem_cache *tcmu_cmd_cache;
142 /* multicast group */
143 enum tcmu_multicast_groups {
147 static const struct genl_multicast_group tcmu_mcgrps[] = {
148 [TCMU_MCGRP_CONFIG] = { .name = "config", },
151 /* Our generic netlink family */
152 static struct genl_family tcmu_genl_family = {
153 .id = GENL_ID_GENERATE,
157 .maxattr = TCMU_ATTR_MAX,
158 .mcgrps = tcmu_mcgrps,
159 .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
162 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
164 struct se_device *se_dev = se_cmd->se_dev;
165 struct tcmu_dev *udev = TCMU_DEV(se_dev);
166 struct tcmu_cmd *tcmu_cmd;
169 tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL);
173 tcmu_cmd->se_cmd = se_cmd;
174 tcmu_cmd->tcmu_dev = udev;
175 tcmu_cmd->data_length = se_cmd->data_length;
177 tcmu_cmd->deadline = jiffies + msecs_to_jiffies(TCMU_TIME_OUT);
179 idr_preload(GFP_KERNEL);
180 spin_lock_irq(&udev->commands_lock);
181 cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 0,
182 USHRT_MAX, GFP_NOWAIT);
183 spin_unlock_irq(&udev->commands_lock);
187 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
190 tcmu_cmd->cmd_id = cmd_id;
195 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
197 unsigned long offset = (unsigned long) vaddr & ~PAGE_MASK;
199 size = round_up(size+offset, PAGE_SIZE);
203 flush_dcache_page(virt_to_page(vaddr));
209 * Some ring helper functions. We don't assume size is a power of 2 so
210 * we can't use circ_buf.h.
212 static inline size_t spc_used(size_t head, size_t tail, size_t size)
214 int diff = head - tail;
222 static inline size_t spc_free(size_t head, size_t tail, size_t size)
224 /* Keep 1 byte unused or we can't tell full from empty */
225 return (size - spc_used(head, tail, size) - 1);
228 static inline size_t head_to_end(size_t head, size_t size)
233 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
236 * We can't queue a command until we have space available on the cmd ring *and* space
237 * space avail on the data ring.
239 * Called with ring lock held.
241 static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t data_needed)
243 struct tcmu_mailbox *mb = udev->mb_addr;
248 tcmu_flush_dcache_range(mb, sizeof(*mb));
250 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
253 * If cmd end-of-ring space is too small then we need space for a NOP plus
254 * original cmd - cmds are internally contiguous.
256 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
257 cmd_needed = cmd_size;
259 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
261 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
262 if (space < cmd_needed) {
263 pr_debug("no cmd space: %u %u %u\n", cmd_head,
264 udev->cmdr_last_cleaned, udev->cmdr_size);
268 space = spc_free(udev->data_head, udev->data_tail, udev->data_size);
269 if (space < data_needed) {
270 pr_debug("no data space: %zu %zu %zu\n", udev->data_head,
271 udev->data_tail, udev->data_size);
278 static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
280 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
281 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
282 size_t base_command_size, command_size;
283 struct tcmu_mailbox *mb;
284 struct tcmu_cmd_entry *entry;
286 struct scatterlist *sg;
292 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
296 * Must be a certain minimum size for response sense info, but
297 * also may be larger if the iov array is large.
299 * iovs = sgl_nents+1, for end-of-ring case, plus another 1
300 * b/c size == offsetof one-past-element.
