nvme-core.c revision eca18b2394a9387feeaf14cd884ddddd7a809d19
1/*
2 * NVM Express device driver
3 * Copyright (c) 2011, 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 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19#include <linux/nvme.h>
20#include <linux/bio.h>
21#include <linux/bitops.h>
22#include <linux/blkdev.h>
23#include <linux/delay.h>
24#include <linux/errno.h>
25#include <linux/fs.h>
26#include <linux/genhd.h>
27#include <linux/idr.h>
28#include <linux/init.h>
29#include <linux/interrupt.h>
30#include <linux/io.h>
31#include <linux/kdev_t.h>
32#include <linux/kthread.h>
33#include <linux/kernel.h>
34#include <linux/mm.h>
35#include <linux/module.h>
36#include <linux/moduleparam.h>
37#include <linux/pci.h>
38#include <linux/poison.h>
39#include <linux/sched.h>
40#include <linux/slab.h>
41#include <linux/types.h>
42#include <linux/version.h>
43
44#define NVME_Q_DEPTH 1024
45#define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
46#define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
47#define NVME_MINORS 64
48#define IO_TIMEOUT	(5 * HZ)
49#define ADMIN_TIMEOUT	(60 * HZ)
50
51static int nvme_major;
52module_param(nvme_major, int, 0);
53
54static int use_threaded_interrupts;
55module_param(use_threaded_interrupts, int, 0);
56
57static DEFINE_SPINLOCK(dev_list_lock);
58static LIST_HEAD(dev_list);
59static struct task_struct *nvme_thread;
60
61/*
62 * Represents an NVM Express device.  Each nvme_dev is a PCI function.
63 */
64struct nvme_dev {
65	struct list_head node;
66	struct nvme_queue **queues;
67	u32 __iomem *dbs;
68	struct pci_dev *pci_dev;
69	struct dma_pool *prp_page_pool;
70	struct dma_pool *prp_small_pool;
71	int instance;
72	int queue_count;
73	int db_stride;
74	u32 ctrl_config;
75	struct msix_entry *entry;
76	struct nvme_bar __iomem *bar;
77	struct list_head namespaces;
78	char serial[20];
79	char model[40];
80	char firmware_rev[8];
81};
82
83/*
84 * An NVM Express namespace is equivalent to a SCSI LUN
85 */
86struct nvme_ns {
87	struct list_head list;
88
89	struct nvme_dev *dev;
90	struct request_queue *queue;
91	struct gendisk *disk;
92
93	int ns_id;
94	int lba_shift;
95};
96
97/*
98 * An NVM Express queue.  Each device has at least two (one for admin
99 * commands and one for I/O commands).
100 */
101struct nvme_queue {
102	struct device *q_dmadev;
103	struct nvme_dev *dev;
104	spinlock_t q_lock;
105	struct nvme_command *sq_cmds;
106	volatile struct nvme_completion *cqes;
107	dma_addr_t sq_dma_addr;
108	dma_addr_t cq_dma_addr;
109	wait_queue_head_t sq_full;
110	wait_queue_t sq_cong_wait;
111	struct bio_list sq_cong;
112	u32 __iomem *q_db;
113	u16 q_depth;
114	u16 cq_vector;
115	u16 sq_head;
116	u16 sq_tail;
117	u16 cq_head;
118	u16 cq_phase;
119	unsigned long cmdid_data[];
120};
121
122/*
123 * Check we didin't inadvertently grow the command struct
124 */
125static inline void _nvme_check_size(void)
126{
127	BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
128	BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
129	BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
130	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
131	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
132	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
133	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != 4096);
134	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != 4096);
135	BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
136}
137
138typedef void (*nvme_completion_fn)(struct nvme_dev *, void *,
139						struct nvme_completion *);
140
141struct nvme_cmd_info {
142	nvme_completion_fn fn;
143	void *ctx;
144	unsigned long timeout;
145};
146
147static struct nvme_cmd_info *nvme_cmd_info(struct nvme_queue *nvmeq)
148{
149	return (void *)&nvmeq->cmdid_data[BITS_TO_LONGS(nvmeq->q_depth)];
150}
151
152/**
153 * alloc_cmdid() - Allocate a Command ID
154 * @nvmeq: The queue that will be used for this command
155 * @ctx: A pointer that will be passed to the handler
156 * @handler: The function to call on completion
157 *
158 * Allocate a Command ID for a queue.  The data passed in will
159 * be passed to the completion handler.  This is implemented by using
160 * the bottom two bits of the ctx pointer to store the handler ID.
161 * Passing in a pointer that's not 4-byte aligned will cause a BUG.
162 * We can change this if it becomes a problem.
163 *
164 * May be called with local interrupts disabled and the q_lock held,
165 * or with interrupts enabled and no locks held.
166 */
167static int alloc_cmdid(struct nvme_queue *nvmeq, void *ctx,
168				nvme_completion_fn handler, unsigned timeout)
169{
170	int depth = nvmeq->q_depth - 1;
171	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
172	int cmdid;
173
174	do {
175		cmdid = find_first_zero_bit(nvmeq->cmdid_data, depth);
176		if (cmdid >= depth)
177			return -EBUSY;
178	} while (test_and_set_bit(cmdid, nvmeq->cmdid_data));
179
180	info[cmdid].fn = handler;
181	info[cmdid].ctx = ctx;
182	info[cmdid].timeout = jiffies + timeout;
183	return cmdid;
184}
185
186static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
187				nvme_completion_fn handler, unsigned timeout)
188{
189	int cmdid;
190	wait_event_killable(nvmeq->sq_full,
191		(cmdid = alloc_cmdid(nvmeq, ctx, handler, timeout)) >= 0);
192	return (cmdid < 0) ? -EINTR : cmdid;
193}
194
195/* Special values must be less than 0x1000 */
196#define CMD_CTX_BASE		((void *)POISON_POINTER_DELTA)
197#define CMD_CTX_CANCELLED	(0x30C + CMD_CTX_BASE)
198#define CMD_CTX_COMPLETED	(0x310 + CMD_CTX_BASE)
199#define CMD_CTX_INVALID		(0x314 + CMD_CTX_BASE)
200#define CMD_CTX_FLUSH		(0x318 + CMD_CTX_BASE)
201
202static void special_completion(struct nvme_dev *dev, void *ctx,
203						struct nvme_completion *cqe)
204{
205	if (ctx == CMD_CTX_CANCELLED)
206		return;
207	if (ctx == CMD_CTX_FLUSH)
208		return;
209	if (ctx == CMD_CTX_COMPLETED) {
210		dev_warn(&dev->pci_dev->dev,
211				"completed id %d twice on queue %d\n",
212				cqe->command_id, le16_to_cpup(&cqe->sq_id));
213		return;
214	}
215	if (ctx == CMD_CTX_INVALID) {
216		dev_warn(&dev->pci_dev->dev,
217				"invalid id %d completed on queue %d\n",
218				cqe->command_id, le16_to_cpup(&cqe->sq_id));
219		return;
220	}
221
222	dev_warn(&dev->pci_dev->dev, "Unknown special completion %p\n", ctx);
223}
224
225/*
226 * Called with local interrupts disabled and the q_lock held.  May not sleep.
