xref: /openbmc/linux/drivers/nvme/host/pci.c (revision dc6a81c3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * NVM Express device driver
4  * Copyright (c) 2011-2014, Intel Corporation.
5  */
6 
7 #include <linux/aer.h>
8 #include <linux/async.h>
9 #include <linux/blkdev.h>
10 #include <linux/blk-mq.h>
11 #include <linux/blk-mq-pci.h>
12 #include <linux/dmi.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/mm.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/once.h>
20 #include <linux/pci.h>
21 #include <linux/suspend.h>
22 #include <linux/t10-pi.h>
23 #include <linux/types.h>
24 #include <linux/io-64-nonatomic-lo-hi.h>
25 #include <linux/sed-opal.h>
26 #include <linux/pci-p2pdma.h>
27 
28 #include "trace.h"
29 #include "nvme.h"
30 
31 #define SQ_SIZE(q)	((q)->q_depth << (q)->sqes)
32 #define CQ_SIZE(q)	((q)->q_depth * sizeof(struct nvme_completion))
33 
34 #define SGES_PER_PAGE	(PAGE_SIZE / sizeof(struct nvme_sgl_desc))
35 
36 /*
37  * These can be higher, but we need to ensure that any command doesn't
38  * require an sg allocation that needs more than a page of data.
39  */
40 #define NVME_MAX_KB_SZ	4096
41 #define NVME_MAX_SEGS	127
42 
43 static int use_threaded_interrupts;
44 module_param(use_threaded_interrupts, int, 0);
45 
46 static bool use_cmb_sqes = true;
47 module_param(use_cmb_sqes, bool, 0444);
48 MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes");
49 
50 static unsigned int max_host_mem_size_mb = 128;
51 module_param(max_host_mem_size_mb, uint, 0444);
52 MODULE_PARM_DESC(max_host_mem_size_mb,
53 	"Maximum Host Memory Buffer (HMB) size per controller (in MiB)");
54 
55 static unsigned int sgl_threshold = SZ_32K;
56 module_param(sgl_threshold, uint, 0644);
57 MODULE_PARM_DESC(sgl_threshold,
58 		"Use SGLs when average request segment size is larger or equal to "
59 		"this size. Use 0 to disable SGLs.");
60 
61 static int io_queue_depth_set(const char *val, const struct kernel_param *kp);
62 static const struct kernel_param_ops io_queue_depth_ops = {
63 	.set = io_queue_depth_set,
64 	.get = param_get_int,
65 };
66 
67 static int io_queue_depth = 1024;
68 module_param_cb(io_queue_depth, &io_queue_depth_ops, &io_queue_depth, 0644);
69 MODULE_PARM_DESC(io_queue_depth, "set io queue depth, should >= 2");
70 
71 static unsigned int write_queues;
72 module_param(write_queues, uint, 0644);
73 MODULE_PARM_DESC(write_queues,
74 	"Number of queues to use for writes. If not set, reads and writes "
75 	"will share a queue set.");
76 
77 static unsigned int poll_queues;
78 module_param(poll_queues, uint, 0644);
79 MODULE_PARM_DESC(poll_queues, "Number of queues to use for polled IO.");
80 
81 struct nvme_dev;
82 struct nvme_queue;
83 
84 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
85 static bool __nvme_disable_io_queues(struct nvme_dev *dev, u8 opcode);
86 
87 /*
88  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
89  */
90 struct nvme_dev {
91 	struct nvme_queue *queues;
92 	struct blk_mq_tag_set tagset;
93 	struct blk_mq_tag_set admin_tagset;
94 	u32 __iomem *dbs;
95 	struct device *dev;
96 	struct dma_pool *prp_page_pool;
97 	struct dma_pool *prp_small_pool;
98 	unsigned online_queues;
99 	unsigned max_qid;
100 	unsigned io_queues[HCTX_MAX_TYPES];
101 	unsigned int num_vecs;
102 	int q_depth;
103 	int io_sqes;
104 	u32 db_stride;
105 	void __iomem *bar;
106 	unsigned long bar_mapped_size;
107 	struct work_struct remove_work;
108 	struct mutex shutdown_lock;
109 	bool subsystem;
110 	u64 cmb_size;
111 	bool cmb_use_sqes;
112 	u32 cmbsz;
113 	u32 cmbloc;
114 	struct nvme_ctrl ctrl;
115 	u32 last_ps;
116 
117 	mempool_t *iod_mempool;
118 
119 	/* shadow doorbell buffer support: */
120 	u32 *dbbuf_dbs;
121 	dma_addr_t dbbuf_dbs_dma_addr;
122 	u32 *dbbuf_eis;
123 	dma_addr_t dbbuf_eis_dma_addr;
124 
125 	/* host memory buffer support: */
126 	u64 host_mem_size;
127 	u32 nr_host_mem_descs;
128 	dma_addr_t host_mem_descs_dma;
129 	struct nvme_host_mem_buf_desc *host_mem_descs;
130 	void **host_mem_desc_bufs;
131 };
132 
133 static int io_queue_depth_set(const char *val, const struct kernel_param *kp)
134 {
135 	int n = 0, ret;
136 
137 	ret = kstrtoint(val, 10, &n);
138 	if (ret != 0 || n < 2)
139 		return -EINVAL;
140 
141 	return param_set_int(val, kp);
142 }
143 
144 static inline unsigned int sq_idx(unsigned int qid, u32 stride)
145 {
146 	return qid * 2 * stride;
147 }
148 
149 static inline unsigned int cq_idx(unsigned int qid, u32 stride)
150 {
151 	return (qid * 2 + 1) * stride;
152 }
153 
154 static inline struct nvme_dev *to_nvme_dev(struct nvme_ctrl *ctrl)
155 {
156 	return container_of(ctrl, struct nvme_dev, ctrl);
157 }
158 
159 /*
160  * An NVM Express queue.  Each device has at least two (one for admin
161  * commands and one for I/O commands).
162  */
163 struct nvme_queue {
164 	struct nvme_dev *dev;
165 	spinlock_t sq_lock;
166 	void *sq_cmds;
167 	 /* only used for poll queues: */
168 	spinlock_t cq_poll_lock ____cacheline_aligned_in_smp;
169 	volatile struct nvme_completion *cqes;
170 	dma_addr_t sq_dma_addr;
171 	dma_addr_t cq_dma_addr;
172 	u32 __iomem *q_db;
173 	u16 q_depth;
174 	u16 cq_vector;
175 	u16 sq_tail;
176 	u16 last_sq_tail;
177 	u16 cq_head;
178 	u16 qid;
179 	u8 cq_phase;
180 	u8 sqes;
181 	unsigned long flags;
182 #define NVMEQ_ENABLED		0
183 #define NVMEQ_SQ_CMB		1
184 #define NVMEQ_DELETE_ERROR	2
185 #define NVMEQ_POLLED		3
186 	u32 *dbbuf_sq_db;
187 	u32 *dbbuf_cq_db;
188 	u32 *dbbuf_sq_ei;
189 	u32 *dbbuf_cq_ei;
190 	struct completion delete_done;
191 };
192 
193 /*
194  * The nvme_iod describes the data in an I/O.
195  *
196  * The sg pointer contains the list of PRP/SGL chunk allocations in addition
197  * to the actual struct scatterlist.
198  */
199 struct nvme_iod {
200 	struct nvme_request req;
201 	struct nvme_queue *nvmeq;
202 	bool use_sgl;
203 	int aborted;
204 	int npages;		/* In the PRP list. 0 means small pool in use */
205 	int nents;		/* Used in scatterlist */
206 	dma_addr_t first_dma;
207 	unsigned int dma_len;	/* length of single DMA segment mapping */
208 	dma_addr_t meta_dma;
209 	struct scatterlist *sg;
210 };
211 
212 static unsigned int max_io_queues(void)
213 {
214 	return num_possible_cpus() + write_queues + poll_queues;
215 }
216 
217 static unsigned int max_queue_count(void)
218 {
219 	/* IO queues + admin queue */
220 	return 1 + max_io_queues();
221 }
222 
223 static inline unsigned int nvme_dbbuf_size(u32 stride)
224 {
225 	return (max_queue_count() * 8 * stride);
226 }
227 
228 static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
229 {
230 	unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
231 
232 	if (dev->dbbuf_dbs)
233 		return 0;
234 
235 	dev->dbbuf_dbs = dma_alloc_coherent(dev->dev, mem_size,
236 					    &dev->dbbuf_dbs_dma_addr,
237 					    GFP_KERNEL);
238 	if (!dev->dbbuf_dbs)
239 		return -ENOMEM;
240 	dev->dbbuf_eis = dma_alloc_coherent(dev->dev, mem_size,
241 					    &dev->dbbuf_eis_dma_addr,
242 					    GFP_KERNEL);
243 	if (!dev->dbbuf_eis) {
244 		dma_free_coherent(dev->dev, mem_size,
245 				  dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
246 		dev->dbbuf_dbs = NULL;
247 		return -ENOMEM;
248 	}
249 
250 	return 0;
251 }
252 
253 static void nvme_dbbuf_dma_free(struct nvme_dev *dev)
254 {
255 	unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
256 
257 	if (dev->dbbuf_dbs) {
258 		dma_free_coherent(dev->dev, mem_size,
259 				  dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
260 		dev->dbbuf_dbs = NULL;
261 	}
262 	if (dev->dbbuf_eis) {
263 		dma_free_coherent(dev->dev, mem_size,
264 				  dev->dbbuf_eis, dev->dbbuf_eis_dma_addr);
265 		dev->dbbuf_eis = NULL;
266 	}
267 }
268 
269 static void nvme_dbbuf_init(struct nvme_dev *dev,
270 			    struct nvme_queue *nvmeq, int qid)
271 {
272 	if (!dev->dbbuf_dbs || !qid)
273 		return;
274 
275 	nvmeq->dbbuf_sq_db = &dev->dbbuf_dbs[sq_idx(qid, dev->db_stride)];
276 	nvmeq->dbbuf_cq_db = &dev->dbbuf_dbs[cq_idx(qid, dev->db_stride)];
277 	nvmeq->dbbuf_sq_ei = &dev->dbbuf_eis[sq_idx(qid, dev->db_stride)];
278 	nvmeq->dbbuf_cq_ei = &dev->dbbuf_eis[cq_idx(qid, dev->db_stride)];
279 }
280 
281 static void nvme_dbbuf_set(struct nvme_dev *dev)
282 {
283 	struct nvme_command c;
284 
285 	if (!dev->dbbuf_dbs)
286 		return;
287 
288 	memset(&c, 0, sizeof(c));
289 	c.dbbuf.opcode = nvme_admin_dbbuf;
290 	c.dbbuf.prp1 = cpu_to_le64(dev->dbbuf_dbs_dma_addr);
291 	c.dbbuf.prp2 = cpu_to_le64(dev->dbbuf_eis_dma_addr);
292 
293 	if (nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0)) {
294 		dev_warn(dev->ctrl.device, "unable to set dbbuf\n");
295 		/* Free memory and continue on */
296 		nvme_dbbuf_dma_free(dev);
297 	}
298 }
299 
300 static inline int nvme_dbbuf_need_event(u16 event_idx, u16 new_idx, u16 old)
301 {
302 	return (u16)(new_idx - event_idx - 1) < (u16)(new_idx - old);
303 }
304 
305 /* Update dbbuf and return true if an MMIO is required */
306 static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db,
307 					      volatile u32 *dbbuf_ei)
308 {
309 	if (dbbuf_db) {
310 		u16 old_value;
311 
312 		/*
313 		 * Ensure that the queue is written before updating
314 		 * the doorbell in memory
315 		 */
316 		wmb();
317 
318 		old_value = *dbbuf_db;
319 		*dbbuf_db = value;
320 
321 		/*
322 		 * Ensure that the doorbell is updated before reading the event
323 		 * index from memory.  The controller needs to provide similar
324 		 * ordering to ensure the envent index is updated before reading
325 		 * the doorbell.
326 		 */
327 		mb();
328 
329 		if (!nvme_dbbuf_need_event(*dbbuf_ei, value, old_value))
330 			return false;
331 	}
332 
333 	return true;
334 }
335 
336 /*
337  * Will slightly overestimate the number of pages needed.  This is OK
338  * as it only leads to a small amount of wasted memory for the lifetime of
339  * the I/O.
340  */
341 static int nvme_npages(unsigned size, struct nvme_dev *dev)
342 {
343 	unsigned nprps = DIV_ROUND_UP(size + dev->ctrl.page_size,
344 				      dev->ctrl.page_size);
345 	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
346 }
347 
348 /*
349  * Calculates the number of pages needed for the SGL segments. For example a 4k
350  * page can accommodate 256 SGL descriptors.
351  */
352 static int nvme_pci_npages_sgl(unsigned int num_seg)
353 {
354 	return DIV_ROUND_UP(num_seg * sizeof(struct nvme_sgl_desc), PAGE_SIZE);
355 }
356 
357 static unsigned int nvme_pci_iod_alloc_size(struct nvme_dev *dev,
358 		unsigned int size, unsigned int nseg, bool use_sgl)
359 {
360 	size_t alloc_size;
361 
362 	if (use_sgl)
363 		alloc_size = sizeof(__le64 *) * nvme_pci_npages_sgl(nseg);
364 	else
365 		alloc_size = sizeof(__le64 *) * nvme_npages(size, dev);
366 
367 	return alloc_size + sizeof(struct scatterlist) * nseg;
368 }
369 
370 static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
371 				unsigned int hctx_idx)
372 {
373 	struct nvme_dev *dev = data;
374 	struct nvme_queue *nvmeq = &dev->queues[0];
375 
376 	WARN_ON(hctx_idx != 0);
377 	WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);
378 
379 	hctx->driver_data = nvmeq;
380 	return 0;
381 }
382 
383 static int nvme_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[hctx_idx + 1];
388 
389 	WARN_ON(dev->tagset.tags[hctx_idx] != hctx->tags);
390 	hctx->driver_data = nvmeq;
391 	return 0;
392 }
393 
394 static int nvme_init_request(struct blk_mq_tag_set *set, struct request *req,
395 		unsigned int hctx_idx, unsigned int numa_node)
396 {
397 	struct nvme_dev *dev = set->driver_data;
398 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
399 	int queue_idx = (set == &dev->tagset) ? hctx_idx + 1 : 0;
400 	struct nvme_queue *nvmeq = &dev->queues[queue_idx];
401 
402 	BUG_ON(!nvmeq);
403 	iod->nvmeq = nvmeq;
404 
405 	nvme_req(req)->ctrl = &dev->ctrl;
406 	return 0;
407 }
408 
409 static int queue_irq_offset(struct nvme_dev *dev)
410 {
411 	/* if we have more than 1 vec, admin queue offsets us by 1 */
412 	if (dev->num_vecs > 1)
413 		return 1;
414 
415 	return 0;
416 }
417 
418 static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
419 {
420 	struct nvme_dev *dev = set->driver_data;
421 	int i, qoff, offset;
422 
423 	offset = queue_irq_offset(dev);
424 	for (i = 0, qoff = 0; i < set->nr_maps; i++) {
425 		struct blk_mq_queue_map *map = &set->map[i];
426 
427 		map->nr_queues = dev->io_queues[i];
428 		if (!map->nr_queues) {
429 			BUG_ON(i == HCTX_TYPE_DEFAULT);
430 			continue;
431 		}
432 
433 		/*
434 		 * The poll queue(s) doesn't have an IRQ (and hence IRQ
435 		 * affinity), so use the regular blk-mq cpu mapping
436 		 */
437 		map->queue_offset = qoff;
438 		if (i != HCTX_TYPE_POLL && offset)
439 			blk_mq_pci_map_queues(map, to_pci_dev(dev->dev), offset);
440 		else
441 			blk_mq_map_queues(map);
442 		qoff += map->nr_queues;
443 		offset += map->nr_queues;
444 	}
445 
446 	return 0;
447 }
448 
449 /*
450  * Write sq tail if we are asked to, or if the next command would wrap.
