nvme-core.c revision 08df1e05657fc6712e520e7c09cc6c86160ceb35
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
43#include <asm-generic/io-64-nonatomic-lo-hi.h>
44
45#define NVME_Q_DEPTH 1024
46#define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
47#define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))
48#define NVME_MINORS 64
49#define NVME_IO_TIMEOUT	(5 * HZ)
50#define ADMIN_TIMEOUT	(60 * HZ)
51
52static int nvme_major;
53module_param(nvme_major, int, 0);
54
55static int use_threaded_interrupts;
56module_param(use_threaded_interrupts, int, 0);
57
58static DEFINE_SPINLOCK(dev_list_lock);
59static LIST_HEAD(dev_list);
60static struct task_struct *nvme_thread;
61
62/*
63 * Represents an NVM Express device.  Each nvme_dev is a PCI function.
64 */
65struct nvme_dev {
66	struct list_head node;
67	struct nvme_queue **queues;
68	u32 __iomem *dbs;
69	struct pci_dev *pci_dev;
70	struct dma_pool *prp_page_pool;
71	struct dma_pool *prp_small_pool;
72	int instance;
73	int queue_count;
74	int db_stride;
75	u32 ctrl_config;
76	struct msix_entry *entry;
77	struct nvme_bar __iomem *bar;
78	struct list_head namespaces;
79	char serial[20];
80	char model[40];
81	char firmware_rev[8];
82	u32 max_hw_sectors;
83};
84
85/*
86 * An NVM Express namespace is equivalent to a SCSI LUN
87 */
88struct nvme_ns {
89	struct list_head list;
90
91	struct nvme_dev *dev;
92	struct request_queue *queue;
93	struct gendisk *disk;
94
95	int ns_id;
96	int lba_shift;
97};
98
99/*
100 * An NVM Express queue.  Each device has at least two (one for admin
101 * commands and one for I/O commands).
102 */
103struct nvme_queue {
104	struct device *q_dmadev;
105	struct nvme_dev *dev;
106	spinlock_t q_lock;
107	struct nvme_command *sq_cmds;
108	volatile struct nvme_completion *cqes;
109	dma_addr_t sq_dma_addr;
110	dma_addr_t cq_dma_addr;
111	wait_queue_head_t sq_full;
112	wait_queue_t sq_cong_wait;
113	struct bio_list sq_cong;
114	u32 __iomem *q_db;
115	u16 q_depth;
116	u16 cq_vector;
117	u16 sq_head;
118	u16 sq_tail;
119	u16 cq_head;
120	u16 cq_phase;
121	unsigned long cmdid_data[];
122};
123
124/*
125 * Check we didin't inadvertently grow the command struct
126 */
127static inline void _nvme_check_size(void)
128{
129	BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
130	BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
131	BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
132	BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
133	BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
134	BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
135	BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != 4096);
136	BUILD_BUG_ON(sizeof(struct nvme_id_ns) != 4096);
137	BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
138}
139
140typedef void (*nvme_completion_fn)(struct nvme_dev *, void *,
141						struct nvme_completion *);
142
143struct nvme_cmd_info {
144	nvme_completion_fn fn;
145	void *ctx;
146	unsigned long timeout;
147};
148
149static struct nvme_cmd_info *nvme_cmd_info(struct nvme_queue *nvmeq)
150{
151	return (void *)&nvmeq->cmdid_data[BITS_TO_LONGS(nvmeq->q_depth)];
152}
153
154/**
155 * alloc_cmdid() - Allocate a Command ID
156 * @nvmeq: The queue that will be used for this command
157 * @ctx: A pointer that will be passed to the handler
158 * @handler: The function to call on completion
159 *
160 * Allocate a Command ID for a queue.  The data passed in will
161 * be passed to the completion handler.  This is implemented by using
162 * the bottom two bits of the ctx pointer to store the handler ID.
163 * Passing in a pointer that's not 4-byte aligned will cause a BUG.
164 * We can change this if it becomes a problem.
165 *
166 * May be called with local interrupts disabled and the q_lock held,
167 * or with interrupts enabled and no locks held.
168 */
169static int alloc_cmdid(struct nvme_queue *nvmeq, void *ctx,
170				nvme_completion_fn handler, unsigned timeout)
171{
172	int depth = nvmeq->q_depth - 1;
173	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
174	int cmdid;
175
176	do {
177		cmdid = find_first_zero_bit(nvmeq->cmdid_data, depth);
178		if (cmdid >= depth)
179			return -EBUSY;
180	} while (test_and_set_bit(cmdid, nvmeq->cmdid_data));
181
182	info[cmdid].fn = handler;
183	info[cmdid].ctx = ctx;
184	info[cmdid].timeout = jiffies + timeout;
185	return cmdid;
186}
187
188static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
189				nvme_completion_fn handler, unsigned timeout)
190{
191	int cmdid;
192	wait_event_killable(nvmeq->sq_full,
193		(cmdid = alloc_cmdid(nvmeq, ctx, handler, timeout)) >= 0);
194	return (cmdid < 0) ? -EINTR : cmdid;
195}
196
197/* Special values must be less than 0x1000 */
198#define CMD_CTX_BASE		((void *)POISON_POINTER_DELTA)
199#define CMD_CTX_CANCELLED	(0x30C + CMD_CTX_BASE)
200#define CMD_CTX_COMPLETED	(0x310 + CMD_CTX_BASE)
201#define CMD_CTX_INVALID		(0x314 + CMD_CTX_BASE)
202#define CMD_CTX_FLUSH		(0x318 + CMD_CTX_BASE)
203
204static void special_completion(struct nvme_dev *dev, void *ctx,
205						struct nvme_completion *cqe)
206{
207	if (ctx == CMD_CTX_CANCELLED)
208		return;
209	if (ctx == CMD_CTX_FLUSH)
210		return;
211	if (ctx == CMD_CTX_COMPLETED) {
212		dev_warn(&dev->pci_dev->dev,
213				"completed id %d twice on queue %d\n",
214				cqe->command_id, le16_to_cpup(&cqe->sq_id));
215		return;
216	}
217	if (ctx == CMD_CTX_INVALID) {
218		dev_warn(&dev->pci_dev->dev,
219				"invalid id %d completed on queue %d\n",
220				cqe->command_id, le16_to_cpup(&cqe->sq_id));
221		return;
222	}
223
224	dev_warn(&dev->pci_dev->dev, "Unknown special completion %p\n", ctx);
225}
226
227/*
228 * Called with local interrupts disabled and the q_lock held.  May not sleep.
229 */
230static void *free_cmdid(struct nvme_queue *nvmeq, int cmdid,
231						nvme_completion_fn *fn)
232{
233	void *ctx;
234	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
235
236	if (cmdid >= nvmeq->q_depth) {
237		*fn = special_completion;
238		return CMD_CTX_INVALID;
239	}
240	if (fn)
241		*fn = info[cmdid].fn;
242	ctx = info[cmdid].ctx;
243	info[cmdid].fn = special_completion;
244	info[cmdid].ctx = CMD_CTX_COMPLETED;
245	clear_bit(cmdid, nvmeq->cmdid_data);
246	wake_up(&nvmeq->sq_full);
247	return ctx;
248}
249
250static void *cancel_cmdid(struct nvme_queue *nvmeq, int cmdid,
251						nvme_completion_fn *fn)
252{
253	void *ctx;
254	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
255	if (fn)
256		*fn = info[cmdid].fn;
257	ctx = info[cmdid].ctx;
258	info[cmdid].fn = special_completion;
259	info[cmdid].ctx = CMD_CTX_CANCELLED;
260	return ctx;
261}
262
263static struct nvme_queue *get_nvmeq(struct nvme_dev *dev)
264{
265	return dev->queues[get_cpu() + 1];
266}
267
268static void put_nvmeq(struct nvme_queue *nvmeq)
269{
270	put_cpu();
271}
272
273/**
274 * nvme_submit_cmd() - Copy a command into a queue and ring the doorbell
275 * @nvmeq: The queue to use
276 * @cmd: The command to send
277 *
278 * Safe to use from interrupt context
279 */
280static int nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
281{
282	unsigned long flags;
283	u16 tail;
284	spin_lock_irqsave(&nvmeq->q_lock, flags);
285	tail = nvmeq->sq_tail;
286	memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
287	if (++tail == nvmeq->q_depth)
288		tail = 0;
289	writel(tail, nvmeq->q_db);
290	nvmeq->sq_tail = tail;
291	spin_unlock_irqrestore(&nvmeq->q_lock, flags);
292
293	return 0;
294}
295
296/*
297 * The nvme_iod describes the data in an I/O, including the list of PRP
298 * entries.  You can't see it in this data structure because C doesn't let
299 * me express that.  Use nvme_alloc_iod to ensure there's enough space
300 * allocated to store the PRP list.
