xref: /linux/drivers/nvme/host/pci.c (revision 5e4e38446a62a4f50d77b0dd11d4b379dee08988)
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/aer.h>
16 #include <linux/bitops.h>
17 #include <linux/blkdev.h>
18 #include <linux/blk-mq.h>
19 #include <linux/cpu.h>
20 #include <linux/delay.h>
21 #include <linux/errno.h>
22 #include <linux/fs.h>
23 #include <linux/genhd.h>
24 #include <linux/hdreg.h>
25 #include <linux/idr.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/io.h>
29 #include <linux/kdev_t.h>
30 #include <linux/kthread.h>
31 #include <linux/kernel.h>
32 #include <linux/mm.h>
33 #include <linux/module.h>
34 #include <linux/moduleparam.h>
35 #include <linux/mutex.h>
36 #include <linux/pci.h>
37 #include <linux/poison.h>
38 #include <linux/ptrace.h>
39 #include <linux/sched.h>
40 #include <linux/slab.h>
41 #include <linux/t10-pi.h>
42 #include <linux/types.h>
43 #include <linux/io-64-nonatomic-lo-hi.h>
44 #include <asm/unaligned.h>
45 
46 #include "nvme.h"
47 
48 #define NVME_Q_DEPTH		1024
49 #define NVME_AQ_DEPTH		256
50 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
51 #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
52 
53 /*
54  * We handle AEN commands ourselves and don't even let the
55  * block layer know about them.
56  */
57 #define NVME_NR_AEN_COMMANDS	1
58 #define NVME_AQ_BLKMQ_DEPTH	(NVME_AQ_DEPTH - NVME_NR_AEN_COMMANDS)
59 
60 unsigned char admin_timeout = 60;
61 module_param(admin_timeout, byte, 0644);
62 MODULE_PARM_DESC(admin_timeout, "timeout in seconds for admin commands");
63 
64 unsigned char nvme_io_timeout = 30;
65 module_param_named(io_timeout, nvme_io_timeout, byte, 0644);
66 MODULE_PARM_DESC(io_timeout, "timeout in seconds for I/O");
67 
68 unsigned char shutdown_timeout = 5;
69 module_param(shutdown_timeout, byte, 0644);
70 MODULE_PARM_DESC(shutdown_timeout, "timeout in seconds for controller shutdown");
71 
72 static int use_threaded_interrupts;
73 module_param(use_threaded_interrupts, int, 0);
74 
75 static bool use_cmb_sqes = true;
76 module_param(use_cmb_sqes, bool, 0644);
77 MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes");
78 
79 static LIST_HEAD(dev_list);
80 static struct task_struct *nvme_thread;
81 static struct workqueue_struct *nvme_workq;
82 static wait_queue_head_t nvme_kthread_wait;
83 
84 struct nvme_dev;
85 struct nvme_queue;
86 
87 static int nvme_reset(struct nvme_dev *dev);
88 static void nvme_process_cq(struct nvme_queue *nvmeq);
89 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
90 
91 /*
92  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
93  */
94 struct nvme_dev {
95 	struct list_head node;
96 	struct nvme_queue **queues;
97 	struct blk_mq_tag_set tagset;
98 	struct blk_mq_tag_set admin_tagset;
99 	u32 __iomem *dbs;
100 	struct device *dev;
101 	struct dma_pool *prp_page_pool;
102 	struct dma_pool *prp_small_pool;
103 	unsigned queue_count;
104 	unsigned online_queues;
105 	unsigned max_qid;
106 	int q_depth;
107 	u32 db_stride;
108 	struct msix_entry *entry;
109 	void __iomem *bar;
110 	struct work_struct reset_work;
111 	struct work_struct scan_work;
112 	struct work_struct remove_work;
113 	struct mutex shutdown_lock;
114 	bool subsystem;
115 	void __iomem *cmb;
116 	dma_addr_t cmb_dma_addr;
117 	u64 cmb_size;
118 	u32 cmbsz;
119 	unsigned long flags;
120 
121 #define NVME_CTRL_RESETTING    0
122 #define NVME_CTRL_REMOVING     1
123 
124 	struct nvme_ctrl ctrl;
125 	struct completion ioq_wait;
126 };
127 
128 static inline struct nvme_dev *to_nvme_dev(struct nvme_ctrl *ctrl)
129 {
130 	return container_of(ctrl, struct nvme_dev, ctrl);
131 }
132 
133 /*
134  * An NVM Express queue.  Each device has at least two (one for admin
135  * commands and one for I/O commands).
136  */
137 struct nvme_queue {
138 	struct device *q_dmadev;
139 	struct nvme_dev *dev;
140 	char irqname[24];	/* nvme4294967295-65535\0 */
141 	spinlock_t q_lock;
142 	struct nvme_command *sq_cmds;
143 	struct nvme_command __iomem *sq_cmds_io;
144 	volatile struct nvme_completion *cqes;
145 	struct blk_mq_tags **tags;
146 	dma_addr_t sq_dma_addr;
147 	dma_addr_t cq_dma_addr;
148 	u32 __iomem *q_db;
149 	u16 q_depth;
150 	s16 cq_vector;
151 	u16 sq_head;
152 	u16 sq_tail;
153 	u16 cq_head;
154 	u16 qid;
155 	u8 cq_phase;
156 	u8 cqe_seen;
157 };
158 
159 /*
160  * The nvme_iod describes the data in an I/O, including the list of PRP
161  * entries.  You can't see it in this data structure because C doesn't let
162  * me express that.  Use nvme_init_iod to ensure there's enough space
163  * allocated to store the PRP list.
164  */
165 struct nvme_iod {
166 	struct nvme_queue *nvmeq;
167 	int aborted;
168 	int npages;		/* In the PRP list. 0 means small pool in use */
169 	int nents;		/* Used in scatterlist */
170 	int length;		/* Of data, in bytes */
171 	dma_addr_t first_dma;
172 	struct scatterlist meta_sg; /* metadata requires single contiguous buffer */
173 	struct scatterlist *sg;
174 	struct scatterlist inline_sg[0];
175 };
176 
177 /*
178  * Check we didin't inadvertently grow the command struct
179  */
180 static inline void _nvme_check_size(void)
181 {
182 	BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
183 	BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
184 	BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
185 	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
186 	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
187 	BUILD_BUG_ON(sizeof(struct nvme_format_cmd) != 64);
188 	BUILD_BUG_ON(sizeof(struct nvme_abort_cmd) != 64);
189 	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
190 	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != 4096);
191 	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != 4096);
192 	BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
193 	BUILD_BUG_ON(sizeof(struct nvme_smart_log) != 512);
194 }
195 
196 /*
197  * Max size of iod being embedded in the request payload
198  */
199 #define NVME_INT_PAGES		2
200 #define NVME_INT_BYTES(dev)	(NVME_INT_PAGES * (dev)->ctrl.page_size)
201 
202 /*
203  * Will slightly overestimate the number of pages needed.  This is OK
204  * as it only leads to a small amount of wasted memory for the lifetime of
205  * the I/O.
206  */
207 static int nvme_npages(unsigned size, struct nvme_dev *dev)
208 {
209 	unsigned nprps = DIV_ROUND_UP(size + dev->ctrl.page_size,
210 				      dev->ctrl.page_size);
211 	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
212 }
213 
214 static unsigned int nvme_iod_alloc_size(struct nvme_dev *dev,
215 		unsigned int size, unsigned int nseg)
216 {
217 	return sizeof(__le64 *) * nvme_npages(size, dev) +
218 			sizeof(struct scatterlist) * nseg;
219 }
220 
221 static unsigned int nvme_cmd_size(struct nvme_dev *dev)
222 {
223 	return sizeof(struct nvme_iod) +
224 		nvme_iod_alloc_size(dev, NVME_INT_BYTES(dev), NVME_INT_PAGES);
225 }
226 
227 static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
228 				unsigned int hctx_idx)
229 {
230 	struct nvme_dev *dev = data;
231 	struct nvme_queue *nvmeq = dev->queues[0];
232 
233 	WARN_ON(hctx_idx != 0);
234 	WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);
235 	WARN_ON(nvmeq->tags);
236 
237 	hctx->driver_data = nvmeq;
238 	nvmeq->tags = &dev->admin_tagset.tags[0];
239 	return 0;
240 }
241 
242 static void nvme_admin_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
243 {
244 	struct nvme_queue *nvmeq = hctx->driver_data;
245 
246 	nvmeq->tags = NULL;
247 }
248 
249 static int nvme_admin_init_request(void *data, struct request *req,
250 				unsigned int hctx_idx, unsigned int rq_idx,
251 				unsigned int numa_node)
252 {
253 	struct nvme_dev *dev = data;
254 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
255 	struct nvme_queue *nvmeq = dev->queues[0];
256 
257 	BUG_ON(!nvmeq);
258 	iod->nvmeq = nvmeq;
259 	return 0;
260 }
261 
262 static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
263 			  unsigned int hctx_idx)
264 {
265 	struct nvme_dev *dev = data;
266 	struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
267 
268 	if (!nvmeq->tags)
269 		nvmeq->tags = &dev->tagset.tags[hctx_idx];
270 
271 	WARN_ON(dev->tagset.tags[hctx_idx] != hctx->tags);
272 	hctx->driver_data = nvmeq;
273 	return 0;
274 }
275 
276 static int nvme_init_request(void *data, struct request *req,
277 				unsigned int hctx_idx, unsigned int rq_idx,
278 				unsigned int numa_node)
279 {
280 	struct nvme_dev *dev = data;
281 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
282 	struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
283 
284 	BUG_ON(!nvmeq);
285 	iod->nvmeq = nvmeq;
286 	return 0;
287 }
288 
289 static void nvme_queue_scan(struct nvme_dev *dev)
290 {
291 	/*
292 	 * Do not queue new scan work when a controller is reset during
293 	 * removal.
