xref: /openbmc/linux/drivers/nvme/host/pci.c (revision 161b8be2)
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/blk-mq-pci.h>
20 #include <linux/dmi.h>
21 #include <linux/init.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 #include <linux/mutex.h>
27 #include <linux/pci.h>
28 #include <linux/poison.h>
29 #include <linux/t10-pi.h>
30 #include <linux/timer.h>
31 #include <linux/types.h>
32 #include <linux/io-64-nonatomic-lo-hi.h>
33 #include <asm/unaligned.h>
34 #include <linux/sed-opal.h>
35 
36 #include "nvme.h"
37 
38 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
39 #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
40 
41 /*
42  * We handle AEN commands ourselves and don't even let the
43  * block layer know about them.
44  */
45 #define NVME_AQ_BLKMQ_DEPTH	(NVME_AQ_DEPTH - NVME_NR_AERS)
46 
47 static int use_threaded_interrupts;
48 module_param(use_threaded_interrupts, int, 0);
49 
50 static bool use_cmb_sqes = true;
51 module_param(use_cmb_sqes, bool, 0644);
52 MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes");
53 
54 static unsigned int max_host_mem_size_mb = 128;
55 module_param(max_host_mem_size_mb, uint, 0444);
56 MODULE_PARM_DESC(max_host_mem_size_mb,
57 	"Maximum Host Memory Buffer (HMB) size per controller (in MiB)");
58 
59 static int io_queue_depth_set(const char *val, const struct kernel_param *kp);
60 static const struct kernel_param_ops io_queue_depth_ops = {
61 	.set = io_queue_depth_set,
62 	.get = param_get_int,
63 };
64 
65 static int io_queue_depth = 1024;
66 module_param_cb(io_queue_depth, &io_queue_depth_ops, &io_queue_depth, 0644);
67 MODULE_PARM_DESC(io_queue_depth, "set io queue depth, should >= 2");
68 
69 struct nvme_dev;
70 struct nvme_queue;
71 
72 static void nvme_process_cq(struct nvme_queue *nvmeq);
73 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
74 
75 /*
76  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
77  */
78 struct nvme_dev {
79 	struct nvme_queue **queues;
80 	struct blk_mq_tag_set tagset;
81 	struct blk_mq_tag_set admin_tagset;
82 	u32 __iomem *dbs;
83 	struct device *dev;
84 	struct dma_pool *prp_page_pool;
85 	struct dma_pool *prp_small_pool;
86 	unsigned online_queues;
87 	unsigned max_qid;
88 	int q_depth;
89 	u32 db_stride;
90 	void __iomem *bar;
91 	unsigned long bar_mapped_size;
92 	struct work_struct remove_work;
93 	struct mutex shutdown_lock;
94 	bool subsystem;
95 	void __iomem *cmb;
96 	dma_addr_t cmb_dma_addr;
97 	u64 cmb_size;
98 	u32 cmbsz;
99 	u32 cmbloc;
100 	struct nvme_ctrl ctrl;
101 	struct completion ioq_wait;
102 
103 	/* shadow doorbell buffer support: */
104 	u32 *dbbuf_dbs;
105 	dma_addr_t dbbuf_dbs_dma_addr;
106 	u32 *dbbuf_eis;
107 	dma_addr_t dbbuf_eis_dma_addr;
108 
109 	/* host memory buffer support: */
110 	u64 host_mem_size;
111 	u32 nr_host_mem_descs;
112 	dma_addr_t host_mem_descs_dma;
113 	struct nvme_host_mem_buf_desc *host_mem_descs;
114 	void **host_mem_desc_bufs;
115 };
116 
117 static int io_queue_depth_set(const char *val, const struct kernel_param *kp)
118 {
119 	int n = 0, ret;
120 
121 	ret = kstrtoint(val, 10, &n);
122 	if (ret != 0 || n < 2)
123 		return -EINVAL;
124 
125 	return param_set_int(val, kp);
126 }
127 
128 static inline unsigned int sq_idx(unsigned int qid, u32 stride)
129 {
130 	return qid * 2 * stride;
131 }
132 
133 static inline unsigned int cq_idx(unsigned int qid, u32 stride)
134 {
135 	return (qid * 2 + 1) * stride;
136 }
137 
138 static inline struct nvme_dev *to_nvme_dev(struct nvme_ctrl *ctrl)
139 {
140 	return container_of(ctrl, struct nvme_dev, ctrl);
141 }
142 
143 /*
144  * An NVM Express queue.  Each device has at least two (one for admin
145  * commands and one for I/O commands).
146  */
147 struct nvme_queue {
148 	struct device *q_dmadev;
149 	struct nvme_dev *dev;
150 	spinlock_t q_lock;
151 	struct nvme_command *sq_cmds;
152 	struct nvme_command __iomem *sq_cmds_io;
153 	volatile struct nvme_completion *cqes;
154 	struct blk_mq_tags **tags;
155 	dma_addr_t sq_dma_addr;
156 	dma_addr_t cq_dma_addr;
157 	u32 __iomem *q_db;
158 	u16 q_depth;
159 	s16 cq_vector;
160 	u16 sq_tail;
161 	u16 cq_head;
162 	u16 qid;
163 	u8 cq_phase;
164 	u8 cqe_seen;
165 	u32 *dbbuf_sq_db;
166 	u32 *dbbuf_cq_db;
167 	u32 *dbbuf_sq_ei;
168 	u32 *dbbuf_cq_ei;
169 };
170 
171 /*
172  * The nvme_iod describes the data in an I/O, including the list of PRP
173  * entries.  You can't see it in this data structure because C doesn't let
174  * me express that.  Use nvme_init_iod to ensure there's enough space
175  * allocated to store the PRP list.
176  */
177 struct nvme_iod {
178 	struct nvme_request req;
179 	struct nvme_queue *nvmeq;
180 	int aborted;
181 	int npages;		/* In the PRP list. 0 means small pool in use */
182 	int nents;		/* Used in scatterlist */
183 	int length;		/* Of data, in bytes */
184 	dma_addr_t first_dma;
185 	struct scatterlist meta_sg; /* metadata requires single contiguous buffer */
186 	struct scatterlist *sg;
187 	struct scatterlist inline_sg[0];
188 };
189 
190 /*
191  * Check we didin't inadvertently grow the command struct
192  */
193 static inline void _nvme_check_size(void)
194 {
195 	BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
196 	BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
197 	BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
198 	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
199 	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
200 	BUILD_BUG_ON(sizeof(struct nvme_format_cmd) != 64);
201 	BUILD_BUG_ON(sizeof(struct nvme_abort_cmd) != 64);
202 	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
203 	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != NVME_IDENTIFY_DATA_SIZE);
204 	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != NVME_IDENTIFY_DATA_SIZE);
205 	BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
206 	BUILD_BUG_ON(sizeof(struct nvme_smart_log) != 512);
207 	BUILD_BUG_ON(sizeof(struct nvme_dbbuf) != 64);
208 }
209 
210 static inline unsigned int nvme_dbbuf_size(u32 stride)
211 {
212 	return ((num_possible_cpus() + 1) * 8 * stride);
213 }
214 
215 static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
216 {
217 	unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
218 
219 	if (dev->dbbuf_dbs)
220 		return 0;
221 
222 	dev->dbbuf_dbs = dma_alloc_coherent(dev->dev, mem_size,
223 					    &dev->dbbuf_dbs_dma_addr,
224 					    GFP_KERNEL);
225 	if (!dev->dbbuf_dbs)
226 		return -ENOMEM;
227 	dev->dbbuf_eis = dma_alloc_coherent(dev->dev, mem_size,
228 					    &dev->dbbuf_eis_dma_addr,
229 					    GFP_KERNEL);
230 	if (!dev->dbbuf_eis) {
231 		dma_free_coherent(dev->dev, mem_size,
232 				  dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
233 		dev->dbbuf_dbs = NULL;
234 		return -ENOMEM;
235 	}
236 
237 	return 0;
238 }
239 
240 static void nvme_dbbuf_dma_free(struct nvme_dev *dev)
241 {
242 	unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
243 
244 	if (dev->dbbuf_dbs) {
245 		dma_free_coherent(dev->dev, mem_size,
246 				  dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
247 		dev->dbbuf_dbs = NULL;
248 	}
249 	if (dev->dbbuf_eis) {
250 		dma_free_coherent(dev->dev, mem_size,
251 				  dev->dbbuf_eis, dev->dbbuf_eis_dma_addr);
252 		dev->dbbuf_eis = NULL;
253 	}
254 }
255 
256 static void nvme_dbbuf_init(struct nvme_dev *dev,
257 			    struct nvme_queue *nvmeq, int qid)
258 {
259 	if (!dev->dbbuf_dbs || !qid)
260 		return;
261 
262 	nvmeq->dbbuf_sq_db = &dev->dbbuf_dbs[sq_idx(qid, dev->db_stride)];
263 	nvmeq->dbbuf_cq_db = &dev->dbbuf_dbs[cq_idx(qid, dev->db_stride)];
264 	nvmeq->dbbuf_sq_ei = &dev->dbbuf_eis[sq_idx(qid, dev->db_stride)];
265 	nvmeq->dbbuf_cq_ei = &dev->dbbuf_eis[cq_idx(qid, dev->db_stride)];
266 }
267 
268 static void nvme_dbbuf_set(struct nvme_dev *dev)
269 {
270 	struct nvme_command c;
271 
272 	if (!dev->dbbuf_dbs)
273 		return;
274 
275 	memset(&c, 0, sizeof(c));
276 	c.dbbuf.opcode = nvme_admin_dbbuf;
277 	c.dbbuf.prp1 = cpu_to_le64(dev->dbbuf_dbs_dma_addr);
278 	c.dbbuf.prp2 = cpu_to_le64(dev->dbbuf_eis_dma_addr);
279 
280 	if (nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0)) {
281 		dev_warn(dev->ctrl.device, "unable to set dbbuf\n");
282 		/* Free memory and continue on */
283 		nvme_dbbuf_dma_free(dev);
284 	}
285 }
286 
287 static inline int nvme_dbbuf_need_event(u16 event_idx, u16 new_idx, u16 old)
288 {
289 	return (u16)(new_idx - event_idx - 1) < (u16)(new_idx - old);
290 }
291 
292 /* Update dbbuf and return true if an MMIO is required */
293 static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db,
294 					      volatile u32 *dbbuf_ei)
295 {
296 	if (dbbuf_db) {
297 		u16 old_value;
298 
299 		/*
300 		 * Ensure that the queue is written before updating
301 		 * the doorbell in memory
302 		 */
303 		wmb();
304 
305 		old_value = *dbbuf_db;
306 		*dbbuf_db = value;
307 
308 		if (!nvme_dbbuf_need_event(*dbbuf_ei, value, old_value))
309 			return false;
310 	}
311 
312 	return true;
313 }
314 
315 /*
316  * Max size of iod being embedded in the request payload
317  */
318 #define NVME_INT_PAGES		2
319 #define NVME_INT_BYTES(dev)	(NVME_INT_PAGES * (dev)->ctrl.page_size)
320 
321 /*
322  * Will slightly overestimate the number of pages needed.  This is OK
323  * as it only leads to a small amount of wasted memory for the lifetime of
324  * the I/O.
