1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2013 Shaohua Li <shli@kernel.org>
4 * Copyright (C) 2014 Red Hat, Inc.
5 * Copyright (C) 2015 Arrikto, Inc.
6 * Copyright (C) 2017 Chinamobile, Inc.
7 */
8
9 #include <linux/spinlock.h>
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/timer.h>
13 #include <linux/parser.h>
14 #include <linux/vmalloc.h>
15 #include <linux/uio_driver.h>
16 #include <linux/xarray.h>
17 #include <linux/stringify.h>
18 #include <linux/bitops.h>
19 #include <linux/highmem.h>
20 #include <linux/configfs.h>
21 #include <linux/mutex.h>
22 #include <linux/workqueue.h>
23 #include <net/genetlink.h>
24 #include <scsi/scsi_common.h>
25 #include <scsi/scsi_proto.h>
26 #include <target/target_core_base.h>
27 #include <target/target_core_fabric.h>
28 #include <target/target_core_backend.h>
29
30 #include <linux/target_core_user.h>
31
32 /**
33 * DOC: Userspace I/O
34 * Userspace I/O
35 * -------------
36 *
37 * Define a shared-memory interface for LIO to pass SCSI commands and
38 * data to userspace for processing. This is to allow backends that
39 * are too complex for in-kernel support to be possible.
40 *
41 * It uses the UIO framework to do a lot of the device-creation and
42 * introspection work for us.
43 *
44 * See the .h file for how the ring is laid out. Note that while the
45 * command ring is defined, the particulars of the data area are
46 * not. Offset values in the command entry point to other locations
47 * internal to the mmap-ed area. There is separate space outside the
48 * command ring for data buffers. This leaves maximum flexibility for
49 * moving buffer allocations, or even page flipping or other
50 * allocation techniques, without altering the command ring layout.
51 *
52 * SECURITY:
53 * The user process must be assumed to be malicious. There's no way to
54 * prevent it breaking the command ring protocol if it wants, but in
55 * order to prevent other issues we must only ever read *data* from
56 * the shared memory area, not offsets or sizes. This applies to
57 * command ring entries as well as the mailbox. Extra code needed for
58 * this may have a 'UAM' comment.
59 */
60
61 #define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
62
63 /* For mailbox plus cmd ring, the size is fixed 8MB */
64 #define MB_CMDR_SIZE (8 * 1024 * 1024)
65 /* Offset of cmd ring is size of mailbox */
66 #define CMDR_OFF sizeof(struct tcmu_mailbox)
67 #define CMDR_SIZE (MB_CMDR_SIZE - CMDR_OFF)
68
69 /*
70 * For data area, the default block size is PAGE_SIZE and
71 * the default total size is 256K * PAGE_SIZE.
72 */
73 #define DATA_PAGES_PER_BLK_DEF 1
74 #define DATA_AREA_PAGES_DEF (256 * 1024)
75
76 #define TCMU_MBS_TO_PAGES(_mbs) ((size_t)_mbs << (20 - PAGE_SHIFT))
77 #define TCMU_PAGES_TO_MBS(_pages) (_pages >> (20 - PAGE_SHIFT))
78
79 /*
80 * Default number of global data blocks(512K * PAGE_SIZE)
81 * when the unmap thread will be started.
82 */
83 #define TCMU_GLOBAL_MAX_PAGES_DEF (512 * 1024)
84
85 static u8 tcmu_kern_cmd_reply_supported;
86 static u8 tcmu_netlink_blocked;
87
88 static struct device *tcmu_root_device;
89
90 struct tcmu_hba {
91 u32 host_id;
92 };
93
94 #define TCMU_CONFIG_LEN 256
95
96 static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
97 static LIST_HEAD(tcmu_nl_cmd_list);
98
99 struct tcmu_dev;
100
101 struct tcmu_nl_cmd {
102 /* wake up thread waiting for reply */
103 struct completion complete;
104 struct list_head nl_list;
105 struct tcmu_dev *udev;
106 int cmd;
107 int status;
108 };
109
110 struct tcmu_dev {
111 struct list_head node;
112 struct kref kref;
113
114 struct se_device se_dev;
115 struct se_dev_plug se_plug;
116
117 char *name;
118 struct se_hba *hba;
119
120 #define TCMU_DEV_BIT_OPEN 0
121 #define TCMU_DEV_BIT_BROKEN 1
122 #define TCMU_DEV_BIT_BLOCKED 2
123 #define TCMU_DEV_BIT_TMR_NOTIFY 3
124 #define TCM_DEV_BIT_PLUGGED 4
125 unsigned long flags;
126
127 struct uio_info uio_info;
128
129 struct inode *inode;
130
131 uint64_t dev_size;
132
133 struct tcmu_mailbox *mb_addr;
134 void *cmdr;
135 u32 cmdr_size;
136 u32 cmdr_last_cleaned;
137 /* Offset of data area from start of mb */
138 /* Must add data_off and mb_addr to get the address */
139 size_t data_off;
140 int data_area_mb;
141 uint32_t max_blocks;
142 size_t mmap_pages;
143
144 struct mutex cmdr_lock;
145 struct list_head qfull_queue;
146 struct list_head tmr_queue;
147
148 uint32_t dbi_max;
149 uint32_t dbi_thresh;
150 unsigned long *data_bitmap;
151 struct xarray data_pages;
152 uint32_t data_pages_per_blk;
153 uint32_t data_blk_size;
154
155 struct xarray commands;
156
157 struct timer_list cmd_timer;
158 unsigned int cmd_time_out;
159 struct list_head inflight_queue;
160
161 struct timer_list qfull_timer;
162 int qfull_time_out;
163
164 struct list_head timedout_entry;
165
166 struct tcmu_nl_cmd curr_nl_cmd;
167
168 char dev_config[TCMU_CONFIG_LEN];
169
170 int nl_reply_supported;
171 };
172
173 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
174
175 struct tcmu_cmd {
176 struct se_cmd *se_cmd;
177 struct tcmu_dev *tcmu_dev;
178 struct list_head queue_entry;
179
180 uint16_t cmd_id;
181
182 /* Can't use se_cmd when cleaning up expired cmds, because if
183 cmd has been completed then accessing se_cmd is off limits */
184 uint32_t dbi_cnt;
185 uint32_t dbi_bidi_cnt;
186 uint32_t dbi_cur;
187 uint32_t *dbi;
188
189 uint32_t data_len_bidi;
190
191 unsigned long deadline;
192
193 #define TCMU_CMD_BIT_EXPIRED 0
194 unsigned long flags;
195 };
196
197 struct tcmu_tmr {
198 struct list_head queue_entry;
199
200 uint8_t tmr_type;
201 uint32_t tmr_cmd_cnt;
202 int16_t tmr_cmd_ids[];
203 };
204
205 /*
206 * To avoid dead lock the mutex lock order should always be:
207 *
208 * mutex_lock(&root_udev_mutex);
209 * ...
210 * mutex_lock(&tcmu_dev->cmdr_lock);
211 * mutex_unlock(&tcmu_dev->cmdr_lock);
212 * ...
213 * mutex_unlock(&root_udev_mutex);
214 */
215 static DEFINE_MUTEX(root_udev_mutex);
216 static LIST_HEAD(root_udev);
217
218 static DEFINE_SPINLOCK(timed_out_udevs_lock);
219 static LIST_HEAD(timed_out_udevs);
220
221 static struct kmem_cache *tcmu_cmd_cache;
222
223 static atomic_t global_page_count = ATOMIC_INIT(0);
224 static struct delayed_work tcmu_unmap_work;
225 static int tcmu_global_max_pages = TCMU_GLOBAL_MAX_PAGES_DEF;
226
tcmu_set_global_max_data_area(const char * str,const struct kernel_param * kp)227 static int tcmu_set_global_max_data_area(const char *str,
228 const struct kernel_param *kp)
229 {
230 int ret, max_area_mb;
231
232 ret = kstrtoint(str, 10, &max_area_mb);
233 if (ret)
234 return -EINVAL;
235
236 if (max_area_mb <= 0) {
237 pr_err("global_max_data_area must be larger than 0.\n");
238 return -EINVAL;
239 }
240
241 tcmu_global_max_pages = TCMU_MBS_TO_PAGES(max_area_mb);
242 if (atomic_read(&global_page_count) > tcmu_global_max_pages)
243 schedule_delayed_work(&tcmu_unmap_work, 0);
244 else
245 cancel_delayed_work_sync(&tcmu_unmap_work);
246
247 return 0;
248 }
249
tcmu_get_global_max_data_area(char * buffer,const struct kernel_param * kp)250 static int tcmu_get_global_max_data_area(char *buffer,
251 const struct kernel_param *kp)
252 {
253 return sprintf(buffer, "%d\n", TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
254 }
255
256 static const struct kernel_param_ops tcmu_global_max_data_area_op = {
257 .set = tcmu_set_global_max_data_area,
258 .get = tcmu_get_global_max_data_area,
259 };
260
261 module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
262 S_IWUSR | S_IRUGO);
263 MODULE_PARM_DESC(global_max_data_area_mb,
264 "Max MBs allowed to be allocated to all the tcmu device's "
265 "data areas.");
266
tcmu_get_block_netlink(char * buffer,const struct kernel_param * kp)267 static int tcmu_get_block_netlink(char *buffer,
268 const struct kernel_param *kp)
269 {
270 return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
271 "blocked" : "unblocked");
272 }
273
tcmu_set_block_netlink(const char * str,const struct kernel_param * kp)274 static int tcmu_set_block_netlink(const char *str,
275 const struct kernel_param *kp)
276 {
277 int ret;
278 u8 val;
279
280 ret = kstrtou8(str, 0, &val);
281 if (ret < 0)
282 return ret;
283
284 if (val > 1) {
285 pr_err("Invalid block netlink value %u\n", val);
286 return -EINVAL;
287 }
288
289 tcmu_netlink_blocked = val;
290 return 0;
291 }
292
293 static const struct kernel_param_ops tcmu_block_netlink_op = {
294 .set = tcmu_set_block_netlink,
295 .get = tcmu_get_block_netlink,
296 };
297
298 module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
299 MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
300
tcmu_fail_netlink_cmd(struct tcmu_nl_cmd * nl_cmd)301 static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
302 {
303 struct tcmu_dev *udev = nl_cmd->udev;
304
305 if (!tcmu_netlink_blocked) {
306 pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
307 return -EBUSY;
308 }
309
310 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
311 pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
312 nl_cmd->status = -EINTR;
313 list_del(&nl_cmd->nl_list);
314 complete(&nl_cmd->complete);
315 }
316 return 0;
317 }
318
tcmu_set_reset_netlink(const char * str,const struct kernel_param * kp)319 static int tcmu_set_reset_netlink(const char *str,
320 const struct kernel_param *kp)
321 {
322 struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
323 int ret;
324 u8 val;
325
326 ret = kstrtou8(str, 0, &val);
327 if (ret < 0)
328 return ret;
329
330 if (val != 1) {
331 pr_err("Invalid reset netlink value %u\n", val);
332 return -EINVAL;
333 }
334
335 mutex_lock(&tcmu_nl_cmd_mutex);
336 list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
337 ret = tcmu_fail_netlink_cmd(nl_cmd);
338 if (ret)
339 break;
340 }
341 mutex_unlock(&tcmu_nl_cmd_mutex);
342
343 return ret;
344 }
345
346 static const struct kernel_param_ops tcmu_reset_netlink_op = {
347 .set = tcmu_set_reset_netlink,
348 };
349
350 module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
351 MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
352
353 /* multicast group */
354 enum tcmu_multicast_groups {
355 TCMU_MCGRP_CONFIG,
356 };
357
358 static const struct genl_multicast_group tcmu_mcgrps[] = {
359 [TCMU_MCGRP_CONFIG] = { .name = "config", },
360 };
361
362 static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
363 [TCMU_ATTR_DEVICE] = { .type = NLA_STRING },
364 [TCMU_ATTR_MINOR] = { .type = NLA_U32 },
365 [TCMU_ATTR_CMD_STATUS] = { .type = NLA_S32 },
366 [TCMU_ATTR_DEVICE_ID] = { .type = NLA_U32 },
367 [TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
368 };
369
tcmu_genl_cmd_done(struct genl_info * info,int completed_cmd)370 static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
371 {
372 struct tcmu_dev *udev = NULL;
373 struct tcmu_nl_cmd *nl_cmd;
374 int dev_id, rc, ret = 0;
375
376 if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
377 !info->attrs[TCMU_ATTR_DEVICE_ID]) {
378 printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
379 return -EINVAL;
380 }
381
382 dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
383 rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
384
385 mutex_lock(&tcmu_nl_cmd_mutex);
386 list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
387 if (nl_cmd->udev->se_dev.dev_index == dev_id) {
388 udev = nl_cmd->udev;
389 break;
390 }
391 }
392
393 if (!udev) {
394 pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
395 completed_cmd, rc, dev_id);
396 ret = -ENODEV;
397 goto unlock;
398 }
399 list_del(&nl_cmd->nl_list);
400
401 pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
402 udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
403 nl_cmd->status);
404
405 if (nl_cmd->cmd != completed_cmd) {
406 pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
407 udev->name, completed_cmd, nl_cmd->cmd);
408 ret = -EINVAL;
409 goto unlock;
410 }
411
412 nl_cmd->status = rc;
413 complete(&nl_cmd->complete);
414 unlock:
415 mutex_unlock(&tcmu_nl_cmd_mutex);
416 return ret;
417 }
418
tcmu_genl_rm_dev_done(struct sk_buff * skb,struct genl_info * info)419 static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
420 {
421 return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
422 }
423
tcmu_genl_add_dev_done(struct sk_buff * skb,struct genl_info * info)424 static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
425 {
426 return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
427 }
428
tcmu_genl_reconfig_dev_done(struct sk_buff * skb,struct genl_info * info)429 static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