301 */
302struct nvme_iod {
303	void *private;		/* For the use of the submitter of the I/O */
304	int npages;		/* In the PRP list. 0 means small pool in use */
305	int offset;		/* Of PRP list */
306	int nents;		/* Used in scatterlist */
307	int length;		/* Of data, in bytes */
308	dma_addr_t first_dma;
309	struct scatterlist sg[0];
310};
311
312static __le64 **iod_list(struct nvme_iod *iod)
313{
314	return ((void *)iod) + iod->offset;
315}
316
317/*
318 * Will slightly overestimate the number of pages needed.  This is OK
319 * as it only leads to a small amount of wasted memory for the lifetime of
320 * the I/O.
321 */
322static int nvme_npages(unsigned size)
323{
324	unsigned nprps = DIV_ROUND_UP(size + PAGE_SIZE, PAGE_SIZE);
325	return DIV_ROUND_UP(8 * nprps, PAGE_SIZE - 8);
326}
327
328static struct nvme_iod *
329nvme_alloc_iod(unsigned nseg, unsigned nbytes, gfp_t gfp)
330{
331	struct nvme_iod *iod = kmalloc(sizeof(struct nvme_iod) +
332				sizeof(__le64 *) * nvme_npages(nbytes) +
333				sizeof(struct scatterlist) * nseg, gfp);
334
335	if (iod) {
336		iod->offset = offsetof(struct nvme_iod, sg[nseg]);
337		iod->npages = -1;
338		iod->length = nbytes;
339	}
340
341	return iod;
342}
343
344static void nvme_free_iod(struct nvme_dev *dev, struct nvme_iod *iod)
345{
346	const int last_prp = PAGE_SIZE / 8 - 1;
347	int i;
348	__le64 **list = iod_list(iod);
349	dma_addr_t prp_dma = iod->first_dma;
350
351	if (iod->npages == 0)
352		dma_pool_free(dev->prp_small_pool, list[0], prp_dma);
353	for (i = 0; i < iod->npages; i++) {
354		__le64 *prp_list = list[i];
355		dma_addr_t next_prp_dma = le64_to_cpu(prp_list[last_prp]);
356		dma_pool_free(dev->prp_page_pool, prp_list, prp_dma);
357		prp_dma = next_prp_dma;
358	}
359	kfree(iod);
360}
361
362static void requeue_bio(struct nvme_dev *dev, struct bio *bio)
363{
364	struct nvme_queue *nvmeq = get_nvmeq(dev);
365	if (bio_list_empty(&nvmeq->sq_cong))
366		add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
367	bio_list_add(&nvmeq->sq_cong, bio);
368	put_nvmeq(nvmeq);
369	wake_up_process(nvme_thread);
370}
371
372static void bio_completion(struct nvme_dev *dev, void *ctx,
373						struct nvme_completion *cqe)
374{
375	struct nvme_iod *iod = ctx;
376	struct bio *bio = iod->private;
377	u16 status = le16_to_cpup(&cqe->status) >> 1;
378
379	dma_unmap_sg(&dev->pci_dev->dev, iod->sg, iod->nents,
380			bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
381	nvme_free_iod(dev, iod);
382	if (status) {
383		bio_endio(bio, -EIO);
384	} else if (bio->bi_vcnt > bio->bi_idx) {
385		requeue_bio(dev, bio);
386	} else {
387		bio_endio(bio, 0);
388	}
389}
390
391/* length is in bytes.  gfp flags indicates whether we may sleep. */
392static int nvme_setup_prps(struct nvme_dev *dev,
393			struct nvme_common_command *cmd, struct nvme_iod *iod,
394			int total_len, gfp_t gfp)
395{
396	struct dma_pool *pool;
397	int length = total_len;
398	struct scatterlist *sg = iod->sg;
399	int dma_len = sg_dma_len(sg);
400	u64 dma_addr = sg_dma_address(sg);
401	int offset = offset_in_page(dma_addr);
402	__le64 *prp_list;
403	__le64 **list = iod_list(iod);
404	dma_addr_t prp_dma;
405	int nprps, i;
406
407	cmd->prp1 = cpu_to_le64(dma_addr);
408	length -= (PAGE_SIZE - offset);
409	if (length <= 0)
410		return total_len;
411
412	dma_len -= (PAGE_SIZE - offset);
413	if (dma_len) {
414		dma_addr += (PAGE_SIZE - offset);
415	} else {
416		sg = sg_next(sg);
417		dma_addr = sg_dma_address(sg);
418		dma_len = sg_dma_len(sg);
419	}
420
421	if (length <= PAGE_SIZE) {
422		cmd->prp2 = cpu_to_le64(dma_addr);
423		return total_len;
424	}
425
426	nprps = DIV_ROUND_UP(length, PAGE_SIZE);
427	if (nprps <= (256 / 8)) {
428		pool = dev->prp_small_pool;
429		iod->npages = 0;
430	} else {
431		pool = dev->prp_page_pool;
432		iod->npages = 1;
433	}
434
435	prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
436	if (!prp_list) {
437		cmd->prp2 = cpu_to_le64(dma_addr);
438		iod->npages = -1;
439		return (total_len - length) + PAGE_SIZE;
440	}
441	list[0] = prp_list;
442	iod->first_dma = prp_dma;
443	cmd->prp2 = cpu_to_le64(prp_dma);
444	i = 0;
445	for (;;) {
446		if (i == PAGE_SIZE / 8) {
447			__le64 *old_prp_list = prp_list;
448			prp_list = dma_pool_alloc(pool, gfp, &prp_dma);
449			if (!prp_list)
450				return total_len - length;
451			list[iod->npages++] = prp_list;
452			prp_list[0] = old_prp_list[i - 1];
453			old_prp_list[i - 1] = cpu_to_le64(prp_dma);
454			i = 1;
455		}
456		prp_list[i++] = cpu_to_le64(dma_addr);
457		dma_len -= PAGE_SIZE;
458		dma_addr += PAGE_SIZE;
459		length -= PAGE_SIZE;
460		if (length <= 0)
461			break;
462		if (dma_len > 0)
463			continue;
464		BUG_ON(dma_len < 0);
465		sg = sg_next(sg);
466		dma_addr = sg_dma_address(sg);
467		dma_len = sg_dma_len(sg);
468	}
469
470	return total_len;
471}
472
473/* NVMe scatterlists require no holes in the virtual address */
474#define BIOVEC_NOT_VIRT_MERGEABLE(vec1, vec2)	((vec2)->bv_offset || \
475			(((vec1)->bv_offset + (vec1)->bv_len) % PAGE_SIZE))
476
477static int nvme_map_bio(struct device *dev, struct nvme_iod *iod,
478		struct bio *bio, enum dma_data_direction dma_dir, int psegs)
479{
480	struct bio_vec *bvec, *bvprv = NULL;
481	struct scatterlist *sg = NULL;
482	int i, old_idx, length = 0, nsegs = 0;
483
484	sg_init_table(iod->sg, psegs);
485	old_idx = bio->bi_idx;
486	bio_for_each_segment(bvec, bio, i) {
487		if (bvprv && BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) {
488			sg->length += bvec->bv_len;
489		} else {
490			if (bvprv && BIOVEC_NOT_VIRT_MERGEABLE(bvprv, bvec))
491				break;
492			sg = sg ? sg + 1 : iod->sg;
493			sg_set_page(sg, bvec->bv_page, bvec->bv_len,
494							bvec->bv_offset);
495			nsegs++;
496		}
497		length += bvec->bv_len;
498		bvprv = bvec;
499	}
500	bio->bi_idx = i;
501	iod->nents = nsegs;
502	sg_mark_end(sg);
503	if (dma_map_sg(dev, iod->sg, iod->nents, dma_dir) == 0) {
504		bio->bi_idx = old_idx;
505		return -ENOMEM;
506	}
507	return length;
508}
509
510static int nvme_submit_flush(struct nvme_queue *nvmeq, struct nvme_ns *ns,
511								int cmdid)
512{
513	struct nvme_command *cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
514
515	memset(cmnd, 0, sizeof(*cmnd));
516	cmnd->common.opcode = nvme_cmd_flush;
517	cmnd->common.command_id = cmdid;
518	cmnd->common.nsid = cpu_to_le32(ns->ns_id);
519
520	if (++nvmeq->sq_tail == nvmeq->q_depth)
521		nvmeq->sq_tail = 0;
522	writel(nvmeq->sq_tail, nvmeq->q_db);
523
524	return 0;
525}
526
527static int nvme_submit_flush_data(struct nvme_queue *nvmeq, struct nvme_ns *ns)
528{
529	int cmdid = alloc_cmdid(nvmeq, (void *)CMD_CTX_FLUSH,
530					special_completion, NVME_IO_TIMEOUT);
531	if (unlikely(cmdid < 0))
532		return cmdid;
533
534	return nvme_submit_flush(nvmeq, ns, cmdid);
535}
536
537/*
538 * Called with local interrupts disabled and the q_lock held.  May not sleep.