227 */
228static void *free_cmdid(struct nvme_queue *nvmeq, int cmdid,
229						nvme_completion_fn *fn)
230{
231	void *ctx;
232	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
233
234	if (cmdid >= nvmeq->q_depth) {
235		*fn = special_completion;
236		return CMD_CTX_INVALID;
237	}
238	*fn = info[cmdid].fn;
239	ctx = info[cmdid].ctx;
240	info[cmdid].fn = special_completion;
241	info[cmdid].ctx = CMD_CTX_COMPLETED;
242	clear_bit(cmdid, nvmeq->cmdid_data);
243	wake_up(&nvmeq->sq_full);
244	return ctx;
245}
246
247static void *cancel_cmdid(struct nvme_queue *nvmeq, int cmdid,
248						nvme_completion_fn *fn)
249{
250	void *ctx;
251	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
252	if (fn)
253		*fn = info[cmdid].fn;
254	ctx = info[cmdid].ctx;
255	info[cmdid].fn = special_completion;
256	info[cmdid].ctx = CMD_CTX_CANCELLED;
257	return ctx;
258}
259
260static struct nvme_queue *get_nvmeq(struct nvme_dev *dev)
261{
262	return dev->queues[get_cpu() + 1];
263}
264
265static void put_nvmeq(struct nvme_queue *nvmeq)
266{
267	put_cpu();
268}
269
270/**
271 * nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
272 * @nvmeq: The queue to use
273 * @cmd: The command to send
274 *
275 * Safe to use from interrupt context
276 */
277static int nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
278{
279	unsigned long flags;
280	u16 tail;
281	spin_lock_irqsave(&nvmeq->q_lock, flags);
282	tail = nvmeq->sq_tail;
283	memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
284	if (++tail == nvmeq->q_depth)
285		tail = 0;
286	writel(tail, nvmeq->q_db);
287	nvmeq->sq_tail = tail;
288	spin_unlock_irqrestore(&nvmeq->q_lock, flags);
289
290	return 0;
291}
292
293/*
294 * The nvme_iod describes the data in an I/O, including the list of PRP
295 * entries.  You can't see it in this data structure because C doesn't let
296 * me express that.  Use nvme_alloc_iod to ensure there's enough space
297 * allocated to store the PRP list.
298 */
299struct nvme_iod {
300	void *private;		/* For the use of the submitter of the I/O */
301	int npages;		/* In the PRP list. 0 means small pool in use */
302	int offset;		/* Of PRP list */
303	int nents;		/* Used in scatterlist */
304	int length;		/* Of data, in bytes */
305	dma_addr_t first_dma;
306	struct scatterlist sg[0];
307};
308
309static __le64 **iod_list(struct nvme_iod *iod)
310{
311	return ((void *)iod) + iod->offset;
312}
313
314/*
315 * Will slightly overestimate the number of pages needed.  This is OK
316 * as it only leads to a small amount of wasted memory for the lifetime of
317 * the I/O.
318 */
319static int nvme_npages(unsigned size)
320{
321	unsigned nprps = DIV_ROUND_UP(size + PAGE_SIZE, PAGE_SIZE);
322	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
323}
324
325static struct nvme_iod *
326nvme_alloc_iod(unsigned nseg, unsigned nbytes, gfp_t gfp)
327{
328	struct nvme_iod *iod = kmalloc(sizeof(struct nvme_iod) +
329				sizeof(__le64 *) * nvme_npages(nbytes) +
330				sizeof(struct scatterlist) * nseg, gfp);
331
332	if (iod) {
333		iod->offset = offsetof(struct nvme_iod, sg[nseg]);
334		iod->npages = -1;
335		iod->length = nbytes;
336	}
337
338	return iod;
339}
340
341static void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod)
342{
343	const int last_prp = PAGE_SIZE / 8 - 1;
344	int i;
345	__le64 **list = iod_list(iod);
346	dma_addr_t prp_dma = iod->first_dma;
347
348	if (iod->npages == 0)
349		dma_pool_free(dev->prp_small_pool, list[0], prp_dma);
350	for (i = 0; i < iod->npages; i++) {
351		__le64 *prp_list = list[i];
352		dma_addr_t next_prp_dma = le64_to_cpu(prp_list[last_prp]);
353		dma_pool_free(dev->prp_page_pool, prp_list, prp_dma);
354		prp_dma = next_prp_dma;
355	}
356	kfree(iod);
357}
358
359static void requeue_bio(struct nvme_dev *dev, struct bio *bio)
360{
361	struct nvme_queue *nvmeq = get_nvmeq(dev);
362	if (bio_list_empty(&nvmeq->sq_cong))
363		add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
364	bio_list_add(&nvmeq->sq_cong, bio);
365	put_nvmeq(nvmeq);
366	wake_up_process(nvme_thread);
367}
368
369static void bio_completion(struct nvme_dev *dev, void *ctx,
370						struct nvme_completion *cqe)
371{
372	struct nvme_iod *iod = ctx;
373	struct bio *bio = iod->private;
374	u16 status = le16_to_cpup(&cqe->status) >> 1;
375
376	dma_unmap_sg(&dev->pci_dev->dev, iod->sg, iod->nents,
377			bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
378	nvme_free_iod(dev, iod);
379	if (status) {
380		bio_endio(bio, -EIO);
381	} else if (bio->bi_vcnt > bio->bi_idx) {
382		requeue_bio(dev, bio);
383	} else {
384		bio_endio(bio, 0);
385	}
386}
387
388/* length is in bytes.  gfp flags indicates whether we may sleep. */
389static int nvme_setup_prps(struct nvme_dev *dev,
390			struct nvme_common_command *cmd, struct nvme_iod *iod,
391			int total_len, gfp_t gfp)
392{
393	struct dma_pool *pool;
394	int length = total_len;
395	struct scatterlist *sg = iod->sg;
396	int dma_len = sg_dma_len(sg);
397	u64 dma_addr = sg_dma_address(sg);
398	int offset = offset_in_page(dma_addr);
399	__le64 *prp_list;
400	__le64 **list = iod_list(iod);
401	dma_addr_t prp_dma;
402	int nprps, i;
403
404	cmd->prp1 = cpu_to_le64(dma_addr);
405	length -= (PAGE_SIZE - offset);
406	if (length <= 0)
407		return total_len;
408
409	dma_len -= (PAGE_SIZE - offset);
410	if (dma_len) {
411		dma_addr += (PAGE_SIZE - offset);
412	} else {
413		sg = sg_next(sg);
414		dma_addr = sg_dma_address(sg);
415		dma_len = sg_dma_len(sg);
416	}
417
418	if (length <= PAGE_SIZE) {
419		cmd->prp2 = cpu_to_le64(dma_addr);
420		return total_len;
421	}
422
423	nprps = DIV_ROUND_UP(length, PAGE_SIZE);
424	if (nprps <= (256 / 8)) {
425		pool = dev->prp_small_pool;
426		iod->npages = 0;
427	} else {
428		pool = dev->prp_page_pool;
429		iod->npages = 1;
430	}
431
432	prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
433	if (!prp_list) {
434		cmd->prp2 = cpu_to_le64(dma_addr);
435		iod->npages = -1;
436		return (total_len - length) + PAGE_SIZE;
437	}
438	list[0] = prp_list;
439	iod->first_dma = prp_dma;
440	cmd->prp2 = cpu_to_le64(prp_dma);
441	i = 0;
442	for (;;) {
443		if (i == PAGE_SIZE / 8) {
444			__le64 *old_prp_list = prp_list;
445			prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
446			if (!prp_list)
447				return total_len - length;
448			list[iod->npages++] = prp_list;