430 struct genl_info *info)
431 {
432 return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
433 }
434
tcmu_genl_set_features(struct sk_buff * skb,struct genl_info * info)435 static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
436 {
437 if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
438 tcmu_kern_cmd_reply_supported =
439 nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
440 printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
441 tcmu_kern_cmd_reply_supported);
442 }
443
444 return 0;
445 }
446
447 static const struct genl_small_ops tcmu_genl_ops[] = {
448 {
449 .cmd = TCMU_CMD_SET_FEATURES,
450 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
451 .flags = GENL_ADMIN_PERM,
452 .doit = tcmu_genl_set_features,
453 },
454 {
455 .cmd = TCMU_CMD_ADDED_DEVICE_DONE,
456 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
457 .flags = GENL_ADMIN_PERM,
458 .doit = tcmu_genl_add_dev_done,
459 },
460 {
461 .cmd = TCMU_CMD_REMOVED_DEVICE_DONE,
462 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
463 .flags = GENL_ADMIN_PERM,
464 .doit = tcmu_genl_rm_dev_done,
465 },
466 {
467 .cmd = TCMU_CMD_RECONFIG_DEVICE_DONE,
468 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
469 .flags = GENL_ADMIN_PERM,
470 .doit = tcmu_genl_reconfig_dev_done,
471 },
472 };
473
474 /* Our generic netlink family */
475 static struct genl_family tcmu_genl_family __ro_after_init = {
476 .module = THIS_MODULE,
477 .hdrsize = 0,
478 .name = "TCM-USER",
479 .version = 2,
480 .maxattr = TCMU_ATTR_MAX,
481 .policy = tcmu_attr_policy,
482 .mcgrps = tcmu_mcgrps,
483 .n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
484 .netnsok = true,
485 .small_ops = tcmu_genl_ops,
486 .n_small_ops = ARRAY_SIZE(tcmu_genl_ops),
487 };
488
489 #define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
490 #define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
491 #define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
492 #define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
493
tcmu_cmd_free_data(struct tcmu_cmd * tcmu_cmd,uint32_t len)494 static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
495 {
496 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
497 uint32_t i;
498
499 for (i = 0; i < len; i++)
500 clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
501 }
502
tcmu_get_empty_block(struct tcmu_dev * udev,struct tcmu_cmd * tcmu_cmd,int prev_dbi,int length,int * iov_cnt)503 static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
504 struct tcmu_cmd *tcmu_cmd,
505 int prev_dbi, int length, int *iov_cnt)
506 {
507 XA_STATE(xas, &udev->data_pages, 0);
508 struct page *page;
509 int i, cnt, dbi, dpi;
510 int page_cnt = DIV_ROUND_UP(length, PAGE_SIZE);
511
512 dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
513 if (dbi == udev->dbi_thresh)
514 return -1;
515
516 dpi = dbi * udev->data_pages_per_blk;
517 /* Count the number of already allocated pages */
518 xas_set(&xas, dpi);
519 for (cnt = 0; xas_next(&xas) && cnt < page_cnt;)
520 cnt++;
521
522 for (i = cnt; i < page_cnt; i++) {
523 /* try to get new page from the mm */
524 page = alloc_page(GFP_NOIO);
525 if (!page)
526 break;
527
528 if (xa_store(&udev->data_pages, dpi + i, page, GFP_NOIO)) {
529 __free_page(page);
530 break;
531 }
532 }
533 if (atomic_add_return(i - cnt, &global_page_count) >
534 tcmu_global_max_pages)
535 schedule_delayed_work(&tcmu_unmap_work, 0);
536
537 if (i && dbi > udev->dbi_max)
538 udev->dbi_max = dbi;
539
540 set_bit(dbi, udev->data_bitmap);
541 tcmu_cmd_set_dbi(tcmu_cmd, dbi);
542
543 if (dbi != prev_dbi + 1)
544 *iov_cnt += 1;
545
546 return i == page_cnt ? dbi : -1;
547 }
548
tcmu_get_empty_blocks(struct tcmu_dev * udev,struct tcmu_cmd * tcmu_cmd,int length)549 static int tcmu_get_empty_blocks(struct tcmu_dev *udev,
550 struct tcmu_cmd *tcmu_cmd, int length)
551 {
552 /* start value of dbi + 1 must not be a valid dbi */
553 int dbi = -2;
554 int blk_data_len, iov_cnt = 0;
555 uint32_t blk_size = udev->data_blk_size;
556
557 for (; length > 0; length -= blk_size) {
558 blk_data_len = min_t(uint32_t, length, blk_size);
559 dbi = tcmu_get_empty_block(udev, tcmu_cmd, dbi, blk_data_len,
560 &iov_cnt);
561 if (dbi < 0)
562 return -1;
563 }
564 return iov_cnt;
565 }
566
tcmu_free_cmd(struct tcmu_cmd * tcmu_cmd)567 static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
568 {
569 kfree(tcmu_cmd->dbi);
570 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
571 }
572
tcmu_cmd_set_block_cnts(struct tcmu_cmd * cmd)573 static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd)
574 {
575 int i, len;
576 struct se_cmd *se_cmd = cmd->se_cmd;
577 uint32_t blk_size = cmd->tcmu_dev->data_blk_size;
578
579 cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, blk_size);
580
581 if (se_cmd->se_cmd_flags & SCF_BIDI) {
582 BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
583 for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++)
584 len += se_cmd->t_bidi_data_sg[i].length;
585 cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, blk_size);
586 cmd->dbi_cnt += cmd->dbi_bidi_cnt;
587 cmd->data_len_bidi = len;
588 }
589 }
590
new_block_to_iov(struct tcmu_dev * udev,struct tcmu_cmd * cmd,struct iovec ** iov,int prev_dbi,int len)591 static int new_block_to_iov(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
592 struct iovec **iov, int prev_dbi, int len)
593 {
594 /* Get the next dbi */
595 int dbi = tcmu_cmd_get_dbi(cmd);
596
597 /* Do not add more than udev->data_blk_size to iov */
598 len = min_t(int, len, udev->data_blk_size);
599
600 /*
601 * The following code will gather and map the blocks to the same iovec
602 * when the blocks are all next to each other.
603 */
604 if (dbi != prev_dbi + 1) {
605 /* dbi is not next to previous dbi, so start new iov */
606 if (prev_dbi >= 0)
607 (*iov)++;
608 /* write offset relative to mb_addr */
609 (*iov)->iov_base = (void __user *)
610 (udev->data_off + dbi * udev->data_blk_size);
611 }
612 (*iov)->iov_len += len;
613
614 return dbi;
615 }
616
tcmu_setup_iovs(struct tcmu_dev * udev,struct tcmu_cmd * cmd,struct iovec ** iov,int data_length)617 static void tcmu_setup_iovs(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
618 struct iovec **iov, int data_length)
619 {
620 /* start value of dbi + 1 must not be a valid dbi */
621 int dbi = -2;
622
623 /* We prepare the IOVs for DMA_FROM_DEVICE transfer direction */
624 for (; data_length > 0; data_length -= udev->data_blk_size)
625 dbi = new_block_to_iov(udev, cmd, iov, dbi, data_length);
626 }
627
tcmu_alloc_cmd(struct se_cmd * se_cmd)628 static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
629 {
630 struct se_device *se_dev = se_cmd->se_dev;
631 struct tcmu_dev *udev = TCMU_DEV(se_dev);
632 struct tcmu_cmd *tcmu_cmd;
633
634 tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_NOIO);
635 if (!tcmu_cmd)
636 return NULL;
637
638 INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
639 tcmu_cmd->se_cmd = se_cmd;
640 tcmu_cmd->tcmu_dev = udev;
641
642 tcmu_cmd_set_block_cnts(tcmu_cmd);
643 tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
644 GFP_NOIO);
645 if (!tcmu_cmd->dbi) {
646 kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
647 return NULL;
648 }
649
650 return tcmu_cmd;
651 }
652
tcmu_flush_dcache_range(void * vaddr,size_t size)653 static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
654 {
655 unsigned long offset = offset_in_page(vaddr);
656 void *start = vaddr - offset;
657
658 size = round_up(size+offset, PAGE_SIZE);
659
660 while (size) {
661 flush_dcache_page(vmalloc_to_page(start));
662 start += PAGE_SIZE;
663 size -= PAGE_SIZE;
664 }
665 }
666
667 /*
668 * Some ring helper functions. We don't assume size is a power of 2 so
669 * we can't use circ_buf.h.
670 */
spc_used(size_t head,size_t tail,size_t size)671 static inline size_t spc_used(size_t head, size_t tail, size_t size)
672 {
673 int diff = head - tail;
674
675 if (diff >= 0)
676 return diff;
677 else
678 return size + diff;
679 }
680
spc_free(size_t head,size_t tail,size_t size)681 static inline size_t spc_free(size_t head, size_t tail, size_t size)
682 {
683 /* Keep 1 byte unused or we can't tell full from empty */
684 return (size - spc_used(head, tail, size) - 1);
685 }
686
head_to_end(size_t head,size_t size)687 static inline size_t head_to_end(size_t head, size_t size)
688 {
689 return size - head;
690 }
691
692 #define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
693
694 #define TCMU_SG_TO_DATA_AREA 1
695 #define TCMU_DATA_AREA_TO_SG 2
696
tcmu_copy_data(struct tcmu_dev * udev,struct tcmu_cmd * tcmu_cmd,uint32_t direction,struct scatterlist * sg,unsigned int sg_nents,struct iovec ** iov,size_t data_len)697 static inline void tcmu_copy_data(struct tcmu_dev *udev,
698 struct tcmu_cmd *tcmu_cmd, uint32_t direction,
699 struct scatterlist *sg, unsigned int sg_nents,
700 struct iovec **iov, size_t data_len)
701 {
702 XA_STATE(xas, &udev->data_pages, 0);
703 /* start value of dbi + 1 must not be a valid dbi */
704 int dbi = -2;
705 size_t page_remaining, cp_len;
706 int page_cnt, page_inx;
707 struct sg_mapping_iter sg_iter;
708 unsigned int sg_flags;
709 struct page *page;
710 void *data_page_start, *data_addr;
711
712 if (direction == TCMU_SG_TO_DATA_AREA)
713 sg_flags = SG_MITER_ATOMIC | SG_MITER_FROM_SG;
714 else
715 sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
716 sg_miter_start(&sg_iter, sg, sg_nents, sg_flags);
717
718 while (data_len) {
719 if (direction == TCMU_SG_TO_DATA_AREA)
720 dbi = new_block_to_iov(udev, tcmu_cmd, iov, dbi,
721 data_len);
722 else
723 dbi = tcmu_cmd_get_dbi(tcmu_cmd);
724
725 page_cnt = DIV_ROUND_UP(data_len, PAGE_SIZE);
726 if (page_cnt > udev->data_pages_per_blk)
727 page_cnt = udev->data_pages_per_blk;
728
729 xas_set(&xas, dbi * udev->data_pages_per_blk);
730 for (page_inx = 0; page_inx < page_cnt && data_len; page_inx++) {
731 page = xas_next(&xas);
732
733 if (direction == TCMU_DATA_AREA_TO_SG)
734 flush_dcache_page(page);
735 data_page_start = kmap_atomic(page);
736 page_remaining = PAGE_SIZE;
737
738 while (page_remaining && data_len) {
739 if (!sg_miter_next(&sg_iter)) {
740 /* set length to 0 to abort outer loop */
741 data_len = 0;
742 pr_debug("%s: aborting data copy due to exhausted sg_list\n",
743 __func__);
744 break;
745 }
746 cp_len = min3(sg_iter.length, page_remaining,
747 data_len);
748
749 data_addr = data_page_start +
750 PAGE_SIZE - page_remaining;
751 if (direction == TCMU_SG_TO_DATA_AREA)
752 memcpy(data_addr, sg_iter.addr, cp_len);
753 else
754 memcpy(sg_iter.addr, data_addr, cp_len);
755
756 data_len -= cp_len;
757 page_remaining -= cp_len;
758 sg_iter.consumed = cp_len;
759 }
760 sg_miter_stop(&sg_iter);
761
762 kunmap_atomic(data_page_start);
763 if (direction == TCMU_SG_TO_DATA_AREA)
764 flush_dcache_page(page);
765 }
766 }
767 }
768
scatter_data_area(struct tcmu_dev * udev,struct tcmu_cmd * tcmu_cmd,struct iovec ** iov)769 static void scatter_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
770 struct iovec **iov)
771 {
772 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
773
774 tcmu_copy_data(udev, tcmu_cmd, TCMU_SG_TO_DATA_AREA, se_cmd->t_data_sg,
775 se_cmd->t_data_nents, iov, se_cmd->data_length);
776 }
777
gather_data_area(struct tcmu_dev * udev,struct tcmu_cmd * tcmu_cmd,bool bidi,uint32_t read_len)778 static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *tcmu_cmd,
779 bool bidi, uint32_t read_len)
780 {
781 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
782 struct scatterlist *data_sg;
783 unsigned int data_nents;
784
785 if (!bidi) {
786 data_sg = se_cmd->t_data_sg;
787 data_nents = se_cmd->t_data_nents;
788 } else {
789 /*
790 * For bidi case, the first count blocks are for Data-Out
791 * buffer blocks, and before gathering the Data-In buffer
792 * the Data-Out buffer blocks should be skipped.
793 */
794 tcmu_cmd_set_dbi_cur(tcmu_cmd,
795 tcmu_cmd->dbi_cnt - tcmu_cmd->dbi_bidi_cnt);
796
797 data_sg = se_cmd->t_bidi_data_sg;
798 data_nents = se_cmd->t_bidi_data_nents;
799 }
800
801 tcmu_copy_data(udev, tcmu_cmd, TCMU_DATA_AREA_TO_SG, data_sg,
802 data_nents, NULL, read_len);
803 }
804
spc_bitmap_free(unsigned long * bitmap,uint32_t thresh)805 static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
806 {
807 return thresh - bitmap_weight(bitmap, thresh);
808 }
809
810 /*
811 * We can't queue a command until we have space available on the cmd ring.