539 */
540static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
541								struct bio *bio)
542{
543	struct nvme_command *cmnd;
544	struct nvme_iod *iod;
545	enum dma_data_direction dma_dir;
546	int cmdid, length, result = -ENOMEM;
547	u16 control;
548	u32 dsmgmt;
549	int psegs = bio_phys_segments(ns->queue, bio);
550
551	if ((bio->bi_rw & REQ_FLUSH) && psegs) {
552		result = nvme_submit_flush_data(nvmeq, ns);
553		if (result)
554			return result;
555	}
556
557	iod = nvme_alloc_iod(psegs, bio->bi_size, GFP_ATOMIC);
558	if (!iod)
559		goto nomem;
560	iod->private = bio;
561
562	result = -EBUSY;
563	cmdid = alloc_cmdid(nvmeq, iod, bio_completion, NVME_IO_TIMEOUT);
564	if (unlikely(cmdid < 0))
565		goto free_iod;
566
567	if ((bio->bi_rw & REQ_FLUSH) && !psegs)
568		return nvme_submit_flush(nvmeq, ns, cmdid);
569
570	control = 0;
571	if (bio->bi_rw & REQ_FUA)
572		control |= NVME_RW_FUA;
573	if (bio->bi_rw & (REQ_FAILFAST_DEV | REQ_RAHEAD))
574		control |= NVME_RW_LR;
575
576	dsmgmt = 0;
577	if (bio->bi_rw & REQ_RAHEAD)
578		dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
579
580	cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
581
582	memset(cmnd, 0, sizeof(*cmnd));
583	if (bio_data_dir(bio)) {
584		cmnd->rw.opcode = nvme_cmd_write;
585		dma_dir = DMA_TO_DEVICE;
586	} else {
587		cmnd->rw.opcode = nvme_cmd_read;
588		dma_dir = DMA_FROM_DEVICE;
589	}
590
591	result = nvme_map_bio(nvmeq->q_dmadev, iod, bio, dma_dir, psegs);
592	if (result < 0)
593		goto free_cmdid;
594	length = result;
595
596	cmnd->rw.command_id = cmdid;
597	cmnd->rw.nsid = cpu_to_le32(ns->ns_id);
598	length = nvme_setup_prps(nvmeq->dev, &cmnd->common, iod, length,
599								GFP_ATOMIC);
600	cmnd->rw.slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));
601	cmnd->rw.length = cpu_to_le16((length >> ns->lba_shift) - 1);
602	cmnd->rw.control = cpu_to_le16(control);
603	cmnd->rw.dsmgmt = cpu_to_le32(dsmgmt);
604
605	bio->bi_sector += length >> 9;
606
607	if (++nvmeq->sq_tail == nvmeq->q_depth)
608		nvmeq->sq_tail = 0;
609	writel(nvmeq->sq_tail, nvmeq->q_db);
610
611	return 0;
612
613 free_cmdid:
614	free_cmdid(nvmeq, cmdid, NULL);
615 free_iod:
616	nvme_free_iod(nvmeq->dev, iod);
617 nomem:
618	return result;
619}
620
621static void nvme_make_request(struct request_queue *q, struct bio *bio)
622{
623	struct nvme_ns *ns = q->queuedata;
624	struct nvme_queue *nvmeq = get_nvmeq(ns->dev);
625	int result = -EBUSY;
626
627	spin_lock_irq(&nvmeq->q_lock);
628	if (bio_list_empty(&nvmeq->sq_cong))
629		result = nvme_submit_bio_queue(nvmeq, ns, bio);
630	if (unlikely(result)) {
631		if (bio_list_empty(&nvmeq->sq_cong))
632			add_wait_queue(&nvmeq->sq_full, &nvmeq->sq_cong_wait);
633		bio_list_add(&nvmeq->sq_cong, bio);
634	}
635
636	spin_unlock_irq(&nvmeq->q_lock);
637	put_nvmeq(nvmeq);
638}
639
640static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
641{
642	u16 head, phase;
643
644	head = nvmeq->cq_head;
645	phase = nvmeq->cq_phase;
646
647	for (;;) {
648		void *ctx;
649		nvme_completion_fn fn;
650		struct nvme_completion cqe = nvmeq->cqes[head];
651		if ((le16_to_cpu(cqe.status) & 1) != phase)
652			break;
653		nvmeq->sq_head = le16_to_cpu(cqe.sq_head);
654		if (++head == nvmeq->q_depth) {
655			head = 0;
656			phase = !phase;
657		}
658
659		ctx = free_cmdid(nvmeq, cqe.command_id, &fn);
660		fn(nvmeq->dev, ctx, &cqe);
661	}
662
663	/* If the controller ignores the cq head doorbell and continuously
664	 * writes to the queue, it is theoretically possible to wrap around
665	 * the queue twice and mistakenly return IRQ_NONE.  Linux only
666	 * requires that 0.1% of your interrupts are handled, so this isn't
667	 * a big problem.
