xref: /openbmc/linux/drivers/nvme/host/pci.c (revision 6d99a79c)
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/async.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/once.h>
28 #include <linux/pci.h>
29 #include <linux/t10-pi.h>
30 #include <linux/types.h>
31 #include <linux/io-64-nonatomic-lo-hi.h>
32 #include <linux/sed-opal.h>
33 #include <linux/pci-p2pdma.h>
34 
35 #include "nvme.h"
36 
37 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
38 #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
39 
40 #define SGES_PER_PAGE	(PAGE_SIZE / sizeof(struct nvme_sgl_desc))
41 
42 /*
43  * These can be higher, but we need to ensure that any command doesn't
44  * require an sg allocation that needs more than a page of data.
45  */
46 #define NVME_MAX_KB_SZ	4096
47 #define NVME_MAX_SEGS	127
48 
49 static int use_threaded_interrupts;
50 module_param(use_threaded_interrupts, int, 0);
51 
52 static bool use_cmb_sqes = true;
53 module_param(use_cmb_sqes, bool, 0444);
54 MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes");
55 
56 static unsigned int max_host_mem_size_mb = 128;
57 module_param(max_host_mem_size_mb, uint, 0444);
58 MODULE_PARM_DESC(max_host_mem_size_mb,
59 	"Maximum Host Memory Buffer (HMB) size per controller (in MiB)");
60 
61 static unsigned int sgl_threshold = SZ_32K;
62 module_param(sgl_threshold, uint, 0644);
63 MODULE_PARM_DESC(sgl_threshold,
64 		"Use SGLs when average request segment size is larger or equal to "
65 		"this size. Use 0 to disable SGLs.");
66 
67 static int io_queue_depth_set(const char *val, const struct kernel_param *kp);
68 static const struct kernel_param_ops io_queue_depth_ops = {
69 	.set = io_queue_depth_set,
70 	.get = param_get_int,
71 };
72 
73 static int io_queue_depth = 1024;
74 module_param_cb(io_queue_depth, &io_queue_depth_ops, &io_queue_depth, 0644);
75 MODULE_PARM_DESC(io_queue_depth, "set io queue depth, should >= 2");
76 
77 struct nvme_dev;
78 struct nvme_queue;
79 
80 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
81 
82 /*
83  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
84  */
85 struct nvme_dev {
86 	struct nvme_queue *queues;
87 	struct blk_mq_tag_set tagset;
88 	struct blk_mq_tag_set admin_tagset;
89 	u32 __iomem *dbs;
90 	struct device *dev;
91 	struct dma_pool *prp_page_pool;
92 	struct dma_pool *prp_small_pool;
93 	unsigned online_queues;
94 	unsigned max_qid;
95 	unsigned int num_vecs;
96 	int q_depth;
97 	u32 db_stride;
98 	void __iomem *bar;
99 	unsigned long bar_mapped_size;
100 	struct work_struct remove_work;
101 	struct mutex shutdown_lock;
102 	bool subsystem;
103 	u64 cmb_size;
104 	bool cmb_use_sqes;
105 	u32 cmbsz;
106 	u32 cmbloc;
107 	struct nvme_ctrl ctrl;
108 	struct completion ioq_wait;
109 
110 	mempool_t *iod_mempool;
111 
112 	/* shadow doorbell buffer support: */
113 	u32 *dbbuf_dbs;
114 	dma_addr_t dbbuf_dbs_dma_addr;
115 	u32 *dbbuf_eis;
116 	dma_addr_t dbbuf_eis_dma_addr;
117 
118 	/* host memory buffer support: */
119 	u64 host_mem_size;
120 	u32 nr_host_mem_descs;
121 	dma_addr_t host_mem_descs_dma;
122 	struct nvme_host_mem_buf_desc *host_mem_descs;
123 	void **host_mem_desc_bufs;
124 };
125 
126 static int io_queue_depth_set(const char *val, const struct kernel_param *kp)
127 {
128 	int n = 0, ret;
129 
130 	ret = kstrtoint(val, 10, &n);
131 	if (ret != 0 || n < 2)
132 		return -EINVAL;
133 
134 	return param_set_int(val, kp);
135 }
136 
137 static inline unsigned int sq_idx(unsigned int qid, u32 stride)
138 {
139 	return qid * 2 * stride;
140 }
141 
142 static inline unsigned int cq_idx(unsigned int qid, u32 stride)
143 {
144 	return (qid * 2 + 1) * stride;
145 }
146 
147 static inline struct nvme_dev *to_nvme_dev(struct nvme_ctrl *ctrl)
148 {
149 	return container_of(ctrl, struct nvme_dev, ctrl);
150 }
151 
152 /*
153  * An NVM Express queue.  Each device has at least two (one for admin
154  * commands and one for I/O commands).
155  */
156 struct nvme_queue {
157 	struct device *q_dmadev;
158 	struct nvme_dev *dev;
159 	spinlock_t sq_lock;
160 	struct nvme_command *sq_cmds;
161 	bool sq_cmds_is_io;
162 	spinlock_t cq_lock ____cacheline_aligned_in_smp;
163 	volatile struct nvme_completion *cqes;
164 	struct blk_mq_tags **tags;
165 	dma_addr_t sq_dma_addr;
166 	dma_addr_t cq_dma_addr;
167 	u32 __iomem *q_db;
168 	u16 q_depth;
169 	s16 cq_vector;
170 	u16 sq_tail;
171 	u16 cq_head;
172 	u16 last_cq_head;
173 	u16 qid;
174 	u8 cq_phase;
175 	u32 *dbbuf_sq_db;
176 	u32 *dbbuf_cq_db;
177 	u32 *dbbuf_sq_ei;
178 	u32 *dbbuf_cq_ei;
179 };
180 
181 /*
182  * The nvme_iod describes the data in an I/O, including the list of PRP
183  * entries.  You can't see it in this data structure because C doesn't let
184  * me express that.  Use nvme_init_iod to ensure there's enough space
185  * allocated to store the PRP list.
186  */
187 struct nvme_iod {
188 	struct nvme_request req;
189 	struct nvme_queue *nvmeq;
190 	bool use_sgl;
191 	int aborted;
192 	int npages;		/* In the PRP list. 0 means small pool in use */
193 	int nents;		/* Used in scatterlist */
194 	int length;		/* Of data, in bytes */
195 	dma_addr_t first_dma;
196 	struct scatterlist meta_sg; /* metadata requires single contiguous buffer */
197 	struct scatterlist *sg;
198 	struct scatterlist inline_sg[0];
199 };
200 
201 /*
202  * Check we didin't inadvertently grow the command struct
203  */
204 static inline void _nvme_check_size(void)
205 {
206 	BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
207 	BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
208 	BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
209 	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
210 	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
211 	BUILD_BUG_ON(sizeof(struct nvme_format_cmd) != 64);
212 	BUILD_BUG_ON(sizeof(struct nvme_abort_cmd) != 64);
213 	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
214 	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != NVME_IDENTIFY_DATA_SIZE);
215 	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != NVME_IDENTIFY_DATA_SIZE);
216 	BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
217 	BUILD_BUG_ON(sizeof(struct nvme_smart_log) != 512);
218 	BUILD_BUG_ON(sizeof(struct nvme_dbbuf) != 64);
219 }
220 
221 static inline unsigned int nvme_dbbuf_size(u32 stride)
222 {
223 	return ((num_possible_cpus() + 1) * 8 * stride);
224 }
225 
226 static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
227 {
228 	unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
229 
230 	if (dev->dbbuf_dbs)
231 		return 0;
232 
233 	dev->dbbuf_dbs = dma_alloc_coherent(dev->dev, mem_size,
234 					    &dev->dbbuf_dbs_dma_addr,
235 					    GFP_KERNEL);
236 	if (!dev->dbbuf_dbs)
237 		return -ENOMEM;
238 	dev->dbbuf_eis = dma_alloc_coherent(dev->dev, mem_size,
239 					    &dev->dbbuf_eis_dma_addr,
240 					    GFP_KERNEL);
241 	if (!dev->dbbuf_eis) {
242 		dma_free_coherent(dev->dev, mem_size,
243 				  dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
244 		dev->dbbuf_dbs = NULL;
245 		return -ENOMEM;
246 	}
247 
248 	return 0;
249 }
250 
251 static void nvme_dbbuf_dma_free(struct nvme_dev *dev)
252 {
253 	unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
254 
255 	if (dev->dbbuf_dbs) {
256 		dma_free_coherent(dev->dev, mem_size,
257 				  dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
258 		dev->dbbuf_dbs = NULL;
259 	}
260 	if (dev->dbbuf_eis) {
261 		dma_free_coherent(dev->dev, mem_size,
262 				  dev->dbbuf_eis, dev->dbbuf_eis_dma_addr);
263 		dev->dbbuf_eis = NULL;
264 	}
265 }
266 
267 static void nvme_dbbuf_init(struct nvme_dev *dev,
268 			    struct nvme_queue *nvmeq, int qid)
269 {
270 	if (!dev->dbbuf_dbs || !qid)
271 		return;
272 
273 	nvmeq->dbbuf_sq_db = &dev->dbbuf_dbs[sq_idx(qid, dev->db_stride)];
274 	nvmeq->dbbuf_cq_db = &dev->dbbuf_dbs[cq_idx(qid, dev->db_stride)];
275 	nvmeq->dbbuf_sq_ei = &dev->dbbuf_eis[sq_idx(qid, dev->db_stride)];
276 	nvmeq->dbbuf_cq_ei = &dev->dbbuf_eis[cq_idx(qid, dev->db_stride)];
277 }
278 
279 static void nvme_dbbuf_set(struct nvme_dev *dev)
280 {
281 	struct nvme_command c;
282 
283 	if (!dev->dbbuf_dbs)
284 		return;
285 
286 	memset(&c, 0, sizeof(c));
287 	c.dbbuf.opcode = nvme_admin_dbbuf;
288 	c.dbbuf.prp1 = cpu_to_le64(dev->dbbuf_dbs_dma_addr);
289 	c.dbbuf.prp2 = cpu_to_le64(dev->dbbuf_eis_dma_addr);
290 
291 	if (nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0)) {
292 		dev_warn(dev->ctrl.device, "unable to set dbbuf\n");
293 		/* Free memory and continue on */
294 		nvme_dbbuf_dma_free(dev);
295 	}
296 }
297 
298 static inline int nvme_dbbuf_need_event(u16 event_idx, u16 new_idx, u16 old)
299 {
300 	return (u16)(new_idx - event_idx - 1) < (u16)(new_idx - old);
301 }
302 
303 /* Update dbbuf and return true if an MMIO is required */
304 static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db,
305 					      volatile u32 *dbbuf_ei)
306 {
307 	if (dbbuf_db) {
308 		u16 old_value;
309 
310 		/*
311 		 * Ensure that the queue is written before updating
312 		 * the doorbell in memory
313 		 */
314 		wmb();
315 
316 		old_value = *dbbuf_db;
317 		*dbbuf_db = value;
318 
319 		/*
320 		 * Ensure that the doorbell is updated before reading the event
321 		 * index from memory.  The controller needs to provide similar
322 		 * ordering to ensure the envent index is updated before reading
323 		 * the doorbell.
324 		 */
325 		mb();
326 
327 		if (!nvme_dbbuf_need_event(*dbbuf_ei, value, old_value))
328 			return false;
329 	}
330 
331 	return true;
332 }
333 
334 /*
335  * Max size of iod being embedded in the request payload
336  */
337 #define NVME_INT_PAGES		2
338 #define NVME_INT_BYTES(dev)	(NVME_INT_PAGES * (dev)->ctrl.page_size)
339 
340 /*
341  * Will slightly overestimate the number of pages needed.  This is OK
342  * as it only leads to a small amount of wasted memory for the lifetime of
343  * the I/O.
344  */
345 static int nvme_npages(unsigned size, struct nvme_dev *dev)
346 {
347 	unsigned nprps = DIV_ROUND_UP(size + dev->ctrl.page_size,
348 				      dev->ctrl.page_size);
349 	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
350 }
351 
352 /*
353  * Calculates the number of pages needed for the SGL segments. For example a 4k
354  * page can accommodate 256 SGL descriptors.
