xref: /linux/drivers/nvme/host/pci.c (revision e21f9e2e862e9eb3dd64eaddb6256b3e5098660f)
1 /*
2  * NVM Express device driver
3  * Copyright (c) 2011-2014, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  */
14 
15 #include <linux/aer.h>
16 #include <linux/blkdev.h>
17 #include <linux/blk-mq.h>
18 #include <linux/blk-mq-pci.h>
19 #include <linux/dmi.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/mm.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/once.h>
27 #include <linux/pci.h>
28 #include <linux/t10-pi.h>
29 #include <linux/types.h>
30 #include <linux/io-64-nonatomic-lo-hi.h>
31 #include <linux/sed-opal.h>
32 
33 #include "nvme.h"
34 
35 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
36 #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
37 
38 #define SGES_PER_PAGE	(PAGE_SIZE / sizeof(struct nvme_sgl_desc))
39 
40 static int use_threaded_interrupts;
41 module_param(use_threaded_interrupts, int, 0);
42 
43 static bool use_cmb_sqes = true;
44 module_param(use_cmb_sqes, bool, 0644);
45 MODULE_PARM_DESC(use_cmb_sqes, "use controller's memory buffer for I/O SQes");
46 
47 static unsigned int max_host_mem_size_mb = 128;
48 module_param(max_host_mem_size_mb, uint, 0444);
49 MODULE_PARM_DESC(max_host_mem_size_mb,
50 	"Maximum Host Memory Buffer (HMB) size per controller (in MiB)");
51 
52 static unsigned int sgl_threshold = SZ_32K;
53 module_param(sgl_threshold, uint, 0644);
54 MODULE_PARM_DESC(sgl_threshold,
55 		"Use SGLs when average request segment size is larger or equal to "
56 		"this size. Use 0 to disable SGLs.");
57 
58 static int io_queue_depth_set(const char *val, const struct kernel_param *kp);
59 static const struct kernel_param_ops io_queue_depth_ops = {
60 	.set = io_queue_depth_set,
61 	.get = param_get_int,
62 };
63 
64 static int io_queue_depth = 1024;
65 module_param_cb(io_queue_depth, &io_queue_depth_ops, &io_queue_depth, 0644);
66 MODULE_PARM_DESC(io_queue_depth, "set io queue depth, should >= 2");
67 
68 struct nvme_dev;
69 struct nvme_queue;
70 
71 static void nvme_process_cq(struct nvme_queue *nvmeq);
72 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
73 
74 /*
75  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
76  */
77 struct nvme_dev {
78 	struct nvme_queue *queues;
79 	struct blk_mq_tag_set tagset;
80 	struct blk_mq_tag_set admin_tagset;
81 	u32 __iomem *dbs;
82 	struct device *dev;
83 	struct dma_pool *prp_page_pool;
84 	struct dma_pool *prp_small_pool;
85 	unsigned online_queues;
86 	unsigned max_qid;
87 	unsigned int num_vecs;
88 	int q_depth;
89 	u32 db_stride;
90 	void __iomem *bar;
91 	unsigned long bar_mapped_size;
92 	struct work_struct remove_work;
93 	struct mutex shutdown_lock;
94 	bool subsystem;
95 	void __iomem *cmb;
96 	pci_bus_addr_t cmb_bus_addr;
97 	u64 cmb_size;
98 	u32 cmbsz;
99 	u32 cmbloc;
100 	struct nvme_ctrl ctrl;
101 	struct completion ioq_wait;
102 
103 	/* shadow doorbell buffer support: */
104 	u32 *dbbuf_dbs;
105 	dma_addr_t dbbuf_dbs_dma_addr;
106 	u32 *dbbuf_eis;
107 	dma_addr_t dbbuf_eis_dma_addr;
108 
109 	/* host memory buffer support: */
110 	u64 host_mem_size;
111 	u32 nr_host_mem_descs;
112 	dma_addr_t host_mem_descs_dma;
113 	struct nvme_host_mem_buf_desc *host_mem_descs;
114 	void **host_mem_desc_bufs;
115 };
116 
117 static int io_queue_depth_set(const char *val, const struct kernel_param *kp)
118 {
119 	int n = 0, ret;
120 
121 	ret = kstrtoint(val, 10, &n);
122 	if (ret != 0 || n < 2)
123 		return -EINVAL;
124 
125 	return param_set_int(val, kp);
126 }
127 
128 static inline unsigned int sq_idx(unsigned int qid, u32 stride)
129 {
130 	return qid * 2 * stride;
131 }
132 
133 static inline unsigned int cq_idx(unsigned int qid, u32 stride)
134 {
135 	return (qid * 2 + 1) * stride;
136 }
137 
138 static inline struct nvme_dev *to_nvme_dev(struct nvme_ctrl *ctrl)
139 {
140 	return container_of(ctrl, struct nvme_dev, ctrl);
141 }
142 
143 /*
144  * An NVM Express queue.  Each device has at least two (one for admin
145  * commands and one for I/O commands).
146  */
147 struct nvme_queue {
148 	struct device *q_dmadev;
149 	struct nvme_dev *dev;
150 	spinlock_t q_lock;
151 	struct nvme_command *sq_cmds;
152 	struct nvme_command __iomem *sq_cmds_io;
153 	volatile struct nvme_completion *cqes;
154 	struct blk_mq_tags **tags;
155 	dma_addr_t sq_dma_addr;
156 	dma_addr_t cq_dma_addr;
157 	u32 __iomem *q_db;
158 	u16 q_depth;
159 	s16 cq_vector;
160 	u16 sq_tail;
161 	u16 cq_head;
162 	u16 qid;
163 	u8 cq_phase;
164 	u8 cqe_seen;
165 	u32 *dbbuf_sq_db;
166 	u32 *dbbuf_cq_db;
167 	u32 *dbbuf_sq_ei;
168 	u32 *dbbuf_cq_ei;
169 };
170 
171 /*
172  * The nvme_iod describes the data in an I/O, including the list of PRP
173  * entries.  You can't see it in this data structure because C doesn't let
174  * me express that.  Use nvme_init_iod to ensure there's enough space
175  * allocated to store the PRP list.
176  */
177 struct nvme_iod {
178 	struct nvme_request req;
179 	struct nvme_queue *nvmeq;
180 	bool use_sgl;
181 	int aborted;
182 	int npages;		/* In the PRP list. 0 means small pool in use */
183 	int nents;		/* Used in scatterlist */
184 	int length;		/* Of data, in bytes */
185 	dma_addr_t first_dma;
186 	struct scatterlist meta_sg; /* metadata requires single contiguous buffer */
187 	struct scatterlist *sg;
188 	struct scatterlist inline_sg[0];
189 };
190 
191 /*
192  * Check we didin't inadvertently grow the command struct
193  */
194 static inline void _nvme_check_size(void)
195 {
196 	BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
197 	BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
198 	BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
199 	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
200 	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
201 	BUILD_BUG_ON(sizeof(struct nvme_format_cmd) != 64);
202 	BUILD_BUG_ON(sizeof(struct nvme_abort_cmd) != 64);
203 	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
204 	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != NVME_IDENTIFY_DATA_SIZE);
205 	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != NVME_IDENTIFY_DATA_SIZE);
206 	BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
207 	BUILD_BUG_ON(sizeof(struct nvme_smart_log) != 512);
208 	BUILD_BUG_ON(sizeof(struct nvme_dbbuf) != 64);
209 }
210 
211 static inline unsigned int nvme_dbbuf_size(u32 stride)
212 {
213 	return ((num_possible_cpus() + 1) * 8 * stride);
214 }
215 
216 static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
217 {
218 	unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
219 
220 	if (dev->dbbuf_dbs)
221 		return 0;
222 
223 	dev->dbbuf_dbs = dma_alloc_coherent(dev->dev, mem_size,
224 					    &dev->dbbuf_dbs_dma_addr,
225 					    GFP_KERNEL);
226 	if (!dev->dbbuf_dbs)
227 		return -ENOMEM;
228 	dev->dbbuf_eis = dma_alloc_coherent(dev->dev, mem_size,
229 					    &dev->dbbuf_eis_dma_addr,
230 					    GFP_KERNEL);
231 	if (!dev->dbbuf_eis) {
232 		dma_free_coherent(dev->dev, mem_size,
233 				  dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
234 		dev->dbbuf_dbs = NULL;
235 		return -ENOMEM;
236 	}
237 
238 	return 0;
239 }
240 
241 static void nvme_dbbuf_dma_free(struct nvme_dev *dev)
242 {
243 	unsigned int mem_size = nvme_dbbuf_size(dev->db_stride);
244 
245 	if (dev->dbbuf_dbs) {
246 		dma_free_coherent(dev->dev, mem_size,
247 				  dev->dbbuf_dbs, dev->dbbuf_dbs_dma_addr);
248 		dev->dbbuf_dbs = NULL;
249 	}
250 	if (dev->dbbuf_eis) {
251 		dma_free_coherent(dev->dev, mem_size,
252 				  dev->dbbuf_eis, dev->dbbuf_eis_dma_addr);
253 		dev->dbbuf_eis = NULL;
254 	}
255 }
256 
257 static void nvme_dbbuf_init(struct nvme_dev *dev,
258 			    struct nvme_queue *nvmeq, int qid)
259 {
260 	if (!dev->dbbuf_dbs || !qid)
261 		return;
262 
263 	nvmeq->dbbuf_sq_db = &dev->dbbuf_dbs[sq_idx(qid, dev->db_stride)];
264 	nvmeq->dbbuf_cq_db = &dev->dbbuf_dbs[cq_idx(qid, dev->db_stride)];
265 	nvmeq->dbbuf_sq_ei = &dev->dbbuf_eis[sq_idx(qid, dev->db_stride)];
266 	nvmeq->dbbuf_cq_ei = &dev->dbbuf_eis[cq_idx(qid, dev->db_stride)];
267 }
268 
269 static void nvme_dbbuf_set(struct nvme_dev *dev)
270 {
271 	struct nvme_command c;
272 
273 	if (!dev->dbbuf_dbs)
274 		return;
275 
276 	memset(&c, 0, sizeof(c));
277 	c.dbbuf.opcode = nvme_admin_dbbuf;
278 	c.dbbuf.prp1 = cpu_to_le64(dev->dbbuf_dbs_dma_addr);
279 	c.dbbuf.prp2 = cpu_to_le64(dev->dbbuf_eis_dma_addr);
280 
281 	if (nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0)) {
282 		dev_warn(dev->ctrl.device, "unable to set dbbuf\n");
283 		/* Free memory and continue on */
284 		nvme_dbbuf_dma_free(dev);
285 	}
286 }
287 
288 static inline int nvme_dbbuf_need_event(u16 event_idx, u16 new_idx, u16 old)
289 {
290 	return (u16)(new_idx - event_idx - 1) < (u16)(new_idx - old);
291 }
292 
293 /* Update dbbuf and return true if an MMIO is required */
294 static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db,
295 					      volatile u32 *dbbuf_ei)
296 {
297 	if (dbbuf_db) {
298 		u16 old_value;
299 
300 		/*
301 		 * Ensure that the queue is written before updating
302 		 * the doorbell in memory
303 		 */
304 		wmb();
305 
306 		old_value = *dbbuf_db;
307 		*dbbuf_db = value;
308 
309 		if (!nvme_dbbuf_need_event(*dbbuf_ei, value, old_value))
310 			return false;
311 	}
312 
313 	return true;
314 }
315 
316 /*
317  * Max size of iod being embedded in the request payload
318  */
319 #define NVME_INT_PAGES		2
320 #define NVME_INT_BYTES(dev)	(NVME_INT_PAGES * (dev)->ctrl.page_size)
321 
322 /*
323  * Will slightly overestimate the number of pages needed.  This is OK
324  * as it only leads to a small amount of wasted memory for the lifetime of
325  * the I/O.
326  */
327 static int nvme_npages(unsigned size, struct nvme_dev *dev)
328 {
329 	unsigned nprps = DIV_ROUND_UP(size + dev->ctrl.page_size,
330 				      dev->ctrl.page_size);
331 	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
332 }
333 
334 /*
335  * Calculates the number of pages needed for the SGL segments. For example a 4k
336  * page can accommodate 256 SGL descriptors.