668	 */
669	if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
670		return IRQ_NONE;
671
672	writel(head, nvmeq->q_db + (1 << nvmeq->dev->db_stride));
673	nvmeq->cq_head = head;
674	nvmeq->cq_phase = phase;
675
676	return IRQ_HANDLED;
677}
678
679static irqreturn_t nvme_irq(int irq, void *data)
680{
681	irqreturn_t result;
682	struct nvme_queue *nvmeq = data;
683	spin_lock(&nvmeq->q_lock);
684	result = nvme_process_cq(nvmeq);
685	spin_unlock(&nvmeq->q_lock);
686	return result;
687}
688
689static irqreturn_t nvme_irq_check(int irq, void *data)
690{
691	struct nvme_queue *nvmeq = data;
692	struct nvme_completion cqe = nvmeq->cqes[nvmeq->cq_head];
693	if ((le16_to_cpu(cqe.status) & 1) != nvmeq->cq_phase)
694		return IRQ_NONE;
695	return IRQ_WAKE_THREAD;
696}
697
698static void nvme_abort_command(struct nvme_queue *nvmeq, int cmdid)
699{
700	spin_lock_irq(&nvmeq->q_lock);
701	cancel_cmdid(nvmeq, cmdid, NULL);
702	spin_unlock_irq(&nvmeq->q_lock);
703}
704
705struct sync_cmd_info {
706	struct task_struct *task;
707	u32 result;
708	int status;
709};
710
711static void sync_completion(struct nvme_dev *dev, void *ctx,
712						struct nvme_completion *cqe)
713{
714	struct sync_cmd_info *cmdinfo = ctx;
715	cmdinfo->result = le32_to_cpup(&cqe->result);
716	cmdinfo->status = le16_to_cpup(&cqe->status) >> 1;
717	wake_up_process(cmdinfo->task);
718}
719
720/*
721 * Returns 0 on success.  If the result is negative, it's a Linux error code;
722 * if the result is positive, it's an NVM Express status code
723 */
724static int nvme_submit_sync_cmd(struct nvme_queue *nvmeq,
725			struct nvme_command *cmd, u32 *result, unsigned timeout)
726{
727	int cmdid;
728	struct sync_cmd_info cmdinfo;
729
730	cmdinfo.task = current;
731	cmdinfo.status = -EINTR;
732
733	cmdid = alloc_cmdid_killable(nvmeq, &cmdinfo, sync_completion,
734								timeout);
735	if (cmdid < 0)
736		return cmdid;
737	cmd->common.command_id = cmdid;
738
739	set_current_state(TASK_KILLABLE);
740	nvme_submit_cmd(nvmeq, cmd);
741	schedule();
742
743	if (cmdinfo.status == -EINTR) {
744		nvme_abort_command(nvmeq, cmdid);
745		return -EINTR;
746	}
747
748	if (result)
749		*result = cmdinfo.result;
750
751	return cmdinfo.status;
752}
753
754static int nvme_submit_admin_cmd(struct nvme_dev *dev, struct nvme_command *cmd,
755								u32 *result)
756{
757	return nvme_submit_sync_cmd(dev->queues[0], cmd, result, ADMIN_TIMEOUT);
758}
759
760static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
761{
762	int status;
763	struct nvme_command c;
764
765	memset(&c, 0, sizeof(c));
766	c.delete_queue.opcode = opcode;
767	c.delete_queue.qid = cpu_to_le16(id);
768
769	status = nvme_submit_admin_cmd(dev, &c, NULL);
770	if (status)
771		return -EIO;
772	return 0;
773}
774
775static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
776						struct nvme_queue *nvmeq)
777{
778	int status;
779	struct nvme_command c;
780	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
781
782	memset(&c, 0, sizeof(c));
783	c.create_cq.opcode = nvme_admin_create_cq;
784	c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
785	c.create_cq.cqid = cpu_to_le16(qid);
786	c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
787	c.create_cq.cq_flags = cpu_to_le16(flags);
788	c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
789
790	status = nvme_submit_admin_cmd(dev, &c, NULL);
791	if (status)
792		return -EIO;
793	return 0;
794}
795
796static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
797						struct nvme_queue *nvmeq)
798{
799	int status;
800	struct nvme_command c;
801	int flags = NVME_QUEUE_PHYS_CONTIG | NVME_SQ_PRIO_MEDIUM;
802
803	memset(&c, 0, sizeof(c));
804	c.create_sq.opcode = nvme_admin_create_sq;
805	c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
806	c.create_sq.sqid = cpu_to_le16(qid);
807	c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
808	c.create_sq.sq_flags = cpu_to_le16(flags);
809	c.create_sq.cqid = cpu_to_le16(qid);
810
811	status = nvme_submit_admin_cmd(dev, &c, NULL);
812	if (status)
813		return -EIO;
814	return 0;
815}
816
817static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
818{
819	return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
820}
821
822static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
823{
824	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
825}
826
827static int nvme_identify(struct nvme_dev *dev, unsigned nsid, unsigned cns,
828							dma_addr_t dma_addr)
829{
830	struct nvme_command c;
831
832	memset(&c, 0, sizeof(c));
833	c.identify.opcode = nvme_admin_identify;
834	c.identify.nsid = cpu_to_le32(nsid);
835	c.identify.prp1 = cpu_to_le64(dma_addr);
836	c.identify.cns = cpu_to_le32(cns);
837
838	return nvme_submit_admin_cmd(dev, &c, NULL);
839}
840
841static int nvme_get_features(struct nvme_dev *dev, unsigned fid, unsigned nsid,
842					dma_addr_t dma_addr, u32 *result)
843{
844	struct nvme_command c;
845
846	memset(&c, 0, sizeof(c));
847	c.features.opcode = nvme_admin_get_features;
848	c.features.nsid = cpu_to_le32(nsid);
849	c.features.prp1 = cpu_to_le64(dma_addr);
850	c.features.fid = cpu_to_le32(fid);
851
852	return nvme_submit_admin_cmd(dev, &c, result);
853}
854
855static int nvme_set_features(struct nvme_dev *dev, unsigned fid,
856			unsigned dword11, dma_addr_t dma_addr, u32 *result)
857{
858	struct nvme_command c;
859
860	memset(&c, 0, sizeof(c));
861	c.features.opcode = nvme_admin_set_features;
862	c.features.prp1 = cpu_to_le64(dma_addr);
863	c.features.fid = cpu_to_le32(fid);
864	c.features.dword11 = cpu_to_le32(dword11);
865
866	return nvme_submit_admin_cmd(dev, &c, result);
867}
868
869/**
870 * nvme_cancel_ios - Cancel outstanding I/Os
871 * @queue: The queue to cancel I/Os on
872 * @timeout: True to only cancel I/Os which have timed out
873 */
874static void nvme_cancel_ios(struct nvme_queue *nvmeq, bool timeout)
875{
876	int depth = nvmeq->q_depth - 1;
877	struct nvme_cmd_info *info = nvme_cmd_info(nvmeq);
878	unsigned long now = jiffies;
879	int cmdid;
880
881	for_each_set_bit(cmdid, nvmeq->cmdid_data, depth) {
882		void *ctx;
883		nvme_completion_fn fn;
884		static struct nvme_completion cqe = {
885			.status = cpu_to_le16(NVME_SC_ABORT_REQ) << 1,
886		};
887
888		if (timeout && !time_after(now, info[cmdid].timeout))
889			continue;
890		dev_warn(nvmeq->q_dmadev, "Cancelling I/O %d\n", cmdid);
891		ctx = cancel_cmdid(nvmeq, cmdid, &fn);
892		fn(nvmeq->dev, ctx, &cqe);
893	}
894}
895
896static void nvme_free_queue_mem(struct nvme_queue *nvmeq)
897{
898	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
899				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
900	dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
901					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
902	kfree(nvmeq);
903}
904
905static void nvme_free_queue(struct nvme_dev *dev, int qid)
906{
907	struct nvme_queue *nvmeq = dev->queues[qid];
908	int vector = dev->entry[nvmeq->cq_vector].vector;
909
910	spin_lock_irq(&nvmeq->q_lock);
911	nvme_cancel_ios(nvmeq, false);
912	while (bio_list_peek(&nvmeq->sq_cong)) {
913		struct bio *bio = bio_list_pop(&nvmeq->sq_cong);
914		bio_endio(bio, -EIO);
915	}
916	spin_unlock_irq(&nvmeq->q_lock);
917
918	irq_set_affinity_hint(vector, NULL);
919	free_irq(vector, nvmeq);
920
921	/* Don't tell the adapter to delete the admin queue */
922	if (qid) {
923		adapter_delete_sq(dev, qid);
924		adapter_delete_cq(dev, qid);
925	}
926
927	nvme_free_queue_mem(nvmeq);
928}
929
930static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