355  */
356 static int nvme_pci_npages_sgl(unsigned int num_seg)
357 {
358 	return DIV_ROUND_UP(num_seg * sizeof(struct nvme_sgl_desc), PAGE_SIZE);
359 }
360 
361 static unsigned int nvme_pci_iod_alloc_size(struct nvme_dev *dev,
362 		unsigned int size, unsigned int nseg, bool use_sgl)
363 {
364 	size_t alloc_size;
365 
366 	if (use_sgl)
367 		alloc_size = sizeof(__le64 *) * nvme_pci_npages_sgl(nseg);
368 	else
369 		alloc_size = sizeof(__le64 *) * nvme_npages(size, dev);
370 
371 	return alloc_size + sizeof(struct scatterlist) * nseg;
372 }
373 
374 static unsigned int nvme_pci_cmd_size(struct nvme_dev *dev, bool use_sgl)
375 {
376 	unsigned int alloc_size = nvme_pci_iod_alloc_size(dev,
377 				    NVME_INT_BYTES(dev), NVME_INT_PAGES,
378 				    use_sgl);
379 
380 	return sizeof(struct nvme_iod) + alloc_size;
381 }
382 
383 static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
384 				unsigned int hctx_idx)
385 {
386 	struct nvme_dev *dev = data;
387 	struct nvme_queue *nvmeq = &dev->queues[0];
388 
389 	WARN_ON(hctx_idx != 0);
390 	WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);
391 	WARN_ON(nvmeq->tags);
392 
393 	hctx->driver_data = nvmeq;
394 	nvmeq->tags = &dev->admin_tagset.tags[0];
395 	return 0;
396 }
397 
398 static void nvme_admin_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
399 {
400 	struct nvme_queue *nvmeq = hctx->driver_data;
401 
402 	nvmeq->tags = NULL;
403 }
404 
405 static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
406 			  unsigned int hctx_idx)
407 {
408 	struct nvme_dev *dev = data;
409 	struct nvme_queue *nvmeq = &dev->queues[hctx_idx + 1];
410 
411 	if (!nvmeq->tags)
412 		nvmeq->tags = &dev->tagset.tags[hctx_idx];
413 
414 	WARN_ON(dev->tagset.tags[hctx_idx] != hctx->tags);
415 	hctx->driver_data = nvmeq;
416 	return 0;
417 }
418 
419 static int nvme_init_request(struct blk_mq_tag_set *set, struct request *req,
420 		unsigned int hctx_idx, unsigned int numa_node)
421 {
422 	struct nvme_dev *dev = set->driver_data;
423 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
424 	int queue_idx = (set == &dev->tagset) ? hctx_idx + 1 : 0;
425 	struct nvme_queue *nvmeq = &dev->queues[queue_idx];
426 
427 	BUG_ON(!nvmeq);
428 	iod->nvmeq = nvmeq;
429 
430 	nvme_req(req)->ctrl = &dev->ctrl;
431 	return 0;
432 }
433 
434 static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
435 {
436 	struct nvme_dev *dev = set->driver_data;
437 
438 	return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev),
439 			dev->num_vecs > 1 ? 1 /* admin queue */ : 0);
440 }
441 
442 /**
443  * nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
444  * @nvmeq: The queue to use
445  * @cmd: The command to send
446  */
447 static void nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
448 {
449 	spin_lock(&nvmeq->sq_lock);
450 
451 	memcpy(&nvmeq->sq_cmds[nvmeq->sq_tail], cmd, sizeof(*cmd));
452 
453 	if (++nvmeq->sq_tail == nvmeq->q_depth)
454 		nvmeq->sq_tail = 0;
455 	if (nvme_dbbuf_update_and_check_event(nvmeq->sq_tail,
456 			nvmeq->dbbuf_sq_db, nvmeq->dbbuf_sq_ei))
457 		writel(nvmeq->sq_tail, nvmeq->q_db);
458 	spin_unlock(&nvmeq->sq_lock);
459 }
460 
461 static void **nvme_pci_iod_list(struct request *req)
462 {
463 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
464 	return (void **)(iod->sg + blk_rq_nr_phys_segments(req));
465 }
466 
467 static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req)
468 {
469 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
470 	int nseg = blk_rq_nr_phys_segments(req);
471 	unsigned int avg_seg_size;
472 
473 	if (nseg == 0)
474 		return false;
475 
476 	avg_seg_size = DIV_ROUND_UP(blk_rq_payload_bytes(req), nseg);
477 
478 	if (!(dev->ctrl.sgls & ((1 << 0) | (1 << 1))))
479 		return false;
480 	if (!iod->nvmeq->qid)
481 		return false;
482 	if (!sgl_threshold || avg_seg_size < sgl_threshold)
483 		return false;
484 	return true;
485 }
486 
487 static blk_status_t nvme_init_iod(struct request *rq, struct nvme_dev *dev)
488 {
489 	struct nvme_iod *iod = blk_mq_rq_to_pdu(rq);
490 	int nseg = blk_rq_nr_phys_segments(rq);
491 	unsigned int size = blk_rq_payload_bytes(rq);
492 
493 	iod->use_sgl = nvme_pci_use_sgls(dev, rq);
494 
495 	if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
496 		iod->sg = mempool_alloc(dev->iod_mempool, GFP_ATOMIC);
497 		if (!iod->sg)
498 			return BLK_STS_RESOURCE;
499 	} else {
500 		iod->sg = iod->inline_sg;
501 	}
502 
503 	iod->aborted = 0;
504 	iod->npages = -1;
505 	iod->nents = 0;
506 	iod->length = size;
507 
508 	return BLK_STS_OK;
509 }
510 
511 static void nvme_free_iod(struct nvme_dev *dev, struct request *req)
512 {
513 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
514 	const int last_prp = dev->ctrl.page_size / sizeof(__le64) - 1;
515 	dma_addr_t dma_addr = iod->first_dma, next_dma_addr;
516 
517 	int i;
518 
519 	if (iod->npages == 0)
520 		dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0],
521 			dma_addr);
522 
523 	for (i = 0; i < iod->npages; i++) {
524 		void *addr = nvme_pci_iod_list(req)[i];
525 
526 		if (iod->use_sgl) {
527 			struct nvme_sgl_desc *sg_list = addr;
528 
529 			next_dma_addr =
530 			    le64_to_cpu((sg_list[SGES_PER_PAGE - 1]).addr);
531 		} else {
532 			__le64 *prp_list = addr;
533 
534 			next_dma_addr = le64_to_cpu(prp_list[last_prp]);
535 		}
536 
537 		dma_pool_free(dev->prp_page_pool, addr, dma_addr);
538 		dma_addr = next_dma_addr;
539 	}
540 
541 	if (iod->sg != iod->inline_sg)
542 		mempool_free(iod->sg, dev->iod_mempool);
543 }
544 
545 static void nvme_print_sgl(struct scatterlist *sgl, int nents)
546 {
547 	int i;
548 	struct scatterlist *sg;
549 
550 	for_each_sg(sgl, sg, nents, i) {
551 		dma_addr_t phys = sg_phys(sg);
552 		pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d "
553 			"dma_address:%pad dma_length:%d\n",
554 			i, &phys, sg->offset, sg->length, &sg_dma_address(sg),
555 			sg_dma_len(sg));
556 	}
557 }
558 
559 static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev,
560 		struct request *req, struct nvme_rw_command *cmnd)
561 {
562 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
563 	struct dma_pool *pool;
564 	int length = blk_rq_payload_bytes(req);
565 	struct scatterlist *sg = iod->sg;
566 	int dma_len = sg_dma_len(sg);
567 	u64 dma_addr = sg_dma_address(sg);
568 	u32 page_size = dev->ctrl.page_size;
569 	int offset = dma_addr & (page_size - 1);
570 	__le64 *prp_list;
571 	void **list = nvme_pci_iod_list(req);
572 	dma_addr_t prp_dma;
573 	int nprps, i;
574 
575 	length -= (page_size - offset);
576 	if (length <= 0) {
577 		iod->first_dma = 0;
578 		goto done;
579 	}
580 
581 	dma_len -= (page_size - offset);
582 	if (dma_len) {
583 		dma_addr += (page_size - offset);
584 	} else {
585 		sg = sg_next(sg);
586 		dma_addr = sg_dma_address(sg);
587 		dma_len = sg_dma_len(sg);
588 	}
589 
590 	if (length <= page_size) {
591 		iod->first_dma = dma_addr;
592 		goto done;
593 	}
594 
595 	nprps = DIV_ROUND_UP(length, page_size);
596 	if (nprps <= (256 / 8)) {
597 		pool = dev->prp_small_pool;
598 		iod->npages = 0;
599 	} else {
600 		pool = dev->prp_page_pool;
601 		iod->npages = 1;
602 	}
603 
604 	prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
605 	if (!prp_list) {
606 		iod->first_dma = dma_addr;
607 		iod->npages = -1;
608 		return BLK_STS_RESOURCE;
609 	}
610 	list[0] = prp_list;
611 	iod->first_dma = prp_dma;
612 	i = 0;
613 	for (;;) {
614 		if (i == page_size >> 3) {
615 			__le64 *old_prp_list = prp_list;
616 			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
617 			if (!prp_list)
618 				return BLK_STS_RESOURCE;
619 			list[iod->npages++] = prp_list;
620 			prp_list[0] = old_prp_list[i - 1];
621 			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
622 			i = 1;
623 		}
624 		prp_list[i++] = cpu_to_le64(dma_addr);
625 		dma_len -= page_size;
626 		dma_addr += page_size;
627 		length -= page_size;
628 		if (length <= 0)
629 			break;
630 		if (dma_len > 0)
631 			continue;
632 		if (unlikely(dma_len < 0))
633 			goto bad_sgl;
634 		sg = sg_next(sg);
635 		dma_addr = sg_dma_address(sg);
636 		dma_len = sg_dma_len(sg);
637 	}
638 
639 done:
640 	cmnd->dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
641 	cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma);
642 
643 	return BLK_STS_OK;
644 
645  bad_sgl:
646 	WARN(DO_ONCE(nvme_print_sgl, iod->sg, iod->nents),
647 			"Invalid SGL for payload:%d nents:%d\n",
648 			blk_rq_payload_bytes(req), iod->nents);
649 	return BLK_STS_IOERR;
650 }
651 
652 static void nvme_pci_sgl_set_data(struct nvme_sgl_desc *sge,
653 		struct scatterlist *sg)
654 {
655 	sge->addr = cpu_to_le64(sg_dma_address(sg));
656 	sge->length = cpu_to_le32(sg_dma_len(sg));
657 	sge->type = NVME_SGL_FMT_DATA_DESC << 4;
658 }
659 
660 static void nvme_pci_sgl_set_seg(struct nvme_sgl_desc *sge,
661 		dma_addr_t dma_addr, int entries)
662 {
663 	sge->addr = cpu_to_le64(dma_addr);
664 	if (entries < SGES_PER_PAGE) {
665 		sge->length = cpu_to_le32(entries * sizeof(*sge));
666 		sge->type = NVME_SGL_FMT_LAST_SEG_DESC << 4;
667 	} else {
668 		sge->length = cpu_to_le32(PAGE_SIZE);
669 		sge->type = NVME_SGL_FMT_SEG_DESC << 4;
670 	}
671 }
672 
673 static blk_status_t nvme_pci_setup_sgls(struct nvme_dev *dev,
674 		struct request *req, struct nvme_rw_command *cmd, int entries)
675 {
676 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
677 	struct dma_pool *pool;
678 	struct nvme_sgl_desc *sg_list;
679 	struct scatterlist *sg = iod->sg;
680 	dma_addr_t sgl_dma;
681 	int i = 0;
682 
683 	/* setting the transfer type as SGL */
684 	cmd->flags = NVME_CMD_SGL_METABUF;
685 
686 	if (entries == 1) {
687 		nvme_pci_sgl_set_data(&cmd->dptr.sgl, sg);
688 		return BLK_STS_OK;
689 	}
690 
691 	if (entries <= (256 / sizeof(struct nvme_sgl_desc))) {
692 		pool = dev->prp_small_pool;
693 		iod->npages = 0;
694 	} else {
695 		pool = dev->prp_page_pool;
696 		iod->npages = 1;
697 	}
698 
699 	sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
700 	if (!sg_list) {
701 		iod->npages = -1;
702 		return BLK_STS_RESOURCE;
703 	}
704 
705 	nvme_pci_iod_list(req)[0] = sg_list;
706 	iod->first_dma = sgl_dma;
707 
708 	nvme_pci_sgl_set_seg(&cmd->dptr.sgl, sgl_dma, entries);
709 
710 	do {
711 		if (i == SGES_PER_PAGE) {
712 			struct nvme_sgl_desc *old_sg_desc = sg_list;
713 			struct nvme_sgl_desc *link = &old_sg_desc[i - 1];
714 
715 			sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
716 			if (!sg_list)
717 				return BLK_STS_RESOURCE;
718 
719 			i = 0;
720 			nvme_pci_iod_list(req)[iod->npages++] = sg_list;
721 			sg_list[i++] = *link;
722 			nvme_pci_sgl_set_seg(link, sgl_dma, entries);
723 		}
724 
725 		nvme_pci_sgl_set_data(&sg_list[i++], sg);
726 		sg = sg_next(sg);
727 	} while (--entries > 0);
728 
729 	return BLK_STS_OK;
730 }
731 
732 static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
733 		struct nvme_command *cmnd)
734 {
735 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
736 	struct request_queue *q = req->q;
737 	enum dma_data_direction dma_dir = rq_data_dir(req) ?