302 base_command_size = max(offsetof(struct tcmu_cmd_entry,
303 req.iov[se_cmd->t_data_nents + 2]),
304 sizeof(struct tcmu_cmd_entry));
305 command_size = base_command_size
306 + round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE);
308 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
310 spin_lock_irq(&udev->cmdr_lock);
313 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
314 if ((command_size > (udev->cmdr_size / 2))
315 || tcmu_cmd->data_length > (udev->data_size - 1))
316 pr_warn("TCMU: Request of size %zu/%zu may be too big for %u/%zu "
317 "cmd/data ring buffers\n", command_size, tcmu_cmd->data_length,
318 udev->cmdr_size, udev->data_size);
320 while (!is_ring_space_avail(udev, command_size, tcmu_cmd->data_length)) {
324 prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE);
326 pr_debug("sleeping for ring space\n");
327 spin_unlock_irq(&udev->cmdr_lock);
328 ret = schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT));
329 finish_wait(&udev->wait_cmdr, &__wait);
331 pr_warn("tcmu: command timed out\n");
335 spin_lock_irq(&udev->cmdr_lock);
337 /* We dropped cmdr_lock, cmd_head is stale */
338 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
341 /* Insert a PAD if end-of-ring space is too small */
342 if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
343 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
345 entry = (void *) mb + CMDR_OFF + cmd_head;
346 tcmu_flush_dcache_range(entry, sizeof(*entry));
347 tcmu_hdr_set_op(&entry->hdr, TCMU_OP_PAD);
348 tcmu_hdr_set_len(&entry->hdr, pad_size);
350 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
352 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
353 WARN_ON(cmd_head != 0);
356 entry = (void *) mb + CMDR_OFF + cmd_head;
357 tcmu_flush_dcache_range(entry, sizeof(*entry));
358 tcmu_hdr_set_op(&entry->hdr, TCMU_OP_CMD);
359 tcmu_hdr_set_len(&entry->hdr, command_size);
360 entry->cmd_id = tcmu_cmd->cmd_id;
363 * Fix up iovecs, and handle if allocation in data ring wrapped.
365 iov = &entry->req.iov[0];
366 for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
367 size_t copy_bytes = min((size_t)sg->length,
368 head_to_end(udev->data_head, udev->data_size));
369 void *from = kmap_atomic(sg_page(sg)) + sg->offset;
370 void *to = (void *) mb + udev->data_off + udev->data_head;
372 if (tcmu_cmd->se_cmd->data_direction == DMA_TO_DEVICE) {
373 memcpy(to, from, copy_bytes);
374 tcmu_flush_dcache_range(to, copy_bytes);
377 /* Even iov_base is relative to mb_addr */
378 iov->iov_len = copy_bytes;
379 iov->iov_base = (void *) udev->data_off + udev->data_head;
383 UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
385 /* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */
386 if (sg->length != copy_bytes) {
388 copy_bytes = sg->length - copy_bytes;
390 iov->iov_len = copy_bytes;
391 iov->iov_base = (void *) udev->data_off + udev->data_head;
393 if (se_cmd->data_direction == DMA_TO_DEVICE) {
394 to = (void *) mb + udev->data_off + udev->data_head;
395 memcpy(to, from, copy_bytes);
396 tcmu_flush_dcache_range(to, copy_bytes);
402 UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
407 entry->req.iov_cnt = iov_cnt;
409 /* All offsets relative to mb_addr, not start of entry! */
410 cdb_off = CMDR_OFF + cmd_head + base_command_size;
411 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
412 entry->req.cdb_off = cdb_off;
413 tcmu_flush_dcache_range(entry, sizeof(*entry));
415 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
416 tcmu_flush_dcache_range(mb, sizeof(*mb));
418 spin_unlock_irq(&udev->cmdr_lock);
420 /* TODO: only if FLUSH and FUA? */
421 uio_event_notify(&udev->uio_info);
423 mod_timer(&udev->timeout,
424 round_jiffies_up(jiffies + msecs_to_jiffies(TCMU_TIME_OUT)));
429 static int tcmu_queue_cmd(struct se_cmd *se_cmd)
431 struct se_device *se_dev = se_cmd->se_dev;
432 struct tcmu_dev *udev = TCMU_DEV(se_dev);
433 struct tcmu_cmd *tcmu_cmd;
436 tcmu_cmd = tcmu_alloc_cmd(se_cmd);
440 ret = tcmu_queue_cmd_ring(tcmu_cmd);
442 pr_err("TCMU: Could not queue command\n");
443 spin_lock_irq(&udev->commands_lock);
444 idr_remove(&udev->commands, tcmu_cmd->cmd_id);
445 spin_unlock_irq(&udev->commands_lock);
447 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
453 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
455 struct se_cmd *se_cmd = cmd->se_cmd;
456 struct tcmu_dev *udev = cmd->tcmu_dev;
458 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
459 /* cmd has been completed already from timeout, just reclaim data
461 UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
465 if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
