nvme: only add a controller to dev_list after it's been fully initialized
[linux-2.6-block.git] / drivers / nvme / host / pci.c
1 /*
2  * NVM Express device driver
3  * Copyright (c) 2011-2014, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  */
14
15 #include <linux/bitops.h>
16 #include <linux/blkdev.h>
17 #include <linux/blk-mq.h>
18 #include <linux/cpu.h>
19 #include <linux/delay.h>
20 #include <linux/errno.h>
21 #include <linux/fs.h>
22 #include <linux/genhd.h>
23 #include <linux/hdreg.h>
24 #include <linux/idr.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/io.h>
28 #include <linux/kdev_t.h>
29 #include <linux/kthread.h>
30 #include <linux/kernel.h>
31 #include <linux/mm.h>
32 #include <linux/module.h>
33 #include <linux/moduleparam.h>
34 #include <linux/pci.h>
35 #include <linux/poison.h>
36 #include <linux/ptrace.h>
37 #include <linux/sched.h>
38 #include <linux/slab.h>
39 #include <linux/t10-pi.h>
40 #include <linux/types.h>
41 #include <linux/io-64-nonatomic-lo-hi.h>
42 #include <asm/unaligned.h>
43
44 #include "nvme.h"
45
46 #define NVME_Q_DEPTH            1024
47 #define NVME_AQ_DEPTH           256
48 #define SQ_SIZE(depth)          (depth * sizeof(struct nvme_command))
49 #define CQ_SIZE(depth)          (depth * sizeof(struct nvme_completion))
50
51 unsigned char admin_timeout = 60;
52 module_param(admin_timeout, byte, 0644);
53 MODULE_PARM_DESC(admin_timeout, "timeout in seconds for admin commands");
54
55 unsigned char nvme_io_timeout = 30;
56 module_param_named(io_timeout, nvme_io_timeout, byte, 0644);
57 MODULE_PARM_DESC(io_timeout, "timeout in seconds for I/O");
58
59 unsigned char shutdown_timeout = 5;
60 module_param(shutdown_timeout, byte, 0644);
61 MODULE_PARM_DESC(shutdown_timeout, "timeout in seconds for controller shutdown");
62
63 static int use_threaded_interrupts;
64 module_param(use_threaded_interrupts, int, 0);
65
66 static bool use_cmb_sqes = true;
67 module_param(use_cmb_sqes, bool, 0644);
68 MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes");
69
70 static LIST_HEAD(dev_list);
71 static struct task_struct *nvme_thread;
72 static struct workqueue_struct *nvme_workq;
73 static wait_queue_head_t nvme_kthread_wait;
74
75 struct nvme_dev;
76 struct nvme_queue;
77 struct nvme_iod;
78
79 static int __nvme_reset(struct nvme_dev *dev);
80 static int nvme_reset(struct nvme_dev *dev);
81 static void nvme_process_cq(struct nvme_queue *nvmeq);
82 static void nvme_unmap_data(struct nvme_dev *dev, struct nvme_iod *iod);
83 static void nvme_dead_ctrl(struct nvme_dev *dev);
84
85 struct async_cmd_info {
86         struct kthread_work work;
87         struct kthread_worker *worker;
88         struct request *req;
89         u32 result;
90         int status;
91         void *ctx;
92 };
93
94 /*
95  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
96  */
97 struct nvme_dev {
98         struct list_head node;
99         struct nvme_queue **queues;
100         struct blk_mq_tag_set tagset;
101         struct blk_mq_tag_set admin_tagset;
102         u32 __iomem *dbs;
103         struct device *dev;
104         struct dma_pool *prp_page_pool;
105         struct dma_pool *prp_small_pool;
106         unsigned queue_count;
107         unsigned online_queues;
108         unsigned max_qid;
109         int q_depth;
110         u32 db_stride;
111         struct msix_entry *entry;
112         void __iomem *bar;
113         struct work_struct reset_work;
114         struct work_struct probe_work;
115         struct work_struct scan_work;
116         bool subsystem;
117         void __iomem *cmb;
118         dma_addr_t cmb_dma_addr;
119         u64 cmb_size;
120         u32 cmbsz;
121
122         struct nvme_ctrl ctrl;
123 };
124
125 static inline struct nvme_dev *to_nvme_dev(struct nvme_ctrl *ctrl)
126 {
127         return container_of(ctrl, struct nvme_dev, ctrl);
128 }
129
130 /*
131  * An NVM Express queue.  Each device has at least two (one for admin
132  * commands and one for I/O commands).
133  */
134 struct nvme_queue {
135         struct device *q_dmadev;
136         struct nvme_dev *dev;
137         char irqname[24];       /* nvme4294967295-65535\0 */
138         spinlock_t q_lock;
139         struct nvme_command *sq_cmds;
140         struct nvme_command __iomem *sq_cmds_io;
141         volatile struct nvme_completion *cqes;
142         struct blk_mq_tags **tags;
143         dma_addr_t sq_dma_addr;
144         dma_addr_t cq_dma_addr;
145         u32 __iomem *q_db;
146         u16 q_depth;
147         s16 cq_vector;
148         u16 sq_head;
149         u16 sq_tail;
150         u16 cq_head;
151         u16 qid;
152         u8 cq_phase;
153         u8 cqe_seen;
154         struct async_cmd_info cmdinfo;
155 };
156
157 /*
158  * The nvme_iod describes the data in an I/O, including the list of PRP
159  * entries.  You can't see it in this data structure because C doesn't let
160  * me express that.  Use nvme_alloc_iod to ensure there's enough space
161  * allocated to store the PRP list.
162  */
163 struct nvme_iod {
164         unsigned long private;  /* For the use of the submitter of the I/O */
165         int npages;             /* In the PRP list. 0 means small pool in use */
166         int offset;             /* Of PRP list */
167         int nents;              /* Used in scatterlist */
168         int length;             /* Of data, in bytes */
169         dma_addr_t first_dma;
170         struct scatterlist meta_sg[1]; /* metadata requires single contiguous buffer */
171         struct scatterlist sg[0];
172 };
173
174 /*
175  * Check we didin't inadvertently grow the command struct
176  */
177 static inline void _nvme_check_size(void)
178 {
179         BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
180         BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
181         BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
182         BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
183         BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
184         BUILD_BUG_ON(sizeof(struct nvme_format_cmd) != 64);
185         BUILD_BUG_ON(sizeof(struct nvme_abort_cmd) != 64);
186         BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
187         BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != 4096);
188         BUILD_BUG_ON(sizeof(struct nvme_id_ns) != 4096);
189         BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
190         BUILD_BUG_ON(sizeof(struct nvme_smart_log) != 512);
191 }
192
193 typedef void (*nvme_completion_fn)(struct nvme_queue *, void *,
194                                                 struct nvme_completion *);
195
196 struct nvme_cmd_info {
197         nvme_completion_fn fn;
198         void *ctx;
199         int aborted;
200         struct nvme_queue *nvmeq;
201         struct nvme_iod iod[0];
202 };
203
204 /*
205  * Max size of iod being embedded in the request payload
206  */
207 #define NVME_INT_PAGES          2
208 #define NVME_INT_BYTES(dev)     (NVME_INT_PAGES * (dev)->ctrl.page_size)
209 #define NVME_INT_MASK           0x01
210
211 /*
212  * Will slightly overestimate the number of pages needed.  This is OK
213  * as it only leads to a small amount of wasted memory for the lifetime of
214  * the I/O.
215  */
216 static int nvme_npages(unsigned size, struct nvme_dev *dev)
217 {
218         unsigned nprps = DIV_ROUND_UP(size + dev->ctrl.page_size,
219                                       dev->ctrl.page_size);
220         return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
221 }
222
223 static unsigned int nvme_cmd_size(struct nvme_dev *dev)
224 {
225         unsigned int ret = sizeof(struct nvme_cmd_info);
226
227         ret += sizeof(struct nvme_iod);
228         ret += sizeof(__le64 *) * nvme_npages(NVME_INT_BYTES(dev), dev);
229         ret += sizeof(struct scatterlist) * NVME_INT_PAGES;
230
231         return ret;
232 }
233
234 static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
235                                 unsigned int hctx_idx)
236 {
237         struct nvme_dev *dev = data;
238         struct nvme_queue *nvmeq = dev->queues[0];
239
240         WARN_ON(hctx_idx != 0);
241         WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);
242         WARN_ON(nvmeq->tags);
243
244         hctx->driver_data = nvmeq;
245         nvmeq->tags = &dev->admin_tagset.tags[0];
246         return 0;
247 }
248
249 static void nvme_admin_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
250 {
251         struct nvme_queue *nvmeq = hctx->driver_data;
252
253         nvmeq->tags = NULL;
254 }
255
256 static int nvme_admin_init_request(void *data, struct request *req,
257                                 unsigned int hctx_idx, unsigned int rq_idx,
258                                 unsigned int numa_node)
259 {
260         struct nvme_dev *dev = data;
261         struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
262         struct nvme_queue *nvmeq = dev->queues[0];
263
264         BUG_ON(!nvmeq);
265         cmd->nvmeq = nvmeq;
266         return 0;
267 }
268
269 static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
270                           unsigned int hctx_idx)
271 {
272         struct nvme_dev *dev = data;
273         struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
274
275         if (!nvmeq->tags)
276                 nvmeq->tags = &dev->tagset.tags[hctx_idx];
277
278         WARN_ON(dev->tagset.tags[hctx_idx] != hctx->tags);
279         hctx->driver_data = nvmeq;
280         return 0;
281 }
282
283 static int nvme_init_request(void *data, struct request *req,
284                                 unsigned int hctx_idx, unsigned int rq_idx,
285                                 unsigned int numa_node)
286 {
287         struct nvme_dev *dev = data;
288         struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
289         struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
290
291         BUG_ON(!nvmeq);
292         cmd->nvmeq = nvmeq;
293         return 0;
294 }
295
296 static void nvme_set_info(struct nvme_cmd_info *cmd, void *ctx,
297                                 nvme_completion_fn handler)
298 {
299         cmd->fn = handler;
300         cmd->ctx = ctx;
301         cmd->aborted = 0;
302         blk_mq_start_request(blk_mq_rq_from_pdu(cmd));
303 }
304
305 static void *iod_get_private(struct nvme_iod *iod)
306 {
307         return (void *) (iod->private & ~0x1UL);
308 }
309
310 /*
311  * If bit 0 is set, the iod is embedded in the request payload.