738 			DMA_TO_DEVICE : DMA_FROM_DEVICE;
739 	blk_status_t ret = BLK_STS_IOERR;
740 	int nr_mapped;
741 
742 	sg_init_table(iod->sg, blk_rq_nr_phys_segments(req));
743 	iod->nents = blk_rq_map_sg(q, req, iod->sg);
744 	if (!iod->nents)
745 		goto out;
746 
747 	ret = BLK_STS_RESOURCE;
748 
749 	if (is_pci_p2pdma_page(sg_page(iod->sg)))
750 		nr_mapped = pci_p2pdma_map_sg(dev->dev, iod->sg, iod->nents,
751 					  dma_dir);
752 	else
753 		nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents,
754 					     dma_dir,  DMA_ATTR_NO_WARN);
755 	if (!nr_mapped)
756 		goto out;
757 
758 	if (iod->use_sgl)
759 		ret = nvme_pci_setup_sgls(dev, req, &cmnd->rw, nr_mapped);
760 	else
761 		ret = nvme_pci_setup_prps(dev, req, &cmnd->rw);
762 
763 	if (ret != BLK_STS_OK)
764 		goto out_unmap;
765 
766 	ret = BLK_STS_IOERR;
767 	if (blk_integrity_rq(req)) {
768 		if (blk_rq_count_integrity_sg(q, req->bio) != 1)
769 			goto out_unmap;
770 
771 		sg_init_table(&iod->meta_sg, 1);
772 		if (blk_rq_map_integrity_sg(q, req->bio, &iod->meta_sg) != 1)
773 			goto out_unmap;
774 
775 		if (!dma_map_sg(dev->dev, &iod->meta_sg, 1, dma_dir))
776 			goto out_unmap;
777 
778 		cmnd->rw.metadata = cpu_to_le64(sg_dma_address(&iod->meta_sg));
779 	}
780 
781 	return BLK_STS_OK;
782 
783 out_unmap:
784 	dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
785 out:
786 	return ret;
787 }
788 
789 static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
790 {
791 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
792 	enum dma_data_direction dma_dir = rq_data_dir(req) ?
793 			DMA_TO_DEVICE : DMA_FROM_DEVICE;
794 
795 	if (iod->nents) {
796 		/* P2PDMA requests do not need to be unmapped */
797 		if (!is_pci_p2pdma_page(sg_page(iod->sg)))
798 			dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
799 
800 		if (blk_integrity_rq(req))
801 			dma_unmap_sg(dev->dev, &iod->meta_sg, 1, dma_dir);
802 	}
803 
804 	nvme_cleanup_cmd(req);
805 	nvme_free_iod(dev, req);
806 }
807 
808 /*
809  * NOTE: ns is NULL when called on the admin queue.
810  */
811 static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
812 			 const struct blk_mq_queue_data *bd)
813 {
814 	struct nvme_ns *ns = hctx->queue->queuedata;
815 	struct nvme_queue *nvmeq = hctx->driver_data;
816 	struct nvme_dev *dev = nvmeq->dev;
817 	struct request *req = bd->rq;
818 	struct nvme_command cmnd;
819 	blk_status_t ret;
820 
821 	/*
822 	 * We should not need to do this, but we're still using this to
823 	 * ensure we can drain requests on a dying queue.
824 	 */
825 	if (unlikely(nvmeq->cq_vector < 0))
826 		return BLK_STS_IOERR;
827 
828 	ret = nvme_setup_cmd(ns, req, &cmnd);
829 	if (ret)
830 		return ret;
831 
832 	ret = nvme_init_iod(req, dev);
833 	if (ret)
834 		goto out_free_cmd;
835 
836 	if (blk_rq_nr_phys_segments(req)) {
837 		ret = nvme_map_data(dev, req, &cmnd);
838 		if (ret)
839 			goto out_cleanup_iod;
840 	}
841 
842 	blk_mq_start_request(req);
843 	nvme_submit_cmd(nvmeq, &cmnd);
844 	return BLK_STS_OK;
845 out_cleanup_iod:
846 	nvme_free_iod(dev, req);
847 out_free_cmd:
848 	nvme_cleanup_cmd(req);
849 	return ret;
850 }
851 
852 static void nvme_pci_complete_rq(struct request *req)
853 {
854 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
855 
856 	nvme_unmap_data(iod->nvmeq->dev, req);
857 	nvme_complete_rq(req);
858 }
859 
860 /* We read the CQE phase first to check if the rest of the entry is valid */
861 static inline bool nvme_cqe_pending(struct nvme_queue *nvmeq)
862 {
863 	return (le16_to_cpu(nvmeq->cqes[nvmeq->cq_head].status) & 1) ==
864 			nvmeq->cq_phase;
865 }
866 
867 static inline void nvme_ring_cq_doorbell(struct nvme_queue *nvmeq)
868 {
869 	u16 head = nvmeq->cq_head;
870 
871 	if (nvme_dbbuf_update_and_check_event(head, nvmeq->dbbuf_cq_db,
872 					      nvmeq->dbbuf_cq_ei))
873 		writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
874 }
875 
876 static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx)
877 {
878 	volatile struct nvme_completion *cqe = &nvmeq->cqes[idx];
879 	struct request *req;
880 
881 	if (unlikely(cqe->command_id >= nvmeq->q_depth)) {
882 		dev_warn(nvmeq->dev->ctrl.device,
883 			"invalid id %d completed on queue %d\n",
884 			cqe->command_id, le16_to_cpu(cqe->sq_id));
885 		return;
886 	}
887 
888 	/*
889 	 * AEN requests are special as they don't time out and can
890 	 * survive any kind of queue freeze and often don't respond to
891 	 * aborts.  We don't even bother to allocate a struct request
892 	 * for them but rather special case them here.
893 	 */
894 	if (unlikely(nvmeq->qid == 0 &&
895 			cqe->command_id >= NVME_AQ_BLK_MQ_DEPTH)) {
896 		nvme_complete_async_event(&nvmeq->dev->ctrl,
897 				cqe->status, &cqe->result);
898 		return;
899 	}
900 
901 	req = blk_mq_tag_to_rq(*nvmeq->tags, cqe->command_id);
902 	nvme_end_request(req, cqe->status, cqe->result);
903 }
904 
905 static void nvme_complete_cqes(struct nvme_queue *nvmeq, u16 start, u16 end)
906 {
907 	while (start != end) {
908 		nvme_handle_cqe(nvmeq, start);
909 		if (++start == nvmeq->q_depth)
910 			start = 0;
911 	}
912 }
913 
914 static inline void nvme_update_cq_head(struct nvme_queue *nvmeq)
915 {
916 	if (++nvmeq->cq_head == nvmeq->q_depth) {
917 		nvmeq->cq_head = 0;
918 		nvmeq->cq_phase = !nvmeq->cq_phase;
919 	}
920 }
921 
922 static inline bool nvme_process_cq(struct nvme_queue *nvmeq, u16 *start,
923 		u16 *end, int tag)
924 {
925 	bool found = false;
926 
927 	*start = nvmeq->cq_head;
928 	while (!found && nvme_cqe_pending(nvmeq)) {
929 		if (nvmeq->cqes[nvmeq->cq_head].command_id == tag)
930 			found = true;
931 		nvme_update_cq_head(nvmeq);
932 	}
933 	*end = nvmeq->cq_head;
934 
935 	if (*start != *end)
936 		nvme_ring_cq_doorbell(nvmeq);
937 	return found;
938 }
939 
940 static irqreturn_t nvme_irq(int irq, void *data)
941 {
942 	struct nvme_queue *nvmeq = data;
943 	irqreturn_t ret = IRQ_NONE;
944 	u16 start, end;
945 
946 	spin_lock(&nvmeq->cq_lock);
947 	if (nvmeq->cq_head != nvmeq->last_cq_head)
948 		ret = IRQ_HANDLED;
949 	nvme_process_cq(nvmeq, &start, &end, -1);
950 	nvmeq->last_cq_head = nvmeq->cq_head;
951 	spin_unlock(&nvmeq->cq_lock);
952 
953 	if (start != end) {
954 		nvme_complete_cqes(nvmeq, start, end);
955 		return IRQ_HANDLED;
956 	}
957 
958 	return ret;
959 }
960 
961 static irqreturn_t nvme_irq_check(int irq, void *data)
962 {
963 	struct nvme_queue *nvmeq = data;
964 	if (nvme_cqe_pending(nvmeq))
965 		return IRQ_WAKE_THREAD;
966 	return IRQ_NONE;
967 }
968 
969 static int __nvme_poll(struct nvme_queue *nvmeq, unsigned int tag)
970 {
971 	u16 start, end;
972 	bool found;
973 
974 	if (!nvme_cqe_pending(nvmeq))
975 		return 0;
976 
977 	spin_lock_irq(&nvmeq->cq_lock);
978 	found = nvme_process_cq(nvmeq, &start, &end, tag);
979 	spin_unlock_irq(&nvmeq->cq_lock);
980 
981 	nvme_complete_cqes(nvmeq, start, end);
982 	return found;
983 }
984 
985 static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
986 {
987 	struct nvme_queue *nvmeq = hctx->driver_data;
988 
989 	return __nvme_poll(nvmeq, tag);
990 }
991 
992 static void nvme_pci_submit_async_event(struct nvme_ctrl *ctrl)
993 {
994 	struct nvme_dev *dev = to_nvme_dev(ctrl);
995 	struct nvme_queue *nvmeq = &dev->queues[0];
996 	struct nvme_command c;
997 
998 	memset(&c, 0, sizeof(c));
999 	c.common.opcode = nvme_admin_async_event;
1000 	c.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
1001 	nvme_submit_cmd(nvmeq, &c);
1002 }
1003 
1004 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
1005 {
1006 	struct nvme_command c;
1007 
1008 	memset(&c, 0, sizeof(c));
1009 	c.delete_queue.opcode = opcode;
1010 	c.delete_queue.qid = cpu_to_le16(id);
1011 
1012 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1013 }
1014 
1015 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
1016 		struct nvme_queue *nvmeq, s16 vector)
1017 {
1018 	struct nvme_command c;
1019 	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
1020 
1021 	/*
1022 	 * Note: we (ab)use the fact that the prp fields survive if no data
1023 	 * is attached to the request.
1024 	 */
1025 	memset(&c, 0, sizeof(c));
1026 	c.create_cq.opcode = nvme_admin_create_cq;
1027 	c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
1028 	c.create_cq.cqid = cpu_to_le16(qid);
1029 	c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
1030 	c.create_cq.cq_flags = cpu_to_le16(flags);
1031 	c.create_cq.irq_vector = cpu_to_le16(vector);
1032 
1033 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1034 }
1035 
1036 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
1037 						struct nvme_queue *nvmeq)
1038 {
1039 	struct nvme_ctrl *ctrl = &dev->ctrl;
1040 	struct nvme_command c;
1041 	int flags = NVME_QUEUE_PHYS_CONTIG;
1042 
1043 	/*
1044 	 * Some drives have a bug that auto-enables WRRU if MEDIUM isn't
1045 	 * set. Since URGENT priority is zeroes, it makes all queues
1046 	 * URGENT.
1047 	 */
1048 	if (ctrl->quirks & NVME_QUIRK_MEDIUM_PRIO_SQ)
1049 		flags |= NVME_SQ_PRIO_MEDIUM;
1050 
1051 	/*
1052 	 * Note: we (ab)use the fact that the prp fields survive if no data
1053 	 * is attached to the request.
1054 	 */
1055 	memset(&c, 0, sizeof(c));
1056 	c.create_sq.opcode = nvme_admin_create_sq;
1057 	c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
1058 	c.create_sq.sqid = cpu_to_le16(qid);
1059 	c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
1060 	c.create_sq.sq_flags = cpu_to_le16(flags);
1061 	c.create_sq.cqid = cpu_to_le16(qid);
1062 
1063 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1064 }
1065 
1066 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
1067 {
1068 	return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
1069 }
1070 
1071 static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
1072 {
1073 	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
1074 }
1075 
1076 static void abort_endio(struct request *req, blk_status_t error)
1077 {
1078 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
1079 	struct nvme_queue *nvmeq = iod->nvmeq;
1080 
1081 	dev_warn(nvmeq->dev->ctrl.device,
1082 		 "Abort status: 0x%x", nvme_req(req)->status);
1083 	atomic_inc(&nvmeq->dev->ctrl.abort_limit);
1084 	blk_mq_free_request(req);
1085 }
1086 
1087 static bool nvme_should_reset(struct nvme_dev *dev, u32 csts)
1088 {
1089 
1090 	/* If true, indicates loss of adapter communication, possibly by a
1091 	 * NVMe Subsystem reset.
1092 	 */
1093 	bool nssro = dev->subsystem && (csts & NVME_CSTS_NSSRO);
1094 
1095 	/* If there is a reset/reinit ongoing, we shouldn't reset again. */
1096 	switch (dev->ctrl.state) {
1097 	case NVME_CTRL_RESETTING:
1098 	case NVME_CTRL_CONNECTING:
1099 		return false;
1100 	default:
1101 		break;
1102 	}
1103 
1104 	/* We shouldn't reset unless the controller is on fatal error state
1105 	 * _or_ if we lost the communication with it.