449			prp_list[0] = old_prp_list[i - 1];
450			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
451			i = 1;
452		}
453		prp_list[i++] = cpu_to_le64(dma_addr);
454		dma_len -= PAGE_SIZE;
455		dma_addr += PAGE_SIZE;
456		length -= PAGE_SIZE;
457		if (length <= 0)
458			break;
459		if (dma_len > 0)
460			continue;
461		BUG_ON(dma_len < 0);
462		sg = sg_next(sg);
463		dma_addr = sg_dma_address(sg);
464		dma_len = sg_dma_len(sg);
465	}
466
467	return total_len;
468}
469
470/* NVMe scatterlists require no holes in the virtual address */
471#define BIOVEC_NOT_VIRT_MERGEABLE(vec1, vec2)	((vec2)->bv_offset || \
472			(((vec1)->bv_offset + (vec1)->bv_len) % PAGE_SIZE))
473
474static int nvme_map_bio(struct device *dev, struct nvme_iod *iod,
475		struct bio *bio, enum dma_data_direction dma_dir, int psegs)
476{
477	struct bio_vec *bvec, *bvprv = NULL;
478	struct scatterlist *sg = NULL;
479	int i, old_idx, length = 0, nsegs = 0;
480
481	sg_init_table(iod->sg, psegs);
482	old_idx = bio->bi_idx;
483	bio_for_each_segment(bvec, bio, i) {
484		if (bvprv && BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) {
485			sg->length += bvec->bv_len;
486		} else {
487			if (bvprv && BIOVEC_NOT_VIRT_MERGEABLE(bvprv, bvec))
488				break;
489			sg = sg ? sg + 1 : iod->sg;
490			sg_set_page(sg, bvec->bv_page, bvec->bv_len,
491							bvec->bv_offset);
492			nsegs++;
493		}
494		length += bvec->bv_len;
495		bvprv = bvec;
496	}
497	bio->bi_idx = i;
498	iod->nents = nsegs;
499	sg_mark_end(sg);
500	if (dma_map_sg(dev, iod->sg, iod->nents, dma_dir) == 0) {
501		bio->bi_idx = old_idx;
502		return -ENOMEM;
503	}
504	return length;
505}
506
507static int nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
508								int cmdid)
509{
510	struct nvme_command *cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
511
512	memset(cmnd, 0, sizeof(*cmnd));
513	cmnd->common.opcode = nvme_cmd_flush;
514	cmnd->common.command_id = cmdid;
515	cmnd->common.nsid = cpu_to_le32(ns->ns_id);
516
517	if (++nvmeq->sq_tail == nvmeq->q_depth)
518		nvmeq->sq_tail = 0;
519	writel(nvmeq->sq_tail, nvmeq->q_db);
520
521	return 0;
522}
523
524static int nvme_submit_flush_data(struct nvme_queue *nvmeq, struct nvme_ns *ns)
525{
526	int cmdid = alloc_cmdid(nvmeq, (void *)CMD_CTX_FLUSH,
527						special_completion, IO_TIMEOUT);
528	if (unlikely(cmdid < 0))
529		return cmdid;
530
531	return nvme_submit_flush(nvmeq, ns, cmdid);
532}
533
534/*
535 * Called with local interrupts disabled and the q_lock held.  May not sleep.
536 */
537static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
538								struct bio *bio)
539{
540	struct nvme_command *cmnd;
541	struct nvme_iod *iod;
542	enum dma_data_direction dma_dir;
543	int cmdid, length, result = -ENOMEM;
544	u16 control;
545	u32 dsmgmt;
546	int psegs = bio_phys_segments(ns->queue, bio);
547
548	if ((bio->bi_rw & REQ_FLUSH) && psegs) {
549		result = nvme_submit_flush_data(nvmeq, ns);
550		if (result)
551			return result;
552	}
553
554	iod = nvme_alloc_iod(psegs, bio->bi_size, GFP_ATOMIC);
555	if (!iod)
556		goto nomem;
557	iod->private = bio;
558
559	result = -EBUSY;
560	cmdid = alloc_cmdid(nvmeq, iod, bio_completion, IO_TIMEOUT);
561	if (unlikely(cmdid < 0))
562		goto free_iod;
563
564	if ((bio->bi_rw & REQ_FLUSH) && !psegs)
565		return nvme_submit_flush(nvmeq, ns, cmdid);
566
567	control = 0;
568	if (bio->bi_rw & REQ_FUA)
569		control |= NVME_RW_FUA;
570	if (bio->bi_rw & (REQ_FAILFAST_DEV | REQ_RAHEAD))
571		control |= NVME_RW_LR;
572
573	dsmgmt = 0;
574	if (bio->bi_rw & REQ_RAHEAD)
575		dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
576
577	cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
578
579	memset(cmnd, 0, sizeof(*cmnd));
580	if (bio_data_dir(bio)) {
581		cmnd->rw.opcode = nvme_cmd_write;
582		dma_dir = DMA_TO_DEVICE;
583	} else {
584		cmnd->rw.opcode = nvme_cmd_read;
585		dma_dir = DMA_FROM_DEVICE;
586	}
587
588	result = nvme_map_bio(nvmeq->q_dmadev, iod, bio, dma_dir, psegs);
589	if (result < 0)
590		goto free_iod;
591	length = result;
592
593	cmnd->rw.command_id = cmdid;
594	cmnd->rw.nsid = cpu_to_le32(ns->ns_id);
595	length = nvme_setup_prps(nvmeq->dev, &cmnd->common, iod, length,
596								GFP_ATOMIC);
597	cmnd->rw.slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));
598	cmnd->rw.length = cpu_to_le16((length >> ns->lba_shift) - 1);
599	cmnd->rw.control = cpu_to_le16(control);
600	cmnd->rw.dsmgmt = cpu_to_le32(dsmgmt);
601
602	bio->bi_sector += length >> 9;
603
604	if (++nvmeq->sq_tail == nvmeq->q_depth)
605		nvmeq->sq_tail = 0;
606	writel(nvmeq->sq_tail, nvmeq->q_db);
607
608	return 0;
609
610 free_iod:
611	nvme_free_iod(nvmeq->dev, iod);
612 nomem:
613	return result;
614}
615
616/*
617 * NB: return value of non-zero would mean that we were a stacking driver.
618 * make_request must always succeed.
619 */
620static int nvme_make_request(struct request_queue *q, struct bio *bio)
621{
622	struct nvme_ns *ns = q->queuedata;
623	struct nvme_queue *nvmeq = get_nvmeq(ns->dev);
624	int result = -EBUSY;
625
626	spin_lock_irq(&nvmeq->q_lock);
627	if (bio_list_empty(&nvmeq->sq_cong))
628		result = nvme_submit_bio_queue(nvmeq, ns, bio);
629	if (unlikely(result)) {
630		if (bio_list_empty(&nvmeq->sq_cong))
631			add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
632		bio_list_add(&nvmeq->sq_cong, bio);
633	}
634
635	spin_unlock_irq(&nvmeq->q_lock);
636	put_nvmeq(nvmeq);
637
638	return 0;
639}
640
641static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
642{
643	u16 head, phase;
644
645	head = nvmeq->cq_head;
646	phase = nvmeq->cq_phase;
647
648	for (;;) {
649		void *ctx;
650		nvme_completion_fn fn;
651		struct nvme_completion cqe = nvmeq->cqes[head];
652		if ((le16_to_cpu(cqe.status) & 1) != phase)
653			break;
654		nvmeq->sq_head = le16_to_cpu(cqe.sq_head);
655		if (++head == nvmeq->q_depth) {
656			head = 0;
657			phase = !phase;
658		}
659
660		ctx = free_cmdid(nvmeq, cqe.command_id, &fn);
661		fn(nvmeq->dev, ctx, &cqe);
662	}
663
664	/* If the controller ignores the cq head doorbell and continuously
665	 * writes to the queue, it is theoretically possible to wrap around
666	 * the queue twice and mistakenly return IRQ_NONE.  Linux only
667	 * requires that 0.1% of your interrupts are handled, so this isn't
668	 * a big problem.