294 	 */
295 	if (test_bit(NVME_CTRL_REMOVING, &dev->flags))
296 		return;
297 	queue_work(nvme_workq, &dev->scan_work);
298 }
299 
300 static void nvme_complete_async_event(struct nvme_dev *dev,
301 		struct nvme_completion *cqe)
302 {
303 	u16 status = le16_to_cpu(cqe->status) >> 1;
304 	u32 result = le32_to_cpu(cqe->result);
305 
306 	if (status == NVME_SC_SUCCESS || status == NVME_SC_ABORT_REQ)
307 		++dev->ctrl.event_limit;
308 	if (status != NVME_SC_SUCCESS)
309 		return;
310 
311 	switch (result & 0xff07) {
312 	case NVME_AER_NOTICE_NS_CHANGED:
313 		dev_info(dev->dev, "rescanning\n");
314 		nvme_queue_scan(dev);
315 	default:
316 		dev_warn(dev->dev, "async event result %08x\n", result);
317 	}
318 }
319 
320 /**
321  * __nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
322  * @nvmeq: The queue to use
323  * @cmd: The command to send
324  *
325  * Safe to use from interrupt context
326  */
327 static void __nvme_submit_cmd(struct nvme_queue *nvmeq,
328 						struct nvme_command *cmd)
329 {
330 	u16 tail = nvmeq->sq_tail;
331 
332 	if (nvmeq->sq_cmds_io)
333 		memcpy_toio(&nvmeq->sq_cmds_io[tail], cmd, sizeof(*cmd));
334 	else
335 		memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
336 
337 	if (++tail == nvmeq->q_depth)
338 		tail = 0;
339 	writel(tail, nvmeq->q_db);
340 	nvmeq->sq_tail = tail;
341 }
342 
343 static __le64 **iod_list(struct request *req)
344 {
345 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
346 	return (__le64 **)(iod->sg + req->nr_phys_segments);
347 }
348 
349 static int nvme_init_iod(struct request *rq, struct nvme_dev *dev)
350 {
351 	struct nvme_iod *iod = blk_mq_rq_to_pdu(rq);
352 	int nseg = rq->nr_phys_segments;
353 	unsigned size;
354 
355 	if (rq->cmd_flags & REQ_DISCARD)
356 		size = sizeof(struct nvme_dsm_range);
357 	else
358 		size = blk_rq_bytes(rq);
359 
360 	if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
361 		iod->sg = kmalloc(nvme_iod_alloc_size(dev, size, nseg), GFP_ATOMIC);
362 		if (!iod->sg)
363 			return BLK_MQ_RQ_QUEUE_BUSY;
364 	} else {
365 		iod->sg = iod->inline_sg;
366 	}
367 
368 	iod->aborted = 0;
369 	iod->npages = -1;
370 	iod->nents = 0;
371 	iod->length = size;
372 	return 0;
373 }
374 
375 static void nvme_free_iod(struct nvme_dev *dev, struct request *req)
376 {
377 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
378 	const int last_prp = dev->ctrl.page_size / 8 - 1;
379 	int i;
380 	__le64 **list = iod_list(req);
381 	dma_addr_t prp_dma = iod->first_dma;
382 
383 	if (iod->npages == 0)
384 		dma_pool_free(dev->prp_small_pool, list[0], prp_dma);
385 	for (i = 0; i < iod->npages; i++) {
386 		__le64 *prp_list = list[i];
387 		dma_addr_t next_prp_dma = le64_to_cpu(prp_list[last_prp]);
388 		dma_pool_free(dev->prp_page_pool, prp_list, prp_dma);
389 		prp_dma = next_prp_dma;
390 	}
391 
392 	if (iod->sg != iod->inline_sg)
393 		kfree(iod->sg);
394 }
395 
396 #ifdef CONFIG_BLK_DEV_INTEGRITY
397 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
398 {
399 	if (be32_to_cpu(pi->ref_tag) == v)
400 		pi->ref_tag = cpu_to_be32(p);
401 }
402 
403 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
404 {
405 	if (be32_to_cpu(pi->ref_tag) == p)
406 		pi->ref_tag = cpu_to_be32(v);
407 }
408 
409 /**
410  * nvme_dif_remap - remaps ref tags to bip seed and physical lba
411  *
412  * The virtual start sector is the one that was originally submitted by the
413  * block layer.	Due to partitioning, MD/DM cloning, etc. the actual physical
414  * start sector may be different. Remap protection information to match the
415  * physical LBA on writes, and back to the original seed on reads.
416  *
417  * Type 0 and 3 do not have a ref tag, so no remapping required.
418  */
419 static void nvme_dif_remap(struct request *req,
420 			void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
421 {
422 	struct nvme_ns *ns = req->rq_disk->private_data;
423 	struct bio_integrity_payload *bip;
424 	struct t10_pi_tuple *pi;
425 	void *p, *pmap;
426 	u32 i, nlb, ts, phys, virt;
427 
428 	if (!ns->pi_type || ns->pi_type == NVME_NS_DPS_PI_TYPE3)
429 		return;
430 
431 	bip = bio_integrity(req->bio);
432 	if (!bip)
433 		return;
434 
435 	pmap = kmap_atomic(bip->bip_vec->bv_page) + bip->bip_vec->bv_offset;
436 
437 	p = pmap;
438 	virt = bip_get_seed(bip);
439 	phys = nvme_block_nr(ns, blk_rq_pos(req));
440 	nlb = (blk_rq_bytes(req) >> ns->lba_shift);
441 	ts = ns->disk->queue->integrity.tuple_size;
442 
443 	for (i = 0; i < nlb; i++, virt++, phys++) {
444 		pi = (struct t10_pi_tuple *)p;
445 		dif_swap(phys, virt, pi);
446 		p += ts;
447 	}
448 	kunmap_atomic(pmap);
449 }
450 #else /* CONFIG_BLK_DEV_INTEGRITY */
451 static void nvme_dif_remap(struct request *req,
452 			void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
453 {
454 }
455 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
456 {
457 }
458 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
459 {
460 }
461 #endif
462 
463 static bool nvme_setup_prps(struct nvme_dev *dev, struct request *req,
464 		int total_len)
465 {
466 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
467 	struct dma_pool *pool;
468 	int length = total_len;
469 	struct scatterlist *sg = iod->sg;
470 	int dma_len = sg_dma_len(sg);
471 	u64 dma_addr = sg_dma_address(sg);
472 	u32 page_size = dev->ctrl.page_size;
473 	int offset = dma_addr & (page_size - 1);
474 	__le64 *prp_list;
475 	__le64 **list = iod_list(req);
476 	dma_addr_t prp_dma;
477 	int nprps, i;
478 
479 	length -= (page_size - offset);
480 	if (length <= 0)
481 		return true;
482 
483 	dma_len -= (page_size - offset);
484 	if (dma_len) {
485 		dma_addr += (page_size - offset);
486 	} else {
487 		sg = sg_next(sg);
488 		dma_addr = sg_dma_address(sg);
489 		dma_len = sg_dma_len(sg);
490 	}
491 
492 	if (length <= page_size) {
493 		iod->first_dma = dma_addr;
494 		return true;
495 	}
496 
497 	nprps = DIV_ROUND_UP(length, page_size);
498 	if (nprps <= (256 / 8)) {
499 		pool = dev->prp_small_pool;
500 		iod->npages = 0;
501 	} else {
502 		pool = dev->prp_page_pool;
503 		iod->npages = 1;
504 	}
505 
506 	prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
507 	if (!prp_list) {
508 		iod->first_dma = dma_addr;
509 		iod->npages = -1;
510 		return false;
511 	}
512 	list[0] = prp_list;
513 	iod->first_dma = prp_dma;
514 	i = 0;
515 	for (;;) {
516 		if (i == page_size >> 3) {
517 			__le64 *old_prp_list = prp_list;
518 			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
519 			if (!prp_list)
520 				return false;
521 			list[iod->npages++] = prp_list;
522 			prp_list[0] = old_prp_list[i - 1];
523 			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
524 			i = 1;
525 		}
526 		prp_list[i++] = cpu_to_le64(dma_addr);
527 		dma_len -= page_size;
528 		dma_addr += page_size;
529 		length -= page_size;
530 		if (length <= 0)
531 			break;
532 		if (dma_len > 0)
533 			continue;
534 		BUG_ON(dma_len < 0);
535 		sg = sg_next(sg);
536 		dma_addr = sg_dma_address(sg);
537 		dma_len = sg_dma_len(sg);
538 	}
539 
540 	return true;
541 }
542 
543 static int nvme_map_data(struct nvme_dev *dev, struct request *req,
544 		struct nvme_command *cmnd)
545 {
546 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
547 	struct request_queue *q = req->q;
548 	enum dma_data_direction dma_dir = rq_data_dir(req) ?
549 			DMA_TO_DEVICE : DMA_FROM_DEVICE;
550 	int ret = BLK_MQ_RQ_QUEUE_ERROR;
551 
552 	sg_init_table(iod->sg, req->nr_phys_segments);
553 	iod->nents = blk_rq_map_sg(q, req, iod->sg);
554 	if (!iod->nents)
555 		goto out;
556 
557 	ret = BLK_MQ_RQ_QUEUE_BUSY;
558 	if (!dma_map_sg(dev->dev, iod->sg, iod->nents, dma_dir))
559 		goto out;
560 
561 	if (!nvme_setup_prps(dev, req, blk_rq_bytes(req)))
562 		goto out_unmap;
563 
564 	ret = BLK_MQ_RQ_QUEUE_ERROR;
565 	if (blk_integrity_rq(req)) {
566 		if (blk_rq_count_integrity_sg(q, req->bio) != 1)
567 			goto out_unmap;
568 
569 		sg_init_table(&iod->meta_sg, 1);
570 		if (blk_rq_map_integrity_sg(q, req->bio, &iod->meta_sg) != 1)
571 			goto out_unmap;
572 
573 		if (rq_data_dir(req))
574 			nvme_dif_remap(req, nvme_dif_prep);
575 
576 		if (!dma_map_sg(dev->dev, &iod->meta_sg, 1, dma_dir))
577 			goto out_unmap;
578 	}
579 
580 	cmnd->rw.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
581 	cmnd->rw.prp2 = cpu_to_le64(iod->first_dma);
582 	if (blk_integrity_rq(req))
583 		cmnd->rw.metadata = cpu_to_le64(sg_dma_address(&iod->meta_sg));
584 	return BLK_MQ_RQ_QUEUE_OK;
585 
586 out_unmap:
587 	dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
588 out:
589 	return ret;
590 }
591 
592 static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
593 {
594 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
595 	enum dma_data_direction dma_dir = rq_data_dir(req) ?
596 			DMA_TO_DEVICE : DMA_FROM_DEVICE;
597 
598 	if (iod->nents) {
599 		dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
600 		if (blk_integrity_rq(req)) {
601 			if (!rq_data_dir(req))
602 				nvme_dif_remap(req, nvme_dif_complete);
603 			dma_unmap_sg(dev->dev, &iod->meta_sg, 1, dma_dir);
604 		}
605 	}
606 
607 	nvme_free_iod(dev, req);
608 }
609 
610 /*
611  * We reuse the small pool to allocate the 16-byte range here as it is not
612  * worth having a special pool for these or additional cases to handle freeing
613  * the iod.