1106 	 */
1107 	if (!(csts & NVME_CSTS_CFS) && !nssro)
1108 		return false;
1109 
1110 	return true;
1111 }
1112 
1113 static void nvme_warn_reset(struct nvme_dev *dev, u32 csts)
1114 {
1115 	/* Read a config register to help see what died. */
1116 	u16 pci_status;
1117 	int result;
1118 
1119 	result = pci_read_config_word(to_pci_dev(dev->dev), PCI_STATUS,
1120 				      &pci_status);
1121 	if (result == PCIBIOS_SUCCESSFUL)
1122 		dev_warn(dev->ctrl.device,
1123 			 "controller is down; will reset: CSTS=0x%x, PCI_STATUS=0x%hx\n",
1124 			 csts, pci_status);
1125 	else
1126 		dev_warn(dev->ctrl.device,
1127 			 "controller is down; will reset: CSTS=0x%x, PCI_STATUS read failed (%d)\n",
1128 			 csts, result);
1129 }
1130 
1131 static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
1132 {
1133 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
1134 	struct nvme_queue *nvmeq = iod->nvmeq;
1135 	struct nvme_dev *dev = nvmeq->dev;
1136 	struct request *abort_req;
1137 	struct nvme_command cmd;
1138 	u32 csts = readl(dev->bar + NVME_REG_CSTS);
1139 
1140 	/* If PCI error recovery process is happening, we cannot reset or
1141 	 * the recovery mechanism will surely fail.
1142 	 */
1143 	mb();
1144 	if (pci_channel_offline(to_pci_dev(dev->dev)))
1145 		return BLK_EH_RESET_TIMER;
1146 
1147 	/*
1148 	 * Reset immediately if the controller is failed
1149 	 */
1150 	if (nvme_should_reset(dev, csts)) {
1151 		nvme_warn_reset(dev, csts);
1152 		nvme_dev_disable(dev, false);
1153 		nvme_reset_ctrl(&dev->ctrl);
1154 		return BLK_EH_DONE;
1155 	}
1156 
1157 	/*
1158 	 * Did we miss an interrupt?
1159 	 */
1160 	if (__nvme_poll(nvmeq, req->tag)) {
1161 		dev_warn(dev->ctrl.device,
1162 			 "I/O %d QID %d timeout, completion polled\n",
1163 			 req->tag, nvmeq->qid);
1164 		return BLK_EH_DONE;
1165 	}
1166 
1167 	/*
1168 	 * Shutdown immediately if controller times out while starting. The
1169 	 * reset work will see the pci device disabled when it gets the forced
1170 	 * cancellation error. All outstanding requests are completed on
1171 	 * shutdown, so we return BLK_EH_DONE.
1172 	 */
1173 	switch (dev->ctrl.state) {
1174 	case NVME_CTRL_CONNECTING:
1175 	case NVME_CTRL_RESETTING:
1176 		dev_warn_ratelimited(dev->ctrl.device,
1177 			 "I/O %d QID %d timeout, disable controller\n",
1178 			 req->tag, nvmeq->qid);
1179 		nvme_dev_disable(dev, false);
1180 		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
1181 		return BLK_EH_DONE;
1182 	default:
1183 		break;
1184 	}
1185 
1186 	/*
1187  	 * Shutdown the controller immediately and schedule a reset if the
1188  	 * command was already aborted once before and still hasn't been
1189  	 * returned to the driver, or if this is the admin queue.
1190 	 */
1191 	if (!nvmeq->qid || iod->aborted) {
1192 		dev_warn(dev->ctrl.device,
1193 			 "I/O %d QID %d timeout, reset controller\n",
1194 			 req->tag, nvmeq->qid);
1195 		nvme_dev_disable(dev, false);
1196 		nvme_reset_ctrl(&dev->ctrl);
1197 
1198 		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
1199 		return BLK_EH_DONE;
1200 	}
1201 
1202 	if (atomic_dec_return(&dev->ctrl.abort_limit) < 0) {
1203 		atomic_inc(&dev->ctrl.abort_limit);
1204 		return BLK_EH_RESET_TIMER;
1205 	}
1206 	iod->aborted = 1;
1207 
1208 	memset(&cmd, 0, sizeof(cmd));
1209 	cmd.abort.opcode = nvme_admin_abort_cmd;
1210 	cmd.abort.cid = req->tag;
1211 	cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
1212 
1213 	dev_warn(nvmeq->dev->ctrl.device,
1214 		"I/O %d QID %d timeout, aborting\n",
1215 		 req->tag, nvmeq->qid);
1216 
1217 	abort_req = nvme_alloc_request(dev->ctrl.admin_q, &cmd,
1218 			BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
1219 	if (IS_ERR(abort_req)) {
1220 		atomic_inc(&dev->ctrl.abort_limit);
1221 		return BLK_EH_RESET_TIMER;
1222 	}
1223 
1224 	abort_req->timeout = ADMIN_TIMEOUT;
1225 	abort_req->end_io_data = NULL;
1226 	blk_execute_rq_nowait(abort_req->q, NULL, abort_req, 0, abort_endio);
1227 
1228 	/*
1229 	 * The aborted req will be completed on receiving the abort req.
1230 	 * We enable the timer again. If hit twice, it'll cause a device reset,
1231 	 * as the device then is in a faulty state.
1232 	 */
1233 	return BLK_EH_RESET_TIMER;
1234 }
1235 
1236 static void nvme_free_queue(struct nvme_queue *nvmeq)
1237 {
1238 	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
1239 				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
1240 
1241 	if (nvmeq->sq_cmds) {
1242 		if (nvmeq->sq_cmds_is_io)
1243 			pci_free_p2pmem(to_pci_dev(nvmeq->q_dmadev),
1244 					nvmeq->sq_cmds,
1245 					SQ_SIZE(nvmeq->q_depth));
1246 		else
1247 			dma_free_coherent(nvmeq->q_dmadev,
1248 					  SQ_SIZE(nvmeq->q_depth),
1249 					  nvmeq->sq_cmds,
1250 					  nvmeq->sq_dma_addr);
1251 	}
1252 }
1253 
1254 static void nvme_free_queues(struct nvme_dev *dev, int lowest)
1255 {
1256 	int i;
1257 
1258 	for (i = dev->ctrl.queue_count - 1; i >= lowest; i--) {
1259 		dev->ctrl.queue_count--;
1260 		nvme_free_queue(&dev->queues[i]);
1261 	}
1262 }
1263 
1264 /**
1265  * nvme_suspend_queue - put queue into suspended state
1266  * @nvmeq: queue to suspend
1267  */
1268 static int nvme_suspend_queue(struct nvme_queue *nvmeq)
1269 {
1270 	int vector;
1271 
1272 	spin_lock_irq(&nvmeq->cq_lock);
1273 	if (nvmeq->cq_vector == -1) {
1274 		spin_unlock_irq(&nvmeq->cq_lock);
1275 		return 1;
1276 	}
1277 	vector = nvmeq->cq_vector;
1278 	nvmeq->dev->online_queues--;
1279 	nvmeq->cq_vector = -1;
1280 	spin_unlock_irq(&nvmeq->cq_lock);
1281 
1282 	/*
1283 	 * Ensure that nvme_queue_rq() sees it ->cq_vector == -1 without
1284 	 * having to grab the lock.
1285 	 */
1286 	mb();
1287 
1288 	if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
1289 		blk_mq_quiesce_queue(nvmeq->dev->ctrl.admin_q);
1290 
1291 	pci_free_irq(to_pci_dev(nvmeq->dev->dev), vector, nvmeq);
1292 
1293 	return 0;
1294 }
1295 
1296 static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
1297 {
1298 	struct nvme_queue *nvmeq = &dev->queues[0];
1299 	u16 start, end;
1300 
1301 	if (shutdown)
1302 		nvme_shutdown_ctrl(&dev->ctrl);
1303 	else
1304 		nvme_disable_ctrl(&dev->ctrl, dev->ctrl.cap);
1305 
1306 	spin_lock_irq(&nvmeq->cq_lock);
1307 	nvme_process_cq(nvmeq, &start, &end, -1);
1308 	spin_unlock_irq(&nvmeq->cq_lock);
1309 
1310 	nvme_complete_cqes(nvmeq, start, end);
1311 }
1312 
1313 static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues,
1314 				int entry_size)
1315 {
1316 	int q_depth = dev->q_depth;
1317 	unsigned q_size_aligned = roundup(q_depth * entry_size,
1318 					  dev->ctrl.page_size);
1319 
1320 	if (q_size_aligned * nr_io_queues > dev->cmb_size) {
1321 		u64 mem_per_q = div_u64(dev->cmb_size, nr_io_queues);
1322 		mem_per_q = round_down(mem_per_q, dev->ctrl.page_size);
1323 		q_depth = div_u64(mem_per_q, entry_size);
1324 
1325 		/*
1326 		 * Ensure the reduced q_depth is above some threshold where it
1327 		 * would be better to map queues in system memory with the
1328 		 * original depth
1329 		 */
1330 		if (q_depth < 64)
1331 			return -ENOMEM;
1332 	}
1333 
1334 	return q_depth;
1335 }
1336 
1337 static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
1338 				int qid, int depth)
1339 {
1340 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1341 
1342 	if (qid && dev->cmb_use_sqes && (dev->cmbsz & NVME_CMBSZ_SQS)) {
1343 		nvmeq->sq_cmds = pci_alloc_p2pmem(pdev, SQ_SIZE(depth));
1344 		nvmeq->sq_dma_addr = pci_p2pmem_virt_to_bus(pdev,
1345 						nvmeq->sq_cmds);
1346 		nvmeq->sq_cmds_is_io = true;
1347 	}
1348 
1349 	if (!nvmeq->sq_cmds) {
1350 		nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(depth),
1351 					&nvmeq->sq_dma_addr, GFP_KERNEL);
1352 		nvmeq->sq_cmds_is_io = false;
1353 	}
1354 
1355 	if (!nvmeq->sq_cmds)
1356 		return -ENOMEM;
1357 	return 0;
1358 }
1359 
1360 static int nvme_alloc_queue(struct nvme_dev *dev, int qid, int depth)
1361 {
1362 	struct nvme_queue *nvmeq = &dev->queues[qid];
1363 
1364 	if (dev->ctrl.queue_count > qid)
1365 		return 0;
1366 
1367 	nvmeq->cqes = dma_zalloc_coherent(dev->dev, CQ_SIZE(depth),
1368 					  &nvmeq->cq_dma_addr, GFP_KERNEL);
1369 	if (!nvmeq->cqes)
1370 		goto free_nvmeq;
1371 
1372 	if (nvme_alloc_sq_cmds(dev, nvmeq, qid, depth))
1373 		goto free_cqdma;
1374 
1375 	nvmeq->q_dmadev = dev->dev;
1376 	nvmeq->dev = dev;
1377 	spin_lock_init(&nvmeq->sq_lock);
1378 	spin_lock_init(&nvmeq->cq_lock);
1379 	nvmeq->cq_head = 0;
1380 	nvmeq->cq_phase = 1;
1381 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1382 	nvmeq->q_depth = depth;
1383 	nvmeq->qid = qid;
1384 	nvmeq->cq_vector = -1;
1385 	dev->ctrl.queue_count++;
1386 
1387 	return 0;
1388 
1389  free_cqdma:
1390 	dma_free_coherent(dev->dev, CQ_SIZE(depth), (void *)nvmeq->cqes,
1391 							nvmeq->cq_dma_addr);
1392  free_nvmeq:
1393 	return -ENOMEM;
1394 }
1395 
1396 static int queue_request_irq(struct nvme_queue *nvmeq)
1397 {
1398 	struct pci_dev *pdev = to_pci_dev(nvmeq->dev->dev);
1399 	int nr = nvmeq->dev->ctrl.instance;
1400 
1401 	if (use_threaded_interrupts) {
1402 		return pci_request_irq(pdev, nvmeq->cq_vector, nvme_irq_check,
1403 				nvme_irq, nvmeq, "nvme%dq%d", nr, nvmeq->qid);
1404 	} else {
1405 		return pci_request_irq(pdev, nvmeq->cq_vector, nvme_irq,
1406 				NULL, nvmeq, "nvme%dq%d", nr, nvmeq->qid);
1407 	}
1408 }
1409 
1410 static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
1411 {
1412 	struct nvme_dev *dev = nvmeq->dev;
1413 
1414 	spin_lock_irq(&nvmeq->cq_lock);
1415 	nvmeq->sq_tail = 0;
1416 	nvmeq->cq_head = 0;
1417 	nvmeq->cq_phase = 1;
1418 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1419 	memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth));
1420 	nvme_dbbuf_init(dev, nvmeq, qid);
1421 	dev->online_queues++;
1422 	spin_unlock_irq(&nvmeq->cq_lock);
1423 }
1424 
1425 static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
1426 {
1427 	struct nvme_dev *dev = nvmeq->dev;
1428 	int result;
1429 	s16 vector;
1430 
1431 	/*
1432 	 * A queue's vector matches the queue identifier unless the controller
1433 	 * has only one vector available.