669	 */
670	if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
671		return IRQ_NONE;
672
673	writel(head, nvmeq->q_db + (1 << nvmeq->dev->db_stride));
674	nvmeq->cq_head = head;
675	nvmeq->cq_phase = phase;
676
677	return IRQ_HANDLED;
678}
679
680static irqreturn_t nvme_irq(int irq, void *data)
681{
682	irqreturn_t result;
683	struct nvme_queue *nvmeq = data;
684	spin_lock(&nvmeq->q_lock);
685	result = nvme_process_cq(nvmeq);
686	spin_unlock(&nvmeq->q_lock);
687	return result;
688}
689
690static irqreturn_t nvme_irq_check(int irq, void *data)
691{
692	struct nvme_queue *nvmeq = data;
693	struct nvme_completion cqe = nvmeq->cqes[nvmeq->cq_head];
694	if ((le16_to_cpu(cqe.status) & 1) != nvmeq->cq_phase)
695		return IRQ_NONE;
696	return IRQ_WAKE_THREAD;
697}
698
699static void nvme_abort_command(struct nvme_queue *nvmeq, int cmdid)
700{
701	spin_lock_irq(&nvmeq->q_lock);
702	cancel_cmdid(nvmeq, cmdid, NULL);
703	spin_unlock_irq(&nvmeq->q_lock);
704}
705
706struct sync_cmd_info {
707	struct task_struct *task;
708	u32 result;
709	int status;
710};
711
712static void sync_completion(struct nvme_dev *dev, void *ctx,
713						struct nvme_completion *cqe)
714{
715	struct sync_cmd_info *cmdinfo = ctx;
716	cmdinfo->result = le32_to_cpup(&cqe->result);
717	cmdinfo->status = le16_to_cpup(&cqe->status) >> 1;
718	wake_up_process(cmdinfo->task);
719}
720
721/*
722 * Returns 0 on success.  If the result is negative, it's a Linux error code;
723 * if the result is positive, it's an NVM Express status code
724 */
725static int nvme_submit_sync_cmd(struct nvme_queue *nvmeq,
726			struct nvme_command *cmd, u32 *result, unsigned timeout)
727{
728	int cmdid;
729	struct sync_cmd_info cmdinfo;
730
731	cmdinfo.task = current;
732	cmdinfo.status = -EINTR;
733
734	cmdid = alloc_cmdid_killable(nvmeq, &cmdinfo, sync_completion,
735								timeout);
736	if (cmdid < 0)
737		return cmdid;
738	cmd->common.command_id = cmdid;
739
740	set_current_state(TASK_KILLABLE);
741	nvme_submit_cmd(nvmeq, cmd);
742	schedule();
743
744	if (cmdinfo.status == -EINTR) {
745		nvme_abort_command(nvmeq, cmdid);
746		return -EINTR;
747	}
748
749	if (result)
750		*result = cmdinfo.result;
751
752	return cmdinfo.status;
753}
754
755static int nvme_submit_admin_cmd(struct nvme_dev *dev, struct nvme_command *cmd,
756								u32 *result)
757{
758	return nvme_submit_sync_cmd(dev->queues[0], cmd, result, ADMIN_TIMEOUT);
759}
760
761static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
762{
763	int status;
764	struct nvme_command c;
765
766	memset(&c, 0, sizeof(c));
767	c.delete_queue.opcode = opcode;
768	c.delete_queue.qid = cpu_to_le16(id);
769
770	status = nvme_submit_admin_cmd(dev, &c, NULL);
771	if (status)
772		return -EIO;
773	return 0;
774}
775
776static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
777						struct nvme_queue *nvmeq)
778{
779	int status;
780	struct nvme_command c;
781	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
782
783	memset(&c, 0, sizeof(c));
784	c.create_cq.opcode = nvme_admin_create_cq;
785	c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
786	c.create_cq.cqid = cpu_to_le16(qid);
787	c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
788	c.create_cq.cq_flags = cpu_to_le16(flags);
789	c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
790
791	status = nvme_submit_admin_cmd(dev, &c, NULL);
792	if (status)
793		return -EIO;
794	return 0;
795}
796
797static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
798						struct nvme_queue *nvmeq)
799{
800	int status;
801	struct nvme_command c;
802	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_SQ_PRIO_MEDIUM;
803
804	memset(&c, 0, sizeof(c));
805	c.create_sq.opcode = nvme_admin_create_sq;
806	c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
807	c.create_sq.sqid = cpu_to_le16(qid);
808	c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
809	c.create_sq.sq_flags = cpu_to_le16(flags);
810	c.create_sq.cqid = cpu_to_le16(qid);
811
812	status = nvme_submit_admin_cmd(dev, &c, NULL);
813	if (status)
814		return -EIO;
815	return 0;
816}
817
818static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
819{
820	return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
821}
822
823static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
824{
825	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
826}
827
828static int nvme_identify(struct nvme_dev *dev, unsigned nsid, unsigned cns,
829							dma_addr_t dma_addr)
830{
831	struct nvme_command c;
832
833	memset(&c, 0, sizeof(c));
834	c.identify.opcode = nvme_admin_identify;
835	c.identify.nsid = cpu_to_le32(nsid);
836	c.identify.prp1 = cpu_to_le64(dma_addr);
837	c.identify.cns = cpu_to_le32(cns);
838
839	return nvme_submit_admin_cmd(dev, &c, NULL);
840}
841
842static int nvme_get_features(struct nvme_dev *dev, unsigned fid,
843			unsigned dword11, dma_addr_t dma_addr, u32 *result)
844{
845	struct nvme_command c;
846
847	memset(&c, 0, sizeof(c));
848	c.features.opcode = nvme_admin_get_features;
849	c.features.prp1 = cpu_to_le64(dma_addr);
850	c.features.fid = cpu_to_le32(fid);
851	c.features.dword11 = cpu_to_le32(dword11);
852
853	return nvme_submit_admin_cmd(dev, &c, result);
854}
855
856static void nvme_free_queue(struct nvme_dev *dev, int qid)
857{
858	struct nvme_queue *nvmeq = dev->queues[qid];
859	int vector = dev->entry[nvmeq->cq_vector].vector;
860
861	irq_set_affinity_hint(vector, NULL);
862	free_irq(vector, nvmeq);
863
864	/* Don't tell the adapter to delete the admin queue */
865	if (qid) {
866		adapter_delete_sq(dev, qid);
867		adapter_delete_cq(dev, qid);
868	}
869
870	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
871				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
872	dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
873					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
874	kfree(nvmeq);
875}
876
877static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
878							int depth, int vector)
879{
880	struct device *dmadev = &dev->pci_dev->dev;
881	unsigned extra = (depth / 8) + (depth * sizeof(struct nvme_cmd_info));
882	struct nvme_queue *nvmeq = kzalloc(sizeof(*nvmeq) + extra, GFP_KERNEL);
883	if (!nvmeq)
884		return NULL;
885
886	nvmeq->cqes = dma_alloc_coherent(dmadev, CQ_SIZE(depth),
887					&nvmeq->cq_dma_addr, GFP_KERNEL);
888	if (!nvmeq->cqes)
889		goto free_nvmeq;
890	memset((void *)nvmeq->cqes, 0, CQ_SIZE(depth));
891
892	nvmeq->sq_cmds = dma_alloc_coherent(dmadev, SQ_SIZE(depth),
893					&nvmeq->sq_dma_addr, GFP_KERNEL);
894	if (!nvmeq->sq_cmds)
895		goto free_cqdma;
896
897	nvmeq->q_dmadev = dmadev;
898	nvmeq->dev = dev;