312  */
313 static bool iod_should_kfree(struct nvme_iod *iod)
314 {
315         return (iod->private & NVME_INT_MASK) == 0;
316 }
317
318 /* Special values must be less than 0x1000 */
319 #define CMD_CTX_BASE            ((void *)POISON_POINTER_DELTA)
320 #define CMD_CTX_CANCELLED       (0x30C + CMD_CTX_BASE)
321 #define CMD_CTX_COMPLETED       (0x310 + CMD_CTX_BASE)
322 #define CMD_CTX_INVALID         (0x314 + CMD_CTX_BASE)
323
324 static void special_completion(struct nvme_queue *nvmeq, void *ctx,
325                                                 struct nvme_completion *cqe)
326 {
327         if (ctx == CMD_CTX_CANCELLED)
328                 return;
329         if (ctx == CMD_CTX_COMPLETED) {
330                 dev_warn(nvmeq->q_dmadev,
331                                 "completed id %d twice on queue %d\n",
332                                 cqe->command_id, le16_to_cpup(&cqe->sq_id));
333                 return;
334         }
335         if (ctx == CMD_CTX_INVALID) {
336                 dev_warn(nvmeq->q_dmadev,
337                                 "invalid id %d completed on queue %d\n",
338                                 cqe->command_id, le16_to_cpup(&cqe->sq_id));
339                 return;
340         }
341         dev_warn(nvmeq->q_dmadev, "Unknown special completion %p\n", ctx);
342 }
343
344 static void *cancel_cmd_info(struct nvme_cmd_info *cmd, nvme_completion_fn *fn)
345 {
346         void *ctx;
347
348         if (fn)
349                 *fn = cmd->fn;
350         ctx = cmd->ctx;
351         cmd->fn = special_completion;
352         cmd->ctx = CMD_CTX_CANCELLED;
353         return ctx;
354 }
355
356 static void async_req_completion(struct nvme_queue *nvmeq, void *ctx,
357                                                 struct nvme_completion *cqe)
358 {
359         u32 result = le32_to_cpup(&cqe->result);
360         u16 status = le16_to_cpup(&cqe->status) >> 1;
361
362         if (status == NVME_SC_SUCCESS || status == NVME_SC_ABORT_REQ)
363                 ++nvmeq->dev->ctrl.event_limit;
364         if (status != NVME_SC_SUCCESS)
365                 return;
366
367         switch (result & 0xff07) {
368         case NVME_AER_NOTICE_NS_CHANGED:
369                 dev_info(nvmeq->q_dmadev, "rescanning\n");
370                 schedule_work(&nvmeq->dev->scan_work);
371         default:
372                 dev_warn(nvmeq->q_dmadev, "async event result %08x\n", result);
373         }
374 }
375
376 static void abort_completion(struct nvme_queue *nvmeq, void *ctx,
377                                                 struct nvme_completion *cqe)
378 {
379         struct request *req = ctx;
380
381         u16 status = le16_to_cpup(&cqe->status) >> 1;
382         u32 result = le32_to_cpup(&cqe->result);
383
384         blk_mq_free_request(req);
385
386         dev_warn(nvmeq->q_dmadev, "Abort status:%x result:%x", status, result);
387         ++nvmeq->dev->ctrl.abort_limit;
388 }
389
390 static void async_completion(struct nvme_queue *nvmeq, void *ctx,
391                                                 struct nvme_completion *cqe)
392 {
393         struct async_cmd_info *cmdinfo = ctx;
394         cmdinfo->result = le32_to_cpup(&cqe->result);
395         cmdinfo->status = le16_to_cpup(&cqe->status) >> 1;
396         queue_kthread_work(cmdinfo->worker, &cmdinfo->work);
397         blk_mq_free_request(cmdinfo->req);
398 }
399
400 static inline struct nvme_cmd_info *get_cmd_from_tag(struct nvme_queue *nvmeq,
401                                   unsigned int tag)
402 {
403         struct request *req = blk_mq_tag_to_rq(*nvmeq->tags, tag);
404
405         return blk_mq_rq_to_pdu(req);
406 }
407
408 /*
409  * Called with local interrupts disabled and the q_lock held.  May not sleep.
410  */
411 static void *nvme_finish_cmd(struct nvme_queue *nvmeq, int tag,
412                                                 nvme_completion_fn *fn)
413 {
414         struct nvme_cmd_info *cmd = get_cmd_from_tag(nvmeq, tag);
415         void *ctx;
416         if (tag >= nvmeq->q_depth) {
417                 *fn = special_completion;
418                 return CMD_CTX_INVALID;
419         }
420         if (fn)
421                 *fn = cmd->fn;
422         ctx = cmd->ctx;
423         cmd->fn = special_completion;
424         cmd->ctx = CMD_CTX_COMPLETED;
425         return ctx;
426 }
427
428 /**
429  * nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
430  * @nvmeq: The queue to use
431  * @cmd: The command to send
432  *
433  * Safe to use from interrupt context
434  */
435 static void __nvme_submit_cmd(struct nvme_queue *nvmeq,
436                                                 struct nvme_command *cmd)
437 {
438         u16 tail = nvmeq->sq_tail;
439
440         if (nvmeq->sq_cmds_io)
441                 memcpy_toio(&nvmeq->sq_cmds_io[tail], cmd, sizeof(*cmd));
442         else
443                 memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
444
445         if (++tail == nvmeq->q_depth)
446                 tail = 0;
447         writel(tail, nvmeq->q_db);
448         nvmeq->sq_tail = tail;
449 }
450
451 static void nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
452 {
453         unsigned long flags;
454         spin_lock_irqsave(&nvmeq->q_lock, flags);
455         __nvme_submit_cmd(nvmeq, cmd);
456         spin_unlock_irqrestore(&nvmeq->q_lock, flags);
457 }
458
459 static __le64 **iod_list(struct nvme_iod *iod)
460 {
461         return ((void *)iod) + iod->offset;
462 }
463
464 static inline void iod_init(struct nvme_iod *iod, unsigned nbytes,
465                             unsigned nseg, unsigned long private)
466 {
467         iod->private = private;
468         iod->offset = offsetof(struct nvme_iod, sg[nseg]);
469         iod->npages = -1;
470         iod->length = nbytes;
471         iod->nents = 0;
472 }
473
474 static struct nvme_iod *
475 __nvme_alloc_iod(unsigned nseg, unsigned bytes, struct nvme_dev *dev,
476                  unsigned long priv, gfp_t gfp)
477 {
478         struct nvme_iod *iod = kmalloc(sizeof(struct nvme_iod) +
479                                 sizeof(__le64 *) * nvme_npages(bytes, dev) +
480                                 sizeof(struct scatterlist) * nseg, gfp);
481
482         if (iod)
483                 iod_init(iod, bytes, nseg, priv);
484
485         return iod;
486 }
487
488 static struct nvme_iod *nvme_alloc_iod(struct request *rq, struct nvme_dev *dev,
489                                        gfp_t gfp)
490 {
491         unsigned size = !(rq->cmd_flags & REQ_DISCARD) ? blk_rq_bytes(rq) :
492                                                 sizeof(struct nvme_dsm_range);
493         struct nvme_iod *iod;
494
495         if (rq->nr_phys_segments <= NVME_INT_PAGES &&
496             size <= NVME_INT_BYTES(dev)) {
497                 struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(rq);
498
499                 iod = cmd->iod;
500                 iod_init(iod, size, rq->nr_phys_segments,
501                                 (unsigned long) rq | NVME_INT_MASK);
502                 return iod;
503         }
504
505         return __nvme_alloc_iod(rq->nr_phys_segments, size, dev,
506                                 (unsigned long) rq, gfp);
507 }
508
509 static void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod)
510 {
511         const int last_prp = dev->ctrl.page_size / 8 - 1;
512         int i;
513         __le64 **list = iod_list(iod);
514         dma_addr_t prp_dma = iod->first_dma;
515
516         if (iod->npages == 0)
517                 dma_pool_free(dev->prp_small_pool, list[0], prp_dma);
518         for (i = 0; i < iod->npages; i++) {
519                 __le64 *prp_list = list[i];
520                 dma_addr_t next_prp_dma = le64_to_cpu(prp_list[last_prp]);
521                 dma_pool_free(dev->prp_page_pool, prp_list, prp_dma);
522                 prp_dma = next_prp_dma;
523         }
524
525         if (iod_should_kfree(iod))
526                 kfree(iod);
527 }
528
529 #ifdef CONFIG_BLK_DEV_INTEGRITY
530 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
531 {
532         if (be32_to_cpu(pi->ref_tag) == v)
533                 pi->ref_tag = cpu_to_be32(p);
534 }
535
536 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
537 {
538         if (be32_to_cpu(pi->ref_tag) == p)
539                 pi->ref_tag = cpu_to_be32(v);
540 }
541
542 /**
543  * nvme_dif_remap - remaps ref tags to bip seed and physical lba
544  *
545  * The virtual start sector is the one that was originally submitted by the
546  * block layer. Due to partitioning, MD/DM cloning, etc. the actual physical
547  * start sector may be different. Remap protection information to match the
548  * physical LBA on writes, and back to the original seed on reads.
549  *
550  * Type 0 and 3 do not have a ref tag, so no remapping required.
551  */
552 static void nvme_dif_remap(struct request *req,
553                         void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
554 {
555         struct nvme_ns *ns = req->rq_disk->private_data;
556         struct bio_integrity_payload *bip;
557         struct t10_pi_tuple *pi;
558         void *p, *pmap;
559         u32 i, nlb, ts, phys, virt;
560
561         if (!ns->pi_type || ns->pi_type == NVME_NS_DPS_PI_TYPE3)
562                 return;
563
564         bip = bio_integrity(req->bio);
565         if (!bip)
566                 return;
567
568         pmap = kmap_atomic(bip->bip_vec->bv_page) + bip->bip_vec->bv_offset;
569
570         p = pmap;
571         virt = bip_get_seed(bip);
572         phys = nvme_block_nr(ns, blk_rq_pos(req));
573         nlb = (blk_rq_bytes(req) >> ns->lba_shift);
574         ts = ns->disk->queue->integrity.tuple_size;
575
576         for (i = 0; i < nlb; i++, virt++, phys++) {
577                 pi = (struct t10_pi_tuple *)p;
578                 dif_swap(phys, virt, pi);
579                 p += ts;
580         }
581         kunmap_atomic(pmap);
582 }
583 #else /* CONFIG_BLK_DEV_INTEGRITY */
584 static void nvme_dif_remap(struct request *req,
585                         void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
586 {
587 }
588 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
589 {
590 }
591 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
592 {
593 }
594 #endif
595
596 static void req_completion(struct nvme_queue *nvmeq, void *ctx,
597                                                 struct nvme_completion *cqe)
598 {
599         struct nvme_iod *iod = ctx;
600         struct request *req = iod_get_private(iod);
601         struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
602         u16 status = le16_to_cpup(&cqe->status) >> 1;
603         int error = 0;
604
605         if (unlikely(status)) {
606                 if (!(status & NVME_SC_DNR || blk_noretry_request(req))
607                     && (jiffies - req->start_time) < req->timeout) {
608                         unsigned long flags;
609
610                         nvme_unmap_data(nvmeq->dev, iod);
611
612                         blk_mq_requeue_request(req);
613                         spin_lock_irqsave(req->q->queue_lock, flags);
614                         if (!blk_queue_stopped(req->q))
615                                 blk_mq_kick_requeue_list(req->q);
616                         spin_unlock_irqrestore(req->q->queue_lock, flags);
617                         return;
618                 }
619
620                 if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
621                         if (cmd_rq->ctx == CMD_CTX_CANCELLED)
622                                 error = -EINTR;
623                         else
624                                 error = status;
625                 } else {
626                         error = nvme_error_status(status);
627                 }
628         }
629
630         if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
631                 u32 result = le32_to_cpup(&cqe->result);
632                 req->special = (void *)(uintptr_t)result;
633         }
634
635         if (cmd_rq->aborted)
636                 dev_warn(nvmeq->dev->dev,
637                         "completing aborted command with status:%04x\n",
638                         error);
639
640         nvme_unmap_data(nvmeq->dev, iod);
641         blk_mq_complete_request(req, error);
642 }
643
644 static bool nvme_setup_prps(struct nvme_dev *dev, struct nvme_iod *iod,
645                 int total_len)
646 {
647         struct dma_pool *pool;
648         int length = total_len;
649         struct scatterlist *sg = iod->sg;
650         int dma_len = sg_dma_len(sg);
651         u64 dma_addr = sg_dma_address(sg);
652         u32 page_size = dev->ctrl.page_size;
653         int offset = dma_addr & (page_size - 1);
654         __le64 *prp_list;
655         __le64 **list = iod_list(iod);
656         dma_addr_t prp_dma;
657         int nprps, i;
658
659         length -= (page_size - offset);
660         if (length <= 0)
661                 return true;
662
663         dma_len -= (page_size - offset);
664         if (dma_len) {
665                 dma_addr += (page_size - offset);
666         } else {
667                 sg = sg_next(sg);
668                 dma_addr = sg_dma_address(sg);
669                 dma_len = sg_dma_len(sg);
670         }
671
672         if (length <= page_size) {
673                 iod->first_dma = dma_addr;
674                 return true;
675         }
676
677         nprps = DIV_ROUND_UP(length, page_size);
678         if (nprps <= (256 / 8)) {
679                 pool = dev->prp_small_pool;
680                 iod->npages = 0;
681         } else {
682                 pool = dev->prp_page_pool;
683                 iod->npages = 1;
684         }
685
686         prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
687         if (!prp_list) {
688                 iod->first_dma = dma_addr;
689                 iod->npages = -1;
690                 return false;
691         }
692         list[0] = prp_list;
693         iod->first_dma = prp_dma;
694         i = 0;
695         for (;;) {
696                 if (i == page_size >> 3) {
697                         __le64 *old_prp_list = prp_list;
698                         prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
699                         if (!prp_list)
700                                 return false;
701                         list[iod->npages++] = prp_list;
702                         prp_list[0] = old_prp_list[i - 1];
703                         old_prp_list[i - 1] = cpu_to_le64(prp_dma);
704                         i = 1;
705                 }
706                 prp_list[i++] = cpu_to_le64(dma_addr);
707                 dma_len -= page_size;
708                 dma_addr += page_size;
709                 length -= page_size;
710                 if (length <= 0)
711                         break;
712                 if (dma_len > 0)
713                         continue;
714                 BUG_ON(dma_len < 0);
715                 sg = sg_next(sg);
716                 dma_addr = sg_dma_address(sg);
717                 dma_len = sg_dma_len(sg);
718         }
719
720         return true;
721 }
722
723 static int nvme_map_data(struct nvme_dev *dev, struct nvme_iod *iod,
724                 struct nvme_command *cmnd)
725 {
726         struct request *req = iod_get_private(iod);
727         struct request_queue *q = req->q;
728         enum dma_data_direction dma_dir = rq_data_dir(req) ?