812 *
813 * Called with ring lock held.
814 */
is_ring_space_avail(struct tcmu_dev * udev,size_t cmd_size)815 static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size)
816 {
817 struct tcmu_mailbox *mb = udev->mb_addr;
818 size_t space, cmd_needed;
819 u32 cmd_head;
820
821 tcmu_flush_dcache_range(mb, sizeof(*mb));
822
823 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
824
825 /*
826 * If cmd end-of-ring space is too small then we need space for a NOP plus
827 * original cmd - cmds are internally contiguous.
828 */
829 if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
830 cmd_needed = cmd_size;
831 else
832 cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
833
834 space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
835 if (space < cmd_needed) {
836 pr_debug("no cmd space: %u %u %u\n", cmd_head,
837 udev->cmdr_last_cleaned, udev->cmdr_size);
838 return false;
839 }
840 return true;
841 }
842
843 /*
844 * We have to allocate data buffers before we can queue a command.
845 * Returns -1 on error (not enough space) or number of needed iovs on success
846 *
847 * Called with ring lock held.
848 */
tcmu_alloc_data_space(struct tcmu_dev * udev,struct tcmu_cmd * cmd,int * iov_bidi_cnt)849 static int tcmu_alloc_data_space(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
850 int *iov_bidi_cnt)
851 {
852 int space, iov_cnt = 0, ret = 0;
853
854 if (!cmd->dbi_cnt)
855 goto wr_iov_cnts;
856
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 < cmd->dbi_cnt) {
860 unsigned long blocks_left =
861 (udev->max_blocks - udev->dbi_thresh) + space;
862
863 if (blocks_left < cmd->dbi_cnt) {
864 pr_debug("no data space: only %lu available, but ask for %u\n",
865 blocks_left * udev->data_blk_size,
866 cmd->dbi_cnt * udev->data_blk_size);
867 return -1;
868 }
869
870 udev->dbi_thresh += cmd->dbi_cnt;
871 if (udev->dbi_thresh > udev->max_blocks)
872 udev->dbi_thresh = udev->max_blocks;
873 }
874
875 iov_cnt = tcmu_get_empty_blocks(udev, cmd, cmd->se_cmd->data_length);
876 if (iov_cnt < 0)
877 return -1;
878
879 if (cmd->dbi_bidi_cnt) {
880 ret = tcmu_get_empty_blocks(udev, cmd, cmd->data_len_bidi);
881 if (ret < 0)
882 return -1;
883 }
884 wr_iov_cnts:
885 *iov_bidi_cnt = ret;
886 return iov_cnt + ret;
887 }
888
tcmu_cmd_get_base_cmd_size(size_t iov_cnt)889 static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
890 {
891 return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
892 sizeof(struct tcmu_cmd_entry));
893 }
894
tcmu_cmd_get_cmd_size(struct tcmu_cmd * tcmu_cmd,size_t base_command_size)895 static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
896 size_t base_command_size)
897 {
898 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
899 size_t command_size;
900
901 command_size = base_command_size +
902 round_up(scsi_command_size(se_cmd->t_task_cdb),
903 TCMU_OP_ALIGN_SIZE);
904
905 WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
906
907 return command_size;
908 }
909
tcmu_setup_cmd_timer(struct tcmu_cmd * tcmu_cmd,unsigned int tmo,struct timer_list * timer)910 static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
911 struct timer_list *timer)
912 {
913 if (!tmo)
914 return;
915
916 tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
917 if (!timer_pending(timer))
918 mod_timer(timer, tcmu_cmd->deadline);
919
920 pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd,
921 tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC);
922 }
923
add_to_qfull_queue(struct tcmu_cmd * tcmu_cmd)924 static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
925 {
926 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
927 unsigned int tmo;
928
929 /*
930 * For backwards compat if qfull_time_out is not set use
931 * cmd_time_out and if that's not set use the default time out.
932 */
933 if (!udev->qfull_time_out)
934 return -ETIMEDOUT;
935 else if (udev->qfull_time_out > 0)
936 tmo = udev->qfull_time_out;
937 else if (udev->cmd_time_out)
938 tmo = udev->cmd_time_out;
939 else
940 tmo = TCMU_TIME_OUT;
941
942 tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
943
944 list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
945 pr_debug("adding cmd %p on dev %s to ring space wait queue\n",
946 tcmu_cmd, udev->name);
947 return 0;
948 }
949
ring_insert_padding(struct tcmu_dev * udev,size_t cmd_size)950 static uint32_t ring_insert_padding(struct tcmu_dev *udev, size_t cmd_size)
951 {
952 struct tcmu_cmd_entry_hdr *hdr;
953 struct tcmu_mailbox *mb = udev->mb_addr;
954 uint32_t cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
955
956 /* Insert a PAD if end-of-ring space is too small */
957 if (head_to_end(cmd_head, udev->cmdr_size) < cmd_size) {
958 size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
959
960 hdr = udev->cmdr + cmd_head;
961 tcmu_hdr_set_op(&hdr->len_op, TCMU_OP_PAD);
962 tcmu_hdr_set_len(&hdr->len_op, pad_size);
963 hdr->cmd_id = 0; /* not used for PAD */
964 hdr->kflags = 0;
965 hdr->uflags = 0;
966 tcmu_flush_dcache_range(hdr, sizeof(*hdr));
967
968 UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
969 tcmu_flush_dcache_range(mb, sizeof(*mb));
970
971 cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
972 WARN_ON(cmd_head != 0);
973 }
974
975 return cmd_head;
976 }
977
tcmu_unplug_device(struct se_dev_plug * se_plug)978 static void tcmu_unplug_device(struct se_dev_plug *se_plug)
979 {
980 struct se_device *se_dev = se_plug->se_dev;
981 struct tcmu_dev *udev = TCMU_DEV(se_dev);
982
983 clear_bit(TCM_DEV_BIT_PLUGGED, &udev->flags);
984 uio_event_notify(&udev->uio_info);
985 }
986
tcmu_plug_device(struct se_device * se_dev)987 static struct se_dev_plug *tcmu_plug_device(struct se_device *se_dev)
988 {
989 struct tcmu_dev *udev = TCMU_DEV(se_dev);
990
991 if (!test_and_set_bit(TCM_DEV_BIT_PLUGGED, &udev->flags))
992 return &udev->se_plug;
993
994 return NULL;
995 }
996
997 /**
998 * queue_cmd_ring - queue cmd to ring or internally
999 * @tcmu_cmd: cmd to queue
1000 * @scsi_err: TCM error code if failure (-1) returned.
1001 *
1002 * Returns:
1003 * -1 we cannot queue internally or to the ring.
1004 * 0 success
1005 * 1 internally queued to wait for ring memory to free.
1006 */
queue_cmd_ring(struct tcmu_cmd * tcmu_cmd,sense_reason_t * scsi_err)1007 static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
1008 {
1009 struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
1010 struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
1011 size_t base_command_size, command_size;
1012 struct tcmu_mailbox *mb = udev->mb_addr;
1013 struct tcmu_cmd_entry *entry;
1014 struct iovec *iov;
1015 int iov_cnt, iov_bidi_cnt;
1016 uint32_t cmd_id, cmd_head;
1017 uint64_t cdb_off;
1018 uint32_t blk_size = udev->data_blk_size;
1019 /* size of data buffer needed */
1020 size_t data_length = (size_t)tcmu_cmd->dbi_cnt * blk_size;
1021
1022 *scsi_err = TCM_NO_SENSE;
1023
1024 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
1025 *scsi_err = TCM_LUN_BUSY;
1026 return -1;
1027 }
1028
1029 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1030 *scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1031 return -1;
1032 }
1033
1034 if (!list_empty(&udev->qfull_queue))
1035 goto queue;
1036
1037 if (data_length > (size_t)udev->max_blocks * blk_size) {
1038 pr_warn("TCMU: Request of size %zu is too big for %zu data area\n",
1039 data_length, (size_t)udev->max_blocks * blk_size);
1040 *scsi_err = TCM_INVALID_CDB_FIELD;
1041 return -1;
1042 }
1043
1044 iov_cnt = tcmu_alloc_data_space(udev, tcmu_cmd, &iov_bidi_cnt);
1045 if (iov_cnt < 0)
1046 goto free_and_queue;
1047
1048 /*
1049 * Must be a certain minimum size for response sense info, but
1050 * also may be larger if the iov array is large.
1051 */
1052 base_command_size = tcmu_cmd_get_base_cmd_size(iov_cnt);
1053 command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
1054
1055 if (command_size > (udev->cmdr_size / 2)) {
1056 pr_warn("TCMU: Request of size %zu is too big for %u cmd ring\n",
1057 command_size, udev->cmdr_size);
1058 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1059 *scsi_err = TCM_INVALID_CDB_FIELD;
1060 return -1;
1061 }
1062
1063 if (!is_ring_space_avail(udev, command_size))
1064 /*
1065 * Don't leave commands partially setup because the unmap
1066 * thread might need the blocks to make forward progress.
1067 */
1068 goto free_and_queue;
1069
1070 if (xa_alloc(&udev->commands, &cmd_id, tcmu_cmd, XA_LIMIT(1, 0xffff),
1071 GFP_NOWAIT) < 0) {
1072 pr_err("tcmu: Could not allocate cmd id.\n");
1073
1074 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
1075 *scsi_err = TCM_OUT_OF_RESOURCES;
1076 return -1;
1077 }
1078 tcmu_cmd->cmd_id = cmd_id;
1079
1080 pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id,
1081 tcmu_cmd, udev->name);
1082
1083 cmd_head = ring_insert_padding(udev, command_size);
1084
1085 entry = udev->cmdr + cmd_head;
1086 memset(entry, 0, command_size);
1087 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
1088
1089 /* prepare iov list and copy data to data area if necessary */
1090 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1091 iov = &entry->req.iov[0];
1092
1093 if (se_cmd->data_direction == DMA_TO_DEVICE ||
1094 se_cmd->se_cmd_flags & SCF_BIDI)
1095 scatter_data_area(udev, tcmu_cmd, &iov);
1096 else
1097 tcmu_setup_iovs(udev, tcmu_cmd, &iov, se_cmd->data_length);
1098
1099 entry->req.iov_cnt = iov_cnt - iov_bidi_cnt;
1100
1101 /* Handle BIDI commands */
1102 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1103 iov++;
1104 tcmu_setup_iovs(udev, tcmu_cmd, &iov, tcmu_cmd->data_len_bidi);
1105 entry->req.iov_bidi_cnt = iov_bidi_cnt;
1106 }
1107
1108 tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer);
1109
1110 entry->hdr.cmd_id = tcmu_cmd->cmd_id;
1111
1112 tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
1113
1114 /* All offsets relative to mb_addr, not start of entry! */
1115 cdb_off = CMDR_OFF + cmd_head + base_command_size;
1116 memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
1117 entry->req.cdb_off = cdb_off;
1118 tcmu_flush_dcache_range(entry, command_size);
1119
1120 UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
1121 tcmu_flush_dcache_range(mb, sizeof(*mb));
1122
1123 list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
1124
1125 if (!test_bit(TCM_DEV_BIT_PLUGGED, &udev->flags))
1126 uio_event_notify(&udev->uio_info);
1127
1128 return 0;
1129
1130 free_and_queue:
1131 tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
1132 tcmu_cmd_reset_dbi_cur(tcmu_cmd);
1133
1134 queue:
1135 if (add_to_qfull_queue(tcmu_cmd)) {
1136 *scsi_err = TCM_OUT_OF_RESOURCES;
1137 return -1;
1138 }
1139
1140 return 1;
1141 }
1142
1143 /**
1144 * queue_tmr_ring - queue tmr info to ring or internally
1145 * @udev: related tcmu_dev
1146 * @tmr: tcmu_tmr containing tmr info to queue
1147 *
1148 * Returns:
1149 * 0 success
1150 * 1 internally queued to wait for ring memory to free.