466 memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer,
467 se_cmd->scsi_sense_length);
469 UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
471 else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
472 struct scatterlist *sg;
475 /* It'd be easier to look at entry's iovec again, but UAM */
476 for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
481 copy_bytes = min((size_t)sg->length,
482 head_to_end(udev->data_tail, udev->data_size));
484 to = kmap_atomic(sg_page(sg)) + sg->offset;
485 WARN_ON(sg->length + sg->offset > PAGE_SIZE);
486 from = (void *) udev->mb_addr + udev->data_off + udev->data_tail;
487 tcmu_flush_dcache_range(from, copy_bytes);
488 memcpy(to, from, copy_bytes);
490 UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
492 /* Uh oh, wrapped the data buffer for this sg's data */
493 if (sg->length != copy_bytes) {
494 from = (void *) udev->mb_addr + udev->data_off + udev->data_tail;
495 WARN_ON(udev->data_tail);
497 copy_bytes = sg->length - copy_bytes;
498 tcmu_flush_dcache_range(from, copy_bytes);
499 memcpy(to, from, copy_bytes);
501 UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
507 } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
508 UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
510 pr_warn("TCMU: data direction was %d!\n", se_cmd->data_direction);
513 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
516 kmem_cache_free(tcmu_cmd_cache, cmd);
519 static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
521 struct tcmu_mailbox *mb;
526 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
527 pr_err("ring broken, not handling completions\n");
531 spin_lock_irqsave(&udev->cmdr_lock, flags);
534 tcmu_flush_dcache_range(mb, sizeof(*mb));
536 while (udev->cmdr_last_cleaned != ACCESS_ONCE(mb->cmd_tail)) {
538 struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
539 struct tcmu_cmd *cmd;
541 tcmu_flush_dcache_range(entry, sizeof(*entry));
543 if (tcmu_hdr_get_op(&entry->hdr) == TCMU_OP_PAD) {
544 UPDATE_HEAD(udev->cmdr_last_cleaned, tcmu_hdr_get_len(&entry->hdr), udev->cmdr_size);
547 WARN_ON(tcmu_hdr_get_op(&entry->hdr) != TCMU_OP_CMD);
549 spin_lock(&udev->commands_lock);
550 cmd = idr_find(&udev->commands, entry->cmd_id);
552 idr_remove(&udev->commands, cmd->cmd_id);
553 spin_unlock(&udev->commands_lock);
556 pr_err("cmd_id not found, ring is broken\n");
557 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
561 tcmu_handle_completion(cmd, entry);
563 UPDATE_HEAD(udev->cmdr_last_cleaned, tcmu_hdr_get_len(&entry->hdr), udev->cmdr_size);
568 if (mb->cmd_tail == mb->cmd_head)
569 del_timer(&udev->timeout); /* no more pending cmds */
571 spin_unlock_irqrestore(&udev->cmdr_lock, flags);
573 wake_up(&udev->wait_cmdr);
578 static int tcmu_check_expired_cmd(int id, void *p, void *data)
580 struct tcmu_cmd *cmd = p;
582 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
585 if (!time_after(cmd->deadline, jiffies))
588 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
589 target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION);
592 kmem_cache_free(tcmu_cmd_cache, cmd);
597 static void tcmu_device_timedout(unsigned long data)
599 struct tcmu_dev *udev = (struct tcmu_dev *)data;
603 handled = tcmu_handle_completions(udev);
605 pr_warn("%d completions handled from timeout\n", handled);
607 spin_lock_irqsave(&udev->commands_lock, flags);
608 idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
609 spin_unlock_irqrestore(&udev->commands_lock, flags);
612 * We don't need to wakeup threads on wait_cmdr since they have their
617 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
619 struct tcmu_hba *tcmu_hba;
621 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
625 tcmu_hba->host_id = host_id;
626 hba->hba_ptr = tcmu_hba;
631 static void tcmu_detach_hba(struct se_hba *hba)
637 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
639 struct tcmu_dev *udev;
641 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
645 udev->name = kstrdup(name, GFP_KERNEL);
653 init_waitqueue_head(&udev->wait_cmdr);
654 spin_lock_init(&udev->cmdr_lock);
656 idr_init(&udev->commands);
657 spin_lock_init(&udev->commands_lock);
659 setup_timer(&udev->timeout, tcmu_device_timedout,
660 (unsigned long)udev);
662 udev->pass_level = TCMU_PASS_ALL;
664 return &udev->se_dev;
667 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
669 struct tcmu_dev *tcmu_dev = container_of(info, struct tcmu_dev, uio_info);
671 tcmu_handle_completions(tcmu_dev);
677 * mmap code from uio.c. Copied here because we want to hook mmap()
678 * and this stuff must come along.