325  */
326 static int nvme_npages(unsigned size, struct nvme_dev *dev)
327 {
328 	unsigned nprps = DIV_ROUND_UP(size + dev->ctrl.page_size,
329 				      dev->ctrl.page_size);
330 	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
331 }
332 
333 static unsigned int nvme_iod_alloc_size(struct nvme_dev *dev,
334 		unsigned int size, unsigned int nseg)
335 {
336 	return sizeof(__le64 *) * nvme_npages(size, dev) +
337 			sizeof(struct scatterlist) * nseg;
338 }
339 
340 static unsigned int nvme_cmd_size(struct nvme_dev *dev)
341 {
342 	return sizeof(struct nvme_iod) +
343 		nvme_iod_alloc_size(dev, NVME_INT_BYTES(dev), NVME_INT_PAGES);
344 }
345 
346 static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
347 				unsigned int hctx_idx)
348 {
349 	struct nvme_dev *dev = data;
350 	struct nvme_queue *nvmeq = dev->queues[0];
351 
352 	WARN_ON(hctx_idx != 0);
353 	WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);
354 	WARN_ON(nvmeq->tags);
355 
356 	hctx->driver_data = nvmeq;
357 	nvmeq->tags = &dev->admin_tagset.tags[0];
358 	return 0;
359 }
360 
361 static void nvme_admin_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
362 {
363 	struct nvme_queue *nvmeq = hctx->driver_data;
364 
365 	nvmeq->tags = NULL;
366 }
367 
368 static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
369 			  unsigned int hctx_idx)
370 {
371 	struct nvme_dev *dev = data;
372 	struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
373 
374 	if (!nvmeq->tags)
375 		nvmeq->tags = &dev->tagset.tags[hctx_idx];
376 
377 	WARN_ON(dev->tagset.tags[hctx_idx] != hctx->tags);
378 	hctx->driver_data = nvmeq;
379 	return 0;
380 }
381 
382 static int nvme_init_request(struct blk_mq_tag_set *set, struct request *req,
383 		unsigned int hctx_idx, unsigned int numa_node)
384 {
385 	struct nvme_dev *dev = set->driver_data;
386 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
387 	int queue_idx = (set == &dev->tagset) ? hctx_idx + 1 : 0;
388 	struct nvme_queue *nvmeq = dev->queues[queue_idx];
389 
390 	BUG_ON(!nvmeq);
391 	iod->nvmeq = nvmeq;
392 	return 0;
393 }
394 
395 static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
396 {
397 	struct nvme_dev *dev = set->driver_data;
398 
399 	return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev));
400 }
401 
402 /**
403  * __nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
404  * @nvmeq: The queue to use
405  * @cmd: The command to send
406  *
407  * Safe to use from interrupt context
408  */
409 static void __nvme_submit_cmd(struct nvme_queue *nvmeq,
410 						struct nvme_command *cmd)
411 {
412 	u16 tail = nvmeq->sq_tail;
413 
414 	if (nvmeq->sq_cmds_io)
415 		memcpy_toio(&nvmeq->sq_cmds_io[tail], cmd, sizeof(*cmd));
416 	else
417 		memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
418 
419 	if (++tail == nvmeq->q_depth)
420 		tail = 0;
421 	if (nvme_dbbuf_update_and_check_event(tail, nvmeq->dbbuf_sq_db,
422 					      nvmeq->dbbuf_sq_ei))
423 		writel(tail, nvmeq->q_db);
424 	nvmeq->sq_tail = tail;
425 }
426 
427 static __le64 **iod_list(struct request *req)
428 {
429 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
430 	return (__le64 **)(iod->sg + blk_rq_nr_phys_segments(req));
431 }
432 
433 static blk_status_t nvme_init_iod(struct request *rq, struct nvme_dev *dev)
434 {
435 	struct nvme_iod *iod = blk_mq_rq_to_pdu(rq);
436 	int nseg = blk_rq_nr_phys_segments(rq);
437 	unsigned int size = blk_rq_payload_bytes(rq);
438 
439 	if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
440 		iod->sg = kmalloc(nvme_iod_alloc_size(dev, size, nseg), GFP_ATOMIC);
441 		if (!iod->sg)
442 			return BLK_STS_RESOURCE;
443 	} else {
444 		iod->sg = iod->inline_sg;
445 	}
446 
447 	iod->aborted = 0;
448 	iod->npages = -1;
449 	iod->nents = 0;
450 	iod->length = size;
451 
452 	return BLK_STS_OK;
453 }
454 
455 static void nvme_free_iod(struct nvme_dev *dev, struct request *req)
456 {
457 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
458 	const int last_prp = dev->ctrl.page_size / 8 - 1;
459 	int i;
460 	__le64 **list = iod_list(req);
461 	dma_addr_t prp_dma = iod->first_dma;
462 
463 	if (iod->npages == 0)
464 		dma_pool_free(dev->prp_small_pool, list[0], prp_dma);
465 	for (i = 0; i < iod->npages; i++) {
466 		__le64 *prp_list = list[i];
467 		dma_addr_t next_prp_dma = le64_to_cpu(prp_list[last_prp]);
468 		dma_pool_free(dev->prp_page_pool, prp_list, prp_dma);
469 		prp_dma = next_prp_dma;
470 	}
471 
472 	if (iod->sg != iod->inline_sg)
473 		kfree(iod->sg);
474 }
475 
476 #ifdef CONFIG_BLK_DEV_INTEGRITY
477 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
478 {
479 	if (be32_to_cpu(pi->ref_tag) == v)
480 		pi->ref_tag = cpu_to_be32(p);
481 }
482 
483 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
484 {
485 	if (be32_to_cpu(pi->ref_tag) == p)
486 		pi->ref_tag = cpu_to_be32(v);
487 }
488 
489 /**
490  * nvme_dif_remap - remaps ref tags to bip seed and physical lba
491  *
492  * The virtual start sector is the one that was originally submitted by the
493  * block layer.	Due to partitioning, MD/DM cloning, etc. the actual physical
494  * start sector may be different. Remap protection information to match the
495  * physical LBA on writes, and back to the original seed on reads.
496  *
497  * Type 0 and 3 do not have a ref tag, so no remapping required.
498  */
499 static void nvme_dif_remap(struct request *req,
500 			void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
501 {
502 	struct nvme_ns *ns = req->rq_disk->private_data;
503 	struct bio_integrity_payload *bip;
504 	struct t10_pi_tuple *pi;
505 	void *p, *pmap;
506 	u32 i, nlb, ts, phys, virt;
507 
508 	if (!ns->pi_type || ns->pi_type == NVME_NS_DPS_PI_TYPE3)
509 		return;
510 
511 	bip = bio_integrity(req->bio);
512 	if (!bip)
513 		return;
514 
515 	pmap = kmap_atomic(bip->bip_vec->bv_page) + bip->bip_vec->bv_offset;
516 
517 	p = pmap;
518 	virt = bip_get_seed(bip);
519 	phys = nvme_block_nr(ns, blk_rq_pos(req));
520 	nlb = (blk_rq_bytes(req) >> ns->lba_shift);
521 	ts = ns->disk->queue->integrity.tuple_size;
522 
523 	for (i = 0; i < nlb; i++, virt++, phys++) {
524 		pi = (struct t10_pi_tuple *)p;
525 		dif_swap(phys, virt, pi);
526 		p += ts;
527 	}
528 	kunmap_atomic(pmap);
529 }
530 #else /* CONFIG_BLK_DEV_INTEGRITY */
531 static void nvme_dif_remap(struct request *req,
532 			void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
533 {
534 }
535 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
536 {
537 }
538 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
539 {
540 }
541 #endif
542 
543 static blk_status_t nvme_setup_prps(struct nvme_dev *dev, struct request *req)
544 {
545 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
546 	struct dma_pool *pool;
547 	int length = blk_rq_payload_bytes(req);
548 	struct scatterlist *sg = iod->sg;
549 	int dma_len = sg_dma_len(sg);
550 	u64 dma_addr = sg_dma_address(sg);
551 	u32 page_size = dev->ctrl.page_size;
552 	int offset = dma_addr & (page_size - 1);
553 	__le64 *prp_list;
554 	__le64 **list = iod_list(req);
555 	dma_addr_t prp_dma;
556 	int nprps, i;
557 
558 	length -= (page_size - offset);
559 	if (length <= 0) {
560 		iod->first_dma = 0;
561 		return BLK_STS_OK;
562 	}
563 
564 	dma_len -= (page_size - offset);
565 	if (dma_len) {
566 		dma_addr += (page_size - offset);
567 	} else {
568 		sg = sg_next(sg);
569 		dma_addr = sg_dma_address(sg);
570 		dma_len = sg_dma_len(sg);
571 	}
572 
573 	if (length <= page_size) {
574 		iod->first_dma = dma_addr;
575 		return BLK_STS_OK;
576 	}
577 
578 	nprps = DIV_ROUND_UP(length, page_size);
579 	if (nprps <= (256 / 8)) {
580 		pool = dev->prp_small_pool;
581 		iod->npages = 0;
582 	} else {
583 		pool = dev->prp_page_pool;
584 		iod->npages = 1;
585 	}
586 
587 	prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
588 	if (!prp_list) {
589 		iod->first_dma = dma_addr;
590 		iod->npages = -1;
591 		return BLK_STS_RESOURCE;
592 	}
593 	list[0] = prp_list;
594 	iod->first_dma = prp_dma;
595 	i = 0;
596 	for (;;) {
597 		if (i == page_size >> 3) {
598 			__le64 *old_prp_list = prp_list;
599 			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
600 			if (!prp_list)
601 				return BLK_STS_RESOURCE;
602 			list[iod->npages++] = prp_list;
603 			prp_list[0] = old_prp_list[i - 1];
604 			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
605 			i = 1;
606 		}
607 		prp_list[i++] = cpu_to_le64(dma_addr);
608 		dma_len -= page_size;
609 		dma_addr += page_size;
610 		length -= page_size;
611 		if (length <= 0)
612 			break;
613 		if (dma_len > 0)
614 			continue;
615 		if (unlikely(dma_len < 0))
616 			goto bad_sgl;
617 		sg = sg_next(sg);
618 		dma_addr = sg_dma_address(sg);
619 		dma_len = sg_dma_len(sg);
620 	}
621 
622 	return BLK_STS_OK;
623 
624  bad_sgl:
625 	if (WARN_ONCE(1, "Invalid SGL for payload:%d nents:%d\n",
626 				blk_rq_payload_bytes(req), iod->nents)) {
627 		for_each_sg(iod->sg, sg, iod->nents, i) {
628 			dma_addr_t phys = sg_phys(sg);
629 			pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d "
630 			       "dma_address:%pad dma_length:%d\n", i, &phys,
631 					sg->offset, sg->length,
632 					&sg_dma_address(sg),
633 					sg_dma_len(sg));
634 		}
635 	}
636 	return BLK_STS_IOERR;
637 
638 }
639 
640 static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
641 		struct nvme_command *cmnd)
642 {
643 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
644 	struct request_queue *q = req->q;
645 	enum dma_data_direction dma_dir = rq_data_dir(req) ?
646 			DMA_TO_DEVICE : DMA_FROM_DEVICE;
647 	blk_status_t ret = BLK_STS_IOERR;
648 
649 	sg_init_table(iod->sg, blk_rq_nr_phys_segments(req));
650 	iod->nents = blk_rq_map_sg(q, req, iod->sg);
651 	if (!iod->nents)
652 		goto out;
653 
654 	ret = BLK_STS_RESOURCE;
655 	if (!dma_map_sg_attrs(dev->dev, iod->sg, iod->nents, dma_dir,
656 				DMA_ATTR_NO_WARN))
657 		goto out;
658 
659 	ret = nvme_setup_prps(dev, req);
660 	if (ret != BLK_STS_OK)
661 		goto out_unmap;
662 
663 	ret = BLK_STS_IOERR;
664 	if (blk_integrity_rq(req)) {
665 		if (blk_rq_count_integrity_sg(q, req->bio) != 1)
666 			goto out_unmap;
667 
668 		sg_init_table(&iod->meta_sg, 1);
669 		if (blk_rq_map_integrity_sg(q, req->bio, &iod->meta_sg) != 1)
670 			goto out_unmap;
671 
672 		if (req_op(req) == REQ_OP_WRITE)
673 			nvme_dif_remap(req, nvme_dif_prep);
674 
675 		if (!dma_map_sg(dev->dev, &iod->meta_sg, 1, dma_dir))
676 			goto out_unmap;
677 	}
678 
679 	cmnd->rw.dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
680 	cmnd->rw.dptr.prp2 = cpu_to_le64(iod->first_dma);
681 	if (blk_integrity_rq(req))
682 		cmnd->rw.metadata = cpu_to_le64(sg_dma_address(&iod->meta_sg));
683 	return BLK_STS_OK;
684 
685 out_unmap:
686 	dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
687 out:
688 	return ret;
689 }
690 
691 static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
692 {
693 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
694 	enum dma_data_direction dma_dir = rq_data_dir(req) ?