451  */
452 static inline void nvme_write_sq_db(struct nvme_queue *nvmeq, bool write_sq)
453 {
454 	if (!write_sq) {
455 		u16 next_tail = nvmeq->sq_tail + 1;
456 
457 		if (next_tail == nvmeq->q_depth)
458 			next_tail = 0;
459 		if (next_tail != nvmeq->last_sq_tail)
460 			return;
461 	}
462 
463 	if (nvme_dbbuf_update_and_check_event(nvmeq->sq_tail,
464 			nvmeq->dbbuf_sq_db, nvmeq->dbbuf_sq_ei))
465 		writel(nvmeq->sq_tail, nvmeq->q_db);
466 	nvmeq->last_sq_tail = nvmeq->sq_tail;
467 }
468 
469 /**
470  * nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
471  * @nvmeq: The queue to use
472  * @cmd: The command to send
473  * @write_sq: whether to write to the SQ doorbell
474  */
475 static void nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd,
476 			    bool write_sq)
477 {
478 	spin_lock(&nvmeq->sq_lock);
479 	memcpy(nvmeq->sq_cmds + (nvmeq->sq_tail << nvmeq->sqes),
480 	       cmd, sizeof(*cmd));
481 	if (++nvmeq->sq_tail == nvmeq->q_depth)
482 		nvmeq->sq_tail = 0;
483 	nvme_write_sq_db(nvmeq, write_sq);
484 	spin_unlock(&nvmeq->sq_lock);
485 }
486 
487 static void nvme_commit_rqs(struct blk_mq_hw_ctx *hctx)
488 {
489 	struct nvme_queue *nvmeq = hctx->driver_data;
490 
491 	spin_lock(&nvmeq->sq_lock);
492 	if (nvmeq->sq_tail != nvmeq->last_sq_tail)
493 		nvme_write_sq_db(nvmeq, true);
494 	spin_unlock(&nvmeq->sq_lock);
495 }
496 
497 static void **nvme_pci_iod_list(struct request *req)
498 {
499 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
500 	return (void **)(iod->sg + blk_rq_nr_phys_segments(req));
501 }
502 
503 static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req)
504 {
505 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
506 	int nseg = blk_rq_nr_phys_segments(req);
507 	unsigned int avg_seg_size;
508 
509 	if (nseg == 0)
510 		return false;
511 
512 	avg_seg_size = DIV_ROUND_UP(blk_rq_payload_bytes(req), nseg);
513 
514 	if (!(dev->ctrl.sgls & ((1 << 0) | (1 << 1))))
515 		return false;
516 	if (!iod->nvmeq->qid)
517 		return false;
518 	if (!sgl_threshold || avg_seg_size < sgl_threshold)
519 		return false;
520 	return true;
521 }
522 
523 static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
524 {
525 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
526 	const int last_prp = dev->ctrl.page_size / sizeof(__le64) - 1;
527 	dma_addr_t dma_addr = iod->first_dma, next_dma_addr;
528 	int i;
529 
530 	if (iod->dma_len) {
531 		dma_unmap_page(dev->dev, dma_addr, iod->dma_len,
532 			       rq_dma_dir(req));
533 		return;
534 	}
535 
536 	WARN_ON_ONCE(!iod->nents);
537 
538 	if (is_pci_p2pdma_page(sg_page(iod->sg)))
539 		pci_p2pdma_unmap_sg(dev->dev, iod->sg, iod->nents,
540 				    rq_dma_dir(req));
541 	else
542 		dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req));
543 
544 
545 	if (iod->npages == 0)
546 		dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0],
547 			dma_addr);
548 
549 	for (i = 0; i < iod->npages; i++) {
550 		void *addr = nvme_pci_iod_list(req)[i];
551 
552 		if (iod->use_sgl) {
553 			struct nvme_sgl_desc *sg_list = addr;
554 
555 			next_dma_addr =
556 			    le64_to_cpu((sg_list[SGES_PER_PAGE - 1]).addr);
557 		} else {
558 			__le64 *prp_list = addr;
559 
560 			next_dma_addr = le64_to_cpu(prp_list[last_prp]);
561 		}
562 
563 		dma_pool_free(dev->prp_page_pool, addr, dma_addr);
564 		dma_addr = next_dma_addr;
565 	}
566 
567 	mempool_free(iod->sg, dev->iod_mempool);
568 }
569 
570 static void nvme_print_sgl(struct scatterlist *sgl, int nents)
571 {
572 	int i;
573 	struct scatterlist *sg;
574 
575 	for_each_sg(sgl, sg, nents, i) {
576 		dma_addr_t phys = sg_phys(sg);
577 		pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d "
578 			"dma_address:%pad dma_length:%d\n",
579 			i, &phys, sg->offset, sg->length, &sg_dma_address(sg),
580 			sg_dma_len(sg));
581 	}
582 }
583 
584 static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev,
585 		struct request *req, struct nvme_rw_command *cmnd)
586 {
587 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
588 	struct dma_pool *pool;
589 	int length = blk_rq_payload_bytes(req);
590 	struct scatterlist *sg = iod->sg;
591 	int dma_len = sg_dma_len(sg);
592 	u64 dma_addr = sg_dma_address(sg);
593 	u32 page_size = dev->ctrl.page_size;
594 	int offset = dma_addr & (page_size - 1);
595 	__le64 *prp_list;
596 	void **list = nvme_pci_iod_list(req);
597 	dma_addr_t prp_dma;
598 	int nprps, i;
599 
600 	length -= (page_size - offset);
601 	if (length <= 0) {
602 		iod->first_dma = 0;
603 		goto done;
604 	}
605 
606 	dma_len -= (page_size - offset);
607 	if (dma_len) {
608 		dma_addr += (page_size - offset);
609 	} else {
610 		sg = sg_next(sg);
611 		dma_addr = sg_dma_address(sg);
612 		dma_len = sg_dma_len(sg);
613 	}
614 
615 	if (length <= page_size) {
616 		iod->first_dma = dma_addr;
617 		goto done;
618 	}
619 
620 	nprps = DIV_ROUND_UP(length, page_size);
621 	if (nprps <= (256 / 8)) {
622 		pool = dev->prp_small_pool;
623 		iod->npages = 0;
624 	} else {
625 		pool = dev->prp_page_pool;
626 		iod->npages = 1;
627 	}
628 
629 	prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
630 	if (!prp_list) {
631 		iod->first_dma = dma_addr;
632 		iod->npages = -1;
633 		return BLK_STS_RESOURCE;
634 	}
635 	list[0] = prp_list;
636 	iod->first_dma = prp_dma;
637 	i = 0;
638 	for (;;) {
639 		if (i == page_size >> 3) {
640 			__le64 *old_prp_list = prp_list;
641 			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
642 			if (!prp_list)
643 				return BLK_STS_RESOURCE;
644 			list[iod->npages++] = prp_list;
645 			prp_list[0] = old_prp_list[i - 1];
646 			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
647 			i = 1;
648 		}
649 		prp_list[i++] = cpu_to_le64(dma_addr);
650 		dma_len -= page_size;
651 		dma_addr += page_size;
652 		length -= page_size;
653 		if (length <= 0)
654 			break;
655 		if (dma_len > 0)
656 			continue;
657 		if (unlikely(dma_len < 0))
658 			goto bad_sgl;
659 		sg = sg_next(sg);
660 		dma_addr = sg_dma_address(sg);
661 		dma_len = sg_dma_len(sg);
662 	}
663 
664 done:
665 	cmnd->dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
666 	cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma);
667 
668 	return BLK_STS_OK;
669 
670  bad_sgl:
671 	WARN(DO_ONCE(nvme_print_sgl, iod->sg, iod->nents),
672 			"Invalid SGL for payload:%d nents:%d\n",
673 			blk_rq_payload_bytes(req), iod->nents);
674 	return BLK_STS_IOERR;
675 }
676 
677 static void nvme_pci_sgl_set_data(struct nvme_sgl_desc *sge,
678 		struct scatterlist *sg)
679 {
680 	sge->addr = cpu_to_le64(sg_dma_address(sg));
681 	sge->length = cpu_to_le32(sg_dma_len(sg));
682 	sge->type = NVME_SGL_FMT_DATA_DESC << 4;
683 }
684 
685 static void nvme_pci_sgl_set_seg(struct nvme_sgl_desc *sge,
686 		dma_addr_t dma_addr, int entries)
687 {
688 	sge->addr = cpu_to_le64(dma_addr);
689 	if (entries < SGES_PER_PAGE) {
690 		sge->length = cpu_to_le32(entries * sizeof(*sge));
691 		sge->type = NVME_SGL_FMT_LAST_SEG_DESC << 4;
692 	} else {
693 		sge->length = cpu_to_le32(PAGE_SIZE);
694 		sge->type = NVME_SGL_FMT_SEG_DESC << 4;
695 	}
696 }
697 
698 static blk_status_t nvme_pci_setup_sgls(struct nvme_dev *dev,
699 		struct request *req, struct nvme_rw_command *cmd, int entries)
700 {
701 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
702 	struct dma_pool *pool;
703 	struct nvme_sgl_desc *sg_list;
704 	struct scatterlist *sg = iod->sg;
705 	dma_addr_t sgl_dma;
706 	int i = 0;
707 
708 	/* setting the transfer type as SGL */
709 	cmd->flags = NVME_CMD_SGL_METABUF;
710 
711 	if (entries == 1) {
712 		nvme_pci_sgl_set_data(&cmd->dptr.sgl, sg);
713 		return BLK_STS_OK;
714 	}
715 
716 	if (entries <= (256 / sizeof(struct nvme_sgl_desc))) {
717 		pool = dev->prp_small_pool;
718 		iod->npages = 0;
719 	} else {
720 		pool = dev->prp_page_pool;
721 		iod->npages = 1;
722 	}
723 
724 	sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
725 	if (!sg_list) {
726 		iod->npages = -1;
727 		return BLK_STS_RESOURCE;
728 	}
729 
730 	nvme_pci_iod_list(req)[0] = sg_list;
731 	iod->first_dma = sgl_dma;
732 
733 	nvme_pci_sgl_set_seg(&cmd->dptr.sgl, sgl_dma, entries);
734 
735 	do {
736 		if (i == SGES_PER_PAGE) {
737 			struct nvme_sgl_desc *old_sg_desc = sg_list;
738 			struct nvme_sgl_desc *link = &old_sg_desc[i - 1];
739 
740 			sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
741 			if (!sg_list)
742 				return BLK_STS_RESOURCE;
743 
744 			i = 0;
745 			nvme_pci_iod_list(req)[iod->npages++] = sg_list;
746 			sg_list[i++] = *link;
747 			nvme_pci_sgl_set_seg(link, sgl_dma, entries);
748 		}
749 
750 		nvme_pci_sgl_set_data(&sg_list[i++], sg);
751 		sg = sg_next(sg);
752 	} while (--entries > 0);
753 
754 	return BLK_STS_OK;
755 }
756 
757 static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev,
758 		struct request *req, struct nvme_rw_command *cmnd,
759 		struct bio_vec *bv)
760 {
761 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
762 	unsigned int offset = bv->bv_offset & (dev->ctrl.page_size - 1);
763 	unsigned int first_prp_len = dev->ctrl.page_size - offset;
764 
765 	iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);
766 	if (dma_mapping_error(dev->dev, iod->first_dma))
767 		return BLK_STS_RESOURCE;
768 	iod->dma_len = bv->bv_len;
769 
770 	cmnd->dptr.prp1 = cpu_to_le64(iod->first_dma);
771 	if (bv->bv_len > first_prp_len)
772 		cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma + first_prp_len);
773 	return 0;
774 }
775 
776 static blk_status_t nvme_setup_sgl_simple(struct nvme_dev *dev,
777 		struct request *req, struct nvme_rw_command *cmnd,
778 		struct bio_vec *bv)
779 {
780 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
781 
782 	iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);
783 	if (dma_mapping_error(dev->dev, iod->first_dma))
784 		return BLK_STS_RESOURCE;
785 	iod->dma_len = bv->bv_len;
786 
787 	cmnd->flags = NVME_CMD_SGL_METABUF;
788 	cmnd->dptr.sgl.addr = cpu_to_le64(iod->first_dma);
789 	cmnd->dptr.sgl.length = cpu_to_le32(iod->dma_len);
790 	cmnd->dptr.sgl.type = NVME_SGL_FMT_DATA_DESC << 4;
791 	return 0;
792 }
793 
794 static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
795 		struct nvme_command *cmnd)
796 {
797 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
798 	blk_status_t ret = BLK_STS_RESOURCE;
799 	int nr_mapped;
800 
801 	if (blk_rq_nr_phys_segments(req) == 1) {
802 		struct bio_vec bv = req_bvec(req);
803 
804 		if (!is_pci_p2pdma_page(bv.bv_page)) {
805 			if (bv.bv_offset + bv.bv_len <= dev->ctrl.page_size * 2)
806 				return nvme_setup_prp_simple(dev, req,
807 							     &cmnd->rw, &bv);
808 
809 			if (iod->nvmeq->qid &&
810 			    dev->ctrl.sgls & ((1 << 0) | (1 << 1)))
811 				return nvme_setup_sgl_simple(dev, req,
812 							     &cmnd->rw, &bv);
813 		}
814 	}
815 
816 	iod->dma_len = 0;
817 	iod->sg = mempool_alloc(dev->iod_mempool, GFP_ATOMIC);
818 	if (!iod->sg)
819 		return BLK_STS_RESOURCE;
820 	sg_init_table(iod->sg, blk_rq_nr_phys_segments(req));
821 	iod->nents = blk_rq_map_sg(req->q, req, iod->sg);
822 	if (!iod->nents)
823 		goto out;
824 
825 	if (is_pci_p2pdma_page(sg_page(iod->sg)))
826 		nr_mapped = pci_p2pdma_map_sg_attrs(dev->dev, iod->sg,
827 				iod->nents, rq_dma_dir(req), DMA_ATTR_NO_WARN);
828 	else
829 		nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents,
830 					     rq_dma_dir(req), DMA_ATTR_NO_WARN);
831 	if (!nr_mapped)
832 		goto out;
833 
834 	iod->use_sgl = nvme_pci_use_sgls(dev, req);
835 	if (iod->use_sgl)
836 		ret = nvme_pci_setup_sgls(dev, req, &cmnd->rw, nr_mapped);
837 	else
838 		ret = nvme_pci_setup_prps(dev, req, &cmnd->rw);
839 out:
840 	if (ret != BLK_STS_OK)
841 		nvme_unmap_data(dev, req);
842 	return ret;
843 }
844 
845 static blk_status_t nvme_map_metadata(struct nvme_dev *dev, struct request *req,
846 		struct nvme_command *cmnd)
847 {
848 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
849 
850 	iod->meta_dma = dma_map_bvec(dev->dev, rq_integrity_vec(req),
851 			rq_dma_dir(req), 0);
852 	if (dma_mapping_error(dev->dev, iod->meta_dma))
853 		return BLK_STS_IOERR;
854 	cmnd->rw.metadata = cpu_to_le64(iod->meta_dma);
855 	return 0;
856 }
857 
858 /*
859  * NOTE: ns is NULL when called on the admin queue.