931							int depth, int vector)
932{
933	struct device *dmadev = &dev->pci_dev->dev;
934	unsigned extra = DIV_ROUND_UP(depth, 8) + (depth *
935						sizeof(struct nvme_cmd_info));
936	struct nvme_queue *nvmeq = kzalloc(sizeof(*nvmeq) + extra, GFP_KERNEL);
937	if (!nvmeq)
938		return NULL;
939
940	nvmeq->cqes = dma_alloc_coherent(dmadev, CQ_SIZE(depth),
941					&nvmeq->cq_dma_addr, GFP_KERNEL);
942	if (!nvmeq->cqes)
943		goto free_nvmeq;
944	memset((void *)nvmeq->cqes, 0, CQ_SIZE(depth));
945
946	nvmeq->sq_cmds = dma_alloc_coherent(dmadev, SQ_SIZE(depth),
947					&nvmeq->sq_dma_addr, GFP_KERNEL);
948	if (!nvmeq->sq_cmds)
949		goto free_cqdma;
950
951	nvmeq->q_dmadev = dmadev;
952	nvmeq->dev = dev;
953	spin_lock_init(&nvmeq->q_lock);
954	nvmeq->cq_head = 0;
955	nvmeq->cq_phase = 1;
956	init_waitqueue_head(&nvmeq->sq_full);
957	init_waitqueue_entry(&nvmeq->sq_cong_wait, nvme_thread);
958	bio_list_init(&nvmeq->sq_cong);
959	nvmeq->q_db = &dev->dbs[qid << (dev->db_stride + 1)];
960	nvmeq->q_depth = depth;
961	nvmeq->cq_vector = vector;
962
963	return nvmeq;
964
965 free_cqdma:
966	dma_free_coherent(dmadev, CQ_SIZE(nvmeq->q_depth), (void *)nvmeq->cqes,
967							nvmeq->cq_dma_addr);
968 free_nvmeq:
969	kfree(nvmeq);
970	return NULL;
971}
972
973static int queue_request_irq(struct nvme_dev *dev, struct nvme_queue *nvmeq,
974							const char *name)
975{
976	if (use_threaded_interrupts)
977		return request_threaded_irq(dev->entry[nvmeq->cq_vector].vector,
978					nvme_irq_check, nvme_irq,
979					IRQF_DISABLED | IRQF_SHARED,
980					name, nvmeq);
981	return request_irq(dev->entry[nvmeq->cq_vector].vector, nvme_irq,
982				IRQF_DISABLED | IRQF_SHARED, name, nvmeq);
983}
984
985static __devinit struct nvme_queue *nvme_create_queue(struct nvme_dev *dev,
986					int qid, int cq_size, int vector)
987{
988	int result;
989	struct nvme_queue *nvmeq = nvme_alloc_queue(dev, qid, cq_size, vector);
990
991	if (!nvmeq)
992		return ERR_PTR(-ENOMEM);
993
994	result = adapter_alloc_cq(dev, qid, nvmeq);
995	if (result < 0)
996		goto free_nvmeq;
997
998	result = adapter_alloc_sq(dev, qid, nvmeq);
999	if (result < 0)
1000		goto release_cq;
1001
1002	result = queue_request_irq(dev, nvmeq, "nvme");
1003	if (result < 0)
1004		goto release_sq;
1005
1006	return nvmeq;
1007
1008 release_sq:
1009	adapter_delete_sq(dev, qid);
1010 release_cq:
1011	adapter_delete_cq(dev, qid);
1012 free_nvmeq:
1013	dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
1014				(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
1015	dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
1016					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
1017	kfree(nvmeq);
1018	return ERR_PTR(result);
1019}
1020
1021static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
1022{
1023	int result = 0;
1024	u32 aqa;
1025	u64 cap;
1026	unsigned long timeout;
1027	struct nvme_queue *nvmeq;
1028
1029	dev->dbs = ((void __iomem *)dev->bar) + 4096;
1030
1031	nvmeq = nvme_alloc_queue(dev, 0, 64, 0);
1032	if (!nvmeq)
1033		return -ENOMEM;
1034
1035	aqa = nvmeq->q_depth - 1;
1036	aqa |= aqa << 16;
1037
1038	dev->ctrl_config = NVME_CC_ENABLE | NVME_CC_CSS_NVM;
1039	dev->ctrl_config |= (PAGE_SHIFT - 12) << NVME_CC_MPS_SHIFT;
1040	dev->ctrl_config |= NVME_CC_ARB_RR | NVME_CC_SHN_NONE;
1041	dev->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;
1042
1043	writel(0, &dev->bar->cc);
1044	writel(aqa, &dev->bar->aqa);
1045	writeq(nvmeq->sq_dma_addr, &dev->bar->asq);
1046	writeq(nvmeq->cq_dma_addr, &dev->bar->acq);
1047	writel(dev->ctrl_config, &dev->bar->cc);
1048
1049	cap = readq(&dev->bar->cap);
1050	timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
1051	dev->db_stride = NVME_CAP_STRIDE(cap);
1052
1053	while (!result && !(readl(&dev->bar->csts) & NVME_CSTS_RDY)) {
1054		msleep(100);
1055		if (fatal_signal_pending(current))
1056			result = -EINTR;
1057		if (time_after(jiffies, timeout)) {
1058			dev_err(&dev->pci_dev->dev,
1059				"Device not ready; aborting initialisation\n");
1060			result = -ENODEV;
1061		}
1062	}
1063
1064	if (result) {
1065		nvme_free_queue_mem(nvmeq);
1066		return result;
1067	}
1068
1069	result = queue_request_irq(dev, nvmeq, "nvme admin");
1070	dev->queues[0] = nvmeq;
1071	return result;
1072}
1073
1074static struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write,
1075				unsigned long addr, unsigned length)
1076{
1077	int i, err, count, nents, offset;
1078	struct scatterlist *sg;
1079	struct page **pages;
1080	struct nvme_iod *iod;
1081
1082	if (addr & 3)
1083		return ERR_PTR(-EINVAL);
1084	if (!length)
1085		return ERR_PTR(-EINVAL);
1086
1087	offset = offset_in_page(addr);
1088	count = DIV_ROUND_UP(offset + length, PAGE_SIZE);
1089	pages = kcalloc(count, sizeof(*pages), GFP_KERNEL);
1090	if (!pages)
1091		return ERR_PTR(-ENOMEM);
1092
1093	err = get_user_pages_fast(addr, count, 1, pages);
1094	if (err < count) {
1095		count = err;
1096		err = -EFAULT;
1097		goto put_pages;
1098	}
1099
1100	iod = nvme_alloc_iod(count, length, GFP_KERNEL);
1101	sg = iod->sg;
1102	sg_init_table(sg, count);
1103	for (i = 0; i < count; i++) {
1104		sg_set_page(&sg[i], pages[i],
1105				min_t(int, length, PAGE_SIZE - offset), offset);
1106		length -= (PAGE_SIZE - offset);
1107		offset = 0;
1108	}
1109	sg_mark_end(&sg[i - 1]);
1110	iod->nents = count;
1111
1112	err = -ENOMEM;
1113	nents = dma_map_sg(&dev->pci_dev->dev, sg, count,
1114				write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
1115	if (!nents)
1116		goto free_iod;
1117
1118	kfree(pages);
1119	return iod;
1120
1121 free_iod:
1122	kfree(iod);
1123 put_pages:
1124	for (i = 0; i < count; i++)
1125		put_page(pages[i]);
1126	kfree(pages);
1127	return ERR_PTR(err);
1128}
1129
1130static void nvme_unmap_user_pages(struct nvme_dev *dev, int write,
1131			struct nvme_iod *iod)
1132{
1133	int i;
1134
1135	dma_unmap_sg(&dev->pci_dev->dev, iod->sg, iod->nents,
1136				write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
1137
1138	for (i = 0; i < iod->nents; i++)
1139		put_page(sg_page(&iod->sg[i]));
1140}
1141
1142static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
1143{
1144	struct nvme_dev *dev = ns->dev;
1145	struct nvme_queue *nvmeq;
1146	struct nvme_user_io io;
1147	struct nvme_command c;
1148	unsigned length;
1149	int status;
1150	struct nvme_iod *iod;
1151
1152	if (copy_from_user(&io, uio, sizeof(io)))
1153		return -EFAULT;
1154	length = (io.nblocks + 1) << ns->lba_shift;
1155
1156	switch (io.opcode) {
1157	case nvme_cmd_write:
1158	case nvme_cmd_read:
1159	case nvme_cmd_compare:
1160		iod = nvme_map_user_pages(dev, io.opcode & 1, io.addr, length);
1161		break;
1162	default:
1163		return -EINVAL;
1164	}
1165
1166	if (IS_ERR(iod))
1167		return PTR_ERR(iod);
1168
1169	memset(&c, 0, sizeof(c));
1170	c.rw.opcode = io.opcode;
1171	c.rw.flags = io.flags;
1172	c.rw.nsid = cpu_to_le32(ns->ns_id);
1173	c.rw.slba = cpu_to_le64(io.slba);
1174	c.rw.length = cpu_to_le16(io.nblocks);
1175	c.rw.control = cpu_to_le16(io.control);
1176	c.rw.dsmgmt = cpu_to_le16(io.dsmgmt);
1177	c.rw.reftag = io.reftag;
1178	c.rw.apptag = io.apptag;
1179	c.rw.appmask = io.appmask;
1180	/* XXX: metadata */
1181	length = nvme_setup_prps(dev, &c.common, iod, length, GFP_KERNEL);
1182
1183	nvmeq = get_nvmeq(dev);
1184	/*
1185	 * Since nvme_submit_sync_cmd sleeps, we can't keep preemption
1186	 * disabled.  We may be preempted at any point, and be rescheduled
1187	 * to a different CPU.  That will cause cacheline bouncing, but no
1188	 * additional races since q_lock already protects against other CPUs.