680 static int tcmu_find_mem_index(struct vm_area_struct *vma)
682 struct tcmu_dev *udev = vma->vm_private_data;
683 struct uio_info *info = &udev->uio_info;
685 if (vma->vm_pgoff < MAX_UIO_MAPS) {
686 if (info->mem[vma->vm_pgoff].size == 0)
688 return (int)vma->vm_pgoff;
693 static int tcmu_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
695 struct tcmu_dev *udev = vma->vm_private_data;
696 struct uio_info *info = &udev->uio_info;
698 unsigned long offset;
701 int mi = tcmu_find_mem_index(vma);
703 return VM_FAULT_SIGBUS;
706 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
709 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
711 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
712 if (info->mem[mi].memtype == UIO_MEM_LOGICAL)
713 page = virt_to_page(addr);
715 page = vmalloc_to_page(addr);
721 static const struct vm_operations_struct tcmu_vm_ops = {
722 .fault = tcmu_vma_fault,
725 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
727 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
729 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
730 vma->vm_ops = &tcmu_vm_ops;
732 vma->vm_private_data = udev;
734 /* Ensure the mmap is exactly the right size */
735 if (vma_pages(vma) != (TCMU_RING_SIZE >> PAGE_SHIFT))
741 static int tcmu_open(struct uio_info *info, struct inode *inode)
743 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
745 /* O_EXCL not supported for char devs, so fake it? */
746 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
754 static int tcmu_release(struct uio_info *info, struct inode *inode)
756 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
758 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
765 static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int minor)
771 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
775 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
779 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, name);
783 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, minor);
787 ret = genlmsg_end(skb, msg_header);
791 ret = genlmsg_multicast(&tcmu_genl_family, skb, 0,
792 TCMU_MCGRP_CONFIG, GFP_KERNEL);
794 /* We don't care if no one is listening */
804 static int tcmu_configure_device(struct se_device *dev)
806 struct tcmu_dev *udev = TCMU_DEV(dev);
807 struct tcmu_hba *hba = udev->hba->hba_ptr;
808 struct uio_info *info;
809 struct tcmu_mailbox *mb;
815 info = &udev->uio_info;
817 size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
819 size += 1; /* for \0 */
820 str = kmalloc(size, GFP_KERNEL);
824 used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
826 if (udev->dev_config[0])
827 snprintf(str + used, size - used, "/%s", udev->dev_config);
831 udev->mb_addr = vzalloc(TCMU_RING_SIZE);
832 if (!udev->mb_addr) {
837 /* mailbox fits in first part of CMDR space */
838 udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
839 udev->data_off = CMDR_SIZE;
840 udev->data_size = TCMU_RING_SIZE - CMDR_SIZE;
844 mb->cmdr_off = CMDR_OFF;
845 mb->cmdr_size = udev->cmdr_size;
847 WARN_ON(!PAGE_ALIGNED(udev->data_off));
848 WARN_ON(udev->data_size % PAGE_SIZE);
852 info->mem[0].name = "tcm-user command & data buffer";
853 info->mem[0].addr = (phys_addr_t) udev->mb_addr;
854 info->mem[0].size = TCMU_RING_SIZE;
855 info->mem[0].memtype = UIO_MEM_VIRTUAL;
857 info->irqcontrol = tcmu_irqcontrol;
858 info->irq = UIO_IRQ_CUSTOM;
860 info->mmap = tcmu_mmap;
861 info->open = tcmu_open;
862 info->release = tcmu_release;
864 ret = uio_register_device(tcmu_root_device, info);
868 /* Other attributes can be configured in userspace */
869 dev->dev_attrib.hw_block_size = 512;
870 dev->dev_attrib.hw_max_sectors = 128;