1434 	 */
1435 	vector = dev->num_vecs == 1 ? 0 : qid;
1436 	result = adapter_alloc_cq(dev, qid, nvmeq, vector);
1437 	if (result)
1438 		return result;
1439 
1440 	result = adapter_alloc_sq(dev, qid, nvmeq);
1441 	if (result < 0)
1442 		return result;
1443 	else if (result)
1444 		goto release_cq;
1445 
1446 	/*
1447 	 * Set cq_vector after alloc cq/sq, otherwise nvme_suspend_queue will
1448 	 * invoke free_irq for it and cause a 'Trying to free already-free IRQ
1449 	 * xxx' warning if the create CQ/SQ command times out.
1450 	 */
1451 	nvmeq->cq_vector = vector;
1452 	nvme_init_queue(nvmeq, qid);
1453 	result = queue_request_irq(nvmeq);
1454 	if (result < 0)
1455 		goto release_sq;
1456 
1457 	return result;
1458 
1459 release_sq:
1460 	nvmeq->cq_vector = -1;
1461 	dev->online_queues--;
1462 	adapter_delete_sq(dev, qid);
1463 release_cq:
1464 	adapter_delete_cq(dev, qid);
1465 	return result;
1466 }
1467 
1468 static const struct blk_mq_ops nvme_mq_admin_ops = {
1469 	.queue_rq	= nvme_queue_rq,
1470 	.complete	= nvme_pci_complete_rq,
1471 	.init_hctx	= nvme_admin_init_hctx,
1472 	.exit_hctx      = nvme_admin_exit_hctx,
1473 	.init_request	= nvme_init_request,
1474 	.timeout	= nvme_timeout,
1475 };
1476 
1477 static const struct blk_mq_ops nvme_mq_ops = {
1478 	.queue_rq	= nvme_queue_rq,
1479 	.complete	= nvme_pci_complete_rq,
1480 	.init_hctx	= nvme_init_hctx,
1481 	.init_request	= nvme_init_request,
1482 	.map_queues	= nvme_pci_map_queues,
1483 	.timeout	= nvme_timeout,
1484 	.poll		= nvme_poll,
1485 };
1486 
1487 static void nvme_dev_remove_admin(struct nvme_dev *dev)
1488 {
1489 	if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q)) {
1490 		/*
1491 		 * If the controller was reset during removal, it's possible
1492 		 * user requests may be waiting on a stopped queue. Start the
1493 		 * queue to flush these to completion.
1494 		 */
1495 		blk_mq_unquiesce_queue(dev->ctrl.admin_q);
1496 		blk_cleanup_queue(dev->ctrl.admin_q);
1497 		blk_mq_free_tag_set(&dev->admin_tagset);
1498 	}
1499 }
1500 
1501 static int nvme_alloc_admin_tags(struct nvme_dev *dev)
1502 {
1503 	if (!dev->ctrl.admin_q) {
1504 		dev->admin_tagset.ops = &nvme_mq_admin_ops;
1505 		dev->admin_tagset.nr_hw_queues = 1;
1506 
1507 		dev->admin_tagset.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
1508 		dev->admin_tagset.timeout = ADMIN_TIMEOUT;
1509 		dev->admin_tagset.numa_node = dev_to_node(dev->dev);
1510 		dev->admin_tagset.cmd_size = nvme_pci_cmd_size(dev, false);
1511 		dev->admin_tagset.flags = BLK_MQ_F_NO_SCHED;
1512 		dev->admin_tagset.driver_data = dev;
1513 
1514 		if (blk_mq_alloc_tag_set(&dev->admin_tagset))
1515 			return -ENOMEM;
1516 		dev->ctrl.admin_tagset = &dev->admin_tagset;
1517 
1518 		dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
1519 		if (IS_ERR(dev->ctrl.admin_q)) {
1520 			blk_mq_free_tag_set(&dev->admin_tagset);
1521 			return -ENOMEM;
1522 		}
1523 		if (!blk_get_queue(dev->ctrl.admin_q)) {
1524 			nvme_dev_remove_admin(dev);
1525 			dev->ctrl.admin_q = NULL;
1526 			return -ENODEV;
1527 		}
1528 	} else
1529 		blk_mq_unquiesce_queue(dev->ctrl.admin_q);
1530 
1531 	return 0;
1532 }
1533 
1534 static unsigned long db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
1535 {
1536 	return NVME_REG_DBS + ((nr_io_queues + 1) * 8 * dev->db_stride);
1537 }
1538 
1539 static int nvme_remap_bar(struct nvme_dev *dev, unsigned long size)
1540 {
1541 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1542 
1543 	if (size <= dev->bar_mapped_size)
1544 		return 0;
1545 	if (size > pci_resource_len(pdev, 0))
1546 		return -ENOMEM;
1547 	if (dev->bar)
1548 		iounmap(dev->bar);
1549 	dev->bar = ioremap(pci_resource_start(pdev, 0), size);
1550 	if (!dev->bar) {
1551 		dev->bar_mapped_size = 0;
1552 		return -ENOMEM;
1553 	}
1554 	dev->bar_mapped_size = size;
1555 	dev->dbs = dev->bar + NVME_REG_DBS;
1556 
1557 	return 0;
1558 }
1559 
1560 static int nvme_pci_configure_admin_queue(struct nvme_dev *dev)
1561 {
1562 	int result;
1563 	u32 aqa;
1564 	struct nvme_queue *nvmeq;
1565 
1566 	result = nvme_remap_bar(dev, db_bar_size(dev, 0));
1567 	if (result < 0)
1568 		return result;
1569 
1570 	dev->subsystem = readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 1, 0) ?
1571 				NVME_CAP_NSSRC(dev->ctrl.cap) : 0;
1572 
1573 	if (dev->subsystem &&
1574 	    (readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_NSSRO))
1575 		writel(NVME_CSTS_NSSRO, dev->bar + NVME_REG_CSTS);
1576 
1577 	result = nvme_disable_ctrl(&dev->ctrl, dev->ctrl.cap);
1578 	if (result < 0)
1579 		return result;
1580 
1581 	result = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH);
1582 	if (result)
1583 		return result;
1584 
1585 	nvmeq = &dev->queues[0];
1586 	aqa = nvmeq->q_depth - 1;
1587 	aqa |= aqa << 16;
1588 
1589 	writel(aqa, dev->bar + NVME_REG_AQA);
1590 	lo_hi_writeq(nvmeq->sq_dma_addr, dev->bar + NVME_REG_ASQ);
1591 	lo_hi_writeq(nvmeq->cq_dma_addr, dev->bar + NVME_REG_ACQ);
1592 
1593 	result = nvme_enable_ctrl(&dev->ctrl, dev->ctrl.cap);
1594 	if (result)
1595 		return result;
1596 
1597 	nvmeq->cq_vector = 0;
1598 	nvme_init_queue(nvmeq, 0);
1599 	result = queue_request_irq(nvmeq);
1600 	if (result) {
1601 		nvmeq->cq_vector = -1;
1602 		return result;
1603 	}
1604 
1605 	return result;
1606 }
1607 
1608 static int nvme_create_io_queues(struct nvme_dev *dev)
1609 {
1610 	unsigned i, max;
1611 	int ret = 0;
1612 
1613 	for (i = dev->ctrl.queue_count; i <= dev->max_qid; i++) {
1614 		if (nvme_alloc_queue(dev, i, dev->q_depth)) {
1615 			ret = -ENOMEM;
1616 			break;
1617 		}
1618 	}
1619 
1620 	max = min(dev->max_qid, dev->ctrl.queue_count - 1);
1621 	for (i = dev->online_queues; i <= max; i++) {
1622 		ret = nvme_create_queue(&dev->queues[i], i);
1623 		if (ret)
1624 			break;
1625 	}
1626 
1627 	/*
1628 	 * Ignore failing Create SQ/CQ commands, we can continue with less
1629 	 * than the desired amount of queues, and even a controller without
1630 	 * I/O queues can still be used to issue admin commands.  This might
1631 	 * be useful to upgrade a buggy firmware for example.
1632 	 */
1633 	return ret >= 0 ? 0 : ret;
1634 }
1635 
1636 static ssize_t nvme_cmb_show(struct device *dev,
1637 			     struct device_attribute *attr,
1638 			     char *buf)
1639 {
1640 	struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
1641 
1642 	return scnprintf(buf, PAGE_SIZE, "cmbloc : x%08x\ncmbsz  : x%08x\n",
1643 		       ndev->cmbloc, ndev->cmbsz);
1644 }
1645 static DEVICE_ATTR(cmb, S_IRUGO, nvme_cmb_show, NULL);
1646 
1647 static u64 nvme_cmb_size_unit(struct nvme_dev *dev)
1648 {
1649 	u8 szu = (dev->cmbsz >> NVME_CMBSZ_SZU_SHIFT) & NVME_CMBSZ_SZU_MASK;
1650 
1651 	return 1ULL << (12 + 4 * szu);
1652 }
1653 
1654 static u32 nvme_cmb_size(struct nvme_dev *dev)
1655 {
1656 	return (dev->cmbsz >> NVME_CMBSZ_SZ_SHIFT) & NVME_CMBSZ_SZ_MASK;
1657 }
1658 
1659 static void nvme_map_cmb(struct nvme_dev *dev)
1660 {
1661 	u64 size, offset;
1662 	resource_size_t bar_size;
1663 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1664 	int bar;
1665 
1666 	if (dev->cmb_size)
1667 		return;
1668 
1669 	dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
1670 	if (!dev->cmbsz)
1671 		return;
1672 	dev->cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
1673 
1674 	size = nvme_cmb_size_unit(dev) * nvme_cmb_size(dev);
1675 	offset = nvme_cmb_size_unit(dev) * NVME_CMB_OFST(dev->cmbloc);
1676 	bar = NVME_CMB_BIR(dev->cmbloc);
1677 	bar_size = pci_resource_len(pdev, bar);
1678 
1679 	if (offset > bar_size)
1680 		return;
1681 
1682 	/*
1683 	 * Controllers may support a CMB size larger than their BAR,
1684 	 * for example, due to being behind a bridge. Reduce the CMB to
1685 	 * the reported size of the BAR
1686 	 */
1687 	if (size > bar_size - offset)
1688 		size = bar_size - offset;
1689 
1690 	if (pci_p2pdma_add_resource(pdev, bar, size, offset)) {
1691 		dev_warn(dev->ctrl.device,
1692 			 "failed to register the CMB\n");
1693 		return;
1694 	}
1695 
1696 	dev->cmb_size = size;
1697 	dev->cmb_use_sqes = use_cmb_sqes && (dev->cmbsz & NVME_CMBSZ_SQS);
1698 
1699 	if ((dev->cmbsz & (NVME_CMBSZ_WDS | NVME_CMBSZ_RDS)) ==
1700 			(NVME_CMBSZ_WDS | NVME_CMBSZ_RDS))
1701 		pci_p2pmem_publish(pdev, true);
1702 
1703 	if (sysfs_add_file_to_group(&dev->ctrl.device->kobj,
1704 				    &dev_attr_cmb.attr, NULL))
1705 		dev_warn(dev->ctrl.device,
1706 			 "failed to add sysfs attribute for CMB\n");
1707 }
1708 
1709 static inline void nvme_release_cmb(struct nvme_dev *dev)
1710 {
1711 	if (dev->cmb_size) {
1712 		sysfs_remove_file_from_group(&dev->ctrl.device->kobj,
1713 					     &dev_attr_cmb.attr, NULL);
1714 		dev->cmb_size = 0;
1715 	}
1716 }
1717 
1718 static int nvme_set_host_mem(struct nvme_dev *dev, u32 bits)
1719 {
1720 	u64 dma_addr = dev->host_mem_descs_dma;
1721 	struct nvme_command c;
1722 	int ret;
1723 
1724 	memset(&c, 0, sizeof(c));
1725 	c.features.opcode	= nvme_admin_set_features;
1726 	c.features.fid		= cpu_to_le32(NVME_FEAT_HOST_MEM_BUF);
1727 	c.features.dword11	= cpu_to_le32(bits);
1728 	c.features.dword12	= cpu_to_le32(dev->host_mem_size >>
1729 					      ilog2(dev->ctrl.page_size));
1730 	c.features.dword13	= cpu_to_le32(lower_32_bits(dma_addr));
1731 	c.features.dword14	= cpu_to_le32(upper_32_bits(dma_addr));
1732 	c.features.dword15	= cpu_to_le32(dev->nr_host_mem_descs);
1733 
1734 	ret = nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1735 	if (ret) {
1736 		dev_warn(dev->ctrl.device,
1737 			 "failed to set host mem (err %d, flags %#x).\n",
1738 			 ret, bits);
1739 	}
1740 	return ret;
1741 }
1742 
1743 static void nvme_free_host_mem(struct nvme_dev *dev)
1744 {
1745 	int i;
1746 
1747 	for (i = 0; i < dev->nr_host_mem_descs; i++) {
1748 		struct nvme_host_mem_buf_desc *desc = &dev->host_mem_descs[i];
1749 		size_t size = le32_to_cpu(desc->size) * dev->ctrl.page_size;
1750 
1751 		dma_free_coherent(dev->dev, size, dev->host_mem_desc_bufs[i],
1752 				le64_to_cpu(desc->addr));
1753 	}
1754 
1755 	kfree(dev->host_mem_desc_bufs);
1756 	dev->host_mem_desc_bufs = NULL;
1757 	dma_free_coherent(dev->dev,
1758 			dev->nr_host_mem_descs * sizeof(*dev->host_mem_descs),