614  */
615 static int nvme_setup_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns,
616 		struct request *req, struct nvme_command *cmnd)
617 {
618 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
619 	struct nvme_dsm_range *range;
620 
621 	range = dma_pool_alloc(nvmeq->dev->prp_small_pool, GFP_ATOMIC,
622 						&iod->first_dma);
623 	if (!range)
624 		return BLK_MQ_RQ_QUEUE_BUSY;
625 	iod_list(req)[0] = (__le64 *)range;
626 	iod->npages = 0;
627 
628 	range->cattr = cpu_to_le32(0);
629 	range->nlb = cpu_to_le32(blk_rq_bytes(req) >> ns->lba_shift);
630 	range->slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));
631 
632 	memset(cmnd, 0, sizeof(*cmnd));
633 	cmnd->dsm.opcode = nvme_cmd_dsm;
634 	cmnd->dsm.nsid = cpu_to_le32(ns->ns_id);
635 	cmnd->dsm.prp1 = cpu_to_le64(iod->first_dma);
636 	cmnd->dsm.nr = 0;
637 	cmnd->dsm.attributes = cpu_to_le32(NVME_DSMGMT_AD);
638 	return BLK_MQ_RQ_QUEUE_OK;
639 }
640 
641 /*
642  * NOTE: ns is NULL when called on the admin queue.
643  */
644 static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
645 			 const struct blk_mq_queue_data *bd)
646 {
647 	struct nvme_ns *ns = hctx->queue->queuedata;
648 	struct nvme_queue *nvmeq = hctx->driver_data;
649 	struct nvme_dev *dev = nvmeq->dev;
650 	struct request *req = bd->rq;
651 	struct nvme_command cmnd;
652 	int ret = BLK_MQ_RQ_QUEUE_OK;
653 
654 	/*
655 	 * If formated with metadata, require the block layer provide a buffer
656 	 * unless this namespace is formated such that the metadata can be
657 	 * stripped/generated by the controller with PRACT=1.
658 	 */
659 	if (ns && ns->ms && !blk_integrity_rq(req)) {
660 		if (!(ns->pi_type && ns->ms == 8) &&
661 					req->cmd_type != REQ_TYPE_DRV_PRIV) {
662 			blk_mq_end_request(req, -EFAULT);
663 			return BLK_MQ_RQ_QUEUE_OK;
664 		}
665 	}
666 
667 	ret = nvme_init_iod(req, dev);
668 	if (ret)
669 		return ret;
670 
671 	if (req->cmd_flags & REQ_DISCARD) {
672 		ret = nvme_setup_discard(nvmeq, ns, req, &cmnd);
673 	} else {
674 		if (req->cmd_type == REQ_TYPE_DRV_PRIV)
675 			memcpy(&cmnd, req->cmd, sizeof(cmnd));
676 		else if (req->cmd_flags & REQ_FLUSH)
677 			nvme_setup_flush(ns, &cmnd);
678 		else
679 			nvme_setup_rw(ns, req, &cmnd);
680 
681 		if (req->nr_phys_segments)
682 			ret = nvme_map_data(dev, req, &cmnd);
683 	}
684 
685 	if (ret)
686 		goto out;
687 
688 	cmnd.common.command_id = req->tag;
689 	blk_mq_start_request(req);
690 
691 	spin_lock_irq(&nvmeq->q_lock);
692 	if (unlikely(nvmeq->cq_vector < 0)) {
693 		if (ns && !test_bit(NVME_NS_DEAD, &ns->flags))
694 			ret = BLK_MQ_RQ_QUEUE_BUSY;
695 		else
696 			ret = BLK_MQ_RQ_QUEUE_ERROR;
697 		spin_unlock_irq(&nvmeq->q_lock);
698 		goto out;
699 	}
700 	__nvme_submit_cmd(nvmeq, &cmnd);
701 	nvme_process_cq(nvmeq);
702 	spin_unlock_irq(&nvmeq->q_lock);
703 	return BLK_MQ_RQ_QUEUE_OK;
704 out:
705 	nvme_free_iod(dev, req);
706 	return ret;
707 }
708 
709 static void nvme_complete_rq(struct request *req)
710 {
711 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
712 	struct nvme_dev *dev = iod->nvmeq->dev;
713 	int error = 0;
714 
715 	nvme_unmap_data(dev, req);
716 
717 	if (unlikely(req->errors)) {
718 		if (nvme_req_needs_retry(req, req->errors)) {
719 			nvme_requeue_req(req);
720 			return;
721 		}
722 
723 		if (req->cmd_type == REQ_TYPE_DRV_PRIV)
724 			error = req->errors;
725 		else
726 			error = nvme_error_status(req->errors);
727 	}
728 
729 	if (unlikely(iod->aborted)) {
730 		dev_warn(dev->dev,
731 			"completing aborted command with status: %04x\n",
732 			req->errors);
733 	}
734 
735 	blk_mq_end_request(req, error);
736 }
737 
738 static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
739 {
740 	u16 head, phase;
741 
742 	head = nvmeq->cq_head;
743 	phase = nvmeq->cq_phase;
744 
745 	for (;;) {
746 		struct nvme_completion cqe = nvmeq->cqes[head];
747 		u16 status = le16_to_cpu(cqe.status);
748 		struct request *req;
749 
750 		if ((status & 1) != phase)
751 			break;
752 		nvmeq->sq_head = le16_to_cpu(cqe.sq_head);
753 		if (++head == nvmeq->q_depth) {
754 			head = 0;
755 			phase = !phase;
756 		}
757 
758 		if (tag && *tag == cqe.command_id)
759 			*tag = -1;
760 
761 		if (unlikely(cqe.command_id >= nvmeq->q_depth)) {
762 			dev_warn(nvmeq->q_dmadev,
763 				"invalid id %d completed on queue %d\n",
764 				cqe.command_id, le16_to_cpu(cqe.sq_id));
765 			continue;
766 		}
767 
768 		/*
769 		 * AEN requests are special as they don't time out and can
770 		 * survive any kind of queue freeze and often don't respond to
771 		 * aborts.  We don't even bother to allocate a struct request
772 		 * for them but rather special case them here.
773 		 */
774 		if (unlikely(nvmeq->qid == 0 &&
775 				cqe.command_id >= NVME_AQ_BLKMQ_DEPTH)) {
776 			nvme_complete_async_event(nvmeq->dev, &cqe);
777 			continue;
778 		}
779 
780 		req = blk_mq_tag_to_rq(*nvmeq->tags, cqe.command_id);
781 		if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
782 			u32 result = le32_to_cpu(cqe.result);
783 			req->special = (void *)(uintptr_t)result;
784 		}
785 		blk_mq_complete_request(req, status >> 1);
786 
787 	}
788 
789 	/* If the controller ignores the cq head doorbell and continuously
790 	 * writes to the queue, it is theoretically possible to wrap around
791 	 * the queue twice and mistakenly return IRQ_NONE.  Linux only
792 	 * requires that 0.1% of your interrupts are handled, so this isn't
793 	 * a big problem.
794 	 */
795 	if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
796 		return;
797 
798 	if (likely(nvmeq->cq_vector >= 0))
799 		writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
800 	nvmeq->cq_head = head;
801 	nvmeq->cq_phase = phase;
802 
803 	nvmeq->cqe_seen = 1;
804 }
805 
806 static void nvme_process_cq(struct nvme_queue *nvmeq)
807 {
808 	__nvme_process_cq(nvmeq, NULL);
809 }
810 
811 static irqreturn_t nvme_irq(int irq, void *data)
812 {
813 	irqreturn_t result;
814 	struct nvme_queue *nvmeq = data;
815 	spin_lock(&nvmeq->q_lock);
816 	nvme_process_cq(nvmeq);
817 	result = nvmeq->cqe_seen ? IRQ_HANDLED : IRQ_NONE;
818 	nvmeq->cqe_seen = 0;
819 	spin_unlock(&nvmeq->q_lock);
820 	return result;
821 }
822 
823 static irqreturn_t nvme_irq_check(int irq, void *data)
824 {
825 	struct nvme_queue *nvmeq = data;
826 	struct nvme_completion cqe = nvmeq->cqes[nvmeq->cq_head];
827 	if ((le16_to_cpu(cqe.status) & 1) != nvmeq->cq_phase)
828 		return IRQ_NONE;
829 	return IRQ_WAKE_THREAD;
830 }
831 
832 static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
833 {
834 	struct nvme_queue *nvmeq = hctx->driver_data;
835 
836 	if ((le16_to_cpu(nvmeq->cqes[nvmeq->cq_head].status) & 1) ==
837 	    nvmeq->cq_phase) {
838 		spin_lock_irq(&nvmeq->q_lock);
839 		__nvme_process_cq(nvmeq, &tag);
840 		spin_unlock_irq(&nvmeq->q_lock);
841 
842 		if (tag == -1)
843 			return 1;
844 	}
845 
846 	return 0;
847 }
848 
849 static void nvme_submit_async_event(struct nvme_dev *dev)
850 {
851 	struct nvme_command c;
852 
853 	memset(&c, 0, sizeof(c));
854 	c.common.opcode = nvme_admin_async_event;
855 	c.common.command_id = NVME_AQ_BLKMQ_DEPTH + --dev->ctrl.event_limit;
856 
857 	__nvme_submit_cmd(dev->queues[0], &c);
858 }
859 
860 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
861 {
862 	struct nvme_command c;
863 
864 	memset(&c, 0, sizeof(c));
865 	c.delete_queue.opcode = opcode;
866 	c.delete_queue.qid = cpu_to_le16(id);
867 
868 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
869 }
870 
871 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
872 						struct nvme_queue *nvmeq)
873 {
874 	struct nvme_command c;
875 	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
876 
877 	/*
878 	 * Note: we (ab)use the fact the the prp fields survive if no data
879 	 * is attached to the request.
880 	 */
881 	memset(&c, 0, sizeof(c));
882 	c.create_cq.opcode = nvme_admin_create_cq;
883 	c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
884 	c.create_cq.cqid = cpu_to_le16(qid);
885 	c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
886 	c.create_cq.cq_flags = cpu_to_le16(flags);
887 	c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
888 
889 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
890 }
891 
892 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
893 						struct nvme_queue *nvmeq)
894 {
895 	struct nvme_command c;
896 	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_SQ_PRIO_MEDIUM;
897 
898 	/*
899 	 * Note: we (ab)use the fact the the prp fields survive if no data
900 	 * is attached to the request.