1189	 */
1190	put_nvmeq(nvmeq);
1191	if (length != (io.nblocks + 1) << ns->lba_shift)
1192		status = -ENOMEM;
1193	else
1194		status = nvme_submit_sync_cmd(nvmeq, &c, NULL, NVME_IO_TIMEOUT);
1195
1196	nvme_unmap_user_pages(dev, io.opcode & 1, iod);
1197	nvme_free_iod(dev, iod);
1198	return status;
1199}
1200
1201static int nvme_user_admin_cmd(struct nvme_dev *dev,
1202					struct nvme_admin_cmd __user *ucmd)
1203{
1204	struct nvme_admin_cmd cmd;
1205	struct nvme_command c;
1206	int status, length;
1207	struct nvme_iod *uninitialized_var(iod);
1208
1209	if (!capable(CAP_SYS_ADMIN))
1210		return -EACCES;
1211	if (copy_from_user(&cmd, ucmd, sizeof(cmd)))
1212		return -EFAULT;
1213
1214	memset(&c, 0, sizeof(c));
1215	c.common.opcode = cmd.opcode;
1216	c.common.flags = cmd.flags;
1217	c.common.nsid = cpu_to_le32(cmd.nsid);
1218	c.common.cdw2[0] = cpu_to_le32(cmd.cdw2);
1219	c.common.cdw2[1] = cpu_to_le32(cmd.cdw3);
1220	c.common.cdw10[0] = cpu_to_le32(cmd.cdw10);
1221	c.common.cdw10[1] = cpu_to_le32(cmd.cdw11);
1222	c.common.cdw10[2] = cpu_to_le32(cmd.cdw12);
1223	c.common.cdw10[3] = cpu_to_le32(cmd.cdw13);
1224	c.common.cdw10[4] = cpu_to_le32(cmd.cdw14);
1225	c.common.cdw10[5] = cpu_to_le32(cmd.cdw15);
1226
1227	length = cmd.data_len;
1228	if (cmd.data_len) {
1229		iod = nvme_map_user_pages(dev, cmd.opcode & 1, cmd.addr,
1230								length);
1231		if (IS_ERR(iod))
1232			return PTR_ERR(iod);
1233		length = nvme_setup_prps(dev, &c.common, iod, length,
1234								GFP_KERNEL);
1235	}
1236
1237	if (length != cmd.data_len)
1238		status = -ENOMEM;
1239	else
1240		status = nvme_submit_admin_cmd(dev, &c, &cmd.result);
1241
1242	if (cmd.data_len) {
1243		nvme_unmap_user_pages(dev, cmd.opcode & 1, iod);
1244		nvme_free_iod(dev, iod);
1245	}
1246
1247	if (!status && copy_to_user(&ucmd->result, &cmd.result,
1248							sizeof(cmd.result)))
1249		status = -EFAULT;
1250
1251	return status;
1252}
1253
1254static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
1255							unsigned long arg)
1256{
1257	struct nvme_ns *ns = bdev->bd_disk->private_data;
1258
1259	switch (cmd) {
1260	case NVME_IOCTL_ID:
1261		return ns->ns_id;
1262	case NVME_IOCTL_ADMIN_CMD:
1263		return nvme_user_admin_cmd(ns->dev, (void __user *)arg);
1264	case NVME_IOCTL_SUBMIT_IO:
1265		return nvme_submit_io(ns, (void __user *)arg);
1266	default:
1267		return -ENOTTY;
1268	}
1269}
1270
1271static const struct block_device_operations nvme_fops = {
1272	.owner		= THIS_MODULE,
1273	.ioctl		= nvme_ioctl,
1274	.compat_ioctl	= nvme_ioctl,
1275};
1276
1277static void nvme_resubmit_bios(struct nvme_queue *nvmeq)
1278{
1279	while (bio_list_peek(&nvmeq->sq_cong)) {
1280		struct bio *bio = bio_list_pop(&nvmeq->sq_cong);
1281		struct nvme_ns *ns = bio->bi_bdev->bd_disk->private_data;
1282		if (nvme_submit_bio_queue(nvmeq, ns, bio)) {
1283			bio_list_add_head(&nvmeq->sq_cong, bio);
1284			break;
1285		}
1286		if (bio_list_empty(&nvmeq->sq_cong))
1287			remove_wait_queue(&nvmeq->sq_full,
1288							&nvmeq->sq_cong_wait);
1289	}
1290}
1291
1292static int nvme_kthread(void *data)
1293{
1294	struct nvme_dev *dev;
1295
1296	while (!kthread_should_stop()) {
1297		__set_current_state(TASK_RUNNING);
1298		spin_lock(&dev_list_lock);
1299		list_for_each_entry(dev, &dev_list, node) {
1300			int i;
1301			for (i = 0; i < dev->queue_count; i++) {
1302				struct nvme_queue *nvmeq = dev->queues[i];
1303				if (!nvmeq)
1304					continue;
1305				spin_lock_irq(&nvmeq->q_lock);
1306				if (nvme_process_cq(nvmeq))
1307					printk("process_cq did something\n");
1308				nvme_cancel_ios(nvmeq, true);
1309				nvme_resubmit_bios(nvmeq);
1310				spin_unlock_irq(&nvmeq->q_lock);
1311			}
1312		}
1313		spin_unlock(&dev_list_lock);
1314		set_current_state(TASK_INTERRUPTIBLE);
1315		schedule_timeout(HZ);
1316	}
1317	return 0;
1318}
1319
1320static DEFINE_IDA(nvme_index_ida);
1321
1322static int nvme_get_ns_idx(void)
1323{
1324	int index, error;
1325
1326	do {
1327		if (!ida_pre_get(&nvme_index_ida, GFP_KERNEL))
1328			return -1;
1329
1330		spin_lock(&dev_list_lock);
1331		error = ida_get_new(&nvme_index_ida, &index);
1332		spin_unlock(&dev_list_lock);
1333	} while (error == -EAGAIN);
1334
1335	if (error)
1336		index = -1;
1337	return index;
1338}
1339
1340static void nvme_put_ns_idx(int index)
1341{
1342	spin_lock(&dev_list_lock);
1343	ida_remove(&nvme_index_ida, index);
1344	spin_unlock(&dev_list_lock);
1345}
1346
1347static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid,
1348			struct nvme_id_ns *id, struct nvme_lba_range_type *rt)
1349{
1350	struct nvme_ns *ns;
1351	struct gendisk *disk;
1352	int lbaf;
1353
1354	if (rt->attributes & NVME_LBART_ATTRIB_HIDE)
1355		return NULL;
1356
1357	ns = kzalloc(sizeof(*ns), GFP_KERNEL);
1358	if (!ns)
1359		return NULL;
1360	ns->queue = blk_alloc_queue(GFP_KERNEL);
1361	if (!ns->queue)
1362		goto out_free_ns;
1363	ns->queue->queue_flags = QUEUE_FLAG_DEFAULT;
1364	queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, ns->queue);
1365	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, ns->queue);
1366/*	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue); */
1367	blk_queue_make_request(ns->queue, nvme_make_request);
1368	ns->dev = dev;
1369	ns->queue->queuedata = ns;
1370
1371	disk = alloc_disk(NVME_MINORS);
1372	if (!disk)
1373		goto out_free_queue;
1374	ns->ns_id = nsid;
1375	ns->disk = disk;
1376	lbaf = id->flbas & 0xf;
1377	ns->lba_shift = id->lbaf[lbaf].ds;
1378	blk_queue_logical_block_size(ns->queue, 1 << ns->lba_shift);
1379	if (dev->max_hw_sectors)
1380		blk_queue_max_hw_sectors(ns->queue, dev->max_hw_sectors);
1381
1382	disk->major = nvme_major;