337  */
338 static int nvme_pci_npages_sgl(unsigned int num_seg)
339 {
340 	return DIV_ROUND_UP(num_seg * sizeof(struct nvme_sgl_desc), PAGE_SIZE);
341 }
342 
343 static unsigned int nvme_pci_iod_alloc_size(struct nvme_dev *dev,
344 		unsigned int size, unsigned int nseg, bool use_sgl)
345 {
346 	size_t alloc_size;
347 
348 	if (use_sgl)
349 		alloc_size = sizeof(__le64 *) * nvme_pci_npages_sgl(nseg);
350 	else
351 		alloc_size = sizeof(__le64 *) * nvme_npages(size, dev);
352 
353 	return alloc_size + sizeof(struct scatterlist) * nseg;
354 }
355 
356 static unsigned int nvme_pci_cmd_size(struct nvme_dev *dev, bool use_sgl)
357 {
358 	unsigned int alloc_size = nvme_pci_iod_alloc_size(dev,
359 				    NVME_INT_BYTES(dev), NVME_INT_PAGES,
360 				    use_sgl);
361 
362 	return sizeof(struct nvme_iod) + alloc_size;
363 }
364 
365 static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
366 				unsigned int hctx_idx)
367 {
368 	struct nvme_dev *dev = data;
369 	struct nvme_queue *nvmeq = &dev->queues[0];
370 
371 	WARN_ON(hctx_idx != 0);
372 	WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);
373 	WARN_ON(nvmeq->tags);
374 
375 	hctx->driver_data = nvmeq;
376 	nvmeq->tags = &dev->admin_tagset.tags[0];
377 	return 0;
378 }
379 
380 static void nvme_admin_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
381 {
382 	struct nvme_queue *nvmeq = hctx->driver_data;
383 
384 	nvmeq->tags = NULL;
385 }
386 
387 static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
388 			  unsigned int hctx_idx)
389 {
390 	struct nvme_dev *dev = data;
391 	struct nvme_queue *nvmeq = &dev->queues[hctx_idx + 1];
392 
393 	if (!nvmeq->tags)
394 		nvmeq->tags = &dev->tagset.tags[hctx_idx];
395 
396 	WARN_ON(dev->tagset.tags[hctx_idx] != hctx->tags);
397 	hctx->driver_data = nvmeq;
398 	return 0;
399 }
400 
401 static int nvme_init_request(struct blk_mq_tag_set *set, struct request *req,
402 		unsigned int hctx_idx, unsigned int numa_node)
403 {
404 	struct nvme_dev *dev = set->driver_data;
405 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
406 	int queue_idx = (set == &dev->tagset) ? hctx_idx + 1 : 0;
407 	struct nvme_queue *nvmeq = &dev->queues[queue_idx];
408 
409 	BUG_ON(!nvmeq);
410 	iod->nvmeq = nvmeq;
411 	return 0;
412 }
413 
414 static int nvme_pci_map_queues(struct blk_mq_tag_set *set)
415 {
416 	struct nvme_dev *dev = set->driver_data;
417 
418 	return blk_mq_pci_map_queues(set, to_pci_dev(dev->dev),
419 			dev->num_vecs > 1 ? 1 /* admin queue */ : 0);
420 }
421 
422 /**
423  * __nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
424  * @nvmeq: The queue to use
425  * @cmd: The command to send
426  *
427  * Safe to use from interrupt context
428  */
429 static void __nvme_submit_cmd(struct nvme_queue *nvmeq,
430 						struct nvme_command *cmd)
431 {
432 	u16 tail = nvmeq->sq_tail;
433 
434 	if (nvmeq->sq_cmds_io)
435 		memcpy_toio(&nvmeq->sq_cmds_io[tail], cmd, sizeof(*cmd));
436 	else
437 		memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
438 
439 	if (++tail == nvmeq->q_depth)
440 		tail = 0;
441 	if (nvme_dbbuf_update_and_check_event(tail, nvmeq->dbbuf_sq_db,
442 					      nvmeq->dbbuf_sq_ei))
443 		writel(tail, nvmeq->q_db);
444 	nvmeq->sq_tail = tail;
445 }
446 
447 static void **nvme_pci_iod_list(struct request *req)
448 {
449 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
450 	return (void **)(iod->sg + blk_rq_nr_phys_segments(req));
451 }
452 
453 static inline bool nvme_pci_use_sgls(struct nvme_dev *dev, struct request *req)
454 {
455 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
456 	int nseg = blk_rq_nr_phys_segments(req);
457 	unsigned int avg_seg_size;
458 
459 	if (nseg == 0)
460 		return false;
461 
462 	avg_seg_size = DIV_ROUND_UP(blk_rq_payload_bytes(req), nseg);
463 
464 	if (!(dev->ctrl.sgls & ((1 << 0) | (1 << 1))))
465 		return false;
466 	if (!iod->nvmeq->qid)
467 		return false;
468 	if (!sgl_threshold || avg_seg_size < sgl_threshold)
469 		return false;
470 	return true;
471 }
472 
473 static blk_status_t nvme_init_iod(struct request *rq, struct nvme_dev *dev)
474 {
475 	struct nvme_iod *iod = blk_mq_rq_to_pdu(rq);
476 	int nseg = blk_rq_nr_phys_segments(rq);
477 	unsigned int size = blk_rq_payload_bytes(rq);
478 
479 	iod->use_sgl = nvme_pci_use_sgls(dev, rq);
480 
481 	if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
482 		size_t alloc_size = nvme_pci_iod_alloc_size(dev, size, nseg,
483 				iod->use_sgl);
484 
485 		iod->sg = kmalloc(alloc_size, GFP_ATOMIC);
486 		if (!iod->sg)
487 			return BLK_STS_RESOURCE;
488 	} else {
489 		iod->sg = iod->inline_sg;
490 	}
491 
492 	iod->aborted = 0;
493 	iod->npages = -1;
494 	iod->nents = 0;
495 	iod->length = size;
496 
497 	return BLK_STS_OK;
498 }
499 
500 static void nvme_free_iod(struct nvme_dev *dev, struct request *req)
501 {
502 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
503 	const int last_prp = dev->ctrl.page_size / sizeof(__le64) - 1;
504 	dma_addr_t dma_addr = iod->first_dma, next_dma_addr;
505 
506 	int i;
507 
508 	if (iod->npages == 0)
509 		dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0],
510 			dma_addr);
511 
512 	for (i = 0; i < iod->npages; i++) {
513 		void *addr = nvme_pci_iod_list(req)[i];
514 
515 		if (iod->use_sgl) {
516 			struct nvme_sgl_desc *sg_list = addr;
517 
518 			next_dma_addr =
519 			    le64_to_cpu((sg_list[SGES_PER_PAGE - 1]).addr);
520 		} else {
521 			__le64 *prp_list = addr;
522 
523 			next_dma_addr = le64_to_cpu(prp_list[last_prp]);
524 		}
525 
526 		dma_pool_free(dev->prp_page_pool, addr, dma_addr);
527 		dma_addr = next_dma_addr;
528 	}
529 
530 	if (iod->sg != iod->inline_sg)
531 		kfree(iod->sg);
532 }
533 
534 #ifdef CONFIG_BLK_DEV_INTEGRITY
535 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
536 {
537 	if (be32_to_cpu(pi->ref_tag) == v)
538 		pi->ref_tag = cpu_to_be32(p);
539 }
540 
541 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
542 {
543 	if (be32_to_cpu(pi->ref_tag) == p)
544 		pi->ref_tag = cpu_to_be32(v);
545 }
546 
547 /**
548  * nvme_dif_remap - remaps ref tags to bip seed and physical lba
549  *
550  * The virtual start sector is the one that was originally submitted by the
551  * block layer.	Due to partitioning, MD/DM cloning, etc. the actual physical
552  * start sector may be different. Remap protection information to match the
553  * physical LBA on writes, and back to the original seed on reads.
554  *
555  * Type 0 and 3 do not have a ref tag, so no remapping required.
556  */
557 static void nvme_dif_remap(struct request *req,
558 			void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
559 {
560 	struct nvme_ns *ns = req->rq_disk->private_data;
561 	struct bio_integrity_payload *bip;
562 	struct t10_pi_tuple *pi;
563 	void *p, *pmap;
564 	u32 i, nlb, ts, phys, virt;
565 
566 	if (!ns->pi_type || ns->pi_type == NVME_NS_DPS_PI_TYPE3)
567 		return;
568 
569 	bip = bio_integrity(req->bio);
570 	if (!bip)
571 		return;
572 
573 	pmap = kmap_atomic(bip->bip_vec->bv_page) + bip->bip_vec->bv_offset;
574 
575 	p = pmap;
576 	virt = bip_get_seed(bip);
577 	phys = nvme_block_nr(ns, blk_rq_pos(req));
578 	nlb = (blk_rq_bytes(req) >> ns->lba_shift);
579 	ts = ns->disk->queue->integrity.tuple_size;
580 
581 	for (i = 0; i < nlb; i++, virt++, phys++) {
582 		pi = (struct t10_pi_tuple *)p;
583 		dif_swap(phys, virt, pi);
584 		p += ts;
585 	}
586 	kunmap_atomic(pmap);
587 }
588 #else /* CONFIG_BLK_DEV_INTEGRITY */
589 static void nvme_dif_remap(struct request *req,
590 			void (*dif_swap)(u32 p, u32 v, struct t10_pi_tuple *pi))
591 {
592 }
593 static void nvme_dif_prep(u32 p, u32 v, struct t10_pi_tuple *pi)
594 {
595 }
596 static void nvme_dif_complete(u32 p, u32 v, struct t10_pi_tuple *pi)
597 {
598 }
599 #endif
600 
601 static void nvme_print_sgl(struct scatterlist *sgl, int nents)
602 {
603 	int i;
604 	struct scatterlist *sg;
605 
606 	for_each_sg(sgl, sg, nents, i) {
607 		dma_addr_t phys = sg_phys(sg);
608 		pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d "
609 			"dma_address:%pad dma_length:%d\n",
610 			i, &phys, sg->offset, sg->length, &sg_dma_address(sg),
611 			sg_dma_len(sg));
612 	}
613 }
614 
615 static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev,
616 		struct request *req, struct nvme_rw_command *cmnd)
617 {
618 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
619 	struct dma_pool *pool;
620 	int length = blk_rq_payload_bytes(req);
621 	struct scatterlist *sg = iod->sg;
622 	int dma_len = sg_dma_len(sg);
623 	u64 dma_addr = sg_dma_address(sg);
624 	u32 page_size = dev->ctrl.page_size;
625 	int offset = dma_addr & (page_size - 1);
626 	__le64 *prp_list;
627 	void **list = nvme_pci_iod_list(req);
628 	dma_addr_t prp_dma;
629 	int nprps, i;
630 
631 	length -= (page_size - offset);
632 	if (length <= 0) {
633 		iod->first_dma = 0;
634 		goto done;
635 	}
636 
637 	dma_len -= (page_size - offset);
638 	if (dma_len) {
639 		dma_addr += (page_size - offset);
640 	} else {
641 		sg = sg_next(sg);
642 		dma_addr = sg_dma_address(sg);
643 		dma_len = sg_dma_len(sg);
644 	}
645 
646 	if (length <= page_size) {
647 		iod->first_dma = dma_addr;
648 		goto done;
649 	}
650 
651 	nprps = DIV_ROUND_UP(length, page_size);
652 	if (nprps <= (256 / 8)) {
653 		pool = dev->prp_small_pool;
654 		iod->npages = 0;
655 	} else {
656 		pool = dev->prp_page_pool;
657 		iod->npages = 1;
658 	}
659 
660 	prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
661 	if (!prp_list) {
662 		iod->first_dma = dma_addr;
663 		iod->npages = -1;
664 		return BLK_STS_RESOURCE;
665 	}
666 	list[0] = prp_list;
667 	iod->first_dma = prp_dma;
668 	i = 0;
669 	for (;;) {
670 		if (i == page_size >> 3) {
671 			__le64 *old_prp_list = prp_list;
672 			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
673 			if (!prp_list)
674 				return BLK_STS_RESOURCE;
675 			list[iod->npages++] = prp_list;
676 			prp_list[0] = old_prp_list[i - 1];
677 			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
678 			i = 1;
679 		}
680 		prp_list[i++] = cpu_to_le64(dma_addr);
681 		dma_len -= page_size;
682 		dma_addr += page_size;
683 		length -= page_size;
684 		if (length <= 0)
685 			break;
686 		if (dma_len > 0)
687 			continue;
688 		if (unlikely(dma_len < 0))
689 			goto bad_sgl;
690 		sg = sg_next(sg);
691 		dma_addr = sg_dma_address(sg);
692 		dma_len = sg_dma_len(sg);
693 	}
694 
695 done:
696 	cmnd->dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
697 	cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma);
698 
699 	return BLK_STS_OK;
700 
701  bad_sgl:
702 	WARN(DO_ONCE(nvme_print_sgl, iod->sg, iod->nents),
703 			"Invalid SGL for payload:%d nents:%d\n",
704 			blk_rq_payload_bytes(req), iod->nents);
705 	return BLK_STS_IOERR;
706 }
707 
708 static void nvme_pci_sgl_set_data(struct nvme_sgl_desc *sge,
709 		struct scatterlist *sg)
710 {
711 	sge->addr = cpu_to_le64(sg_dma_address(sg));
712 	sge->length = cpu_to_le32(sg_dma_len(sg));
713 	sge->type = NVME_SGL_FMT_DATA_DESC << 4;
714 }
715 
716 static void nvme_pci_sgl_set_seg(struct nvme_sgl_desc *sge,
717 		dma_addr_t dma_addr, int entries)
718 {
719 	sge->addr = cpu_to_le64(dma_addr);
720 	if (entries < SGES_PER_PAGE) {
721 		sge->length = cpu_to_le32(entries * sizeof(*sge));
722 		sge->type = NVME_SGL_FMT_LAST_SEG_DESC << 4;
723 	} else {
724 		sge->length = cpu_to_le32(PAGE_SIZE);
725 		sge->type = NVME_SGL_FMT_SEG_DESC << 4;
726 	}
727 }
728 
729 static blk_status_t nvme_pci_setup_sgls(struct nvme_dev *dev,
730 		struct request *req, struct nvme_rw_command *cmd, int entries)
731 {
732 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
733 	struct dma_pool *pool;
734 	struct nvme_sgl_desc *sg_list;
735 	struct scatterlist *sg = iod->sg;
736 	dma_addr_t sgl_dma;
737 	int i = 0;
738 
739 	/* setting the transfer type as SGL */
740 	cmd->flags = NVME_CMD_SGL_METABUF;
741 
742 	if (entries == 1) {
743 		nvme_pci_sgl_set_data(&cmd->dptr.sgl, sg);
744 		return BLK_STS_OK;
745 	}
746 
747 	if (entries <= (256 / sizeof(struct nvme_sgl_desc))) {
748 		pool = dev->prp_small_pool;
749 		iod->npages = 0;
750 	} else {
751 		pool = dev->prp_page_pool;
752 		iod->npages = 1;
753 	}
754 
755 	sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
756 	if (!sg_list) {
757 		iod->npages = -1;
758 		return BLK_STS_RESOURCE;
759 	}
760 
761 	nvme_pci_iod_list(req)[0] = sg_list;
762 	iod->first_dma = sgl_dma;
763 
764 	nvme_pci_sgl_set_seg(&cmd->dptr.sgl, sgl_dma, entries);
765 
766 	do {
767 		if (i == SGES_PER_PAGE) {
768 			struct nvme_sgl_desc *old_sg_desc = sg_list;
769 			struct nvme_sgl_desc *link = &old_sg_desc[i - 1];
770 
771 			sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
772 			if (!sg_list)
773 				return BLK_STS_RESOURCE;
774 
775 			i = 0;
776 			nvme_pci_iod_list(req)[iod->npages++] = sg_list;
777 			sg_list[i++] = *link;
778 			nvme_pci_sgl_set_seg(link, sgl_dma, entries);
779 		}
780 
781 		nvme_pci_sgl_set_data(&sg_list[i++], sg);
782 		sg = sg_next(sg);
783 	} while (--entries > 0);
784 
785 	return BLK_STS_OK;
786 }
787 
788 static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req,
789 		struct nvme_command *cmnd)
790 {
791 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
792 	struct request_queue *q = req->q;
793 	enum dma_data_direction dma_dir = rq_data_dir(req) ?