860  */
861 static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
862 			 const struct blk_mq_queue_data *bd)
863 {
864 	struct nvme_ns *ns = hctx->queue->queuedata;
865 	struct nvme_queue *nvmeq = hctx->driver_data;
866 	struct nvme_dev *dev = nvmeq->dev;
867 	struct request *req = bd->rq;
868 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
869 	struct nvme_command cmnd;
870 	blk_status_t ret;
871 
872 	iod->aborted = 0;
873 	iod->npages = -1;
874 	iod->nents = 0;
875 
876 	/*
877 	 * We should not need to do this, but we're still using this to
878 	 * ensure we can drain requests on a dying queue.
879 	 */
880 	if (unlikely(!test_bit(NVMEQ_ENABLED, &nvmeq->flags)))
881 		return BLK_STS_IOERR;
882 
883 	ret = nvme_setup_cmd(ns, req, &cmnd);
884 	if (ret)
885 		return ret;
886 
887 	if (blk_rq_nr_phys_segments(req)) {
888 		ret = nvme_map_data(dev, req, &cmnd);
889 		if (ret)
890 			goto out_free_cmd;
891 	}
892 
893 	if (blk_integrity_rq(req)) {
894 		ret = nvme_map_metadata(dev, req, &cmnd);
895 		if (ret)
896 			goto out_unmap_data;
897 	}
898 
899 	blk_mq_start_request(req);
900 	nvme_submit_cmd(nvmeq, &cmnd, bd->last);
901 	return BLK_STS_OK;
902 out_unmap_data:
903 	nvme_unmap_data(dev, req);
904 out_free_cmd:
905 	nvme_cleanup_cmd(req);
906 	return ret;
907 }
908 
909 static void nvme_pci_complete_rq(struct request *req)
910 {
911 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
912 	struct nvme_dev *dev = iod->nvmeq->dev;
913 
914 	if (blk_integrity_rq(req))
915 		dma_unmap_page(dev->dev, iod->meta_dma,
916 			       rq_integrity_vec(req)->bv_len, rq_data_dir(req));
917 	if (blk_rq_nr_phys_segments(req))
918 		nvme_unmap_data(dev, req);
919 	nvme_complete_rq(req);
920 }
921 
922 /* We read the CQE phase first to check if the rest of the entry is valid */
923 static inline bool nvme_cqe_pending(struct nvme_queue *nvmeq)
924 {
925 	return (le16_to_cpu(nvmeq->cqes[nvmeq->cq_head].status) & 1) ==
926 			nvmeq->cq_phase;
927 }
928 
929 static inline void nvme_ring_cq_doorbell(struct nvme_queue *nvmeq)
930 {
931 	u16 head = nvmeq->cq_head;
932 
933 	if (nvme_dbbuf_update_and_check_event(head, nvmeq->dbbuf_cq_db,
934 					      nvmeq->dbbuf_cq_ei))
935 		writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
936 }
937 
938 static inline struct blk_mq_tags *nvme_queue_tagset(struct nvme_queue *nvmeq)
939 {
940 	if (!nvmeq->qid)
941 		return nvmeq->dev->admin_tagset.tags[0];
942 	return nvmeq->dev->tagset.tags[nvmeq->qid - 1];
943 }
944 
945 static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx)
946 {
947 	volatile struct nvme_completion *cqe = &nvmeq->cqes[idx];
948 	struct request *req;
949 
950 	if (unlikely(cqe->command_id >= nvmeq->q_depth)) {
951 		dev_warn(nvmeq->dev->ctrl.device,
952 			"invalid id %d completed on queue %d\n",
953 			cqe->command_id, le16_to_cpu(cqe->sq_id));
954 		return;
955 	}
956 
957 	/*
958 	 * AEN requests are special as they don't time out and can
959 	 * survive any kind of queue freeze and often don't respond to
960 	 * aborts.  We don't even bother to allocate a struct request
961 	 * for them but rather special case them here.
962 	 */
963 	if (unlikely(nvme_is_aen_req(nvmeq->qid, cqe->command_id))) {
964 		nvme_complete_async_event(&nvmeq->dev->ctrl,
965 				cqe->status, &cqe->result);
966 		return;
967 	}
968 
969 	req = blk_mq_tag_to_rq(nvme_queue_tagset(nvmeq), cqe->command_id);
970 	trace_nvme_sq(req, cqe->sq_head, nvmeq->sq_tail);
971 	nvme_end_request(req, cqe->status, cqe->result);
972 }
973 
974 static void nvme_complete_cqes(struct nvme_queue *nvmeq, u16 start, u16 end)
975 {
976 	while (start != end) {
977 		nvme_handle_cqe(nvmeq, start);
978 		if (++start == nvmeq->q_depth)
979 			start = 0;
980 	}
981 }
982 
983 static inline void nvme_update_cq_head(struct nvme_queue *nvmeq)
984 {
985 	if (nvmeq->cq_head == nvmeq->q_depth - 1) {
986 		nvmeq->cq_head = 0;
987 		nvmeq->cq_phase = !nvmeq->cq_phase;
988 	} else {
989 		nvmeq->cq_head++;
990 	}
991 }
992 
993 static inline int nvme_process_cq(struct nvme_queue *nvmeq, u16 *start,
994 				  u16 *end, unsigned int tag)
995 {
996 	int found = 0;
997 
998 	*start = nvmeq->cq_head;
999 	while (nvme_cqe_pending(nvmeq)) {
1000 		if (tag == -1U || nvmeq->cqes[nvmeq->cq_head].command_id == tag)
1001 			found++;
1002 		nvme_update_cq_head(nvmeq);
1003 	}
1004 	*end = nvmeq->cq_head;
1005 
1006 	if (*start != *end)
1007 		nvme_ring_cq_doorbell(nvmeq);
1008 	return found;
1009 }
1010 
1011 static irqreturn_t nvme_irq(int irq, void *data)
1012 {
1013 	struct nvme_queue *nvmeq = data;
1014 	irqreturn_t ret = IRQ_NONE;
1015 	u16 start, end;
1016 
1017 	/*
1018 	 * The rmb/wmb pair ensures we see all updates from a previous run of
1019 	 * the irq handler, even if that was on another CPU.
1020 	 */
1021 	rmb();
1022 	nvme_process_cq(nvmeq, &start, &end, -1);
1023 	wmb();
1024 
1025 	if (start != end) {
1026 		nvme_complete_cqes(nvmeq, start, end);
1027 		return IRQ_HANDLED;
1028 	}
1029 
1030 	return ret;
1031 }
1032 
1033 static irqreturn_t nvme_irq_check(int irq, void *data)
1034 {
1035 	struct nvme_queue *nvmeq = data;
1036 	if (nvme_cqe_pending(nvmeq))
1037 		return IRQ_WAKE_THREAD;
1038 	return IRQ_NONE;
1039 }
1040 
1041 /*
1042  * Poll for completions any queue, including those not dedicated to polling.
1043  * Can be called from any context.
1044  */
1045 static int nvme_poll_irqdisable(struct nvme_queue *nvmeq, unsigned int tag)
1046 {
1047 	struct pci_dev *pdev = to_pci_dev(nvmeq->dev->dev);
1048 	u16 start, end;
1049 	int found;
1050 
1051 	/*
1052 	 * For a poll queue we need to protect against the polling thread
1053 	 * using the CQ lock.  For normal interrupt driven threads we have
1054 	 * to disable the interrupt to avoid racing with it.
1055 	 */
1056 	if (test_bit(NVMEQ_POLLED, &nvmeq->flags)) {
1057 		spin_lock(&nvmeq->cq_poll_lock);
1058 		found = nvme_process_cq(nvmeq, &start, &end, tag);
1059 		spin_unlock(&nvmeq->cq_poll_lock);
1060 	} else {
1061 		disable_irq(pci_irq_vector(pdev, nvmeq->cq_vector));
1062 		found = nvme_process_cq(nvmeq, &start, &end, tag);
1063 		enable_irq(pci_irq_vector(pdev, nvmeq->cq_vector));
1064 	}
1065 
1066 	nvme_complete_cqes(nvmeq, start, end);
1067 	return found;
1068 }
1069 
1070 static int nvme_poll(struct blk_mq_hw_ctx *hctx)
1071 {
1072 	struct nvme_queue *nvmeq = hctx->driver_data;
1073 	u16 start, end;
1074 	bool found;
1075 
1076 	if (!nvme_cqe_pending(nvmeq))
1077 		return 0;
1078 
1079 	spin_lock(&nvmeq->cq_poll_lock);
1080 	found = nvme_process_cq(nvmeq, &start, &end, -1);
1081 	spin_unlock(&nvmeq->cq_poll_lock);
1082 
1083 	nvme_complete_cqes(nvmeq, start, end);
1084 	return found;
1085 }
1086 
1087 static void nvme_pci_submit_async_event(struct nvme_ctrl *ctrl)
1088 {
1089 	struct nvme_dev *dev = to_nvme_dev(ctrl);
1090 	struct nvme_queue *nvmeq = &dev->queues[0];
1091 	struct nvme_command c;
1092 
1093 	memset(&c, 0, sizeof(c));
1094 	c.common.opcode = nvme_admin_async_event;
1095 	c.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
1096 	nvme_submit_cmd(nvmeq, &c, true);
1097 }
1098 
1099 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
1100 {
1101 	struct nvme_command c;
1102 
1103 	memset(&c, 0, sizeof(c));
1104 	c.delete_queue.opcode = opcode;
1105 	c.delete_queue.qid = cpu_to_le16(id);
1106 
1107 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1108 }
1109 
1110 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
1111 		struct nvme_queue *nvmeq, s16 vector)
1112 {
1113 	struct nvme_command c;
1114 	int flags = NVME_QUEUE_PHYS_CONTIG;
1115 
1116 	if (!test_bit(NVMEQ_POLLED, &nvmeq->flags))
1117 		flags |= NVME_CQ_IRQ_ENABLED;
1118 
1119 	/*
1120 	 * Note: we (ab)use the fact that the prp fields survive if no data
1121 	 * is attached to the request.
1122 	 */
1123 	memset(&c, 0, sizeof(c));
1124 	c.create_cq.opcode = nvme_admin_create_cq;
1125 	c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
1126 	c.create_cq.cqid = cpu_to_le16(qid);
1127 	c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
1128 	c.create_cq.cq_flags = cpu_to_le16(flags);
1129 	c.create_cq.irq_vector = cpu_to_le16(vector);
1130 
1131 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1132 }
1133 
1134 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
1135 						struct nvme_queue *nvmeq)
1136 {
1137 	struct nvme_ctrl *ctrl = &dev->ctrl;
1138 	struct nvme_command c;
1139 	int flags = NVME_QUEUE_PHYS_CONTIG;
1140 
1141 	/*
1142 	 * Some drives have a bug that auto-enables WRRU if MEDIUM isn't
1143 	 * set. Since URGENT priority is zeroes, it makes all queues
1144 	 * URGENT.
1145 	 */
1146 	if (ctrl->quirks & NVME_QUIRK_MEDIUM_PRIO_SQ)
1147 		flags |= NVME_SQ_PRIO_MEDIUM;
1148 
1149 	/*
1150 	 * Note: we (ab)use the fact that the prp fields survive if no data
1151 	 * is attached to the request.
1152 	 */
1153 	memset(&c, 0, sizeof(c));
1154 	c.create_sq.opcode = nvme_admin_create_sq;
1155 	c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
1156 	c.create_sq.sqid = cpu_to_le16(qid);
1157 	c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
1158 	c.create_sq.sq_flags = cpu_to_le16(flags);
1159 	c.create_sq.cqid = cpu_to_le16(qid);
1160 
1161 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1162 }
1163 
1164 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
1165 {
1166 	return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
1167 }
1168 
1169 static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
1170 {
1171 	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
1172 }
1173 
1174 static void abort_endio(struct request *req, blk_status_t error)
1175 {
1176 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
1177 	struct nvme_queue *nvmeq = iod->nvmeq;
1178 
1179 	dev_warn(nvmeq->dev->ctrl.device,
1180 		 "Abort status: 0x%x", nvme_req(req)->status);
1181 	atomic_inc(&nvmeq->dev->ctrl.abort_limit);
1182 	blk_mq_free_request(req);
1183 }
1184 
1185 static bool nvme_should_reset(struct nvme_dev *dev, u32 csts)
1186 {
1187 
1188 	/* If true, indicates loss of adapter communication, possibly by a
1189 	 * NVMe Subsystem reset.
1190 	 */
1191 	bool nssro = dev->subsystem && (csts & NVME_CSTS_NSSRO);
1192 
1193 	/* If there is a reset/reinit ongoing, we shouldn't reset again. */
1194 	switch (dev->ctrl.state) {
1195 	case NVME_CTRL_RESETTING:
1196 	case NVME_CTRL_CONNECTING:
1197 		return false;
1198 	default:
1199 		break;
1200 	}
1201 
1202 	/* We shouldn't reset unless the controller is on fatal error state
1203 	 * _or_ if we lost the communication with it.
1204 	 */
1205 	if (!(csts & NVME_CSTS_CFS) && !nssro)
1206 		return false;
1207 
1208 	return true;
1209 }
1210 
1211 static void nvme_warn_reset(struct nvme_dev *dev, u32 csts)
1212 {
1213 	/* Read a config register to help see what died. */
1214 	u16 pci_status;
1215 	int result;
1216 
1217 	result = pci_read_config_word(to_pci_dev(dev->dev), PCI_STATUS,
1218 				      &pci_status);
1219 	if (result == PCIBIOS_SUCCESSFUL)
1220 		dev_warn(dev->ctrl.device,
1221 			 "controller is down; will reset: CSTS=0x%x, PCI_STATUS=0x%hx\n",
1222 			 csts, pci_status);
1223 	else
1224 		dev_warn(dev->ctrl.device,
1225 			 "controller is down; will reset: CSTS=0x%x, PCI_STATUS read failed (%d)\n",
1226 			 csts, result);
1227 }
1228 
1229 static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
1230 {
1231 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
1232 	struct nvme_queue *nvmeq = iod->nvmeq;
1233 	struct nvme_dev *dev = nvmeq->dev;
1234 	struct request *abort_req;
1235 	struct nvme_command cmd;
1236 	u32 csts = readl(dev->bar + NVME_REG_CSTS);
1237 
1238 	/* If PCI error recovery process is happening, we cannot reset or
1239 	 * the recovery mechanism will surely fail.
1240 	 */
1241 	mb();
1242 	if (pci_channel_offline(to_pci_dev(dev->dev)))
1243 		return BLK_EH_RESET_TIMER;
1244 
1245 	/*
1246 	 * Reset immediately if the controller is failed
1247 	 */
1248 	if (nvme_should_reset(dev, csts)) {
1249 		nvme_warn_reset(dev, csts);
1250 		nvme_dev_disable(dev, false);
1251 		nvme_reset_ctrl(&dev->ctrl);
1252 		return BLK_EH_DONE;
1253 	}
1254 
1255 	/*
1256 	 * Did we miss an interrupt?