695 			DMA_TO_DEVICE : DMA_FROM_DEVICE;
696 
697 	if (iod->nents) {
698 		dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
699 		if (blk_integrity_rq(req)) {
700 			if (req_op(req) == REQ_OP_READ)
701 				nvme_dif_remap(req, nvme_dif_complete);
702 			dma_unmap_sg(dev->dev, &iod->meta_sg, 1, dma_dir);
703 		}
704 	}
705 
706 	nvme_cleanup_cmd(req);
707 	nvme_free_iod(dev, req);
708 }
709 
710 /*
711  * NOTE: ns is NULL when called on the admin queue.
712  */
713 static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
714 			 const struct blk_mq_queue_data *bd)
715 {
716 	struct nvme_ns *ns = hctx->queue->queuedata;
717 	struct nvme_queue *nvmeq = hctx->driver_data;
718 	struct nvme_dev *dev = nvmeq->dev;
719 	struct request *req = bd->rq;
720 	struct nvme_command cmnd;
721 	blk_status_t ret;
722 
723 	ret = nvme_setup_cmd(ns, req, &cmnd);
724 	if (ret)
725 		return ret;
726 
727 	ret = nvme_init_iod(req, dev);
728 	if (ret)
729 		goto out_free_cmd;
730 
731 	if (blk_rq_nr_phys_segments(req)) {
732 		ret = nvme_map_data(dev, req, &cmnd);
733 		if (ret)
734 			goto out_cleanup_iod;
735 	}
736 
737 	blk_mq_start_request(req);
738 
739 	spin_lock_irq(&nvmeq->q_lock);
740 	if (unlikely(nvmeq->cq_vector < 0)) {
741 		ret = BLK_STS_IOERR;
742 		spin_unlock_irq(&nvmeq->q_lock);
743 		goto out_cleanup_iod;
744 	}
745 	__nvme_submit_cmd(nvmeq, &cmnd);
746 	nvme_process_cq(nvmeq);
747 	spin_unlock_irq(&nvmeq->q_lock);
748 	return BLK_STS_OK;
749 out_cleanup_iod:
750 	nvme_free_iod(dev, req);
751 out_free_cmd:
752 	nvme_cleanup_cmd(req);
753 	return ret;
754 }
755 
756 static void nvme_pci_complete_rq(struct request *req)
757 {
758 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
759 
760 	nvme_unmap_data(iod->nvmeq->dev, req);
761 	nvme_complete_rq(req);
762 }
763 
764 /* We read the CQE phase first to check if the rest of the entry is valid */
765 static inline bool nvme_cqe_valid(struct nvme_queue *nvmeq, u16 head,
766 		u16 phase)
767 {
768 	return (le16_to_cpu(nvmeq->cqes[head].status) & 1) == phase;
769 }
770 
771 static inline void nvme_ring_cq_doorbell(struct nvme_queue *nvmeq)
772 {
773 	u16 head = nvmeq->cq_head;
774 
775 	if (likely(nvmeq->cq_vector >= 0)) {
776 		if (nvme_dbbuf_update_and_check_event(head, nvmeq->dbbuf_cq_db,
777 						      nvmeq->dbbuf_cq_ei))
778 			writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
779 	}
780 }
781 
782 static inline void nvme_handle_cqe(struct nvme_queue *nvmeq,
783 		struct nvme_completion *cqe)
784 {
785 	struct request *req;
786 
787 	if (unlikely(cqe->command_id >= nvmeq->q_depth)) {
788 		dev_warn(nvmeq->dev->ctrl.device,
789 			"invalid id %d completed on queue %d\n",
790 			cqe->command_id, le16_to_cpu(cqe->sq_id));
791 		return;
792 	}
793 
794 	/*
795 	 * AEN requests are special as they don't time out and can
796 	 * survive any kind of queue freeze and often don't respond to
797 	 * aborts.  We don't even bother to allocate a struct request
798 	 * for them but rather special case them here.
799 	 */
800 	if (unlikely(nvmeq->qid == 0 &&
801 			cqe->command_id >= NVME_AQ_BLKMQ_DEPTH)) {
802 		nvme_complete_async_event(&nvmeq->dev->ctrl,
803 				cqe->status, &cqe->result);
804 		return;
805 	}
806 
807 	nvmeq->cqe_seen = 1;
808 	req = blk_mq_tag_to_rq(*nvmeq->tags, cqe->command_id);
809 	nvme_end_request(req, cqe->status, cqe->result);
810 }
811 
812 static inline bool nvme_read_cqe(struct nvme_queue *nvmeq,
813 		struct nvme_completion *cqe)
814 {
815 	if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase)) {
816 		*cqe = nvmeq->cqes[nvmeq->cq_head];
817 
818 		if (++nvmeq->cq_head == nvmeq->q_depth) {
819 			nvmeq->cq_head = 0;
820 			nvmeq->cq_phase = !nvmeq->cq_phase;
821 		}
822 		return true;
823 	}
824 	return false;
825 }
826 
827 static void nvme_process_cq(struct nvme_queue *nvmeq)
828 {
829 	struct nvme_completion cqe;
830 	int consumed = 0;
831 
832 	while (nvme_read_cqe(nvmeq, &cqe)) {
833 		nvme_handle_cqe(nvmeq, &cqe);
834 		consumed++;
835 	}
836 
837 	if (consumed)
838 		nvme_ring_cq_doorbell(nvmeq);
839 }
840 
841 static irqreturn_t nvme_irq(int irq, void *data)
842 {
843 	irqreturn_t result;
844 	struct nvme_queue *nvmeq = data;
845 	spin_lock(&nvmeq->q_lock);
846 	nvme_process_cq(nvmeq);
847 	result = nvmeq->cqe_seen ? IRQ_HANDLED : IRQ_NONE;
848 	nvmeq->cqe_seen = 0;
849 	spin_unlock(&nvmeq->q_lock);
850 	return result;
851 }
852 
853 static irqreturn_t nvme_irq_check(int irq, void *data)
854 {
855 	struct nvme_queue *nvmeq = data;
856 	if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase))
857 		return IRQ_WAKE_THREAD;
858 	return IRQ_NONE;
859 }
860 
861 static int __nvme_poll(struct nvme_queue *nvmeq, unsigned int tag)
862 {
863 	struct nvme_completion cqe;
864 	int found = 0, consumed = 0;
865 
866 	if (!nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase))
867 		return 0;
868 
869 	spin_lock_irq(&nvmeq->q_lock);
870 	while (nvme_read_cqe(nvmeq, &cqe)) {
871 		nvme_handle_cqe(nvmeq, &cqe);
872 		consumed++;
873 
874 		if (tag == cqe.command_id) {
875 			found = 1;
876 			break;
877 		}
878        }
879 
880 	if (consumed)
881 		nvme_ring_cq_doorbell(nvmeq);
882 	spin_unlock_irq(&nvmeq->q_lock);
883 
884 	return found;
885 }
886 
887 static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
888 {
889 	struct nvme_queue *nvmeq = hctx->driver_data;
890 
891 	return __nvme_poll(nvmeq, tag);
892 }
893 
894 static void nvme_pci_submit_async_event(struct nvme_ctrl *ctrl, int aer_idx)
895 {
896 	struct nvme_dev *dev = to_nvme_dev(ctrl);
897 	struct nvme_queue *nvmeq = dev->queues[0];
898 	struct nvme_command c;
899 
900 	memset(&c, 0, sizeof(c));
901 	c.common.opcode = nvme_admin_async_event;
902 	c.common.command_id = NVME_AQ_BLKMQ_DEPTH + aer_idx;
903 
904 	spin_lock_irq(&nvmeq->q_lock);
905 	__nvme_submit_cmd(nvmeq, &c);
906 	spin_unlock_irq(&nvmeq->q_lock);
907 }
908 
909 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
910 {
911 	struct nvme_command c;
912 
913 	memset(&c, 0, sizeof(c));
914 	c.delete_queue.opcode = opcode;
915 	c.delete_queue.qid = cpu_to_le16(id);
916 
917 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
918 }
919 
920 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
921 						struct nvme_queue *nvmeq)
922 {
923 	struct nvme_command c;
924 	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
925 
926 	/*
927 	 * Note: we (ab)use the fact the the prp fields survive if no data
928 	 * is attached to the request.
929 	 */
930 	memset(&c, 0, sizeof(c));
931 	c.create_cq.opcode = nvme_admin_create_cq;
932 	c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
933 	c.create_cq.cqid = cpu_to_le16(qid);
934 	c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
935 	c.create_cq.cq_flags = cpu_to_le16(flags);
936 	c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
937 
938 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
939 }
940 
941 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
942 						struct nvme_queue *nvmeq)
943 {
944 	struct nvme_command c;
945 	int flags = NVME_QUEUE_PHYS_CONTIG;
946 
947 	/*
948 	 * Note: we (ab)use the fact the the prp fields survive if no data
949 	 * is attached to the request.
950 	 */
951 	memset(&c, 0, sizeof(c));
952 	c.create_sq.opcode = nvme_admin_create_sq;
953 	c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
954 	c.create_sq.sqid = cpu_to_le16(qid);
955 	c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
956 	c.create_sq.sq_flags = cpu_to_le16(flags);
957 	c.create_sq.cqid = cpu_to_le16(qid);
958 
959 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
960 }
961 
962 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
963 {
964 	return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
965 }
966 
967 static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
968 {
969 	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
970 }
971 
972 static void abort_endio(struct request *req, blk_status_t error)
973 {
974 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
975 	struct nvme_queue *nvmeq = iod->nvmeq;
976 
977 	dev_warn(nvmeq->dev->ctrl.device,
978 		 "Abort status: 0x%x", nvme_req(req)->status);
979 	atomic_inc(&nvmeq->dev->ctrl.abort_limit);
980 	blk_mq_free_request(req);
981 }
982 
983 static bool nvme_should_reset(struct nvme_dev *dev, u32 csts)
984 {
985 
986 	/* If true, indicates loss of adapter communication, possibly by a
987 	 * NVMe Subsystem reset.
988 	 */
989 	bool nssro = dev->subsystem && (csts & NVME_CSTS_NSSRO);
990 
991 	/* If there is a reset ongoing, we shouldn't reset again. */
992 	if (dev->ctrl.state == NVME_CTRL_RESETTING)
993 		return false;
994 
995 	/* We shouldn't reset unless the controller is on fatal error state
996 	 * _or_ if we lost the communication with it.
997 	 */
998 	if (!(csts & NVME_CSTS_CFS) && !nssro)
999 		return false;
1000 
1001 	/* If PCI error recovery process is happening, we cannot reset or
1002 	 * the recovery mechanism will surely fail.
1003 	 */
1004 	if (pci_channel_offline(to_pci_dev(dev->dev)))
1005 		return false;
1006 
1007 	return true;
1008 }
1009 
1010 static void nvme_warn_reset(struct nvme_dev *dev, u32 csts)
1011 {
1012 	/* Read a config register to help see what died. */
1013 	u16 pci_status;
1014 	int result;
1015 
1016 	result = pci_read_config_word(to_pci_dev(dev->dev), PCI_STATUS,
1017 				      &pci_status);
1018 	if (result == PCIBIOS_SUCCESSFUL)
1019 		dev_warn(dev->ctrl.device,
1020 			 "controller is down; will reset: CSTS=0x%x, PCI_STATUS=0x%hx\n",
1021 			 csts, pci_status);
1022 	else
1023 		dev_warn(dev->ctrl.device,
1024 			 "controller is down; will reset: CSTS=0x%x, PCI_STATUS read failed (%d)\n",
1025 			 csts, result);
1026 }
1027 
1028 static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
1029 {
1030 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
1031 	struct nvme_queue *nvmeq = iod->nvmeq;
1032 	struct nvme_dev *dev = nvmeq->dev;
1033 	struct request *abort_req;
1034 	struct nvme_command cmd;
1035 	u32 csts = readl(dev->bar + NVME_REG_CSTS);
1036 
1037 	/*
1038 	 * Reset immediately if the controller is failed
1039 	 */
1040 	if (nvme_should_reset(dev, csts)) {
1041 		nvme_warn_reset(dev, csts);
1042 		nvme_dev_disable(dev, false);
1043 		nvme_reset_ctrl(&dev->ctrl);
1044 		return BLK_EH_HANDLED;
1045 	}
1046 
1047 	/*
1048 	 * Did we miss an interrupt?