1383	disk->minors = NVME_MINORS;
1384	disk->first_minor = NVME_MINORS * nvme_get_ns_idx();
1385	disk->fops = &nvme_fops;
1386	disk->private_data = ns;
1387	disk->queue = ns->queue;
1388	disk->driverfs_dev = &dev->pci_dev->dev;
1389	sprintf(disk->disk_name, "nvme%dn%d", dev->instance, nsid);
1390	set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
1391
1392	return ns;
1393
1394 out_free_queue:
1395	blk_cleanup_queue(ns->queue);
1396 out_free_ns:
1397	kfree(ns);
1398	return NULL;
1399}
1400
1401static void nvme_ns_free(struct nvme_ns *ns)
1402{
1403	int index = ns->disk->first_minor / NVME_MINORS;
1404	put_disk(ns->disk);
1405	nvme_put_ns_idx(index);
1406	blk_cleanup_queue(ns->queue);
1407	kfree(ns);
1408}
1409
1410static int set_queue_count(struct nvme_dev *dev, int count)
1411{
1412	int status;
1413	u32 result;
1414	u32 q_count = (count - 1) | ((count - 1) << 16);
1415
1416	status = nvme_set_features(dev, NVME_FEAT_NUM_QUEUES, q_count, 0,
1417								&result);
1418	if (status)
1419		return -EIO;
1420	return min(result & 0xffff, result >> 16) + 1;
1421}
1422
1423static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
1424{
1425	int result, cpu, i, nr_io_queues, db_bar_size, q_depth;
1426
1427	nr_io_queues = num_online_cpus();
1428	result = set_queue_count(dev, nr_io_queues);
1429	if (result < 0)
1430		return result;
1431	if (result < nr_io_queues)
1432		nr_io_queues = result;
1433
1434	/* Deregister the admin queue's interrupt */
1435	free_irq(dev->entry[0].vector, dev->queues[0]);
1436
1437	db_bar_size = 4096 + ((nr_io_queues + 1) << (dev->db_stride + 3));
1438	if (db_bar_size > 8192) {
1439		iounmap(dev->bar);
1440		dev->bar = ioremap(pci_resource_start(dev->pci_dev, 0),
1441								db_bar_size);
1442		dev->dbs = ((void __iomem *)dev->bar) + 4096;
1443		dev->queues[0]->q_db = dev->dbs;
1444	}
1445
1446	for (i = 0; i < nr_io_queues; i++)
1447		dev->entry[i].entry = i;
1448	for (;;) {
1449		result = pci_enable_msix(dev->pci_dev, dev->entry,
1450								nr_io_queues);
1451		if (result == 0) {
1452			break;
1453		} else if (result > 0) {
1454			nr_io_queues = result;
1455			continue;
1456		} else {
1457			nr_io_queues = 1;
1458			break;
1459		}
1460	}
1461
1462	result = queue_request_irq(dev, dev->queues[0], "nvme admin");
1463	/* XXX: handle failure here */
1464
1465	cpu = cpumask_first(cpu_online_mask);
1466	for (i = 0; i < nr_io_queues; i++) {
1467		irq_set_affinity_hint(dev->entry[i].vector, get_cpu_mask(cpu));
1468		cpu = cpumask_next(cpu, cpu_online_mask);
1469	}
1470
1471	q_depth = min_t(int, NVME_CAP_MQES(readq(&dev->bar->cap)) + 1,
1472								NVME_Q_DEPTH);
1473	for (i = 0; i < nr_io_queues; i++) {
1474		dev->queues[i + 1] = nvme_create_queue(dev, i + 1, q_depth, i);
1475		if (IS_ERR(dev->queues[i + 1]))
1476			return PTR_ERR(dev->queues[i + 1]);
1477		dev->queue_count++;
1478	}
1479
1480	for (; i < num_possible_cpus(); i++) {
1481		int target = i % rounddown_pow_of_two(dev->queue_count - 1);
1482		dev->queues[i + 1] = dev->queues[target + 1];
1483	}
1484
1485	return 0;
1486}
1487
1488static void nvme_free_queues(struct nvme_dev *dev)
1489{
1490	int i;
1491
1492	for (i = dev->queue_count - 1; i >= 0; i--)
1493		nvme_free_queue(dev, i);
1494}
1495
1496static int __devinit nvme_dev_add(struct nvme_dev *dev)
1497{
1498	int res, nn, i;
1499	struct nvme_ns *ns, *next;
1500	struct nvme_id_ctrl *ctrl;
1501	struct nvme_id_ns *id_ns;
1502	void *mem;
1503	dma_addr_t dma_addr;
1504
1505	res = nvme_setup_io_queues(dev);
1506	if (res)
1507		return res;
1508
1509	mem = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
1510								GFP_KERNEL);
1511
1512	res = nvme_identify(dev, 0, 1, dma_addr);
1513	if (res) {
1514		res = -EIO;
1515		goto out_free;
1516	}
1517
1518	ctrl = mem;
1519	nn = le32_to_cpup(&ctrl->nn);
1520	memcpy(dev->serial, ctrl->sn, sizeof(ctrl->sn));
1521	memcpy(dev->model, ctrl->mn, sizeof(ctrl->mn));
1522	memcpy(dev->firmware_rev, ctrl->fr, sizeof(ctrl->fr));
1523	if (ctrl->mdts) {
1524		int shift = NVME_CAP_MPSMIN(readq(&dev->bar->cap)) + 12;
1525		dev->max_hw_sectors = 1 << (ctrl->mdts + shift - 9);
1526	}
1527
1528	id_ns = mem;
1529	for (i = 1; i <= nn; i++) {
1530		res = nvme_identify(dev, i, 0, dma_addr);
1531		if (res)
1532			continue;
1533
1534		if (id_ns->ncap == 0)
1535			continue;
1536
1537		res = nvme_get_features(dev, NVME_FEAT_LBA_RANGE, i,
1538							dma_addr + 4096, NULL);
1539		if (res)
1540			continue;
1541
1542		ns = nvme_alloc_ns(dev, i, mem, mem + 4096);
1543		if (ns)
1544			list_add_tail(&ns->list, &dev->namespaces);
1545	}
1546	list_for_each_entry(ns, &dev->namespaces, list)
1547		add_disk(ns->disk);
1548
1549	goto out;
1550
1551 out_free:
1552	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
1553		list_del(&ns->list);
1554		nvme_ns_free(ns);
1555	}
1556
1557 out:
1558	dma_free_coherent(&dev->pci_dev->dev, 8192, mem, dma_addr);
1559	return res;
1560}
1561
1562static int nvme_dev_remove(struct nvme_dev *dev)
1563{
1564	struct nvme_ns *ns, *next;
1565
1566	spin_lock(&dev_list_lock);
1567	list_del(&dev->node);
1568	spin_unlock(&dev_list_lock);
1569
1570	list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
1571		list_del(&ns->list);
1572		del_gendisk(ns->disk);
1573		nvme_ns_free(ns);
1574	}
1575
1576	nvme_free_queues(dev);
1577
1578	return 0;
1579}
1580
1581static int nvme_setup_prp_pools(struct nvme_dev *dev)
1582{
1583	struct device *dmadev = &dev->pci_dev->dev;
1584	dev->prp_page_pool = dma_pool_create("prp list page", dmadev,
1585						PAGE_SIZE, PAGE_SIZE, 0);
1586	if (!dev->prp_page_pool)
1587		return -ENOMEM;
1588
1589	/* Optimisation for I/Os between 4k and 128k */