1759 			dev->host_mem_descs, dev->host_mem_descs_dma);
1760 	dev->host_mem_descs = NULL;
1761 	dev->nr_host_mem_descs = 0;
1762 }
1763 
1764 static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred,
1765 		u32 chunk_size)
1766 {
1767 	struct nvme_host_mem_buf_desc *descs;
1768 	u32 max_entries, len;
1769 	dma_addr_t descs_dma;
1770 	int i = 0;
1771 	void **bufs;
1772 	u64 size, tmp;
1773 
1774 	tmp = (preferred + chunk_size - 1);
1775 	do_div(tmp, chunk_size);
1776 	max_entries = tmp;
1777 
1778 	if (dev->ctrl.hmmaxd && dev->ctrl.hmmaxd < max_entries)
1779 		max_entries = dev->ctrl.hmmaxd;
1780 
1781 	descs = dma_zalloc_coherent(dev->dev, max_entries * sizeof(*descs),
1782 			&descs_dma, GFP_KERNEL);
1783 	if (!descs)
1784 		goto out;
1785 
1786 	bufs = kcalloc(max_entries, sizeof(*bufs), GFP_KERNEL);
1787 	if (!bufs)
1788 		goto out_free_descs;
1789 
1790 	for (size = 0; size < preferred && i < max_entries; size += len) {
1791 		dma_addr_t dma_addr;
1792 
1793 		len = min_t(u64, chunk_size, preferred - size);
1794 		bufs[i] = dma_alloc_attrs(dev->dev, len, &dma_addr, GFP_KERNEL,
1795 				DMA_ATTR_NO_KERNEL_MAPPING | DMA_ATTR_NO_WARN);
1796 		if (!bufs[i])
1797 			break;
1798 
1799 		descs[i].addr = cpu_to_le64(dma_addr);
1800 		descs[i].size = cpu_to_le32(len / dev->ctrl.page_size);
1801 		i++;
1802 	}
1803 
1804 	if (!size)
1805 		goto out_free_bufs;
1806 
1807 	dev->nr_host_mem_descs = i;
1808 	dev->host_mem_size = size;
1809 	dev->host_mem_descs = descs;
1810 	dev->host_mem_descs_dma = descs_dma;
1811 	dev->host_mem_desc_bufs = bufs;
1812 	return 0;
1813 
1814 out_free_bufs:
1815 	while (--i >= 0) {
1816 		size_t size = le32_to_cpu(descs[i].size) * dev->ctrl.page_size;
1817 
1818 		dma_free_coherent(dev->dev, size, bufs[i],
1819 				le64_to_cpu(descs[i].addr));
1820 	}
1821 
1822 	kfree(bufs);
1823 out_free_descs:
1824 	dma_free_coherent(dev->dev, max_entries * sizeof(*descs), descs,
1825 			descs_dma);
1826 out:
1827 	dev->host_mem_descs = NULL;
1828 	return -ENOMEM;
1829 }
1830 
1831 static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred)
1832 {
1833 	u32 chunk_size;
1834 
1835 	/* start big and work our way down */
1836 	for (chunk_size = min_t(u64, preferred, PAGE_SIZE * MAX_ORDER_NR_PAGES);
1837 	     chunk_size >= max_t(u32, dev->ctrl.hmminds * 4096, PAGE_SIZE * 2);
1838 	     chunk_size /= 2) {
1839 		if (!__nvme_alloc_host_mem(dev, preferred, chunk_size)) {
1840 			if (!min || dev->host_mem_size >= min)
1841 				return 0;
1842 			nvme_free_host_mem(dev);
1843 		}
1844 	}
1845 
1846 	return -ENOMEM;
1847 }
1848 
1849 static int nvme_setup_host_mem(struct nvme_dev *dev)
1850 {
1851 	u64 max = (u64)max_host_mem_size_mb * SZ_1M;
1852 	u64 preferred = (u64)dev->ctrl.hmpre * 4096;
1853 	u64 min = (u64)dev->ctrl.hmmin * 4096;
1854 	u32 enable_bits = NVME_HOST_MEM_ENABLE;
1855 	int ret;
1856 
1857 	preferred = min(preferred, max);
1858 	if (min > max) {
1859 		dev_warn(dev->ctrl.device,
1860 			"min host memory (%lld MiB) above limit (%d MiB).\n",
1861 			min >> ilog2(SZ_1M), max_host_mem_size_mb);
1862 		nvme_free_host_mem(dev);
1863 		return 0;
1864 	}
1865 
1866 	/*
1867 	 * If we already have a buffer allocated check if we can reuse it.
1868 	 */
1869 	if (dev->host_mem_descs) {
1870 		if (dev->host_mem_size >= min)
1871 			enable_bits |= NVME_HOST_MEM_RETURN;
1872 		else
1873 			nvme_free_host_mem(dev);
1874 	}
1875 
1876 	if (!dev->host_mem_descs) {
1877 		if (nvme_alloc_host_mem(dev, min, preferred)) {
1878 			dev_warn(dev->ctrl.device,
1879 				"failed to allocate host memory buffer.\n");
1880 			return 0; /* controller must work without HMB */
1881 		}
1882 
1883 		dev_info(dev->ctrl.device,
1884 			"allocated %lld MiB host memory buffer.\n",
1885 			dev->host_mem_size >> ilog2(SZ_1M));
1886 	}
1887 
1888 	ret = nvme_set_host_mem(dev, enable_bits);
1889 	if (ret)
1890 		nvme_free_host_mem(dev);
1891 	return ret;
1892 }
1893 
1894 static int nvme_setup_io_queues(struct nvme_dev *dev)
1895 {
1896 	struct nvme_queue *adminq = &dev->queues[0];
1897 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1898 	int result, nr_io_queues;
1899 	unsigned long size;
1900 
1901 	struct irq_affinity affd = {
1902 		.pre_vectors = 1
1903 	};
1904 
1905 	nr_io_queues = num_possible_cpus();
1906 	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
1907 	if (result < 0)
1908 		return result;
1909 
1910 	if (nr_io_queues == 0)
1911 		return 0;
1912 
1913 	if (dev->cmb_use_sqes) {
1914 		result = nvme_cmb_qdepth(dev, nr_io_queues,
1915 				sizeof(struct nvme_command));
1916 		if (result > 0)
1917 			dev->q_depth = result;
1918 		else
1919 			dev->cmb_use_sqes = false;
1920 	}
1921 
1922 	do {
1923 		size = db_bar_size(dev, nr_io_queues);
1924 		result = nvme_remap_bar(dev, size);
1925 		if (!result)
1926 			break;
1927 		if (!--nr_io_queues)
1928 			return -ENOMEM;
1929 	} while (1);
1930 	adminq->q_db = dev->dbs;
1931 
1932 	/* Deregister the admin queue's interrupt */
1933 	pci_free_irq(pdev, 0, adminq);
1934 
1935 	/*
1936 	 * If we enable msix early due to not intx, disable it again before
1937 	 * setting up the full range we need.
1938 	 */
1939 	pci_free_irq_vectors(pdev);
1940 	result = pci_alloc_irq_vectors_affinity(pdev, 1, nr_io_queues + 1,
1941 			PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
1942 	if (result <= 0)
1943 		return -EIO;
1944 	dev->num_vecs = result;
1945 	dev->max_qid = max(result - 1, 1);
1946 
1947 	/*
1948 	 * Should investigate if there's a performance win from allocating
1949 	 * more queues than interrupt vectors; it might allow the submission
1950 	 * path to scale better, even if the receive path is limited by the
1951 	 * number of interrupts.
1952 	 */
1953 
1954 	result = queue_request_irq(adminq);
1955 	if (result) {
1956 		adminq->cq_vector = -1;
1957 		return result;
1958 	}
1959 	return nvme_create_io_queues(dev);
1960 }
1961 
1962 static void nvme_del_queue_end(struct request *req, blk_status_t error)
1963 {
1964 	struct nvme_queue *nvmeq = req->end_io_data;
1965 
1966 	blk_mq_free_request(req);
1967 	complete(&nvmeq->dev->ioq_wait);
1968 }
1969 
1970 static void nvme_del_cq_end(struct request *req, blk_status_t error)
1971 {
1972 	struct nvme_queue *nvmeq = req->end_io_data;
1973 	u16 start, end;
1974 
1975 	if (!error) {
1976 		unsigned long flags;
1977 
1978 		spin_lock_irqsave(&nvmeq->cq_lock, flags);
1979 		nvme_process_cq(nvmeq, &start, &end, -1);
1980 		spin_unlock_irqrestore(&nvmeq->cq_lock, flags);
1981 
1982 		nvme_complete_cqes(nvmeq, start, end);
1983 	}
1984 
1985 	nvme_del_queue_end(req, error);
1986 }
1987 
1988 static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
1989 {
1990 	struct request_queue *q = nvmeq->dev->ctrl.admin_q;
1991 	struct request *req;
1992 	struct nvme_command cmd;
1993 
1994 	memset(&cmd, 0, sizeof(cmd));
1995 	cmd.delete_queue.opcode = opcode;
1996 	cmd.delete_queue.qid = cpu_to_le16(nvmeq->qid);
1997 
1998 	req = nvme_alloc_request(q, &cmd, BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
1999 	if (IS_ERR(req))
2000 		return PTR_ERR(req);
2001 
2002 	req->timeout = ADMIN_TIMEOUT;
2003 	req->end_io_data = nvmeq;
2004 
2005 	blk_execute_rq_nowait(q, NULL, req, false,
2006 			opcode == nvme_admin_delete_cq ?
2007 				nvme_del_cq_end : nvme_del_queue_end);
2008 	return 0;
2009 }
2010 
2011 static void nvme_disable_io_queues(struct nvme_dev *dev)
2012 {
2013 	int pass, queues = dev->online_queues - 1;
2014 	unsigned long timeout;
2015 	u8 opcode = nvme_admin_delete_sq;
2016 
2017 	for (pass = 0; pass < 2; pass++) {
2018 		int sent = 0, i = queues;
2019 
2020 		reinit_completion(&dev->ioq_wait);
2021  retry:
2022 		timeout = ADMIN_TIMEOUT;
2023 		for (; i > 0; i--, sent++)
2024 			if (nvme_delete_queue(&dev->queues[i], opcode))
2025 				break;
2026 
2027 		while (sent--) {
2028 			timeout = wait_for_completion_io_timeout(&dev->ioq_wait, timeout);
2029 			if (timeout == 0)
2030 				return;
2031 			if (i)
2032 				goto retry;
2033 		}
2034 		opcode = nvme_admin_delete_cq;
2035 	}
2036 }
2037 
2038 /*
2039  * return error value only when tagset allocation failed
2040  */
2041 static int nvme_dev_add(struct nvme_dev *dev)
2042 {
2043 	int ret;
2044 
2045 	if (!dev->ctrl.tagset) {
2046 		dev->tagset.ops = &nvme_mq_ops;
2047 		dev->tagset.nr_hw_queues = dev->online_queues - 1;
2048 		dev->tagset.timeout = NVME_IO_TIMEOUT;
2049 		dev->tagset.numa_node = dev_to_node(dev->dev);
2050 		dev->tagset.queue_depth =
2051 				min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH) - 1;
2052 		dev->tagset.cmd_size = nvme_pci_cmd_size(dev, false);
2053 		if ((dev->ctrl.sgls & ((1 << 0) | (1 << 1))) && sgl_threshold) {
2054 			dev->tagset.cmd_size = max(dev->tagset.cmd_size,
2055 					nvme_pci_cmd_size(dev, true));
2056 		}
2057 		dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
2058 		dev->tagset.driver_data = dev;
2059 
2060 		ret = blk_mq_alloc_tag_set(&dev->tagset);
2061 		if (ret) {
2062 			dev_warn(dev->ctrl.device,
2063 				"IO queues tagset allocation failed %d\n", ret);
2064 			return ret;
2065 		}
2066 		dev->ctrl.tagset = &dev->tagset;
2067 
2068 		nvme_dbbuf_set(dev);
2069 	} else {
2070 		blk_mq_update_nr_hw_queues(&dev->tagset, dev->online_queues - 1);
2071 
2072 		/* Free previously allocated queues that are no longer usable */
2073 		nvme_free_queues(dev, dev->online_queues);
2074 	}
2075 
2076 	return 0;
2077 }
2078 
2079 static int nvme_pci_enable(struct nvme_dev *dev)
2080 {
2081 	int result = -ENOMEM;
2082 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2083 
2084 	if (pci_enable_device_mem(pdev))
2085 		return result;
2086 
2087 	pci_set_master(pdev);
2088 
2089 	if (dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(64)) &&
2090 	    dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(32)))
2091 		goto disable;
2092 
2093 	if (readl(dev->bar + NVME_REG_CSTS) == -1) {
2094 		result = -ENODEV;
2095 		goto disable;
2096 	}
2097 
2098 	/*
2099 	 * Some devices and/or platforms don't advertise or work with INTx
2100 	 * interrupts. Pre-enable a single MSIX or MSI vec for setup. We'll
2101 	 * adjust this later.