729                         DMA_TO_DEVICE : DMA_FROM_DEVICE;
730         int ret = BLK_MQ_RQ_QUEUE_ERROR;
731
732         sg_init_table(iod->sg, req->nr_phys_segments);
733         iod->nents = blk_rq_map_sg(q, req, iod->sg);
734         if (!iod->nents)
735                 goto out;
736
737         ret = BLK_MQ_RQ_QUEUE_BUSY;
738         if (!dma_map_sg(dev->dev, iod->sg, iod->nents, dma_dir))
739                 goto out;
740
741         if (!nvme_setup_prps(dev, iod, blk_rq_bytes(req)))
742                 goto out_unmap;
743
744         ret = BLK_MQ_RQ_QUEUE_ERROR;
745         if (blk_integrity_rq(req)) {
746                 if (blk_rq_count_integrity_sg(q, req->bio) != 1)
747                         goto out_unmap;
748
749                 sg_init_table(iod->meta_sg, 1);
750                 if (blk_rq_map_integrity_sg(q, req->bio, iod->meta_sg) != 1)
751                         goto out_unmap;
752
753                 if (rq_data_dir(req))
754                         nvme_dif_remap(req, nvme_dif_prep);
755
756                 if (!dma_map_sg(dev->dev, iod->meta_sg, 1, dma_dir))
757                         goto out_unmap;
758         }
759
760         cmnd->rw.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
761         cmnd->rw.prp2 = cpu_to_le64(iod->first_dma);
762         if (blk_integrity_rq(req))
763                 cmnd->rw.metadata = cpu_to_le64(sg_dma_address(iod->meta_sg));
764         return BLK_MQ_RQ_QUEUE_OK;
765
766 out_unmap:
767         dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
768 out:
769         return ret;
770 }
771
772 static void nvme_unmap_data(struct nvme_dev *dev, struct nvme_iod *iod)
773 {
774         struct request *req = iod_get_private(iod);
775         enum dma_data_direction dma_dir = rq_data_dir(req) ?
776                         DMA_TO_DEVICE : DMA_FROM_DEVICE;
777
778         if (iod->nents) {
779                 dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
780                 if (blk_integrity_rq(req)) {
781                         if (!rq_data_dir(req))
782                                 nvme_dif_remap(req, nvme_dif_complete);
783                         dma_unmap_sg(dev->dev, iod->meta_sg, 1, dma_dir);
784                 }
785         }
786
787         nvme_free_iod(dev, iod);
788 }
789
790 /*
791  * We reuse the small pool to allocate the 16-byte range here as it is not
792  * worth having a special pool for these or additional cases to handle freeing
793  * the iod.
794  */
795 static int nvme_setup_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,
796                 struct nvme_iod *iod, struct nvme_command *cmnd)
797 {
798         struct request *req = iod_get_private(iod);
799         struct nvme_dsm_range *range;
800
801         range = dma_pool_alloc(nvmeq->dev->prp_small_pool, GFP_ATOMIC,
802                                                 &iod->first_dma);
803         if (!range)
804                 return BLK_MQ_RQ_QUEUE_BUSY;
805         iod_list(iod)[0] = (__le64 *)range;
806         iod->npages = 0;
807
808         range->cattr = cpu_to_le32(0);
809         range->nlb = cpu_to_le32(blk_rq_bytes(req) >> ns->lba_shift);
810         range->slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
811
812         memset(cmnd, 0, sizeof(*cmnd));
813         cmnd->dsm.opcode = nvme_cmd_dsm;
814         cmnd->dsm.nsid = cpu_to_le32(ns->ns_id);
815         cmnd->dsm.prp1 = cpu_to_le64(iod->first_dma);
816         cmnd->dsm.nr = 0;
817         cmnd->dsm.attributes = cpu_to_le32(NVME_DSMGMT_AD);
818         return BLK_MQ_RQ_QUEUE_OK;
819 }
820
821 /*
822  * NOTE: ns is NULL when called on the admin queue.
823  */
824 static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
825                          const struct blk_mq_queue_data *bd)
826 {
827         struct nvme_ns *ns = hctx->queue->queuedata;
828         struct nvme_queue *nvmeq = hctx->driver_data;
829         struct nvme_dev *dev = nvmeq->dev;
830         struct request *req = bd->rq;
831         struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
832         struct nvme_iod *iod;
833         struct nvme_command cmnd;
834         int ret = BLK_MQ_RQ_QUEUE_OK;
835
836         /*
837          * If formated with metadata, require the block layer provide a buffer
838          * unless this namespace is formated such that the metadata can be
839          * stripped/generated by the controller with PRACT=1.
840          */
841         if (ns && ns->ms && !blk_integrity_rq(req)) {
842                 if (!(ns->pi_type && ns->ms == 8) &&
843                                         req->cmd_type != REQ_TYPE_DRV_PRIV) {
844                         blk_mq_complete_request(req, -EFAULT);
845                         return BLK_MQ_RQ_QUEUE_OK;
846                 }
847         }
848
849         iod = nvme_alloc_iod(req, dev, GFP_ATOMIC);
850         if (!iod)
851                 return BLK_MQ_RQ_QUEUE_BUSY;
852
853         if (req->cmd_flags & REQ_DISCARD) {
854                 ret = nvme_setup_discard(nvmeq, ns, iod, &cmnd);
855         } else {
856                 if (req->cmd_type == REQ_TYPE_DRV_PRIV)
857                         memcpy(&cmnd, req->cmd, sizeof(cmnd));
858                 else if (req->cmd_flags & REQ_FLUSH)
859                         nvme_setup_flush(ns, &cmnd);
860                 else
861                         nvme_setup_rw(ns, req, &cmnd);
862
863                 if (req->nr_phys_segments)
864                         ret = nvme_map_data(dev, iod, &cmnd);
865         }
866
867         if (ret)
868                 goto out;
869
870         cmnd.common.command_id = req->tag;
871         nvme_set_info(cmd, iod, req_completion);
872
873         spin_lock_irq(&nvmeq->q_lock);
874         __nvme_submit_cmd(nvmeq, &cmnd);
875         nvme_process_cq(nvmeq);
876         spin_unlock_irq(&nvmeq->q_lock);
877         return BLK_MQ_RQ_QUEUE_OK;
878 out:
879         nvme_free_iod(dev, iod);
880         return ret;
881 }
882
883 static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
884 {
885         u16 head, phase;
886
887         head = nvmeq->cq_head;
888         phase = nvmeq->cq_phase;
889
890         for (;;) {
891                 void *ctx;
892                 nvme_completion_fn fn;
893                 struct nvme_completion cqe = nvmeq->cqes[head];
894                 if ((le16_to_cpu(cqe.status) & 1) != phase)
895                         break;
896                 nvmeq->sq_head = le16_to_cpu(cqe.sq_head);
897                 if (++head == nvmeq->q_depth) {
898                         head = 0;
899                         phase = !phase;
900                 }
901                 if (tag && *tag == cqe.command_id)
902                         *tag = -1;
903                 ctx = nvme_finish_cmd(nvmeq, cqe.command_id, &fn);
904                 fn(nvmeq, ctx, &cqe);
905         }
906
907         /* If the controller ignores the cq head doorbell and continuously
908          * writes to the queue, it is theoretically possible to wrap around
909          * the queue twice and mistakenly return IRQ_NONE.  Linux only
910          * requires that 0.1% of your interrupts are handled, so this isn't
911          * a big problem.