794 			DMA_TO_DEVICE : DMA_FROM_DEVICE;
795 	blk_status_t ret = BLK_STS_IOERR;
796 	int nr_mapped;
797 
798 	sg_init_table(iod->sg, blk_rq_nr_phys_segments(req));
799 	iod->nents = blk_rq_map_sg(q, req, iod->sg);
800 	if (!iod->nents)
801 		goto out;
802 
803 	ret = BLK_STS_RESOURCE;
804 	nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents, dma_dir,
805 			DMA_ATTR_NO_WARN);
806 	if (!nr_mapped)
807 		goto out;
808 
809 	if (iod->use_sgl)
810 		ret = nvme_pci_setup_sgls(dev, req, &cmnd->rw, nr_mapped);
811 	else
812 		ret = nvme_pci_setup_prps(dev, req, &cmnd->rw);
813 
814 	if (ret != BLK_STS_OK)
815 		goto out_unmap;
816 
817 	ret = BLK_STS_IOERR;
818 	if (blk_integrity_rq(req)) {
819 		if (blk_rq_count_integrity_sg(q, req->bio) != 1)
820 			goto out_unmap;
821 
822 		sg_init_table(&iod->meta_sg, 1);
823 		if (blk_rq_map_integrity_sg(q, req->bio, &iod->meta_sg) != 1)
824 			goto out_unmap;
825 
826 		if (req_op(req) == REQ_OP_WRITE)
827 			nvme_dif_remap(req, nvme_dif_prep);
828 
829 		if (!dma_map_sg(dev->dev, &iod->meta_sg, 1, dma_dir))
830 			goto out_unmap;
831 	}
832 
833 	if (blk_integrity_rq(req))
834 		cmnd->rw.metadata = cpu_to_le64(sg_dma_address(&iod->meta_sg));
835 	return BLK_STS_OK;
836 
837 out_unmap:
838 	dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
839 out:
840 	return ret;
841 }
842 
843 static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
844 {
845 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
846 	enum dma_data_direction dma_dir = rq_data_dir(req) ?
847 			DMA_TO_DEVICE : DMA_FROM_DEVICE;
848 
849 	if (iod->nents) {
850 		dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);
851 		if (blk_integrity_rq(req)) {
852 			if (req_op(req) == REQ_OP_READ)
853 				nvme_dif_remap(req, nvme_dif_complete);
854 			dma_unmap_sg(dev->dev, &iod->meta_sg, 1, dma_dir);
855 		}
856 	}
857 
858 	nvme_cleanup_cmd(req);
859 	nvme_free_iod(dev, req);
860 }
861 
862 /*
863  * NOTE: ns is NULL when called on the admin queue.
864  */
865 static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
866 			 const struct blk_mq_queue_data *bd)
867 {
868 	struct nvme_ns *ns = hctx->queue->queuedata;
869 	struct nvme_queue *nvmeq = hctx->driver_data;
870 	struct nvme_dev *dev = nvmeq->dev;
871 	struct request *req = bd->rq;
872 	struct nvme_command cmnd;
873 	blk_status_t ret;
874 
875 	ret = nvme_setup_cmd(ns, req, &cmnd);
876 	if (ret)
877 		return ret;
878 
879 	ret = nvme_init_iod(req, dev);
880 	if (ret)
881 		goto out_free_cmd;
882 
883 	if (blk_rq_nr_phys_segments(req)) {
884 		ret = nvme_map_data(dev, req, &cmnd);
885 		if (ret)
886 			goto out_cleanup_iod;
887 	}
888 
889 	blk_mq_start_request(req);
890 
891 	spin_lock_irq(&nvmeq->q_lock);
892 	if (unlikely(nvmeq->cq_vector < 0)) {
893 		ret = BLK_STS_IOERR;
894 		spin_unlock_irq(&nvmeq->q_lock);
895 		goto out_cleanup_iod;
896 	}
897 	__nvme_submit_cmd(nvmeq, &cmnd);
898 	nvme_process_cq(nvmeq);
899 	spin_unlock_irq(&nvmeq->q_lock);
900 	return BLK_STS_OK;
901 out_cleanup_iod:
902 	nvme_free_iod(dev, req);
903 out_free_cmd:
904 	nvme_cleanup_cmd(req);
905 	return ret;
906 }
907 
908 static void nvme_pci_complete_rq(struct request *req)
909 {
910 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
911 
912 	nvme_unmap_data(iod->nvmeq->dev, req);
913 	nvme_complete_rq(req);
914 }
915 
916 /* We read the CQE phase first to check if the rest of the entry is valid */
917 static inline bool nvme_cqe_valid(struct nvme_queue *nvmeq, u16 head,
918 		u16 phase)
919 {
920 	return (le16_to_cpu(nvmeq->cqes[head].status) & 1) == phase;
921 }
922 
923 static inline void nvme_ring_cq_doorbell(struct nvme_queue *nvmeq)
924 {
925 	u16 head = nvmeq->cq_head;
926 
927 	if (likely(nvmeq->cq_vector >= 0)) {
928 		if (nvme_dbbuf_update_and_check_event(head, nvmeq->dbbuf_cq_db,
929 						      nvmeq->dbbuf_cq_ei))
930 			writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
931 	}
932 }
933 
934 static inline void nvme_handle_cqe(struct nvme_queue *nvmeq,
935 		struct nvme_completion *cqe)
936 {
937 	struct request *req;
938 
939 	if (unlikely(cqe->command_id >= nvmeq->q_depth)) {
940 		dev_warn(nvmeq->dev->ctrl.device,
941 			"invalid id %d completed on queue %d\n",
942 			cqe->command_id, le16_to_cpu(cqe->sq_id));
943 		return;
944 	}
945 
946 	/*
947 	 * AEN requests are special as they don't time out and can
948 	 * survive any kind of queue freeze and often don't respond to
949 	 * aborts.  We don't even bother to allocate a struct request
950 	 * for them but rather special case them here.
951 	 */
952 	if (unlikely(nvmeq->qid == 0 &&
953 			cqe->command_id >= NVME_AQ_BLK_MQ_DEPTH)) {
954 		nvme_complete_async_event(&nvmeq->dev->ctrl,
955 				cqe->status, &cqe->result);
956 		return;
957 	}
958 
959 	nvmeq->cqe_seen = 1;
960 	req = blk_mq_tag_to_rq(*nvmeq->tags, cqe->command_id);
961 	nvme_end_request(req, cqe->status, cqe->result);
962 }
963 
964 static inline bool nvme_read_cqe(struct nvme_queue *nvmeq,
965 		struct nvme_completion *cqe)
966 {
967 	if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase)) {
968 		*cqe = nvmeq->cqes[nvmeq->cq_head];
969 
970 		if (++nvmeq->cq_head == nvmeq->q_depth) {
971 			nvmeq->cq_head = 0;
972 			nvmeq->cq_phase = !nvmeq->cq_phase;
973 		}
974 		return true;
975 	}
976 	return false;
977 }
978 
979 static void nvme_process_cq(struct nvme_queue *nvmeq)
980 {
981 	struct nvme_completion cqe;
982 	int consumed = 0;
983 
984 	while (nvme_read_cqe(nvmeq, &cqe)) {
985 		nvme_handle_cqe(nvmeq, &cqe);
986 		consumed++;
987 	}
988 
989 	if (consumed)
990 		nvme_ring_cq_doorbell(nvmeq);
991 }
992 
993 static irqreturn_t nvme_irq(int irq, void *data)
994 {
995 	irqreturn_t result;
996 	struct nvme_queue *nvmeq = data;
997 	spin_lock(&nvmeq->q_lock);
998 	nvme_process_cq(nvmeq);
999 	result = nvmeq->cqe_seen ? IRQ_HANDLED : IRQ_NONE;
1000 	nvmeq->cqe_seen = 0;
1001 	spin_unlock(&nvmeq->q_lock);
1002 	return result;
1003 }
1004 
1005 static irqreturn_t nvme_irq_check(int irq, void *data)
1006 {
1007 	struct nvme_queue *nvmeq = data;
1008 	if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase))
1009 		return IRQ_WAKE_THREAD;
1010 	return IRQ_NONE;
1011 }
1012 
1013 static int __nvme_poll(struct nvme_queue *nvmeq, unsigned int tag)
1014 {
1015 	struct nvme_completion cqe;
1016 	int found = 0, consumed = 0;
1017 
1018 	if (!nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase))
1019 		return 0;
1020 
1021 	spin_lock_irq(&nvmeq->q_lock);
1022 	while (nvme_read_cqe(nvmeq, &cqe)) {
1023 		nvme_handle_cqe(nvmeq, &cqe);
1024 		consumed++;
1025 
1026 		if (tag == cqe.command_id) {
1027 			found = 1;
1028 			break;
1029 		}
1030        }
1031 
1032 	if (consumed)
1033 		nvme_ring_cq_doorbell(nvmeq);
1034 	spin_unlock_irq(&nvmeq->q_lock);
1035 
1036 	return found;
1037 }
1038 
1039 static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
1040 {
1041 	struct nvme_queue *nvmeq = hctx->driver_data;
1042 
1043 	return __nvme_poll(nvmeq, tag);
1044 }
1045 
1046 static void nvme_pci_submit_async_event(struct nvme_ctrl *ctrl)
1047 {
1048 	struct nvme_dev *dev = to_nvme_dev(ctrl);
1049 	struct nvme_queue *nvmeq = &dev->queues[0];
1050 	struct nvme_command c;
1051 
1052 	memset(&c, 0, sizeof(c));
1053 	c.common.opcode = nvme_admin_async_event;
1054 	c.common.command_id = NVME_AQ_BLK_MQ_DEPTH;
1055 
1056 	spin_lock_irq(&nvmeq->q_lock);
1057 	__nvme_submit_cmd(nvmeq, &c);
1058 	spin_unlock_irq(&nvmeq->q_lock);
1059 }
1060 
1061 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
1062 {
1063 	struct nvme_command c;
1064 
1065 	memset(&c, 0, sizeof(c));
1066 	c.delete_queue.opcode = opcode;
1067 	c.delete_queue.qid = cpu_to_le16(id);
1068 
1069 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1070 }
1071 
1072 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
1073 						struct nvme_queue *nvmeq)
1074 {
1075 	struct nvme_command c;
1076 	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
1077 
1078 	/*
1079 	 * Note: we (ab)use the fact that the prp fields survive if no data
1080 	 * is attached to the request.
1081 	 */
1082 	memset(&c, 0, sizeof(c));
1083 	c.create_cq.opcode = nvme_admin_create_cq;
1084 	c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
1085 	c.create_cq.cqid = cpu_to_le16(qid);
1086 	c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
1087 	c.create_cq.cq_flags = cpu_to_le16(flags);
1088 	c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
1089 
1090 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1091 }
1092 
1093 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
1094 						struct nvme_queue *nvmeq)
1095 {
1096 	struct nvme_command c;
1097 	int flags = NVME_QUEUE_PHYS_CONTIG;
1098 
1099 	/*
1100 	 * Note: we (ab)use the fact that the prp fields survive if no data
1101 	 * is attached to the request.