2102 	 */
2103 	result = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
2104 	if (result < 0)
2105 		return result;
2106 
2107 	dev->ctrl.cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
2108 
2109 	dev->q_depth = min_t(int, NVME_CAP_MQES(dev->ctrl.cap) + 1,
2110 				io_queue_depth);
2111 	dev->db_stride = 1 << NVME_CAP_STRIDE(dev->ctrl.cap);
2112 	dev->dbs = dev->bar + 4096;
2113 
2114 	/*
2115 	 * Temporary fix for the Apple controller found in the MacBook8,1 and
2116 	 * some MacBook7,1 to avoid controller resets and data loss.
2117 	 */
2118 	if (pdev->vendor == PCI_VENDOR_ID_APPLE && pdev->device == 0x2001) {
2119 		dev->q_depth = 2;
2120 		dev_warn(dev->ctrl.device, "detected Apple NVMe controller, "
2121 			"set queue depth=%u to work around controller resets\n",
2122 			dev->q_depth);
2123 	} else if (pdev->vendor == PCI_VENDOR_ID_SAMSUNG &&
2124 		   (pdev->device == 0xa821 || pdev->device == 0xa822) &&
2125 		   NVME_CAP_MQES(dev->ctrl.cap) == 0) {
2126 		dev->q_depth = 64;
2127 		dev_err(dev->ctrl.device, "detected PM1725 NVMe controller, "
2128                         "set queue depth=%u\n", dev->q_depth);
2129 	}
2130 
2131 	nvme_map_cmb(dev);
2132 
2133 	pci_enable_pcie_error_reporting(pdev);
2134 	pci_save_state(pdev);
2135 	return 0;
2136 
2137  disable:
2138 	pci_disable_device(pdev);
2139 	return result;
2140 }
2141 
2142 static void nvme_dev_unmap(struct nvme_dev *dev)
2143 {
2144 	if (dev->bar)
2145 		iounmap(dev->bar);
2146 	pci_release_mem_regions(to_pci_dev(dev->dev));
2147 }
2148 
2149 static void nvme_pci_disable(struct nvme_dev *dev)
2150 {
2151 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2152 
2153 	pci_free_irq_vectors(pdev);
2154 
2155 	if (pci_is_enabled(pdev)) {
2156 		pci_disable_pcie_error_reporting(pdev);
2157 		pci_disable_device(pdev);
2158 	}
2159 }
2160 
2161 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
2162 {
2163 	int i;
2164 	bool dead = true;
2165 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2166 
2167 	mutex_lock(&dev->shutdown_lock);
2168 	if (pci_is_enabled(pdev)) {
2169 		u32 csts = readl(dev->bar + NVME_REG_CSTS);
2170 
2171 		if (dev->ctrl.state == NVME_CTRL_LIVE ||
2172 		    dev->ctrl.state == NVME_CTRL_RESETTING)
2173 			nvme_start_freeze(&dev->ctrl);
2174 		dead = !!((csts & NVME_CSTS_CFS) || !(csts & NVME_CSTS_RDY) ||
2175 			pdev->error_state  != pci_channel_io_normal);
2176 	}
2177 
2178 	/*
2179 	 * Give the controller a chance to complete all entered requests if
2180 	 * doing a safe shutdown.
2181 	 */
2182 	if (!dead) {
2183 		if (shutdown)
2184 			nvme_wait_freeze_timeout(&dev->ctrl, NVME_IO_TIMEOUT);
2185 	}
2186 
2187 	nvme_stop_queues(&dev->ctrl);
2188 
2189 	if (!dead && dev->ctrl.queue_count > 0) {
2190 		nvme_disable_io_queues(dev);
2191 		nvme_disable_admin_queue(dev, shutdown);
2192 	}
2193 	for (i = dev->ctrl.queue_count - 1; i >= 0; i--)
2194 		nvme_suspend_queue(&dev->queues[i]);
2195 
2196 	nvme_pci_disable(dev);
2197 
2198 	blk_mq_tagset_busy_iter(&dev->tagset, nvme_cancel_request, &dev->ctrl);
2199 	blk_mq_tagset_busy_iter(&dev->admin_tagset, nvme_cancel_request, &dev->ctrl);
2200 
2201 	/*
2202 	 * The driver will not be starting up queues again if shutting down so
2203 	 * must flush all entered requests to their failed completion to avoid
2204 	 * deadlocking blk-mq hot-cpu notifier.
2205 	 */
2206 	if (shutdown)
2207 		nvme_start_queues(&dev->ctrl);
2208 	mutex_unlock(&dev->shutdown_lock);
2209 }
2210 
2211 static int nvme_setup_prp_pools(struct nvme_dev *dev)
2212 {
2213 	dev->prp_page_pool = dma_pool_create("prp list page", dev->dev,
2214 						PAGE_SIZE, PAGE_SIZE, 0);
2215 	if (!dev->prp_page_pool)
2216 		return -ENOMEM;
2217 
2218 	/* Optimisation for I/Os between 4k and 128k */
2219 	dev->prp_small_pool = dma_pool_create("prp list 256", dev->dev,
2220 						256, 256, 0);
2221 	if (!dev->prp_small_pool) {
2222 		dma_pool_destroy(dev->prp_page_pool);
2223 		return -ENOMEM;
2224 	}
2225 	return 0;
2226 }
2227 
2228 static void nvme_release_prp_pools(struct nvme_dev *dev)
2229 {
2230 	dma_pool_destroy(dev->prp_page_pool);
2231 	dma_pool_destroy(dev->prp_small_pool);
2232 }
2233 
2234 static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
2235 {
2236 	struct nvme_dev *dev = to_nvme_dev(ctrl);
2237 
2238 	nvme_dbbuf_dma_free(dev);
2239 	put_device(dev->dev);
2240 	if (dev->tagset.tags)
2241 		blk_mq_free_tag_set(&dev->tagset);
2242 	if (dev->ctrl.admin_q)
2243 		blk_put_queue(dev->ctrl.admin_q);
2244 	kfree(dev->queues);
2245 	free_opal_dev(dev->ctrl.opal_dev);
2246 	mempool_destroy(dev->iod_mempool);
2247 	kfree(dev);
2248 }
2249 
2250 static void nvme_remove_dead_ctrl(struct nvme_dev *dev, int status)
2251 {
2252 	dev_warn(dev->ctrl.device, "Removing after probe failure status: %d\n", status);
2253 
2254 	nvme_get_ctrl(&dev->ctrl);
2255 	nvme_dev_disable(dev, false);
2256 	nvme_kill_queues(&dev->ctrl);
2257 	if (!queue_work(nvme_wq, &dev->remove_work))
2258 		nvme_put_ctrl(&dev->ctrl);
2259 }
2260 
2261 static void nvme_reset_work(struct work_struct *work)
2262 {
2263 	struct nvme_dev *dev =
2264 		container_of(work, struct nvme_dev, ctrl.reset_work);
2265 	bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL);
2266 	int result = -ENODEV;
2267 	enum nvme_ctrl_state new_state = NVME_CTRL_LIVE;
2268 
2269 	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING))
2270 		goto out;
2271 
2272 	/*
2273 	 * If we're called to reset a live controller first shut it down before
2274 	 * moving on.
2275 	 */
2276 	if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
2277 		nvme_dev_disable(dev, false);
2278 
2279 	/*
2280 	 * Introduce CONNECTING state from nvme-fc/rdma transports to mark the
2281 	 * initializing procedure here.
2282 	 */
2283 	if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_CONNECTING)) {
2284 		dev_warn(dev->ctrl.device,
2285 			"failed to mark controller CONNECTING\n");
2286 		goto out;
2287 	}
2288 
2289 	result = nvme_pci_enable(dev);
2290 	if (result)
2291 		goto out;
2292 
2293 	result = nvme_pci_configure_admin_queue(dev);
2294 	if (result)
2295 		goto out;
2296 
2297 	result = nvme_alloc_admin_tags(dev);
2298 	if (result)
2299 		goto out;
2300 
2301 	/*
2302 	 * Limit the max command size to prevent iod->sg allocations going
2303 	 * over a single page.
2304 	 */
2305 	dev->ctrl.max_hw_sectors = NVME_MAX_KB_SZ << 1;
2306 	dev->ctrl.max_segments = NVME_MAX_SEGS;
2307 
2308 	result = nvme_init_identify(&dev->ctrl);
2309 	if (result)
2310 		goto out;
2311 
2312 	if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
2313 		if (!dev->ctrl.opal_dev)
2314 			dev->ctrl.opal_dev =
2315 				init_opal_dev(&dev->ctrl, &nvme_sec_submit);
2316 		else if (was_suspend)
2317 			opal_unlock_from_suspend(dev->ctrl.opal_dev);
2318 	} else {
2319 		free_opal_dev(dev->ctrl.opal_dev);
2320 		dev->ctrl.opal_dev = NULL;
2321 	}
2322 
2323 	if (dev->ctrl.oacs & NVME_CTRL_OACS_DBBUF_SUPP) {
2324 		result = nvme_dbbuf_dma_alloc(dev);
2325 		if (result)
2326 			dev_warn(dev->dev,
2327 				 "unable to allocate dma for dbbuf\n");
2328 	}
2329 
2330 	if (dev->ctrl.hmpre) {
2331 		result = nvme_setup_host_mem(dev);
2332 		if (result < 0)
2333 			goto out;
2334 	}
2335 
2336 	result = nvme_setup_io_queues(dev);
2337 	if (result)
2338 		goto out;
2339 
2340 	/*
2341 	 * Keep the controller around but remove all namespaces if we don't have
2342 	 * any working I/O queue.
2343 	 */
2344 	if (dev->online_queues < 2) {
2345 		dev_warn(dev->ctrl.device, "IO queues not created\n");
2346 		nvme_kill_queues(&dev->ctrl);
2347 		nvme_remove_namespaces(&dev->ctrl);
2348 		new_state = NVME_CTRL_ADMIN_ONLY;
2349 	} else {
2350 		nvme_start_queues(&dev->ctrl);
2351 		nvme_wait_freeze(&dev->ctrl);
2352 		/* hit this only when allocate tagset fails */
2353 		if (nvme_dev_add(dev))
2354 			new_state = NVME_CTRL_ADMIN_ONLY;
2355 		nvme_unfreeze(&dev->ctrl);
2356 	}
2357 
2358 	/*
2359 	 * If only admin queue live, keep it to do further investigation or
2360 	 * recovery.
2361 	 */
2362 	if (!nvme_change_ctrl_state(&dev->ctrl, new_state)) {
2363 		dev_warn(dev->ctrl.device,
2364 			"failed to mark controller state %d\n", new_state);
2365 		goto out;
2366 	}
2367 
2368 	nvme_start_ctrl(&dev->ctrl);
2369 	return;
2370 
2371  out:
2372 	nvme_remove_dead_ctrl(dev, result);
2373 }
2374 
2375 static void nvme_remove_dead_ctrl_work(struct work_struct *work)
2376 {
2377 	struct nvme_dev *dev = container_of(work, struct nvme_dev, remove_work);
2378 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2379 
2380 	if (pci_get_drvdata(pdev))
2381 		device_release_driver(&pdev->dev);
2382 	nvme_put_ctrl(&dev->ctrl);
2383 }
2384 
2385 static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
2386 {
2387 	*val = readl(to_nvme_dev(ctrl)->bar + off);
2388 	return 0;
2389 }
2390 
2391 static int nvme_pci_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
2392 {
2393 	writel(val, to_nvme_dev(ctrl)->bar + off);
2394 	return 0;
2395 }
2396 
2397 static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
2398 {
2399 	*val = readq(to_nvme_dev(ctrl)->bar + off);
2400 	return 0;
2401 }
2402 
2403 static int nvme_pci_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
2404 {
2405 	struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev);
2406 
2407 	return snprintf(buf, size, "%s", dev_name(&pdev->dev));
2408 }
2409 
2410 static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
2411 	.name			= "pcie",
2412 	.module			= THIS_MODULE,
2413 	.flags			= NVME_F_METADATA_SUPPORTED |
2414 				  NVME_F_PCI_P2PDMA,
2415 	.reg_read32		= nvme_pci_reg_read32,
2416 	.reg_write32		= nvme_pci_reg_write32,
2417 	.reg_read64		= nvme_pci_reg_read64,
2418 	.free_ctrl		= nvme_pci_free_ctrl,
2419 	.submit_async_event	= nvme_pci_submit_async_event,
2420 	.get_address		= nvme_pci_get_address,
2421 };
2422 
2423 static int nvme_dev_map(struct nvme_dev *dev)
2424 {
2425 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2426 
2427 	if (pci_request_mem_regions(pdev, "nvme"))
2428 		return -ENODEV;
2429 
2430 	if (nvme_remap_bar(dev, NVME_REG_DBS + 4096))
2431 		goto release;
2432 
2433 	return 0;
2434   release:
2435 	pci_release_mem_regions(pdev);
2436 	return -ENODEV;
2437 }
2438 
2439 static unsigned long check_vendor_combination_bug(struct pci_dev *pdev)
2440 {
2441 	if (pdev->vendor == 0x144d && pdev->device == 0xa802) {
2442 		/*
2443 		 * Several Samsung devices seem to drop off the PCIe bus
2444 		 * randomly when APST is on and uses the deepest sleep state.