1257 	 */
1258 	if (nvme_poll_irqdisable(nvmeq, req->tag)) {
1259 		dev_warn(dev->ctrl.device,
1260 			 "I/O %d QID %d timeout, completion polled\n",
1261 			 req->tag, nvmeq->qid);
1262 		return BLK_EH_DONE;
1263 	}
1264 
1265 	/*
1266 	 * Shutdown immediately if controller times out while starting. The
1267 	 * reset work will see the pci device disabled when it gets the forced
1268 	 * cancellation error. All outstanding requests are completed on
1269 	 * shutdown, so we return BLK_EH_DONE.
1270 	 */
1271 	switch (dev->ctrl.state) {
1272 	case NVME_CTRL_CONNECTING:
1273 		nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING);
1274 		/* fall through */
1275 	case NVME_CTRL_DELETING:
1276 		dev_warn_ratelimited(dev->ctrl.device,
1277 			 "I/O %d QID %d timeout, disable controller\n",
1278 			 req->tag, nvmeq->qid);
1279 		nvme_dev_disable(dev, true);
1280 		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
1281 		return BLK_EH_DONE;
1282 	case NVME_CTRL_RESETTING:
1283 		return BLK_EH_RESET_TIMER;
1284 	default:
1285 		break;
1286 	}
1287 
1288 	/*
1289  	 * Shutdown the controller immediately and schedule a reset if the
1290  	 * command was already aborted once before and still hasn't been
1291  	 * returned to the driver, or if this is the admin queue.
1292 	 */
1293 	if (!nvmeq->qid || iod->aborted) {
1294 		dev_warn(dev->ctrl.device,
1295 			 "I/O %d QID %d timeout, reset controller\n",
1296 			 req->tag, nvmeq->qid);
1297 		nvme_dev_disable(dev, false);
1298 		nvme_reset_ctrl(&dev->ctrl);
1299 
1300 		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
1301 		return BLK_EH_DONE;
1302 	}
1303 
1304 	if (atomic_dec_return(&dev->ctrl.abort_limit) < 0) {
1305 		atomic_inc(&dev->ctrl.abort_limit);
1306 		return BLK_EH_RESET_TIMER;
1307 	}
1308 	iod->aborted = 1;
1309 
1310 	memset(&cmd, 0, sizeof(cmd));
1311 	cmd.abort.opcode = nvme_admin_abort_cmd;
1312 	cmd.abort.cid = req->tag;
1313 	cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
1314 
1315 	dev_warn(nvmeq->dev->ctrl.device,
1316 		"I/O %d QID %d timeout, aborting\n",
1317 		 req->tag, nvmeq->qid);
1318 
1319 	abort_req = nvme_alloc_request(dev->ctrl.admin_q, &cmd,
1320 			BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
1321 	if (IS_ERR(abort_req)) {
1322 		atomic_inc(&dev->ctrl.abort_limit);
1323 		return BLK_EH_RESET_TIMER;
1324 	}
1325 
1326 	abort_req->timeout = ADMIN_TIMEOUT;
1327 	abort_req->end_io_data = NULL;
1328 	blk_execute_rq_nowait(abort_req->q, NULL, abort_req, 0, abort_endio);
1329 
1330 	/*
1331 	 * The aborted req will be completed on receiving the abort req.
1332 	 * We enable the timer again. If hit twice, it'll cause a device reset,
1333 	 * as the device then is in a faulty state.
1334 	 */
1335 	return BLK_EH_RESET_TIMER;
1336 }
1337 
1338 static void nvme_free_queue(struct nvme_queue *nvmeq)
1339 {
1340 	dma_free_coherent(nvmeq->dev->dev, CQ_SIZE(nvmeq),
1341 				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
1342 	if (!nvmeq->sq_cmds)
1343 		return;
1344 
1345 	if (test_and_clear_bit(NVMEQ_SQ_CMB, &nvmeq->flags)) {
1346 		pci_free_p2pmem(to_pci_dev(nvmeq->dev->dev),
1347 				nvmeq->sq_cmds, SQ_SIZE(nvmeq));
1348 	} else {
1349 		dma_free_coherent(nvmeq->dev->dev, SQ_SIZE(nvmeq),
1350 				nvmeq->sq_cmds, nvmeq->sq_dma_addr);
1351 	}
1352 }
1353 
1354 static void nvme_free_queues(struct nvme_dev *dev, int lowest)
1355 {
1356 	int i;
1357 
1358 	for (i = dev->ctrl.queue_count - 1; i >= lowest; i--) {
1359 		dev->ctrl.queue_count--;
1360 		nvme_free_queue(&dev->queues[i]);
1361 	}
1362 }
1363 
1364 /**
1365  * nvme_suspend_queue - put queue into suspended state
1366  * @nvmeq: queue to suspend
1367  */
1368 static int nvme_suspend_queue(struct nvme_queue *nvmeq)
1369 {
1370 	if (!test_and_clear_bit(NVMEQ_ENABLED, &nvmeq->flags))
1371 		return 1;
1372 
1373 	/* ensure that nvme_queue_rq() sees NVMEQ_ENABLED cleared */
1374 	mb();
1375 
1376 	nvmeq->dev->online_queues--;
1377 	if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
1378 		blk_mq_quiesce_queue(nvmeq->dev->ctrl.admin_q);
1379 	if (!test_and_clear_bit(NVMEQ_POLLED, &nvmeq->flags))
1380 		pci_free_irq(to_pci_dev(nvmeq->dev->dev), nvmeq->cq_vector, nvmeq);
1381 	return 0;
1382 }
1383 
1384 static void nvme_suspend_io_queues(struct nvme_dev *dev)
1385 {
1386 	int i;
1387 
1388 	for (i = dev->ctrl.queue_count - 1; i > 0; i--)
1389 		nvme_suspend_queue(&dev->queues[i]);
1390 }
1391 
1392 static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
1393 {
1394 	struct nvme_queue *nvmeq = &dev->queues[0];
1395 
1396 	if (shutdown)
1397 		nvme_shutdown_ctrl(&dev->ctrl);
1398 	else
1399 		nvme_disable_ctrl(&dev->ctrl);
1400 
1401 	nvme_poll_irqdisable(nvmeq, -1);
1402 }
1403 
1404 static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues,
1405 				int entry_size)
1406 {
1407 	int q_depth = dev->q_depth;
1408 	unsigned q_size_aligned = roundup(q_depth * entry_size,
1409 					  dev->ctrl.page_size);
1410 
1411 	if (q_size_aligned * nr_io_queues > dev->cmb_size) {
1412 		u64 mem_per_q = div_u64(dev->cmb_size, nr_io_queues);
1413 		mem_per_q = round_down(mem_per_q, dev->ctrl.page_size);
1414 		q_depth = div_u64(mem_per_q, entry_size);
1415 
1416 		/*
1417 		 * Ensure the reduced q_depth is above some threshold where it
1418 		 * would be better to map queues in system memory with the
1419 		 * original depth
1420 		 */
1421 		if (q_depth < 64)
1422 			return -ENOMEM;
1423 	}
1424 
1425 	return q_depth;
1426 }
1427 
1428 static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
1429 				int qid)
1430 {
1431 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1432 
1433 	if (qid && dev->cmb_use_sqes && (dev->cmbsz & NVME_CMBSZ_SQS)) {
1434 		nvmeq->sq_cmds = pci_alloc_p2pmem(pdev, SQ_SIZE(nvmeq));
1435 		if (nvmeq->sq_cmds) {
1436 			nvmeq->sq_dma_addr = pci_p2pmem_virt_to_bus(pdev,
1437 							nvmeq->sq_cmds);
1438 			if (nvmeq->sq_dma_addr) {
1439 				set_bit(NVMEQ_SQ_CMB, &nvmeq->flags);
1440 				return 0;
1441 			}
1442 
1443 			pci_free_p2pmem(pdev, nvmeq->sq_cmds, SQ_SIZE(nvmeq));
1444 		}
1445 	}
1446 
1447 	nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(nvmeq),
1448 				&nvmeq->sq_dma_addr, GFP_KERNEL);
1449 	if (!nvmeq->sq_cmds)
1450 		return -ENOMEM;
1451 	return 0;
1452 }
1453 
1454 static int nvme_alloc_queue(struct nvme_dev *dev, int qid, int depth)
1455 {
1456 	struct nvme_queue *nvmeq = &dev->queues[qid];
1457 
1458 	if (dev->ctrl.queue_count > qid)
1459 		return 0;
1460 
1461 	nvmeq->sqes = qid ? dev->io_sqes : NVME_ADM_SQES;
1462 	nvmeq->q_depth = depth;
1463 	nvmeq->cqes = dma_alloc_coherent(dev->dev, CQ_SIZE(nvmeq),
1464 					 &nvmeq->cq_dma_addr, GFP_KERNEL);
1465 	if (!nvmeq->cqes)
1466 		goto free_nvmeq;
1467 
1468 	if (nvme_alloc_sq_cmds(dev, nvmeq, qid))
1469 		goto free_cqdma;
1470 
1471 	nvmeq->dev = dev;
1472 	spin_lock_init(&nvmeq->sq_lock);
1473 	spin_lock_init(&nvmeq->cq_poll_lock);
1474 	nvmeq->cq_head = 0;
1475 	nvmeq->cq_phase = 1;
1476 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1477 	nvmeq->qid = qid;
1478 	dev->ctrl.queue_count++;
1479 
1480 	return 0;
1481 
1482  free_cqdma:
1483 	dma_free_coherent(dev->dev, CQ_SIZE(nvmeq), (void *)nvmeq->cqes,
1484 			  nvmeq->cq_dma_addr);
1485  free_nvmeq:
1486 	return -ENOMEM;
1487 }
1488 
1489 static int queue_request_irq(struct nvme_queue *nvmeq)
1490 {
1491 	struct pci_dev *pdev = to_pci_dev(nvmeq->dev->dev);
1492 	int nr = nvmeq->dev->ctrl.instance;
1493 
1494 	if (use_threaded_interrupts) {
1495 		return pci_request_irq(pdev, nvmeq->cq_vector, nvme_irq_check,
1496 				nvme_irq, nvmeq, "nvme%dq%d", nr, nvmeq->qid);
1497 	} else {
1498 		return pci_request_irq(pdev, nvmeq->cq_vector, nvme_irq,
1499 				NULL, nvmeq, "nvme%dq%d", nr, nvmeq->qid);
1500 	}
1501 }
1502 
1503 static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
1504 {
1505 	struct nvme_dev *dev = nvmeq->dev;
1506 
1507 	nvmeq->sq_tail = 0;
1508 	nvmeq->last_sq_tail = 0;
1509 	nvmeq->cq_head = 0;
1510 	nvmeq->cq_phase = 1;
1511 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1512 	memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq));
1513 	nvme_dbbuf_init(dev, nvmeq, qid);
1514 	dev->online_queues++;
1515 	wmb(); /* ensure the first interrupt sees the initialization */
1516 }
1517 
1518 static int nvme_create_queue(struct nvme_queue *nvmeq, int qid, bool polled)
1519 {
1520 	struct nvme_dev *dev = nvmeq->dev;
1521 	int result;
1522 	u16 vector = 0;
1523 
1524 	clear_bit(NVMEQ_DELETE_ERROR, &nvmeq->flags);
1525 
1526 	/*
1527 	 * A queue's vector matches the queue identifier unless the controller
1528 	 * has only one vector available.
1529 	 */
1530 	if (!polled)
1531 		vector = dev->num_vecs == 1 ? 0 : qid;
1532 	else
1533 		set_bit(NVMEQ_POLLED, &nvmeq->flags);
1534 
1535 	result = adapter_alloc_cq(dev, qid, nvmeq, vector);
1536 	if (result)
1537 		return result;
1538 
1539 	result = adapter_alloc_sq(dev, qid, nvmeq);
1540 	if (result < 0)
1541 		return result;
1542 	if (result)
1543 		goto release_cq;
1544 
1545 	nvmeq->cq_vector = vector;
1546 	nvme_init_queue(nvmeq, qid);
1547 
1548 	if (!polled) {
1549 		result = queue_request_irq(nvmeq);
1550 		if (result < 0)
1551 			goto release_sq;
1552 	}
1553 
1554 	set_bit(NVMEQ_ENABLED, &nvmeq->flags);
1555 	return result;
1556 
1557 release_sq:
1558 	dev->online_queues--;
1559 	adapter_delete_sq(dev, qid);
1560 release_cq:
1561 	adapter_delete_cq(dev, qid);
1562 	return result;
1563 }
1564 
1565 static const struct blk_mq_ops nvme_mq_admin_ops = {
1566 	.queue_rq	= nvme_queue_rq,
1567 	.complete	= nvme_pci_complete_rq,
1568 	.init_hctx	= nvme_admin_init_hctx,
1569 	.init_request	= nvme_init_request,
1570 	.timeout	= nvme_timeout,
1571 };
1572 
1573 static const struct blk_mq_ops nvme_mq_ops = {
1574 	.queue_rq	= nvme_queue_rq,
1575 	.complete	= nvme_pci_complete_rq,
1576 	.commit_rqs	= nvme_commit_rqs,
1577 	.init_hctx	= nvme_init_hctx,
1578 	.init_request	= nvme_init_request,
1579 	.map_queues	= nvme_pci_map_queues,
1580 	.timeout	= nvme_timeout,
1581 	.poll		= nvme_poll,
1582 };
1583 
1584 static void nvme_dev_remove_admin(struct nvme_dev *dev)
1585 {
1586 	if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q)) {
1587 		/*
1588 		 * If the controller was reset during removal, it's possible
1589 		 * user requests may be waiting on a stopped queue. Start the
1590 		 * queue to flush these to completion.
1591 		 */
1592 		blk_mq_unquiesce_queue(dev->ctrl.admin_q);
1593 		blk_cleanup_queue(dev->ctrl.admin_q);
1594 		blk_mq_free_tag_set(&dev->admin_tagset);
1595 	}
1596 }
1597 
1598 static int nvme_alloc_admin_tags(struct nvme_dev *dev)
1599 {
1600 	if (!dev->ctrl.admin_q) {
1601 		dev->admin_tagset.ops = &nvme_mq_admin_ops;
1602 		dev->admin_tagset.nr_hw_queues = 1;
1603 
1604 		dev->admin_tagset.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
1605 		dev->admin_tagset.timeout = ADMIN_TIMEOUT;
1606 		dev->admin_tagset.numa_node = dev_to_node(dev->dev);
1607 		dev->admin_tagset.cmd_size = sizeof(struct nvme_iod);
1608 		dev->admin_tagset.flags = BLK_MQ_F_NO_SCHED;
1609 		dev->admin_tagset.driver_data = dev;
1610 
1611 		if (blk_mq_alloc_tag_set(&dev->admin_tagset))
1612 			return -ENOMEM;
1613 		dev->ctrl.admin_tagset = &dev->admin_tagset;
1614 
1615 		dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
1616 		if (IS_ERR(dev->ctrl.admin_q)) {
1617 			blk_mq_free_tag_set(&dev->admin_tagset);
1618 			return -ENOMEM;
1619 		}
1620 		if (!blk_get_queue(dev->ctrl.admin_q)) {
1621 			nvme_dev_remove_admin(dev);
1622 			dev->ctrl.admin_q = NULL;
1623 			return -ENODEV;
1624 		}
1625 	} else
1626 		blk_mq_unquiesce_queue(dev->ctrl.admin_q);
1627 
1628 	return 0;
1629 }
1630 
1631 static unsigned long db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
1632 {
1633 	return NVME_REG_DBS + ((nr_io_queues + 1) * 8 * dev->db_stride);
1634 }
1635 
1636 static int nvme_remap_bar(struct nvme_dev *dev, unsigned long size)
1637 {
1638 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1639 
1640 	if (size <= dev->bar_mapped_size)
1641 		return 0;
1642 	if (size > pci_resource_len(pdev, 0))
1643 		return -ENOMEM;
1644 	if (dev->bar)
1645 		iounmap(dev->bar);
1646 	dev->bar = ioremap(pci_resource_start(pdev, 0), size);
1647 	if (!dev->bar) {
1648 		dev->bar_mapped_size = 0;
1649 		return -ENOMEM;
1650 	}
1651 	dev->bar_mapped_size = size;
1652 	dev->dbs = dev->bar + NVME_REG_DBS;
1653 
1654 	return 0;
1655 }
1656 
1657 static int nvme_pci_configure_admin_queue(struct nvme_dev *dev)
1658 {
1659 	int result;
1660 	u32 aqa;
1661 	struct nvme_queue *nvmeq;
1662 
1663 	result = nvme_remap_bar(dev, db_bar_size(dev, 0));
1664 	if (result < 0)
1665 		return result;
1666 
1667 	dev->subsystem = readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 1, 0) ?