1102 	 */
1103 	memset(&c, 0, sizeof(c));
1104 	c.create_sq.opcode = nvme_admin_create_sq;
1105 	c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
1106 	c.create_sq.sqid = cpu_to_le16(qid);
1107 	c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
1108 	c.create_sq.sq_flags = cpu_to_le16(flags);
1109 	c.create_sq.cqid = cpu_to_le16(qid);
1110 
1111 	return nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1112 }
1113 
1114 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
1115 {
1116 	return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
1117 }
1118 
1119 static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
1120 {
1121 	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
1122 }
1123 
1124 static void abort_endio(struct request *req, blk_status_t error)
1125 {
1126 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
1127 	struct nvme_queue *nvmeq = iod->nvmeq;
1128 
1129 	dev_warn(nvmeq->dev->ctrl.device,
1130 		 "Abort status: 0x%x", nvme_req(req)->status);
1131 	atomic_inc(&nvmeq->dev->ctrl.abort_limit);
1132 	blk_mq_free_request(req);
1133 }
1134 
1135 static bool nvme_should_reset(struct nvme_dev *dev, u32 csts)
1136 {
1137 
1138 	/* If true, indicates loss of adapter communication, possibly by a
1139 	 * NVMe Subsystem reset.
1140 	 */
1141 	bool nssro = dev->subsystem && (csts & NVME_CSTS_NSSRO);
1142 
1143 	/* If there is a reset/reinit ongoing, we shouldn't reset again. */
1144 	switch (dev->ctrl.state) {
1145 	case NVME_CTRL_RESETTING:
1146 	case NVME_CTRL_CONNECTING:
1147 		return false;
1148 	default:
1149 		break;
1150 	}
1151 
1152 	/* We shouldn't reset unless the controller is on fatal error state
1153 	 * _or_ if we lost the communication with it.
1154 	 */
1155 	if (!(csts & NVME_CSTS_CFS) && !nssro)
1156 		return false;
1157 
1158 	return true;
1159 }
1160 
1161 static void nvme_warn_reset(struct nvme_dev *dev, u32 csts)
1162 {
1163 	/* Read a config register to help see what died. */
1164 	u16 pci_status;
1165 	int result;
1166 
1167 	result = pci_read_config_word(to_pci_dev(dev->dev), PCI_STATUS,
1168 				      &pci_status);
1169 	if (result == PCIBIOS_SUCCESSFUL)
1170 		dev_warn(dev->ctrl.device,
1171 			 "controller is down; will reset: CSTS=0x%x, PCI_STATUS=0x%hx\n",
1172 			 csts, pci_status);
1173 	else
1174 		dev_warn(dev->ctrl.device,
1175 			 "controller is down; will reset: CSTS=0x%x, PCI_STATUS read failed (%d)\n",
1176 			 csts, result);
1177 }
1178 
1179 static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
1180 {
1181 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
1182 	struct nvme_queue *nvmeq = iod->nvmeq;
1183 	struct nvme_dev *dev = nvmeq->dev;
1184 	struct request *abort_req;
1185 	struct nvme_command cmd;
1186 	u32 csts = readl(dev->bar + NVME_REG_CSTS);
1187 
1188 	/* If PCI error recovery process is happening, we cannot reset or
1189 	 * the recovery mechanism will surely fail.
1190 	 */
1191 	mb();
1192 	if (pci_channel_offline(to_pci_dev(dev->dev)))
1193 		return BLK_EH_RESET_TIMER;
1194 
1195 	/*
1196 	 * Reset immediately if the controller is failed
1197 	 */
1198 	if (nvme_should_reset(dev, csts)) {
1199 		nvme_warn_reset(dev, csts);
1200 		nvme_dev_disable(dev, false);
1201 		nvme_reset_ctrl(&dev->ctrl);
1202 		return BLK_EH_HANDLED;
1203 	}
1204 
1205 	/*
1206 	 * Did we miss an interrupt?
1207 	 */
1208 	if (__nvme_poll(nvmeq, req->tag)) {
1209 		dev_warn(dev->ctrl.device,
1210 			 "I/O %d QID %d timeout, completion polled\n",
1211 			 req->tag, nvmeq->qid);
1212 		return BLK_EH_HANDLED;
1213 	}
1214 
1215 	/*
1216 	 * Shutdown immediately if controller times out while starting. The
1217 	 * reset work will see the pci device disabled when it gets the forced
1218 	 * cancellation error. All outstanding requests are completed on
1219 	 * shutdown, so we return BLK_EH_HANDLED.
1220 	 */
1221 	switch (dev->ctrl.state) {
1222 	case NVME_CTRL_CONNECTING:
1223 	case NVME_CTRL_RESETTING:
1224 		dev_warn(dev->ctrl.device,
1225 			 "I/O %d QID %d timeout, disable controller\n",
1226 			 req->tag, nvmeq->qid);
1227 		nvme_dev_disable(dev, false);
1228 		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
1229 		return BLK_EH_HANDLED;
1230 	default:
1231 		break;
1232 	}
1233 
1234 	/*
1235  	 * Shutdown the controller immediately and schedule a reset if the
1236  	 * command was already aborted once before and still hasn't been
1237  	 * returned to the driver, or if this is the admin queue.
1238 	 */
1239 	if (!nvmeq->qid || iod->aborted) {
1240 		dev_warn(dev->ctrl.device,
1241 			 "I/O %d QID %d timeout, reset controller\n",
1242 			 req->tag, nvmeq->qid);
1243 		nvme_dev_disable(dev, false);
1244 		nvme_reset_ctrl(&dev->ctrl);
1245 
1246 		/*
1247 		 * Mark the request as handled, since the inline shutdown
1248 		 * forces all outstanding requests to complete.
1249 		 */
1250 		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
1251 		return BLK_EH_HANDLED;
1252 	}
1253 
1254 	if (atomic_dec_return(&dev->ctrl.abort_limit) < 0) {
1255 		atomic_inc(&dev->ctrl.abort_limit);
1256 		return BLK_EH_RESET_TIMER;
1257 	}
1258 	iod->aborted = 1;
1259 
1260 	memset(&cmd, 0, sizeof(cmd));
1261 	cmd.abort.opcode = nvme_admin_abort_cmd;
1262 	cmd.abort.cid = req->tag;
1263 	cmd.abort.sqid = cpu_to_le16(nvmeq->qid);
1264 
1265 	dev_warn(nvmeq->dev->ctrl.device,
1266 		"I/O %d QID %d timeout, aborting\n",
1267 		 req->tag, nvmeq->qid);
1268 
1269 	abort_req = nvme_alloc_request(dev->ctrl.admin_q, &cmd,
1270 			BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
1271 	if (IS_ERR(abort_req)) {
1272 		atomic_inc(&dev->ctrl.abort_limit);
1273 		return BLK_EH_RESET_TIMER;
1274 	}
1275 
1276 	abort_req->timeout = ADMIN_TIMEOUT;
1277 	abort_req->end_io_data = NULL;
1278 	blk_execute_rq_nowait(abort_req->q, NULL, abort_req, 0, abort_endio);
1279 
1280 	/*
1281 	 * The aborted req will be completed on receiving the abort req.
1282 	 * We enable the timer again. If hit twice, it'll cause a device reset,
1283 	 * as the device then is in a faulty state.
1284 	 */
1285 	return BLK_EH_RESET_TIMER;
1286 }
1287 
1288 static void nvme_free_queue(struct nvme_queue *nvmeq)
1289 {
1290 	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
1291 				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
1292 	if (nvmeq->sq_cmds)
1293 		dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
1294 					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
1295 }
1296 
1297 static void nvme_free_queues(struct nvme_dev *dev, int lowest)
1298 {
1299 	int i;
1300 
1301 	for (i = dev->ctrl.queue_count - 1; i >= lowest; i--) {
1302 		dev->ctrl.queue_count--;
1303 		nvme_free_queue(&dev->queues[i]);
1304 	}
1305 }
1306 
1307 /**
1308  * nvme_suspend_queue - put queue into suspended state
1309  * @nvmeq - queue to suspend
1310  */
1311 static int nvme_suspend_queue(struct nvme_queue *nvmeq)
1312 {
1313 	int vector;
1314 
1315 	spin_lock_irq(&nvmeq->q_lock);
1316 	if (nvmeq->cq_vector == -1) {
1317 		spin_unlock_irq(&nvmeq->q_lock);
1318 		return 1;
1319 	}
1320 	vector = nvmeq->cq_vector;
1321 	nvmeq->dev->online_queues--;
1322 	nvmeq->cq_vector = -1;
1323 	spin_unlock_irq(&nvmeq->q_lock);
1324 
1325 	if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
1326 		blk_mq_quiesce_queue(nvmeq->dev->ctrl.admin_q);
1327 
1328 	pci_free_irq(to_pci_dev(nvmeq->dev->dev), vector, nvmeq);
1329 
1330 	return 0;
1331 }
1332 
1333 static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
1334 {
1335 	struct nvme_queue *nvmeq = &dev->queues[0];
1336 
1337 	if (shutdown)
1338 		nvme_shutdown_ctrl(&dev->ctrl);
1339 	else
1340 		nvme_disable_ctrl(&dev->ctrl, dev->ctrl.cap);
1341 
1342 	spin_lock_irq(&nvmeq->q_lock);
1343 	nvme_process_cq(nvmeq);
1344 	spin_unlock_irq(&nvmeq->q_lock);
1345 }
1346 
1347 static int nvme_cmb_qdepth(struct nvme_dev *dev, int nr_io_queues,
1348 				int entry_size)
1349 {
1350 	int q_depth = dev->q_depth;
1351 	unsigned q_size_aligned = roundup(q_depth * entry_size,
1352 					  dev->ctrl.page_size);
1353 
1354 	if (q_size_aligned * nr_io_queues > dev->cmb_size) {
1355 		u64 mem_per_q = div_u64(dev->cmb_size, nr_io_queues);
1356 		mem_per_q = round_down(mem_per_q, dev->ctrl.page_size);
1357 		q_depth = div_u64(mem_per_q, entry_size);
1358 
1359 		/*
1360 		 * Ensure the reduced q_depth is above some threshold where it
1361 		 * would be better to map queues in system memory with the
1362 		 * original depth
1363 		 */
1364 		if (q_depth < 64)
1365 			return -ENOMEM;
1366 	}
1367 
1368 	return q_depth;
1369 }
1370 
1371 static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
1372 				int qid, int depth)
1373 {
1374 	/* CMB SQEs will be mapped before creation */
1375 	if (qid && dev->cmb && use_cmb_sqes && (dev->cmbsz & NVME_CMBSZ_SQS))
1376 		return 0;
1377 
1378 	nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(depth),
1379 					    &nvmeq->sq_dma_addr, GFP_KERNEL);
1380 	if (!nvmeq->sq_cmds)
1381 		return -ENOMEM;
1382 	return 0;
1383 }
1384 
1385 static int nvme_alloc_queue(struct nvme_dev *dev, int qid, int depth)
1386 {
1387 	struct nvme_queue *nvmeq = &dev->queues[qid];
1388 
1389 	if (dev->ctrl.queue_count > qid)
1390 		return 0;
1391 
1392 	nvmeq->cqes = dma_zalloc_coherent(dev->dev, CQ_SIZE(depth),
1393 					  &nvmeq->cq_dma_addr, GFP_KERNEL);
1394 	if (!nvmeq->cqes)
1395 		goto free_nvmeq;
1396 
1397 	if (nvme_alloc_sq_cmds(dev, nvmeq, qid, depth))
1398 		goto free_cqdma;
1399 
1400 	nvmeq->q_dmadev = dev->dev;
1401 	nvmeq->dev = dev;
1402 	spin_lock_init(&nvmeq->q_lock);
1403 	nvmeq->cq_head = 0;
1404 	nvmeq->cq_phase = 1;
1405 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1406 	nvmeq->q_depth = depth;
1407 	nvmeq->qid = qid;
1408 	nvmeq->cq_vector = -1;
1409 	dev->ctrl.queue_count++;
1410 
1411 	return 0;
1412 
1413  free_cqdma:
1414 	dma_free_coherent(dev->dev, CQ_SIZE(depth), (void *)nvmeq->cqes,
1415 							nvmeq->cq_dma_addr);
1416  free_nvmeq:
1417 	return -ENOMEM;
1418 }
1419 
1420 static int queue_request_irq(struct nvme_queue *nvmeq)
1421 {
1422 	struct pci_dev *pdev = to_pci_dev(nvmeq->dev->dev);
1423 	int nr = nvmeq->dev->ctrl.instance;
1424 
1425 	if (use_threaded_interrupts) {
1426 		return pci_request_irq(pdev, nvmeq->cq_vector, nvme_irq_check,
1427 				nvme_irq, nvmeq, "nvme%dq%d", nr, nvmeq->qid);
1428 	} else {
1429 		return pci_request_irq(pdev, nvmeq->cq_vector, nvme_irq,
1430 				NULL, nvmeq, "nvme%dq%d", nr, nvmeq->qid);
1431 	}
1432 }
1433 
1434 static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
1435 {
1436 	struct nvme_dev *dev = nvmeq->dev;
1437 
1438 	spin_lock_irq(&nvmeq->q_lock);
1439 	nvmeq->sq_tail = 0;
1440 	nvmeq->cq_head = 0;
1441 	nvmeq->cq_phase = 1;
1442 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
1443 	memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth));
1444 	nvme_dbbuf_init(dev, nvmeq, qid);
1445 	dev->online_queues++;
1446 	spin_unlock_irq(&nvmeq->q_lock);
1447 }
1448 
1449 static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
1450 {
1451 	struct nvme_dev *dev = nvmeq->dev;
1452 	int result;
1453 
1454 	if (dev->cmb && use_cmb_sqes && (dev->cmbsz & NVME_CMBSZ_SQS)) {
1455 		unsigned offset = (qid - 1) * roundup(SQ_SIZE(nvmeq->q_depth),
1456 						      dev->ctrl.page_size);
1457 		nvmeq->sq_dma_addr = dev->cmb_bus_addr + offset;
1458 		nvmeq->sq_cmds_io = dev->cmb + offset;
1459 	}
1460 
1461 	/*
1462 	 * A queue's vector matches the queue identifier unless the controller
1463 	 * has only one vector available.