912          */
913         if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
914                 return;
915
916         if (likely(nvmeq->cq_vector >= 0))
917                 writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
918         nvmeq->cq_head = head;
919         nvmeq->cq_phase = phase;
920
921         nvmeq->cqe_seen = 1;
922 }
923
924 static void nvme_process_cq(struct nvme_queue *nvmeq)
925 {
926         __nvme_process_cq(nvmeq, NULL);
927 }
928
929 static irqreturn_t nvme_irq(int irq, void *data)
930 {
931         irqreturn_t result;
932         struct nvme_queue *nvmeq = data;
933         spin_lock(&nvmeq->q_lock);
934         nvme_process_cq(nvmeq);
935         result = nvmeq->cqe_seen ? IRQ_HANDLED : IRQ_NONE;
936         nvmeq->cqe_seen = 0;
937         spin_unlock(&nvmeq->q_lock);
938         return result;
939 }
940
941 static irqreturn_t nvme_irq_check(int irq, void *data)
942 {
943         struct nvme_queue *nvmeq = data;
944         struct nvme_completion cqe = nvmeq->cqes[nvmeq->cq_head];
945         if ((le16_to_cpu(cqe.status) & 1) != nvmeq->cq_phase)
946                 return IRQ_NONE;
947         return IRQ_WAKE_THREAD;
948 }
949
950 static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
951 {
952         struct nvme_queue *nvmeq = hctx->driver_data;
953
954         if ((le16_to_cpu(nvmeq->cqes[nvmeq->cq_head].status) & 1) ==
955             nvmeq->cq_phase) {
956                 spin_lock_irq(&nvmeq->q_lock);
957                 __nvme_process_cq(nvmeq, &tag);
958                 spin_unlock_irq(&nvmeq->q_lock);
959
960                 if (tag == -1)
961                         return 1;
962         }
963
964         return 0;
965 }
966
967 static int nvme_submit_async_admin_req(struct nvme_dev *dev)
968 {
969         struct nvme_queue *nvmeq = dev->queues[0];
970         struct nvme_command c;
971         struct nvme_cmd_info *cmd_info;
972         struct request *req;
973
974         req = blk_mq_alloc_request(dev->ctrl.admin_q, WRITE,
975                         BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED);
976         if (IS_ERR(req))
977                 return PTR_ERR(req);
978
979         req->cmd_flags |= REQ_NO_TIMEOUT;
980         cmd_info = blk_mq_rq_to_pdu(req);
981         nvme_set_info(cmd_info, NULL, async_req_completion);
982
983         memset(&c, 0, sizeof(c));
984         c.common.opcode = nvme_admin_async_event;
985         c.common.command_id = req->tag;
986
987         blk_mq_free_request(req);
988         __nvme_submit_cmd(nvmeq, &c);
989         return 0;
990 }
991
992 static int nvme_submit_admin_async_cmd(struct nvme_dev *dev,
993                         struct nvme_command *cmd,
994                         struct async_cmd_info *cmdinfo, unsigned timeout)
995 {
996         struct nvme_queue *nvmeq = dev->queues[0];
997         struct request *req;
998         struct nvme_cmd_info *cmd_rq;
999
1000         req = blk_mq_alloc_request(dev->ctrl.admin_q, WRITE, 0);
1001         if (IS_ERR(req))
1002                 return PTR_ERR(req);
1003
1004         req->timeout = timeout;
1005         cmd_rq = blk_mq_rq_to_pdu(req);
1006         cmdinfo->req = req;
1007         nvme_set_info(cmd_rq, cmdinfo, async_completion);
1008         cmdinfo->status = -EINTR;
1009
1010         cmd->common.command_id = req->tag;
1011
1012         nvme_submit_cmd(nvmeq, cmd);
1013         return 0;
1014 }
1015
1016 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
1017 {
1018         struct nvme_command c;
1019
1020         memset(&c, 0, sizeof(c));
1021         c.delete_queue.opcode = opcode;
1022         c.delete_queue.qid = cpu_to_le16(id);
1023
1024         return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1025 }
1026
1027 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
1028                                                 struct nvme_queue *nvmeq)
1029 {
1030         struct nvme_command c;
1031         int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
1032
1033         /*
1034          * Note: we (ab)use the fact the the prp fields survive if no data
1035          * is attached to the request.
1036          */
1037         memset(&c, 0, sizeof(c));
1038         c.create_cq.opcode = nvme_admin_create_cq;
1039         c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
1040         c.create_cq.cqid = cpu_to_le16(qid);
1041         c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
1042         c.create_cq.cq_flags = cpu_to_le16(flags);
1043         c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
1044
1045         return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1046 }
1047
1048 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
1049                                                 struct nvme_queue *nvmeq)
1050 {
1051         struct nvme_command c;
1052         int flags = NVME_QUEUE_PHYS_CONTIG | NVME_SQ_PRIO_MEDIUM;
1053
1054         /*
1055          * Note: we (ab)use the fact the the prp fields survive if no data
1056          * is attached to the request.
1057          */
1058         memset(&c, 0, sizeof(c));
1059         c.create_sq.opcode = nvme_admin_create_sq;
1060         c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
1061         c.create_sq.sqid = cpu_to_le16(qid);
1062         c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
1063         c.create_sq.sq_flags = cpu_to_le16(flags);
1064         c.create_sq.cqid = cpu_to_le16(qid);
1065
1066         return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1067 }
1068
1069 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
1070 {
1071         return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
1072 }
1073
1074 static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
1075 {
1076         return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
1077 }
1078
1079 /**
1080  * nvme_abort_req - Attempt aborting a request
1081  *
1082  * Schedule controller reset if the command was already aborted once before and
1083  * still hasn't been returned to the driver, or if this is the admin queue.
1084  */
1085 static void nvme_abort_req(struct request *req)
1086 {
1087         struct nvme_cmd_info *cmd_rq = blk_mq_rq_to_pdu(req);
1088         struct nvme_queue *nvmeq = cmd_rq->nvmeq;
1089         struct nvme_dev *dev = nvmeq->dev;
1090         struct request *abort_req;
1091         struct nvme_cmd_info *abort_cmd;
1092         struct nvme_command cmd;
1093
1094         if (!nvmeq->qid || cmd_rq->aborted) {
1095                 spin_lock(&dev_list_lock);
1096                 if (!__nvme_reset(dev)) {
1097                         dev_warn(dev->dev,
1098                                  "I/O %d QID %d timeout, reset controller\n",
1099                                  req->tag, nvmeq->qid);
1100                 }
1101                 spin_unlock(&dev_list_lock);
1102                 return;
1103         }
1104
1105         if (!dev->ctrl.abort_limit)
1106                 return;
1107
1108         abort_req = blk_mq_alloc_request(dev->ctrl.admin_q, WRITE,
1109                         BLK_MQ_REQ_NOWAIT);
1110         if (IS_ERR(abort_req))
1111                 return;
1112
1113         abort_cmd = blk_mq_rq_to_pdu(abort_req);
1114         nvme_set_info(abort_cmd, abort_req, abort_completion);
1115
1116         memset(&cmd, 0, sizeof(cmd));
1117         cmd.abort.opcode = nvme_admin_abort_cmd;
1118         cmd.abort.cid = req->tag;
1119         cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
1120         cmd.abort.command_id = abort_req->tag;
1121
1122         --dev->ctrl.abort_limit;
1123         cmd_rq->aborted = 1;
1124
1125         dev_warn(nvmeq->q_dmadev, "Aborting I/O %d QID %d\n", req->tag,
1126                                                         nvmeq->qid);
1127         nvme_submit_cmd(dev->queues[0], &cmd);
1128 }
1129
1130 static void nvme_cancel_queue_ios(struct request *req, void *data, bool reserved)
1131 {
1132         struct nvme_queue *nvmeq = data;
1133         void *ctx;
1134         nvme_completion_fn fn;
1135         struct nvme_cmd_info *cmd;
1136         struct nvme_completion cqe;
1137
1138         if (!blk_mq_request_started(req))
1139                 return;
1140
1141         cmd = blk_mq_rq_to_pdu(req);
1142
1143         if (cmd->ctx == CMD_CTX_CANCELLED)
1144                 return;
1145
1146         if (blk_queue_dying(req->q))
1147                 cqe.status = cpu_to_le16((NVME_SC_ABORT_REQ | NVME_SC_DNR) << 1);
1148         else
1149                 cqe.status = cpu_to_le16(NVME_SC_ABORT_REQ << 1);
1150
1151
1152         dev_warn(nvmeq->q_dmadev, "Cancelling I/O %d QID %d\n",
1153                                                 req->tag, nvmeq->qid);
1154         ctx = cancel_cmd_info(cmd, &fn);
1155         fn(nvmeq, ctx, &cqe);
1156 }
1157
1158 static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
1159 {
1160         struct nvme_cmd_info *cmd = blk_mq_rq_to_pdu(req);
1161         struct nvme_queue *nvmeq = cmd->nvmeq;
1162
1163         dev_warn(nvmeq->q_dmadev, "Timeout I/O %d QID %d\n", req->tag,
1164                                                         nvmeq->qid);
1165         spin_lock_irq(&nvmeq->q_lock);
1166         nvme_abort_req(req);
1167         spin_unlock_irq(&nvmeq->q_lock);
1168
1169         /*
1170          * The aborted req will be completed on receiving the abort req.
1171          * We enable the timer again. If hit twice, it'll cause a device reset,
1172          * as the device then is in a faulty state.
1173          */
1174         return BLK_EH_RESET_TIMER;
1175 }
1176
1177 static void nvme_free_queue(struct nvme_queue *nvmeq)
1178 {
1179         dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
1180                                 (void *)nvmeq->cqes, nvmeq->cq_dma_addr);
1181         if (nvmeq->sq_cmds)
1182                 dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
1183                                         nvmeq->sq_cmds, nvmeq->sq_dma_addr);
1184         kfree(nvmeq);
1185 }
1186
1187 static void nvme_free_queues(struct nvme_dev *dev, int lowest)
1188 {
1189         int i;
1190
1191         for (i = dev->queue_count - 1; i >= lowest; i--) {
1192                 struct nvme_queue *nvmeq = dev->queues[i];
1193                 dev->queue_count--;
1194                 dev->queues[i] = NULL;
1195                 nvme_free_queue(nvmeq);
1196         }
1197 }
1198
1199 /**
1200  * nvme_suspend_queue - put queue into suspended state
1201  * @nvmeq - queue to suspend
1202  */
1203 static int nvme_suspend_queue(struct nvme_queue *nvmeq)
1204 {
1205         int vector;
1206
1207         spin_lock_irq(&nvmeq->q_lock);
1208         if (nvmeq->cq_vector == -1) {
1209                 spin_unlock_irq(&nvmeq->q_lock);
1210                 return 1;
1211         }
1212         vector = nvmeq->dev->entry[nvmeq->cq_vector].vector;
1213         nvmeq->dev->online_queues--;
1214         nvmeq->cq_vector = -1;
1215         spin_unlock_irq(&nvmeq->q_lock);
1216
1217         if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
1218                 blk_mq_freeze_queue_start(nvmeq->dev->ctrl.admin_q);
1219
1220         irq_set_affinity_hint(vector, NULL);
1221         free_irq(vector, nvmeq);
1222
1223         return 0;
1224 }
1225
1226 static void nvme_clear_queue(struct nvme_queue *nvmeq)
1227 {
1228         spin_lock_irq(&nvmeq->q_lock);
1229         if (nvmeq->tags && *nvmeq->tags)
1230                 blk_mq_all_tag_busy_iter(*nvmeq->tags, nvme_cancel_queue_ios, nvmeq);
1231         spin_unlock_irq(&nvmeq->q_lock);
1232 }
1233
1234 static void nvme_disable_queue(struct nvme_dev *dev, int qid)
1235 {
1236         struct nvme_queue *nvmeq = dev->queues[qid];
1237
1238         if (!nvmeq)
1239                 return;
1240         if (nvme_suspend_queue(nvmeq))
1241                 return;
1242
1243         /* Don't tell the adapter to delete the admin queue.