1151 */
1152 static int
queue_tmr_ring(struct tcmu_dev * udev,struct tcmu_tmr * tmr)1153 queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr)
1154 {
1155 struct tcmu_tmr_entry *entry;
1156 int cmd_size;
1157 int id_list_sz;
1158 struct tcmu_mailbox *mb = udev->mb_addr;
1159 uint32_t cmd_head;
1160
1161 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
1162 goto out_free;
1163
1164 id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
1165 cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
1166
1167 if (!list_empty(&udev->tmr_queue) ||
1168 !is_ring_space_avail(udev, cmd_size)) {
1169 list_add_tail(&tmr->queue_entry, &udev->tmr_queue);
1170 pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
1171 tmr, udev->name);
1172 return 1;
1173 }
1174
1175 cmd_head = ring_insert_padding(udev, cmd_size);
1176
1177 entry = udev->cmdr + cmd_head;
1178 memset(entry, 0, cmd_size);
1179 tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
1180 tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
1181 entry->tmr_type = tmr->tmr_type;
1182 entry->cmd_cnt = tmr->tmr_cmd_cnt;
1183 memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
1184 tcmu_flush_dcache_range(entry, cmd_size);
1185
1186 UPDATE_HEAD(mb->cmd_head, cmd_size, udev->cmdr_size);
1187 tcmu_flush_dcache_range(mb, sizeof(*mb));
1188
1189 uio_event_notify(&udev->uio_info);
1190
1191 out_free:
1192 kfree(tmr);
1193
1194 return 0;
1195 }
1196
1197 static sense_reason_t
tcmu_queue_cmd(struct se_cmd * se_cmd)1198 tcmu_queue_cmd(struct se_cmd *se_cmd)
1199 {
1200 struct se_device *se_dev = se_cmd->se_dev;
1201 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1202 struct tcmu_cmd *tcmu_cmd;
1203 sense_reason_t scsi_ret = TCM_CHECK_CONDITION_ABORT_CMD;
1204 int ret = -1;
1205
1206 tcmu_cmd = tcmu_alloc_cmd(se_cmd);
1207 if (!tcmu_cmd)
1208 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1209
1210 mutex_lock(&udev->cmdr_lock);
1211 if (!(se_cmd->transport_state & CMD_T_ABORTED))
1212 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1213 if (ret < 0)
1214 tcmu_free_cmd(tcmu_cmd);
1215 else
1216 se_cmd->priv = tcmu_cmd;
1217 mutex_unlock(&udev->cmdr_lock);
1218 return scsi_ret;
1219 }
1220
tcmu_set_next_deadline(struct list_head * queue,struct timer_list * timer)1221 static void tcmu_set_next_deadline(struct list_head *queue,
1222 struct timer_list *timer)
1223 {
1224 struct tcmu_cmd *cmd;
1225
1226 if (!list_empty(queue)) {
1227 cmd = list_first_entry(queue, struct tcmu_cmd, queue_entry);
1228 mod_timer(timer, cmd->deadline);
1229 } else
1230 del_timer(timer);
1231 }
1232
1233 static int
tcmu_tmr_type(enum tcm_tmreq_table tmf)1234 tcmu_tmr_type(enum tcm_tmreq_table tmf)
1235 {
1236 switch (tmf) {
1237 case TMR_ABORT_TASK: return TCMU_TMR_ABORT_TASK;
1238 case TMR_ABORT_TASK_SET: return TCMU_TMR_ABORT_TASK_SET;
1239 case TMR_CLEAR_ACA: return TCMU_TMR_CLEAR_ACA;
1240 case TMR_CLEAR_TASK_SET: return TCMU_TMR_CLEAR_TASK_SET;
1241 case TMR_LUN_RESET: return TCMU_TMR_LUN_RESET;
1242 case TMR_TARGET_WARM_RESET: return TCMU_TMR_TARGET_WARM_RESET;
1243 case TMR_TARGET_COLD_RESET: return TCMU_TMR_TARGET_COLD_RESET;
1244 case TMR_LUN_RESET_PRO: return TCMU_TMR_LUN_RESET_PRO;
1245 default: return TCMU_TMR_UNKNOWN;
1246 }
1247 }
1248
1249 static void
tcmu_tmr_notify(struct se_device * se_dev,enum tcm_tmreq_table tmf,struct list_head * cmd_list)1250 tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
1251 struct list_head *cmd_list)
1252 {
1253 int i = 0, cmd_cnt = 0;
1254 bool unqueued = false;
1255 uint16_t *cmd_ids = NULL;
1256 struct tcmu_cmd *cmd;
1257 struct se_cmd *se_cmd;
1258 struct tcmu_tmr *tmr;
1259 struct tcmu_dev *udev = TCMU_DEV(se_dev);
1260
1261 mutex_lock(&udev->cmdr_lock);
1262
1263 /* First we check for aborted commands in qfull_queue */
1264 list_for_each_entry(se_cmd, cmd_list, state_list) {
1265 i++;
1266 if (!se_cmd->priv)
1267 continue;
1268 cmd = se_cmd->priv;
1269 /* Commands on qfull queue have no id yet */
1270 if (cmd->cmd_id) {
1271 cmd_cnt++;
1272 continue;
1273 }
1274 pr_debug("Removing aborted command %p from queue on dev %s.\n",
1275 cmd, udev->name);
1276
1277 list_del_init(&cmd->queue_entry);
1278 tcmu_free_cmd(cmd);
1279 se_cmd->priv = NULL;
1280 target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
1281 unqueued = true;
1282 }
1283 if (unqueued)
1284 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1285
1286 if (!test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags))
1287 goto unlock;
1288
1289 pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
1290 tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
1291
1292 tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_NOIO);
1293 if (!tmr)
1294 goto unlock;
1295
1296 tmr->tmr_type = tcmu_tmr_type(tmf);
1297 tmr->tmr_cmd_cnt = cmd_cnt;
1298
1299 if (cmd_cnt != 0) {
1300 cmd_cnt = 0;
1301 list_for_each_entry(se_cmd, cmd_list, state_list) {
1302 if (!se_cmd->priv)
1303 continue;
1304 cmd = se_cmd->priv;
1305 if (cmd->cmd_id)
1306 tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
1307 }
1308 }
1309
1310 queue_tmr_ring(udev, tmr);
1311
1312 unlock:
1313 mutex_unlock(&udev->cmdr_lock);
1314 }
1315
tcmu_handle_completion(struct tcmu_cmd * cmd,struct tcmu_cmd_entry * entry)1316 static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
1317 {
1318 struct se_cmd *se_cmd = cmd->se_cmd;
1319 struct tcmu_dev *udev = cmd->tcmu_dev;
1320 bool read_len_valid = false;
1321 uint32_t read_len;
1322
1323 /*
1324 * cmd has been completed already from timeout, just reclaim
1325 * data area space and free cmd
1326 */
1327 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1328 WARN_ON_ONCE(se_cmd);
1329 goto out;
1330 }
1331
1332 list_del_init(&cmd->queue_entry);
1333
1334 tcmu_cmd_reset_dbi_cur(cmd);
1335
1336 if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
1337 pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
1338 cmd->se_cmd);
1339 entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
1340 goto done;
1341 }
1342
1343 read_len = se_cmd->data_length;
1344 if (se_cmd->data_direction == DMA_FROM_DEVICE &&
1345 (entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
1346 read_len_valid = true;
1347 if (entry->rsp.read_len < read_len)
1348 read_len = entry->rsp.read_len;
1349 }
1350
1351 if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
1352 transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
1353 if (!read_len_valid )
1354 goto done;
1355 else
1356 se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
1357 }
1358 if (se_cmd->se_cmd_flags & SCF_BIDI) {
1359 /* Get Data-In buffer before clean up */
1360 gather_data_area(udev, cmd, true, read_len);
1361 } else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
1362 gather_data_area(udev, cmd, false, read_len);
1363 } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
1364 /* TODO: */
1365 } else if (se_cmd->data_direction != DMA_NONE) {
1366 pr_warn("TCMU: data direction was %d!\n",
1367 se_cmd->data_direction);
1368 }
1369
1370 done:
1371 se_cmd->priv = NULL;
1372 if (read_len_valid) {
1373 pr_debug("read_len = %d\n", read_len);
1374 target_complete_cmd_with_length(cmd->se_cmd,
1375 entry->rsp.scsi_status, read_len);
1376 } else
1377 target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
1378
1379 out:
1380 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
1381 tcmu_free_cmd(cmd);
1382 }
1383
tcmu_run_tmr_queue(struct tcmu_dev * udev)1384 static int tcmu_run_tmr_queue(struct tcmu_dev *udev)
1385 {
1386 struct tcmu_tmr *tmr, *tmp;
1387 LIST_HEAD(tmrs);
1388
1389 if (list_empty(&udev->tmr_queue))
1390 return 1;
1391
1392 pr_debug("running %s's tmr queue\n", udev->name);
1393
1394 list_splice_init(&udev->tmr_queue, &tmrs);
1395
1396 list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
1397 list_del_init(&tmr->queue_entry);
1398
1399 pr_debug("removing tmr %p on dev %s from queue\n",
1400 tmr, udev->name);
1401
1402 if (queue_tmr_ring(udev, tmr)) {
1403 pr_debug("ran out of space during tmr queue run\n");
1404 /*
1405 * tmr was requeued, so just put all tmrs back in
1406 * the queue
1407 */
1408 list_splice_tail(&tmrs, &udev->tmr_queue);
1409 return 0;
1410 }
1411 }
1412
1413 return 1;
1414 }
1415
tcmu_handle_completions(struct tcmu_dev * udev)1416 static bool tcmu_handle_completions(struct tcmu_dev *udev)
1417 {
1418 struct tcmu_mailbox *mb;
1419 struct tcmu_cmd *cmd;
1420 bool free_space = false;
1421
1422 if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
1423 pr_err("ring broken, not handling completions\n");
1424 return 0;
1425 }
1426
1427 mb = udev->mb_addr;
1428 tcmu_flush_dcache_range(mb, sizeof(*mb));
1429
1430 while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
1431
1432 struct tcmu_cmd_entry *entry = udev->cmdr + udev->cmdr_last_cleaned;
1433
1434 /*
1435 * Flush max. up to end of cmd ring since current entry might
1436 * be a padding that is shorter than sizeof(*entry)
1437 */
1438 size_t ring_left = head_to_end(udev->cmdr_last_cleaned,
1439 udev->cmdr_size);
1440 tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
1441 ring_left : sizeof(*entry));
1442
1443 free_space = true;
1444
1445 if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
1446 tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
1447 UPDATE_HEAD(udev->cmdr_last_cleaned,
1448 tcmu_hdr_get_len(entry->hdr.len_op),
1449 udev->cmdr_size);
1450 continue;
1451 }
1452 WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
1453
1454 cmd = xa_erase(&udev->commands, entry->hdr.cmd_id);
1455 if (!cmd) {
1456 pr_err("cmd_id %u not found, ring is broken\n",
1457 entry->hdr.cmd_id);
1458 set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
1459 return false;
1460 }
1461
1462 tcmu_handle_completion(cmd, entry);
1463
1464 UPDATE_HEAD(udev->cmdr_last_cleaned,
1465 tcmu_hdr_get_len(entry->hdr.len_op),
1466 udev->cmdr_size);
1467 }
1468 if (free_space)
1469 free_space = tcmu_run_tmr_queue(udev);
1470
1471 if (atomic_read(&global_page_count) > tcmu_global_max_pages &&
1472 xa_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
1473 /*
1474 * Allocated blocks exceeded global block limit, currently no
1475 * more pending or waiting commands so try to reclaim blocks.