1049 	 */
1050 	if (__nvme_poll(nvmeq, req->tag)) {
1051 		dev_warn(dev->ctrl.device,
1052 			 "I/O %d QID %d timeout, completion polled\n",
1053 			 req->tag, nvmeq->qid);
1054 		return BLK_EH_HANDLED;
1055 	}
1056 
1057 	/*
1058 	 * Shutdown immediately if controller times out while starting. The
1059 	 * reset work will see the pci device disabled when it gets the forced
1060 	 * cancellation error. All outstanding requests are completed on
1061 	 * shutdown, so we return BLK_EH_HANDLED.
1062 	 */
1063 	if (dev->ctrl.state == NVME_CTRL_RESETTING) {
1064 		dev_warn(dev->ctrl.device,
1065 			 "I/O %d QID %d timeout, disable controller\n",
1066 			 req->tag, nvmeq->qid);
1067 		nvme_dev_disable(dev, false);
1068 		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
1069 		return BLK_EH_HANDLED;
1070 	}
1071 
1072 	/*
1073  	 * Shutdown the controller immediately and schedule a reset if the
1074  	 * command was already aborted once before and still hasn't been
1075  	 * returned to the driver, or if this is the admin queue.
1076 	 */
1077 	if (!nvmeq->qid || iod->aborted) {
1078 		dev_warn(dev->ctrl.device,
1079 			 "I/O %d QID %d timeout, reset controller\n",
1080 			 req->tag, nvmeq->qid);
1081 		nvme_dev_disable(dev, false);
1082 		nvme_reset_ctrl(&dev->ctrl);
1083 
1084 		/*
1085 		 * Mark the request as handled, since the inline shutdown
1086 		 * forces all outstanding requests to complete.
1087 		 */
1088 		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
1089 		return BLK_EH_HANDLED;
1090 	}
1091 
1092 	if (atomic_dec_return(&dev->ctrl.abort_limit) < 0) {
1093 		atomic_inc(&dev->ctrl.abort_limit);
1094 		return BLK_EH_RESET_TIMER;
1095 	}
1096 	iod->aborted = 1;
1097 
1098 	memset(&cmd, 0, sizeof(cmd));
1099 	cmd.abort.opcode = nvme_admin_abort_cmd;
1100 	cmd.abort.cid = req->tag;
1101 	cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
1102 
1103 	dev_warn(nvmeq->dev->ctrl.device,
1104 		"I/O %d QID %d timeout, aborting\n",
1105 		 req->tag, nvmeq->qid);
1106 
1107 	abort_req = nvme_alloc_request(dev->ctrl.admin_q, &cmd,
1108 			BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
1109 	if (IS_ERR(abort_req)) {
1110 		atomic_inc(&dev->ctrl.abort_limit);
1111 		return BLK_EH_RESET_TIMER;
1112 	}
1113 
1114 	abort_req->timeout = ADMIN_TIMEOUT;
1115 	abort_req->end_io_data = NULL;
1116 	blk_execute_rq_nowait(abort_req->q, NULL, abort_req, 0, abort_endio);
1117 
1118 	/*
1119 	 * The aborted req will be completed on receiving the abort req.
1120 	 * We enable the timer again. If hit twice, it'll cause a device reset,
1121 	 * as the device then is in a faulty state.
1122 	 */
1123 	return BLK_EH_RESET_TIMER;
1124 }
1125 
1126 static void nvme_free_queue(struct nvme_queue *nvmeq)
1127 {
1128 	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
1129 				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
1130 	if (nvmeq->sq_cmds)
1131 		dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
1132 					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
1133 	kfree(nvmeq);
1134 }
1135 
1136 static void nvme_free_queues(struct nvme_dev *dev, int lowest)
1137 {
1138 	int i;
1139 
1140 	for (i = dev->ctrl.queue_count - 1; i >= lowest; i--) {
1141 		struct nvme_queue *nvmeq = dev->queues[i];
1142 		dev->ctrl.queue_count--;
1143 		dev->queues[i] = NULL;
1144 		nvme_free_queue(nvmeq);
1145 	}
1146 }
1147 
1148 /**
1149  * nvme_suspend_queue - put queue into suspended state
1150  * @nvmeq - queue to suspend
1151  */
1152 static int nvme_suspend_queue(struct nvme_queue *nvmeq)
1153 {
1154 	int vector;
1155 
1156 	spin_lock_irq(&nvmeq->q_lock);
1157 	if (nvmeq->cq_vector == -1) {
1158 		spin_unlock_irq(&nvmeq->q_lock);
1159 		return 1;
1160 	}
1161 	vector = nvmeq->cq_vector;
1162 	nvmeq->dev->online_queues--;
1163 	nvmeq->cq_vector = -1;
1164 	spin_unlock_irq(&nvmeq->q_lock);
1165 
1166 	if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
1167 		blk_mq_quiesce_queue(nvmeq->dev->ctrl.admin_q);
1168 
1169 	pci_free_irq(to_pci_dev(nvmeq->dev->dev), vector, nvmeq);
1170 
1171 	return 0;
1172 }
1173 
1174 static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
1175 {
1176 	struct nvme_queue *nvmeq = dev->queues[0];
1177 
1178 	if (!nvmeq)
1179 		return;
1180 	if (nvme_suspend_queue(nvmeq))
1181 		return;
1182 
1183 	if (shutdown)
1184 		nvme_shutdown_ctrl(&dev->ctrl);
1185 	else
1186 		nvme_disable_ctrl(&dev->ctrl, dev->ctrl.cap);
1187 
1188 	spin_lock_irq(&nvmeq->q_lock);
1189 	nvme_process_cq(nvmeq);
1190 	spin_unlock_irq(&nvmeq->q_lock);
1191 }
1192 
1193 static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues,
1194 				int entry_size)
1195 {
1196 	int q_depth = dev->q_depth;
1197 	unsigned q_size_aligned = roundup(q_depth * entry_size,
1198 					  dev->ctrl.page_size);
1199 
1200 	if (q_size_aligned * nr_io_queues > dev->cmb_size) {
1201 		u64 mem_per_q = div_u64(dev->cmb_size, nr_io_queues);
1202 		mem_per_q = round_down(mem_per_q, dev->ctrl.page_size);
1203 		q_depth = div_u64(mem_per_q, entry_size);
1204 
1205 		/*
1206 		 * Ensure the reduced q_depth is above some threshold where it
1207 		 * would be better to map queues in system memory with the
1208 		 * original depth
1209 		 */
1210 		if (q_depth < 64)
1211 			return -ENOMEM;
1212 	}
1213 
1214 	return q_depth;
1215 }
1216 
1217 static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
1218 				int qid, int depth)
1219 {
1220 	if (qid && dev->cmb && use_cmb_sqes && NVME_CMB_SQS(dev->cmbsz)) {
1221 		unsigned offset = (qid - 1) * roundup(SQ_SIZE(depth),
1222 						      dev->ctrl.page_size);
1223 		nvmeq->sq_dma_addr = dev->cmb_dma_addr + offset;
1224 		nvmeq->sq_cmds_io = dev->cmb + offset;
1225 	} else {
1226 		nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(depth),
1227 					&nvmeq->sq_dma_addr, GFP_KERNEL);
1228 		if (!nvmeq->sq_cmds)
1229 			return -ENOMEM;
1230 	}
1231 
1232 	return 0;
1233 }
1234 
1235 static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
1236 							int depth, int node)
1237 {
1238 	struct nvme_queue *nvmeq = kzalloc_node(sizeof(*nvmeq), GFP_KERNEL,
1239 							node);
1240 	if (!nvmeq)
1241 		return NULL;
1242 
1243 	nvmeq->cqes = dma_zalloc_coherent(dev->dev, CQ_SIZE(depth),
1244 					  &nvmeq->cq_dma_addr, GFP_KERNEL);
1245 	if (!nvmeq->cqes)
1246 		goto free_nvmeq;
1247 
1248 	if (nvme_alloc_sq_cmds(dev, nvmeq, qid, depth))
1249 		goto free_cqdma;
1250 
1251 	nvmeq->q_dmadev = dev->dev;
1252 	nvmeq->dev = dev;
1253 	spin_lock_init(&nvmeq->q_lock);
1254 	nvmeq->cq_head = 0;
1255 	nvmeq->cq_phase = 1;
1256 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1257 	nvmeq->q_depth = depth;
1258 	nvmeq->qid = qid;
1259 	nvmeq->cq_vector = -1;
1260 	dev->queues[qid] = nvmeq;
1261 	dev->ctrl.queue_count++;
1262 
1263 	return nvmeq;
1264 
1265  free_cqdma:
1266 	dma_free_coherent(dev->dev, CQ_SIZE(depth), (void *)nvmeq->cqes,
1267 							nvmeq->cq_dma_addr);
1268  free_nvmeq:
1269 	kfree(nvmeq);
1270 	return NULL;
1271 }
1272 
1273 static int queue_request_irq(struct nvme_queue *nvmeq)
1274 {
1275 	struct pci_dev *pdev = to_pci_dev(nvmeq->dev->dev);
1276 	int nr = nvmeq->dev->ctrl.instance;
1277 
1278 	if (use_threaded_interrupts) {
1279 		return pci_request_irq(pdev, nvmeq->cq_vector, nvme_irq_check,
1280 				nvme_irq, nvmeq, "nvme%dq%d", nr, nvmeq->qid);
1281 	} else {
1282 		return pci_request_irq(pdev, nvmeq->cq_vector, nvme_irq,
1283 				NULL, nvmeq, "nvme%dq%d", nr, nvmeq->qid);
1284 	}
1285 }
1286 
1287 static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
1288 {
1289 	struct nvme_dev *dev = nvmeq->dev;
1290 
1291 	spin_lock_irq(&nvmeq->q_lock);
1292 	nvmeq->sq_tail = 0;
1293 	nvmeq->cq_head = 0;
1294 	nvmeq->cq_phase = 1;
1295 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1296 	memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth));
1297 	nvme_dbbuf_init(dev, nvmeq, qid);
1298 	dev->online_queues++;
1299 	spin_unlock_irq(&nvmeq->q_lock);
1300 }
1301 
1302 static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
1303 {
1304 	struct nvme_dev *dev = nvmeq->dev;
1305 	int result;
1306 
1307 	nvmeq->cq_vector = qid - 1;
1308 	result = adapter_alloc_cq(dev, qid, nvmeq);
1309 	if (result < 0)
1310 		return result;
1311 
1312 	result = adapter_alloc_sq(dev, qid, nvmeq);
1313 	if (result < 0)
1314 		goto release_cq;
1315 
1316 	nvme_init_queue(nvmeq, qid);
1317 	result = queue_request_irq(nvmeq);
1318 	if (result < 0)
1319 		goto release_sq;
1320 
1321 	return result;
1322 
1323  release_sq:
1324 	adapter_delete_sq(dev, qid);
1325  release_cq:
1326 	adapter_delete_cq(dev, qid);
1327 	return result;
1328 }
1329 
1330 static const struct blk_mq_ops nvme_mq_admin_ops = {
1331 	.queue_rq	= nvme_queue_rq,
1332 	.complete	= nvme_pci_complete_rq,
1333 	.init_hctx	= nvme_admin_init_hctx,
1334 	.exit_hctx      = nvme_admin_exit_hctx,
1335 	.init_request	= nvme_init_request,
1336 	.timeout	= nvme_timeout,
1337 };
1338 
1339 static const struct blk_mq_ops nvme_mq_ops = {
1340 	.queue_rq	= nvme_queue_rq,
1341 	.complete	= nvme_pci_complete_rq,
1342 	.init_hctx	= nvme_init_hctx,
1343 	.init_request	= nvme_init_request,
1344 	.map_queues	= nvme_pci_map_queues,
1345 	.timeout	= nvme_timeout,
1346 	.poll		= nvme_poll,
1347 };
1348 
1349 static void nvme_dev_remove_admin(struct nvme_dev *dev)
1350 {
1351 	if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q)) {
1352 		/*
1353 		 * If the controller was reset during removal, it's possible
1354 		 * user requests may be waiting on a stopped queue. Start the
1355 		 * queue to flush these to completion.