901 	 */
902 	memset(&c, 0, sizeof(c));
903 	c.create_sq.opcode = nvme_admin_create_sq;
904 	c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
905 	c.create_sq.sqid = cpu_to_le16(qid);
906 	c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
907 	c.create_sq.sq_flags = cpu_to_le16(flags);
908 	c.create_sq.cqid = cpu_to_le16(qid);
909 
910 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
911 }
912 
913 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
914 {
915 	return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
916 }
917 
918 static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
919 {
920 	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
921 }
922 
923 static void abort_endio(struct request *req, int error)
924 {
925 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
926 	struct nvme_queue *nvmeq = iod->nvmeq;
927 	u32 result = (u32)(uintptr_t)req->special;
928 	u16 status = req->errors;
929 
930 	dev_warn(nvmeq->q_dmadev, "Abort status:%x result:%x", status, result);
931 	atomic_inc(&nvmeq->dev->ctrl.abort_limit);
932 
933 	blk_mq_free_request(req);
934 }
935 
936 static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
937 {
938 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
939 	struct nvme_queue *nvmeq = iod->nvmeq;
940 	struct nvme_dev *dev = nvmeq->dev;
941 	struct request *abort_req;
942 	struct nvme_command cmd;
943 
944 	/*
945 	 * Shutdown immediately if controller times out while starting. The
946 	 * reset work will see the pci device disabled when it gets the forced
947 	 * cancellation error. All outstanding requests are completed on
948 	 * shutdown, so we return BLK_EH_HANDLED.
949 	 */
950 	if (test_bit(NVME_CTRL_RESETTING, &dev->flags)) {
951 		dev_warn(dev->dev,
952 			 "I/O %d QID %d timeout, disable controller\n",
953 			 req->tag, nvmeq->qid);
954 		nvme_dev_disable(dev, false);
955 		req->errors = NVME_SC_CANCELLED;
956 		return BLK_EH_HANDLED;
957 	}
958 
959 	/*
960  	 * Shutdown the controller immediately and schedule a reset if the
961  	 * command was already aborted once before and still hasn't been
962  	 * returned to the driver, or if this is the admin queue.
963 	 */
964 	if (!nvmeq->qid || iod->aborted) {
965 		dev_warn(dev->dev,
966 			 "I/O %d QID %d timeout, reset controller\n",
967 			 req->tag, nvmeq->qid);
968 		nvme_dev_disable(dev, false);
969 		queue_work(nvme_workq, &dev->reset_work);
970 
971 		/*
972 		 * Mark the request as handled, since the inline shutdown
973 		 * forces all outstanding requests to complete.
974 		 */
975 		req->errors = NVME_SC_CANCELLED;
976 		return BLK_EH_HANDLED;
977 	}
978 
979 	iod->aborted = 1;
980 
981 	if (atomic_dec_return(&dev->ctrl.abort_limit) < 0) {
982 		atomic_inc(&dev->ctrl.abort_limit);
983 		return BLK_EH_RESET_TIMER;
984 	}
985 
986 	memset(&cmd, 0, sizeof(cmd));
987 	cmd.abort.opcode = nvme_admin_abort_cmd;
988 	cmd.abort.cid = req->tag;
989 	cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
990 
991 	dev_warn(nvmeq->q_dmadev, "I/O %d QID %d timeout, aborting\n",
992 				 req->tag, nvmeq->qid);
993 
994 	abort_req = nvme_alloc_request(dev->ctrl.admin_q, &cmd,
995 			BLK_MQ_REQ_NOWAIT);
996 	if (IS_ERR(abort_req)) {
997 		atomic_inc(&dev->ctrl.abort_limit);
998 		return BLK_EH_RESET_TIMER;
999 	}
1000 
1001 	abort_req->timeout = ADMIN_TIMEOUT;
1002 	abort_req->end_io_data = NULL;
1003 	blk_execute_rq_nowait(abort_req->q, NULL, abort_req, 0, abort_endio);
1004 
1005 	/*
1006 	 * The aborted req will be completed on receiving the abort req.
1007 	 * We enable the timer again. If hit twice, it'll cause a device reset,
1008 	 * as the device then is in a faulty state.
1009 	 */
1010 	return BLK_EH_RESET_TIMER;
1011 }
1012 
1013 static void nvme_cancel_queue_ios(struct request *req, void *data, bool reserved)
1014 {
1015 	struct nvme_queue *nvmeq = data;
1016 	int status;
1017 
1018 	if (!blk_mq_request_started(req))
1019 		return;
1020 
1021 	dev_dbg_ratelimited(nvmeq->q_dmadev,
1022 		 "Cancelling I/O %d QID %d\n", req->tag, nvmeq->qid);
1023 
1024 	status = NVME_SC_ABORT_REQ;
1025 	if (blk_queue_dying(req->q))
1026 		status |= NVME_SC_DNR;
1027 	blk_mq_complete_request(req, status);
1028 }
1029 
1030 static void nvme_free_queue(struct nvme_queue *nvmeq)
1031 {
1032 	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
1033 				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
1034 	if (nvmeq->sq_cmds)
1035 		dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
1036 					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
1037 	kfree(nvmeq);
1038 }
1039 
1040 static void nvme_free_queues(struct nvme_dev *dev, int lowest)
1041 {
1042 	int i;
1043 
1044 	for (i = dev->queue_count - 1; i >= lowest; i--) {
1045 		struct nvme_queue *nvmeq = dev->queues[i];
1046 		dev->queue_count--;
1047 		dev->queues[i] = NULL;
1048 		nvme_free_queue(nvmeq);
1049 	}
1050 }
1051 
1052 /**
1053  * nvme_suspend_queue - put queue into suspended state
1054  * @nvmeq - queue to suspend
1055  */
1056 static int nvme_suspend_queue(struct nvme_queue *nvmeq)
1057 {
1058 	int vector;
1059 
1060 	spin_lock_irq(&nvmeq->q_lock);
1061 	if (nvmeq->cq_vector == -1) {
1062 		spin_unlock_irq(&nvmeq->q_lock);
1063 		return 1;
1064 	}
1065 	vector = nvmeq->dev->entry[nvmeq->cq_vector].vector;
1066 	nvmeq->dev->online_queues--;
1067 	nvmeq->cq_vector = -1;
1068 	spin_unlock_irq(&nvmeq->q_lock);
1069 
1070 	if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
1071 		blk_mq_stop_hw_queues(nvmeq->dev->ctrl.admin_q);
1072 
1073 	irq_set_affinity_hint(vector, NULL);
1074 	free_irq(vector, nvmeq);
1075 
1076 	return 0;
1077 }
1078 
1079 static void nvme_clear_queue(struct nvme_queue *nvmeq)
1080 {
1081 	spin_lock_irq(&nvmeq->q_lock);
1082 	if (nvmeq->tags && *nvmeq->tags)
1083 		blk_mq_all_tag_busy_iter(*nvmeq->tags, nvme_cancel_queue_ios, nvmeq);
1084 	spin_unlock_irq(&nvmeq->q_lock);
1085 }
1086 
1087 static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
1088 {
1089 	struct nvme_queue *nvmeq = dev->queues[0];
1090 
1091 	if (!nvmeq)
1092 		return;
1093 	if (nvme_suspend_queue(nvmeq))
1094 		return;
1095 
1096 	if (shutdown)
1097 		nvme_shutdown_ctrl(&dev->ctrl);
1098 	else
1099 		nvme_disable_ctrl(&dev->ctrl, lo_hi_readq(
1100 						dev->bar + NVME_REG_CAP));
1101 
1102 	spin_lock_irq(&nvmeq->q_lock);
1103 	nvme_process_cq(nvmeq);
1104 	spin_unlock_irq(&nvmeq->q_lock);
1105 }
1106 
1107 static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues,
1108 				int entry_size)
1109 {
1110 	int q_depth = dev->q_depth;
1111 	unsigned q_size_aligned = roundup(q_depth * entry_size,
1112 					  dev->ctrl.page_size);
1113 
1114 	if (q_size_aligned * nr_io_queues > dev->cmb_size) {
1115 		u64 mem_per_q = div_u64(dev->cmb_size, nr_io_queues);
1116 		mem_per_q = round_down(mem_per_q, dev->ctrl.page_size);
1117 		q_depth = div_u64(mem_per_q, entry_size);
1118 
1119 		/*
1120 		 * Ensure the reduced q_depth is above some threshold where it
1121 		 * would be better to map queues in system memory with the
1122 		 * original depth
1123 		 */
1124 		if (q_depth < 64)
1125 			return -ENOMEM;
1126 	}
1127 
1128 	return q_depth;
1129 }
1130 
1131 static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
1132 				int qid, int depth)
1133 {
1134 	if (qid && dev->cmb && use_cmb_sqes && NVME_CMB_SQS(dev->cmbsz)) {
1135 		unsigned offset = (qid - 1) * roundup(SQ_SIZE(depth),
1136 						      dev->ctrl.page_size);
1137 		nvmeq->sq_dma_addr = dev->cmb_dma_addr + offset;
1138 		nvmeq->sq_cmds_io = dev->cmb + offset;
1139 	} else {
1140 		nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(depth),
1141 					&nvmeq->sq_dma_addr, GFP_KERNEL);
1142 		if (!nvmeq->sq_cmds)
1143 			return -ENOMEM;
1144 	}
1145 
1146 	return 0;
1147 }
1148 
1149 static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
1150 							int depth)
1151 {
1152 	struct nvme_queue *nvmeq = kzalloc(sizeof(*nvmeq), GFP_KERNEL);
1153 	if (!nvmeq)
1154 		return NULL;
1155 
1156 	nvmeq->cqes = dma_zalloc_coherent(dev->dev, CQ_SIZE(depth),
1157 					  &nvmeq->cq_dma_addr, GFP_KERNEL);
1158 	if (!nvmeq->cqes)
1159 		goto free_nvmeq;
1160 
1161 	if (nvme_alloc_sq_cmds(dev, nvmeq, qid, depth))