1476 */
1477 schedule_delayed_work(&tcmu_unmap_work, 0);
1478 }
1479 if (udev->cmd_time_out)
1480 tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
1481
1482 return free_space;
1483 }
1484
tcmu_check_expired_ring_cmd(struct tcmu_cmd * cmd)1485 static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
1486 {
1487 struct se_cmd *se_cmd;
1488
1489 if (!time_after_eq(jiffies, cmd->deadline))
1490 return;
1491
1492 set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
1493 list_del_init(&cmd->queue_entry);
1494 se_cmd = cmd->se_cmd;
1495 se_cmd->priv = NULL;
1496 cmd->se_cmd = NULL;
1497
1498 pr_debug("Timing out inflight cmd %u on dev %s.\n",
1499 cmd->cmd_id, cmd->tcmu_dev->name);
1500
1501 target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION);
1502 }
1503
tcmu_check_expired_queue_cmd(struct tcmu_cmd * cmd)1504 static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd)
1505 {
1506 struct se_cmd *se_cmd;
1507
1508 if (!time_after_eq(jiffies, cmd->deadline))
1509 return;
1510
1511 pr_debug("Timing out queued cmd %p on dev %s.\n",
1512 cmd, cmd->tcmu_dev->name);
1513
1514 list_del_init(&cmd->queue_entry);
1515 se_cmd = cmd->se_cmd;
1516 tcmu_free_cmd(cmd);
1517
1518 se_cmd->priv = NULL;
1519 target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL);
1520 }
1521
tcmu_device_timedout(struct tcmu_dev * udev)1522 static void tcmu_device_timedout(struct tcmu_dev *udev)
1523 {
1524 spin_lock(&timed_out_udevs_lock);
1525 if (list_empty(&udev->timedout_entry))
1526 list_add_tail(&udev->timedout_entry, &timed_out_udevs);
1527 spin_unlock(&timed_out_udevs_lock);
1528
1529 schedule_delayed_work(&tcmu_unmap_work, 0);
1530 }
1531
tcmu_cmd_timedout(struct timer_list * t)1532 static void tcmu_cmd_timedout(struct timer_list *t)
1533 {
1534 struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
1535
1536 pr_debug("%s cmd timeout has expired\n", udev->name);
1537 tcmu_device_timedout(udev);
1538 }
1539
tcmu_qfull_timedout(struct timer_list * t)1540 static void tcmu_qfull_timedout(struct timer_list *t)
1541 {
1542 struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
1543
1544 pr_debug("%s qfull timeout has expired\n", udev->name);
1545 tcmu_device_timedout(udev);
1546 }
1547
tcmu_attach_hba(struct se_hba * hba,u32 host_id)1548 static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
1549 {
1550 struct tcmu_hba *tcmu_hba;
1551
1552 tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
1553 if (!tcmu_hba)
1554 return -ENOMEM;
1555
1556 tcmu_hba->host_id = host_id;
1557 hba->hba_ptr = tcmu_hba;
1558
1559 return 0;
1560 }
1561
tcmu_detach_hba(struct se_hba * hba)1562 static void tcmu_detach_hba(struct se_hba *hba)
1563 {
1564 kfree(hba->hba_ptr);
1565 hba->hba_ptr = NULL;
1566 }
1567
tcmu_alloc_device(struct se_hba * hba,const char * name)1568 static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
1569 {
1570 struct tcmu_dev *udev;
1571
1572 udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
1573 if (!udev)
1574 return NULL;
1575 kref_init(&udev->kref);
1576
1577 udev->name = kstrdup(name, GFP_KERNEL);
1578 if (!udev->name) {
1579 kfree(udev);
1580 return NULL;
1581 }
1582
1583 udev->hba = hba;
1584 udev->cmd_time_out = TCMU_TIME_OUT;
1585 udev->qfull_time_out = -1;
1586
1587 udev->data_pages_per_blk = DATA_PAGES_PER_BLK_DEF;
1588 udev->max_blocks = DATA_AREA_PAGES_DEF / udev->data_pages_per_blk;
1589 udev->data_area_mb = TCMU_PAGES_TO_MBS(DATA_AREA_PAGES_DEF);
1590
1591 mutex_init(&udev->cmdr_lock);
1592
1593 INIT_LIST_HEAD(&udev->node);
1594 INIT_LIST_HEAD(&udev->timedout_entry);
1595 INIT_LIST_HEAD(&udev->qfull_queue);
1596 INIT_LIST_HEAD(&udev->tmr_queue);
1597 INIT_LIST_HEAD(&udev->inflight_queue);
1598 xa_init_flags(&udev->commands, XA_FLAGS_ALLOC1);
1599
1600 timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
1601 timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
1602
1603 xa_init(&udev->data_pages);
1604
1605 return &udev->se_dev;
1606 }
1607
tcmu_dev_call_rcu(struct rcu_head * p)1608 static void tcmu_dev_call_rcu(struct rcu_head *p)
1609 {
1610 struct se_device *dev = container_of(p, struct se_device, rcu_head);
1611 struct tcmu_dev *udev = TCMU_DEV(dev);
1612
1613 kfree(udev->uio_info.name);
1614 kfree(udev->name);
1615 kfree(udev);
1616 }
1617
tcmu_check_and_free_pending_cmd(struct tcmu_cmd * cmd)1618 static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
1619 {
1620 if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
1621 kmem_cache_free(tcmu_cmd_cache, cmd);
1622 return 0;
1623 }
1624 return -EINVAL;
1625 }
1626
tcmu_blocks_release(struct tcmu_dev * udev,unsigned long first,unsigned long last)1627 static u32 tcmu_blocks_release(struct tcmu_dev *udev, unsigned long first,
1628 unsigned long last)
1629 {
1630 XA_STATE(xas, &udev->data_pages, first * udev->data_pages_per_blk);
1631 struct page *page;
1632 u32 pages_freed = 0;
1633
1634 xas_lock(&xas);
1635 xas_for_each(&xas, page, (last + 1) * udev->data_pages_per_blk - 1) {
1636 xas_store(&xas, NULL);
1637 __free_page(page);
1638 pages_freed++;
1639 }
1640 xas_unlock(&xas);
1641
1642 atomic_sub(pages_freed, &global_page_count);
1643
1644 return pages_freed;
1645 }
1646
tcmu_remove_all_queued_tmr(struct tcmu_dev * udev)1647 static void tcmu_remove_all_queued_tmr(struct tcmu_dev *udev)
1648 {
1649 struct tcmu_tmr *tmr, *tmp;
1650
1651 list_for_each_entry_safe(tmr, tmp, &udev->tmr_queue, queue_entry) {
1652 list_del_init(&tmr->queue_entry);
1653 kfree(tmr);
1654 }
1655 }
1656
tcmu_dev_kref_release(struct kref * kref)1657 static void tcmu_dev_kref_release(struct kref *kref)
1658 {
1659 struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
1660 struct se_device *dev = &udev->se_dev;
1661 struct tcmu_cmd *cmd;
1662 bool all_expired = true;
1663 unsigned long i;
1664
1665 vfree(udev->mb_addr);
1666 udev->mb_addr = NULL;
1667
1668 spin_lock_bh(&timed_out_udevs_lock);
1669 if (!list_empty(&udev->timedout_entry))
1670 list_del(&udev->timedout_entry);
1671 spin_unlock_bh(&timed_out_udevs_lock);
1672
1673 /* Upper layer should drain all requests before calling this */
1674 mutex_lock(&udev->cmdr_lock);
1675 xa_for_each(&udev->commands, i, cmd) {
1676 if (tcmu_check_and_free_pending_cmd(cmd) != 0)
1677 all_expired = false;
1678 }
1679 /* There can be left over TMR cmds. Remove them. */
1680 tcmu_remove_all_queued_tmr(udev);
1681 if (!list_empty(&udev->qfull_queue))
1682 all_expired = false;
1683 xa_destroy(&udev->commands);
1684 WARN_ON(!all_expired);
1685
1686 tcmu_blocks_release(udev, 0, udev->dbi_max);
1687 bitmap_free(udev->data_bitmap);
1688 mutex_unlock(&udev->cmdr_lock);
1689
1690 pr_debug("dev_kref_release\n");
1691
1692 call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
1693 }
1694
run_qfull_queue(struct tcmu_dev * udev,bool fail)1695 static void run_qfull_queue(struct tcmu_dev *udev, bool fail)
1696 {
1697 struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
1698 LIST_HEAD(cmds);
1699 sense_reason_t scsi_ret;
1700 int ret;
1701
1702 if (list_empty(&udev->qfull_queue))
1703 return;
1704
1705 pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
1706
1707 list_splice_init(&udev->qfull_queue, &cmds);
1708
1709 list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
1710 list_del_init(&tcmu_cmd->queue_entry);
1711
1712 pr_debug("removing cmd %p on dev %s from queue\n",
1713 tcmu_cmd, udev->name);
1714
1715 if (fail) {
1716 /*
1717 * We were not able to even start the command, so
1718 * fail with busy to allow a retry in case runner
1719 * was only temporarily down. If the device is being
1720 * removed then LIO core will do the right thing and
1721 * fail the retry.
1722 */
1723 tcmu_cmd->se_cmd->priv = NULL;
1724 target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
1725 tcmu_free_cmd(tcmu_cmd);
1726 continue;
1727 }
1728
1729 ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
1730 if (ret < 0) {
1731 pr_debug("cmd %p on dev %s failed with %u\n",
1732 tcmu_cmd, udev->name, scsi_ret);
1733 /*
1734 * Ignore scsi_ret for now. target_complete_cmd
1735 * drops it.
1736 */
1737 tcmu_cmd->se_cmd->priv = NULL;
1738 target_complete_cmd(tcmu_cmd->se_cmd,
1739 SAM_STAT_CHECK_CONDITION);
1740 tcmu_free_cmd(tcmu_cmd);
1741 } else if (ret > 0) {
1742 pr_debug("ran out of space during cmdr queue run\n");
1743 /*
1744 * cmd was requeued, so just put all cmds back in
1745 * the queue
1746 */
1747 list_splice_tail(&cmds, &udev->qfull_queue);
1748 break;
1749 }
1750 }
1751
1752 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
1753 }
1754
tcmu_irqcontrol(struct uio_info * info,s32 irq_on)1755 static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
1756 {
1757 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1758
1759 mutex_lock(&udev->cmdr_lock);
1760 if (tcmu_handle_completions(udev))
1761 run_qfull_queue(udev, false);
1762 mutex_unlock(&udev->cmdr_lock);
1763
1764 return 0;
1765 }
1766
1767 /*
1768 * mmap code from uio.c. Copied here because we want to hook mmap()
1769 * and this stuff must come along.
1770 */
tcmu_find_mem_index(struct vm_area_struct * vma)1771 static int tcmu_find_mem_index(struct vm_area_struct *vma)
1772 {
1773 struct tcmu_dev *udev = vma->vm_private_data;
1774 struct uio_info *info = &udev->uio_info;
1775
1776 if (vma->vm_pgoff < MAX_UIO_MAPS) {
1777 if (info->mem[vma->vm_pgoff].size == 0)
1778 return -1;
1779 return (int)vma->vm_pgoff;
1780 }
1781 return -1;
1782 }
1783
tcmu_try_get_data_page(struct tcmu_dev * udev,uint32_t dpi)1784 static struct page *tcmu_try_get_data_page(struct tcmu_dev *udev, uint32_t dpi)
1785 {
1786 struct page *page;
1787
1788 mutex_lock(&udev->cmdr_lock);
1789 page = xa_load(&udev->data_pages, dpi);
1790 if (likely(page)) {
1791 mutex_unlock(&udev->cmdr_lock);
1792 return page;
1793 }
1794
1795 /*
1796 * Userspace messed up and passed in a address not in the
1797 * data iov passed to it.
1798 */
1799 pr_err("Invalid addr to data page mapping (dpi %u) on device %s\n",
1800 dpi, udev->name);
1801 mutex_unlock(&udev->cmdr_lock);
1802
1803 return NULL;
1804 }
1805
tcmu_vma_open(struct vm_area_struct * vma)1806 static void tcmu_vma_open(struct vm_area_struct *vma)
1807 {
1808 struct tcmu_dev *udev = vma->vm_private_data;
1809
1810 pr_debug("vma_open\n");
1811
1812 kref_get(&udev->kref);
1813 }
1814
tcmu_vma_close(struct vm_area_struct * vma)1815 static void tcmu_vma_close(struct vm_area_struct *vma)
1816 {
1817 struct tcmu_dev *udev = vma->vm_private_data;
1818
1819 pr_debug("vma_close\n");
1820
1821 /* release ref from tcmu_vma_open */
1822 kref_put(&udev->kref, tcmu_dev_kref_release);
1823 }
1824
tcmu_vma_fault(struct vm_fault * vmf)1825 static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
1826 {
1827 struct tcmu_dev *udev = vmf->vma->vm_private_data;
1828 struct uio_info *info = &udev->uio_info;
1829 struct page *page;
1830 unsigned long offset;
1831 void *addr;
1832
1833 int mi = tcmu_find_mem_index(vmf->vma);
1834 if (mi < 0)
1835 return VM_FAULT_SIGBUS;
1836
1837 /*
1838 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
1839 * to use mem[N].
1840 */
1841 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
1842
1843 if (offset < udev->data_off) {
1844 /* For the vmalloc()ed cmd area pages */
1845 addr = (void *)(unsigned long)info->mem[mi].addr + offset;
1846 page = vmalloc_to_page(addr);
1847 } else {
1848 uint32_t dpi;
1849
1850 /* For the dynamically growing data area pages */
1851 dpi = (offset - udev->data_off) / PAGE_SIZE;
1852 page = tcmu_try_get_data_page(udev, dpi);
1853 if (!page)
1854 return VM_FAULT_SIGBUS;
1855 }
1856
1857 get_page(page);
1858 vmf->page = page;
1859 return 0;
1860 }
1861
1862 static const struct vm_operations_struct tcmu_vm_ops = {
1863 .open = tcmu_vma_open,
1864 .close = tcmu_vma_close,
1865 .fault = tcmu_vma_fault,
1866 };
1867
tcmu_mmap(struct uio_info * info,struct vm_area_struct * vma)1868 static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
1869 {
1870 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1871
1872 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1873 vma->vm_ops = &tcmu_vm_ops;
1874
1875 vma->vm_private_data = udev;
1876
1877 /* Ensure the mmap is exactly the right size */
1878 if (vma_pages(vma) != udev->mmap_pages)
1879 return -EINVAL;
1880
1881 tcmu_vma_open(vma);
1882
1883 return 0;
1884 }
1885
tcmu_open(struct uio_info * info,struct inode * inode)1886 static int tcmu_open(struct uio_info *info, struct inode *inode)
1887 {
1888 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1889
1890 /* O_EXCL not supported for char devs, so fake it? */