1356 		 */
1357 		blk_mq_unquiesce_queue(dev->ctrl.admin_q);
1358 		blk_cleanup_queue(dev->ctrl.admin_q);
1359 		blk_mq_free_tag_set(&dev->admin_tagset);
1360 	}
1361 }
1362 
1363 static int nvme_alloc_admin_tags(struct nvme_dev *dev)
1364 {
1365 	if (!dev->ctrl.admin_q) {
1366 		dev->admin_tagset.ops = &nvme_mq_admin_ops;
1367 		dev->admin_tagset.nr_hw_queues = 1;
1368 
1369 		/*
1370 		 * Subtract one to leave an empty queue entry for 'Full Queue'
1371 		 * condition. See NVM-Express 1.2 specification, section 4.1.2.
1372 		 */
1373 		dev->admin_tagset.queue_depth = NVME_AQ_BLKMQ_DEPTH - 1;
1374 		dev->admin_tagset.timeout = ADMIN_TIMEOUT;
1375 		dev->admin_tagset.numa_node = dev_to_node(dev->dev);
1376 		dev->admin_tagset.cmd_size = nvme_cmd_size(dev);
1377 		dev->admin_tagset.flags = BLK_MQ_F_NO_SCHED;
1378 		dev->admin_tagset.driver_data = dev;
1379 
1380 		if (blk_mq_alloc_tag_set(&dev->admin_tagset))
1381 			return -ENOMEM;
1382 		dev->ctrl.admin_tagset = &dev->admin_tagset;
1383 
1384 		dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
1385 		if (IS_ERR(dev->ctrl.admin_q)) {
1386 			blk_mq_free_tag_set(&dev->admin_tagset);
1387 			return -ENOMEM;
1388 		}
1389 		if (!blk_get_queue(dev->ctrl.admin_q)) {
1390 			nvme_dev_remove_admin(dev);
1391 			dev->ctrl.admin_q = NULL;
1392 			return -ENODEV;
1393 		}
1394 	} else
1395 		blk_mq_unquiesce_queue(dev->ctrl.admin_q);
1396 
1397 	return 0;
1398 }
1399 
1400 static unsigned long db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
1401 {
1402 	return NVME_REG_DBS + ((nr_io_queues + 1) * 8 * dev->db_stride);
1403 }
1404 
1405 static int nvme_remap_bar(struct nvme_dev *dev, unsigned long size)
1406 {
1407 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1408 
1409 	if (size <= dev->bar_mapped_size)
1410 		return 0;
1411 	if (size > pci_resource_len(pdev, 0))
1412 		return -ENOMEM;
1413 	if (dev->bar)
1414 		iounmap(dev->bar);
1415 	dev->bar = ioremap(pci_resource_start(pdev, 0), size);
1416 	if (!dev->bar) {
1417 		dev->bar_mapped_size = 0;
1418 		return -ENOMEM;
1419 	}
1420 	dev->bar_mapped_size = size;
1421 	dev->dbs = dev->bar + NVME_REG_DBS;
1422 
1423 	return 0;
1424 }
1425 
1426 static int nvme_pci_configure_admin_queue(struct nvme_dev *dev)
1427 {
1428 	int result;
1429 	u32 aqa;
1430 	struct nvme_queue *nvmeq;
1431 
1432 	result = nvme_remap_bar(dev, db_bar_size(dev, 0));
1433 	if (result < 0)
1434 		return result;
1435 
1436 	dev->subsystem = readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 1, 0) ?
1437 				NVME_CAP_NSSRC(dev->ctrl.cap) : 0;
1438 
1439 	if (dev->subsystem &&
1440 	    (readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_NSSRO))
1441 		writel(NVME_CSTS_NSSRO, dev->bar + NVME_REG_CSTS);
1442 
1443 	result = nvme_disable_ctrl(&dev->ctrl, dev->ctrl.cap);
1444 	if (result < 0)
1445 		return result;
1446 
1447 	nvmeq = dev->queues[0];
1448 	if (!nvmeq) {
1449 		nvmeq = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH,
1450 					dev_to_node(dev->dev));
1451 		if (!nvmeq)
1452 			return -ENOMEM;
1453 	}
1454 
1455 	aqa = nvmeq->q_depth - 1;
1456 	aqa |= aqa << 16;
1457 
1458 	writel(aqa, dev->bar + NVME_REG_AQA);
1459 	lo_hi_writeq(nvmeq->sq_dma_addr, dev->bar + NVME_REG_ASQ);
1460 	lo_hi_writeq(nvmeq->cq_dma_addr, dev->bar + NVME_REG_ACQ);
1461 
1462 	result = nvme_enable_ctrl(&dev->ctrl, dev->ctrl.cap);
1463 	if (result)
1464 		return result;
1465 
1466 	nvmeq->cq_vector = 0;
1467 	nvme_init_queue(nvmeq, 0);
1468 	result = queue_request_irq(nvmeq);
1469 	if (result) {
1470 		nvmeq->cq_vector = -1;
1471 		return result;
1472 	}
1473 
1474 	return result;
1475 }
1476 
1477 static int nvme_create_io_queues(struct nvme_dev *dev)
1478 {
1479 	unsigned i, max;
1480 	int ret = 0;
1481 
1482 	for (i = dev->ctrl.queue_count; i <= dev->max_qid; i++) {
1483 		/* vector == qid - 1, match nvme_create_queue */
1484 		if (!nvme_alloc_queue(dev, i, dev->q_depth,
1485 		     pci_irq_get_node(to_pci_dev(dev->dev), i - 1))) {
1486 			ret = -ENOMEM;
1487 			break;
1488 		}
1489 	}
1490 
1491 	max = min(dev->max_qid, dev->ctrl.queue_count - 1);
1492 	for (i = dev->online_queues; i <= max; i++) {
1493 		ret = nvme_create_queue(dev->queues[i], i);
1494 		if (ret)
1495 			break;
1496 	}
1497 
1498 	/*
1499 	 * Ignore failing Create SQ/CQ commands, we can continue with less
1500 	 * than the desired aount of queues, and even a controller without
1501 	 * I/O queues an still be used to issue admin commands.  This might
1502 	 * be useful to upgrade a buggy firmware for example.
1503 	 */
1504 	return ret >= 0 ? 0 : ret;
1505 }
1506 
1507 static ssize_t nvme_cmb_show(struct device *dev,
1508 			     struct device_attribute *attr,
1509 			     char *buf)
1510 {
1511 	struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
1512 
1513 	return scnprintf(buf, PAGE_SIZE, "cmbloc : x%08x\ncmbsz  : x%08x\n",
1514 		       ndev->cmbloc, ndev->cmbsz);
1515 }
1516 static DEVICE_ATTR(cmb, S_IRUGO, nvme_cmb_show, NULL);
1517 
1518 static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
1519 {
1520 	u64 szu, size, offset;
1521 	resource_size_t bar_size;
1522 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1523 	void __iomem *cmb;
1524 	dma_addr_t dma_addr;
1525 
1526 	dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
1527 	if (!(NVME_CMB_SZ(dev->cmbsz)))
1528 		return NULL;
1529 	dev->cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
1530 
1531 	if (!use_cmb_sqes)
1532 		return NULL;
1533 
1534 	szu = (u64)1 << (12 + 4 * NVME_CMB_SZU(dev->cmbsz));
1535 	size = szu * NVME_CMB_SZ(dev->cmbsz);
1536 	offset = szu * NVME_CMB_OFST(dev->cmbloc);
1537 	bar_size = pci_resource_len(pdev, NVME_CMB_BIR(dev->cmbloc));
1538 
1539 	if (offset > bar_size)
1540 		return NULL;
1541 
1542 	/*
1543 	 * Controllers may support a CMB size larger than their BAR,
1544 	 * for example, due to being behind a bridge. Reduce the CMB to
1545 	 * the reported size of the BAR
1546 	 */
1547 	if (size > bar_size - offset)
1548 		size = bar_size - offset;
1549 
1550 	dma_addr = pci_resource_start(pdev, NVME_CMB_BIR(dev->cmbloc)) + offset;
1551 	cmb = ioremap_wc(dma_addr, size);
1552 	if (!cmb)
1553 		return NULL;
1554 
1555 	dev->cmb_dma_addr = dma_addr;
1556 	dev->cmb_size = size;
1557 	return cmb;
1558 }
1559 
1560 static inline void nvme_release_cmb(struct nvme_dev *dev)
1561 {
1562 	if (dev->cmb) {
1563 		iounmap(dev->cmb);
1564 		dev->cmb = NULL;
1565 		sysfs_remove_file_from_group(&dev->ctrl.device->kobj,
1566 					     &dev_attr_cmb.attr, NULL);
1567 		dev->cmbsz = 0;
1568 	}
1569 }
1570 
1571 static int nvme_set_host_mem(struct nvme_dev *dev, u32 bits)
1572 {
1573 	u64 dma_addr = dev->host_mem_descs_dma;
1574 	struct nvme_command c;
1575 	int ret;
1576 
1577 	memset(&c, 0, sizeof(c));
1578 	c.features.opcode	= nvme_admin_set_features;
1579 	c.features.fid		= cpu_to_le32(NVME_FEAT_HOST_MEM_BUF);
1580 	c.features.dword11	= cpu_to_le32(bits);
1581 	c.features.dword12	= cpu_to_le32(dev->host_mem_size >>
1582 					      ilog2(dev->ctrl.page_size));
1583 	c.features.dword13	= cpu_to_le32(lower_32_bits(dma_addr));
1584 	c.features.dword14	= cpu_to_le32(upper_32_bits(dma_addr));
1585 	c.features.dword15	= cpu_to_le32(dev->nr_host_mem_descs);
1586 
1587 	ret = nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1588 	if (ret) {
1589 		dev_warn(dev->ctrl.device,
1590 			 "failed to set host mem (err %d, flags %#x).\n",
1591 			 ret, bits);
1592 	}
1593 	return ret;
1594 }
1595 
1596 static void nvme_free_host_mem(struct nvme_dev *dev)
1597 {
1598 	int i;
1599 
1600 	for (i = 0; i < dev->nr_host_mem_descs; i++) {
1601 		struct nvme_host_mem_buf_desc *desc = &dev->host_mem_descs[i];
1602 		size_t size = le32_to_cpu(desc->size) * dev->ctrl.page_size;
1603 
1604 		dma_free_coherent(dev->dev, size, dev->host_mem_desc_bufs[i],
1605 				le64_to_cpu(desc->addr));
1606 	}
1607 
1608 	kfree(dev->host_mem_desc_bufs);
1609 	dev->host_mem_desc_bufs = NULL;
1610 	dma_free_coherent(dev->dev,
1611 			dev->nr_host_mem_descs * sizeof(*dev->host_mem_descs),
1612 			dev->host_mem_descs, dev->host_mem_descs_dma);
1613 	dev->host_mem_descs = NULL;
1614 }
1615 
1616 static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred,
1617 		u32 chunk_size)
1618 {
1619 	struct nvme_host_mem_buf_desc *descs;
1620 	u32 max_entries, len;
1621 	dma_addr_t descs_dma;
1622 	int i = 0;
1623 	void **bufs;
1624 	u64 size = 0, tmp;
1625 
1626 	tmp = (preferred + chunk_size - 1);
1627 	do_div(tmp, chunk_size);
1628 	max_entries = tmp;
1629 
1630 	if (dev->ctrl.hmmaxd && dev->ctrl.hmmaxd < max_entries)
1631 		max_entries = dev->ctrl.hmmaxd;
1632 
1633 	descs = dma_zalloc_coherent(dev->dev, max_entries * sizeof(*descs),
1634 			&descs_dma, GFP_KERNEL);
1635 	if (!descs)
1636 		goto out;
1637 
1638 	bufs = kcalloc(max_entries, sizeof(*bufs), GFP_KERNEL);
1639 	if (!bufs)
1640 		goto out_free_descs;
1641 
1642 	for (size = 0; size < preferred; size += len) {
1643 		dma_addr_t dma_addr;
1644 