1162 		goto free_cqdma;
1163 
1164 	nvmeq->q_dmadev = dev->dev;
1165 	nvmeq->dev = dev;
1166 	snprintf(nvmeq->irqname, sizeof(nvmeq->irqname), "nvme%dq%d",
1167 			dev->ctrl.instance, qid);
1168 	spin_lock_init(&nvmeq->q_lock);
1169 	nvmeq->cq_head = 0;
1170 	nvmeq->cq_phase = 1;
1171 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1172 	nvmeq->q_depth = depth;
1173 	nvmeq->qid = qid;
1174 	nvmeq->cq_vector = -1;
1175 	dev->queues[qid] = nvmeq;
1176 
1177 	/* make sure queue descriptor is set before queue count, for kthread */
1178 	mb();
1179 	dev->queue_count++;
1180 
1181 	return nvmeq;
1182 
1183  free_cqdma:
1184 	dma_free_coherent(dev->dev, CQ_SIZE(depth), (void *)nvmeq->cqes,
1185 							nvmeq->cq_dma_addr);
1186  free_nvmeq:
1187 	kfree(nvmeq);
1188 	return NULL;
1189 }
1190 
1191 static int queue_request_irq(struct nvme_dev *dev, struct nvme_queue *nvmeq,
1192 							const char *name)
1193 {
1194 	if (use_threaded_interrupts)
1195 		return request_threaded_irq(dev->entry[nvmeq->cq_vector].vector,
1196 					nvme_irq_check, nvme_irq, IRQF_SHARED,
1197 					name, nvmeq);
1198 	return request_irq(dev->entry[nvmeq->cq_vector].vector, nvme_irq,
1199 				IRQF_SHARED, name, nvmeq);
1200 }
1201 
1202 static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
1203 {
1204 	struct nvme_dev *dev = nvmeq->dev;
1205 
1206 	spin_lock_irq(&nvmeq->q_lock);
1207 	nvmeq->sq_tail = 0;
1208 	nvmeq->cq_head = 0;
1209 	nvmeq->cq_phase = 1;
1210 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1211 	memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth));
1212 	dev->online_queues++;
1213 	spin_unlock_irq(&nvmeq->q_lock);
1214 }
1215 
1216 static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
1217 {
1218 	struct nvme_dev *dev = nvmeq->dev;
1219 	int result;
1220 
1221 	nvmeq->cq_vector = qid - 1;
1222 	result = adapter_alloc_cq(dev, qid, nvmeq);
1223 	if (result < 0)
1224 		return result;
1225 
1226 	result = adapter_alloc_sq(dev, qid, nvmeq);
1227 	if (result < 0)
1228 		goto release_cq;
1229 
1230 	result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
1231 	if (result < 0)
1232 		goto release_sq;
1233 
1234 	nvme_init_queue(nvmeq, qid);
1235 	return result;
1236 
1237  release_sq:
1238 	adapter_delete_sq(dev, qid);
1239  release_cq:
1240 	adapter_delete_cq(dev, qid);
1241 	return result;
1242 }
1243 
1244 static struct blk_mq_ops nvme_mq_admin_ops = {
1245 	.queue_rq	= nvme_queue_rq,
1246 	.complete	= nvme_complete_rq,
1247 	.map_queue	= blk_mq_map_queue,
1248 	.init_hctx	= nvme_admin_init_hctx,
1249 	.exit_hctx      = nvme_admin_exit_hctx,
1250 	.init_request	= nvme_admin_init_request,
1251 	.timeout	= nvme_timeout,
1252 };
1253 
1254 static struct blk_mq_ops nvme_mq_ops = {
1255 	.queue_rq	= nvme_queue_rq,
1256 	.complete	= nvme_complete_rq,
1257 	.map_queue	= blk_mq_map_queue,
1258 	.init_hctx	= nvme_init_hctx,
1259 	.init_request	= nvme_init_request,
1260 	.timeout	= nvme_timeout,
1261 	.poll		= nvme_poll,
1262 };
1263 
1264 static void nvme_dev_remove_admin(struct nvme_dev *dev)
1265 {
1266 	if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q)) {
1267 		/*
1268 		 * If the controller was reset during removal, it's possible
1269 		 * user requests may be waiting on a stopped queue. Start the
1270 		 * queue to flush these to completion.
1271 		 */
1272 		blk_mq_start_stopped_hw_queues(dev->ctrl.admin_q, true);
1273 		blk_cleanup_queue(dev->ctrl.admin_q);
1274 		blk_mq_free_tag_set(&dev->admin_tagset);
1275 	}
1276 }
1277 
1278 static int nvme_alloc_admin_tags(struct nvme_dev *dev)
1279 {
1280 	if (!dev->ctrl.admin_q) {
1281 		dev->admin_tagset.ops = &nvme_mq_admin_ops;
1282 		dev->admin_tagset.nr_hw_queues = 1;
1283 
1284 		/*
1285 		 * Subtract one to leave an empty queue entry for 'Full Queue'
1286 		 * condition. See NVM-Express 1.2 specification, section 4.1.2.
1287 		 */
1288 		dev->admin_tagset.queue_depth = NVME_AQ_BLKMQ_DEPTH - 1;
1289 		dev->admin_tagset.timeout = ADMIN_TIMEOUT;
1290 		dev->admin_tagset.numa_node = dev_to_node(dev->dev);
1291 		dev->admin_tagset.cmd_size = nvme_cmd_size(dev);
1292 		dev->admin_tagset.driver_data = dev;
1293 
1294 		if (blk_mq_alloc_tag_set(&dev->admin_tagset))
1295 			return -ENOMEM;
1296 
1297 		dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
1298 		if (IS_ERR(dev->ctrl.admin_q)) {
1299 			blk_mq_free_tag_set(&dev->admin_tagset);
1300 			return -ENOMEM;
1301 		}
1302 		if (!blk_get_queue(dev->ctrl.admin_q)) {
1303 			nvme_dev_remove_admin(dev);
1304 			dev->ctrl.admin_q = NULL;
1305 			return -ENODEV;
1306 		}
1307 	} else
1308 		blk_mq_start_stopped_hw_queues(dev->ctrl.admin_q, true);
1309 
1310 	return 0;
1311 }
1312 
1313 static int nvme_configure_admin_queue(struct nvme_dev *dev)
1314 {
1315 	int result;
1316 	u32 aqa;
1317 	u64 cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
1318 	struct nvme_queue *nvmeq;
1319 
1320 	dev->subsystem = readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 1) ?
1321 						NVME_CAP_NSSRC(cap) : 0;
1322 
1323 	if (dev->subsystem &&
1324 	    (readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_NSSRO))
1325 		writel(NVME_CSTS_NSSRO, dev->bar + NVME_REG_CSTS);
1326 
1327 	result = nvme_disable_ctrl(&dev->ctrl, cap);
1328 	if (result < 0)
1329 		return result;
1330 
1331 	nvmeq = dev->queues[0];
1332 	if (!nvmeq) {
1333 		nvmeq = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH);
1334 		if (!nvmeq)
1335 			return -ENOMEM;
1336 	}
1337 
1338 	aqa = nvmeq->q_depth - 1;
1339 	aqa |= aqa << 16;
1340 
1341 	writel(aqa, dev->bar + NVME_REG_AQA);
1342 	lo_hi_writeq(nvmeq->sq_dma_addr, dev->bar + NVME_REG_ASQ);
1343 	lo_hi_writeq(nvmeq->cq_dma_addr, dev->bar + NVME_REG_ACQ);
1344 
1345 	result = nvme_enable_ctrl(&dev->ctrl, cap);
1346 	if (result)
1347 		goto free_nvmeq;
1348 
1349 	nvmeq->cq_vector = 0;
1350 	result = queue_request_irq(dev, nvmeq, nvmeq->irqname);
1351 	if (result) {
1352 		nvmeq->cq_vector = -1;
1353 		goto free_nvmeq;
1354 	}
1355 
1356 	return result;
1357 
1358  free_nvmeq:
1359 	nvme_free_queues(dev, 0);
1360 	return result;
1361 }
1362 
1363 static int nvme_kthread(void *data)
1364 {
1365 	struct nvme_dev *dev, *next;
1366 
1367 	while (!kthread_should_stop()) {
1368 		set_current_state(TASK_INTERRUPTIBLE);
1369 		spin_lock(&dev_list_lock);
1370 		list_for_each_entry_safe(dev, next, &dev_list, node) {
1371 			int i;
1372 			u32 csts = readl(dev->bar + NVME_REG_CSTS);
1373 
1374 			/*
1375 			 * Skip controllers currently under reset.
1376 			 */
1377 			if (work_pending(&dev->reset_work) || work_busy(&dev->reset_work))
1378 				continue;
1379 
1380 			if ((dev->subsystem && (csts & NVME_CSTS_NSSRO)) ||
1381 							csts & NVME_CSTS_CFS) {
1382 				if (queue_work(nvme_workq, &dev->reset_work)) {
1383 					dev_warn(dev->dev,
1384 						"Failed status: %x, reset controller\n",
1385 						readl(dev->bar + NVME_REG_CSTS));
1386 				}
1387 				continue;
1388 			}
1389 			for (i = 0; i < dev->queue_count; i++) {
1390 				struct nvme_queue *nvmeq = dev->queues[i];
1391 				if (!nvmeq)
1392 					continue;
1393 				spin_lock_irq(&nvmeq->q_lock);
1394 				nvme_process_cq(nvmeq);
1395 
1396 				while (i == 0 && dev->ctrl.event_limit > 0)
1397 					nvme_submit_async_event(dev);
1398 				spin_unlock_irq(&nvmeq->q_lock);
1399 			}
1400 		}
1401 		spin_unlock(&dev_list_lock);
1402 		schedule_timeout(round_jiffies_relative(HZ));
1403 	}
1404 	return 0;
1405 }
1406 
1407 static int nvme_create_io_queues(struct nvme_dev *dev)
1408 {
1409 	unsigned i;
1410 	int ret = 0;
1411 
1412 	for (i = dev->queue_count; i <= dev->max_qid; i++) {
1413 		if (!nvme_alloc_queue(dev, i, dev->q_depth)) {
1414 			ret = -ENOMEM;
1415 			break;
1416 		}
1417 	}
1418 
1419 	for (i = dev->online_queues; i <= dev->queue_count - 1; i++) {
1420 		ret = nvme_create_queue(dev->queues[i], i);
1421 		if (ret) {
1422 			nvme_free_queues(dev, i);
1423 			break;
1424 		}
1425 	}
1426 
1427 	/*
1428 	 * Ignore failing Create SQ/CQ commands, we can continue with less
1429 	 * than the desired aount of queues, and even a controller without
1430 	 * I/O queues an still be used to issue admin commands.  This might
1431 	 * be useful to upgrade a buggy firmware for example.