1668 				NVME_CAP_NSSRC(dev->ctrl.cap) : 0;
1669 
1670 	if (dev->subsystem &&
1671 	    (readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_NSSRO))
1672 		writel(NVME_CSTS_NSSRO, dev->bar + NVME_REG_CSTS);
1673 
1674 	result = nvme_disable_ctrl(&dev->ctrl);
1675 	if (result < 0)
1676 		return result;
1677 
1678 	result = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH);
1679 	if (result)
1680 		return result;
1681 
1682 	nvmeq = &dev->queues[0];
1683 	aqa = nvmeq->q_depth - 1;
1684 	aqa |= aqa << 16;
1685 
1686 	writel(aqa, dev->bar + NVME_REG_AQA);
1687 	lo_hi_writeq(nvmeq->sq_dma_addr, dev->bar + NVME_REG_ASQ);
1688 	lo_hi_writeq(nvmeq->cq_dma_addr, dev->bar + NVME_REG_ACQ);
1689 
1690 	result = nvme_enable_ctrl(&dev->ctrl);
1691 	if (result)
1692 		return result;
1693 
1694 	nvmeq->cq_vector = 0;
1695 	nvme_init_queue(nvmeq, 0);
1696 	result = queue_request_irq(nvmeq);
1697 	if (result) {
1698 		dev->online_queues--;
1699 		return result;
1700 	}
1701 
1702 	set_bit(NVMEQ_ENABLED, &nvmeq->flags);
1703 	return result;
1704 }
1705 
1706 static int nvme_create_io_queues(struct nvme_dev *dev)
1707 {
1708 	unsigned i, max, rw_queues;
1709 	int ret = 0;
1710 
1711 	for (i = dev->ctrl.queue_count; i <= dev->max_qid; i++) {
1712 		if (nvme_alloc_queue(dev, i, dev->q_depth)) {
1713 			ret = -ENOMEM;
1714 			break;
1715 		}
1716 	}
1717 
1718 	max = min(dev->max_qid, dev->ctrl.queue_count - 1);
1719 	if (max != 1 && dev->io_queues[HCTX_TYPE_POLL]) {
1720 		rw_queues = dev->io_queues[HCTX_TYPE_DEFAULT] +
1721 				dev->io_queues[HCTX_TYPE_READ];
1722 	} else {
1723 		rw_queues = max;
1724 	}
1725 
1726 	for (i = dev->online_queues; i <= max; i++) {
1727 		bool polled = i > rw_queues;
1728 
1729 		ret = nvme_create_queue(&dev->queues[i], i, polled);
1730 		if (ret)
1731 			break;
1732 	}
1733 
1734 	/*
1735 	 * Ignore failing Create SQ/CQ commands, we can continue with less
1736 	 * than the desired amount of queues, and even a controller without
1737 	 * I/O queues can still be used to issue admin commands.  This might
1738 	 * be useful to upgrade a buggy firmware for example.
1739 	 */
1740 	return ret >= 0 ? 0 : ret;
1741 }
1742 
1743 static ssize_t nvme_cmb_show(struct device *dev,
1744 			     struct device_attribute *attr,
1745 			     char *buf)
1746 {
1747 	struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
1748 
1749 	return scnprintf(buf, PAGE_SIZE, "cmbloc : x%08x\ncmbsz  : x%08x\n",
1750 		       ndev->cmbloc, ndev->cmbsz);
1751 }
1752 static DEVICE_ATTR(cmb, S_IRUGO, nvme_cmb_show, NULL);
1753 
1754 static u64 nvme_cmb_size_unit(struct nvme_dev *dev)
1755 {
1756 	u8 szu = (dev->cmbsz >> NVME_CMBSZ_SZU_SHIFT) & NVME_CMBSZ_SZU_MASK;
1757 
1758 	return 1ULL << (12 + 4 * szu);
1759 }
1760 
1761 static u32 nvme_cmb_size(struct nvme_dev *dev)
1762 {
1763 	return (dev->cmbsz >> NVME_CMBSZ_SZ_SHIFT) & NVME_CMBSZ_SZ_MASK;
1764 }
1765 
1766 static void nvme_map_cmb(struct nvme_dev *dev)
1767 {
1768 	u64 size, offset;
1769 	resource_size_t bar_size;
1770 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1771 	int bar;
1772 
1773 	if (dev->cmb_size)
1774 		return;
1775 
1776 	dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
1777 	if (!dev->cmbsz)
1778 		return;
1779 	dev->cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
1780 
1781 	size = nvme_cmb_size_unit(dev) * nvme_cmb_size(dev);
1782 	offset = nvme_cmb_size_unit(dev) * NVME_CMB_OFST(dev->cmbloc);
1783 	bar = NVME_CMB_BIR(dev->cmbloc);
1784 	bar_size = pci_resource_len(pdev, bar);
1785 
1786 	if (offset > bar_size)
1787 		return;
1788 
1789 	/*
1790 	 * Controllers may support a CMB size larger than their BAR,
1791 	 * for example, due to being behind a bridge. Reduce the CMB to
1792 	 * the reported size of the BAR
1793 	 */
1794 	if (size > bar_size - offset)
1795 		size = bar_size - offset;
1796 
1797 	if (pci_p2pdma_add_resource(pdev, bar, size, offset)) {
1798 		dev_warn(dev->ctrl.device,
1799 			 "failed to register the CMB\n");
1800 		return;
1801 	}
1802 
1803 	dev->cmb_size = size;
1804 	dev->cmb_use_sqes = use_cmb_sqes && (dev->cmbsz & NVME_CMBSZ_SQS);
1805 
1806 	if ((dev->cmbsz & (NVME_CMBSZ_WDS | NVME_CMBSZ_RDS)) ==
1807 			(NVME_CMBSZ_WDS | NVME_CMBSZ_RDS))
1808 		pci_p2pmem_publish(pdev, true);
1809 
1810 	if (sysfs_add_file_to_group(&dev->ctrl.device->kobj,
1811 				    &dev_attr_cmb.attr, NULL))
1812 		dev_warn(dev->ctrl.device,
1813 			 "failed to add sysfs attribute for CMB\n");
1814 }
1815 
1816 static inline void nvme_release_cmb(struct nvme_dev *dev)
1817 {
1818 	if (dev->cmb_size) {
1819 		sysfs_remove_file_from_group(&dev->ctrl.device->kobj,
1820 					     &dev_attr_cmb.attr, NULL);
1821 		dev->cmb_size = 0;
1822 	}
1823 }
1824 
1825 static int nvme_set_host_mem(struct nvme_dev *dev, u32 bits)
1826 {
1827 	u64 dma_addr = dev->host_mem_descs_dma;
1828 	struct nvme_command c;
1829 	int ret;
1830 
1831 	memset(&c, 0, sizeof(c));
1832 	c.features.opcode	= nvme_admin_set_features;
1833 	c.features.fid		= cpu_to_le32(NVME_FEAT_HOST_MEM_BUF);
1834 	c.features.dword11	= cpu_to_le32(bits);
1835 	c.features.dword12	= cpu_to_le32(dev->host_mem_size >>
1836 					      ilog2(dev->ctrl.page_size));
1837 	c.features.dword13	= cpu_to_le32(lower_32_bits(dma_addr));
1838 	c.features.dword14	= cpu_to_le32(upper_32_bits(dma_addr));
1839 	c.features.dword15	= cpu_to_le32(dev->nr_host_mem_descs);
1840 
1841 	ret = nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1842 	if (ret) {
1843 		dev_warn(dev->ctrl.device,
1844 			 "failed to set host mem (err %d, flags %#x).\n",
1845 			 ret, bits);
1846 	}
1847 	return ret;
1848 }
1849 
1850 static void nvme_free_host_mem(struct nvme_dev *dev)
1851 {
1852 	int i;
1853 
1854 	for (i = 0; i < dev->nr_host_mem_descs; i++) {
1855 		struct nvme_host_mem_buf_desc *desc = &dev->host_mem_descs[i];
1856 		size_t size = le32_to_cpu(desc->size) * dev->ctrl.page_size;
1857 
1858 		dma_free_attrs(dev->dev, size, dev->host_mem_desc_bufs[i],
1859 			       le64_to_cpu(desc->addr),
1860 			       DMA_ATTR_NO_KERNEL_MAPPING | DMA_ATTR_NO_WARN);
1861 	}
1862 
1863 	kfree(dev->host_mem_desc_bufs);
1864 	dev->host_mem_desc_bufs = NULL;
1865 	dma_free_coherent(dev->dev,
1866 			dev->nr_host_mem_descs * sizeof(*dev->host_mem_descs),
1867 			dev->host_mem_descs, dev->host_mem_descs_dma);
1868 	dev->host_mem_descs = NULL;
1869 	dev->nr_host_mem_descs = 0;
1870 }
1871 
1872 static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred,
1873 		u32 chunk_size)
1874 {
1875 	struct nvme_host_mem_buf_desc *descs;
1876 	u32 max_entries, len;
1877 	dma_addr_t descs_dma;
1878 	int i = 0;
1879 	void **bufs;
1880 	u64 size, tmp;
1881 
1882 	tmp = (preferred + chunk_size - 1);
1883 	do_div(tmp, chunk_size);
1884 	max_entries = tmp;
1885 
1886 	if (dev->ctrl.hmmaxd && dev->ctrl.hmmaxd < max_entries)
1887 		max_entries = dev->ctrl.hmmaxd;
1888 
1889 	descs = dma_alloc_coherent(dev->dev, max_entries * sizeof(*descs),
1890 				   &descs_dma, GFP_KERNEL);
1891 	if (!descs)
1892 		goto out;
1893 
1894 	bufs = kcalloc(max_entries, sizeof(*bufs), GFP_KERNEL);
1895 	if (!bufs)
1896 		goto out_free_descs;
1897 
1898 	for (size = 0; size < preferred && i < max_entries; size += len) {
1899 		dma_addr_t dma_addr;
1900 
1901 		len = min_t(u64, chunk_size, preferred - size);
1902 		bufs[i] = dma_alloc_attrs(dev->dev, len, &dma_addr, GFP_KERNEL,
1903 				DMA_ATTR_NO_KERNEL_MAPPING | DMA_ATTR_NO_WARN);
1904 		if (!bufs[i])
1905 			break;
1906 
1907 		descs[i].addr = cpu_to_le64(dma_addr);
1908 		descs[i].size = cpu_to_le32(len / dev->ctrl.page_size);
1909 		i++;
1910 	}
1911 
1912 	if (!size)
1913 		goto out_free_bufs;
1914 
1915 	dev->nr_host_mem_descs = i;
1916 	dev->host_mem_size = size;
1917 	dev->host_mem_descs = descs;
1918 	dev->host_mem_descs_dma = descs_dma;
1919 	dev->host_mem_desc_bufs = bufs;
1920 	return 0;
1921 
1922 out_free_bufs:
1923 	while (--i >= 0) {
1924 		size_t size = le32_to_cpu(descs[i].size) * dev->ctrl.page_size;
1925 
1926 		dma_free_attrs(dev->dev, size, bufs[i],
1927 			       le64_to_cpu(descs[i].addr),
1928 			       DMA_ATTR_NO_KERNEL_MAPPING | DMA_ATTR_NO_WARN);
1929 	}
1930 
1931 	kfree(bufs);
1932 out_free_descs:
1933 	dma_free_coherent(dev->dev, max_entries * sizeof(*descs), descs,
1934 			descs_dma);
1935 out:
1936 	dev->host_mem_descs = NULL;
1937 	return -ENOMEM;
1938 }
1939 
1940 static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred)
1941 {
1942 	u32 chunk_size;
1943 
1944 	/* start big and work our way down */
1945 	for (chunk_size = min_t(u64, preferred, PAGE_SIZE * MAX_ORDER_NR_PAGES);
1946 	     chunk_size >= max_t(u32, dev->ctrl.hmminds * 4096, PAGE_SIZE * 2);
1947 	     chunk_size /= 2) {
1948 		if (!__nvme_alloc_host_mem(dev, preferred, chunk_size)) {
1949 			if (!min || dev->host_mem_size >= min)
1950 				return 0;
1951 			nvme_free_host_mem(dev);
1952 		}
1953 	}
1954 
1955 	return -ENOMEM;
1956 }
1957 
1958 static int nvme_setup_host_mem(struct nvme_dev *dev)
1959 {
1960 	u64 max = (u64)max_host_mem_size_mb * SZ_1M;
1961 	u64 preferred = (u64)dev->ctrl.hmpre * 4096;
1962 	u64 min = (u64)dev->ctrl.hmmin * 4096;
1963 	u32 enable_bits = NVME_HOST_MEM_ENABLE;
1964 	int ret;
1965 
1966 	preferred = min(preferred, max);
1967 	if (min > max) {
1968 		dev_warn(dev->ctrl.device,
1969 			"min host memory (%lld MiB) above limit (%d MiB).\n",
1970 			min >> ilog2(SZ_1M), max_host_mem_size_mb);
1971 		nvme_free_host_mem(dev);
1972 		return 0;
1973 	}
1974 
1975 	/*
1976 	 * If we already have a buffer allocated check if we can reuse it.
1977 	 */
1978 	if (dev->host_mem_descs) {
1979 		if (dev->host_mem_size >= min)
1980 			enable_bits |= NVME_HOST_MEM_RETURN;
1981 		else
1982 			nvme_free_host_mem(dev);
1983 	}
1984 
1985 	if (!dev->host_mem_descs) {
1986 		if (nvme_alloc_host_mem(dev, min, preferred)) {
1987 			dev_warn(dev->ctrl.device,
1988 				"failed to allocate host memory buffer.\n");
1989 			return 0; /* controller must work without HMB */
1990 		}
1991 
1992 		dev_info(dev->ctrl.device,
1993 			"allocated %lld MiB host memory buffer.\n",
1994 			dev->host_mem_size >> ilog2(SZ_1M));
1995 	}
1996 
1997 	ret = nvme_set_host_mem(dev, enable_bits);
1998 	if (ret)
1999 		nvme_free_host_mem(dev);
2000 	return ret;
2001 }
2002 
2003 /*
2004  * nirqs is the number of interrupts available for write and read
2005  * queues. The core already reserved an interrupt for the admin queue.