1590	dev->prp_small_pool = dma_pool_create("prp list 256", dmadev,
1591						256, 256, 0);
1592	if (!dev->prp_small_pool) {
1593		dma_pool_destroy(dev->prp_page_pool);
1594		return -ENOMEM;
1595	}
1596	return 0;
1597}
1598
1599static void nvme_release_prp_pools(struct nvme_dev *dev)
1600{
1601	dma_pool_destroy(dev->prp_page_pool);
1602	dma_pool_destroy(dev->prp_small_pool);
1603}
1604
1605static DEFINE_IDA(nvme_instance_ida);
1606
1607static int nvme_set_instance(struct nvme_dev *dev)
1608{
1609	int instance, error;
1610
1611	do {
1612		if (!ida_pre_get(&nvme_instance_ida, GFP_KERNEL))
1613			return -ENODEV;
1614
1615		spin_lock(&dev_list_lock);
1616		error = ida_get_new(&nvme_instance_ida, &instance);
1617		spin_unlock(&dev_list_lock);
1618	} while (error == -EAGAIN);
1619
1620	if (error)
1621		return -ENODEV;
1622
1623	dev->instance = instance;
1624	return 0;
1625}
1626
1627static void nvme_release_instance(struct nvme_dev *dev)
1628{
1629	spin_lock(&dev_list_lock);
1630	ida_remove(&nvme_instance_ida, dev->instance);
1631	spin_unlock(&dev_list_lock);
1632}
1633
1634static int __devinit nvme_probe(struct pci_dev *pdev,
1635						const struct pci_device_id *id)
1636{
1637	int bars, result = -ENOMEM;
1638	struct nvme_dev *dev;
1639
1640	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1641	if (!dev)
1642		return -ENOMEM;
1643	dev->entry = kcalloc(num_possible_cpus(), sizeof(*dev->entry),
1644								GFP_KERNEL);
1645	if (!dev->entry)
1646		goto free;
1647	dev->queues = kcalloc(num_possible_cpus() + 1, sizeof(void *),
1648								GFP_KERNEL);
1649	if (!dev->queues)
1650		goto free;
1651
1652	if (pci_enable_device_mem(pdev))
1653		goto free;
1654	pci_set_master(pdev);
1655	bars = pci_select_bars(pdev, IORESOURCE_MEM);
1656	if (pci_request_selected_regions(pdev, bars, "nvme"))
1657		goto disable;
1658
1659	INIT_LIST_HEAD(&dev->namespaces);
1660	dev->pci_dev = pdev;
1661	pci_set_drvdata(pdev, dev);
1662	dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
1663	dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
1664	result = nvme_set_instance(dev);
1665	if (result)
1666		goto disable;
1667
1668	dev->entry[0].vector = pdev->irq;
1669
1670	result = nvme_setup_prp_pools(dev);
1671	if (result)
1672		goto disable_msix;
1673
1674	dev->bar = ioremap(pci_resource_start(pdev, 0), 8192);
1675	if (!dev->bar) {
1676		result = -ENOMEM;
1677		goto disable_msix;
1678	}
1679
1680	result = nvme_configure_admin_queue(dev);
1681	if (result)
1682		goto unmap;
1683	dev->queue_count++;
1684
1685	spin_lock(&dev_list_lock);
1686	list_add(&dev->node, &dev_list);
1687	spin_unlock(&dev_list_lock);
1688
1689	result = nvme_dev_add(dev);
1690	if (result)
1691		goto delete;
1692
1693	return 0;
1694
1695 delete:
1696	spin_lock(&dev_list_lock);
1697	list_del(&dev->node);
1698	spin_unlock(&dev_list_lock);
1699
1700	nvme_free_queues(dev);
1701 unmap:
1702	iounmap(dev->bar);
1703 disable_msix:
1704	pci_disable_msix(pdev);
1705	nvme_release_instance(dev);
1706	nvme_release_prp_pools(dev);
1707 disable:
1708	pci_disable_device(pdev);
1709	pci_release_regions(pdev);
1710 free:
1711	kfree(dev->queues);
1712	kfree(dev->entry);
1713	kfree(dev);
1714	return result;
1715}
1716
1717static void __devexit nvme_remove(struct pci_dev *pdev)
1718{
1719	struct nvme_dev *dev = pci_get_drvdata(pdev);
1720	nvme_dev_remove(dev);
1721	pci_disable_msix(pdev);
1722	iounmap(dev->bar);
1723	nvme_release_instance(dev);
1724	nvme_release_prp_pools(dev);
1725	pci_disable_device(pdev);
1726	pci_release_regions(pdev);
1727	kfree(dev->queues);
1728	kfree(dev->entry);
1729	kfree(dev);
1730}
1731
1732/* These functions are yet to be implemented */
1733#define nvme_error_detected NULL
1734#define nvme_dump_registers NULL
1735#define nvme_link_reset NULL
1736#define nvme_slot_reset NULL
1737#define nvme_error_resume NULL
1738#define nvme_suspend NULL
1739#define nvme_resume NULL
1740
1741static const struct pci_error_handlers nvme_err_handler = {
1742	.error_detected	= nvme_error_detected,
1743	.mmio_enabled	= nvme_dump_registers,
1744	.link_reset	= nvme_link_reset,
1745	.slot_reset	= nvme_slot_reset,
1746	.resume		= nvme_error_resume,
1747};
1748
1749/* Move to pci_ids.h later */
1750#define PCI_CLASS_STORAGE_EXPRESS	0x010802
1751
1752static DEFINE_PCI_DEVICE_TABLE(nvme_id_table) = {
1753	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
1754	{ 0, }
1755};
1756MODULE_DEVICE_TABLE(pci, nvme_id_table);
1757
1758static struct pci_driver nvme_driver = {
1759	.name		= "nvme",
1760	.id_table	= nvme_id_table,
1761	.probe		= nvme_probe,
1762	.remove		= __devexit_p(nvme_remove),
1763	.suspend	= nvme_suspend,
1764	.resume		= nvme_resume,
1765	.err_handler	= &nvme_err_handler,
1766};
1767
1768static int __init nvme_init(void)
1769{
1770	int result;
1771
1772	nvme_thread = kthread_run(nvme_kthread, NULL, "nvme");
1773	if (IS_ERR(nvme_thread))
1774		return PTR_ERR(nvme_thread);
1775
1776	result = register_blkdev(nvme_major, "nvme");
1777	if (result < 0)
1778		goto kill_kthread;
1779	else if (result > 0)
1780		nvme_major = result;
1781
1782	result = pci_register_driver(&nvme_driver);
1783	if (result)
1784		goto unregister_blkdev;
1785	return 0;
1786
1787 unregister_blkdev:
1788	unregister_blkdev(nvme_major, "nvme");
1789 kill_kthread:
1790	kthread_stop(nvme_thread);
1791	return result;
1792}
1793
1794static void __exit nvme_exit(void)
1795{
1796	pci_unregister_driver(&nvme_driver);
1797	unregister_blkdev(nvme_major, "nvme");
1798	kthread_stop(nvme_thread);
1799}
1800
1801MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
1802MODULE_LICENSE("GPL");
1803MODULE_VERSION("0.8");
1804module_init(nvme_init);
1805module_exit(nvme_exit);
1806