1432 	 */
1433 	return ret >= 0 ? 0 : ret;
1434 }
1435 
1436 static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
1437 {
1438 	u64 szu, size, offset;
1439 	u32 cmbloc;
1440 	resource_size_t bar_size;
1441 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1442 	void __iomem *cmb;
1443 	dma_addr_t dma_addr;
1444 
1445 	if (!use_cmb_sqes)
1446 		return NULL;
1447 
1448 	dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
1449 	if (!(NVME_CMB_SZ(dev->cmbsz)))
1450 		return NULL;
1451 
1452 	cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
1453 
1454 	szu = (u64)1 << (12 + 4 * NVME_CMB_SZU(dev->cmbsz));
1455 	size = szu * NVME_CMB_SZ(dev->cmbsz);
1456 	offset = szu * NVME_CMB_OFST(cmbloc);
1457 	bar_size = pci_resource_len(pdev, NVME_CMB_BIR(cmbloc));
1458 
1459 	if (offset > bar_size)
1460 		return NULL;
1461 
1462 	/*
1463 	 * Controllers may support a CMB size larger than their BAR,
1464 	 * for example, due to being behind a bridge. Reduce the CMB to
1465 	 * the reported size of the BAR
1466 	 */
1467 	if (size > bar_size - offset)
1468 		size = bar_size - offset;
1469 
1470 	dma_addr = pci_resource_start(pdev, NVME_CMB_BIR(cmbloc)) + offset;
1471 	cmb = ioremap_wc(dma_addr, size);
1472 	if (!cmb)
1473 		return NULL;
1474 
1475 	dev->cmb_dma_addr = dma_addr;
1476 	dev->cmb_size = size;
1477 	return cmb;
1478 }
1479 
1480 static inline void nvme_release_cmb(struct nvme_dev *dev)
1481 {
1482 	if (dev->cmb) {
1483 		iounmap(dev->cmb);
1484 		dev->cmb = NULL;
1485 	}
1486 }
1487 
1488 static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
1489 {
1490 	return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride);
1491 }
1492 
1493 static int nvme_setup_io_queues(struct nvme_dev *dev)
1494 {
1495 	struct nvme_queue *adminq = dev->queues[0];
1496 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1497 	int result, i, vecs, nr_io_queues, size;
1498 
1499 	nr_io_queues = num_possible_cpus();
1500 	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
1501 	if (result < 0)
1502 		return result;
1503 
1504 	/*
1505 	 * Degraded controllers might return an error when setting the queue
1506 	 * count.  We still want to be able to bring them online and offer
1507 	 * access to the admin queue, as that might be only way to fix them up.
1508 	 */
1509 	if (result > 0) {
1510 		dev_err(dev->dev, "Could not set queue count (%d)\n", result);
1511 		nr_io_queues = 0;
1512 		result = 0;
1513 	}
1514 
1515 	if (dev->cmb && NVME_CMB_SQS(dev->cmbsz)) {
1516 		result = nvme_cmb_qdepth(dev, nr_io_queues,
1517 				sizeof(struct nvme_command));
1518 		if (result > 0)
1519 			dev->q_depth = result;
1520 		else
1521 			nvme_release_cmb(dev);
1522 	}
1523 
1524 	size = db_bar_size(dev, nr_io_queues);
1525 	if (size > 8192) {
1526 		iounmap(dev->bar);
1527 		do {
1528 			dev->bar = ioremap(pci_resource_start(pdev, 0), size);
1529 			if (dev->bar)
1530 				break;
1531 			if (!--nr_io_queues)
1532 				return -ENOMEM;
1533 			size = db_bar_size(dev, nr_io_queues);
1534 		} while (1);
1535 		dev->dbs = dev->bar + 4096;
1536 		adminq->q_db = dev->dbs;
1537 	}
1538 
1539 	/* Deregister the admin queue's interrupt */
1540 	free_irq(dev->entry[0].vector, adminq);
1541 
1542 	/*
1543 	 * If we enable msix early due to not intx, disable it again before
1544 	 * setting up the full range we need.
1545 	 */
1546 	if (!pdev->irq)
1547 		pci_disable_msix(pdev);
1548 
1549 	for (i = 0; i < nr_io_queues; i++)
1550 		dev->entry[i].entry = i;
1551 	vecs = pci_enable_msix_range(pdev, dev->entry, 1, nr_io_queues);
1552 	if (vecs < 0) {
1553 		vecs = pci_enable_msi_range(pdev, 1, min(nr_io_queues, 32));
1554 		if (vecs < 0) {
1555 			vecs = 1;
1556 		} else {
1557 			for (i = 0; i < vecs; i++)
1558 				dev->entry[i].vector = i + pdev->irq;
1559 		}
1560 	}
1561 
1562 	/*
1563 	 * Should investigate if there's a performance win from allocating
1564 	 * more queues than interrupt vectors; it might allow the submission
1565 	 * path to scale better, even if the receive path is limited by the
1566 	 * number of interrupts.
1567 	 */
1568 	nr_io_queues = vecs;
1569 	dev->max_qid = nr_io_queues;
1570 
1571 	result = queue_request_irq(dev, adminq, adminq->irqname);
1572 	if (result) {
1573 		adminq->cq_vector = -1;
1574 		goto free_queues;
1575 	}
1576 
1577 	/* Free previously allocated queues that are no longer usable */
1578 	nvme_free_queues(dev, nr_io_queues + 1);
1579 	return nvme_create_io_queues(dev);
1580 
1581  free_queues:
1582 	nvme_free_queues(dev, 1);
1583 	return result;
1584 }
1585 
1586 static void nvme_set_irq_hints(struct nvme_dev *dev)
1587 {
1588 	struct nvme_queue *nvmeq;
1589 	int i;
1590 
1591 	for (i = 0; i < dev->online_queues; i++) {
1592 		nvmeq = dev->queues[i];
1593 
1594 		if (!nvmeq->tags || !(*nvmeq->tags))
1595 			continue;
1596 
1597 		irq_set_affinity_hint(dev->entry[nvmeq->cq_vector].vector,
1598 					blk_mq_tags_cpumask(*nvmeq->tags));
1599 	}
1600 }
1601 
1602 static void nvme_dev_scan(struct work_struct *work)
1603 {
1604 	struct nvme_dev *dev = container_of(work, struct nvme_dev, scan_work);
1605 
1606 	if (!dev->tagset.tags)
1607 		return;
1608 	nvme_scan_namespaces(&dev->ctrl);
1609 	nvme_set_irq_hints(dev);
1610 }
1611 
1612 static void nvme_del_queue_end(struct request *req, int error)
1613 {
1614 	struct nvme_queue *nvmeq = req->end_io_data;
1615 
1616 	blk_mq_free_request(req);
1617 	complete(&nvmeq->dev->ioq_wait);
1618 }
1619 
1620 static void nvme_del_cq_end(struct request *req, int error)
1621 {
1622 	struct nvme_queue *nvmeq = req->end_io_data;
1623 
1624 	if (!error) {
1625 		unsigned long flags;
1626 
1627 		spin_lock_irqsave(&nvmeq->q_lock, flags);
1628 		nvme_process_cq(nvmeq);
1629 		spin_unlock_irqrestore(&nvmeq->q_lock, flags);
1630 	}
1631 
1632 	nvme_del_queue_end(req, error);
1633 }
1634 
1635 static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
1636 {
1637 	struct request_queue *q = nvmeq->dev->ctrl.admin_q;
1638 	struct request *req;
1639 	struct nvme_command cmd;
1640 
1641 	memset(&cmd, 0, sizeof(cmd));
1642 	cmd.delete_queue.opcode = opcode;
1643 	cmd.delete_queue.qid = cpu_to_le16(nvmeq->qid);
1644 
1645 	req = nvme_alloc_request(q, &cmd, BLK_MQ_REQ_NOWAIT);
1646 	if (IS_ERR(req))
1647 		return PTR_ERR(req);
1648 
1649 	req->timeout = ADMIN_TIMEOUT;
1650 	req->end_io_data = nvmeq;
1651 
1652 	blk_execute_rq_nowait(q, NULL, req, false,
1653 			opcode == nvme_admin_delete_cq ?
1654 				nvme_del_cq_end : nvme_del_queue_end);
1655 	return 0;
1656 }
1657 
1658 static void nvme_disable_io_queues(struct nvme_dev *dev)
1659 {
1660 	int pass;
1661 	unsigned long timeout;
1662 	u8 opcode = nvme_admin_delete_sq;
1663 
1664 	for (pass = 0; pass < 2; pass++) {
1665 		int sent = 0, i = dev->queue_count - 1;
1666 
1667 		reinit_completion(&dev->ioq_wait);
1668  retry:
1669 		timeout = ADMIN_TIMEOUT;
1670 		for (; i > 0; i--) {
1671 			struct nvme_queue *nvmeq = dev->queues[i];
1672 
1673 			if (!pass)
1674 				nvme_suspend_queue(nvmeq);
1675 			if (nvme_delete_queue(nvmeq, opcode))
1676 				break;
1677 			++sent;
1678 		}
1679 		while (sent--) {
1680 			timeout = wait_for_completion_io_timeout(&dev->ioq_wait, timeout);
1681 			if (timeout == 0)
1682 				return;
1683 			if (i)
1684 				goto retry;
1685 		}
1686 		opcode = nvme_admin_delete_cq;
1687 	}
1688 }
1689 
1690 /*
1691  * Return: error value if an error occurred setting up the queues or calling
1692  * Identify Device.  0 if these succeeded, even if adding some of the
1693  * namespaces failed.  At the moment, these failures are silent.  TBD which
1694  * failures should be reported.
1695  */
1696 static int nvme_dev_add(struct nvme_dev *dev)
1697 {
1698 	if (!dev->ctrl.tagset) {
1699 		dev->tagset.ops = &nvme_mq_ops;
1700 		dev->tagset.nr_hw_queues = dev->online_queues - 1;
1701 		dev->tagset.timeout = NVME_IO_TIMEOUT;
1702 		dev->tagset.numa_node = dev_to_node(dev->dev);
1703 		dev->tagset.queue_depth =
1704 				min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH) - 1;
1705 		dev->tagset.cmd_size = nvme_cmd_size(dev);
1706 		dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
1707 		dev->tagset.driver_data = dev;
1708 
1709 		if (blk_mq_alloc_tag_set(&dev->tagset))
1710 			return 0;
1711 		dev->ctrl.tagset = &dev->tagset;
1712 	}
1713 	nvme_queue_scan(dev);
1714 	return 0;
1715 }
1716 
1717 static int nvme_pci_enable(struct nvme_dev *dev)
1718 {
1719 	u64 cap;
1720 	int result = -ENOMEM;
1721 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1722 
1723 	if (pci_enable_device_mem(pdev))
1724 		return result;
1725 
1726 	dev->entry[0].vector = pdev->irq;
1727 	pci_set_master(pdev);
1728 
1729 	if (dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(64)) &&
1730 	    dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(32)))
1731 		goto disable;
1732 
1733 	if (readl(dev->bar + NVME_REG_CSTS) == -1) {
1734 		result = -ENODEV;
1735 		goto disable;
1736 	}
1737 
1738 	/*
1739 	 * Some devices don't advertse INTx interrupts, pre-enable a single
1740 	 * MSIX vec for setup. We'll adjust this later.