2006  */
2007 static void nvme_calc_irq_sets(struct irq_affinity *affd, unsigned int nrirqs)
2008 {
2009 	struct nvme_dev *dev = affd->priv;
2010 	unsigned int nr_read_queues;
2011 
2012 	/*
2013 	 * If there is no interupt available for queues, ensure that
2014 	 * the default queue is set to 1. The affinity set size is
2015 	 * also set to one, but the irq core ignores it for this case.
2016 	 *
2017 	 * If only one interrupt is available or 'write_queue' == 0, combine
2018 	 * write and read queues.
2019 	 *
2020 	 * If 'write_queues' > 0, ensure it leaves room for at least one read
2021 	 * queue.
2022 	 */
2023 	if (!nrirqs) {
2024 		nrirqs = 1;
2025 		nr_read_queues = 0;
2026 	} else if (nrirqs == 1 || !write_queues) {
2027 		nr_read_queues = 0;
2028 	} else if (write_queues >= nrirqs) {
2029 		nr_read_queues = 1;
2030 	} else {
2031 		nr_read_queues = nrirqs - write_queues;
2032 	}
2033 
2034 	dev->io_queues[HCTX_TYPE_DEFAULT] = nrirqs - nr_read_queues;
2035 	affd->set_size[HCTX_TYPE_DEFAULT] = nrirqs - nr_read_queues;
2036 	dev->io_queues[HCTX_TYPE_READ] = nr_read_queues;
2037 	affd->set_size[HCTX_TYPE_READ] = nr_read_queues;
2038 	affd->nr_sets = nr_read_queues ? 2 : 1;
2039 }
2040 
2041 static int nvme_setup_irqs(struct nvme_dev *dev, unsigned int nr_io_queues)
2042 {
2043 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2044 	struct irq_affinity affd = {
2045 		.pre_vectors	= 1,
2046 		.calc_sets	= nvme_calc_irq_sets,
2047 		.priv		= dev,
2048 	};
2049 	unsigned int irq_queues, this_p_queues;
2050 
2051 	/*
2052 	 * Poll queues don't need interrupts, but we need at least one IO
2053 	 * queue left over for non-polled IO.
2054 	 */
2055 	this_p_queues = poll_queues;
2056 	if (this_p_queues >= nr_io_queues) {
2057 		this_p_queues = nr_io_queues - 1;
2058 		irq_queues = 1;
2059 	} else {
2060 		irq_queues = nr_io_queues - this_p_queues + 1;
2061 	}
2062 	dev->io_queues[HCTX_TYPE_POLL] = this_p_queues;
2063 
2064 	/* Initialize for the single interrupt case */
2065 	dev->io_queues[HCTX_TYPE_DEFAULT] = 1;
2066 	dev->io_queues[HCTX_TYPE_READ] = 0;
2067 
2068 	/*
2069 	 * Some Apple controllers require all queues to use the
2070 	 * first vector.
2071 	 */
2072 	if (dev->ctrl.quirks & NVME_QUIRK_SINGLE_VECTOR)
2073 		irq_queues = 1;
2074 
2075 	return pci_alloc_irq_vectors_affinity(pdev, 1, irq_queues,
2076 			      PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
2077 }
2078 
2079 static void nvme_disable_io_queues(struct nvme_dev *dev)
2080 {
2081 	if (__nvme_disable_io_queues(dev, nvme_admin_delete_sq))
2082 		__nvme_disable_io_queues(dev, nvme_admin_delete_cq);
2083 }
2084 
2085 static int nvme_setup_io_queues(struct nvme_dev *dev)
2086 {
2087 	struct nvme_queue *adminq = &dev->queues[0];
2088 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2089 	int result, nr_io_queues;
2090 	unsigned long size;
2091 
2092 	nr_io_queues = max_io_queues();
2093 
2094 	/*
2095 	 * If tags are shared with admin queue (Apple bug), then
2096 	 * make sure we only use one IO queue.
2097 	 */
2098 	if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
2099 		nr_io_queues = 1;
2100 
2101 	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
2102 	if (result < 0)
2103 		return result;
2104 
2105 	if (nr_io_queues == 0)
2106 		return 0;
2107 
2108 	clear_bit(NVMEQ_ENABLED, &adminq->flags);
2109 
2110 	if (dev->cmb_use_sqes) {
2111 		result = nvme_cmb_qdepth(dev, nr_io_queues,
2112 				sizeof(struct nvme_command));
2113 		if (result > 0)
2114 			dev->q_depth = result;
2115 		else
2116 			dev->cmb_use_sqes = false;
2117 	}
2118 
2119 	do {
2120 		size = db_bar_size(dev, nr_io_queues);
2121 		result = nvme_remap_bar(dev, size);
2122 		if (!result)
2123 			break;
2124 		if (!--nr_io_queues)
2125 			return -ENOMEM;
2126 	} while (1);
2127 	adminq->q_db = dev->dbs;
2128 
2129  retry:
2130 	/* Deregister the admin queue's interrupt */
2131 	pci_free_irq(pdev, 0, adminq);
2132 
2133 	/*
2134 	 * If we enable msix early due to not intx, disable it again before
2135 	 * setting up the full range we need.
2136 	 */
2137 	pci_free_irq_vectors(pdev);
2138 
2139 	result = nvme_setup_irqs(dev, nr_io_queues);
2140 	if (result <= 0)
2141 		return -EIO;
2142 
2143 	dev->num_vecs = result;
2144 	result = max(result - 1, 1);
2145 	dev->max_qid = result + dev->io_queues[HCTX_TYPE_POLL];
2146 
2147 	/*
2148 	 * Should investigate if there's a performance win from allocating
2149 	 * more queues than interrupt vectors; it might allow the submission
2150 	 * path to scale better, even if the receive path is limited by the
2151 	 * number of interrupts.
2152 	 */
2153 	result = queue_request_irq(adminq);
2154 	if (result)
2155 		return result;
2156 	set_bit(NVMEQ_ENABLED, &adminq->flags);
2157 
2158 	result = nvme_create_io_queues(dev);
2159 	if (result || dev->online_queues < 2)
2160 		return result;
2161 
2162 	if (dev->online_queues - 1 < dev->max_qid) {
2163 		nr_io_queues = dev->online_queues - 1;
2164 		nvme_disable_io_queues(dev);
2165 		nvme_suspend_io_queues(dev);
2166 		goto retry;
2167 	}
2168 	dev_info(dev->ctrl.device, "%d/%d/%d default/read/poll queues\n",
2169 					dev->io_queues[HCTX_TYPE_DEFAULT],
2170 					dev->io_queues[HCTX_TYPE_READ],
2171 					dev->io_queues[HCTX_TYPE_POLL]);
2172 	return 0;
2173 }
2174 
2175 static void nvme_del_queue_end(struct request *req, blk_status_t error)
2176 {
2177 	struct nvme_queue *nvmeq = req->end_io_data;
2178 
2179 	blk_mq_free_request(req);
2180 	complete(&nvmeq->delete_done);
2181 }
2182 
2183 static void nvme_del_cq_end(struct request *req, blk_status_t error)
2184 {
2185 	struct nvme_queue *nvmeq = req->end_io_data;
2186 
2187 	if (error)
2188 		set_bit(NVMEQ_DELETE_ERROR, &nvmeq->flags);
2189 
2190 	nvme_del_queue_end(req, error);
2191 }
2192 
2193 static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
2194 {
2195 	struct request_queue *q = nvmeq->dev->ctrl.admin_q;
2196 	struct request *req;
2197 	struct nvme_command cmd;
2198 
2199 	memset(&cmd, 0, sizeof(cmd));
2200 	cmd.delete_queue.opcode = opcode;
2201 	cmd.delete_queue.qid = cpu_to_le16(nvmeq->qid);
2202 
2203 	req = nvme_alloc_request(q, &cmd, BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
2204 	if (IS_ERR(req))
2205 		return PTR_ERR(req);
2206 
2207 	req->timeout = ADMIN_TIMEOUT;
2208 	req->end_io_data = nvmeq;
2209 
2210 	init_completion(&nvmeq->delete_done);
2211 	blk_execute_rq_nowait(q, NULL, req, false,
2212 			opcode == nvme_admin_delete_cq ?
2213 				nvme_del_cq_end : nvme_del_queue_end);
2214 	return 0;
2215 }
2216 
2217 static bool __nvme_disable_io_queues(struct nvme_dev *dev, u8 opcode)
2218 {
2219 	int nr_queues = dev->online_queues - 1, sent = 0;
2220 	unsigned long timeout;
2221 
2222  retry:
2223 	timeout = ADMIN_TIMEOUT;
2224 	while (nr_queues > 0) {
2225 		if (nvme_delete_queue(&dev->queues[nr_queues], opcode))
2226 			break;
2227 		nr_queues--;
2228 		sent++;
2229 	}
2230 	while (sent) {
2231 		struct nvme_queue *nvmeq = &dev->queues[nr_queues + sent];
2232 
2233 		timeout = wait_for_completion_io_timeout(&nvmeq->delete_done,
2234 				timeout);
2235 		if (timeout == 0)
2236 			return false;
2237 
2238 		/* handle any remaining CQEs */
2239 		if (opcode == nvme_admin_delete_cq &&
2240 		    !test_bit(NVMEQ_DELETE_ERROR, &nvmeq->flags))
2241 			nvme_poll_irqdisable(nvmeq, -1);
2242 
2243 		sent--;
2244 		if (nr_queues)
2245 			goto retry;
2246 	}
2247 	return true;
2248 }
2249 
2250 static void nvme_dev_add(struct nvme_dev *dev)
2251 {
2252 	int ret;
2253 
2254 	if (!dev->ctrl.tagset) {
2255 		dev->tagset.ops = &nvme_mq_ops;
2256 		dev->tagset.nr_hw_queues = dev->online_queues - 1;
2257 		dev->tagset.nr_maps = 2; /* default + read */
2258 		if (dev->io_queues[HCTX_TYPE_POLL])
2259 			dev->tagset.nr_maps++;
2260 		dev->tagset.timeout = NVME_IO_TIMEOUT;
2261 		dev->tagset.numa_node = dev_to_node(dev->dev);
2262 		dev->tagset.queue_depth =
2263 				min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH) - 1;
2264 		dev->tagset.cmd_size = sizeof(struct nvme_iod);
2265 		dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
2266 		dev->tagset.driver_data = dev;
2267 
2268 		/*
2269 		 * Some Apple controllers requires tags to be unique
2270 		 * across admin and IO queue, so reserve the first 32
2271 		 * tags of the IO queue.
2272 		 */
2273 		if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
2274 			dev->tagset.reserved_tags = NVME_AQ_DEPTH;
2275 
2276 		ret = blk_mq_alloc_tag_set(&dev->tagset);
2277 		if (ret) {
2278 			dev_warn(dev->ctrl.device,
2279 				"IO queues tagset allocation failed %d\n", ret);
2280 			return;
2281 		}
2282 		dev->ctrl.tagset = &dev->tagset;
2283 	} else {
2284 		blk_mq_update_nr_hw_queues(&dev->tagset, dev->online_queues - 1);
2285 
2286 		/* Free previously allocated queues that are no longer usable */
2287 		nvme_free_queues(dev, dev->online_queues);
2288 	}
2289 
2290 	nvme_dbbuf_set(dev);
2291 }
2292 
2293 static int nvme_pci_enable(struct nvme_dev *dev)
2294 {
2295 	int result = -ENOMEM;
2296 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2297 
2298 	if (pci_enable_device_mem(pdev))
2299 		return result;
2300 
2301 	pci_set_master(pdev);
2302 
2303 	if (dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(64)))
2304 		goto disable;
2305 
2306 	if (readl(dev->bar + NVME_REG_CSTS) == -1) {
2307 		result = -ENODEV;
2308 		goto disable;
2309 	}
2310 
2311 	/*
2312 	 * Some devices and/or platforms don't advertise or work with INTx
2313 	 * interrupts. Pre-enable a single MSIX or MSI vec for setup. We'll
2314 	 * adjust this later.
2315 	 */
2316 	result = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
2317 	if (result < 0)
2318 		return result;
2319 
2320 	dev->ctrl.cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
2321 
2322 	dev->q_depth = min_t(int, NVME_CAP_MQES(dev->ctrl.cap) + 1,
2323 				io_queue_depth);
2324 	dev->ctrl.sqsize = dev->q_depth - 1; /* 0's based queue depth */
2325 	dev->db_stride = 1 << NVME_CAP_STRIDE(dev->ctrl.cap);
2326 	dev->dbs = dev->bar + 4096;
2327 
2328 	/*
2329 	 * Some Apple controllers require a non-standard SQE size.
2330 	 * Interestingly they also seem to ignore the CC:IOSQES register
2331 	 * so we don't bother updating it here.
2332 	 */
2333 	if (dev->ctrl.quirks & NVME_QUIRK_128_BYTES_SQES)
2334 		dev->io_sqes = 7;
2335 	else
2336 		dev->io_sqes = NVME_NVM_IOSQES;
2337 
2338 	/*
2339 	 * Temporary fix for the Apple controller found in the MacBook8,1 and
2340 	 * some MacBook7,1 to avoid controller resets and data loss.
2341 	 */
2342 	if (pdev->vendor == PCI_VENDOR_ID_APPLE && pdev->device == 0x2001) {
2343 		dev->q_depth = 2;
2344 		dev_warn(dev->ctrl.device, "detected Apple NVMe controller, "
2345 			"set queue depth=%u to work around controller resets\n",
2346 			dev->q_depth);
2347 	} else if (pdev->vendor == PCI_VENDOR_ID_SAMSUNG &&
2348 		   (pdev->device == 0xa821 || pdev->device == 0xa822) &&
2349 		   NVME_CAP_MQES(dev->ctrl.cap) == 0) {
2350 		dev->q_depth = 64;
2351 		dev_err(dev->ctrl.device, "detected PM1725 NVMe controller, "
2352                         "set queue depth=%u\n", dev->q_depth);
2353 	}
2354 
2355 	/*
2356 	 * Controllers with the shared tags quirk need the IO queue to be
2357 	 * big enough so that we get 32 tags for the admin queue
2358 	 */
2359 	if ((dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS) &&
2360 	    (dev->q_depth < (NVME_AQ_DEPTH + 2))) {
2361 		dev->q_depth = NVME_AQ_DEPTH + 2;
2362 		dev_warn(dev->ctrl.device, "IO queue depth clamped to %d\n",
2363 			 dev->q_depth);
2364 	}
2365 
2366 
2367 	nvme_map_cmb(dev);
2368 
2369 	pci_enable_pcie_error_reporting(pdev);
2370 	pci_save_state(pdev);
2371 	return 0;
2372 
2373  disable:
2374 	pci_disable_device(pdev);
2375 	return result;
2376 }
2377 
2378 static void nvme_dev_unmap(struct nvme_dev *dev)
2379 {
2380 	if (dev->bar)
2381 		iounmap(dev->bar);
2382 	pci_release_mem_regions(to_pci_dev(dev->dev));
2383 }
2384 
2385 static void nvme_pci_disable(struct nvme_dev *dev)
2386 {
2387 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2388 
2389 	pci_free_irq_vectors(pdev);
2390 
2391 	if (pci_is_enabled(pdev)) {
2392 		pci_disable_pcie_error_reporting(pdev);
2393 		pci_disable_device(pdev);
2394 	}
2395 }
2396 
2397 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
2398 {
2399 	bool dead = true, freeze = false;
2400 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2401 
2402 	mutex_lock(&dev->shutdown_lock);
2403 	if (pci_is_enabled(pdev)) {
2404 		u32 csts = readl(dev->bar + NVME_REG_CSTS);
2405 
2406 		if (dev->ctrl.state == NVME_CTRL_LIVE ||
2407 		    dev->ctrl.state == NVME_CTRL_RESETTING) {
2408 			freeze = true;
2409 			nvme_start_freeze(&dev->ctrl);
2410 		}
2411 		dead = !!((csts & NVME_CSTS_CFS) || !(csts & NVME_CSTS_RDY) ||
2412 			pdev->error_state  != pci_channel_io_normal);
2413 	}
2414 
2415 	/*
2416 	 * Give the controller a chance to complete all entered requests if
2417 	 * doing a safe shutdown.