1464 	 */
1465 	nvmeq->cq_vector = dev->num_vecs == 1 ? 0 : qid;
1466 	result = adapter_alloc_cq(dev, qid, nvmeq);
1467 	if (result < 0)
1468 		goto release_vector;
1469 
1470 	result = adapter_alloc_sq(dev, qid, nvmeq);
1471 	if (result < 0)
1472 		goto release_cq;
1473 
1474 	nvme_init_queue(nvmeq, qid);
1475 	result = queue_request_irq(nvmeq);
1476 	if (result < 0)
1477 		goto release_sq;
1478 
1479 	return result;
1480 
1481  release_sq:
1482 	dev->online_queues--;
1483 	adapter_delete_sq(dev, qid);
1484  release_cq:
1485 	adapter_delete_cq(dev, qid);
1486  release_vector:
1487 	nvmeq->cq_vector = -1;
1488 	return result;
1489 }
1490 
1491 static const struct blk_mq_ops nvme_mq_admin_ops = {
1492 	.queue_rq	= nvme_queue_rq,
1493 	.complete	= nvme_pci_complete_rq,
1494 	.init_hctx	= nvme_admin_init_hctx,
1495 	.exit_hctx      = nvme_admin_exit_hctx,
1496 	.init_request	= nvme_init_request,
1497 	.timeout	= nvme_timeout,
1498 };
1499 
1500 static const struct blk_mq_ops nvme_mq_ops = {
1501 	.queue_rq	= nvme_queue_rq,
1502 	.complete	= nvme_pci_complete_rq,
1503 	.init_hctx	= nvme_init_hctx,
1504 	.init_request	= nvme_init_request,
1505 	.map_queues	= nvme_pci_map_queues,
1506 	.timeout	= nvme_timeout,
1507 	.poll		= nvme_poll,
1508 };
1509 
1510 static void nvme_dev_remove_admin(struct nvme_dev *dev)
1511 {
1512 	if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q)) {
1513 		/*
1514 		 * If the controller was reset during removal, it's possible
1515 		 * user requests may be waiting on a stopped queue. Start the
1516 		 * queue to flush these to completion.
1517 		 */
1518 		blk_mq_unquiesce_queue(dev->ctrl.admin_q);
1519 		blk_cleanup_queue(dev->ctrl.admin_q);
1520 		blk_mq_free_tag_set(&dev->admin_tagset);
1521 	}
1522 }
1523 
1524 static int nvme_alloc_admin_tags(struct nvme_dev *dev)
1525 {
1526 	if (!dev->ctrl.admin_q) {
1527 		dev->admin_tagset.ops = &nvme_mq_admin_ops;
1528 		dev->admin_tagset.nr_hw_queues = 1;
1529 
1530 		dev->admin_tagset.queue_depth = NVME_AQ_MQ_TAG_DEPTH;
1531 		dev->admin_tagset.timeout = ADMIN_TIMEOUT;
1532 		dev->admin_tagset.numa_node = dev_to_node(dev->dev);
1533 		dev->admin_tagset.cmd_size = nvme_pci_cmd_size(dev, false);
1534 		dev->admin_tagset.flags = BLK_MQ_F_NO_SCHED;
1535 		dev->admin_tagset.driver_data = dev;
1536 
1537 		if (blk_mq_alloc_tag_set(&dev->admin_tagset))
1538 			return -ENOMEM;
1539 		dev->ctrl.admin_tagset = &dev->admin_tagset;
1540 
1541 		dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
1542 		if (IS_ERR(dev->ctrl.admin_q)) {
1543 			blk_mq_free_tag_set(&dev->admin_tagset);
1544 			return -ENOMEM;
1545 		}
1546 		if (!blk_get_queue(dev->ctrl.admin_q)) {
1547 			nvme_dev_remove_admin(dev);
1548 			dev->ctrl.admin_q = NULL;
1549 			return -ENODEV;
1550 		}
1551 	} else
1552 		blk_mq_unquiesce_queue(dev->ctrl.admin_q);
1553 
1554 	return 0;
1555 }
1556 
1557 static unsigned long db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
1558 {
1559 	return NVME_REG_DBS + ((nr_io_queues + 1) * 8 * dev->db_stride);
1560 }
1561 
1562 static int nvme_remap_bar(struct nvme_dev *dev, unsigned long size)
1563 {
1564 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1565 
1566 	if (size <= dev->bar_mapped_size)
1567 		return 0;
1568 	if (size > pci_resource_len(pdev, 0))
1569 		return -ENOMEM;
1570 	if (dev->bar)
1571 		iounmap(dev->bar);
1572 	dev->bar = ioremap(pci_resource_start(pdev, 0), size);
1573 	if (!dev->bar) {
1574 		dev->bar_mapped_size = 0;
1575 		return -ENOMEM;
1576 	}
1577 	dev->bar_mapped_size = size;
1578 	dev->dbs = dev->bar + NVME_REG_DBS;
1579 
1580 	return 0;
1581 }
1582 
1583 static int nvme_pci_configure_admin_queue(struct nvme_dev *dev)
1584 {
1585 	int result;
1586 	u32 aqa;
1587 	struct nvme_queue *nvmeq;
1588 
1589 	result = nvme_remap_bar(dev, db_bar_size(dev, 0));
1590 	if (result < 0)
1591 		return result;
1592 
1593 	dev->subsystem = readl(dev->bar + NVME_REG_VS) >= NVME_VS(1, 1, 0) ?
1594 				NVME_CAP_NSSRC(dev->ctrl.cap) : 0;
1595 
1596 	if (dev->subsystem &&
1597 	    (readl(dev->bar + NVME_REG_CSTS) & NVME_CSTS_NSSRO))
1598 		writel(NVME_CSTS_NSSRO, dev->bar + NVME_REG_CSTS);
1599 
1600 	result = nvme_disable_ctrl(&dev->ctrl, dev->ctrl.cap);
1601 	if (result < 0)
1602 		return result;
1603 
1604 	result = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH);
1605 	if (result)
1606 		return result;
1607 
1608 	nvmeq = &dev->queues[0];
1609 	aqa = nvmeq->q_depth - 1;
1610 	aqa |= aqa << 16;
1611 
1612 	writel(aqa, dev->bar + NVME_REG_AQA);
1613 	lo_hi_writeq(nvmeq->sq_dma_addr, dev->bar + NVME_REG_ASQ);
1614 	lo_hi_writeq(nvmeq->cq_dma_addr, dev->bar + NVME_REG_ACQ);
1615 
1616 	result = nvme_enable_ctrl(&dev->ctrl, dev->ctrl.cap);
1617 	if (result)
1618 		return result;
1619 
1620 	nvmeq->cq_vector = 0;
1621 	nvme_init_queue(nvmeq, 0);
1622 	result = queue_request_irq(nvmeq);
1623 	if (result) {
1624 		nvmeq->cq_vector = -1;
1625 		return result;
1626 	}
1627 
1628 	return result;
1629 }
1630 
1631 static int nvme_create_io_queues(struct nvme_dev *dev)
1632 {
1633 	unsigned i, max;
1634 	int ret = 0;
1635 
1636 	for (i = dev->ctrl.queue_count; i <= dev->max_qid; i++) {
1637 		if (nvme_alloc_queue(dev, i, dev->q_depth)) {
1638 			ret = -ENOMEM;
1639 			break;
1640 		}
1641 	}
1642 
1643 	max = min(dev->max_qid, dev->ctrl.queue_count - 1);
1644 	for (i = dev->online_queues; i <= max; i++) {
1645 		ret = nvme_create_queue(&dev->queues[i], i);
1646 		if (ret)
1647 			break;
1648 	}
1649 
1650 	/*
1651 	 * Ignore failing Create SQ/CQ commands, we can continue with less
1652 	 * than the desired amount of queues, and even a controller without
1653 	 * I/O queues can still be used to issue admin commands.  This might
1654 	 * be useful to upgrade a buggy firmware for example.
1655 	 */
1656 	return ret >= 0 ? 0 : ret;
1657 }
1658 
1659 static ssize_t nvme_cmb_show(struct device *dev,
1660 			     struct device_attribute *attr,
1661 			     char *buf)
1662 {
1663 	struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
1664 
1665 	return scnprintf(buf, PAGE_SIZE, "cmbloc : x%08x\ncmbsz  : x%08x\n",
1666 		       ndev->cmbloc, ndev->cmbsz);
1667 }
1668 static DEVICE_ATTR(cmb, S_IRUGO, nvme_cmb_show, NULL);
1669 
1670 static u64 nvme_cmb_size_unit(struct nvme_dev *dev)
1671 {
1672 	u8 szu = (dev->cmbsz >> NVME_CMBSZ_SZU_SHIFT) & NVME_CMBSZ_SZU_MASK;
1673 
1674 	return 1ULL << (12 + 4 * szu);
1675 }
1676 
1677 static u32 nvme_cmb_size(struct nvme_dev *dev)
1678 {
1679 	return (dev->cmbsz >> NVME_CMBSZ_SZ_SHIFT) & NVME_CMBSZ_SZ_MASK;
1680 }
1681 
1682 static void nvme_map_cmb(struct nvme_dev *dev)
1683 {
1684 	u64 size, offset;
1685 	resource_size_t bar_size;
1686 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1687 	int bar;
1688 
1689 	dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
1690 	if (!dev->cmbsz)
1691 		return;
1692 	dev->cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
1693 
1694 	if (!use_cmb_sqes)
1695 		return;
1696 
1697 	size = nvme_cmb_size_unit(dev) * nvme_cmb_size(dev);
1698 	offset = nvme_cmb_size_unit(dev) * NVME_CMB_OFST(dev->cmbloc);
1699 	bar = NVME_CMB_BIR(dev->cmbloc);
1700 	bar_size = pci_resource_len(pdev, bar);
1701 
1702 	if (offset > bar_size)
1703 		return;
1704 
1705 	/*
1706 	 * Controllers may support a CMB size larger than their BAR,
1707 	 * for example, due to being behind a bridge. Reduce the CMB to
1708 	 * the reported size of the BAR
1709 	 */
1710 	if (size > bar_size - offset)
1711 		size = bar_size - offset;
1712 
1713 	dev->cmb = ioremap_wc(pci_resource_start(pdev, bar) + offset, size);
1714 	if (!dev->cmb)
1715 		return;
1716 	dev->cmb_bus_addr = pci_bus_address(pdev, bar) + offset;
1717 	dev->cmb_size = size;
1718 
1719 	if (sysfs_add_file_to_group(&dev->ctrl.device->kobj,
1720 				    &dev_attr_cmb.attr, NULL))
1721 		dev_warn(dev->ctrl.device,
1722 			 "failed to add sysfs attribute for CMB\n");
1723 }
1724 
1725 static inline void nvme_release_cmb(struct nvme_dev *dev)
1726 {
1727 	if (dev->cmb) {
1728 		iounmap(dev->cmb);
1729 		dev->cmb = NULL;
1730 		sysfs_remove_file_from_group(&dev->ctrl.device->kobj,
1731 					     &dev_attr_cmb.attr, NULL);
1732 		dev->cmbsz = 0;
1733 	}
1734 }
1735 
1736 static int nvme_set_host_mem(struct nvme_dev *dev, u32 bits)
1737 {
1738 	u64 dma_addr = dev->host_mem_descs_dma;
1739 	struct nvme_command c;
1740 	int ret;
1741 
1742 	memset(&c, 0, sizeof(c));
1743 	c.features.opcode	= nvme_admin_set_features;
1744 	c.features.fid		= cpu_to_le32(NVME_FEAT_HOST_MEM_BUF);
1745 	c.features.dword11	= cpu_to_le32(bits);
1746 	c.features.dword12	= cpu_to_le32(dev->host_mem_size >>
1747 					      ilog2(dev->ctrl.page_size));
1748 	c.features.dword13	= cpu_to_le32(lower_32_bits(dma_addr));
1749 	c.features.dword14	= cpu_to_le32(upper_32_bits(dma_addr));
1750 	c.features.dword15	= cpu_to_le32(dev->nr_host_mem_descs);
1751 
1752 	ret = nvme_submit_sync_cmd(dev->ctrl.admin_q, &c, NULL, 0);
1753 	if (ret) {
1754 		dev_warn(dev->ctrl.device,
1755 			 "failed to set host mem (err %d, flags %#x).\n",
1756 			 ret, bits);
1757 	}
1758 	return ret;
1759 }
1760 
1761 static void nvme_free_host_mem(struct nvme_dev *dev)
1762 {
1763 	int i;
1764 
1765 	for (i = 0; i < dev->nr_host_mem_descs; i++) {
1766 		struct nvme_host_mem_buf_desc *desc = &dev->host_mem_descs[i];
1767 		size_t size = le32_to_cpu(desc->size) * dev->ctrl.page_size;
1768 
1769 		dma_free_coherent(dev->dev, size, dev->host_mem_desc_bufs[i],
1770 				le64_to_cpu(desc->addr));
1771 	}
1772 
1773 	kfree(dev->host_mem_desc_bufs);
1774 	dev->host_mem_desc_bufs = NULL;
1775 	dma_free_coherent(dev->dev,
1776 			dev->nr_host_mem_descs * sizeof(*dev->host_mem_descs),
1777 			dev->host_mem_descs, dev->host_mem_descs_dma);
1778 	dev->host_mem_descs = NULL;
1779 	dev->nr_host_mem_descs = 0;
1780 }
1781 
1782 static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred,
1783 		u32 chunk_size)
1784 {
1785 	struct nvme_host_mem_buf_desc *descs;