899	spin_lock_init(&nvmeq->q_lock);
900	nvmeq->cq_head = 0;
901	nvmeq->cq_phase = 1;
902	init_waitqueue_head(&nvmeq->sq_full);
903	init_waitqueue_entry(&nvmeq->sq_cong_wait, nvme_thread);
904	bio_list_init(&nvmeq->sq_cong);
905	nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)];
906	nvmeq->q_depth = depth;
907	nvmeq->cq_vector = vector;
908
909	return nvmeq;
910
911 free_cqdma:
912	dma_free_coherent(dmadev, CQ_SIZE(nvmeq->q_depth), (void *)nvmeq->cqes,
913							nvmeq->cq_dma_addr);
914 free_nvmeq:
915	kfree(nvmeq);
916	return NULL;
917}
918
919static int queue_request_irq(struct nvme_dev *dev, struct nvme_queue *nvmeq,
920							const char *name)
921{
922	if (use_threaded_interrupts)
923		return request_threaded_irq(dev->entry[nvmeq->cq_vector].vector,
924					nvme_irq_check, nvme_irq,
925					IRQF_DISABLED | IRQF_SHARED,
926					name, nvmeq);
927	return request_irq(dev->entry[nvmeq->cq_vector].vector, nvme_irq,
928				IRQF_DISABLED | IRQF_SHARED, name, nvmeq);
929}
930
931static __devinit struct nvme_queue *nvme_create_queue(struct nvme_dev *dev,
932					int qid, int cq_size, int vector)
933{
934	int result;
935	struct nvme_queue *nvmeq = nvme_alloc_queue(dev, qid, cq_size, vector);
936
937	if (!nvmeq)
938		return ERR_PTR(-ENOMEM);
939
940	result = adapter_alloc_cq(dev, qid, nvmeq);
941	if (result < 0)
942		goto free_nvmeq;
943
944	result = adapter_alloc_sq(dev, qid, nvmeq);
945	if (result < 0)
946		goto release_cq;
947
948	result = queue_request_irq(dev, nvmeq, "nvme");
949	if (result < 0)
950		goto release_sq;
951
952	return nvmeq;
953
954 release_sq:
955	adapter_delete_sq(dev, qid);
956 release_cq:
957	adapter_delete_cq(dev, qid);
958 free_nvmeq:
959	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
960				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
961	dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
962					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
963	kfree(nvmeq);
964	return ERR_PTR(result);
965}
966
967static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
968{
969	int result;
970	u32 aqa;
971	u64 cap;
972	unsigned long timeout;
973	struct nvme_queue *nvmeq;
974
975	dev->dbs = ((void __iomem *)dev->bar) + 4096;
976
977	nvmeq = nvme_alloc_queue(dev, 0, 64, 0);
978	if (!nvmeq)
979		return -ENOMEM;
980
981	aqa = nvmeq->q_depth - 1;
982	aqa |= aqa << 16;
983
984	dev->ctrl_config = NVME_CC_ENABLE | NVME_CC_CSS_NVM;
985	dev->ctrl_config |= (PAGE_SHIFT - 12) << NVME_CC_MPS_SHIFT;
986	dev->ctrl_config |= NVME_CC_ARB_RR | NVME_CC_SHN_NONE;
987	dev->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;
988
989	writel(0, &dev->bar->cc);
990	writel(aqa, &dev->bar->aqa);
991	writeq(nvmeq->sq_dma_addr, &dev->bar->asq);
992	writeq(nvmeq->cq_dma_addr, &dev->bar->acq);
993	writel(dev->ctrl_config, &dev->bar->cc);
994
995	cap = readq(&dev->bar->cap);
996	timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
997	dev->db_stride = NVME_CAP_STRIDE(cap);
998
999	while (!(readl(&dev->bar->csts) & NVME_CSTS_RDY)) {
1000		msleep(100);
1001		if (fatal_signal_pending(current))
1002			return -EINTR;
1003		if (time_after(jiffies, timeout)) {
1004			dev_err(&dev->pci_dev->dev,
1005				"Device not ready; aborting initialisation\n");
1006			return -ENODEV;
1007		}
1008	}
1009
1010	result = queue_request_irq(dev, nvmeq, "nvme admin");
1011	dev->queues[0] = nvmeq;
1012	return result;
1013}
1014
1015static struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write,
1016				unsigned long addr, unsigned length)
1017{
1018	int i, err, count, nents, offset;
1019	struct scatterlist *sg;
1020	struct page **pages;
1021	struct nvme_iod *iod;
1022
1023	if (addr & 3)
1024		return ERR_PTR(-EINVAL);
1025	if (!length)
1026		return ERR_PTR(-EINVAL);
1027
1028	offset = offset_in_page(addr);
1029	count = DIV_ROUND_UP(offset + length, PAGE_SIZE);
1030	pages = kcalloc(count, sizeof(*pages), GFP_KERNEL);
1031
1032	err = get_user_pages_fast(addr, count, 1, pages);
1033	if (err < count) {
1034		count = err;
1035		err = -EFAULT;
1036		goto put_pages;
1037	}
1038
1039	iod = nvme_alloc_iod(count, length, GFP_KERNEL);
1040	sg = iod->sg;
1041	sg_init_table(sg, count);
1042	for (i = 0; i < count; i++) {
1043		sg_set_page(&sg[i], pages[i],
1044				min_t(int, length, PAGE_SIZE - offset), offset);
1045		length -= (PAGE_SIZE - offset);
1046		offset = 0;
1047	}
1048
1049	err = -ENOMEM;
1050	nents = dma_map_sg(&dev->pci_dev->dev, sg, count,
1051				write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
1052	if (!nents)
1053		goto free_iod;
1054
1055	kfree(pages);
1056	return iod;
1057
1058 free_iod:
1059	kfree(iod);
1060 put_pages:
1061	for (i = 0; i < count; i++)
1062		put_page(pages[i]);
1063	kfree(pages);
1064	return ERR_PTR(err);
1065}
1066
1067static void nvme_unmap_user_pages(struct nvme_dev *dev, int write,
1068			unsigned long addr, int length, struct nvme_iod *iod)
1069{
1070	struct scatterlist *sg = iod->sg;
1071	int i, count;
1072
1073	count = DIV_ROUND_UP(offset_in_page(addr) + length, PAGE_SIZE);
1074	dma_unmap_sg(&dev->pci_dev->dev, sg, count, DMA_FROM_DEVICE);
1075
1076	for (i = 0; i < count; i++)
1077		put_page(sg_page(&sg[i]));
1078}
1079
1080static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
1081{
1082	struct nvme_dev *dev = ns->dev;
1083	struct nvme_queue *nvmeq;
1084	struct nvme_user_io io;
1085	struct nvme_command c;
1086	unsigned length;
1087	int status;
1088	struct nvme_iod *iod;
1089
1090	if (copy_from_user(&io, uio, sizeof(io)))
1091		return -EFAULT;
1092	length = (io.nblocks + 1) << ns->lba_shift;
1093
1094	switch (io.opcode) {
1095	case nvme_cmd_write:
1096	case nvme_cmd_read:
1097	case nvme_cmd_compare:
1098		iod = nvme_map_user_pages(dev, io.opcode & 1, io.addr, length);
1099		break;
1100	default:
1101		return -EINVAL;
1102	}
1103
1104	if (IS_ERR(iod))
1105		return PTR_ERR(iod);
1106
1107	memset(&c, 0, sizeof(c));
1108	c.rw.opcode = io.opcode;
1109	c.rw.flags = io.flags;
1110	c.rw.nsid = cpu_to_le32(ns->ns_id);
1111	c.rw.slba = cpu_to_le64(io.slba);
1112	c.rw.length = cpu_to_le16(io.nblocks);
1113	c.rw.control = cpu_to_le16(io.control);
1114	c.rw.dsmgmt = cpu_to_le16(io.dsmgmt);
1115	c.rw.reftag = io.reftag;
1116	c.rw.apptag = io.apptag;
1117	c.rw.appmask = io.appmask;
1118	/* XXX: metadata */
1119	length = nvme_setup_prps(dev, &c.common, iod, length, GFP_KERNEL);
1120
1121	nvmeq = get_nvmeq(dev);
1122	/*
1123	 * Since nvme_submit_sync_cmd sleeps, we can't keep preemption
1124	 * disabled.  We may be preempted at any point, and be rescheduled
1125	 * to a different CPU.  That will cause cacheline bouncing, but no
1126	 * additional races since q_lock already protects against other CPUs.