2418 	 */
2419 	if (!dead && shutdown && freeze)
2420 		nvme_wait_freeze_timeout(&dev->ctrl, NVME_IO_TIMEOUT);
2421 
2422 	nvme_stop_queues(&dev->ctrl);
2423 
2424 	if (!dead && dev->ctrl.queue_count > 0) {
2425 		nvme_disable_io_queues(dev);
2426 		nvme_disable_admin_queue(dev, shutdown);
2427 	}
2428 	nvme_suspend_io_queues(dev);
2429 	nvme_suspend_queue(&dev->queues[0]);
2430 	nvme_pci_disable(dev);
2431 
2432 	blk_mq_tagset_busy_iter(&dev->tagset, nvme_cancel_request, &dev->ctrl);
2433 	blk_mq_tagset_busy_iter(&dev->admin_tagset, nvme_cancel_request, &dev->ctrl);
2434 	blk_mq_tagset_wait_completed_request(&dev->tagset);
2435 	blk_mq_tagset_wait_completed_request(&dev->admin_tagset);
2436 
2437 	/*
2438 	 * The driver will not be starting up queues again if shutting down so
2439 	 * must flush all entered requests to their failed completion to avoid
2440 	 * deadlocking blk-mq hot-cpu notifier.
2441 	 */
2442 	if (shutdown) {
2443 		nvme_start_queues(&dev->ctrl);
2444 		if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q))
2445 			blk_mq_unquiesce_queue(dev->ctrl.admin_q);
2446 	}
2447 	mutex_unlock(&dev->shutdown_lock);
2448 }
2449 
2450 static int nvme_disable_prepare_reset(struct nvme_dev *dev, bool shutdown)
2451 {
2452 	if (!nvme_wait_reset(&dev->ctrl))
2453 		return -EBUSY;
2454 	nvme_dev_disable(dev, shutdown);
2455 	return 0;
2456 }
2457 
2458 static int nvme_setup_prp_pools(struct nvme_dev *dev)
2459 {
2460 	dev->prp_page_pool = dma_pool_create("prp list page", dev->dev,
2461 						PAGE_SIZE, PAGE_SIZE, 0);
2462 	if (!dev->prp_page_pool)
2463 		return -ENOMEM;
2464 
2465 	/* Optimisation for I/Os between 4k and 128k */
2466 	dev->prp_small_pool = dma_pool_create("prp list 256", dev->dev,
2467 						256, 256, 0);
2468 	if (!dev->prp_small_pool) {
2469 		dma_pool_destroy(dev->prp_page_pool);
2470 		return -ENOMEM;
2471 	}
2472 	return 0;
2473 }
2474 
2475 static void nvme_release_prp_pools(struct nvme_dev *dev)
2476 {
2477 	dma_pool_destroy(dev->prp_page_pool);
2478 	dma_pool_destroy(dev->prp_small_pool);
2479 }
2480 
2481 static void nvme_free_tagset(struct nvme_dev *dev)
2482 {
2483 	if (dev->tagset.tags)
2484 		blk_mq_free_tag_set(&dev->tagset);
2485 	dev->ctrl.tagset = NULL;
2486 }
2487 
2488 static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
2489 {
2490 	struct nvme_dev *dev = to_nvme_dev(ctrl);
2491 
2492 	nvme_dbbuf_dma_free(dev);
2493 	put_device(dev->dev);
2494 	nvme_free_tagset(dev);
2495 	if (dev->ctrl.admin_q)
2496 		blk_put_queue(dev->ctrl.admin_q);
2497 	kfree(dev->queues);
2498 	free_opal_dev(dev->ctrl.opal_dev);
2499 	mempool_destroy(dev->iod_mempool);
2500 	kfree(dev);
2501 }
2502 
2503 static void nvme_remove_dead_ctrl(struct nvme_dev *dev)
2504 {
2505 	/*
2506 	 * Set state to deleting now to avoid blocking nvme_wait_reset(), which
2507 	 * may be holding this pci_dev's device lock.
2508 	 */
2509 	nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING);
2510 	nvme_get_ctrl(&dev->ctrl);
2511 	nvme_dev_disable(dev, false);
2512 	nvme_kill_queues(&dev->ctrl);
2513 	if (!queue_work(nvme_wq, &dev->remove_work))
2514 		nvme_put_ctrl(&dev->ctrl);
2515 }
2516 
2517 static void nvme_reset_work(struct work_struct *work)
2518 {
2519 	struct nvme_dev *dev =
2520 		container_of(work, struct nvme_dev, ctrl.reset_work);
2521 	bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL);
2522 	int result;
2523 
2524 	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING)) {
2525 		result = -ENODEV;
2526 		goto out;
2527 	}
2528 
2529 	/*
2530 	 * If we're called to reset a live controller first shut it down before
2531 	 * moving on.
2532 	 */
2533 	if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
2534 		nvme_dev_disable(dev, false);
2535 	nvme_sync_queues(&dev->ctrl);
2536 
2537 	mutex_lock(&dev->shutdown_lock);
2538 	result = nvme_pci_enable(dev);
2539 	if (result)
2540 		goto out_unlock;
2541 
2542 	result = nvme_pci_configure_admin_queue(dev);
2543 	if (result)
2544 		goto out_unlock;
2545 
2546 	result = nvme_alloc_admin_tags(dev);
2547 	if (result)
2548 		goto out_unlock;
2549 
2550 	/*
2551 	 * Limit the max command size to prevent iod->sg allocations going
2552 	 * over a single page.
2553 	 */
2554 	dev->ctrl.max_hw_sectors = min_t(u32,
2555 		NVME_MAX_KB_SZ << 1, dma_max_mapping_size(dev->dev) >> 9);
2556 	dev->ctrl.max_segments = NVME_MAX_SEGS;
2557 
2558 	/*
2559 	 * Don't limit the IOMMU merged segment size.
2560 	 */
2561 	dma_set_max_seg_size(dev->dev, 0xffffffff);
2562 
2563 	mutex_unlock(&dev->shutdown_lock);
2564 
2565 	/*
2566 	 * Introduce CONNECTING state from nvme-fc/rdma transports to mark the
2567 	 * initializing procedure here.
2568 	 */
2569 	if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_CONNECTING)) {
2570 		dev_warn(dev->ctrl.device,
2571 			"failed to mark controller CONNECTING\n");
2572 		result = -EBUSY;
2573 		goto out;
2574 	}
2575 
2576 	result = nvme_init_identify(&dev->ctrl);
2577 	if (result)
2578 		goto out;
2579 
2580 	if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
2581 		if (!dev->ctrl.opal_dev)
2582 			dev->ctrl.opal_dev =
2583 				init_opal_dev(&dev->ctrl, &nvme_sec_submit);
2584 		else if (was_suspend)
2585 			opal_unlock_from_suspend(dev->ctrl.opal_dev);
2586 	} else {
2587 		free_opal_dev(dev->ctrl.opal_dev);
2588 		dev->ctrl.opal_dev = NULL;
2589 	}
2590 
2591 	if (dev->ctrl.oacs & NVME_CTRL_OACS_DBBUF_SUPP) {
2592 		result = nvme_dbbuf_dma_alloc(dev);
2593 		if (result)
2594 			dev_warn(dev->dev,
2595 				 "unable to allocate dma for dbbuf\n");
2596 	}
2597 
2598 	if (dev->ctrl.hmpre) {
2599 		result = nvme_setup_host_mem(dev);
2600 		if (result < 0)
2601 			goto out;
2602 	}
2603 
2604 	result = nvme_setup_io_queues(dev);
2605 	if (result)
2606 		goto out;
2607 
2608 	/*
2609 	 * Keep the controller around but remove all namespaces if we don't have
2610 	 * any working I/O queue.
2611 	 */
2612 	if (dev->online_queues < 2) {
2613 		dev_warn(dev->ctrl.device, "IO queues not created\n");
2614 		nvme_kill_queues(&dev->ctrl);
2615 		nvme_remove_namespaces(&dev->ctrl);
2616 		nvme_free_tagset(dev);
2617 	} else {
2618 		nvme_start_queues(&dev->ctrl);
2619 		nvme_wait_freeze(&dev->ctrl);
2620 		nvme_dev_add(dev);
2621 		nvme_unfreeze(&dev->ctrl);
2622 	}
2623 
2624 	/*
2625 	 * If only admin queue live, keep it to do further investigation or
2626 	 * recovery.
2627 	 */
2628 	if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_LIVE)) {
2629 		dev_warn(dev->ctrl.device,
2630 			"failed to mark controller live state\n");
2631 		result = -ENODEV;
2632 		goto out;
2633 	}
2634 
2635 	nvme_start_ctrl(&dev->ctrl);
2636 	return;
2637 
2638  out_unlock:
2639 	mutex_unlock(&dev->shutdown_lock);
2640  out:
2641 	if (result)
2642 		dev_warn(dev->ctrl.device,
2643 			 "Removing after probe failure status: %d\n", result);
2644 	nvme_remove_dead_ctrl(dev);
2645 }
2646 
2647 static void nvme_remove_dead_ctrl_work(struct work_struct *work)
2648 {
2649 	struct nvme_dev *dev = container_of(work, struct nvme_dev, remove_work);
2650 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2651 
2652 	if (pci_get_drvdata(pdev))
2653 		device_release_driver(&pdev->dev);
2654 	nvme_put_ctrl(&dev->ctrl);
2655 }
2656 
2657 static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
2658 {
2659 	*val = readl(to_nvme_dev(ctrl)->bar + off);
2660 	return 0;
2661 }
2662 
2663 static int nvme_pci_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
2664 {
2665 	writel(val, to_nvme_dev(ctrl)->bar + off);
2666 	return 0;
2667 }
2668 
2669 static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
2670 {
2671 	*val = lo_hi_readq(to_nvme_dev(ctrl)->bar + off);
2672 	return 0;
2673 }
2674 
2675 static int nvme_pci_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
2676 {
2677 	struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev);
2678 
2679 	return snprintf(buf, size, "%s", dev_name(&pdev->dev));
2680 }
2681 
2682 static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
2683 	.name			= "pcie",
2684 	.module			= THIS_MODULE,
2685 	.flags			= NVME_F_METADATA_SUPPORTED |
2686 				  NVME_F_PCI_P2PDMA,
2687 	.reg_read32		= nvme_pci_reg_read32,
2688 	.reg_write32		= nvme_pci_reg_write32,
2689 	.reg_read64		= nvme_pci_reg_read64,
2690 	.free_ctrl		= nvme_pci_free_ctrl,
2691 	.submit_async_event	= nvme_pci_submit_async_event,
2692 	.get_address		= nvme_pci_get_address,
2693 };
2694 
2695 static int nvme_dev_map(struct nvme_dev *dev)
2696 {
2697 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2698 
2699 	if (pci_request_mem_regions(pdev, "nvme"))
2700 		return -ENODEV;
2701 
2702 	if (nvme_remap_bar(dev, NVME_REG_DBS + 4096))
2703 		goto release;
2704 
2705 	return 0;
2706   release:
2707 	pci_release_mem_regions(pdev);
2708 	return -ENODEV;
2709 }
2710 
2711 static unsigned long check_vendor_combination_bug(struct pci_dev *pdev)
2712 {
2713 	if (pdev->vendor == 0x144d && pdev->device == 0xa802) {
2714 		/*
2715 		 * Several Samsung devices seem to drop off the PCIe bus
2716 		 * randomly when APST is on and uses the deepest sleep state.
2717 		 * This has been observed on a Samsung "SM951 NVMe SAMSUNG
2718 		 * 256GB", a "PM951 NVMe SAMSUNG 512GB", and a "Samsung SSD
2719 		 * 950 PRO 256GB", but it seems to be restricted to two Dell
2720 		 * laptops.
2721 		 */
2722 		if (dmi_match(DMI_SYS_VENDOR, "Dell Inc.") &&
2723 		    (dmi_match(DMI_PRODUCT_NAME, "XPS 15 9550") ||
2724 		     dmi_match(DMI_PRODUCT_NAME, "Precision 5510")))
2725 			return NVME_QUIRK_NO_DEEPEST_PS;
2726 	} else if (pdev->vendor == 0x144d && pdev->device == 0xa804) {
2727 		/*
2728 		 * Samsung SSD 960 EVO drops off the PCIe bus after system
2729 		 * suspend on a Ryzen board, ASUS PRIME B350M-A, as well as
2730 		 * within few minutes after bootup on a Coffee Lake board -
2731 		 * ASUS PRIME Z370-A
2732 		 */
2733 		if (dmi_match(DMI_BOARD_VENDOR, "ASUSTeK COMPUTER INC.") &&
2734 		    (dmi_match(DMI_BOARD_NAME, "PRIME B350M-A") ||
2735 		     dmi_match(DMI_BOARD_NAME, "PRIME Z370-A")))
2736 			return NVME_QUIRK_NO_APST;
2737 	}
2738 
2739 	return 0;
2740 }
2741 
2742 static void nvme_async_probe(void *data, async_cookie_t cookie)
2743 {
2744 	struct nvme_dev *dev = data;
2745 
2746 	flush_work(&dev->ctrl.reset_work);
2747 	flush_work(&dev->ctrl.scan_work);
2748 	nvme_put_ctrl(&dev->ctrl);
2749 }
2750 
2751 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
2752 {
2753 	int node, result = -ENOMEM;
2754 	struct nvme_dev *dev;
2755 	unsigned long quirks = id->driver_data;
2756 	size_t alloc_size;
2757 
2758 	node = dev_to_node(&pdev->dev);
2759 	if (node == NUMA_NO_NODE)
2760 		set_dev_node(&pdev->dev, first_memory_node);
2761 
2762 	dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
2763 	if (!dev)
2764 		return -ENOMEM;
2765 
2766 	dev->queues = kcalloc_node(max_queue_count(), sizeof(struct nvme_queue),
2767 					GFP_KERNEL, node);
2768 	if (!dev->queues)
2769 		goto free;
2770 
2771 	dev->dev = get_device(&pdev->dev);
2772 	pci_set_drvdata(pdev, dev);
2773 
2774 	result = nvme_dev_map(dev);
2775 	if (result)
2776 		goto put_pci;
2777 
2778 	INIT_WORK(&dev->ctrl.reset_work, nvme_reset_work);
2779 	INIT_WORK(&dev->remove_work, nvme_remove_dead_ctrl_work);
2780 	mutex_init(&dev->shutdown_lock);
2781 
2782 	result = nvme_setup_prp_pools(dev);
2783 	if (result)
2784 		goto unmap;
2785 
2786 	quirks |= check_vendor_combination_bug(pdev);
2787 
2788 	/*
2789 	 * Double check that our mempool alloc size will cover the biggest
2790 	 * command we support.