1786 	u32 max_entries, len;
1787 	dma_addr_t descs_dma;
1788 	int i = 0;
1789 	void **bufs;
1790 	u64 size, tmp;
1791 
1792 	tmp = (preferred + chunk_size - 1);
1793 	do_div(tmp, chunk_size);
1794 	max_entries = tmp;
1795 
1796 	if (dev->ctrl.hmmaxd && dev->ctrl.hmmaxd < max_entries)
1797 		max_entries = dev->ctrl.hmmaxd;
1798 
1799 	descs = dma_zalloc_coherent(dev->dev, max_entries * sizeof(*descs),
1800 			&descs_dma, GFP_KERNEL);
1801 	if (!descs)
1802 		goto out;
1803 
1804 	bufs = kcalloc(max_entries, sizeof(*bufs), GFP_KERNEL);
1805 	if (!bufs)
1806 		goto out_free_descs;
1807 
1808 	for (size = 0; size < preferred && i < max_entries; size += len) {
1809 		dma_addr_t dma_addr;
1810 
1811 		len = min_t(u64, chunk_size, preferred - size);
1812 		bufs[i] = dma_alloc_attrs(dev->dev, len, &dma_addr, GFP_KERNEL,
1813 				DMA_ATTR_NO_KERNEL_MAPPING | DMA_ATTR_NO_WARN);
1814 		if (!bufs[i])
1815 			break;
1816 
1817 		descs[i].addr = cpu_to_le64(dma_addr);
1818 		descs[i].size = cpu_to_le32(len / dev->ctrl.page_size);
1819 		i++;
1820 	}
1821 
1822 	if (!size)
1823 		goto out_free_bufs;
1824 
1825 	dev->nr_host_mem_descs = i;
1826 	dev->host_mem_size = size;
1827 	dev->host_mem_descs = descs;
1828 	dev->host_mem_descs_dma = descs_dma;
1829 	dev->host_mem_desc_bufs = bufs;
1830 	return 0;
1831 
1832 out_free_bufs:
1833 	while (--i >= 0) {
1834 		size_t size = le32_to_cpu(descs[i].size) * dev->ctrl.page_size;
1835 
1836 		dma_free_coherent(dev->dev, size, bufs[i],
1837 				le64_to_cpu(descs[i].addr));
1838 	}
1839 
1840 	kfree(bufs);
1841 out_free_descs:
1842 	dma_free_coherent(dev->dev, max_entries * sizeof(*descs), descs,
1843 			descs_dma);
1844 out:
1845 	dev->host_mem_descs = NULL;
1846 	return -ENOMEM;
1847 }
1848 
1849 static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred)
1850 {
1851 	u32 chunk_size;
1852 
1853 	/* start big and work our way down */
1854 	for (chunk_size = min_t(u64, preferred, PAGE_SIZE * MAX_ORDER_NR_PAGES);
1855 	     chunk_size >= max_t(u32, dev->ctrl.hmminds * 4096, PAGE_SIZE * 2);
1856 	     chunk_size /= 2) {
1857 		if (!__nvme_alloc_host_mem(dev, preferred, chunk_size)) {
1858 			if (!min || dev->host_mem_size >= min)
1859 				return 0;
1860 			nvme_free_host_mem(dev);
1861 		}
1862 	}
1863 
1864 	return -ENOMEM;
1865 }
1866 
1867 static int nvme_setup_host_mem(struct nvme_dev *dev)
1868 {
1869 	u64 max = (u64)max_host_mem_size_mb * SZ_1M;
1870 	u64 preferred = (u64)dev->ctrl.hmpre * 4096;
1871 	u64 min = (u64)dev->ctrl.hmmin * 4096;
1872 	u32 enable_bits = NVME_HOST_MEM_ENABLE;
1873 	int ret;
1874 
1875 	preferred = min(preferred, max);
1876 	if (min > max) {
1877 		dev_warn(dev->ctrl.device,
1878 			"min host memory (%lld MiB) above limit (%d MiB).\n",
1879 			min >> ilog2(SZ_1M), max_host_mem_size_mb);
1880 		nvme_free_host_mem(dev);
1881 		return 0;
1882 	}
1883 
1884 	/*
1885 	 * If we already have a buffer allocated check if we can reuse it.
1886 	 */
1887 	if (dev->host_mem_descs) {
1888 		if (dev->host_mem_size >= min)
1889 			enable_bits |= NVME_HOST_MEM_RETURN;
1890 		else
1891 			nvme_free_host_mem(dev);
1892 	}
1893 
1894 	if (!dev->host_mem_descs) {
1895 		if (nvme_alloc_host_mem(dev, min, preferred)) {
1896 			dev_warn(dev->ctrl.device,
1897 				"failed to allocate host memory buffer.\n");
1898 			return 0; /* controller must work without HMB */
1899 		}
1900 
1901 		dev_info(dev->ctrl.device,
1902 			"allocated %lld MiB host memory buffer.\n",
1903 			dev->host_mem_size >> ilog2(SZ_1M));
1904 	}
1905 
1906 	ret = nvme_set_host_mem(dev, enable_bits);
1907 	if (ret)
1908 		nvme_free_host_mem(dev);
1909 	return ret;
1910 }
1911 
1912 static int nvme_setup_io_queues(struct nvme_dev *dev)
1913 {
1914 	struct nvme_queue *adminq = &dev->queues[0];
1915 	struct pci_dev *pdev = to_pci_dev(dev->dev);
1916 	int result, nr_io_queues;
1917 	unsigned long size;
1918 
1919 	struct irq_affinity affd = {
1920 		.pre_vectors = 1
1921 	};
1922 
1923 	nr_io_queues = num_possible_cpus();
1924 	result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
1925 	if (result < 0)
1926 		return result;
1927 
1928 	if (nr_io_queues == 0)
1929 		return 0;
1930 
1931 	if (dev->cmb && (dev->cmbsz & NVME_CMBSZ_SQS)) {
1932 		result = nvme_cmb_qdepth(dev, nr_io_queues,
1933 				sizeof(struct nvme_command));
1934 		if (result > 0)
1935 			dev->q_depth = result;
1936 		else
1937 			nvme_release_cmb(dev);
1938 	}
1939 
1940 	do {
1941 		size = db_bar_size(dev, nr_io_queues);
1942 		result = nvme_remap_bar(dev, size);
1943 		if (!result)
1944 			break;
1945 		if (!--nr_io_queues)
1946 			return -ENOMEM;
1947 	} while (1);
1948 	adminq->q_db = dev->dbs;
1949 
1950 	/* Deregister the admin queue's interrupt */
1951 	pci_free_irq(pdev, 0, adminq);
1952 
1953 	/*
1954 	 * If we enable msix early due to not intx, disable it again before
1955 	 * setting up the full range we need.
1956 	 */
1957 	pci_free_irq_vectors(pdev);
1958 	result = pci_alloc_irq_vectors_affinity(pdev, 1, nr_io_queues + 1,
1959 			PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
1960 	if (result <= 0)
1961 		return -EIO;
1962 	dev->num_vecs = result;
1963 	dev->max_qid = max(result - 1, 1);
1964 
1965 	/*
1966 	 * Should investigate if there's a performance win from allocating
1967 	 * more queues than interrupt vectors; it might allow the submission
1968 	 * path to scale better, even if the receive path is limited by the
1969 	 * number of interrupts.
1970 	 */
1971 
1972 	result = queue_request_irq(adminq);
1973 	if (result) {
1974 		adminq->cq_vector = -1;
1975 		return result;
1976 	}
1977 	return nvme_create_io_queues(dev);
1978 }
1979 
1980 static void nvme_del_queue_end(struct request *req, blk_status_t error)
1981 {
1982 	struct nvme_queue *nvmeq = req->end_io_data;
1983 
1984 	blk_mq_free_request(req);
1985 	complete(&nvmeq->dev->ioq_wait);
1986 }
1987 
1988 static void nvme_del_cq_end(struct request *req, blk_status_t error)
1989 {
1990 	struct nvme_queue *nvmeq = req->end_io_data;
1991 
1992 	if (!error) {
1993 		unsigned long flags;
1994 
1995 		/*
1996 		 * We might be called with the AQ q_lock held
1997 		 * and the I/O queue q_lock should always
1998 		 * nest inside the AQ one.
1999 		 */
2000 		spin_lock_irqsave_nested(&nvmeq->q_lock, flags,
2001 					SINGLE_DEPTH_NESTING);
2002 		nvme_process_cq(nvmeq);
2003 		spin_unlock_irqrestore(&nvmeq->q_lock, flags);
2004 	}
2005 
2006 	nvme_del_queue_end(req, error);
2007 }
2008 
2009 static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
2010 {
2011 	struct request_queue *q = nvmeq->dev->ctrl.admin_q;
2012 	struct request *req;
2013 	struct nvme_command cmd;
2014 
2015 	memset(&cmd, 0, sizeof(cmd));
2016 	cmd.delete_queue.opcode = opcode;
2017 	cmd.delete_queue.qid = cpu_to_le16(nvmeq->qid);
2018 
2019 	req = nvme_alloc_request(q, &cmd, BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
2020 	if (IS_ERR(req))
2021 		return PTR_ERR(req);
2022 
2023 	req->timeout = ADMIN_TIMEOUT;
2024 	req->end_io_data = nvmeq;
2025 
2026 	blk_execute_rq_nowait(q, NULL, req, false,
2027 			opcode == nvme_admin_delete_cq ?
2028 				nvme_del_cq_end : nvme_del_queue_end);
2029 	return 0;
2030 }
2031 
2032 static void nvme_disable_io_queues(struct nvme_dev *dev)
2033 {
2034 	int pass, queues = dev->online_queues - 1;
2035 	unsigned long timeout;
2036 	u8 opcode = nvme_admin_delete_sq;
2037 
2038 	for (pass = 0; pass < 2; pass++) {
2039 		int sent = 0, i = queues;
2040 
2041 		reinit_completion(&dev->ioq_wait);
2042  retry:
2043 		timeout = ADMIN_TIMEOUT;
2044 		for (; i > 0; i--, sent++)
2045 			if (nvme_delete_queue(&dev->queues[i], opcode))
2046 				break;
2047 
2048 		while (sent--) {
2049 			timeout = wait_for_completion_io_timeout(&dev->ioq_wait, timeout);
2050 			if (timeout == 0)
2051 				return;
2052 			if (i)
2053 				goto retry;
2054 		}
2055 		opcode = nvme_admin_delete_cq;
2056 	}
2057 }
2058 
2059 /*
2060  * return error value only when tagset allocation failed
2061  */
2062 static int nvme_dev_add(struct nvme_dev *dev)
2063 {
2064 	int ret;
2065 
2066 	if (!dev->ctrl.tagset) {
2067 		dev->tagset.ops = &nvme_mq_ops;
2068 		dev->tagset.nr_hw_queues = dev->online_queues - 1;
2069 		dev->tagset.timeout = NVME_IO_TIMEOUT;
2070 		dev->tagset.numa_node = dev_to_node(dev->dev);
2071 		dev->tagset.queue_depth =
2072 				min_t(int, dev->q_depth, BLK_MQ_MAX_DEPTH) - 1;
2073 		dev->tagset.cmd_size = nvme_pci_cmd_size(dev, false);
2074 		if ((dev->ctrl.sgls & ((1 << 0) | (1 << 1))) && sgl_threshold) {
2075 			dev->tagset.cmd_size = max(dev->tagset.cmd_size,
2076 					nvme_pci_cmd_size(dev, true));
2077 		}
2078 		dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
2079 		dev->tagset.driver_data = dev;
2080 
2081 		ret = blk_mq_alloc_tag_set(&dev->tagset);
2082 		if (ret) {
2083 			dev_warn(dev->ctrl.device,
2084 				"IO queues tagset allocation failed %d\n", ret);
2085 			return ret;
2086 		}
2087 		dev->ctrl.tagset = &dev->tagset;
2088 
2089 		nvme_dbbuf_set(dev);
2090 	} else {
2091 		blk_mq_update_nr_hw_queues(&dev->tagset, dev->online_queues - 1);
2092 
2093 		/* Free previously allocated queues that are no longer usable */
2094 		nvme_free_queues(dev, dev->online_queues);
2095 	}
2096 
2097 	return 0;
2098 }
2099 
2100 static int nvme_pci_enable(struct nvme_dev *dev)
2101 {
2102 	int result = -ENOMEM;
2103 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2104 
2105 	if (pci_enable_device_mem(pdev))
2106 		return result;
2107 
2108 	pci_set_master(pdev);
2109 
2110 	if (dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(64)) &&
2111 	    dma_set_mask_and_coherent(dev->dev, DMA_BIT_MASK(32)))
2112 		goto disable;
2113 
2114 	if (readl(dev->bar + NVME_REG_CSTS) == -1) {
2115 		result = -ENODEV;
2116 		goto disable;
2117 	}
2118 
2119 	/*
2120 	 * Some devices and/or platforms don't advertise or work with INTx
2121 	 * interrupts. Pre-enable a single MSIX or MSI vec for setup. We'll
2122 	 * adjust this later.