1244          * Don't tell a removed adapter to delete IO queues. */
1245         if (qid && readl(dev->bar + NVME_REG_CSTS) != -1) {
1246                 adapter_delete_sq(dev, qid);
1247                 adapter_delete_cq(dev, qid);
1248         }
1249
1250         spin_lock_irq(&nvmeq->q_lock);
1251         nvme_process_cq(nvmeq);
1252         spin_unlock_irq(&nvmeq->q_lock);
1253 }
1254
1255 static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues,
1256                                 int entry_size)
1257 {
1258         int q_depth = dev->q_depth;
1259         unsigned q_size_aligned = roundup(q_depth * entry_size,
1260                                           dev->ctrl.page_size);
1261
1262         if (q_size_aligned * nr_io_queues > dev->cmb_size) {
1263                 u64 mem_per_q = div_u64(dev->cmb_size, nr_io_queues);
1264                 mem_per_q = round_down(mem_per_q, dev->ctrl.page_size);
1265                 q_depth = div_u64(mem_per_q, entry_size);
1266
1267                 /*
1268                  * Ensure the reduced q_depth is above some threshold where it
1269                  * would be better to map queues in system memory with the
1270                  * original depth
1271                  */
1272                 if (q_depth < 64)
1273                         return -ENOMEM;
1274         }
1275
1276         return q_depth;
1277 }
1278
1279 static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
1280                                 int qid, int depth)
1281 {
1282         if (qid && dev->cmb && use_cmb_sqes && NVME_CMB_SQS(dev->cmbsz)) {
1283                 unsigned offset = (qid - 1) * roundup(SQ_SIZE(depth),
1284                                                       dev->ctrl.page_size);
1285                 nvmeq->sq_dma_addr = dev->cmb_dma_addr + offset;
1286                 nvmeq->sq_cmds_io = dev->cmb + offset;
1287         } else {
1288                 nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(depth),
1289                                         &nvmeq->sq_dma_addr, GFP_KERNEL);
1290                 if (!nvmeq->sq_cmds)
1291                         return -ENOMEM;
1292         }
1293
1294         return 0;
1295 }
1296
1297 static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
1298                                                         int depth)
1299 {
1300         struct nvme_queue *nvmeq = kzalloc(sizeof(*nvmeq), GFP_KERNEL);
1301         if (!nvmeq)
1302                 return NULL;
1303
1304         nvmeq->cqes = dma_zalloc_coherent(dev->dev, CQ_SIZE(depth),
1305                                           &nvmeq->cq_dma_addr, GFP_KERNEL);
1306         if (!nvmeq->cqes)
1307                 goto free_nvmeq;
1308
1309         if (nvme_alloc_sq_cmds(dev, nvmeq, qid, depth))
1310                 goto free_cqdma;
1311
1312         nvmeq->q_dmadev = dev->dev;
1313         nvmeq->dev = dev;
1314         snprintf(nvmeq->irqname, sizeof(nvmeq->irqname), "nvme%dq%d",
1315                         dev->ctrl.instance, qid);
1316         spin_lock_init(&nvmeq->q_lock);
1317         nvmeq->cq_head = 0;
1318         nvmeq->cq_phase = 1;
1319         nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1320         nvmeq->q_depth = depth;
1321         nvmeq->qid = qid;
1322         nvmeq->cq_vector = -1;
1323         dev->queues[qid] = nvmeq;
1324
1325         /* make sure queue descriptor is set before queue count, for kthread */
1326         mb();
1327         dev->queue_count++;
1328
1329         return nvmeq;
1330
1331  free_cqdma:
1332         dma_free_coherent(dev->dev, CQ_SIZE(depth), (void *)nvmeq->cqes,
1333                                                         nvmeq->cq_dma_addr);
1334  free_nvmeq:
1335         kfree(nvmeq);
1336         return NULL;
1337 }
1338
1339 static int queue_request_irq(struct nvme_dev *dev, struct nvme_queue *nvmeq,
1340                                                         const char *name)
1341 {
1342         if (use_threaded_interrupts)
1343                 return request_threaded_irq(dev->entry[nvmeq->cq_vector].vector,
1344                                         nvme_irq_check, nvme_irq, IRQF_SHARED,
1345                                         name, nvmeq);
1346         return request_irq(dev->entry[nvmeq->cq_vector].vector, nvme_irq,
1347                                 IRQF_SHARED, name, nvmeq);
1348 }
1349
1350 static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
1351 {
1352         struct nvme_dev *dev = nvmeq->dev;
1353
1354         spin_lock_irq(&nvmeq->q_lock);
1355         nvmeq->sq_tail = 0;
1356         nvmeq->cq_head = 0;
1357         nvmeq->cq_phase = 1;
1358         nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1359         memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth));
1360         dev->online_queues++;
1361         spin_unlock_irq(&nvmeq->q_lock);
1362 }
1363
1364 static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
1365 {
1366         struct nvme_dev *dev = nvmeq->dev;
1367         int result;
1368
1369         nvmeq->cq_vector = qid - 1;
1370         result = adapter_alloc_cq(dev, qid, nvmeq);
1371         if (result < 0)
1372                 return result;
1373
1374         result = adapter_alloc_sq(dev, qid, nvmeq);
1375         if (result < 0)
1376                 goto release_cq;
1377
1378         result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
1379         if (result < 0)
1380                 goto release_sq;
1381
1382         nvme_init_queue(nvmeq, qid);
1383         return result;
1384
1385  release_sq:
1386         adapter_delete_sq(dev, qid);
1387  release_cq:
1388         adapter_delete_cq(dev, qid);
1389         return result;
1390 }
1391
1392 static struct blk_mq_ops nvme_mq_admin_ops = {
1393         .queue_rq       = nvme_queue_rq,
1394         .map_queue      = blk_mq_map_queue,
1395         .init_hctx      = nvme_admin_init_hctx,
1396         .exit_hctx      = nvme_admin_exit_hctx,
1397         .init_request   = nvme_admin_init_request,
1398         .timeout        = nvme_timeout,
1399 };
1400
1401 static struct blk_mq_ops nvme_mq_ops = {
1402         .queue_rq       = nvme_queue_rq,
1403         .map_queue      = blk_mq_map_queue,
1404         .init_hctx      = nvme_init_hctx,
1405         .init_request   = nvme_init_request,
1406         .timeout        = nvme_timeout,
1407         .poll           = nvme_poll,
1408 };
1409
1410 static void nvme_dev_remove_admin(struct nvme_dev *dev)
1411 {
1412         if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q)) {
1413                 blk_cleanup_queue(dev->ctrl.admin_q);
1414                 blk_mq_free_tag_set(&dev->admin_tagset);
1415         }
1416 }
1417
1418 static int nvme_alloc_admin_tags(struct nvme_dev *dev)
1419 {
1420         if (!dev->ctrl.admin_q) {
1421                 dev->admin_tagset.ops = &nvme_mq_admin_ops;
1422                 dev->admin_tagset.nr_hw_queues = 1;
1423                 dev->admin_tagset.queue_depth = NVME_AQ_DEPTH - 1;
1424                 dev->admin_tagset.reserved_tags = 1;
1425                 dev->admin_tagset.timeout = ADMIN_TIMEOUT;
1426                 dev->admin_tagset.numa_node = dev_to_node(dev->dev);
1427                 dev->admin_tagset.cmd_size = nvme_cmd_size(dev);
1428                 dev->admin_tagset.driver_data = dev;
1429
1430                 if (blk_mq_alloc_tag_set(&dev->admin_tagset))
1431                         return -ENOMEM;
1432
1433                 dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
1434                 if (IS_ERR(dev->ctrl.admin_q)) {
1435                         blk_mq_free_tag_set(&dev->admin_tagset);
1436                         return -ENOMEM;
1437                 }
1438                 if (!blk_get_queue(dev->ctrl.admin_q)) {
1439                         nvme_dev_remove_admin(dev);
1440                         dev->ctrl.admin_q = NULL;
1441                         return -ENODEV;
1442                 }
1443         } else
1444                 blk_mq_unfreeze_queue(dev->ctrl.admin_q);
1445
1446         return 0;
1447 }
1448
1449 static int nvme_configure_admin_queue(struct nvme_dev *dev)
1450 {
1451         int result;
1452         u32 aqa;
1453         u64 cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
1454         struct nvme_queue *nvmeq;
1455
1456         dev->subsystem = readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 1) ?
1457                                                 NVME_CAP_NSSRC(cap) : 0;
1458
1459         if (dev->subsystem &&
1460             (readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_NSSRO))
1461                 writel(NVME_CSTS_NSSRO, dev->bar + NVME_REG_CSTS);
1462
1463         result = nvme_disable_ctrl(&dev->ctrl, cap);
1464         if (result < 0)
1465                 return result;
1466
1467         nvmeq = dev->queues[0];
1468         if (!nvmeq) {
1469                 nvmeq = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH);
1470                 if (!nvmeq)
1471                         return -ENOMEM;
1472         }
1473
1474         aqa = nvmeq->q_depth - 1;
1475         aqa |= aqa << 16;
1476
1477         writel(aqa, dev->bar + NVME_REG_AQA);
1478         lo_hi_writeq(nvmeq->sq_dma_addr, dev->bar + NVME_REG_ASQ);
1479         lo_hi_writeq(nvmeq->cq_dma_addr, dev->bar + NVME_REG_ACQ);
1480
1481         result = nvme_enable_ctrl(&dev->ctrl, cap);
1482         if (result)
1483                 goto free_nvmeq;
1484
1485         nvmeq->cq_vector = 0;
1486         result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
1487         if (result) {
1488                 nvmeq->cq_vector = -1;
1489                 goto free_nvmeq;
1490         }
1491
1492         return result;
1493
1494  free_nvmeq:
1495         nvme_free_queues(dev, 0);
1496         return result;
1497 }
1498
1499 static int nvme_kthread(void *data)
1500 {
1501         struct nvme_dev *dev, *next;
1502
1503         while (!kthread_should_stop()) {
1504                 set_current_state(TASK_INTERRUPTIBLE);
1505                 spin_lock(&dev_list_lock);
1506                 list_for_each_entry_safe(dev, next, &dev_list, node) {
1507                         int i;
1508                         u32 csts = readl(dev->bar + NVME_REG_CSTS);
1509
1510                         if ((dev->subsystem && (csts & NVME_CSTS_NSSRO)) ||
1511                                                         csts & NVME_CSTS_CFS) {
1512                                 if (!__nvme_reset(dev)) {
1513                                         dev_warn(dev->dev,
1514                                                 "Failed status: %x, reset controller\n",
1515                                                 readl(dev->bar + NVME_REG_CSTS));
1516                                 }
1517                                 continue;
1518                         }
1519                         for (i = 0; i < dev->queue_count; i++) {
1520                                 struct nvme_queue *nvmeq = dev->queues[i];
1521                                 if (!nvmeq)
1522                                         continue;
1523                                 spin_lock_irq(&nvmeq->q_lock);
1524                                 nvme_process_cq(nvmeq);
1525
1526                                 while (i == 0 && dev->ctrl.event_limit > 0) {
1527                                         if (nvme_submit_async_admin_req(dev))
1528                                                 break;
1529                                         dev->ctrl.event_limit--;
1530                                 }
1531                                 spin_unlock_irq(&nvmeq->q_lock);
1532                         }
1533                 }
1534                 spin_unlock(&dev_list_lock);
1535                 schedule_timeout(round_jiffies_relative(HZ));
1536         }
1537         return 0;
1538 }
1539
1540 static int nvme_create_io_queues(struct nvme_dev *dev)
1541 {
1542         unsigned i;
1543         int ret = 0;
1544
1545         for (i = dev->queue_count; i <= dev->max_qid; i++) {
1546                 if (!nvme_alloc_queue(dev, i, dev->q_depth)) {
1547                         ret = -ENOMEM;
1548                         break;
1549                 }
1550         }
1551
1552         for (i = dev->online_queues; i <= dev->queue_count - 1; i++) {
1553                 ret = nvme_create_queue(dev->queues[i], i);
1554                 if (ret) {
1555                         nvme_free_queues(dev, i);
1556                         break;
1557                 }
1558         }
1559
1560         /*
1561          * Ignore failing Create SQ/CQ commands, we can continue with less
1562          * than the desired aount of queues, and even a controller without
1563          * I/O queues an still be used to issue admin commands.  This might
1564          * be useful to upgrade a buggy firmware for example.