1891 if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
1892 return -EBUSY;
1893
1894 udev->inode = inode;
1895
1896 pr_debug("open\n");
1897
1898 return 0;
1899 }
1900
tcmu_release(struct uio_info * info,struct inode * inode)1901 static int tcmu_release(struct uio_info *info, struct inode *inode)
1902 {
1903 struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
1904
1905 clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
1906
1907 pr_debug("close\n");
1908
1909 return 0;
1910 }
1911
tcmu_init_genl_cmd_reply(struct tcmu_dev * udev,int cmd)1912 static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
1913 {
1914 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1915
1916 if (!tcmu_kern_cmd_reply_supported)
1917 return 0;
1918
1919 if (udev->nl_reply_supported <= 0)
1920 return 0;
1921
1922 mutex_lock(&tcmu_nl_cmd_mutex);
1923
1924 if (tcmu_netlink_blocked) {
1925 mutex_unlock(&tcmu_nl_cmd_mutex);
1926 pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
1927 udev->name);
1928 return -EAGAIN;
1929 }
1930
1931 if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
1932 mutex_unlock(&tcmu_nl_cmd_mutex);
1933 pr_warn("netlink cmd %d already executing on %s\n",
1934 nl_cmd->cmd, udev->name);
1935 return -EBUSY;
1936 }
1937
1938 memset(nl_cmd, 0, sizeof(*nl_cmd));
1939 nl_cmd->cmd = cmd;
1940 nl_cmd->udev = udev;
1941 init_completion(&nl_cmd->complete);
1942 INIT_LIST_HEAD(&nl_cmd->nl_list);
1943
1944 list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
1945
1946 mutex_unlock(&tcmu_nl_cmd_mutex);
1947 return 0;
1948 }
1949
tcmu_destroy_genl_cmd_reply(struct tcmu_dev * udev)1950 static void tcmu_destroy_genl_cmd_reply(struct tcmu_dev *udev)
1951 {
1952 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1953
1954 if (!tcmu_kern_cmd_reply_supported)
1955 return;
1956
1957 if (udev->nl_reply_supported <= 0)
1958 return;
1959
1960 mutex_lock(&tcmu_nl_cmd_mutex);
1961
1962 list_del(&nl_cmd->nl_list);
1963 memset(nl_cmd, 0, sizeof(*nl_cmd));
1964
1965 mutex_unlock(&tcmu_nl_cmd_mutex);
1966 }
1967
tcmu_wait_genl_cmd_reply(struct tcmu_dev * udev)1968 static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
1969 {
1970 struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
1971 int ret;
1972
1973 if (!tcmu_kern_cmd_reply_supported)
1974 return 0;
1975
1976 if (udev->nl_reply_supported <= 0)
1977 return 0;
1978
1979 pr_debug("sleeping for nl reply\n");
1980 wait_for_completion(&nl_cmd->complete);
1981
1982 mutex_lock(&tcmu_nl_cmd_mutex);
1983 nl_cmd->cmd = TCMU_CMD_UNSPEC;
1984 ret = nl_cmd->status;
1985 mutex_unlock(&tcmu_nl_cmd_mutex);
1986
1987 return ret;
1988 }
1989
tcmu_netlink_event_init(struct tcmu_dev * udev,enum tcmu_genl_cmd cmd,struct sk_buff ** buf,void ** hdr)1990 static int tcmu_netlink_event_init(struct tcmu_dev *udev,
1991 enum tcmu_genl_cmd cmd,
1992 struct sk_buff **buf, void **hdr)
1993 {
1994 struct sk_buff *skb;
1995 void *msg_header;
1996 int ret = -ENOMEM;
1997
1998 skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1999 if (!skb)
2000 return ret;
2001
2002 msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
2003 if (!msg_header)
2004 goto free_skb;
2005
2006 ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
2007 if (ret < 0)
2008 goto free_skb;
2009
2010 ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
2011 if (ret < 0)
2012 goto free_skb;
2013
2014 ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
2015 if (ret < 0)
2016 goto free_skb;
2017
2018 *buf = skb;
2019 *hdr = msg_header;
2020 return ret;
2021
2022 free_skb:
2023 nlmsg_free(skb);
2024 return ret;
2025 }
2026
tcmu_netlink_event_send(struct tcmu_dev * udev,enum tcmu_genl_cmd cmd,struct sk_buff * skb,void * msg_header)2027 static int tcmu_netlink_event_send(struct tcmu_dev *udev,
2028 enum tcmu_genl_cmd cmd,
2029 struct sk_buff *skb, void *msg_header)
2030 {
2031 int ret;
2032
2033 genlmsg_end(skb, msg_header);
2034
2035 ret = tcmu_init_genl_cmd_reply(udev, cmd);
2036 if (ret) {
2037 nlmsg_free(skb);
2038 return ret;
2039 }
2040
2041 ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
2042 TCMU_MCGRP_CONFIG, GFP_KERNEL);
2043
2044 /* Wait during an add as the listener may not be up yet */
2045 if (ret == 0 ||
2046 (ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
2047 return tcmu_wait_genl_cmd_reply(udev);
2048 else
2049 tcmu_destroy_genl_cmd_reply(udev);
2050
2051 return ret;
2052 }
2053
tcmu_send_dev_add_event(struct tcmu_dev * udev)2054 static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
2055 {
2056 struct sk_buff *skb = NULL;
2057 void *msg_header = NULL;
2058 int ret = 0;
2059
2060 ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
2061 &msg_header);
2062 if (ret < 0)
2063 return ret;
2064 return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
2065 msg_header);
2066 }
2067
tcmu_send_dev_remove_event(struct tcmu_dev * udev)2068 static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
2069 {
2070 struct sk_buff *skb = NULL;
2071 void *msg_header = NULL;
2072 int ret = 0;
2073
2074 ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
2075 &skb, &msg_header);
2076 if (ret < 0)
2077 return ret;
2078 return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
2079 skb, msg_header);
2080 }
2081
tcmu_update_uio_info(struct tcmu_dev * udev)2082 static int tcmu_update_uio_info(struct tcmu_dev *udev)
2083 {
2084 struct tcmu_hba *hba = udev->hba->hba_ptr;
2085 struct uio_info *info;
2086 char *str;
2087
2088 info = &udev->uio_info;
2089
2090 if (udev->dev_config[0])
2091 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s/%s", hba->host_id,
2092 udev->name, udev->dev_config);
2093 else
2094 str = kasprintf(GFP_KERNEL, "tcm-user/%u/%s", hba->host_id,
2095 udev->name);
2096 if (!str)
2097 return -ENOMEM;
2098
2099 /* If the old string exists, free it */
2100 kfree(info->name);
2101 info->name = str;
2102
2103 return 0;
2104 }
2105
tcmu_configure_device(struct se_device * dev)2106 static int tcmu_configure_device(struct se_device *dev)
2107 {
2108 struct tcmu_dev *udev = TCMU_DEV(dev);
2109 struct uio_info *info;
2110 struct tcmu_mailbox *mb;
2111 size_t data_size;
2112 int ret = 0;
2113
2114 ret = tcmu_update_uio_info(udev);
2115 if (ret)
2116 return ret;
2117
2118 info = &udev->uio_info;
2119
2120 mutex_lock(&udev->cmdr_lock);
2121 udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
2122 mutex_unlock(&udev->cmdr_lock);
2123 if (!udev->data_bitmap) {
2124 ret = -ENOMEM;
2125 goto err_bitmap_alloc;
2126 }
2127
2128 mb = vzalloc(MB_CMDR_SIZE);
2129 if (!mb) {
2130 ret = -ENOMEM;
2131 goto err_vzalloc;
2132 }
2133
2134 /* mailbox fits in first part of CMDR space */
2135 udev->mb_addr = mb;
2136 udev->cmdr = (void *)mb + CMDR_OFF;
2137 udev->cmdr_size = CMDR_SIZE;
2138 udev->data_off = MB_CMDR_SIZE;
2139 data_size = TCMU_MBS_TO_PAGES(udev->data_area_mb) << PAGE_SHIFT;
2140 udev->mmap_pages = (data_size + MB_CMDR_SIZE) >> PAGE_SHIFT;
2141 udev->data_blk_size = udev->data_pages_per_blk * PAGE_SIZE;
2142 udev->dbi_thresh = 0; /* Default in Idle state */
2143
2144 /* Initialise the mailbox of the ring buffer */
2145 mb->version = TCMU_MAILBOX_VERSION;
2146 mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
2147 TCMU_MAILBOX_FLAG_CAP_READ_LEN |
2148 TCMU_MAILBOX_FLAG_CAP_TMR;
2149 mb->cmdr_off = CMDR_OFF;
2150 mb->cmdr_size = udev->cmdr_size;
2151
2152 WARN_ON(!PAGE_ALIGNED(udev->data_off));
2153 WARN_ON(data_size % PAGE_SIZE);
2154
2155 info->version = __stringify(TCMU_MAILBOX_VERSION);
2156
2157 info->mem[0].name = "tcm-user command & data buffer";
2158 info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
2159 info->mem[0].size = data_size + MB_CMDR_SIZE;
2160 info->mem[0].memtype = UIO_MEM_NONE;
2161
2162 info->irqcontrol = tcmu_irqcontrol;
2163 info->irq = UIO_IRQ_CUSTOM;
2164
2165 info->mmap = tcmu_mmap;
2166 info->open = tcmu_open;
2167 info->release = tcmu_release;
2168
2169 ret = uio_register_device(tcmu_root_device, info);
2170 if (ret)
2171 goto err_register;
2172
2173 /* User can set hw_block_size before enable the device */
2174 if (dev->dev_attrib.hw_block_size == 0)
2175 dev->dev_attrib.hw_block_size = 512;
2176 /* Other attributes can be configured in userspace */
2177 if (!dev->dev_attrib.hw_max_sectors)
2178 dev->dev_attrib.hw_max_sectors = 128;
2179 if (!dev->dev_attrib.emulate_write_cache)
2180 dev->dev_attrib.emulate_write_cache = 0;
2181 dev->dev_attrib.hw_queue_depth = 128;
2182
2183 /* If user didn't explicitly disable netlink reply support, use
2184 * module scope setting.
2185 */
2186 if (udev->nl_reply_supported >= 0)
2187 udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
2188
2189 /*
2190 * Get a ref incase userspace does a close on the uio device before
2191 * LIO has initiated tcmu_free_device.
2192 */
2193 kref_get(&udev->kref);
2194
2195 ret = tcmu_send_dev_add_event(udev);
2196 if (ret)
2197 goto err_netlink;
2198
2199 mutex_lock(&root_udev_mutex);
2200 list_add(&udev->node, &root_udev);
2201 mutex_unlock(&root_udev_mutex);
2202
2203 return 0;
2204
2205 err_netlink:
2206 kref_put(&udev->kref, tcmu_dev_kref_release);
2207 uio_unregister_device(&udev->uio_info);
2208 err_register:
2209 vfree(udev->mb_addr);
2210 udev->mb_addr = NULL;
2211 err_vzalloc:
2212 bitmap_free(udev->data_bitmap);
2213 udev->data_bitmap = NULL;
2214 err_bitmap_alloc:
2215 kfree(info->name);
2216 info->name = NULL;
2217
2218 return ret;
2219 }
2220
tcmu_free_device(struct se_device * dev)2221 static void tcmu_free_device(struct se_device *dev)
2222 {
2223 struct tcmu_dev *udev = TCMU_DEV(dev);
2224
2225 /* release ref from init */
2226 kref_put(&udev->kref, tcmu_dev_kref_release);
2227 }
2228
tcmu_destroy_device(struct se_device * dev)2229 static void tcmu_destroy_device(struct se_device *dev)
2230 {
2231 struct tcmu_dev *udev = TCMU_DEV(dev);
2232
2233 del_timer_sync(&udev->cmd_timer);
2234 del_timer_sync(&udev->qfull_timer);
2235
2236 mutex_lock(&root_udev_mutex);
2237 list_del(&udev->node);
2238 mutex_unlock(&root_udev_mutex);
2239
2240 tcmu_send_dev_remove_event(udev);
2241
2242 uio_unregister_device(&udev->uio_info);
2243
2244 /* release ref from configure */
2245 kref_put(&udev->kref, tcmu_dev_kref_release);
2246 }
2247
tcmu_unblock_dev(struct tcmu_dev * udev)2248 static void tcmu_unblock_dev(struct tcmu_dev *udev)
2249 {
2250 mutex_lock(&udev->cmdr_lock);
2251 clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
2252 mutex_unlock(&udev->cmdr_lock);
2253 }
2254
tcmu_block_dev(struct tcmu_dev * udev)2255 static void tcmu_block_dev(struct tcmu_dev *udev)
2256 {
2257 mutex_lock(&udev->cmdr_lock);
2258
2259 if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2260 goto unlock;
2261
2262 /* complete IO that has executed successfully */
2263 tcmu_handle_completions(udev);
2264 /* fail IO waiting to be queued */
2265 run_qfull_queue(udev, true);
2266
2267 unlock:
2268 mutex_unlock(&udev->cmdr_lock);
2269 }
2270
tcmu_reset_ring(struct tcmu_dev * udev,u8 err_level)2271 static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
2272 {
2273 struct tcmu_mailbox *mb;
2274 struct tcmu_cmd *cmd;
2275 unsigned long i;
2276
2277 mutex_lock(&udev->cmdr_lock);
2278
2279 xa_for_each(&udev->commands, i, cmd) {
2280 pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
2281 cmd->cmd_id, udev->name,
2282 test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
2283
2284 xa_erase(&udev->commands, i);
2285 if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
2286 WARN_ON(!cmd->se_cmd);
2287 list_del_init(&cmd->queue_entry);
2288 cmd->se_cmd->priv = NULL;
2289 if (err_level == 1) {
2290 /*
2291 * Userspace was not able to start the
2292 * command or it is retryable.
2293 */
2294 target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
2295 } else {
2296 /* hard failure */
2297 target_complete_cmd(cmd->se_cmd,
2298 SAM_STAT_CHECK_CONDITION);
2299 }
2300 }
2301 tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
2302 tcmu_free_cmd(cmd);
2303 }
2304
2305 mb = udev->mb_addr;
2306 tcmu_flush_dcache_range(mb, sizeof(*mb));
2307 pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
2308 mb->cmd_tail, mb->cmd_head);
2309
2310 udev->cmdr_last_cleaned = 0;
2311 mb->cmd_tail = 0;
2312 mb->cmd_head = 0;
2313 tcmu_flush_dcache_range(mb, sizeof(*mb));
2314 clear_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
2315
2316 del_timer(&udev->cmd_timer);
2317
2318 /*
2319 * ring is empty and qfull queue never contains aborted commands.
2320 * So TMRs in tmr queue do not contain relevant cmd_ids.
2321 * After a ring reset userspace should do a fresh start, so
2322 * even LUN RESET message is no longer relevant.