1741 	 */
1742 	if (!pdev->irq) {
1743 		result = pci_enable_msix(pdev, dev->entry, 1);
1744 		if (result < 0)
1745 			goto disable;
1746 	}
1747 
1748 	cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
1749 
1750 	dev->q_depth = min_t(int, NVME_CAP_MQES(cap) + 1, NVME_Q_DEPTH);
1751 	dev->db_stride = 1 << NVME_CAP_STRIDE(cap);
1752 	dev->dbs = dev->bar + 4096;
1753 
1754 	/*
1755 	 * Temporary fix for the Apple controller found in the MacBook8,1 and
1756 	 * some MacBook7,1 to avoid controller resets and data loss.
1757 	 */
1758 	if (pdev->vendor == PCI_VENDOR_ID_APPLE && pdev->device == 0x2001) {
1759 		dev->q_depth = 2;
1760 		dev_warn(dev->dev, "detected Apple NVMe controller, set "
1761 			"queue depth=%u to work around controller resets\n",
1762 			dev->q_depth);
1763 	}
1764 
1765 	if (readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 2))
1766 		dev->cmb = nvme_map_cmb(dev);
1767 
1768 	pci_enable_pcie_error_reporting(pdev);
1769 	pci_save_state(pdev);
1770 	return 0;
1771 
1772  disable:
1773 	pci_disable_device(pdev);
1774 	return result;
1775 }
1776 
1777 static void nvme_dev_unmap(struct nvme_dev *dev)
1778 {
1779 	if (dev->bar)
1780 		iounmap(dev->bar);
1781 	pci_release_regions(to_pci_dev(dev->dev));
1782 }
1783 
1784 static void nvme_pci_disable(struct nvme_dev *dev)
1785 {
1786 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1787 
1788 	if (pdev->msi_enabled)
1789 		pci_disable_msi(pdev);
1790 	else if (pdev->msix_enabled)
1791 		pci_disable_msix(pdev);
1792 
1793 	if (pci_is_enabled(pdev)) {
1794 		pci_disable_pcie_error_reporting(pdev);
1795 		pci_disable_device(pdev);
1796 	}
1797 }
1798 
1799 static int nvme_dev_list_add(struct nvme_dev *dev)
1800 {
1801 	bool start_thread = false;
1802 
1803 	spin_lock(&dev_list_lock);
1804 	if (list_empty(&dev_list) && IS_ERR_OR_NULL(nvme_thread)) {
1805 		start_thread = true;
1806 		nvme_thread = NULL;
1807 	}
1808 	list_add(&dev->node, &dev_list);
1809 	spin_unlock(&dev_list_lock);
1810 
1811 	if (start_thread) {
1812 		nvme_thread = kthread_run(nvme_kthread, NULL, "nvme");
1813 		wake_up_all(&nvme_kthread_wait);
1814 	} else
1815 		wait_event_killable(nvme_kthread_wait, nvme_thread);
1816 
1817 	if (IS_ERR_OR_NULL(nvme_thread))
1818 		return nvme_thread ? PTR_ERR(nvme_thread) : -EINTR;
1819 
1820 	return 0;
1821 }
1822 
1823 /*
1824 * Remove the node from the device list and check
1825 * for whether or not we need to stop the nvme_thread.
1826 */
1827 static void nvme_dev_list_remove(struct nvme_dev *dev)
1828 {
1829 	struct task_struct *tmp = NULL;
1830 
1831 	spin_lock(&dev_list_lock);
1832 	list_del_init(&dev->node);
1833 	if (list_empty(&dev_list) && !IS_ERR_OR_NULL(nvme_thread)) {
1834 		tmp = nvme_thread;
1835 		nvme_thread = NULL;
1836 	}
1837 	spin_unlock(&dev_list_lock);
1838 
1839 	if (tmp)
1840 		kthread_stop(tmp);
1841 }
1842 
1843 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
1844 {
1845 	int i;
1846 	u32 csts = -1;
1847 
1848 	nvme_dev_list_remove(dev);
1849 
1850 	mutex_lock(&dev->shutdown_lock);
1851 	if (pci_is_enabled(to_pci_dev(dev->dev))) {
1852 		nvme_stop_queues(&dev->ctrl);
1853 		csts = readl(dev->bar + NVME_REG_CSTS);
1854 	}
1855 	if (csts & NVME_CSTS_CFS || !(csts & NVME_CSTS_RDY)) {
1856 		for (i = dev->queue_count - 1; i >= 0; i--) {
1857 			struct nvme_queue *nvmeq = dev->queues[i];
1858 			nvme_suspend_queue(nvmeq);
1859 		}
1860 	} else {
1861 		nvme_disable_io_queues(dev);
1862 		nvme_disable_admin_queue(dev, shutdown);
1863 	}
1864 	nvme_pci_disable(dev);
1865 
1866 	for (i = dev->queue_count - 1; i >= 0; i--)
1867 		nvme_clear_queue(dev->queues[i]);
1868 	mutex_unlock(&dev->shutdown_lock);
1869 }
1870 
1871 static int nvme_setup_prp_pools(struct nvme_dev *dev)
1872 {
1873 	dev->prp_page_pool = dma_pool_create("prp list page", dev->dev,
1874 						PAGE_SIZE, PAGE_SIZE, 0);
1875 	if (!dev->prp_page_pool)
1876 		return -ENOMEM;
1877 
1878 	/* Optimisation for I/Os between 4k and 128k */
1879 	dev->prp_small_pool = dma_pool_create("prp list 256", dev->dev,
1880 						256, 256, 0);
1881 	if (!dev->prp_small_pool) {
1882 		dma_pool_destroy(dev->prp_page_pool);
1883 		return -ENOMEM;
1884 	}
1885 	return 0;
1886 }
1887 
1888 static void nvme_release_prp_pools(struct nvme_dev *dev)
1889 {
1890 	dma_pool_destroy(dev->prp_page_pool);
1891 	dma_pool_destroy(dev->prp_small_pool);
1892 }
1893 
1894 static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
1895 {
1896 	struct nvme_dev *dev = to_nvme_dev(ctrl);
1897 
1898 	put_device(dev->dev);
1899 	if (dev->tagset.tags)
1900 		blk_mq_free_tag_set(&dev->tagset);
1901 	if (dev->ctrl.admin_q)
1902 		blk_put_queue(dev->ctrl.admin_q);
1903 	kfree(dev->queues);
1904 	kfree(dev->entry);
1905 	kfree(dev);
1906 }
1907 
1908 static void nvme_remove_dead_ctrl(struct nvme_dev *dev, int status)
1909 {
1910 	dev_warn(dev->dev, "Removing after probe failure status: %d\n", status);
1911 
1912 	kref_get(&dev->ctrl.kref);
1913 	nvme_dev_disable(dev, false);
1914 	if (!schedule_work(&dev->remove_work))
1915 		nvme_put_ctrl(&dev->ctrl);
1916 }
1917 
1918 static void nvme_reset_work(struct work_struct *work)
1919 {
1920 	struct nvme_dev *dev = container_of(work, struct nvme_dev, reset_work);
1921 	int result = -ENODEV;
1922 
1923 	if (WARN_ON(test_bit(NVME_CTRL_RESETTING, &dev->flags)))
1924 		goto out;
1925 
1926 	/*
1927 	 * If we're called to reset a live controller first shut it down before
1928 	 * moving on.
1929 	 */
1930 	if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
1931 		nvme_dev_disable(dev, false);
1932 
1933 	set_bit(NVME_CTRL_RESETTING, &dev->flags);
1934 
1935 	result = nvme_pci_enable(dev);
1936 	if (result)
1937 		goto out;
1938 
1939 	result = nvme_configure_admin_queue(dev);
1940 	if (result)
1941 		goto out;
1942 
1943 	nvme_init_queue(dev->queues[0], 0);
1944 	result = nvme_alloc_admin_tags(dev);
1945 	if (result)
1946 		goto out;
1947 
1948 	result = nvme_init_identify(&dev->ctrl);
1949 	if (result)
1950 		goto out;
1951 
1952 	result = nvme_setup_io_queues(dev);
1953 	if (result)
1954 		goto out;
1955 
1956 	dev->ctrl.event_limit = NVME_NR_AEN_COMMANDS;
1957 
1958 	result = nvme_dev_list_add(dev);
1959 	if (result)
1960 		goto out;
1961 
1962 	/*
1963 	 * Keep the controller around but remove all namespaces if we don't have
1964 	 * any working I/O queue.