1565          */
1566         return ret >= 0 ? 0 : ret;
1567 }
1568
1569 static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
1570 {
1571         u64 szu, size, offset;
1572         u32 cmbloc;
1573         resource_size_t bar_size;
1574         struct pci_dev *pdev = to_pci_dev(dev->dev);
1575         void __iomem *cmb;
1576         dma_addr_t dma_addr;
1577
1578         if (!use_cmb_sqes)
1579                 return NULL;
1580
1581         dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
1582         if (!(NVME_CMB_SZ(dev->cmbsz)))
1583                 return NULL;
1584
1585         cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
1586
1587         szu = (u64)1 << (12 + 4 * NVME_CMB_SZU(dev->cmbsz));
1588         size = szu * NVME_CMB_SZ(dev->cmbsz);
1589         offset = szu * NVME_CMB_OFST(cmbloc);
1590         bar_size = pci_resource_len(pdev, NVME_CMB_BIR(cmbloc));
1591
1592         if (offset > bar_size)
1593                 return NULL;
1594
1595         /*
1596          * Controllers may support a CMB size larger than their BAR,
1597          * for example, due to being behind a bridge. Reduce the CMB to
1598          * the reported size of the BAR
1599          */
1600         if (size > bar_size - offset)
1601                 size = bar_size - offset;
1602
1603         dma_addr = pci_resource_start(pdev, NVME_CMB_BIR(cmbloc)) + offset;
1604         cmb = ioremap_wc(dma_addr, size);
1605         if (!cmb)
1606                 return NULL;
1607
1608         dev->cmb_dma_addr = dma_addr;
1609         dev->cmb_size = size;
1610         return cmb;
1611 }
1612
1613 static inline void nvme_release_cmb(struct nvme_dev *dev)
1614 {
1615         if (dev->cmb) {
1616                 iounmap(dev->cmb);
1617                 dev->cmb = NULL;
1618         }
1619 }
1620
1621 static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
1622 {
1623         return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride);
1624 }
1625
1626 static int nvme_setup_io_queues(struct nvme_dev *dev)
1627 {
1628         struct nvme_queue *adminq = dev->queues[0];
1629         struct pci_dev *pdev = to_pci_dev(dev->dev);
1630         int result, i, vecs, nr_io_queues, size;
1631
1632         nr_io_queues = num_possible_cpus();
1633         result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
1634         if (result < 0)
1635                 return result;
1636
1637         /*
1638          * Degraded controllers might return an error when setting the queue
1639          * count.  We still want to be able to bring them online and offer
1640          * access to the admin queue, as that might be only way to fix them up.
1641          */
1642         if (result > 0) {
1643                 dev_err(dev->dev, "Could not set queue count (%d)\n", result);
1644                 nr_io_queues = 0;
1645                 result = 0;
1646         }
1647
1648         if (dev->cmb && NVME_CMB_SQS(dev->cmbsz)) {
1649                 result = nvme_cmb_qdepth(dev, nr_io_queues,
1650                                 sizeof(struct nvme_command));
1651                 if (result > 0)
1652                         dev->q_depth = result;
1653                 else
1654                         nvme_release_cmb(dev);
1655         }
1656
1657         size = db_bar_size(dev, nr_io_queues);
1658         if (size > 8192) {
1659                 iounmap(dev->bar);
1660                 do {
1661                         dev->bar = ioremap(pci_resource_start(pdev, 0), size);
1662                         if (dev->bar)
1663                                 break;
1664                         if (!--nr_io_queues)
1665                                 return -ENOMEM;
1666                         size = db_bar_size(dev, nr_io_queues);
1667                 } while (1);
1668                 dev->dbs = dev->bar + 4096;
1669                 adminq->q_db = dev->dbs;
1670         }
1671
1672         /* Deregister the admin queue's interrupt */
1673         free_irq(dev->entry[0].vector, adminq);
1674
1675         /*
1676          * If we enable msix early due to not intx, disable it again before
1677          * setting up the full range we need.
1678          */
1679         if (!pdev->irq)
1680                 pci_disable_msix(pdev);
1681
1682         for (i = 0; i < nr_io_queues; i++)
1683                 dev->entry[i].entry = i;
1684         vecs = pci_enable_msix_range(pdev, dev->entry, 1, nr_io_queues);
1685         if (vecs < 0) {
1686                 vecs = pci_enable_msi_range(pdev, 1, min(nr_io_queues, 32));
1687                 if (vecs < 0) {
1688                         vecs = 1;
1689                 } else {
1690                         for (i = 0; i < vecs; i++)
1691                                 dev->entry[i].vector = i + pdev->irq;
1692                 }
1693         }
1694
1695         /*
1696          * Should investigate if there's a performance win from allocating
1697          * more queues than interrupt vectors; it might allow the submission
1698          * path to scale better, even if the receive path is limited by the
1699          * number of interrupts.
1700          */
1701         nr_io_queues = vecs;
1702         dev->max_qid = nr_io_queues;
1703
1704         result = queue_request_irq(dev, adminq, adminq->irqname);
1705         if (result) {
1706                 adminq->cq_vector = -1;
1707                 goto free_queues;
1708         }
1709
1710         /* Free previously allocated queues that are no longer usable */
1711         nvme_free_queues(dev, nr_io_queues + 1);
1712         return nvme_create_io_queues(dev);
1713
1714  free_queues:
1715         nvme_free_queues(dev, 1);
1716         return result;
1717 }
1718
1719 static void nvme_set_irq_hints(struct nvme_dev *dev)
1720 {
1721         struct nvme_queue *nvmeq;
1722         int i;
1723
1724         for (i = 0; i < dev->online_queues; i++) {
1725                 nvmeq = dev->queues[i];
1726
1727                 if (!nvmeq->tags || !(*nvmeq->tags))
1728                         continue;
1729
1730                 irq_set_affinity_hint(dev->entry[nvmeq->cq_vector].vector,
1731                                         blk_mq_tags_cpumask(*nvmeq->tags));
1732         }
1733 }
1734
1735 static void nvme_dev_scan(struct work_struct *work)
1736 {
1737         struct nvme_dev *dev = container_of(work, struct nvme_dev, scan_work);
1738
1739         if (!dev->tagset.tags)
1740                 return;
1741         nvme_scan_namespaces(&dev->ctrl);
1742         nvme_set_irq_hints(dev);
1743 }
1744
1745 /*
1746  * Return: error value if an error occurred setting up the queues or calling
1747  * Identify Device.  0 if these succeeded, even if adding some of the
1748  * namespaces failed.  At the moment, these failures are silent.  TBD which
1749  * failures should be reported.
1750  */
1751 static int nvme_dev_add(struct nvme_dev *dev)
1752 {
1753         if (!dev->ctrl.tagset) {
1754                 dev->tagset.ops = &nvme_mq_ops;
1755                 dev->tagset.nr_hw_queues = dev->online_queues - 1;
1756                 dev->tagset.timeout = NVME_IO_TIMEOUT;
1757                 dev->tagset.numa_node = dev_to_node(dev->dev);
1758                 dev->tagset.queue_depth =
1759                                 min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH) - 1;
1760                 dev->tagset.cmd_size = nvme_cmd_size(dev);
1761                 dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
1762                 dev->tagset.driver_data = dev;
1763
1764                 if (blk_mq_alloc_tag_set(&dev->tagset))
1765                         return 0;
1766                 dev->ctrl.tagset = &dev->tagset;
1767         }
1768         schedule_work(&dev->scan_work);
1769         return 0;
1770 }
1771
1772 static int nvme_dev_map(struct nvme_dev *dev)
1773 {
1774         u64 cap;
1775         int bars, result = -ENOMEM;
1776         struct pci_dev *pdev = to_pci_dev(dev->dev);
1777
1778         if (pci_enable_device_mem(pdev))
1779                 return result;
1780
1781         dev->entry[0].vector = pdev->irq;
1782         pci_set_master(pdev);
1783         bars = pci_select_bars(pdev, IORESOURCE_MEM);
1784         if (!bars)
1785                 goto disable_pci;
1786
1787         if (pci_request_selected_regions(pdev, bars, "nvme"))
1788                 goto disable_pci;
1789
1790         if (dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(64)) &&
1791             dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(32)))
1792                 goto disable;
1793
1794         dev->bar = ioremap(pci_resource_start(pdev, 0), 8192);
1795         if (!dev->bar)
1796                 goto disable;
1797
1798         if (readl(dev->bar + NVME_REG_CSTS) == -1) {
1799                 result = -ENODEV;
1800                 goto unmap;
1801         }
1802
1803         /*
1804          * Some devices don't advertse INTx interrupts, pre-enable a single
1805          * MSIX vec for setup. We'll adjust this later.
1806          */
1807         if (!pdev->irq) {
1808                 result = pci_enable_msix(pdev, dev->entry, 1);
1809                 if (result < 0)
1810                         goto unmap;
1811         }
1812
1813         cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
1814
1815         dev->q_depth = min_t(int, NVME_CAP_MQES(cap) + 1, NVME_Q_DEPTH);
1816         dev->db_stride = 1 << NVME_CAP_STRIDE(cap);
1817         dev->dbs = dev->bar + 4096;
1818         if (readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 2))
1819                 dev->cmb = nvme_map_cmb(dev);
1820
1821         return 0;
1822
1823  unmap:
1824         iounmap(dev->bar);
1825         dev->bar = NULL;
1826  disable:
1827         pci_release_regions(pdev);
1828  disable_pci:
1829         pci_disable_device(pdev);
1830         return result;
1831 }
1832
1833 static void nvme_dev_unmap(struct nvme_dev *dev)
1834 {
1835         struct pci_dev *pdev = to_pci_dev(dev->dev);
1836
1837         if (pdev->msi_enabled)
1838                 pci_disable_msi(pdev);
1839         else if (pdev->msix_enabled)
1840                 pci_disable_msix(pdev);
1841
1842         if (dev->bar) {
1843                 iounmap(dev->bar);
1844                 dev->bar = NULL;
1845                 pci_release_regions(pdev);
1846         }
1847
1848         if (pci_is_enabled(pdev))
1849                 pci_disable_device(pdev);
1850 }
1851
1852 struct nvme_delq_ctx {
1853         struct task_struct *waiter;
1854         struct kthread_worker *worker;
1855         atomic_t refcount;
1856 };
1857
1858 static void nvme_wait_dq(struct nvme_delq_ctx *dq, struct nvme_dev *dev)
1859 {
1860         dq->waiter = current;
1861         mb();
1862
1863         for (;;) {
1864                 set_current_state(TASK_KILLABLE);
1865                 if (!atomic_read(&dq->refcount))
1866                         break;
1867                 if (!schedule_timeout(ADMIN_TIMEOUT) ||
1868                                         fatal_signal_pending(current)) {
1869                         /*
1870                          * Disable the controller first since we can't trust it
1871                          * at this point, but leave the admin queue enabled
1872                          * until all queue deletion requests are flushed.
1873                          * FIXME: This may take a while if there are more h/w
1874                          * queues than admin tags.