1127	 */
1128	put_nvmeq(nvmeq);
1129	if (length != (io.nblocks + 1) << ns->lba_shift)
1130		status = -ENOMEM;
1131	else
1132		status = nvme_submit_sync_cmd(nvmeq, &c, NULL, IO_TIMEOUT);
1133
1134	nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, iod);
1135	nvme_free_iod(dev, iod);
1136	return status;
1137}
1138
1139static int nvme_user_admin_cmd(struct nvme_ns *ns,
1140					struct nvme_admin_cmd __user *ucmd)
1141{
1142	struct nvme_dev *dev = ns->dev;
1143	struct nvme_admin_cmd cmd;
1144	struct nvme_command c;
1145	int status, length;
1146	struct nvme_iod *iod;
1147
1148	if (!capable(CAP_SYS_ADMIN))
1149		return -EACCES;
1150	if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
1151		return -EFAULT;
1152
1153	memset(&c, 0, sizeof(c));
1154	c.common.opcode = cmd.opcode;
1155	c.common.flags = cmd.flags;
1156	c.common.nsid = cpu_to_le32(cmd.nsid);
1157	c.common.cdw2[0] = cpu_to_le32(cmd.cdw2);
1158	c.common.cdw2[1] = cpu_to_le32(cmd.cdw3);
1159	c.common.cdw10[0] = cpu_to_le32(cmd.cdw10);
1160	c.common.cdw10[1] = cpu_to_le32(cmd.cdw11);
1161	c.common.cdw10[2] = cpu_to_le32(cmd.cdw12);
1162	c.common.cdw10[3] = cpu_to_le32(cmd.cdw13);
1163	c.common.cdw10[4] = cpu_to_le32(cmd.cdw14);
1164	c.common.cdw10[5] = cpu_to_le32(cmd.cdw15);
1165
1166	length = cmd.data_len;
1167	if (cmd.data_len) {
1168		iod = nvme_map_user_pages(dev, 1, cmd.addr, length);
1169		if (IS_ERR(iod))
1170			return PTR_ERR(iod);
1171		length = nvme_setup_prps(dev, &c.common, iod, length,
1172								GFP_KERNEL);
1173	}
1174
1175	if (length != cmd.data_len)
1176		status = -ENOMEM;
1177	else
1178		status = nvme_submit_admin_cmd(dev, &c, NULL);
1179
1180	if (cmd.data_len) {
1181		nvme_unmap_user_pages(dev, 0, cmd.addr, cmd.data_len, iod);
1182		nvme_free_iod(dev, iod);
1183	}
1184	return status;
1185}
1186
1187static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
1188							unsigned long arg)
1189{
1190	struct nvme_ns *ns = bdev->bd_disk->private_data;
1191
1192	switch (cmd) {
1193	case NVME_IOCTL_ID:
1194		return ns->ns_id;
1195	case NVME_IOCTL_ADMIN_CMD:
1196		return nvme_user_admin_cmd(ns, (void __user *)arg);
1197	case NVME_IOCTL_SUBMIT_IO:
1198		return nvme_submit_io(ns, (void __user *)arg);
1199	default:
1200		return -ENOTTY;
1201	}
1202}
1203
1204static const struct block_device_operations nvme_fops = {
1205	.owner		= THIS_MODULE,
1206	.ioctl		= nvme_ioctl,
1207	.compat_ioctl	= nvme_ioctl,
1208};
1209
1210static void nvme_timeout_ios(struct nvme_queue *nvmeq)
1211{
1212	int depth = nvmeq->q_depth - 1;
1213	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
1214	unsigned long now = jiffies;
1215	int cmdid;
1216
1217	for_each_set_bit(cmdid, nvmeq->cmdid_data, depth) {
1218		void *ctx;
1219		nvme_completion_fn fn;
1220		static struct nvme_completion cqe = { .status = cpu_to_le16(NVME_SC_ABORT_REQ) << 1, };
1221
1222		if (!time_after(now, info[cmdid].timeout))
1223			continue;
1224		dev_warn(nvmeq->q_dmadev, "Timing out I/O %d\n", cmdid);
1225		ctx = cancel_cmdid(nvmeq, cmdid, &fn);
1226		fn(nvmeq->dev, ctx, &cqe);
1227	}
1228}
1229
1230static void nvme_resubmit_bios(struct nvme_queue *nvmeq)
1231{
1232	while (bio_list_peek(&nvmeq->sq_cong)) {
1233		struct bio *bio = bio_list_pop(&nvmeq->sq_cong);
1234		struct nvme_ns *ns = bio->bi_bdev->bd_disk->private_data;
1235		if (nvme_submit_bio_queue(nvmeq, ns, bio)) {
1236			bio_list_add_head(&nvmeq->sq_cong, bio);
1237			break;
1238		}
1239		if (bio_list_empty(&nvmeq->sq_cong))
1240			remove_wait_queue(&nvmeq->sq_full,
1241							&nvmeq->sq_cong_wait);
1242	}
1243}
1244
1245static int nvme_kthread(void *data)
1246{
1247	struct nvme_dev *dev;
1248
1249	while (!kthread_should_stop()) {
1250		__set_current_state(TASK_RUNNING);
1251		spin_lock(&dev_list_lock);
1252		list_for_each_entry(dev, &dev_list, node) {
1253			int i;
1254			for (i = 0; i < dev->queue_count; i++) {
1255				struct nvme_queue *nvmeq = dev->queues[i];
1256				if (!nvmeq)
1257					continue;
1258				spin_lock_irq(&nvmeq->q_lock);
1259				if (nvme_process_cq(nvmeq))
1260					printk("process_cq did something\n");
1261				nvme_timeout_ios(nvmeq);
1262				nvme_resubmit_bios(nvmeq);
1263				spin_unlock_irq(&nvmeq->q_lock);
1264			}
1265		}
1266		spin_unlock(&dev_list_lock);
1267		set_current_state(TASK_INTERRUPTIBLE);
1268		schedule_timeout(HZ);
1269	}
1270	return 0;
1271}
1272
1273static DEFINE_IDA(nvme_index_ida);
1274
1275static int nvme_get_ns_idx(void)
1276{
1277	int index, error;
1278
1279	do {
1280		if (!ida_pre_get(&nvme_index_ida, GFP_KERNEL))
1281			return -1;
1282
1283		spin_lock(&dev_list_lock);
1284		error = ida_get_new(&nvme_index_ida, &index);
1285		spin_unlock(&dev_list_lock);
1286	} while (error == -EAGAIN);
1287
1288	if (error)
1289		index = -1;
1290	return index;
1291}
1292
1293static void nvme_put_ns_idx(int index)
1294{
1295	spin_lock(&dev_list_lock);
1296	ida_remove(&nvme_index_ida, index);
1297	spin_unlock(&dev_list_lock);
1298}
1299
1300static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid,
1301			struct nvme_id_ns *id, struct nvme_lba_range_type *rt)
1302{
1303	struct nvme_ns *ns;
1304	struct gendisk *disk;
1305	int lbaf;
1306
1307	if (rt->attributes & NVME_LBART_ATTRIB_HIDE)
1308		return NULL;
1309
1310	ns = kzalloc(sizeof(*ns), GFP_KERNEL);
1311	if (!ns)
1312		return NULL;
1313	ns->queue = blk_alloc_queue(GFP_KERNEL);
1314	if (!ns->queue)
1315		goto out_free_ns;
1316	ns->queue->queue_flags = QUEUE_FLAG_DEFAULT | QUEUE_FLAG_NOMERGES |
1317				QUEUE_FLAG_NONROT | QUEUE_FLAG_DISCARD;