871 dev->dev_attrib.hw_queue_depth = 128;
873 ret = tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE, udev->uio_info.name,
874 udev->uio_info.uio_dev->minor);
881 uio_unregister_device(&udev->uio_info);
883 vfree(udev->mb_addr);
890 static int tcmu_check_pending_cmd(int id, void *p, void *data)
892 struct tcmu_cmd *cmd = p;
894 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
899 static void tcmu_free_device(struct se_device *dev)
901 struct tcmu_dev *udev = TCMU_DEV(dev);
904 del_timer_sync(&udev->timeout);
906 vfree(udev->mb_addr);
908 /* Upper layer should drain all requests before calling this */
909 spin_lock_irq(&udev->commands_lock);
910 i = idr_for_each(&udev->commands, tcmu_check_pending_cmd, NULL);
911 idr_destroy(&udev->commands);
912 spin_unlock_irq(&udev->commands_lock);
915 /* Device was configured */
916 if (udev->uio_info.uio_dev) {
917 tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name,
918 udev->uio_info.uio_dev->minor);
920 uio_unregister_device(&udev->uio_info);
921 kfree(udev->uio_info.name);
929 Opt_dev_config, Opt_dev_size, Opt_err, Opt_pass_level,
932 static match_table_t tokens = {
933 {Opt_dev_config, "dev_config=%s"},
934 {Opt_dev_size, "dev_size=%u"},
935 {Opt_pass_level, "pass_level=%u"},
939 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
940 const char *page, ssize_t count)
942 struct tcmu_dev *udev = TCMU_DEV(dev);
943 char *orig, *ptr, *opts, *arg_p;
944 substring_t args[MAX_OPT_ARGS];
948 opts = kstrdup(page, GFP_KERNEL);
954 while ((ptr = strsep(&opts, ",\n")) != NULL) {
958 token = match_token(ptr, tokens, args);
961 if (match_strlcpy(udev->dev_config, &args[0],
962 TCMU_CONFIG_LEN) == 0) {
966 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
969 arg_p = match_strdup(&args[0]);
974 ret = kstrtoul(arg_p, 0, (unsigned long *) &udev->dev_size);
977 pr_err("kstrtoul() failed for dev_size=\n");
980 match_int(args, &arg);
981 if (arg >= TCMU_PASS_INVALID) {
982 pr_warn("TCMU: Invalid pass_level: %d\n", arg);
986 pr_debug("TCMU: Setting pass_level to %d\n", arg);
987 udev->pass_level = arg;
995 return (!ret) ? count : ret;
998 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
1000 struct tcmu_dev *udev = TCMU_DEV(dev);
1003 bl = sprintf(b + bl, "Config: %s ",
1004 udev->dev_config[0] ? udev->dev_config : "NULL");
1005 bl += sprintf(b + bl, "Size: %zu PassLevel: %u\n",
1006 udev->dev_size, udev->pass_level);
1011 static sector_t tcmu_get_blocks(struct se_device *dev)
1013 struct tcmu_dev *udev = TCMU_DEV(dev);
1015 return div_u64(udev->dev_size - dev->dev_attrib.block_size,
1016 dev->dev_attrib.block_size);
1019 static sense_reason_t
1020 tcmu_execute_rw(struct se_cmd *se_cmd, struct scatterlist *sgl, u32 sgl_nents,
1021 enum dma_data_direction data_direction)
1025 ret = tcmu_queue_cmd(se_cmd);
1028 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1030 return TCM_NO_SENSE;
1033 static sense_reason_t
1034 tcmu_pass_op(struct se_cmd *se_cmd)
1036 int ret = tcmu_queue_cmd(se_cmd);
1039 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1041 return TCM_NO_SENSE;
1044 static struct sbc_ops tcmu_sbc_ops = {
1045 .execute_rw = tcmu_execute_rw,
1046 .execute_sync_cache = tcmu_pass_op,
1047 .execute_write_same = tcmu_pass_op,
1048 .execute_write_same_unmap = tcmu_pass_op,
1049 .execute_unmap = tcmu_pass_op,
1052 static sense_reason_t
1053 tcmu_parse_cdb(struct se_cmd *cmd)
1055 unsigned char *cdb = cmd->t_task_cdb;
1056 struct tcmu_dev *udev = TCMU_DEV(cmd->se_dev);
1059 switch (udev->pass_level) {
1061 /* We're just like pscsi, then */
1063 * For REPORT LUNS we always need to emulate the response, for everything
1068 cmd->execute_cmd = spc_emulate_report_luns;