2791 	 */
2792 	alloc_size = nvme_pci_iod_alloc_size(dev, NVME_MAX_KB_SZ,
2793 						NVME_MAX_SEGS, true);
2794 	WARN_ON_ONCE(alloc_size > PAGE_SIZE);
2795 
2796 	dev->iod_mempool = mempool_create_node(1, mempool_kmalloc,
2797 						mempool_kfree,
2798 						(void *) alloc_size,
2799 						GFP_KERNEL, node);
2800 	if (!dev->iod_mempool) {
2801 		result = -ENOMEM;
2802 		goto release_pools;
2803 	}
2804 
2805 	result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
2806 			quirks);
2807 	if (result)
2808 		goto release_mempool;
2809 
2810 	dev_info(dev->ctrl.device, "pci function %s\n", dev_name(&pdev->dev));
2811 
2812 	nvme_reset_ctrl(&dev->ctrl);
2813 	nvme_get_ctrl(&dev->ctrl);
2814 	async_schedule(nvme_async_probe, dev);
2815 
2816 	return 0;
2817 
2818  release_mempool:
2819 	mempool_destroy(dev->iod_mempool);
2820  release_pools:
2821 	nvme_release_prp_pools(dev);
2822  unmap:
2823 	nvme_dev_unmap(dev);
2824  put_pci:
2825 	put_device(dev->dev);
2826  free:
2827 	kfree(dev->queues);
2828 	kfree(dev);
2829 	return result;
2830 }
2831 
2832 static void nvme_reset_prepare(struct pci_dev *pdev)
2833 {
2834 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2835 
2836 	/*
2837 	 * We don't need to check the return value from waiting for the reset
2838 	 * state as pci_dev device lock is held, making it impossible to race
2839 	 * with ->remove().
2840 	 */
2841 	nvme_disable_prepare_reset(dev, false);
2842 	nvme_sync_queues(&dev->ctrl);
2843 }
2844 
2845 static void nvme_reset_done(struct pci_dev *pdev)
2846 {
2847 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2848 
2849 	if (!nvme_try_sched_reset(&dev->ctrl))
2850 		flush_work(&dev->ctrl.reset_work);
2851 }
2852 
2853 static void nvme_shutdown(struct pci_dev *pdev)
2854 {
2855 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2856 	nvme_disable_prepare_reset(dev, true);
2857 }
2858 
2859 /*
2860  * The driver's remove may be called on a device in a partially initialized
2861  * state. This function must not have any dependencies on the device state in
2862  * order to proceed.
2863  */
2864 static void nvme_remove(struct pci_dev *pdev)
2865 {
2866 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2867 
2868 	nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING);
2869 	pci_set_drvdata(pdev, NULL);
2870 
2871 	if (!pci_device_is_present(pdev)) {
2872 		nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DEAD);
2873 		nvme_dev_disable(dev, true);
2874 		nvme_dev_remove_admin(dev);
2875 	}
2876 
2877 	flush_work(&dev->ctrl.reset_work);
2878 	nvme_stop_ctrl(&dev->ctrl);
2879 	nvme_remove_namespaces(&dev->ctrl);
2880 	nvme_dev_disable(dev, true);
2881 	nvme_release_cmb(dev);
2882 	nvme_free_host_mem(dev);
2883 	nvme_dev_remove_admin(dev);
2884 	nvme_free_queues(dev, 0);
2885 	nvme_uninit_ctrl(&dev->ctrl);
2886 	nvme_release_prp_pools(dev);
2887 	nvme_dev_unmap(dev);
2888 	nvme_put_ctrl(&dev->ctrl);
2889 }
2890 
2891 #ifdef CONFIG_PM_SLEEP
2892 static int nvme_get_power_state(struct nvme_ctrl *ctrl, u32 *ps)
2893 {
2894 	return nvme_get_features(ctrl, NVME_FEAT_POWER_MGMT, 0, NULL, 0, ps);
2895 }
2896 
2897 static int nvme_set_power_state(struct nvme_ctrl *ctrl, u32 ps)
2898 {
2899 	return nvme_set_features(ctrl, NVME_FEAT_POWER_MGMT, ps, NULL, 0, NULL);
2900 }
2901 
2902 static int nvme_resume(struct device *dev)
2903 {
2904 	struct nvme_dev *ndev = pci_get_drvdata(to_pci_dev(dev));
2905 	struct nvme_ctrl *ctrl = &ndev->ctrl;
2906 
2907 	if (ndev->last_ps == U32_MAX ||
2908 	    nvme_set_power_state(ctrl, ndev->last_ps) != 0)
2909 		return nvme_try_sched_reset(&ndev->ctrl);
2910 	return 0;
2911 }
2912 
2913 static int nvme_suspend(struct device *dev)
2914 {
2915 	struct pci_dev *pdev = to_pci_dev(dev);
2916 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2917 	struct nvme_ctrl *ctrl = &ndev->ctrl;
2918 	int ret = -EBUSY;
2919 
2920 	ndev->last_ps = U32_MAX;
2921 
2922 	/*
2923 	 * The platform does not remove power for a kernel managed suspend so
2924 	 * use host managed nvme power settings for lowest idle power if
2925 	 * possible. This should have quicker resume latency than a full device
2926 	 * shutdown.  But if the firmware is involved after the suspend or the
2927 	 * device does not support any non-default power states, shut down the
2928 	 * device fully.
2929 	 *
2930 	 * If ASPM is not enabled for the device, shut down the device and allow
2931 	 * the PCI bus layer to put it into D3 in order to take the PCIe link
2932 	 * down, so as to allow the platform to achieve its minimum low-power
2933 	 * state (which may not be possible if the link is up).
2934 	 */
2935 	if (pm_suspend_via_firmware() || !ctrl->npss ||
2936 	    !pcie_aspm_enabled(pdev) ||
2937 	    (ndev->ctrl.quirks & NVME_QUIRK_SIMPLE_SUSPEND))
2938 		return nvme_disable_prepare_reset(ndev, true);
2939 
2940 	nvme_start_freeze(ctrl);
2941 	nvme_wait_freeze(ctrl);
2942 	nvme_sync_queues(ctrl);
2943 
2944 	if (ctrl->state != NVME_CTRL_LIVE)
2945 		goto unfreeze;
2946 
2947 	ret = nvme_get_power_state(ctrl, &ndev->last_ps);
2948 	if (ret < 0)
2949 		goto unfreeze;
2950 
2951 	/*
2952 	 * A saved state prevents pci pm from generically controlling the
2953 	 * device's power. If we're using protocol specific settings, we don't
2954 	 * want pci interfering.
2955 	 */
2956 	pci_save_state(pdev);
2957 
2958 	ret = nvme_set_power_state(ctrl, ctrl->npss);
2959 	if (ret < 0)
2960 		goto unfreeze;
2961 
2962 	if (ret) {
2963 		/* discard the saved state */
2964 		pci_load_saved_state(pdev, NULL);
2965 
2966 		/*
2967 		 * Clearing npss forces a controller reset on resume. The
2968 		 * correct value will be rediscovered then.
2969 		 */
2970 		ret = nvme_disable_prepare_reset(ndev, true);
2971 		ctrl->npss = 0;
2972 	}
2973 unfreeze:
2974 	nvme_unfreeze(ctrl);
2975 	return ret;
2976 }
2977 
2978 static int nvme_simple_suspend(struct device *dev)
2979 {
2980 	struct nvme_dev *ndev = pci_get_drvdata(to_pci_dev(dev));
2981 	return nvme_disable_prepare_reset(ndev, true);
2982 }
2983 
2984 static int nvme_simple_resume(struct device *dev)
2985 {
2986 	struct pci_dev *pdev = to_pci_dev(dev);
2987 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2988 
2989 	return nvme_try_sched_reset(&ndev->ctrl);
2990 }
2991 
2992 static const struct dev_pm_ops nvme_dev_pm_ops = {
2993 	.suspend	= nvme_suspend,
2994 	.resume		= nvme_resume,
2995 	.freeze		= nvme_simple_suspend,
2996 	.thaw		= nvme_simple_resume,
2997 	.poweroff	= nvme_simple_suspend,
2998 	.restore	= nvme_simple_resume,
2999 };
3000 #endif /* CONFIG_PM_SLEEP */
3001 
3002 static pci_ers_result_t nvme_error_detected(struct pci_dev *pdev,
3003 						pci_channel_state_t state)
3004 {
3005 	struct nvme_dev *dev = pci_get_drvdata(pdev);
3006 
3007 	/*
3008 	 * A frozen channel requires a reset. When detected, this method will
3009 	 * shutdown the controller to quiesce. The controller will be restarted
3010 	 * after the slot reset through driver's slot_reset callback.
3011 	 */
3012 	switch (state) {
3013 	case pci_channel_io_normal:
3014 		return PCI_ERS_RESULT_CAN_RECOVER;
3015 	case pci_channel_io_frozen:
3016 		dev_warn(dev->ctrl.device,
3017 			"frozen state error detected, reset controller\n");
3018 		nvme_dev_disable(dev, false);
3019 		return PCI_ERS_RESULT_NEED_RESET;
3020 	case pci_channel_io_perm_failure:
3021 		dev_warn(dev->ctrl.device,
3022 			"failure state error detected, request disconnect\n");
3023 		return PCI_ERS_RESULT_DISCONNECT;
3024 	}
3025 	return PCI_ERS_RESULT_NEED_RESET;
3026 }
3027 
3028 static pci_ers_result_t nvme_slot_reset(struct pci_dev *pdev)
3029 {
3030 	struct nvme_dev *dev = pci_get_drvdata(pdev);
3031 
3032 	dev_info(dev->ctrl.device, "restart after slot reset\n");
3033 	pci_restore_state(pdev);
3034 	nvme_reset_ctrl(&dev->ctrl);
3035 	return PCI_ERS_RESULT_RECOVERED;
3036 }
3037 
3038 static void nvme_error_resume(struct pci_dev *pdev)
3039 {
3040 	struct nvme_dev *dev = pci_get_drvdata(pdev);
3041 
3042 	flush_work(&dev->ctrl.reset_work);
3043 }
3044 
3045 static const struct pci_error_handlers nvme_err_handler = {
3046 	.error_detected	= nvme_error_detected,
3047 	.slot_reset	= nvme_slot_reset,
3048 	.resume		= nvme_error_resume,
3049 	.reset_prepare	= nvme_reset_prepare,
3050 	.reset_done	= nvme_reset_done,
3051 };
3052 
3053 static const struct pci_device_id nvme_id_table[] = {
3054 	{ PCI_VDEVICE(INTEL, 0x0953),
3055 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
3056 				NVME_QUIRK_DEALLOCATE_ZEROES, },
3057 	{ PCI_VDEVICE(INTEL, 0x0a53),
3058 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
3059 				NVME_QUIRK_DEALLOCATE_ZEROES, },
3060 	{ PCI_VDEVICE(INTEL, 0x0a54),
3061 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
3062 				NVME_QUIRK_DEALLOCATE_ZEROES, },
3063 	{ PCI_VDEVICE(INTEL, 0x0a55),
3064 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
3065 				NVME_QUIRK_DEALLOCATE_ZEROES, },
3066 	{ PCI_VDEVICE(INTEL, 0xf1a5),	/* Intel 600P/P3100 */
3067 		.driver_data = NVME_QUIRK_NO_DEEPEST_PS |
3068 				NVME_QUIRK_MEDIUM_PRIO_SQ |
3069 				NVME_QUIRK_NO_TEMP_THRESH_CHANGE },
3070 	{ PCI_VDEVICE(INTEL, 0xf1a6),	/* Intel 760p/Pro 7600p */
3071 		.driver_data = NVME_QUIRK_IGNORE_DEV_SUBNQN, },
3072 	{ PCI_VDEVICE(INTEL, 0x5845),	/* Qemu emulated controller */
3073 		.driver_data = NVME_QUIRK_IDENTIFY_CNS |
3074 				NVME_QUIRK_DISABLE_WRITE_ZEROES, },
3075 	{ PCI_DEVICE(0x1bb1, 0x0100),   /* Seagate Nytro Flash Storage */
3076 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
3077 	{ PCI_DEVICE(0x1c58, 0x0003),	/* HGST adapter */
3078 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
3079 	{ PCI_DEVICE(0x1c58, 0x0023),	/* WDC SN200 adapter */
3080 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
3081 	{ PCI_DEVICE(0x1c5f, 0x0540),	/* Memblaze Pblaze4 adapter */
3082 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
3083 	{ PCI_DEVICE(0x144d, 0xa821),   /* Samsung PM1725 */
3084 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
3085 	{ PCI_DEVICE(0x144d, 0xa822),   /* Samsung PM1725a */
3086 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
3087 	{ PCI_DEVICE(0x1d1d, 0x1f1f),	/* LighNVM qemu device */
3088 		.driver_data = NVME_QUIRK_LIGHTNVM, },
3089 	{ PCI_DEVICE(0x1d1d, 0x2807),	/* CNEX WL */
3090 		.driver_data = NVME_QUIRK_LIGHTNVM, },
3091 	{ PCI_DEVICE(0x1d1d, 0x2601),	/* CNEX Granby */
3092 		.driver_data = NVME_QUIRK_LIGHTNVM, },
3093 	{ PCI_DEVICE(0x10ec, 0x5762),   /* ADATA SX6000LNP */
3094 		.driver_data = NVME_QUIRK_IGNORE_DEV_SUBNQN, },
3095 	{ PCI_DEVICE(0x1cc1, 0x8201),   /* ADATA SX8200PNP 512GB */
3096 		.driver_data = NVME_QUIRK_NO_DEEPEST_PS |
3097 				NVME_QUIRK_IGNORE_DEV_SUBNQN, },
3098 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
3099 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
3100 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2003) },
3101 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2005),
3102 		.driver_data = NVME_QUIRK_SINGLE_VECTOR |
3103 				NVME_QUIRK_128_BYTES_SQES |
3104 				NVME_QUIRK_SHARED_TAGS },
3105 	{ 0, }
3106 };
3107 MODULE_DEVICE_TABLE(pci, nvme_id_table);
3108 
3109 static struct pci_driver nvme_driver = {
3110 	.name		= "nvme",
3111 	.id_table	= nvme_id_table,
3112 	.probe		= nvme_probe,
3113 	.remove		= nvme_remove,
3114 	.shutdown	= nvme_shutdown,
3115 #ifdef CONFIG_PM_SLEEP
3116 	.driver		= {
3117 		.pm	= &nvme_dev_pm_ops,
3118 	},
3119 #endif
3120 	.sriov_configure = pci_sriov_configure_simple,
3121 	.err_handler	= &nvme_err_handler,
3122 };
3123 
3124 static int __init nvme_init(void)
3125 {
3126 	BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
3127 	BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
3128 	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
3129 	BUILD_BUG_ON(IRQ_AFFINITY_MAX_SETS < 2);
3130 
3131 	write_queues = min(write_queues, num_possible_cpus());
3132 	poll_queues = min(poll_queues, num_possible_cpus());
3133 	return pci_register_driver(&nvme_driver);
3134 }
3135 
3136 static void __exit nvme_exit(void)
3137 {
3138 	pci_unregister_driver(&nvme_driver);
3139 	flush_workqueue(nvme_wq);
3140 }
3141 
3142 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
3143 MODULE_LICENSE("GPL");
3144 MODULE_VERSION("1.0");
3145 module_init(nvme_init);
3146 module_exit(nvme_exit);
3147