1318	blk_queue_make_request(ns->queue, nvme_make_request);
1319	ns->dev = dev;
1320	ns->queue->queuedata = ns;
1321
1322	disk = alloc_disk(NVME_MINORS);
1323	if (!disk)
1324		goto out_free_queue;
1325	ns->ns_id = nsid;
1326	ns->disk = disk;
1327	lbaf = id->flbas & 0xf;
1328	ns->lba_shift = id->lbaf[lbaf].ds;
1329
1330	disk->major = nvme_major;
1331	disk->minors = NVME_MINORS;
1332	disk->first_minor = NVME_MINORS * nvme_get_ns_idx();
1333	disk->fops = &nvme_fops;
1334	disk->private_data = ns;
1335	disk->queue = ns->queue;
1336	disk->driverfs_dev = &dev->pci_dev->dev;
1337	sprintf(disk->disk_name, "nvme%dn%d", dev->instance, nsid);
1338	set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
1339
1340	return ns;
1341
1342 out_free_queue:
1343	blk_cleanup_queue(ns->queue);
1344 out_free_ns:
1345	kfree(ns);
1346	return NULL;
1347}
1348
1349static void nvme_ns_free(struct nvme_ns *ns)
1350{
1351	int index = ns->disk->first_minor / NVME_MINORS;
1352	put_disk(ns->disk);
1353	nvme_put_ns_idx(index);
1354	blk_cleanup_queue(ns->queue);
1355	kfree(ns);
1356}
1357
1358static int set_queue_count(struct nvme_dev *dev, int count)
1359{
1360	int status;
1361	u32 result;
1362	u32 q_count = (count - 1) | ((count - 1) << 16);
1363
1364	status = nvme_get_features(dev, NVME_FEAT_NUM_QUEUES, q_count, 0,
1365								&result);
1366	if (status)
1367		return -EIO;
1368	return min(result & 0xffff, result >> 16) + 1;
1369}
1370
1371static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
1372{
1373	int result, cpu, i, nr_io_queues, db_bar_size;
1374
1375	nr_io_queues = num_online_cpus();
1376	result = set_queue_count(dev, nr_io_queues);
1377	if (result < 0)
1378		return result;
1379	if (result < nr_io_queues)
1380		nr_io_queues = result;
1381
1382	/* Deregister the admin queue's interrupt */
1383	free_irq(dev->entry[0].vector, dev->queues[0]);
1384
1385	db_bar_size = 4096 + ((nr_io_queues + 1) << (dev->db_stride + 3));
1386	if (db_bar_size > 8192) {
1387		iounmap(dev->bar);
1388		dev->bar = ioremap(pci_resource_start(dev->pci_dev, 0),
1389								db_bar_size);
1390		dev->dbs = ((void __iomem *)dev->bar) + 4096;
1391		dev->queues[0]->q_db = dev->dbs;
1392	}
1393
1394	for (i = 0; i < nr_io_queues; i++)
1395		dev->entry[i].entry = i;
1396	for (;;) {
1397		result = pci_enable_msix(dev->pci_dev, dev->entry,
1398								nr_io_queues);
1399		if (result == 0) {
1400			break;
1401		} else if (result > 0) {
1402			nr_io_queues = result;
1403			continue;
1404		} else {
1405			nr_io_queues = 1;
1406			break;
1407		}
1408	}
1409
1410	result = queue_request_irq(dev, dev->queues[0], "nvme admin");
1411	/* XXX: handle failure here */
1412
1413	cpu = cpumask_first(cpu_online_mask);
1414	for (i = 0; i < nr_io_queues; i++) {
1415		irq_set_affinity_hint(dev->entry[i].vector, get_cpu_mask(cpu));
1416		cpu = cpumask_next(cpu, cpu_online_mask);
1417	}
1418
1419	for (i = 0; i < nr_io_queues; i++) {
1420		dev->queues[i + 1] = nvme_create_queue(dev, i + 1,
1421							NVME_Q_DEPTH, i);
1422		if (IS_ERR(dev->queues[i + 1]))
1423			return PTR_ERR(dev->queues[i + 1]);
1424		dev->queue_count++;
1425	}
1426
1427	for (; i < num_possible_cpus(); i++) {
1428		int target = i % rounddown_pow_of_two(dev->queue_count - 1);
1429		dev->queues[i + 1] = dev->queues[target + 1];
1430	}
1431
1432	return 0;
1433}
1434
1435static void nvme_free_queues(struct nvme_dev *dev)
1436{
1437	int i;
1438
1439	for (i = dev->queue_count - 1; i >= 0; i--)
1440		nvme_free_queue(dev, i);
1441}
1442
1443static int __devinit nvme_dev_add(struct nvme_dev *dev)
1444{
1445	int res, nn, i;
1446	struct nvme_ns *ns, *next;
1447	struct nvme_id_ctrl *ctrl;
1448	struct nvme_id_ns *id_ns;
1449	void *mem;
1450	dma_addr_t dma_addr;
1451
1452	res = nvme_setup_io_queues(dev);
1453	if (res)
1454		return res;
1455
1456	mem = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
1457								GFP_KERNEL);
1458
1459	res = nvme_identify(dev, 0, 1, dma_addr);
1460	if (res) {
1461		res = -EIO;
1462		goto out_free;
1463	}
1464
1465	ctrl = mem;
1466	nn = le32_to_cpup(&ctrl->nn);
1467	memcpy(dev->serial, ctrl->sn, sizeof(ctrl->sn));
1468	memcpy(dev->model, ctrl->mn, sizeof(ctrl->mn));
1469	memcpy(dev->firmware_rev, ctrl->fr, sizeof(ctrl->fr));
1470
1471	id_ns = mem;
1472	for (i = 1; i <= nn; i++) {
1473		res = nvme_identify(dev, i, 0, dma_addr);
1474		if (res)
1475			continue;
1476
1477		if (id_ns->ncap == 0)
1478			continue;
1479
1480		res = nvme_get_features(dev, NVME_FEAT_LBA_RANGE, i,
1481							dma_addr + 4096, NULL);
1482		if (res)
1483			continue;
1484
1485		ns = nvme_alloc_ns(dev, i, mem, mem + 4096);
1486		if (ns)
1487			list_add_tail(&ns->list, &dev->namespaces);
1488	}
1489	list_for_each_entry(ns, &dev->namespaces, list)
1490		add_disk(ns->disk);
1491
1492	goto out;
1493
1494 out_free:
1495	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
1496		list_del(&ns->list);
1497		nvme_ns_free(ns);
1498	}
1499
1500 out:
1501	dma_free_coherent(&dev->pci_dev->dev, 8192, mem, dma_addr);
1502	return res;
1503}
1504
1505static int nvme_dev_remove(struct nvme_dev *dev)
1506{
1507	struct nvme_ns *ns, *next;
1508
1509	spin_lock(&dev_list_lock);
1510	list_del(&dev->node);
1511	spin_unlock(&dev_list_lock);
1512
1513	/* TODO: wait all I/O finished or cancel them */
1514
1515	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
1516		list_del(&ns->list);
1517		del_gendisk(ns->disk);
1518		nvme_ns_free(ns);
1519	}
1520
1521	nvme_free_queues(dev);
1522
1523	return 0;
1524}
1525