2123 	 */
2124 	result = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
2125 	if (result < 0)
2126 		return result;
2127 
2128 	dev->ctrl.cap = lo_hi_readq(dev->bar + NVME_REG_CAP);
2129 
2130 	dev->q_depth = min_t(int, NVME_CAP_MQES(dev->ctrl.cap) + 1,
2131 				io_queue_depth);
2132 	dev->db_stride = 1 << NVME_CAP_STRIDE(dev->ctrl.cap);
2133 	dev->dbs = dev->bar + 4096;
2134 
2135 	/*
2136 	 * Temporary fix for the Apple controller found in the MacBook8,1 and
2137 	 * some MacBook7,1 to avoid controller resets and data loss.
2138 	 */
2139 	if (pdev->vendor == PCI_VENDOR_ID_APPLE && pdev->device == 0x2001) {
2140 		dev->q_depth = 2;
2141 		dev_warn(dev->ctrl.device, "detected Apple NVMe controller, "
2142 			"set queue depth=%u to work around controller resets\n",
2143 			dev->q_depth);
2144 	} else if (pdev->vendor == PCI_VENDOR_ID_SAMSUNG &&
2145 		   (pdev->device == 0xa821 || pdev->device == 0xa822) &&
2146 		   NVME_CAP_MQES(dev->ctrl.cap) == 0) {
2147 		dev->q_depth = 64;
2148 		dev_err(dev->ctrl.device, "detected PM1725 NVMe controller, "
2149                         "set queue depth=%u\n", dev->q_depth);
2150 	}
2151 
2152 	nvme_map_cmb(dev);
2153 
2154 	pci_enable_pcie_error_reporting(pdev);
2155 	pci_save_state(pdev);
2156 	return 0;
2157 
2158  disable:
2159 	pci_disable_device(pdev);
2160 	return result;
2161 }
2162 
2163 static void nvme_dev_unmap(struct nvme_dev *dev)
2164 {
2165 	if (dev->bar)
2166 		iounmap(dev->bar);
2167 	pci_release_mem_regions(to_pci_dev(dev->dev));
2168 }
2169 
2170 static void nvme_pci_disable(struct nvme_dev *dev)
2171 {
2172 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2173 
2174 	nvme_release_cmb(dev);
2175 	pci_free_irq_vectors(pdev);
2176 
2177 	if (pci_is_enabled(pdev)) {
2178 		pci_disable_pcie_error_reporting(pdev);
2179 		pci_disable_device(pdev);
2180 	}
2181 }
2182 
2183 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
2184 {
2185 	int i;
2186 	bool dead = true;
2187 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2188 
2189 	mutex_lock(&dev->shutdown_lock);
2190 	if (pci_is_enabled(pdev)) {
2191 		u32 csts = readl(dev->bar + NVME_REG_CSTS);
2192 
2193 		if (dev->ctrl.state == NVME_CTRL_LIVE ||
2194 		    dev->ctrl.state == NVME_CTRL_RESETTING)
2195 			nvme_start_freeze(&dev->ctrl);
2196 		dead = !!((csts & NVME_CSTS_CFS) || !(csts & NVME_CSTS_RDY) ||
2197 			pdev->error_state  != pci_channel_io_normal);
2198 	}
2199 
2200 	/*
2201 	 * Give the controller a chance to complete all entered requests if
2202 	 * doing a safe shutdown.
2203 	 */
2204 	if (!dead) {
2205 		if (shutdown)
2206 			nvme_wait_freeze_timeout(&dev->ctrl, NVME_IO_TIMEOUT);
2207 	}
2208 
2209 	nvme_stop_queues(&dev->ctrl);
2210 
2211 	if (!dead && dev->ctrl.queue_count > 0) {
2212 		/*
2213 		 * If the controller is still alive tell it to stop using the
2214 		 * host memory buffer.  In theory the shutdown / reset should
2215 		 * make sure that it doesn't access the host memoery anymore,
2216 		 * but I'd rather be safe than sorry..
2217 		 */
2218 		if (dev->host_mem_descs)
2219 			nvme_set_host_mem(dev, 0);
2220 		nvme_disable_io_queues(dev);
2221 		nvme_disable_admin_queue(dev, shutdown);
2222 	}
2223 	for (i = dev->ctrl.queue_count - 1; i >= 0; i--)
2224 		nvme_suspend_queue(&dev->queues[i]);
2225 
2226 	nvme_pci_disable(dev);
2227 
2228 	blk_mq_tagset_busy_iter(&dev->tagset, nvme_cancel_request, &dev->ctrl);
2229 	blk_mq_tagset_busy_iter(&dev->admin_tagset, nvme_cancel_request, &dev->ctrl);
2230 
2231 	/*
2232 	 * The driver will not be starting up queues again if shutting down so
2233 	 * must flush all entered requests to their failed completion to avoid
2234 	 * deadlocking blk-mq hot-cpu notifier.
2235 	 */
2236 	if (shutdown)
2237 		nvme_start_queues(&dev->ctrl);
2238 	mutex_unlock(&dev->shutdown_lock);
2239 }
2240 
2241 static int nvme_setup_prp_pools(struct nvme_dev *dev)
2242 {
2243 	dev->prp_page_pool = dma_pool_create("prp list page", dev->dev,
2244 						PAGE_SIZE, PAGE_SIZE, 0);
2245 	if (!dev->prp_page_pool)
2246 		return -ENOMEM;
2247 
2248 	/* Optimisation for I/Os between 4k and 128k */
2249 	dev->prp_small_pool = dma_pool_create("prp list 256", dev->dev,
2250 						256, 256, 0);
2251 	if (!dev->prp_small_pool) {
2252 		dma_pool_destroy(dev->prp_page_pool);
2253 		return -ENOMEM;
2254 	}
2255 	return 0;
2256 }
2257 
2258 static void nvme_release_prp_pools(struct nvme_dev *dev)
2259 {
2260 	dma_pool_destroy(dev->prp_page_pool);
2261 	dma_pool_destroy(dev->prp_small_pool);
2262 }
2263 
2264 static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
2265 {
2266 	struct nvme_dev *dev = to_nvme_dev(ctrl);
2267 
2268 	nvme_dbbuf_dma_free(dev);
2269 	put_device(dev->dev);
2270 	if (dev->tagset.tags)
2271 		blk_mq_free_tag_set(&dev->tagset);
2272 	if (dev->ctrl.admin_q)
2273 		blk_put_queue(dev->ctrl.admin_q);
2274 	kfree(dev->queues);
2275 	free_opal_dev(dev->ctrl.opal_dev);
2276 	kfree(dev);
2277 }
2278 
2279 static void nvme_remove_dead_ctrl(struct nvme_dev *dev, int status)
2280 {
2281 	dev_warn(dev->ctrl.device, "Removing after probe failure status: %d\n", status);
2282 
2283 	nvme_get_ctrl(&dev->ctrl);
2284 	nvme_dev_disable(dev, false);
2285 	if (!queue_work(nvme_wq, &dev->remove_work))
2286 		nvme_put_ctrl(&dev->ctrl);
2287 }
2288 
2289 static void nvme_reset_work(struct work_struct *work)
2290 {
2291 	struct nvme_dev *dev =
2292 		container_of(work, struct nvme_dev, ctrl.reset_work);
2293 	bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL);
2294 	int result = -ENODEV;
2295 	enum nvme_ctrl_state new_state = NVME_CTRL_LIVE;
2296 
2297 	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING))
2298 		goto out;
2299 
2300 	/*
2301 	 * If we're called to reset a live controller first shut it down before
2302 	 * moving on.
2303 	 */
2304 	if (dev->ctrl.ctrl_config & NVME_CC_ENABLE)
2305 		nvme_dev_disable(dev, false);
2306 
2307 	/*
2308 	 * Introduce CONNECTING state from nvme-fc/rdma transports to mark the
2309 	 * initializing procedure here.
2310 	 */
2311 	if (!nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_CONNECTING)) {
2312 		dev_warn(dev->ctrl.device,
2313 			"failed to mark controller CONNECTING\n");
2314 		goto out;
2315 	}
2316 
2317 	result = nvme_pci_enable(dev);
2318 	if (result)
2319 		goto out;
2320 
2321 	result = nvme_pci_configure_admin_queue(dev);
2322 	if (result)
2323 		goto out;
2324 
2325 	result = nvme_alloc_admin_tags(dev);
2326 	if (result)
2327 		goto out;
2328 
2329 	result = nvme_init_identify(&dev->ctrl);
2330 	if (result)
2331 		goto out;
2332 
2333 	if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
2334 		if (!dev->ctrl.opal_dev)
2335 			dev->ctrl.opal_dev =
2336 				init_opal_dev(&dev->ctrl, &nvme_sec_submit);
2337 		else if (was_suspend)
2338 			opal_unlock_from_suspend(dev->ctrl.opal_dev);
2339 	} else {
2340 		free_opal_dev(dev->ctrl.opal_dev);
2341 		dev->ctrl.opal_dev = NULL;
2342 	}
2343 
2344 	if (dev->ctrl.oacs & NVME_CTRL_OACS_DBBUF_SUPP) {
2345 		result = nvme_dbbuf_dma_alloc(dev);
2346 		if (result)
2347 			dev_warn(dev->dev,
2348 				 "unable to allocate dma for dbbuf\n");
2349 	}
2350 
2351 	if (dev->ctrl.hmpre) {
2352 		result = nvme_setup_host_mem(dev);
2353 		if (result < 0)
2354 			goto out;
2355 	}
2356 
2357 	result = nvme_setup_io_queues(dev);
2358 	if (result)
2359 		goto out;
2360 
2361 	/*
2362 	 * Keep the controller around but remove all namespaces if we don't have
2363 	 * any working I/O queue.
2364 	 */
2365 	if (dev->online_queues < 2) {
2366 		dev_warn(dev->ctrl.device, "IO queues not created\n");
2367 		nvme_kill_queues(&dev->ctrl);
2368 		nvme_remove_namespaces(&dev->ctrl);
2369 		new_state = NVME_CTRL_ADMIN_ONLY;
2370 	} else {
2371 		nvme_start_queues(&dev->ctrl);
2372 		nvme_wait_freeze(&dev->ctrl);
2373 		/* hit this only when allocate tagset fails */
2374 		if (nvme_dev_add(dev))
2375 			new_state = NVME_CTRL_ADMIN_ONLY;
2376 		nvme_unfreeze(&dev->ctrl);
2377 	}
2378 
2379 	/*
2380 	 * If only admin queue live, keep it to do further investigation or
2381 	 * recovery.
2382 	 */
2383 	if (!nvme_change_ctrl_state(&dev->ctrl, new_state)) {
2384 		dev_warn(dev->ctrl.device,
2385 			"failed to mark controller state %d\n", new_state);
2386 		goto out;
2387 	}
2388 
2389 	nvme_start_ctrl(&dev->ctrl);
2390 	return;
2391 
2392  out:
2393 	nvme_remove_dead_ctrl(dev, result);
2394 }
2395 
2396 static void nvme_remove_dead_ctrl_work(struct work_struct *work)
2397 {
2398 	struct nvme_dev *dev = container_of(work, struct nvme_dev, remove_work);
2399 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2400 
2401 	nvme_kill_queues(&dev->ctrl);
2402 	if (pci_get_drvdata(pdev))
2403 		device_release_driver(&pdev->dev);
2404 	nvme_put_ctrl(&dev->ctrl);
2405 }
2406 
2407 static int nvme_pci_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val)
2408 {
2409 	*val = readl(to_nvme_dev(ctrl)->bar + off);
2410 	return 0;
2411 }
2412 
2413 static int nvme_pci_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val)
2414 {
2415 	writel(val, to_nvme_dev(ctrl)->bar + off);
2416 	return 0;
2417 }
2418 
2419 static int nvme_pci_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val)
2420 {
2421 	*val = readq(to_nvme_dev(ctrl)->bar + off);
2422 	return 0;
2423 }
2424 
2425 static int nvme_pci_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
2426 {
2427 	struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev);
2428 
2429 	return snprintf(buf, size, "%s", dev_name(&pdev->dev));
2430 }
2431 
2432 static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
2433 	.name			= "pcie",
2434 	.module			= THIS_MODULE,
2435 	.flags			= NVME_F_METADATA_SUPPORTED,
2436 	.reg_read32		= nvme_pci_reg_read32,
2437 	.reg_write32		= nvme_pci_reg_write32,
2438 	.reg_read64		= nvme_pci_reg_read64,
2439 	.free_ctrl		= nvme_pci_free_ctrl,
2440 	.submit_async_event	= nvme_pci_submit_async_event,
2441 	.get_address		= nvme_pci_get_address,
2442 };
2443 
2444 static int nvme_dev_map(struct nvme_dev *dev)
2445 {
2446 	struct pci_dev *pdev = to_pci_dev(dev->dev);
2447 
2448 	if (pci_request_mem_regions(pdev, "nvme"))
2449 		return -ENODEV;
2450 
2451 	if (nvme_remap_bar(dev, NVME_REG_DBS + 4096))
2452 		goto release;
2453 
2454 	return 0;
2455   release:
2456 	pci_release_mem_regions(pdev);
2457 	return -ENODEV;
2458 }
2459 
2460 static unsigned long check_vendor_combination_bug(struct pci_dev *pdev)
2461 {
2462 	if (pdev->vendor == 0x144d && pdev->device == 0xa802) {
2463 		/*
2464 		 * Several Samsung devices seem to drop off the PCIe bus
2465 		 * randomly when APST is on and uses the deepest sleep state.