1645 		len = min_t(u64, chunk_size, preferred - size);
1646 		bufs[i] = dma_alloc_attrs(dev->dev, len, &dma_addr, GFP_KERNEL,
1647 				DMA_ATTR_NO_KERNEL_MAPPING | DMA_ATTR_NO_WARN);
1648 		if (!bufs[i])
1649 			break;
1650 
1651 		descs[i].addr = cpu_to_le64(dma_addr);
1652 		descs[i].size = cpu_to_le32(len / dev->ctrl.page_size);
1653 		i++;
1654 	}
1655 
1656 	if (!size)
1657 		goto out_free_bufs;
1658 
1659 	dev->nr_host_mem_descs = i;
1660 	dev->host_mem_size = size;
1661 	dev->host_mem_descs = descs;
1662 	dev->host_mem_descs_dma = descs_dma;
1663 	dev->host_mem_desc_bufs = bufs;
1664 	return 0;
1665 
1666 out_free_bufs:
1667 	while (--i >= 0) {
1668 		size_t size = le32_to_cpu(descs[i].size) * dev->ctrl.page_size;
1669 
1670 		dma_free_coherent(dev->dev, size, bufs[i],
1671 				le64_to_cpu(descs[i].addr));
1672 	}
1673 
1674 	kfree(bufs);
1675 out_free_descs:
1676 	dma_free_coherent(dev->dev, max_entries * sizeof(*descs), descs,
1677 			descs_dma);
1678 out:
1679 	dev->host_mem_descs = NULL;
1680 	return -ENOMEM;
1681 }
1682 
1683 static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred)
1684 {
1685 	u32 chunk_size;
1686 
1687 	/* start big and work our way down */
1688 	for (chunk_size = min_t(u64, preferred, PAGE_SIZE * MAX_ORDER_NR_PAGES);
1689 	     chunk_size >= max_t(u32, dev->ctrl.hmminds * 4096, PAGE_SIZE * 2);
1690 	     chunk_size /= 2) {
1691 		if (!__nvme_alloc_host_mem(dev, preferred, chunk_size)) {
1692 			if (!min || dev->host_mem_size >= min)
1693 				return 0;
1694 			nvme_free_host_mem(dev);
1695 		}
1696 	}
1697 
1698 	return -ENOMEM;
1699 }
1700 
1701 static int nvme_setup_host_mem(struct nvme_dev *dev)
1702 {
1703 	u64 max = (u64)max_host_mem_size_mb * SZ_1M;
1704 	u64 preferred = (u64)dev->ctrl.hmpre * 4096;
1705 	u64 min = (u64)dev->ctrl.hmmin * 4096;
1706 	u32 enable_bits = NVME_HOST_MEM_ENABLE;
1707 	int ret = 0;
1708 
1709 	preferred = min(preferred, max);
1710 	if (min > max) {
1711 		dev_warn(dev->ctrl.device,
1712 			"min host memory (%lld MiB) above limit (%d MiB).\n",
1713 			min >> ilog2(SZ_1M), max_host_mem_size_mb);
1714 		nvme_free_host_mem(dev);
1715 		return 0;
1716 	}
1717 
1718 	/*
1719 	 * If we already have a buffer allocated check if we can reuse it.
1720 	 */
1721 	if (dev->host_mem_descs) {
1722 		if (dev->host_mem_size >= min)
1723 			enable_bits |= NVME_HOST_MEM_RETURN;
1724 		else
1725 			nvme_free_host_mem(dev);
1726 	}
1727 
1728 	if (!dev->host_mem_descs) {
1729 		if (nvme_alloc_host_mem(dev, min, preferred)) {
1730 			dev_warn(dev->ctrl.device,
1731 				"failed to allocate host memory buffer.\n");
1732 			return 0; /* controller must work without HMB */
1733 		}
1734 
1735 		dev_info(dev->ctrl.device,
1736 			"allocated %lld MiB host memory buffer.\n",
1737 			dev->host_mem_size >> ilog2(SZ_1M));
1738 	}
1739 
1740 	ret = nvme_set_host_mem(dev, enable_bits);
1741 	if (ret)
1742 		nvme_free_host_mem(dev);
1743 	return ret;
1744 }
1745 
1746 static int nvme_setup_io_queues(struct nvme_dev *dev)
1747 {
1748 	struct nvme_queue *adminq = dev->queues[0];
1749 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1750 	int result, nr_io_queues;
1751 	unsigned long size;
1752 
1753 	nr_io_queues = num_present_cpus();
1754 	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
1755 	if (result < 0)
1756 		return result;
1757 
1758 	if (nr_io_queues == 0)
1759 		return 0;
1760 
1761 	if (dev->cmb && NVME_CMB_SQS(dev->cmbsz)) {
1762 		result = nvme_cmb_qdepth(dev, nr_io_queues,
1763 				sizeof(struct nvme_command));
1764 		if (result > 0)
1765 			dev->q_depth = result;
1766 		else
1767 			nvme_release_cmb(dev);
1768 	}
1769 
1770 	do {
1771 		size = db_bar_size(dev, nr_io_queues);
1772 		result = nvme_remap_bar(dev, size);
1773 		if (!result)
1774 			break;
1775 		if (!--nr_io_queues)
1776 			return -ENOMEM;
1777 	} while (1);
1778 	adminq->q_db = dev->dbs;
1779 
1780 	/* Deregister the admin queue's interrupt */
1781 	pci_free_irq(pdev, 0, adminq);
1782 
1783 	/*
1784 	 * If we enable msix early due to not intx, disable it again before
1785 	 * setting up the full range we need.
1786 	 */
1787 	pci_free_irq_vectors(pdev);
1788 	nr_io_queues = pci_alloc_irq_vectors(pdev, 1, nr_io_queues,
1789 			PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY);
1790 	if (nr_io_queues <= 0)
1791 		return -EIO;
1792 	dev->max_qid = nr_io_queues;
1793 
1794 	/*
1795 	 * Should investigate if there's a performance win from allocating
1796 	 * more queues than interrupt vectors; it might allow the submission
1797 	 * path to scale better, even if the receive path is limited by the
1798 	 * number of interrupts.
1799 	 */
1800 
1801 	result = queue_request_irq(adminq);
1802 	if (result) {
1803 		adminq->cq_vector = -1;
1804 		return result;
1805 	}
1806 	return nvme_create_io_queues(dev);
1807 }
1808 
1809 static void nvme_del_queue_end(struct request *req, blk_status_t error)
1810 {
1811 	struct nvme_queue *nvmeq = req->end_io_data;
1812 
1813 	blk_mq_free_request(req);
1814 	complete(&nvmeq->dev->ioq_wait);
1815 }
1816 
1817 static void nvme_del_cq_end(struct request *req, blk_status_t error)
1818 {
1819 	struct nvme_queue *nvmeq = req->end_io_data;
1820 
1821 	if (!error) {
1822 		unsigned long flags;
1823 
1824 		/*
1825 		 * We might be called with the AQ q_lock held
1826 		 * and the I/O queue q_lock should always
1827 		 * nest inside the AQ one.
1828 		 */
1829 		spin_lock_irqsave_nested(&nvmeq->q_lock, flags,
1830 					SINGLE_DEPTH_NESTING);
1831 		nvme_process_cq(nvmeq);
1832 		spin_unlock_irqrestore(&nvmeq->q_lock, flags);
1833 	}
1834 
1835 	nvme_del_queue_end(req, error);
1836 }
1837 
1838 static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
1839 {
1840 	struct request_queue *q = nvmeq->dev->ctrl.admin_q;
1841 	struct request *req;
1842 	struct nvme_command cmd;
1843 
1844 	memset(&cmd, 0, sizeof(cmd));
1845 	cmd.delete_queue.opcode = opcode;
1846 	cmd.delete_queue.qid = cpu_to_le16(nvmeq->qid);
1847 
1848 	req = nvme_alloc_request(q, &cmd, BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
1849 	if (IS_ERR(req))
1850 		return PTR_ERR(req);
1851 
1852 	req->timeout = ADMIN_TIMEOUT;
1853 	req->end_io_data = nvmeq;
1854 
1855 	blk_execute_rq_nowait(q, NULL, req, false,
1856 			opcode == nvme_admin_delete_cq ?
1857 				nvme_del_cq_end : nvme_del_queue_end);
1858 	return 0;
1859 }
1860 
1861 static void nvme_disable_io_queues(struct nvme_dev *dev, int queues)
1862 {
1863 	int pass;
1864 	unsigned long timeout;
1865 	u8 opcode = nvme_admin_delete_sq;
1866 
1867 	for (pass = 0; pass < 2; pass++) {
1868 		int sent = 0, i = queues;
1869 
1870 		reinit_completion(&dev->ioq_wait);
1871  retry:
1872 		timeout = ADMIN_TIMEOUT;
1873 		for (; i > 0; i--, sent++)
1874 			if (nvme_delete_queue(dev->queues[i], opcode))
1875 				break;
1876 
1877 		while (sent--) {
1878 			timeout = wait_for_completion_io_timeout(&dev->ioq_wait, timeout);
1879 			if (timeout == 0)
1880 				return;
1881 			if (i)
1882 				goto retry;
1883 		}
1884 		opcode = nvme_admin_delete_cq;
1885 	}
1886 }
1887 
1888 /*
1889  * Return: error value if an error occurred setting up the queues or calling
1890  * Identify Device.  0 if these succeeded, even if adding some of the
1891  * namespaces failed.  At the moment, these failures are silent.  TBD which
1892  * failures should be reported.
1893  */
1894 static int nvme_dev_add(struct nvme_dev *dev)
1895 {
1896 	if (!dev->ctrl.tagset) {
1897 		dev->tagset.ops = &nvme_mq_ops;
1898 		dev->tagset.nr_hw_queues = dev->online_queues - 1;
1899 		dev->tagset.timeout = NVME_IO_TIMEOUT;
1900 		dev->tagset.numa_node = dev_to_node(dev->dev);
1901 		dev->tagset.queue_depth =
1902 				min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH) - 1;
1903 		dev->tagset.cmd_size = nvme_cmd_size(dev);
1904 		dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
1905 		dev->tagset.driver_data = dev;
1906 
1907 		if (blk_mq_alloc_tag_set(&dev->tagset))
1908 			return 0;
1909 		dev->ctrl.tagset = &dev->tagset;
1910 
1911 		nvme_dbbuf_set(dev);
1912 	} else {
1913 		blk_mq_update_nr_hw_queues(&dev->tagset, dev->online_queues - 1);
1914 
1915 		/* Free previously allocated queues that are no longer usable */
1916 		nvme_free_queues(dev, dev->online_queues);
1917 	}
1918 
1919 	return 0;
1920 }
1921 
1922 static int nvme_pci_enable(struct nvme_dev *dev)
1923 {
1924 	int result = -ENOMEM;
1925 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1926 
1927 	if (pci_enable_device_mem(pdev))
1928 		return result;
1929 
1930 	pci_set_master(pdev);
1931 
1932 	if (dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(64)) &&
1933 	    dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(32)))
1934 		goto disable;
1935 
1936 	if (readl(dev->bar + NVME_REG_CSTS) == -1) {
1937 		result = -ENODEV;
1938 		goto disable;
1939 	}
1940 
1941 	/*
1942 	 * Some devices and/or platforms don't advertise or work with INTx
1943 	 * interrupts. Pre-enable a single MSIX or MSI vec for setup. We'll
1944 	 * adjust this later.