1079 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
1082 cmd->execute_cmd = tcmu_pass_op;
1087 ret = sbc_parse_cdb(cmd, &tcmu_sbc_ops);
1090 pr_err("Unknown tcm-user pass level %d\n", udev->pass_level);
1091 ret = TCM_CHECK_CONDITION_ABORT_CMD;
1097 DEF_TB_DEFAULT_ATTRIBS(tcmu);
1099 static struct configfs_attribute *tcmu_backend_dev_attrs[] = {
1100 &tcmu_dev_attrib_emulate_model_alias.attr,
1101 &tcmu_dev_attrib_emulate_dpo.attr,
1102 &tcmu_dev_attrib_emulate_fua_write.attr,
1103 &tcmu_dev_attrib_emulate_fua_read.attr,
1104 &tcmu_dev_attrib_emulate_write_cache.attr,
1105 &tcmu_dev_attrib_emulate_ua_intlck_ctrl.attr,
1106 &tcmu_dev_attrib_emulate_tas.attr,
1107 &tcmu_dev_attrib_emulate_tpu.attr,
1108 &tcmu_dev_attrib_emulate_tpws.attr,
1109 &tcmu_dev_attrib_emulate_caw.attr,
1110 &tcmu_dev_attrib_emulate_3pc.attr,
1111 &tcmu_dev_attrib_pi_prot_type.attr,
1112 &tcmu_dev_attrib_hw_pi_prot_type.attr,
1113 &tcmu_dev_attrib_pi_prot_format.attr,
1114 &tcmu_dev_attrib_enforce_pr_isids.attr,
1115 &tcmu_dev_attrib_is_nonrot.attr,
1116 &tcmu_dev_attrib_emulate_rest_reord.attr,
1117 &tcmu_dev_attrib_force_pr_aptpl.attr,
1118 &tcmu_dev_attrib_hw_block_size.attr,
1119 &tcmu_dev_attrib_block_size.attr,
1120 &tcmu_dev_attrib_hw_max_sectors.attr,
1121 &tcmu_dev_attrib_fabric_max_sectors.attr,
1122 &tcmu_dev_attrib_optimal_sectors.attr,
1123 &tcmu_dev_attrib_hw_queue_depth.attr,
1124 &tcmu_dev_attrib_queue_depth.attr,
1125 &tcmu_dev_attrib_max_unmap_lba_count.attr,
1126 &tcmu_dev_attrib_max_unmap_block_desc_count.attr,
1127 &tcmu_dev_attrib_unmap_granularity.attr,
1128 &tcmu_dev_attrib_unmap_granularity_alignment.attr,
1129 &tcmu_dev_attrib_max_write_same_len.attr,
1133 static struct se_subsystem_api tcmu_template = {
1135 .inquiry_prod = "USER",
1136 .inquiry_rev = TCMU_VERSION,
1137 .owner = THIS_MODULE,
1138 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
1139 .attach_hba = tcmu_attach_hba,
1140 .detach_hba = tcmu_detach_hba,
1141 .alloc_device = tcmu_alloc_device,
1142 .configure_device = tcmu_configure_device,
1143 .free_device = tcmu_free_device,
1144 .parse_cdb = tcmu_parse_cdb,
1145 .set_configfs_dev_params = tcmu_set_configfs_dev_params,
1146 .show_configfs_dev_params = tcmu_show_configfs_dev_params,
1147 .get_device_type = sbc_get_device_type,
1148 .get_blocks = tcmu_get_blocks,
1151 static int __init tcmu_module_init(void)
1153 struct target_backend_cits *tbc = &tcmu_template.tb_cits;
1156 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
1158 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
1159 sizeof(struct tcmu_cmd),
1160 __alignof__(struct tcmu_cmd),
1162 if (!tcmu_cmd_cache)
1165 tcmu_root_device = root_device_register("tcm_user");
1166 if (IS_ERR(tcmu_root_device)) {
1167 ret = PTR_ERR(tcmu_root_device);
1168 goto out_free_cache;
1171 ret = genl_register_family(&tcmu_genl_family);
1173 goto out_unreg_device;
1176 target_core_setup_sub_cits(&tcmu_template);
1177 tbc->tb_dev_attrib_cit.ct_attrs = tcmu_backend_dev_attrs;
1179 ret = transport_subsystem_register(&tcmu_template);
1181 goto out_unreg_genl;
1186 genl_unregister_family(&tcmu_genl_family);
1188 root_device_unregister(tcmu_root_device);
1190 kmem_cache_destroy(tcmu_cmd_cache);
1195 static void __exit tcmu_module_exit(void)
1197 transport_subsystem_release(&tcmu_template);
1198 genl_unregister_family(&tcmu_genl_family);
1199 root_device_unregister(tcmu_root_device);
1200 kmem_cache_destroy(tcmu_cmd_cache);
1203 MODULE_DESCRIPTION("TCM USER subsystem plugin");
1204 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
1205 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
1206 MODULE_LICENSE("GPL");
1208 module_init(tcmu_module_init);
1209 module_exit(tcmu_module_exit);