1965 	 */
1966 	if (dev->online_queues < 2) {
1967 		dev_warn(dev->dev, "IO queues not created\n");
1968 		nvme_remove_namespaces(&dev->ctrl);
1969 	} else {
1970 		nvme_start_queues(&dev->ctrl);
1971 		nvme_dev_add(dev);
1972 	}
1973 
1974 	clear_bit(NVME_CTRL_RESETTING, &dev->flags);
1975 	return;
1976 
1977  out:
1978 	nvme_remove_dead_ctrl(dev, result);
1979 }
1980 
1981 static void nvme_remove_dead_ctrl_work(struct work_struct *work)
1982 {
1983 	struct nvme_dev *dev = container_of(work, struct nvme_dev, remove_work);
1984 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1985 
1986 	nvme_kill_queues(&dev->ctrl);
1987 	if (pci_get_drvdata(pdev))
1988 		pci_stop_and_remove_bus_device_locked(pdev);
1989 	nvme_put_ctrl(&dev->ctrl);
1990 }
1991 
1992 static int nvme_reset(struct nvme_dev *dev)
1993 {
1994 	if (!dev->ctrl.admin_q || blk_queue_dying(dev->ctrl.admin_q))
1995 		return -ENODEV;
1996 
1997 	if (!queue_work(nvme_workq, &dev->reset_work))
1998 		return -EBUSY;
1999 
2000 	flush_work(&dev->reset_work);
2001 	return 0;
2002 }
2003 
2004 static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
2005 {
2006 	*val = readl(to_nvme_dev(ctrl)->bar + off);
2007 	return 0;
2008 }
2009 
2010 static int nvme_pci_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
2011 {
2012 	writel(val, to_nvme_dev(ctrl)->bar + off);
2013 	return 0;
2014 }
2015 
2016 static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
2017 {
2018 	*val = readq(to_nvme_dev(ctrl)->bar + off);
2019 	return 0;
2020 }
2021 
2022 static bool nvme_pci_io_incapable(struct nvme_ctrl *ctrl)
2023 {
2024 	struct nvme_dev *dev = to_nvme_dev(ctrl);
2025 
2026 	return !dev->bar || dev->online_queues < 2;
2027 }
2028 
2029 static int nvme_pci_reset_ctrl(struct nvme_ctrl *ctrl)
2030 {
2031 	return nvme_reset(to_nvme_dev(ctrl));
2032 }
2033 
2034 static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
2035 	.reg_read32		= nvme_pci_reg_read32,
2036 	.reg_write32		= nvme_pci_reg_write32,
2037 	.reg_read64		= nvme_pci_reg_read64,
2038 	.io_incapable		= nvme_pci_io_incapable,
2039 	.reset_ctrl		= nvme_pci_reset_ctrl,
2040 	.free_ctrl		= nvme_pci_free_ctrl,
2041 };
2042 
2043 static int nvme_dev_map(struct nvme_dev *dev)
2044 {
2045 	int bars;
2046 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2047 
2048 	bars = pci_select_bars(pdev, IORESOURCE_MEM);
2049 	if (!bars)
2050 		return -ENODEV;
2051 	if (pci_request_selected_regions(pdev, bars, "nvme"))
2052 		return -ENODEV;
2053 
2054 	dev->bar = ioremap(pci_resource_start(pdev, 0), 8192);
2055 	if (!dev->bar)
2056 		goto release;
2057 
2058        return 0;
2059   release:
2060        pci_release_regions(pdev);
2061        return -ENODEV;
2062 }
2063 
2064 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
2065 {
2066 	int node, result = -ENOMEM;
2067 	struct nvme_dev *dev;
2068 
2069 	node = dev_to_node(&pdev->dev);
2070 	if (node == NUMA_NO_NODE)
2071 		set_dev_node(&pdev->dev, 0);
2072 
2073 	dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
2074 	if (!dev)
2075 		return -ENOMEM;
2076 	dev->entry = kzalloc_node(num_possible_cpus() * sizeof(*dev->entry),
2077 							GFP_KERNEL, node);
2078 	if (!dev->entry)
2079 		goto free;
2080 	dev->queues = kzalloc_node((num_possible_cpus() + 1) * sizeof(void *),
2081 							GFP_KERNEL, node);
2082 	if (!dev->queues)
2083 		goto free;
2084 
2085 	dev->dev = get_device(&pdev->dev);
2086 	pci_set_drvdata(pdev, dev);
2087 
2088 	result = nvme_dev_map(dev);
2089 	if (result)
2090 		goto free;
2091 
2092 	INIT_LIST_HEAD(&dev->node);
2093 	INIT_WORK(&dev->scan_work, nvme_dev_scan);
2094 	INIT_WORK(&dev->reset_work, nvme_reset_work);
2095 	INIT_WORK(&dev->remove_work, nvme_remove_dead_ctrl_work);
2096 	mutex_init(&dev->shutdown_lock);
2097 	init_completion(&dev->ioq_wait);
2098 
2099 	result = nvme_setup_prp_pools(dev);
2100 	if (result)
2101 		goto put_pci;
2102 
2103 	result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
2104 			id->driver_data);
2105 	if (result)
2106 		goto release_pools;
2107 
2108 	queue_work(nvme_workq, &dev->reset_work);
2109 	return 0;
2110 
2111  release_pools:
2112 	nvme_release_prp_pools(dev);
2113  put_pci:
2114 	put_device(dev->dev);
2115 	nvme_dev_unmap(dev);
2116  free:
2117 	kfree(dev->queues);
2118 	kfree(dev->entry);
2119 	kfree(dev);
2120 	return result;
2121 }
2122 
2123 static void nvme_reset_notify(struct pci_dev *pdev, bool prepare)
2124 {
2125 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2126 
2127 	if (prepare)
2128 		nvme_dev_disable(dev, false);
2129 	else
2130 		queue_work(nvme_workq, &dev->reset_work);
2131 }
2132 
2133 static void nvme_shutdown(struct pci_dev *pdev)
2134 {
2135 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2136 	nvme_dev_disable(dev, true);
2137 }
2138 
2139 /*
2140  * The driver's remove may be called on a device in a partially initialized
2141  * state. This function must not have any dependencies on the device state in
2142  * order to proceed.
2143  */
2144 static void nvme_remove(struct pci_dev *pdev)
2145 {
2146 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2147 
2148 	set_bit(NVME_CTRL_REMOVING, &dev->flags);
2149 	pci_set_drvdata(pdev, NULL);
2150 	flush_work(&dev->scan_work);
2151 	nvme_remove_namespaces(&dev->ctrl);
2152 	nvme_uninit_ctrl(&dev->ctrl);
2153 	nvme_dev_disable(dev, true);
2154 	flush_work(&dev->reset_work);
2155 	nvme_dev_remove_admin(dev);
2156 	nvme_free_queues(dev, 0);
2157 	nvme_release_cmb(dev);
2158 	nvme_release_prp_pools(dev);
2159 	nvme_dev_unmap(dev);
2160 	nvme_put_ctrl(&dev->ctrl);
2161 }
2162 
2163 #ifdef CONFIG_PM_SLEEP
2164 static int nvme_suspend(struct device *dev)
2165 {
2166 	struct pci_dev *pdev = to_pci_dev(dev);
2167 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2168 
2169 	nvme_dev_disable(ndev, true);
2170 	return 0;
2171 }
2172 
2173 static int nvme_resume(struct device *dev)
2174 {
2175 	struct pci_dev *pdev = to_pci_dev(dev);
2176 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2177 
2178 	queue_work(nvme_workq, &ndev->reset_work);
2179 	return 0;
2180 }
2181 #endif
2182 
2183 static SIMPLE_DEV_PM_OPS(nvme_dev_pm_ops, nvme_suspend, nvme_resume);
2184 
2185 static pci_ers_result_t nvme_error_detected(struct pci_dev *pdev,
2186 						pci_channel_state_t state)
2187 {
2188 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2189 
2190 	/*
2191 	 * A frozen channel requires a reset. When detected, this method will
2192 	 * shutdown the controller to quiesce. The controller will be restarted
2193 	 * after the slot reset through driver's slot_reset callback.
2194 	 */
2195 	dev_warn(&pdev->dev, "error detected: state:%d\n", state);
2196 	switch (state) {
2197 	case pci_channel_io_normal:
2198 		return PCI_ERS_RESULT_CAN_RECOVER;
2199 	case pci_channel_io_frozen:
2200 		nvme_dev_disable(dev, false);
2201 		return PCI_ERS_RESULT_NEED_RESET;
2202 	case pci_channel_io_perm_failure:
2203 		return PCI_ERS_RESULT_DISCONNECT;
2204 	}
2205 	return PCI_ERS_RESULT_NEED_RESET;
2206 }
2207 
2208 static pci_ers_result_t nvme_slot_reset(struct pci_dev *pdev)
2209 {
2210 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2211 
2212 	dev_info(&pdev->dev, "restart after slot reset\n");
2213 	pci_restore_state(pdev);
2214 	queue_work(nvme_workq, &dev->reset_work);
2215 	return PCI_ERS_RESULT_RECOVERED;
2216 }
2217 
2218 static void nvme_error_resume(struct pci_dev *pdev)
2219 {
2220 	pci_cleanup_aer_uncorrect_error_status(pdev);
2221 }
2222 
2223 static const struct pci_error_handlers nvme_err_handler = {
2224 	.error_detected	= nvme_error_detected,
2225 	.slot_reset	= nvme_slot_reset,
2226 	.resume		= nvme_error_resume,
2227 	.reset_notify	= nvme_reset_notify,
2228 };
2229 
2230 /* Move to pci_ids.h later */
2231 #define PCI_CLASS_STORAGE_EXPRESS	0x010802
2232 
2233 static const struct pci_device_id nvme_id_table[] = {
2234 	{ PCI_VDEVICE(INTEL, 0x0953),
2235 		.driver_data = NVME_QUIRK_STRIPE_SIZE, },
2236 	{ PCI_VDEVICE(INTEL, 0x5845),	/* Qemu emulated controller */
2237 		.driver_data = NVME_QUIRK_IDENTIFY_CNS, },
2238 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
2239 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
2240 	{ 0, }
2241 };
2242 MODULE_DEVICE_TABLE(pci, nvme_id_table);
2243 
2244 static struct pci_driver nvme_driver = {
2245 	.name		= "nvme",
2246 	.id_table	= nvme_id_table,
2247 	.probe		= nvme_probe,
2248 	.remove		= nvme_remove,
2249 	.shutdown	= nvme_shutdown,
2250 	.driver		= {
2251 		.pm	= &nvme_dev_pm_ops,
2252 	},
2253 	.err_handler	= &nvme_err_handler,
2254 };
2255 
2256 static int __init nvme_init(void)
2257 {
2258 	int result;
2259 
2260 	init_waitqueue_head(&nvme_kthread_wait);
2261 
2262 	nvme_workq = alloc_workqueue("nvme", WQ_UNBOUND | WQ_MEM_RECLAIM, 0);
2263 	if (!nvme_workq)
2264 		return -ENOMEM;
2265 
2266 	result = nvme_core_init();
2267 	if (result < 0)
2268 		goto kill_workq;
2269 
2270 	result = pci_register_driver(&nvme_driver);
2271 	if (result)
2272 		goto core_exit;
2273 	return 0;
2274 
2275  core_exit:
2276 	nvme_core_exit();
2277  kill_workq:
2278 	destroy_workqueue(nvme_workq);
2279 	return result;
2280 }
2281 
2282 static void __exit nvme_exit(void)
2283 {
2284 	pci_unregister_driver(&nvme_driver);
2285 	nvme_core_exit();
2286 	destroy_workqueue(nvme_workq);
2287 	BUG_ON(nvme_thread && !IS_ERR(nvme_thread));
2288 	_nvme_check_size();
2289 }
2290 
2291 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
2292 MODULE_LICENSE("GPL");
2293 MODULE_VERSION("1.0");
2294 module_init(nvme_init);
2295 module_exit(nvme_exit);
2296