1526static int nvme_setup_prp_pools(struct nvme_dev *dev)
1527{
1528	struct device *dmadev = &dev->pci_dev->dev;
1529	dev->prp_page_pool = dma_pool_create("prp list page", dmadev,
1530						PAGE_SIZE, PAGE_SIZE, 0);
1531	if (!dev->prp_page_pool)
1532		return -ENOMEM;
1533
1534	/* Optimisation for I/Os between 4k and 128k */
1535	dev->prp_small_pool = dma_pool_create("prp list 256", dmadev,
1536						256, 256, 0);
1537	if (!dev->prp_small_pool) {
1538		dma_pool_destroy(dev->prp_page_pool);
1539		return -ENOMEM;
1540	}
1541	return 0;
1542}
1543
1544static void nvme_release_prp_pools(struct nvme_dev *dev)
1545{
1546	dma_pool_destroy(dev->prp_page_pool);
1547	dma_pool_destroy(dev->prp_small_pool);
1548}
1549
1550/* XXX: Use an ida or something to let remove / add work correctly */
1551static void nvme_set_instance(struct nvme_dev *dev)
1552{
1553	static int instance;
1554	dev->instance = instance++;
1555}
1556
1557static void nvme_release_instance(struct nvme_dev *dev)
1558{
1559}
1560
1561static int __devinit nvme_probe(struct pci_dev *pdev,
1562						const struct pci_device_id *id)
1563{
1564	int bars, result = -ENOMEM;
1565	struct nvme_dev *dev;
1566
1567	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1568	if (!dev)
1569		return -ENOMEM;
1570	dev->entry = kcalloc(num_possible_cpus(), sizeof(*dev->entry),
1571								GFP_KERNEL);
1572	if (!dev->entry)
1573		goto free;
1574	dev->queues = kcalloc(num_possible_cpus() + 1, sizeof(void *),
1575								GFP_KERNEL);
1576	if (!dev->queues)
1577		goto free;
1578
1579	if (pci_enable_device_mem(pdev))
1580		goto free;
1581	pci_set_master(pdev);
1582	bars = pci_select_bars(pdev, IORESOURCE_MEM);
1583	if (pci_request_selected_regions(pdev, bars, "nvme"))
1584		goto disable;
1585
1586	INIT_LIST_HEAD(&dev->namespaces);
1587	dev->pci_dev = pdev;
1588	pci_set_drvdata(pdev, dev);
1589	dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
1590	dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
1591	nvme_set_instance(dev);
1592	dev->entry[0].vector = pdev->irq;
1593
1594	result = nvme_setup_prp_pools(dev);
1595	if (result)
1596		goto disable_msix;
1597
1598	dev->bar = ioremap(pci_resource_start(pdev, 0), 8192);
1599	if (!dev->bar) {
1600		result = -ENOMEM;
1601		goto disable_msix;
1602	}
1603
1604	result = nvme_configure_admin_queue(dev);
1605	if (result)
1606		goto unmap;
1607	dev->queue_count++;
1608
1609	spin_lock(&dev_list_lock);
1610	list_add(&dev->node, &dev_list);
1611	spin_unlock(&dev_list_lock);
1612
1613	result = nvme_dev_add(dev);
1614	if (result)
1615		goto delete;
1616
1617	return 0;
1618
1619 delete:
1620	spin_lock(&dev_list_lock);
1621	list_del(&dev->node);
1622	spin_unlock(&dev_list_lock);
1623
1624	nvme_free_queues(dev);
1625 unmap:
1626	iounmap(dev->bar);
1627 disable_msix:
1628	pci_disable_msix(pdev);
1629	nvme_release_instance(dev);
1630	nvme_release_prp_pools(dev);
1631 disable:
1632	pci_disable_device(pdev);
1633	pci_release_regions(pdev);
1634 free:
1635	kfree(dev->queues);
1636	kfree(dev->entry);
1637	kfree(dev);
1638	return result;
1639}
1640
1641static void __devexit nvme_remove(struct pci_dev *pdev)
1642{
1643	struct nvme_dev *dev = pci_get_drvdata(pdev);
1644	nvme_dev_remove(dev);
1645	pci_disable_msix(pdev);
1646	iounmap(dev->bar);
1647	nvme_release_instance(dev);
1648	nvme_release_prp_pools(dev);
1649	pci_disable_device(pdev);
1650	pci_release_regions(pdev);
1651	kfree(dev->queues);
1652	kfree(dev->entry);
1653	kfree(dev);
1654}
1655
1656/* These functions are yet to be implemented */
1657#define nvme_error_detected NULL
1658#define nvme_dump_registers NULL
1659#define nvme_link_reset NULL
1660#define nvme_slot_reset NULL
1661#define nvme_error_resume NULL
1662#define nvme_suspend NULL
1663#define nvme_resume NULL
1664
1665static struct pci_error_handlers nvme_err_handler = {
1666	.error_detected	= nvme_error_detected,
1667	.mmio_enabled	= nvme_dump_registers,
1668	.link_reset	= nvme_link_reset,
1669	.slot_reset	= nvme_slot_reset,
1670	.resume		= nvme_error_resume,
1671};
1672
1673/* Move to pci_ids.h later */
1674#define PCI_CLASS_STORAGE_EXPRESS	0x010802
1675
1676static DEFINE_PCI_DEVICE_TABLE(nvme_id_table) = {
1677	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
1678	{ 0, }
1679};
1680MODULE_DEVICE_TABLE(pci, nvme_id_table);
1681
1682static struct pci_driver nvme_driver = {
1683	.name		= "nvme",
1684	.id_table	= nvme_id_table,
1685	.probe		= nvme_probe,
1686	.remove		= __devexit_p(nvme_remove),
1687	.suspend	= nvme_suspend,
1688	.resume		= nvme_resume,
1689	.err_handler	= &nvme_err_handler,
1690};
1691
1692static int __init nvme_init(void)
1693{
1694	int result = -EBUSY;
1695
1696	nvme_thread = kthread_run(nvme_kthread, NULL, "nvme");
1697	if (IS_ERR(nvme_thread))
1698		return PTR_ERR(nvme_thread);
1699
1700	nvme_major = register_blkdev(nvme_major, "nvme");
1701	if (nvme_major <= 0)
1702		goto kill_kthread;
1703
1704	result = pci_register_driver(&nvme_driver);
1705	if (result)
1706		goto unregister_blkdev;
1707	return 0;
1708
1709 unregister_blkdev:
1710	unregister_blkdev(nvme_major, "nvme");
1711 kill_kthread:
1712	kthread_stop(nvme_thread);
1713	return result;
1714}
1715
1716static void __exit nvme_exit(void)
1717{
1718	pci_unregister_driver(&nvme_driver);
1719	unregister_blkdev(nvme_major, "nvme");
1720	kthread_stop(nvme_thread);
1721}
1722
1723MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
1724MODULE_LICENSE("GPL");
1725MODULE_VERSION("0.7");
1726module_init(nvme_init);
1727module_exit(nvme_exit);
1728