1875                          */
1876                         set_current_state(TASK_RUNNING);
1877                         nvme_disable_ctrl(&dev->ctrl,
1878                                 lo_hi_readq(dev->bar + NVME_REG_CAP));
1879                         nvme_clear_queue(dev->queues[0]);
1880                         flush_kthread_worker(dq->worker);
1881                         nvme_disable_queue(dev, 0);
1882                         return;
1883                 }
1884         }
1885         set_current_state(TASK_RUNNING);
1886 }
1887
1888 static void nvme_put_dq(struct nvme_delq_ctx *dq)
1889 {
1890         atomic_dec(&dq->refcount);
1891         if (dq->waiter)
1892                 wake_up_process(dq->waiter);
1893 }
1894
1895 static struct nvme_delq_ctx *nvme_get_dq(struct nvme_delq_ctx *dq)
1896 {
1897         atomic_inc(&dq->refcount);
1898         return dq;
1899 }
1900
1901 static void nvme_del_queue_end(struct nvme_queue *nvmeq)
1902 {
1903         struct nvme_delq_ctx *dq = nvmeq->cmdinfo.ctx;
1904         nvme_put_dq(dq);
1905
1906         spin_lock_irq(&nvmeq->q_lock);
1907         nvme_process_cq(nvmeq);
1908         spin_unlock_irq(&nvmeq->q_lock);
1909 }
1910
1911 static int adapter_async_del_queue(struct nvme_queue *nvmeq, u8 opcode,
1912                                                 kthread_work_func_t fn)
1913 {
1914         struct nvme_command c;
1915
1916         memset(&c, 0, sizeof(c));
1917         c.delete_queue.opcode = opcode;
1918         c.delete_queue.qid = cpu_to_le16(nvmeq->qid);
1919
1920         init_kthread_work(&nvmeq->cmdinfo.work, fn);
1921         return nvme_submit_admin_async_cmd(nvmeq->dev, &c, &nvmeq->cmdinfo,
1922                                                                 ADMIN_TIMEOUT);
1923 }
1924
1925 static void nvme_del_cq_work_handler(struct kthread_work *work)
1926 {
1927         struct nvme_queue *nvmeq = container_of(work, struct nvme_queue,
1928                                                         cmdinfo.work);
1929         nvme_del_queue_end(nvmeq);
1930 }
1931
1932 static int nvme_delete_cq(struct nvme_queue *nvmeq)
1933 {
1934         return adapter_async_del_queue(nvmeq, nvme_admin_delete_cq,
1935                                                 nvme_del_cq_work_handler);
1936 }
1937
1938 static void nvme_del_sq_work_handler(struct kthread_work *work)
1939 {
1940         struct nvme_queue *nvmeq = container_of(work, struct nvme_queue,
1941                                                         cmdinfo.work);
1942         int status = nvmeq->cmdinfo.status;
1943
1944         if (!status)
1945                 status = nvme_delete_cq(nvmeq);
1946         if (status)
1947                 nvme_del_queue_end(nvmeq);
1948 }
1949
1950 static int nvme_delete_sq(struct nvme_queue *nvmeq)
1951 {
1952         return adapter_async_del_queue(nvmeq, nvme_admin_delete_sq,
1953                                                 nvme_del_sq_work_handler);
1954 }
1955
1956 static void nvme_del_queue_start(struct kthread_work *work)
1957 {
1958         struct nvme_queue *nvmeq = container_of(work, struct nvme_queue,
1959                                                         cmdinfo.work);
1960         if (nvme_delete_sq(nvmeq))
1961                 nvme_del_queue_end(nvmeq);
1962 }
1963
1964 static void nvme_disable_io_queues(struct nvme_dev *dev)
1965 {
1966         int i;
1967         DEFINE_KTHREAD_WORKER_ONSTACK(worker);
1968         struct nvme_delq_ctx dq;
1969         struct task_struct *kworker_task = kthread_run(kthread_worker_fn,
1970                                         &worker, "nvme%d", dev->ctrl.instance);
1971
1972         if (IS_ERR(kworker_task)) {
1973                 dev_err(dev->dev,
1974                         "Failed to create queue del task\n");
1975                 for (i = dev->queue_count - 1; i > 0; i--)
1976                         nvme_disable_queue(dev, i);
1977                 return;
1978         }
1979
1980         dq.waiter = NULL;
1981         atomic_set(&dq.refcount, 0);
1982         dq.worker = &worker;
1983         for (i = dev->queue_count - 1; i > 0; i--) {
1984                 struct nvme_queue *nvmeq = dev->queues[i];
1985
1986                 if (nvme_suspend_queue(nvmeq))
1987                         continue;
1988                 nvmeq->cmdinfo.ctx = nvme_get_dq(&dq);
1989                 nvmeq->cmdinfo.worker = dq.worker;
1990                 init_kthread_work(&nvmeq->cmdinfo.work, nvme_del_queue_start);
1991                 queue_kthread_work(dq.worker, &nvmeq->cmdinfo.work);
1992         }
1993         nvme_wait_dq(&dq, dev);
1994         kthread_stop(kworker_task);
1995 }
1996
1997 static int nvme_dev_list_add(struct nvme_dev *dev)
1998 {
1999         bool start_thread = false;
2000
2001         spin_lock(&dev_list_lock);
2002         if (list_empty(&dev_list) && IS_ERR_OR_NULL(nvme_thread)) {
2003                 start_thread = true;
2004                 nvme_thread = NULL;
2005         }
2006         list_add(&dev->node, &dev_list);
2007         spin_unlock(&dev_list_lock);
2008
2009         if (start_thread) {
2010                 nvme_thread = kthread_run(nvme_kthread, NULL, "nvme");
2011                 wake_up_all(&nvme_kthread_wait);
2012         } else
2013                 wait_event_killable(nvme_kthread_wait, nvme_thread);
2014
2015         if (IS_ERR_OR_NULL(nvme_thread))
2016                 return nvme_thread ? PTR_ERR(nvme_thread) : -EINTR;
2017
2018         return 0;
2019 }
2020
2021 /*
2022 * Remove the node from the device list and check
2023 * for whether or not we need to stop the nvme_thread.
2024 */
2025 static void nvme_dev_list_remove(struct nvme_dev *dev)
2026 {
2027         struct task_struct *tmp = NULL;
2028
2029         spin_lock(&dev_list_lock);
2030         list_del_init(&dev->node);
2031         if (list_empty(&dev_list) && !IS_ERR_OR_NULL(nvme_thread)) {
2032                 tmp = nvme_thread;
2033                 nvme_thread = NULL;
2034         }
2035         spin_unlock(&dev_list_lock);
2036
2037         if (tmp)
2038                 kthread_stop(tmp);
2039 }
2040
2041 static void nvme_freeze_queues(struct nvme_dev *dev)
2042 {
2043         struct nvme_ns *ns;
2044
2045         list_for_each_entry(ns, &dev->ctrl.namespaces, list) {
2046                 blk_mq_freeze_queue_start(ns->queue);
2047
2048                 spin_lock_irq(ns->queue->queue_lock);
2049                 queue_flag_set(QUEUE_FLAG_STOPPED, ns->queue);
2050                 spin_unlock_irq(ns->queue->queue_lock);
2051
2052                 blk_mq_cancel_requeue_work(ns->queue);
2053                 blk_mq_stop_hw_queues(ns->queue);
2054         }
2055 }
2056
2057 static void nvme_unfreeze_queues(struct nvme_dev *dev)
2058 {
2059         struct nvme_ns *ns;
2060
2061         list_for_each_entry(ns, &dev->ctrl.namespaces, list) {
2062                 queue_flag_clear_unlocked(QUEUE_FLAG_STOPPED, ns->queue);
2063                 blk_mq_unfreeze_queue(ns->queue);
2064                 blk_mq_start_stopped_hw_queues(ns->queue, true);
2065                 blk_mq_kick_requeue_list(ns->queue);
2066         }
2067 }
2068
2069 static void nvme_dev_shutdown(struct nvme_dev *dev)
2070 {
2071         int i;
2072         u32 csts = -1;
2073
2074         nvme_dev_list_remove(dev);
2075
2076         if (dev->bar) {
2077                 nvme_freeze_queues(dev);
2078                 csts = readl(dev->bar + NVME_REG_CSTS);
2079         }
2080         if (csts & NVME_CSTS_CFS || !(csts & NVME_CSTS_RDY)) {
2081                 for (i = dev->queue_count - 1; i >= 0; i--) {
2082                         struct nvme_queue *nvmeq = dev->queues[i];
2083                         nvme_suspend_queue(nvmeq);
2084                 }
2085         } else {
2086                 nvme_disable_io_queues(dev);
2087                 nvme_shutdown_ctrl(&dev->ctrl);
2088                 nvme_disable_queue(dev, 0);
2089         }
2090         nvme_dev_unmap(dev);
2091
2092         for (i = dev->queue_count - 1; i >= 0; i--)
2093                 nvme_clear_queue(dev->queues[i]);
2094 }
2095
2096 static int nvme_setup_prp_pools(struct nvme_dev *dev)
2097 {
2098         dev->prp_page_pool = dma_pool_create("prp list page", dev->dev,
2099                                                 PAGE_SIZE, PAGE_SIZE, 0);
2100         if (!dev->prp_page_pool)
2101                 return -ENOMEM;
2102
2103         /* Optimisation for I/Os between 4k and 128k */
2104         dev->prp_small_pool = dma_pool_create("prp list 256", dev->dev,
2105                                                 256, 256, 0);
2106         if (!dev->prp_small_pool) {
2107                 dma_pool_destroy(dev->prp_page_pool);
2108                 return -ENOMEM;
2109         }
2110         return 0;
2111 }
2112
2113 static void nvme_release_prp_pools(struct nvme_dev *dev)
2114 {
2115         dma_pool_destroy(dev->prp_page_pool);
2116         dma_pool_destroy(dev->prp_small_pool);
2117 }
2118
2119 static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
2120 {
2121         struct nvme_dev *dev = to_nvme_dev(ctrl);
2122
2123         put_device(dev->dev);
2124         if (dev->tagset.tags)
2125                 blk_mq_free_tag_set(&dev->tagset);
2126         if (dev->ctrl.admin_q)
2127                 blk_put_queue(dev->ctrl.admin_q);
2128         kfree(dev->queues);
2129         kfree(dev->entry);
2130         kfree(dev);
2131 }
2132
2133 static void nvme_probe_work(struct work_struct *work)
2134 {
2135         struct nvme_dev *dev = container_of(work, struct nvme_dev, probe_work);
2136         int result;
2137
2138         result = nvme_dev_map(dev);
2139         if (result)
2140                 goto out;
2141
2142         result = nvme_configure_admin_queue(dev);
2143         if (result)
2144                 goto unmap;
2145
2146         nvme_init_queue(dev->queues[0], 0);
2147         result = nvme_alloc_admin_tags(dev);
2148         if (result)
2149                 goto disable;
2150
2151         result = nvme_init_identify(&dev->ctrl);
2152         if (result)
2153                 goto free_tags;
2154
2155         result = nvme_setup_io_queues(dev);
2156         if (result)
2157                 goto free_tags;
2158
2159         dev->ctrl.event_limit = 1;
2160
2161         result = nvme_dev_list_add(dev);
2162         if (result)
2163                 goto remove;
2164
2165         /*
2166          * Keep the controller around but remove all namespaces if we don't have
2167          * any working I/O queue.