2445 		 * This has been observed on a Samsung "SM951 NVMe SAMSUNG
2446 		 * 256GB", a "PM951 NVMe SAMSUNG 512GB", and a "Samsung SSD
2447 		 * 950 PRO 256GB", but it seems to be restricted to two Dell
2448 		 * laptops.
2449 		 */
2450 		if (dmi_match(DMI_SYS_VENDOR, "Dell Inc.") &&
2451 		    (dmi_match(DMI_PRODUCT_NAME, "XPS 15 9550") ||
2452 		     dmi_match(DMI_PRODUCT_NAME, "Precision 5510")))
2453 			return NVME_QUIRK_NO_DEEPEST_PS;
2454 	} else if (pdev->vendor == 0x144d && pdev->device == 0xa804) {
2455 		/*
2456 		 * Samsung SSD 960 EVO drops off the PCIe bus after system
2457 		 * suspend on a Ryzen board, ASUS PRIME B350M-A, as well as
2458 		 * within few minutes after bootup on a Coffee Lake board -
2459 		 * ASUS PRIME Z370-A
2460 		 */
2461 		if (dmi_match(DMI_BOARD_VENDOR, "ASUSTeK COMPUTER INC.") &&
2462 		    (dmi_match(DMI_BOARD_NAME, "PRIME B350M-A") ||
2463 		     dmi_match(DMI_BOARD_NAME, "PRIME Z370-A")))
2464 			return NVME_QUIRK_NO_APST;
2465 	}
2466 
2467 	return 0;
2468 }
2469 
2470 static void nvme_async_probe(void *data, async_cookie_t cookie)
2471 {
2472 	struct nvme_dev *dev = data;
2473 
2474 	nvme_reset_ctrl_sync(&dev->ctrl);
2475 	flush_work(&dev->ctrl.scan_work);
2476 	nvme_put_ctrl(&dev->ctrl);
2477 }
2478 
2479 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
2480 {
2481 	int node, result = -ENOMEM;
2482 	struct nvme_dev *dev;
2483 	unsigned long quirks = id->driver_data;
2484 	size_t alloc_size;
2485 
2486 	node = dev_to_node(&pdev->dev);
2487 	if (node == NUMA_NO_NODE)
2488 		set_dev_node(&pdev->dev, first_memory_node);
2489 
2490 	dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
2491 	if (!dev)
2492 		return -ENOMEM;
2493 
2494 	dev->queues = kcalloc_node(num_possible_cpus() + 1,
2495 			sizeof(struct nvme_queue), GFP_KERNEL, node);
2496 	if (!dev->queues)
2497 		goto free;
2498 
2499 	dev->dev = get_device(&pdev->dev);
2500 	pci_set_drvdata(pdev, dev);
2501 
2502 	result = nvme_dev_map(dev);
2503 	if (result)
2504 		goto put_pci;
2505 
2506 	INIT_WORK(&dev->ctrl.reset_work, nvme_reset_work);
2507 	INIT_WORK(&dev->remove_work, nvme_remove_dead_ctrl_work);
2508 	mutex_init(&dev->shutdown_lock);
2509 	init_completion(&dev->ioq_wait);
2510 
2511 	result = nvme_setup_prp_pools(dev);
2512 	if (result)
2513 		goto unmap;
2514 
2515 	quirks |= check_vendor_combination_bug(pdev);
2516 
2517 	/*
2518 	 * Double check that our mempool alloc size will cover the biggest
2519 	 * command we support.
2520 	 */
2521 	alloc_size = nvme_pci_iod_alloc_size(dev, NVME_MAX_KB_SZ,
2522 						NVME_MAX_SEGS, true);
2523 	WARN_ON_ONCE(alloc_size > PAGE_SIZE);
2524 
2525 	dev->iod_mempool = mempool_create_node(1, mempool_kmalloc,
2526 						mempool_kfree,
2527 						(void *) alloc_size,
2528 						GFP_KERNEL, node);
2529 	if (!dev->iod_mempool) {
2530 		result = -ENOMEM;
2531 		goto release_pools;
2532 	}
2533 
2534 	result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
2535 			quirks);
2536 	if (result)
2537 		goto release_mempool;
2538 
2539 	dev_info(dev->ctrl.device, "pci function %s\n", dev_name(&pdev->dev));
2540 
2541 	nvme_get_ctrl(&dev->ctrl);
2542 	async_schedule(nvme_async_probe, dev);
2543 
2544 	return 0;
2545 
2546  release_mempool:
2547 	mempool_destroy(dev->iod_mempool);
2548  release_pools:
2549 	nvme_release_prp_pools(dev);
2550  unmap:
2551 	nvme_dev_unmap(dev);
2552  put_pci:
2553 	put_device(dev->dev);
2554  free:
2555 	kfree(dev->queues);
2556 	kfree(dev);
2557 	return result;
2558 }
2559 
2560 static void nvme_reset_prepare(struct pci_dev *pdev)
2561 {
2562 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2563 	nvme_dev_disable(dev, false);
2564 }
2565 
2566 static void nvme_reset_done(struct pci_dev *pdev)
2567 {
2568 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2569 	nvme_reset_ctrl_sync(&dev->ctrl);
2570 }
2571 
2572 static void nvme_shutdown(struct pci_dev *pdev)
2573 {
2574 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2575 	nvme_dev_disable(dev, true);
2576 }
2577 
2578 /*
2579  * The driver's remove may be called on a device in a partially initialized
2580  * state. This function must not have any dependencies on the device state in
2581  * order to proceed.
2582  */
2583 static void nvme_remove(struct pci_dev *pdev)
2584 {
2585 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2586 
2587 	nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING);
2588 	pci_set_drvdata(pdev, NULL);
2589 
2590 	if (!pci_device_is_present(pdev)) {
2591 		nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DEAD);
2592 		nvme_dev_disable(dev, true);
2593 		nvme_dev_remove_admin(dev);
2594 	}
2595 
2596 	flush_work(&dev->ctrl.reset_work);
2597 	nvme_stop_ctrl(&dev->ctrl);
2598 	nvme_remove_namespaces(&dev->ctrl);
2599 	nvme_dev_disable(dev, true);
2600 	nvme_release_cmb(dev);
2601 	nvme_free_host_mem(dev);
2602 	nvme_dev_remove_admin(dev);
2603 	nvme_free_queues(dev, 0);
2604 	nvme_uninit_ctrl(&dev->ctrl);
2605 	nvme_release_prp_pools(dev);
2606 	nvme_dev_unmap(dev);
2607 	nvme_put_ctrl(&dev->ctrl);
2608 }
2609 
2610 #ifdef CONFIG_PM_SLEEP
2611 static int nvme_suspend(struct device *dev)
2612 {
2613 	struct pci_dev *pdev = to_pci_dev(dev);
2614 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2615 
2616 	nvme_dev_disable(ndev, true);
2617 	return 0;
2618 }
2619 
2620 static int nvme_resume(struct device *dev)
2621 {
2622 	struct pci_dev *pdev = to_pci_dev(dev);
2623 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2624 
2625 	nvme_reset_ctrl(&ndev->ctrl);
2626 	return 0;
2627 }
2628 #endif
2629 
2630 static SIMPLE_DEV_PM_OPS(nvme_dev_pm_ops, nvme_suspend, nvme_resume);
2631 
2632 static pci_ers_result_t nvme_error_detected(struct pci_dev *pdev,
2633 						pci_channel_state_t state)
2634 {
2635 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2636 
2637 	/*
2638 	 * A frozen channel requires a reset. When detected, this method will
2639 	 * shutdown the controller to quiesce. The controller will be restarted
2640 	 * after the slot reset through driver's slot_reset callback.
2641 	 */
2642 	switch (state) {
2643 	case pci_channel_io_normal:
2644 		return PCI_ERS_RESULT_CAN_RECOVER;
2645 	case pci_channel_io_frozen:
2646 		dev_warn(dev->ctrl.device,
2647 			"frozen state error detected, reset controller\n");
2648 		nvme_dev_disable(dev, false);
2649 		return PCI_ERS_RESULT_NEED_RESET;
2650 	case pci_channel_io_perm_failure:
2651 		dev_warn(dev->ctrl.device,
2652 			"failure state error detected, request disconnect\n");
2653 		return PCI_ERS_RESULT_DISCONNECT;
2654 	}
2655 	return PCI_ERS_RESULT_NEED_RESET;
2656 }
2657 
2658 static pci_ers_result_t nvme_slot_reset(struct pci_dev *pdev)
2659 {
2660 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2661 
2662 	dev_info(dev->ctrl.device, "restart after slot reset\n");
2663 	pci_restore_state(pdev);
2664 	nvme_reset_ctrl(&dev->ctrl);
2665 	return PCI_ERS_RESULT_RECOVERED;
2666 }
2667 
2668 static void nvme_error_resume(struct pci_dev *pdev)
2669 {
2670 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2671 
2672 	flush_work(&dev->ctrl.reset_work);
2673 }
2674 
2675 static const struct pci_error_handlers nvme_err_handler = {
2676 	.error_detected	= nvme_error_detected,
2677 	.slot_reset	= nvme_slot_reset,
2678 	.resume		= nvme_error_resume,
2679 	.reset_prepare	= nvme_reset_prepare,
2680 	.reset_done	= nvme_reset_done,
2681 };
2682 
2683 static const struct pci_device_id nvme_id_table[] = {
2684 	{ PCI_VDEVICE(INTEL, 0x0953),
2685 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2686 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2687 	{ PCI_VDEVICE(INTEL, 0x0a53),
2688 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2689 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2690 	{ PCI_VDEVICE(INTEL, 0x0a54),
2691 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2692 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2693 	{ PCI_VDEVICE(INTEL, 0x0a55),
2694 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2695 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2696 	{ PCI_VDEVICE(INTEL, 0xf1a5),	/* Intel 600P/P3100 */
2697 		.driver_data = NVME_QUIRK_NO_DEEPEST_PS |
2698 				NVME_QUIRK_MEDIUM_PRIO_SQ },
2699 	{ PCI_VDEVICE(INTEL, 0x5845),	/* Qemu emulated controller */
2700 		.driver_data = NVME_QUIRK_IDENTIFY_CNS, },
2701 	{ PCI_DEVICE(0x1bb1, 0x0100),   /* Seagate Nytro Flash Storage */
2702 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2703 	{ PCI_DEVICE(0x1c58, 0x0003),	/* HGST adapter */
2704 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2705 	{ PCI_DEVICE(0x1c58, 0x0023),	/* WDC SN200 adapter */
2706 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2707 	{ PCI_DEVICE(0x1c5f, 0x0540),	/* Memblaze Pblaze4 adapter */
2708 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2709 	{ PCI_DEVICE(0x144d, 0xa821),   /* Samsung PM1725 */
2710 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2711 	{ PCI_DEVICE(0x144d, 0xa822),   /* Samsung PM1725a */
2712 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2713 	{ PCI_DEVICE(0x1d1d, 0x1f1f),	/* LighNVM qemu device */
2714 		.driver_data = NVME_QUIRK_LIGHTNVM, },
2715 	{ PCI_DEVICE(0x1d1d, 0x2807),	/* CNEX WL */
2716 		.driver_data = NVME_QUIRK_LIGHTNVM, },
2717 	{ PCI_DEVICE(0x1d1d, 0x2601),	/* CNEX Granby */
2718 		.driver_data = NVME_QUIRK_LIGHTNVM, },
2719 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
2720 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
2721 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2003) },
2722 	{ 0, }
2723 };
2724 MODULE_DEVICE_TABLE(pci, nvme_id_table);
2725 
2726 static struct pci_driver nvme_driver = {
2727 	.name		= "nvme",
2728 	.id_table	= nvme_id_table,
2729 	.probe		= nvme_probe,
2730 	.remove		= nvme_remove,
2731 	.shutdown	= nvme_shutdown,
2732 	.driver		= {
2733 		.pm	= &nvme_dev_pm_ops,
2734 	},
2735 	.sriov_configure = pci_sriov_configure_simple,
2736 	.err_handler	= &nvme_err_handler,
2737 };
2738 
2739 static int __init nvme_init(void)
2740 {
2741 	return pci_register_driver(&nvme_driver);
2742 }
2743 
2744 static void __exit nvme_exit(void)
2745 {
2746 	pci_unregister_driver(&nvme_driver);
2747 	flush_workqueue(nvme_wq);
2748 	_nvme_check_size();
2749 }
2750 
2751 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
2752 MODULE_LICENSE("GPL");
2753 MODULE_VERSION("1.0");
2754 module_init(nvme_init);
2755 module_exit(nvme_exit);
2756