2323 * Therefore remove all TMRs from qfull queue
2324 */
2325 tcmu_remove_all_queued_tmr(udev);
2326
2327 run_qfull_queue(udev, false);
2328
2329 mutex_unlock(&udev->cmdr_lock);
2330 }
2331
2332 enum {
2333 Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
2334 Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_data_pages_per_blk,
2335 Opt_err,
2336 };
2337
2338 static match_table_t tokens = {
2339 {Opt_dev_config, "dev_config=%s"},
2340 {Opt_dev_size, "dev_size=%s"},
2341 {Opt_hw_block_size, "hw_block_size=%d"},
2342 {Opt_hw_max_sectors, "hw_max_sectors=%d"},
2343 {Opt_nl_reply_supported, "nl_reply_supported=%d"},
2344 {Opt_max_data_area_mb, "max_data_area_mb=%d"},
2345 {Opt_data_pages_per_blk, "data_pages_per_blk=%d"},
2346 {Opt_err, NULL}
2347 };
2348
tcmu_set_dev_attrib(substring_t * arg,u32 * dev_attrib)2349 static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
2350 {
2351 int val, ret;
2352
2353 ret = match_int(arg, &val);
2354 if (ret < 0) {
2355 pr_err("match_int() failed for dev attrib. Error %d.\n",
2356 ret);
2357 return ret;
2358 }
2359
2360 if (val <= 0) {
2361 pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
2362 val);
2363 return -EINVAL;
2364 }
2365 *dev_attrib = val;
2366 return 0;
2367 }
2368
tcmu_set_max_blocks_param(struct tcmu_dev * udev,substring_t * arg)2369 static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
2370 {
2371 int val, ret;
2372 uint32_t pages_per_blk = udev->data_pages_per_blk;
2373
2374 ret = match_int(arg, &val);
2375 if (ret < 0) {
2376 pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
2377 ret);
2378 return ret;
2379 }
2380 if (val <= 0) {
2381 pr_err("Invalid max_data_area %d.\n", val);
2382 return -EINVAL;
2383 }
2384 if (val > TCMU_PAGES_TO_MBS(tcmu_global_max_pages)) {
2385 pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
2386 val, TCMU_PAGES_TO_MBS(tcmu_global_max_pages));
2387 val = TCMU_PAGES_TO_MBS(tcmu_global_max_pages);
2388 }
2389 if (TCMU_MBS_TO_PAGES(val) < pages_per_blk) {
2390 pr_err("Invalid max_data_area %d (%zu pages): smaller than data_pages_per_blk (%u pages).\n",
2391 val, TCMU_MBS_TO_PAGES(val), pages_per_blk);
2392 return -EINVAL;
2393 }
2394
2395 mutex_lock(&udev->cmdr_lock);
2396 if (udev->data_bitmap) {
2397 pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
2398 ret = -EINVAL;
2399 goto unlock;
2400 }
2401
2402 udev->data_area_mb = val;
2403 udev->max_blocks = TCMU_MBS_TO_PAGES(val) / pages_per_blk;
2404
2405 unlock:
2406 mutex_unlock(&udev->cmdr_lock);
2407 return ret;
2408 }
2409
tcmu_set_data_pages_per_blk(struct tcmu_dev * udev,substring_t * arg)2410 static int tcmu_set_data_pages_per_blk(struct tcmu_dev *udev, substring_t *arg)
2411 {
2412 int val, ret;
2413
2414 ret = match_int(arg, &val);
2415 if (ret < 0) {
2416 pr_err("match_int() failed for data_pages_per_blk=. Error %d.\n",
2417 ret);
2418 return ret;
2419 }
2420
2421 if (val > TCMU_MBS_TO_PAGES(udev->data_area_mb)) {
2422 pr_err("Invalid data_pages_per_blk %d: greater than max_data_area_mb %d -> %zd pages).\n",
2423 val, udev->data_area_mb,
2424 TCMU_MBS_TO_PAGES(udev->data_area_mb));
2425 return -EINVAL;
2426 }
2427
2428 mutex_lock(&udev->cmdr_lock);
2429 if (udev->data_bitmap) {
2430 pr_err("Cannot set data_pages_per_blk after it has been enabled.\n");
2431 ret = -EINVAL;
2432 goto unlock;
2433 }
2434
2435 udev->data_pages_per_blk = val;
2436 udev->max_blocks = TCMU_MBS_TO_PAGES(udev->data_area_mb) / val;
2437
2438 unlock:
2439 mutex_unlock(&udev->cmdr_lock);
2440 return ret;
2441 }
2442
tcmu_set_configfs_dev_params(struct se_device * dev,const char * page,ssize_t count)2443 static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
2444 const char *page, ssize_t count)
2445 {
2446 struct tcmu_dev *udev = TCMU_DEV(dev);
2447 char *orig, *ptr, *opts;
2448 substring_t args[MAX_OPT_ARGS];
2449 int ret = 0, token;
2450
2451 opts = kstrdup(page, GFP_KERNEL);
2452 if (!opts)
2453 return -ENOMEM;
2454
2455 orig = opts;
2456
2457 while ((ptr = strsep(&opts, ",\n")) != NULL) {
2458 if (!*ptr)
2459 continue;
2460
2461 token = match_token(ptr, tokens, args);
2462 switch (token) {
2463 case Opt_dev_config:
2464 if (match_strlcpy(udev->dev_config, &args[0],
2465 TCMU_CONFIG_LEN) == 0) {
2466 ret = -EINVAL;
2467 break;
2468 }
2469 pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
2470 break;
2471 case Opt_dev_size:
2472 ret = match_u64(&args[0], &udev->dev_size);
2473 if (ret < 0)
2474 pr_err("match_u64() failed for dev_size=. Error %d.\n",
2475 ret);
2476 break;
2477 case Opt_hw_block_size:
2478 ret = tcmu_set_dev_attrib(&args[0],
2479 &(dev->dev_attrib.hw_block_size));
2480 break;
2481 case Opt_hw_max_sectors:
2482 ret = tcmu_set_dev_attrib(&args[0],
2483 &(dev->dev_attrib.hw_max_sectors));
2484 break;
2485 case Opt_nl_reply_supported:
2486 ret = match_int(&args[0], &udev->nl_reply_supported);
2487 if (ret < 0)
2488 pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
2489 ret);
2490 break;
2491 case Opt_max_data_area_mb:
2492 ret = tcmu_set_max_blocks_param(udev, &args[0]);
2493 break;
2494 case Opt_data_pages_per_blk:
2495 ret = tcmu_set_data_pages_per_blk(udev, &args[0]);
2496 break;
2497 default:
2498 break;
2499 }
2500
2501 if (ret)
2502 break;
2503 }
2504
2505 kfree(orig);
2506 return (!ret) ? count : ret;
2507 }
2508
tcmu_show_configfs_dev_params(struct se_device * dev,char * b)2509 static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
2510 {
2511 struct tcmu_dev *udev = TCMU_DEV(dev);
2512 ssize_t bl = 0;
2513
2514 bl = sprintf(b + bl, "Config: %s ",
2515 udev->dev_config[0] ? udev->dev_config : "NULL");
2516 bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
2517 bl += sprintf(b + bl, "MaxDataAreaMB: %u ", udev->data_area_mb);
2518 bl += sprintf(b + bl, "DataPagesPerBlk: %u\n", udev->data_pages_per_blk);
2519
2520 return bl;
2521 }
2522
tcmu_get_blocks(struct se_device * dev)2523 static sector_t tcmu_get_blocks(struct se_device *dev)
2524 {
2525 struct tcmu_dev *udev = TCMU_DEV(dev);
2526
2527 return div_u64(udev->dev_size - dev->dev_attrib.block_size,
2528 dev->dev_attrib.block_size);
2529 }
2530
2531 static sense_reason_t
tcmu_parse_cdb(struct se_cmd * cmd)2532 tcmu_parse_cdb(struct se_cmd *cmd)
2533 {
2534 return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
2535 }
2536
tcmu_cmd_time_out_show(struct config_item * item,char * page)2537 static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
2538 {
2539 struct se_dev_attrib *da = container_of(to_config_group(item),
2540 struct se_dev_attrib, da_group);
2541 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2542
2543 return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
2544 }
2545
tcmu_cmd_time_out_store(struct config_item * item,const char * page,size_t count)2546 static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
2547 size_t count)
2548 {
2549 struct se_dev_attrib *da = container_of(to_config_group(item),
2550 struct se_dev_attrib, da_group);
2551 struct tcmu_dev *udev = container_of(da->da_dev,
2552 struct tcmu_dev, se_dev);
2553 u32 val;
2554 int ret;
2555
2556 if (da->da_dev->export_count) {
2557 pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
2558 return -EINVAL;
2559 }
2560
2561 ret = kstrtou32(page, 0, &val);
2562 if (ret < 0)
2563 return ret;
2564
2565 udev->cmd_time_out = val * MSEC_PER_SEC;
2566 return count;
2567 }
2568 CONFIGFS_ATTR(tcmu_, cmd_time_out);
2569
tcmu_qfull_time_out_show(struct config_item * item,char * page)2570 static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
2571 {
2572 struct se_dev_attrib *da = container_of(to_config_group(item),
2573 struct se_dev_attrib, da_group);
2574 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2575
2576 return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
2577 udev->qfull_time_out :
2578 udev->qfull_time_out / MSEC_PER_SEC);
2579 }
2580
tcmu_qfull_time_out_store(struct config_item * item,const char * page,size_t count)2581 static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
2582 const char *page, size_t count)
2583 {
2584 struct se_dev_attrib *da = container_of(to_config_group(item),
2585 struct se_dev_attrib, da_group);
2586 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2587 s32 val;
2588 int ret;
2589
2590 ret = kstrtos32(page, 0, &val);
2591 if (ret < 0)
2592 return ret;
2593
2594 if (val >= 0) {
2595 udev->qfull_time_out = val * MSEC_PER_SEC;
2596 } else if (val == -1) {
2597 udev->qfull_time_out = val;
2598 } else {
2599 printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
2600 return -EINVAL;
2601 }
2602 return count;
2603 }
2604 CONFIGFS_ATTR(tcmu_, qfull_time_out);
2605
tcmu_max_data_area_mb_show(struct config_item * item,char * page)2606 static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
2607 {
2608 struct se_dev_attrib *da = container_of(to_config_group(item),
2609 struct se_dev_attrib, da_group);
2610 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2611
2612 return snprintf(page, PAGE_SIZE, "%u\n", udev->data_area_mb);
2613 }
2614 CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
2615
tcmu_data_pages_per_blk_show(struct config_item * item,char * page)2616 static ssize_t tcmu_data_pages_per_blk_show(struct config_item *item,
2617 char *page)
2618 {
2619 struct se_dev_attrib *da = container_of(to_config_group(item),
2620 struct se_dev_attrib, da_group);
2621 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2622
2623 return snprintf(page, PAGE_SIZE, "%u\n", udev->data_pages_per_blk);
2624 }
2625 CONFIGFS_ATTR_RO(tcmu_, data_pages_per_blk);
2626
tcmu_dev_config_show(struct config_item * item,char * page)2627 static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
2628 {
2629 struct se_dev_attrib *da = container_of(to_config_group(item),
2630 struct se_dev_attrib, da_group);
2631 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2632
2633 return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
2634 }
2635
tcmu_send_dev_config_event(struct tcmu_dev * udev,const char * reconfig_data)2636 static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
2637 const char *reconfig_data)
2638 {
2639 struct sk_buff *skb = NULL;
2640 void *msg_header = NULL;
2641 int ret = 0;
2642
2643 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2644 &skb, &msg_header);
2645 if (ret < 0)
2646 return ret;
2647 ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
2648 if (ret < 0) {
2649 nlmsg_free(skb);
2650 return ret;
2651 }
2652 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2653 skb, msg_header);
2654 }
2655
2656
tcmu_dev_config_store(struct config_item * item,const char * page,size_t count)2657 static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
2658 size_t count)
2659 {
2660 struct se_dev_attrib *da = container_of(to_config_group(item),
2661 struct se_dev_attrib, da_group);
2662 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2663 int ret, len;
2664
2665 len = strlen(page);
2666 if (!len || len > TCMU_CONFIG_LEN - 1)
2667 return -EINVAL;
2668
2669 /* Check if device has been configured before */
2670 if (target_dev_configured(&udev->se_dev)) {
2671 ret = tcmu_send_dev_config_event(udev, page);
2672 if (ret) {
2673 pr_err("Unable to reconfigure device\n");
2674 return ret;
2675 }
2676 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2677
2678 ret = tcmu_update_uio_info(udev);
2679 if (ret)
2680 return ret;
2681 return count;
2682 }
2683 strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
2684
2685 return count;
2686 }
2687 CONFIGFS_ATTR(tcmu_, dev_config);
2688
tcmu_dev_size_show(struct config_item * item,char * page)2689 static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
2690 {
2691 struct se_dev_attrib *da = container_of(to_config_group(item),
2692 struct se_dev_attrib, da_group);
2693 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2694
2695 return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
2696 }
2697
tcmu_send_dev_size_event(struct tcmu_dev * udev,u64 size)2698 static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
2699 {
2700 struct sk_buff *skb = NULL;
2701 void *msg_header = NULL;
2702 int ret = 0;
2703
2704 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2705 &skb, &msg_header);
2706 if (ret < 0)
2707 return ret;
2708 ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
2709 size, TCMU_ATTR_PAD);
2710 if (ret < 0) {
2711 nlmsg_free(skb);
2712 return ret;
2713 }
2714 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2715 skb, msg_header);
2716 }
2717
tcmu_dev_size_store(struct config_item * item,const char * page,size_t count)2718 static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
2719 size_t count)
2720 {
2721 struct se_dev_attrib *da = container_of(to_config_group(item),
2722 struct se_dev_attrib, da_group);
2723 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2724 u64 val;
2725 int ret;
2726
2727 ret = kstrtou64(page, 0, &val);
2728 if (ret < 0)
2729 return ret;
2730
2731 /* Check if device has been configured before */
2732 if (target_dev_configured(&udev->se_dev)) {
2733 ret = tcmu_send_dev_size_event(udev, val);
2734 if (ret) {
2735 pr_err("Unable to reconfigure device\n");
2736 return ret;
2737 }
2738 }
2739 udev->dev_size = val;
2740 return count;
2741 }
2742 CONFIGFS_ATTR(tcmu_, dev_size);
2743
tcmu_nl_reply_supported_show(struct config_item * item,char * page)2744 static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
2745 char *page)
2746 {
2747 struct se_dev_attrib *da = container_of(to_config_group(item),