2466 		 * This has been observed on a Samsung "SM951 NVMe SAMSUNG
2467 		 * 256GB", a "PM951 NVMe SAMSUNG 512GB", and a "Samsung SSD
2468 		 * 950 PRO 256GB", but it seems to be restricted to two Dell
2469 		 * laptops.
2470 		 */
2471 		if (dmi_match(DMI_SYS_VENDOR, "Dell Inc.") &&
2472 		    (dmi_match(DMI_PRODUCT_NAME, "XPS 15 9550") ||
2473 		     dmi_match(DMI_PRODUCT_NAME, "Precision 5510")))
2474 			return NVME_QUIRK_NO_DEEPEST_PS;
2475 	} else if (pdev->vendor == 0x144d && pdev->device == 0xa804) {
2476 		/*
2477 		 * Samsung SSD 960 EVO drops off the PCIe bus after system
2478 		 * suspend on a Ryzen board, ASUS PRIME B350M-A, as well as
2479 		 * within few minutes after bootup on a Coffee Lake board -
2480 		 * ASUS PRIME Z370-A
2481 		 */
2482 		if (dmi_match(DMI_BOARD_VENDOR, "ASUSTeK COMPUTER INC.") &&
2483 		    (dmi_match(DMI_BOARD_NAME, "PRIME B350M-A") ||
2484 		     dmi_match(DMI_BOARD_NAME, "PRIME Z370-A")))
2485 			return NVME_QUIRK_NO_APST;
2486 	}
2487 
2488 	return 0;
2489 }
2490 
2491 static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
2492 {
2493 	int node, result = -ENOMEM;
2494 	struct nvme_dev *dev;
2495 	unsigned long quirks = id->driver_data;
2496 
2497 	node = dev_to_node(&pdev->dev);
2498 	if (node == NUMA_NO_NODE)
2499 		set_dev_node(&pdev->dev, first_memory_node);
2500 
2501 	dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
2502 	if (!dev)
2503 		return -ENOMEM;
2504 
2505 	dev->queues = kcalloc_node(num_possible_cpus() + 1,
2506 			sizeof(struct nvme_queue), GFP_KERNEL, node);
2507 	if (!dev->queues)
2508 		goto free;
2509 
2510 	dev->dev = get_device(&pdev->dev);
2511 	pci_set_drvdata(pdev, dev);
2512 
2513 	result = nvme_dev_map(dev);
2514 	if (result)
2515 		goto put_pci;
2516 
2517 	INIT_WORK(&dev->ctrl.reset_work, nvme_reset_work);
2518 	INIT_WORK(&dev->remove_work, nvme_remove_dead_ctrl_work);
2519 	mutex_init(&dev->shutdown_lock);
2520 	init_completion(&dev->ioq_wait);
2521 
2522 	result = nvme_setup_prp_pools(dev);
2523 	if (result)
2524 		goto unmap;
2525 
2526 	quirks |= check_vendor_combination_bug(pdev);
2527 
2528 	result = nvme_init_ctrl(&dev->ctrl, &pdev->dev, &nvme_pci_ctrl_ops,
2529 			quirks);
2530 	if (result)
2531 		goto release_pools;
2532 
2533 	dev_info(dev->ctrl.device, "pci function %s\n", dev_name(&pdev->dev));
2534 
2535 	nvme_reset_ctrl(&dev->ctrl);
2536 
2537 	return 0;
2538 
2539  release_pools:
2540 	nvme_release_prp_pools(dev);
2541  unmap:
2542 	nvme_dev_unmap(dev);
2543  put_pci:
2544 	put_device(dev->dev);
2545  free:
2546 	kfree(dev->queues);
2547 	kfree(dev);
2548 	return result;
2549 }
2550 
2551 static void nvme_reset_prepare(struct pci_dev *pdev)
2552 {
2553 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2554 	nvme_dev_disable(dev, false);
2555 }
2556 
2557 static void nvme_reset_done(struct pci_dev *pdev)
2558 {
2559 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2560 	nvme_reset_ctrl_sync(&dev->ctrl);
2561 }
2562 
2563 static void nvme_shutdown(struct pci_dev *pdev)
2564 {
2565 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2566 	nvme_dev_disable(dev, true);
2567 }
2568 
2569 /*
2570  * The driver's remove may be called on a device in a partially initialized
2571  * state. This function must not have any dependencies on the device state in
2572  * order to proceed.
2573  */
2574 static void nvme_remove(struct pci_dev *pdev)
2575 {
2576 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2577 
2578 	nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING);
2579 
2580 	cancel_work_sync(&dev->ctrl.reset_work);
2581 	pci_set_drvdata(pdev, NULL);
2582 
2583 	if (!pci_device_is_present(pdev)) {
2584 		nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DEAD);
2585 		nvme_dev_disable(dev, false);
2586 	}
2587 
2588 	flush_work(&dev->ctrl.reset_work);
2589 	nvme_stop_ctrl(&dev->ctrl);
2590 	nvme_remove_namespaces(&dev->ctrl);
2591 	nvme_dev_disable(dev, true);
2592 	nvme_free_host_mem(dev);
2593 	nvme_dev_remove_admin(dev);
2594 	nvme_free_queues(dev, 0);
2595 	nvme_uninit_ctrl(&dev->ctrl);
2596 	nvme_release_prp_pools(dev);
2597 	nvme_dev_unmap(dev);
2598 	nvme_put_ctrl(&dev->ctrl);
2599 }
2600 
2601 static int nvme_pci_sriov_configure(struct pci_dev *pdev, int numvfs)
2602 {
2603 	int ret = 0;
2604 
2605 	if (numvfs == 0) {
2606 		if (pci_vfs_assigned(pdev)) {
2607 			dev_warn(&pdev->dev,
2608 				"Cannot disable SR-IOV VFs while assigned\n");
2609 			return -EPERM;
2610 		}
2611 		pci_disable_sriov(pdev);
2612 		return 0;
2613 	}
2614 
2615 	ret = pci_enable_sriov(pdev, numvfs);
2616 	return ret ? ret : numvfs;
2617 }
2618 
2619 #ifdef CONFIG_PM_SLEEP
2620 static int nvme_suspend(struct device *dev)
2621 {
2622 	struct pci_dev *pdev = to_pci_dev(dev);
2623 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2624 
2625 	nvme_dev_disable(ndev, true);
2626 	return 0;
2627 }
2628 
2629 static int nvme_resume(struct device *dev)
2630 {
2631 	struct pci_dev *pdev = to_pci_dev(dev);
2632 	struct nvme_dev *ndev = pci_get_drvdata(pdev);
2633 
2634 	nvme_reset_ctrl(&ndev->ctrl);
2635 	return 0;
2636 }
2637 #endif
2638 
2639 static SIMPLE_DEV_PM_OPS(nvme_dev_pm_ops, nvme_suspend, nvme_resume);
2640 
2641 static pci_ers_result_t nvme_error_detected(struct pci_dev *pdev,
2642 						pci_channel_state_t state)
2643 {
2644 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2645 
2646 	/*
2647 	 * A frozen channel requires a reset. When detected, this method will
2648 	 * shutdown the controller to quiesce. The controller will be restarted
2649 	 * after the slot reset through driver's slot_reset callback.
2650 	 */
2651 	switch (state) {
2652 	case pci_channel_io_normal:
2653 		return PCI_ERS_RESULT_CAN_RECOVER;
2654 	case pci_channel_io_frozen:
2655 		dev_warn(dev->ctrl.device,
2656 			"frozen state error detected, reset controller\n");
2657 		nvme_dev_disable(dev, false);
2658 		return PCI_ERS_RESULT_NEED_RESET;
2659 	case pci_channel_io_perm_failure:
2660 		dev_warn(dev->ctrl.device,
2661 			"failure state error detected, request disconnect\n");
2662 		return PCI_ERS_RESULT_DISCONNECT;
2663 	}
2664 	return PCI_ERS_RESULT_NEED_RESET;
2665 }
2666 
2667 static pci_ers_result_t nvme_slot_reset(struct pci_dev *pdev)
2668 {
2669 	struct nvme_dev *dev = pci_get_drvdata(pdev);
2670 
2671 	dev_info(dev->ctrl.device, "restart after slot reset\n");
2672 	pci_restore_state(pdev);
2673 	nvme_reset_ctrl(&dev->ctrl);
2674 	return PCI_ERS_RESULT_RECOVERED;
2675 }
2676 
2677 static void nvme_error_resume(struct pci_dev *pdev)
2678 {
2679 	pci_cleanup_aer_uncorrect_error_status(pdev);
2680 }
2681 
2682 static const struct pci_error_handlers nvme_err_handler = {
2683 	.error_detected	= nvme_error_detected,
2684 	.slot_reset	= nvme_slot_reset,
2685 	.resume		= nvme_error_resume,
2686 	.reset_prepare	= nvme_reset_prepare,
2687 	.reset_done	= nvme_reset_done,
2688 };
2689 
2690 static const struct pci_device_id nvme_id_table[] = {
2691 	{ PCI_VDEVICE(INTEL, 0x0953),
2692 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2693 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2694 	{ PCI_VDEVICE(INTEL, 0x0a53),
2695 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2696 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2697 	{ PCI_VDEVICE(INTEL, 0x0a54),
2698 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2699 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2700 	{ PCI_VDEVICE(INTEL, 0x0a55),
2701 		.driver_data = NVME_QUIRK_STRIPE_SIZE |
2702 				NVME_QUIRK_DEALLOCATE_ZEROES, },
2703 	{ PCI_VDEVICE(INTEL, 0xf1a5),	/* Intel 600P/P3100 */
2704 		.driver_data = NVME_QUIRK_NO_DEEPEST_PS },
2705 	{ PCI_VDEVICE(INTEL, 0x5845),	/* Qemu emulated controller */
2706 		.driver_data = NVME_QUIRK_IDENTIFY_CNS, },
2707 	{ PCI_DEVICE(0x1c58, 0x0003),	/* HGST adapter */
2708 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2709 	{ PCI_DEVICE(0x1c58, 0x0023),	/* WDC SN200 adapter */
2710 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2711 	{ PCI_DEVICE(0x1c5f, 0x0540),	/* Memblaze Pblaze4 adapter */
2712 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2713 	{ PCI_DEVICE(0x144d, 0xa821),   /* Samsung PM1725 */
2714 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2715 	{ PCI_DEVICE(0x144d, 0xa822),   /* Samsung PM1725a */
2716 		.driver_data = NVME_QUIRK_DELAY_BEFORE_CHK_RDY, },
2717 	{ PCI_DEVICE(0x1d1d, 0x1f1f),	/* LighNVM qemu device */
2718 		.driver_data = NVME_QUIRK_LIGHTNVM, },
2719 	{ PCI_DEVICE(0x1d1d, 0x2807),	/* CNEX WL */
2720 		.driver_data = NVME_QUIRK_LIGHTNVM, },
2721 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
2722 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
2723 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2003) },
2724 	{ 0, }
2725 };
2726 MODULE_DEVICE_TABLE(pci, nvme_id_table);
2727 
2728 static struct pci_driver nvme_driver = {
2729 	.name		= "nvme",
2730 	.id_table	= nvme_id_table,
2731 	.probe		= nvme_probe,
2732 	.remove		= nvme_remove,
2733 	.shutdown	= nvme_shutdown,
2734 	.driver		= {
2735 		.pm	= &nvme_dev_pm_ops,
2736 	},
2737 	.sriov_configure = nvme_pci_sriov_configure,
2738 	.err_handler	= &nvme_err_handler,
2739 };
2740 
2741 static int __init nvme_init(void)
2742 {
2743 	return pci_register_driver(&nvme_driver);
2744 }
2745 
2746 static void __exit nvme_exit(void)
2747 {
2748 	pci_unregister_driver(&nvme_driver);
2749 	flush_workqueue(nvme_wq);
2750 	_nvme_check_size();
2751 }
2752 
2753 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
2754 MODULE_LICENSE("GPL");
2755 MODULE_VERSION("1.0");
2756 module_init(nvme_init);
2757 module_exit(nvme_exit);
2758