2168          */
2169         if (dev->online_queues < 2) {
2170                 dev_warn(dev->dev, "IO queues not created\n");
2171                 nvme_remove_namespaces(&dev->ctrl);
2172         } else {
2173                 nvme_unfreeze_queues(dev);
2174                 nvme_dev_add(dev);
2175         }
2176
2177         return;
2178
2179  remove:
2180         nvme_dev_list_remove(dev);
2181  free_tags:
2182         nvme_dev_remove_admin(dev);
2183         blk_put_queue(dev->ctrl.admin_q);
2184         dev->ctrl.admin_q = NULL;
2185         dev->queues[0]->tags = NULL;
2186  disable:
2187         nvme_disable_queue(dev, 0);
2188  unmap:
2189         nvme_dev_unmap(dev);
2190  out:
2191         if (!work_busy(&dev->reset_work))
2192                 nvme_dead_ctrl(dev);
2193 }
2194
2195 static int nvme_remove_dead_ctrl(void *arg)
2196 {
2197         struct nvme_dev *dev = (struct nvme_dev *)arg;
2198         struct pci_dev *pdev = to_pci_dev(dev->dev);
2199
2200         if (pci_get_drvdata(pdev))
2201                 pci_stop_and_remove_bus_device_locked(pdev);
2202         nvme_put_ctrl(&dev->ctrl);
2203         return 0;
2204 }
2205
2206 static void nvme_dead_ctrl(struct nvme_dev *dev)
2207 {
2208         dev_warn(dev->dev, "Device failed to resume\n");
2209         kref_get(&dev->ctrl.kref);
2210         if (IS_ERR(kthread_run(nvme_remove_dead_ctrl, dev, "nvme%d",
2211                                                 dev->ctrl.instance))) {
2212                 dev_err(dev->dev,
2213                         "Failed to start controller remove task\n");
2214                 nvme_put_ctrl(&dev->ctrl);
2215         }
2216 }
2217
2218 static void nvme_reset_work(struct work_struct *ws)
2219 {
2220         struct nvme_dev *dev = container_of(ws, struct nvme_dev, reset_work);
2221         bool in_probe = work_busy(&dev->probe_work);
2222
2223         nvme_dev_shutdown(dev);
2224
2225         /* Synchronize with device probe so that work will see failure status
2226          * and exit gracefully without trying to schedule another reset */
2227         flush_work(&dev->probe_work);
2228
2229         /* Fail this device if reset occured during probe to avoid
2230          * infinite initialization loops. */
2231         if (in_probe) {
2232                 nvme_dead_ctrl(dev);
2233                 return;
2234         }
2235         /* Schedule device resume asynchronously so the reset work is available
2236          * to cleanup errors that may occur during reinitialization */
2237         schedule_work(&dev->probe_work);
2238 }
2239
2240 static int __nvme_reset(struct nvme_dev *dev)
2241 {
2242         if (work_pending(&dev->reset_work))
2243                 return -EBUSY;
2244         list_del_init(&dev->node);
2245         queue_work(nvme_workq, &dev->reset_work);
2246         return 0;
2247 }
2248
2249 static int nvme_reset(struct nvme_dev *dev)
2250 {
2251         int ret;
2252
2253         if (!dev->ctrl.admin_q || blk_queue_dying(dev->ctrl.admin_q))
2254                 return -ENODEV;
2255
2256         spin_lock(&dev_list_lock);
2257         ret = __nvme_reset(dev);
2258         spin_unlock(&dev_list_lock);
2259
2260         if (!ret) {
2261                 flush_work(&dev->reset_work);
2262                 flush_work(&dev->probe_work);
2263                 return 0;
2264         }
2265
2266         return ret;
2267 }
2268
2269 static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
2270 {
2271         *val = readl(to_nvme_dev(ctrl)->bar + off);
2272         return 0;
2273 }
2274
2275 static int nvme_pci_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
2276 {
2277         writel(val, to_nvme_dev(ctrl)->bar + off);
2278         return 0;
2279 }
2280
2281 static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
2282 {
2283         *val = readq(to_nvme_dev(ctrl)->bar + off);
2284         return 0;
2285 }
2286
2287 static bool nvme_pci_io_incapable(struct nvme_ctrl *ctrl)
2288 {
2289         struct nvme_dev *dev = to_nvme_dev(ctrl);
2290
2291         return !dev->bar || dev->online_queues < 2;
2292 }
2293
2294 static int nvme_pci_reset_ctrl(struct nvme_ctrl *ctrl)
2295 {
2296         return nvme_reset(to_nvme_dev(ctrl));
2297 }
2298
2299 static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
2300         .reg_read32             = nvme_pci_reg_read32,
2301         .reg_write32            = nvme_pci_reg_write32,
2302         .reg_read64             = nvme_pci_reg_read64,
2303         .io_incapable           = nvme_pci_io_incapable,
2304         .reset_ctrl             = nvme_pci_reset_ctrl,
2305         .free_ctrl              = nvme_pci_free_ctrl,
2306 };
2307
2308 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
2309 {
2310         int node, result = -ENOMEM;
2311         struct nvme_dev *dev;
2312
2313         node = dev_to_node(&pdev->dev);
2314         if (node == NUMA_NO_NODE)
2315                 set_dev_node(&pdev->dev, 0);
2316
2317         dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
2318         if (!dev)
2319                 return -ENOMEM;
2320         dev->entry = kzalloc_node(num_possible_cpus() * sizeof(*dev->entry),
2321                                                         GFP_KERNEL, node);
2322         if (!dev->entry)
2323                 goto free;
2324         dev->queues = kzalloc_node((num_possible_cpus() + 1) * sizeof(void *),
2325                                                         GFP_KERNEL, node);
2326         if (!dev->queues)
2327                 goto free;
2328
2329         dev->dev = get_device(&pdev->dev);
2330         pci_set_drvdata(pdev, dev);
2331
2332         INIT_LIST_HEAD(&dev->node);
2333         INIT_WORK(&dev->scan_work, nvme_dev_scan);
2334         INIT_WORK(&dev->probe_work, nvme_probe_work);
2335         INIT_WORK(&dev->reset_work, nvme_reset_work);
2336
2337         result = nvme_setup_prp_pools(dev);
2338         if (result)
2339                 goto put_pci;
2340
2341         result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
2342                         id->driver_data);
2343         if (result)
2344                 goto release_pools;
2345
2346         schedule_work(&dev->probe_work);
2347         return 0;
2348
2349  release_pools:
2350         nvme_release_prp_pools(dev);
2351  put_pci:
2352         put_device(dev->dev);
2353  free:
2354         kfree(dev->queues);
2355         kfree(dev->entry);
2356         kfree(dev);
2357         return result;
2358 }
2359
2360 static void nvme_reset_notify(struct pci_dev *pdev, bool prepare)
2361 {
2362         struct nvme_dev *dev = pci_get_drvdata(pdev);
2363
2364         if (prepare)
2365                 nvme_dev_shutdown(dev);
2366         else
2367                 schedule_work(&dev->probe_work);
2368 }
2369
2370 static void nvme_shutdown(struct pci_dev *pdev)
2371 {
2372         struct nvme_dev *dev = pci_get_drvdata(pdev);
2373         nvme_dev_shutdown(dev);
2374 }
2375
2376 static void nvme_remove(struct pci_dev *pdev)
2377 {
2378         struct nvme_dev *dev = pci_get_drvdata(pdev);
2379
2380         spin_lock(&dev_list_lock);
2381         list_del_init(&dev->node);
2382         spin_unlock(&dev_list_lock);
2383
2384         pci_set_drvdata(pdev, NULL);
2385         flush_work(&dev->probe_work);
2386         flush_work(&dev->reset_work);
2387         flush_work(&dev->scan_work);
2388         nvme_remove_namespaces(&dev->ctrl);
2389         nvme_dev_shutdown(dev);
2390         nvme_dev_remove_admin(dev);
2391         nvme_free_queues(dev, 0);
2392         nvme_release_cmb(dev);
2393         nvme_release_prp_pools(dev);
2394         nvme_put_ctrl(&dev->ctrl);
2395 }
2396
2397 /* These functions are yet to be implemented */
2398 #define nvme_error_detected NULL
2399 #define nvme_dump_registers NULL
2400 #define nvme_link_reset NULL
2401 #define nvme_slot_reset NULL
2402 #define nvme_error_resume NULL
2403
2404 #ifdef CONFIG_PM_SLEEP
2405 static int nvme_suspend(struct device *dev)
2406 {
2407         struct pci_dev *pdev = to_pci_dev(dev);
2408         struct nvme_dev *ndev = pci_get_drvdata(pdev);
2409
2410         nvme_dev_shutdown(ndev);
2411         return 0;
2412 }
2413
2414 static int nvme_resume(struct device *dev)
2415 {
2416         struct pci_dev *pdev = to_pci_dev(dev);
2417         struct nvme_dev *ndev = pci_get_drvdata(pdev);
2418
2419         schedule_work(&ndev->probe_work);
2420         return 0;
2421 }
2422 #endif
2423
2424 static SIMPLE_DEV_PM_OPS(nvme_dev_pm_ops, nvme_suspend, nvme_resume);
2425
2426 static const struct pci_error_handlers nvme_err_handler = {
2427         .error_detected = nvme_error_detected,
2428         .mmio_enabled   = nvme_dump_registers,
2429         .link_reset     = nvme_link_reset,
2430         .slot_reset     = nvme_slot_reset,
2431         .resume         = nvme_error_resume,
2432         .reset_notify   = nvme_reset_notify,
2433 };
2434
2435 /* Move to pci_ids.h later */
2436 #define PCI_CLASS_STORAGE_EXPRESS       0x010802
2437
2438 static const struct pci_device_id nvme_id_table[] = {
2439         { PCI_VDEVICE(INTEL, 0x0953),
2440                 .driver_data = NVME_QUIRK_STRIPE_SIZE, },
2441         { PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
2442         { PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
2443         { 0, }
2444 };
2445 MODULE_DEVICE_TABLE(pci, nvme_id_table);
2446
2447 static struct pci_driver nvme_driver = {
2448         .name           = "nvme",
2449         .id_table       = nvme_id_table,
2450         .probe          = nvme_probe,
2451         .remove         = nvme_remove,
2452         .shutdown       = nvme_shutdown,
2453         .driver         = {
2454                 .pm     = &nvme_dev_pm_ops,
2455         },
2456         .err_handler    = &nvme_err_handler,
2457 };
2458
2459 static int __init nvme_init(void)
2460 {
2461         int result;
2462
2463         init_waitqueue_head(&nvme_kthread_wait);
2464
2465         nvme_workq = create_singlethread_workqueue("nvme");
2466         if (!nvme_workq)
2467                 return -ENOMEM;
2468
2469         result = nvme_core_init();
2470         if (result < 0)
2471                 goto kill_workq;
2472
2473         result = pci_register_driver(&nvme_driver);
2474         if (result)
2475                 goto core_exit;
2476         return 0;
2477
2478  core_exit:
2479         nvme_core_exit();
2480  kill_workq:
2481         destroy_workqueue(nvme_workq);
2482         return result;
2483 }
2484
2485 static void __exit nvme_exit(void)
2486 {
2487         pci_unregister_driver(&nvme_driver);
2488         nvme_core_exit();
2489         destroy_workqueue(nvme_workq);
2490         BUG_ON(nvme_thread && !IS_ERR(nvme_thread));
2491         _nvme_check_size();
2492 }
2493
2494 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
2495 MODULE_LICENSE("GPL");
2496 MODULE_VERSION("1.0");
2497 module_init(nvme_init);
2498 module_exit(nvme_exit);