2748 struct se_dev_attrib, da_group);
2749 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2750
2751 return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
2752 }
2753
tcmu_nl_reply_supported_store(struct config_item * item,const char * page,size_t count)2754 static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
2755 const char *page, size_t count)
2756 {
2757 struct se_dev_attrib *da = container_of(to_config_group(item),
2758 struct se_dev_attrib, da_group);
2759 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2760 s8 val;
2761 int ret;
2762
2763 ret = kstrtos8(page, 0, &val);
2764 if (ret < 0)
2765 return ret;
2766
2767 udev->nl_reply_supported = val;
2768 return count;
2769 }
2770 CONFIGFS_ATTR(tcmu_, nl_reply_supported);
2771
tcmu_emulate_write_cache_show(struct config_item * item,char * page)2772 static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
2773 char *page)
2774 {
2775 struct se_dev_attrib *da = container_of(to_config_group(item),
2776 struct se_dev_attrib, da_group);
2777
2778 return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
2779 }
2780
tcmu_send_emulate_write_cache(struct tcmu_dev * udev,u8 val)2781 static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
2782 {
2783 struct sk_buff *skb = NULL;
2784 void *msg_header = NULL;
2785 int ret = 0;
2786
2787 ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
2788 &skb, &msg_header);
2789 if (ret < 0)
2790 return ret;
2791 ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
2792 if (ret < 0) {
2793 nlmsg_free(skb);
2794 return ret;
2795 }
2796 return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
2797 skb, msg_header);
2798 }
2799
tcmu_emulate_write_cache_store(struct config_item * item,const char * page,size_t count)2800 static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
2801 const char *page, size_t count)
2802 {
2803 struct se_dev_attrib *da = container_of(to_config_group(item),
2804 struct se_dev_attrib, da_group);
2805 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2806 u8 val;
2807 int ret;
2808
2809 ret = kstrtou8(page, 0, &val);
2810 if (ret < 0)
2811 return ret;
2812
2813 /* Check if device has been configured before */
2814 if (target_dev_configured(&udev->se_dev)) {
2815 ret = tcmu_send_emulate_write_cache(udev, val);
2816 if (ret) {
2817 pr_err("Unable to reconfigure device\n");
2818 return ret;
2819 }
2820 }
2821
2822 da->emulate_write_cache = val;
2823 return count;
2824 }
2825 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
2826
tcmu_tmr_notification_show(struct config_item * item,char * page)2827 static ssize_t tcmu_tmr_notification_show(struct config_item *item, char *page)
2828 {
2829 struct se_dev_attrib *da = container_of(to_config_group(item),
2830 struct se_dev_attrib, da_group);
2831 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2832
2833 return snprintf(page, PAGE_SIZE, "%i\n",
2834 test_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags));
2835 }
2836
tcmu_tmr_notification_store(struct config_item * item,const char * page,size_t count)2837 static ssize_t tcmu_tmr_notification_store(struct config_item *item,
2838 const char *page, size_t count)
2839 {
2840 struct se_dev_attrib *da = container_of(to_config_group(item),
2841 struct se_dev_attrib, da_group);
2842 struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
2843 u8 val;
2844 int ret;
2845
2846 ret = kstrtou8(page, 0, &val);
2847 if (ret < 0)
2848 return ret;
2849 if (val > 1)
2850 return -EINVAL;
2851
2852 if (val)
2853 set_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2854 else
2855 clear_bit(TCMU_DEV_BIT_TMR_NOTIFY, &udev->flags);
2856 return count;
2857 }
2858 CONFIGFS_ATTR(tcmu_, tmr_notification);
2859
tcmu_block_dev_show(struct config_item * item,char * page)2860 static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
2861 {
2862 struct se_device *se_dev = container_of(to_config_group(item),
2863 struct se_device,
2864 dev_action_group);
2865 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2866
2867 if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
2868 return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
2869 else
2870 return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
2871 }
2872
tcmu_block_dev_store(struct config_item * item,const char * page,size_t count)2873 static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
2874 size_t count)
2875 {
2876 struct se_device *se_dev = container_of(to_config_group(item),
2877 struct se_device,
2878 dev_action_group);
2879 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2880 u8 val;
2881 int ret;
2882
2883 if (!target_dev_configured(&udev->se_dev)) {
2884 pr_err("Device is not configured.\n");
2885 return -EINVAL;
2886 }
2887
2888 ret = kstrtou8(page, 0, &val);
2889 if (ret < 0)
2890 return ret;
2891
2892 if (val > 1) {
2893 pr_err("Invalid block value %d\n", val);
2894 return -EINVAL;
2895 }
2896
2897 if (!val)
2898 tcmu_unblock_dev(udev);
2899 else
2900 tcmu_block_dev(udev);
2901 return count;
2902 }
2903 CONFIGFS_ATTR(tcmu_, block_dev);
2904
tcmu_reset_ring_store(struct config_item * item,const char * page,size_t count)2905 static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
2906 size_t count)
2907 {
2908 struct se_device *se_dev = container_of(to_config_group(item),
2909 struct se_device,
2910 dev_action_group);
2911 struct tcmu_dev *udev = TCMU_DEV(se_dev);
2912 u8 val;
2913 int ret;
2914
2915 if (!target_dev_configured(&udev->se_dev)) {
2916 pr_err("Device is not configured.\n");
2917 return -EINVAL;
2918 }
2919
2920 ret = kstrtou8(page, 0, &val);
2921 if (ret < 0)
2922 return ret;
2923
2924 if (val != 1 && val != 2) {
2925 pr_err("Invalid reset ring value %d\n", val);
2926 return -EINVAL;
2927 }
2928
2929 tcmu_reset_ring(udev, val);
2930 return count;
2931 }
2932 CONFIGFS_ATTR_WO(tcmu_, reset_ring);
2933
2934 static struct configfs_attribute *tcmu_attrib_attrs[] = {
2935 &tcmu_attr_cmd_time_out,
2936 &tcmu_attr_qfull_time_out,
2937 &tcmu_attr_max_data_area_mb,
2938 &tcmu_attr_data_pages_per_blk,
2939 &tcmu_attr_dev_config,
2940 &tcmu_attr_dev_size,
2941 &tcmu_attr_emulate_write_cache,
2942 &tcmu_attr_tmr_notification,
2943 &tcmu_attr_nl_reply_supported,
2944 NULL,
2945 };
2946
2947 static struct configfs_attribute **tcmu_attrs;
2948
2949 static struct configfs_attribute *tcmu_action_attrs[] = {
2950 &tcmu_attr_block_dev,
2951 &tcmu_attr_reset_ring,
2952 NULL,
2953 };
2954
2955 static struct target_backend_ops tcmu_ops = {
2956 .name = "user",
2957 .owner = THIS_MODULE,
2958 .transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH,
2959 .transport_flags_changeable = TRANSPORT_FLAG_PASSTHROUGH_PGR |
2960 TRANSPORT_FLAG_PASSTHROUGH_ALUA,
2961 .attach_hba = tcmu_attach_hba,
2962 .detach_hba = tcmu_detach_hba,
2963 .alloc_device = tcmu_alloc_device,
2964 .configure_device = tcmu_configure_device,
2965 .destroy_device = tcmu_destroy_device,
2966 .free_device = tcmu_free_device,
2967 .unplug_device = tcmu_unplug_device,
2968 .plug_device = tcmu_plug_device,
2969 .parse_cdb = tcmu_parse_cdb,
2970 .tmr_notify = tcmu_tmr_notify,
2971 .set_configfs_dev_params = tcmu_set_configfs_dev_params,
2972 .show_configfs_dev_params = tcmu_show_configfs_dev_params,
2973 .get_device_type = sbc_get_device_type,
2974 .get_blocks = tcmu_get_blocks,
2975 .tb_dev_action_attrs = tcmu_action_attrs,
2976 };
2977
find_free_blocks(void)2978 static void find_free_blocks(void)
2979 {
2980 struct tcmu_dev *udev;
2981 loff_t off;
2982 u32 pages_freed, total_pages_freed = 0;
2983 u32 start, end, block, total_blocks_freed = 0;
2984
2985 if (atomic_read(&global_page_count) <= tcmu_global_max_pages)
2986 return;
2987
2988 mutex_lock(&root_udev_mutex);
2989 list_for_each_entry(udev, &root_udev, node) {
2990 mutex_lock(&udev->cmdr_lock);
2991
2992 if (!target_dev_configured(&udev->se_dev)) {
2993 mutex_unlock(&udev->cmdr_lock);
2994 continue;
2995 }
2996
2997 /* Try to complete the finished commands first */
2998 if (tcmu_handle_completions(udev))
2999 run_qfull_queue(udev, false);
3000
3001 /* Skip the udevs in idle */
3002 if (!udev->dbi_thresh) {
3003 mutex_unlock(&udev->cmdr_lock);
3004 continue;
3005 }
3006
3007 end = udev->dbi_max + 1;
3008 block = find_last_bit(udev->data_bitmap, end);
3009 if (block == udev->dbi_max) {
3010 /*
3011 * The last bit is dbi_max, so it is not possible
3012 * reclaim any blocks.
3013 */
3014 mutex_unlock(&udev->cmdr_lock);
3015 continue;
3016 } else if (block == end) {
3017 /* The current udev will goto idle state */
3018 udev->dbi_thresh = start = 0;
3019 udev->dbi_max = 0;
3020 } else {
3021 udev->dbi_thresh = start = block + 1;
3022 udev->dbi_max = block;
3023 }
3024
3025 /* Here will truncate the data area from off */
3026 off = udev->data_off + (loff_t)start * udev->data_blk_size;
3027 unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
3028
3029 /* Release the block pages */
3030 pages_freed = tcmu_blocks_release(udev, start, end - 1);
3031 mutex_unlock(&udev->cmdr_lock);
3032
3033 total_pages_freed += pages_freed;
3034 total_blocks_freed += end - start;
3035 pr_debug("Freed %u pages (total %u) from %u blocks (total %u) from %s.\n",
3036 pages_freed, total_pages_freed, end - start,
3037 total_blocks_freed, udev->name);
3038 }
3039 mutex_unlock(&root_udev_mutex);
3040
3041 if (atomic_read(&global_page_count) > tcmu_global_max_pages)
3042 schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
3043 }
3044
check_timedout_devices(void)3045 static void check_timedout_devices(void)
3046 {
3047 struct tcmu_dev *udev, *tmp_dev;
3048 struct tcmu_cmd *cmd, *tmp_cmd;
3049 LIST_HEAD(devs);
3050
3051 spin_lock_bh(&timed_out_udevs_lock);
3052 list_splice_init(&timed_out_udevs, &devs);
3053
3054 list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
3055 list_del_init(&udev->timedout_entry);
3056 spin_unlock_bh(&timed_out_udevs_lock);
3057
3058 mutex_lock(&udev->cmdr_lock);
3059
3060 /*
3061 * If cmd_time_out is disabled but qfull is set deadline
3062 * will only reflect the qfull timeout. Ignore it.
3063 */
3064 if (udev->cmd_time_out) {
3065 list_for_each_entry_safe(cmd, tmp_cmd,
3066 &udev->inflight_queue,
3067 queue_entry) {
3068 tcmu_check_expired_ring_cmd(cmd);
3069 }
3070 tcmu_set_next_deadline(&udev->inflight_queue,
3071 &udev->cmd_timer);
3072 }
3073 list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue,
3074 queue_entry) {
3075 tcmu_check_expired_queue_cmd(cmd);
3076 }
3077 tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
3078
3079 mutex_unlock(&udev->cmdr_lock);
3080
3081 spin_lock_bh(&timed_out_udevs_lock);
3082 }
3083
3084 spin_unlock_bh(&timed_out_udevs_lock);
3085 }
3086
tcmu_unmap_work_fn(struct work_struct * work)3087 static void tcmu_unmap_work_fn(struct work_struct *work)
3088 {
3089 check_timedout_devices();
3090 find_free_blocks();
3091 }
3092
tcmu_module_init(void)3093 static int __init tcmu_module_init(void)
3094 {
3095 int ret, i, k, len = 0;
3096
3097 BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
3098
3099 INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
3100
3101 tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
3102 sizeof(struct tcmu_cmd),
3103 __alignof__(struct tcmu_cmd),
3104 0, NULL);
3105 if (!tcmu_cmd_cache)
3106 return -ENOMEM;
3107
3108 tcmu_root_device = root_device_register("tcm_user");
3109 if (IS_ERR(tcmu_root_device)) {
3110 ret = PTR_ERR(tcmu_root_device);
3111 goto out_free_cache;
3112 }
3113
3114 ret = genl_register_family(&tcmu_genl_family);
3115 if (ret < 0) {
3116 goto out_unreg_device;
3117 }
3118
3119 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3120 len += sizeof(struct configfs_attribute *);
3121 for (i = 0; passthrough_pr_attrib_attrs[i] != NULL; i++)
3122 len += sizeof(struct configfs_attribute *);
3123 for (i = 0; tcmu_attrib_attrs[i] != NULL; i++)
3124 len += sizeof(struct configfs_attribute *);
3125 len += sizeof(struct configfs_attribute *);
3126
3127 tcmu_attrs = kzalloc(len, GFP_KERNEL);
3128 if (!tcmu_attrs) {
3129 ret = -ENOMEM;
3130 goto out_unreg_genl;
3131 }
3132
3133 for (i = 0; passthrough_attrib_attrs[i] != NULL; i++)
3134 tcmu_attrs[i] = passthrough_attrib_attrs[i];
3135 for (k = 0; passthrough_pr_attrib_attrs[k] != NULL; k++)
3136 tcmu_attrs[i++] = passthrough_pr_attrib_attrs[k];
3137 for (k = 0; tcmu_attrib_attrs[k] != NULL; k++)
3138 tcmu_attrs[i++] = tcmu_attrib_attrs[k];
3139 tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
3140
3141 ret = transport_backend_register(&tcmu_ops);
3142 if (ret)
3143 goto out_attrs;
3144
3145 return 0;
3146
3147 out_attrs:
3148 kfree(tcmu_attrs);
3149 out_unreg_genl:
3150 genl_unregister_family(&tcmu_genl_family);
3151 out_unreg_device:
3152 root_device_unregister(tcmu_root_device);
3153 out_free_cache:
3154 kmem_cache_destroy(tcmu_cmd_cache);
3155
3156 return ret;
3157 }
3158
tcmu_module_exit(void)3159 static void __exit tcmu_module_exit(void)
3160 {
3161 cancel_delayed_work_sync(&tcmu_unmap_work);
3162 target_backend_unregister(&tcmu_ops);
3163 kfree(tcmu_attrs);
3164 genl_unregister_family(&tcmu_genl_family);
3165 root_device_unregister(tcmu_root_device);
3166 kmem_cache_destroy(tcmu_cmd_cache);
3167 }
3168
3169 MODULE_DESCRIPTION("TCM USER subsystem plugin");
3170 MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
3171 MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
3172 MODULE_LICENSE("GPL");
3173
3174 module_init(tcmu_module_init);
3175 module_exit(tcmu_module_exit);
3176