1945 	 */
1946 	result = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
1947 	if (result < 0)
1948 		return result;
1949 
1950 	dev->ctrl.cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
1951 
1952 	dev->q_depth = min_t(int, NVME_CAP_MQES(dev->ctrl.cap) + 1,
1953 				io_queue_depth);
1954 	dev->db_stride = 1 << NVME_CAP_STRIDE(dev->ctrl.cap);
1955 	dev->dbs = dev->bar + 4096;
1956 
1957 	/*
1958 	 * Temporary fix for the Apple controller found in the MacBook8,1 and
1959 	 * some MacBook7,1 to avoid controller resets and data loss.
1960 	 */
1961 	if (pdev->vendor == PCI_VENDOR_ID_APPLE && pdev->device == 0x2001) {
1962 		dev->q_depth = 2;
1963 		dev_warn(dev->ctrl.device, "detected Apple NVMe controller, "
1964 			"set queue depth=%u to work around controller resets\n",
1965 			dev->q_depth);
1966 	} else if (pdev->vendor == PCI_VENDOR_ID_SAMSUNG &&
1967 		   (pdev->device == 0xa821 || pdev->device == 0xa822) &&
1968 		   NVME_CAP_MQES(dev->ctrl.cap) == 0) {
1969 		dev->q_depth = 64;
1970 		dev_err(dev->ctrl.device, "detected PM1725 NVMe controller, "
1971                         "set queue depth=%u\n", dev->q_depth);
1972 	}
1973 
1974 	/*
1975 	 * CMBs can currently only exist on >=1.2 PCIe devices. We only
1976 	 * populate sysfs if a CMB is implemented. Since nvme_dev_attrs_group
1977 	 * has no name we can pass NULL as final argument to
1978 	 * sysfs_add_file_to_group.
1979 	 */
1980 
1981 	if (readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 2, 0)) {
1982 		dev->cmb = nvme_map_cmb(dev);
1983 		if (dev->cmb) {
1984 			if (sysfs_add_file_to_group(&dev->ctrl.device->kobj,
1985 						    &dev_attr_cmb.attr, NULL))
1986 				dev_warn(dev->ctrl.device,
1987 					 "failed to add sysfs attribute for CMB\n");
1988 		}
1989 	}
1990 
1991 	pci_enable_pcie_error_reporting(pdev);
1992 	pci_save_state(pdev);
1993 	return 0;
1994 
1995  disable:
1996 	pci_disable_device(pdev);
1997 	return result;
1998 }
1999 
2000 static void nvme_dev_unmap(struct nvme_dev *dev)
2001 {
2002 	if (dev->bar)
2003 		iounmap(dev->bar);
2004 	pci_release_mem_regions(to_pci_dev(dev->dev));
2005 }
2006 
2007 static void nvme_pci_disable(struct nvme_dev *dev)
2008 {
2009 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2010 
2011 	nvme_release_cmb(dev);
2012 	pci_free_irq_vectors(pdev);
2013 
2014 	if (pci_is_enabled(pdev)) {
2015 		pci_disable_pcie_error_reporting(pdev);
2016 		pci_disable_device(pdev);
2017 	}
2018 }
2019 
2020 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
2021 {
2022 	int i, queues;
2023 	bool dead = true;
2024 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2025 
2026 	mutex_lock(&dev->shutdown_lock);
2027 	if (pci_is_enabled(pdev)) {
2028 		u32 csts = readl(dev->bar + NVME_REG_CSTS);
2029 
2030 		if (dev->ctrl.state == NVME_CTRL_LIVE ||
2031 		    dev->ctrl.state == NVME_CTRL_RESETTING)
2032 			nvme_start_freeze(&dev->ctrl);
2033 		dead = !!((csts & NVME_CSTS_CFS) || !(csts & NVME_CSTS_RDY) ||
2034 			pdev->error_state  != pci_channel_io_normal);
2035 	}
2036 
2037 	/*
2038 	 * Give the controller a chance to complete all entered requests if
2039 	 * doing a safe shutdown.
2040 	 */
2041 	if (!dead) {
2042 		if (shutdown)
2043 			nvme_wait_freeze_timeout(&dev->ctrl, NVME_IO_TIMEOUT);
2044 
2045 		/*
2046 		 * If the controller is still alive tell it to stop using the
2047 		 * host memory buffer.  In theory the shutdown / reset should
2048 		 * make sure that it doesn't access the host memoery anymore,
2049 		 * but I'd rather be safe than sorry..
2050 		 */
2051 		if (dev->host_mem_descs)
2052 			nvme_set_host_mem(dev, 0);
2053 
2054 	}
2055 	nvme_stop_queues(&dev->ctrl);
2056 
2057 	queues = dev->online_queues - 1;
2058 	for (i = dev->ctrl.queue_count - 1; i > 0; i--)
2059 		nvme_suspend_queue(dev->queues[i]);
2060 
2061 	if (dead) {
2062 		/* A device might become IO incapable very soon during
2063 		 * probe, before the admin queue is configured. Thus,
2064 		 * queue_count can be 0 here.
2065 		 */
2066 		if (dev->ctrl.queue_count)
2067 			nvme_suspend_queue(dev->queues[0]);
2068 	} else {
2069 		nvme_disable_io_queues(dev, queues);
2070 		nvme_disable_admin_queue(dev, shutdown);
2071 	}
2072 	nvme_pci_disable(dev);
2073 
2074 	blk_mq_tagset_busy_iter(&dev->tagset, nvme_cancel_request, &dev->ctrl);
2075 	blk_mq_tagset_busy_iter(&dev->admin_tagset, nvme_cancel_request, &dev->ctrl);
2076 
2077 	/*
2078 	 * The driver will not be starting up queues again if shutting down so
2079 	 * must flush all entered requests to their failed completion to avoid
2080 	 * deadlocking blk-mq hot-cpu notifier.
2081 	 */
2082 	if (shutdown)
2083 		nvme_start_queues(&dev->ctrl);
2084 	mutex_unlock(&dev->shutdown_lock);
2085 }
2086 
2087 static int nvme_setup_prp_pools(struct nvme_dev *dev)
2088 {
2089 	dev->prp_page_pool = dma_pool_create("prp list page", dev->dev,
2090 						PAGE_SIZE, PAGE_SIZE, 0);
2091 	if (!dev->prp_page_pool)
2092 		return -ENOMEM;
2093 
2094 	/* Optimisation for I/Os between 4k and 128k */
2095 	dev->prp_small_pool = dma_pool_create("prp list 256", dev->dev,
2096 						256, 256, 0);
2097 	if (!dev->prp_small_pool) {
2098 		dma_pool_destroy(dev->prp_page_pool);
2099 		return -ENOMEM;
2100 	}
2101 	return 0;
2102 }
2103 
2104 static void nvme_release_prp_pools(struct nvme_dev *dev)
2105 {
2106 	dma_pool_destroy(dev->prp_page_pool);
2107 	dma_pool_destroy(dev->prp_small_pool);
2108 }
2109 
2110 static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
2111 {
2112 	struct nvme_dev *dev = to_nvme_dev(ctrl);
2113 
2114 	nvme_dbbuf_dma_free(dev);
2115 	put_device(dev->dev);
2116 	if (dev->tagset.tags)
2117 		blk_mq_free_tag_set(&dev->tagset);
2118 	if (dev->ctrl.admin_q)
2119 		blk_put_queue(dev->ctrl.admin_q);
2120 	kfree(dev->queues);
2121 	free_opal_dev(dev->ctrl.opal_dev);
2122 	kfree(dev);
2123 }
2124 
2125 static void nvme_remove_dead_ctrl(struct nvme_dev *dev, int status)
2126 {
2127 	dev_warn(dev->ctrl.device, "Removing after probe failure status: %d\n", status);
2128 
2129 	kref_get(&dev->ctrl.kref);
2130 	nvme_dev_disable(dev, false);
2131 	if (!schedule_work(&dev->remove_work))
2132 		nvme_put_ctrl(&dev->ctrl);
2133 }
2134 
2135 static void nvme_reset_work(struct work_struct *work)
2136 {
2137 	struct nvme_dev *dev =
2138 		container_of(work, struct nvme_dev, ctrl.reset_work);
2139 	bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL);
2140 	int result = -ENODEV;
2141 
2142 	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING))
2143 		goto out;
2144 
2145 	/*
2146 	 * If we're called to reset a live controller first shut it down before
2147 	 * moving on.
2148 	 */
2149 	if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
2150 		nvme_dev_disable(dev, false);
2151 
2152 	result = nvme_pci_enable(dev);
2153 	if (result)
2154 		goto out;
2155 
2156 	result = nvme_pci_configure_admin_queue(dev);
2157 	if (result)
2158 		goto out;
2159 
2160 	result = nvme_alloc_admin_tags(dev);
2161 	if (result)
2162 		goto out;
2163 
2164 	result = nvme_init_identify(&dev->ctrl);
2165 	if (result)
2166 		goto out;
2167 
2168 	if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
2169 		if (!dev->ctrl.opal_dev)
2170 			dev->ctrl.opal_dev =
2171 				init_opal_dev(&dev->ctrl, &nvme_sec_submit);
2172 		else if (was_suspend)
2173 			opal_unlock_from_suspend(dev->ctrl.opal_dev);
2174 	} else {
2175 		free_opal_dev(dev->ctrl.opal_dev);
2176 		dev->ctrl.opal_dev = NULL;
2177 	}
2178 
2179 	if (dev->ctrl.oacs & NVME_CTRL_OACS_DBBUF_SUPP) {
2180 		result = nvme_dbbuf_dma_alloc(dev);
2181 		if (result)
2182 			dev_warn(dev->dev,
2183 				 "unable to allocate dma for dbbuf\n");
2184 	}
2185 
2186 	if (dev->ctrl.hmpre) {
2187 		result = nvme_setup_host_mem(dev);
2188 		if (result < 0)
2189 			goto out;
2190 	}
2191 
2192 	result = nvme_setup_io_queues(dev);
2193 	if (result)
2194 		goto out;
2195 
2196 	/*
2197 	 * Keep the controller around but remove all namespaces if we don't have
2198 	 * any working I/O queue.
2199 	 */
2200 	if (dev->online_queues < 2) {
2201 		dev_warn(dev->ctrl.device, "IO queues not created\n");
2202 		nvme_kill_queues(&dev->ctrl);
2203 		nvme_remove_namespaces(&dev->ctrl);
2204 	} else {
2205 		nvme_start_queues(&dev->ctrl);
2206 		nvme_wait_freeze(&dev->ctrl);
2207 		nvme_dev_add(dev);
2208 		nvme_unfreeze(&dev->ctrl);
2209 	}
2210 
2211 	if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_LIVE)) {
2212 		dev_warn(dev->ctrl.device, "failed to mark controller live\n");
2213 		goto out;
2214 	}
2215 
2216 	nvme_start_ctrl(&dev->ctrl);
2217 	return;
2218 
2219  out:
2220 	nvme_remove_dead_ctrl(dev, result);
2221 }
2222 
2223 static void nvme_remove_dead_ctrl_work(struct work_struct *work)
2224 {
2225 	struct nvme_dev *dev = container_of(work, struct nvme_dev, remove_work);
2226 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2227 
2228 	nvme_kill_queues(&dev->ctrl);
2229 	if (pci_get_drvdata(pdev))
2230 		device_release_driver(&pdev->dev);
2231 	nvme_put_ctrl(&dev->ctrl);
2232 }
2233 
2234 static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
2235 {
2236 	*val = readl(to_nvme_dev(ctrl)->bar + off);
2237 	return 0;
2238 }
2239 
2240 static int nvme_pci_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
2241 {
2242 	writel(val, to_nvme_dev(ctrl)->bar + off);
2243 	return 0;
2244 }
2245 
2246 static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
2247 {
2248 	*val = readq(to_nvme_dev(ctrl)->bar + off);
2249 	return 0;
2250 }
2251 
2252 static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
2253 	.name			= "pcie",
2254 	.module			= THIS_MODULE,
2255 	.flags			= NVME_F_METADATA_SUPPORTED,
2256 	.reg_read32		= nvme_pci_reg_read32,
2257 	.reg_write32		= nvme_pci_reg_write32,
2258 	.reg_read64		= nvme_pci_reg_read64,
2259 	.free_ctrl		= nvme_pci_free_ctrl,
2260 	.submit_async_event	= nvme_pci_submit_async_event,
2261 };
2262 
2263 static int nvme_dev_map(struct nvme_dev *dev)
2264 {
2265 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2266 
2267 	if (pci_request_mem_regions(pdev, "nvme"))
2268 		return -ENODEV;
2269 
2270 	if (nvme_remap_bar(dev, NVME_REG_DBS + 4096))
2271 		goto release;
2272 
2273 	return 0;
2274   release:
2275 	pci_release_mem_regions(pdev);
2276 	return -ENODEV;
2277 }
2278 
2279 static unsigned long check_dell_samsung_bug(struct pci_dev *pdev)
2280 {
2281 	if (pdev->vendor == 0x144d && pdev->device == 0xa802) {
2282 		/*
2283 		 * Several Samsung devices seem to drop off the PCIe bus
2284 		 * randomly when APST is on and uses the deepest sleep state.
2285 		 * This has been observed on a Samsung "SM951 NVMe SAMSUNG
2286 		 * 256GB", a "PM951 NVMe SAMSUNG 512GB", and a "Samsung SSD
2287 		 * 950 PRO 256GB", but it seems to be restricted to two Dell
2288 		 * laptops.
2289 		 */
2290 		if (dmi_match(DMI_SYS_VENDOR, "Dell Inc.") &&
2291 		    (dmi_match(DMI_PRODUCT_NAME, "XPS 15 9550") ||
2292 		     dmi_match(DMI_PRODUCT_NAME, "Precision 5510")))
2293 			return NVME_QUIRK_NO_DEEPEST_PS;
2294 	}
2295 
2296 	return 0;
2297 }
2298 
2299 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
2300 {
2301 	int node, result = -ENOMEM;
2302 	struct nvme_dev *dev;
2303 	unsigned long quirks = id->driver_data;
2304 
2305 	node = dev_to_node(&pdev->dev);
2306 	if (node == NUMA_NO_NODE)
2307 		set_dev_node(&pdev->dev, first_memory_node);
2308 
2309 	dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
2310 	if (!dev)
2311 		return -ENOMEM;
2312 	dev->queues = kzalloc_node((num_possible_cpus() + 1) * sizeof(void *),
2313 							GFP_KERNEL, node);
2314 	if (!dev->queues)
2315 		goto free;
2316 
2317 	dev->dev = get_device(&pdev->dev);
2318 	pci_set_drvdata(pdev, dev);
2319 
2320 	result = nvme_dev_map(dev);
2321 	if (result)
2322 		goto put_pci;
2323 
2324 	INIT_WORK(&dev->ctrl.reset_work, nvme_reset_work);
2325 	INIT_WORK(&dev->remove_work, nvme_remove_dead_ctrl_work);
2326 	mutex_init(&dev->shutdown_lock);
2327 	init_completion(&dev->ioq_wait);
2328 
2329 	result = nvme_setup_prp_pools(dev);
2330 	if (result)
2331 		goto unmap;
2332 
2333 	quirks |= check_dell_samsung_bug(pdev);
2334 
2335 	result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
2336 			quirks);
2337 	if (result)
2338 		goto release_pools;
2339 
2340 	nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_RESETTING);
2341 	dev_info(dev->ctrl.device, "pci function %s\n", dev_name(&pdev->dev));
2342 
2343 	queue_work(nvme_wq, &dev->ctrl.reset_work);
2344 	return 0;
2345 
2346  release_pools:
2347 	nvme_release_prp_pools(dev);
2348  unmap:
2349 	nvme_dev_unmap(dev);
2350  put_pci:
2351 	put_device(dev->dev);
2352  free:
2353 	kfree(dev->queues);
2354 	kfree(dev);
2355 	return result;
2356 }
2357 
2358 static void nvme_reset_prepare(struct pci_dev *pdev)
2359 {
2360 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2361 	nvme_dev_disable(dev, false);
2362 }
2363 
2364 static void nvme_reset_done(struct pci_dev *pdev)
2365 {
2366 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2367 	nvme_reset_ctrl(&dev->ctrl);
2368 }
2369 
2370 static void nvme_shutdown(struct pci_dev *pdev)
2371 {
2372 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2373 	nvme_dev_disable(dev, true);
2374 }
2375 
2376 /*
2377  * The driver's remove may be called on a device in a partially initialized
2378  * state. This function must not have any dependencies on the device state in
2379  * order to proceed.
2380  */
2381 static void nvme_remove(struct pci_dev *pdev)
2382 {
2383 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2384 
2385 	nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING);
2386 
2387 	cancel_work_sync(&dev->ctrl.reset_work);
2388 	pci_set_drvdata(pdev, NULL);
2389 
2390 	if (!pci_device_is_present(pdev)) {
2391 		nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DEAD);
2392 		nvme_dev_disable(dev, false);
2393 	}
2394 
2395 	flush_work(&dev->ctrl.reset_work);
2396 	nvme_stop_ctrl(&dev->ctrl);
2397 	nvme_remove_namespaces(&dev->ctrl);
2398 	nvme_dev_disable(dev, true);
2399 	nvme_free_host_mem(dev);
2400 	nvme_dev_remove_admin(dev);
2401 	nvme_free_queues(dev, 0);
2402 	nvme_uninit_ctrl(&dev->ctrl);
2403 	nvme_release_prp_pools(dev);
2404 	nvme_dev_unmap(dev);
2405 	nvme_put_ctrl(&dev->ctrl);
2406 }
2407 
2408 static int nvme_pci_sriov_configure(struct pci_dev *pdev, int numvfs)
2409 {
2410 	int ret = 0;
2411 
2412 	if (numvfs == 0) {
2413 		if (pci_vfs_assigned(pdev)) {
2414 			dev_warn(&pdev->dev,
2415 				"Cannot disable SR-IOV VFs while assigned\n");
2416 			return -EPERM;
2417 		}
2418 		pci_disable_sriov(pdev);
2419 		return 0;
2420 	}
2421 
2422 	ret = pci_enable_sriov(pdev, numvfs);
2423 	return ret ? ret : numvfs;
2424 }
2425 
2426 #ifdef CONFIG_PM_SLEEP
2427 static int nvme_suspend(struct device *dev)
2428 {
2429 	struct pci_dev *pdev = to_pci_dev(dev);
2430 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2431 
2432 	nvme_dev_disable(ndev, true);
2433 	return 0;
2434 }
2435 
2436 static int nvme_resume(struct device *dev)
2437 {
2438 	struct pci_dev *pdev = to_pci_dev(dev);
2439 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2440 
2441 	nvme_reset_ctrl(&ndev->ctrl);
2442 	return 0;
2443 }
2444 #endif
2445 
2446 static SIMPLE_DEV_PM_OPS(nvme_dev_pm_ops, nvme_suspend, nvme_resume);
2447 
2448 static pci_ers_result_t nvme_error_detected(struct pci_dev *pdev,
2449 						pci_channel_state_t state)
2450 {
2451 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2452 
2453 	/*
2454 	 * A frozen channel requires a reset. When detected, this method will
2455 	 * shutdown the controller to quiesce. The controller will be restarted
2456 	 * after the slot reset through driver's slot_reset callback.
2457 	 */
2458 	switch (state) {
2459 	case pci_channel_io_normal:
2460 		return PCI_ERS_RESULT_CAN_RECOVER;
2461 	case pci_channel_io_frozen:
2462 		dev_warn(dev->ctrl.device,
2463 			"frozen state error detected, reset controller\n");
2464 		nvme_dev_disable(dev, false);
2465 		return PCI_ERS_RESULT_NEED_RESET;
2466 	case pci_channel_io_perm_failure:
2467 		dev_warn(dev->ctrl.device,
2468 			"failure state error detected, request disconnect\n");
2469 		return PCI_ERS_RESULT_DISCONNECT;
2470 	}
2471 	return PCI_ERS_RESULT_NEED_RESET;
2472 }
2473 
2474 static pci_ers_result_t nvme_slot_reset(struct pci_dev *pdev)
2475 {
2476 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2477 
2478 	dev_info(dev->ctrl.device, "restart after slot reset\n");
2479 	pci_restore_state(pdev);
2480 	nvme_reset_ctrl(&dev->ctrl);
2481 	return PCI_ERS_RESULT_RECOVERED;
2482 }
2483 
2484 static void nvme_error_resume(struct pci_dev *pdev)
2485 {
2486 	pci_cleanup_aer_uncorrect_error_status(pdev);
2487 }
2488 
2489 static const struct pci_error_handlers nvme_err_handler = {
2490 	.error_detected	= nvme_error_detected,
2491 	.slot_reset	= nvme_slot_reset,
2492 	.resume		= nvme_error_resume,
2493 	.reset_prepare	= nvme_reset_prepare,
2494 	.reset_done	= nvme_reset_done,
2495 };
2496 
2497 static const struct pci_device_id nvme_id_table[] = {
2498 	{ PCI_VDEVICE(INTEL, 0x0953),
2499 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2500 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2501 	{ PCI_VDEVICE(INTEL, 0x0a53),
2502 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2503 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2504 	{ PCI_VDEVICE(INTEL, 0x0a54),
2505 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2506 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2507 	{ PCI_VDEVICE(INTEL, 0x0a55),
2508 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2509 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2510 	{ PCI_VDEVICE(INTEL, 0xf1a5),	/* Intel 600P/P3100 */
2511 		.driver_data = NVME_QUIRK_NO_DEEPEST_PS },
2512 	{ PCI_VDEVICE(INTEL, 0x5845),	/* Qemu emulated controller */
2513 		.driver_data = NVME_QUIRK_IDENTIFY_CNS, },
2514 	{ PCI_DEVICE(0x1c58, 0x0003),	/* HGST adapter */
2515 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2516 	{ PCI_DEVICE(0x1c5f, 0x0540),	/* Memblaze Pblaze4 adapter */
2517 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2518 	{ PCI_DEVICE(0x144d, 0xa821),   /* Samsung PM1725 */
2519 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2520 	{ PCI_DEVICE(0x144d, 0xa822),   /* Samsung PM1725a */
2521 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2522 	{ PCI_DEVICE(0x1d1d, 0x1f1f),	/* LighNVM qemu device */
2523 		.driver_data = NVME_QUIRK_LIGHTNVM, },
2524 	{ PCI_DEVICE(0x1d1d, 0x2807),	/* CNEX WL */
2525 		.driver_data = NVME_QUIRK_LIGHTNVM, },
2526 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
2527 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
2528 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2003) },
2529 	{ 0, }
2530 };
2531 MODULE_DEVICE_TABLE(pci, nvme_id_table);
2532 
2533 static struct pci_driver nvme_driver = {
2534 	.name		= "nvme",
2535 	.id_table	= nvme_id_table,
2536 	.probe		= nvme_probe,
2537 	.remove		= nvme_remove,
2538 	.shutdown	= nvme_shutdown,
2539 	.driver		= {
2540 		.pm	= &nvme_dev_pm_ops,
2541 	},
2542 	.sriov_configure = nvme_pci_sriov_configure,
2543 	.err_handler	= &nvme_err_handler,
2544 };
2545 
2546 static int __init nvme_init(void)
2547 {
2548 	return pci_register_driver(&nvme_driver);
2549 }
2550 
2551 static void __exit nvme_exit(void)
2552 {
2553 	pci_unregister_driver(&nvme_driver);
2554 	_nvme_check_size();
2555 }
2556 
2557 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
2558 MODULE_LICENSE("GPL");
2559 MODULE_VERSION("1.0");
2560 module_init(nvme_init);
2561 module_exit(nvme_exit);
2562