9377cf32f8131e1a1a1fa2030efb95959ecfe463
[linux-2.6.git] / drivers / block / nvme.c
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/blkdev.h>
22 #include <linux/errno.h>
23 #include <linux/fs.h>
24 #include <linux/genhd.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/io.h>
28 #include <linux/kdev_t.h>
29 #include <linux/kernel.h>
30 #include <linux/mm.h>
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/pci.h>
34 #include <linux/sched.h>
35 #include <linux/slab.h>
36 #include <linux/types.h>
37 #include <linux/version.h>
38
39 #define NVME_Q_DEPTH 1024
40 #define SQ_SIZE(depth)          (depth * sizeof(struct nvme_command))
41 #define CQ_SIZE(depth)          (depth * sizeof(struct nvme_completion))
42 #define NVME_MINORS 64
43
44 static int nvme_major;
45 module_param(nvme_major, int, 0);
46
47 /*
48  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
49  */
50 struct nvme_dev {
51         struct nvme_queue **queues;
52         u32 __iomem *dbs;
53         struct pci_dev *pci_dev;
54         int instance;
55         int queue_count;
56         u32 ctrl_config;
57         struct msix_entry *entry;
58         struct nvme_bar __iomem *bar;
59         struct list_head namespaces;
60         char serial[20];
61         char model[40];
62         char firmware_rev[8];
63 };
64
65 /*
66  * An NVM Express namespace is equivalent to a SCSI LUN
67  */
68 struct nvme_ns {
69         struct list_head list;
70
71         struct nvme_dev *dev;
72         struct request_queue *queue;
73         struct gendisk *disk;
74
75         int ns_id;
76         int lba_shift;
77 };
78
79 /*
80  * An NVM Express queue.  Each device has at least two (one for admin
81  * commands and one for I/O commands).
82  */
83 struct nvme_queue {
84         struct device *q_dmadev;
85         spinlock_t q_lock;
86         struct nvme_command *sq_cmds;
87         volatile struct nvme_completion *cqes;
88         dma_addr_t sq_dma_addr;
89         dma_addr_t cq_dma_addr;
90         wait_queue_head_t sq_full;
91         struct bio_list sq_cong;
92         u32 __iomem *q_db;
93         u16 q_depth;
94         u16 cq_vector;
95         u16 sq_head;
96         u16 sq_tail;
97         u16 cq_head;
98         u16 cq_phase;
99         unsigned long cmdid_data[];
100 };
101
102 /*
103  * Check we didin't inadvertently grow the command struct
104  */
105 static inline void _nvme_check_size(void)
106 {
107         BUILD_BUG_ON(sizeof(struct nvme_rw_command) != 64);
108         BUILD_BUG_ON(sizeof(struct nvme_create_cq) != 64);
109         BUILD_BUG_ON(sizeof(struct nvme_create_sq) != 64);
110         BUILD_BUG_ON(sizeof(struct nvme_delete_queue) != 64);
111         BUILD_BUG_ON(sizeof(struct nvme_features) != 64);
112         BUILD_BUG_ON(sizeof(struct nvme_command) != 64);
113         BUILD_BUG_ON(sizeof(struct nvme_id_ctrl) != 4096);
114         BUILD_BUG_ON(sizeof(struct nvme_id_ns) != 4096);
115         BUILD_BUG_ON(sizeof(struct nvme_lba_range_type) != 64);
116 }
117
118 /**
119  * alloc_cmdid - Allocate a Command ID
120  * @param nvmeq The queue that will be used for this command
121  * @param ctx A pointer that will be passed to the handler
122  * @param handler The ID of the handler to call
123  *
124  * Allocate a Command ID for a queue.  The data passed in will
125  * be passed to the completion handler.  This is implemented by using
126  * the bottom two bits of the ctx pointer to store the handler ID.
127  * Passing in a pointer that's not 4-byte aligned will cause a BUG.
128  * We can change this if it becomes a problem.
129  */
130 static int alloc_cmdid(struct nvme_queue *nvmeq, void *ctx, int handler)
131 {
132         int depth = nvmeq->q_depth;
133         unsigned long data = (unsigned long)ctx | handler;
134         int cmdid;
135
136         BUG_ON((unsigned long)ctx & 3);
137
138         do {
139                 cmdid = find_first_zero_bit(nvmeq->cmdid_data, depth);
140                 if (cmdid >= depth)
141                         return -EBUSY;
142         } while (test_and_set_bit(cmdid, nvmeq->cmdid_data));
143
144         nvmeq->cmdid_data[cmdid + BITS_TO_LONGS(depth)] = data;
145         return cmdid;
146 }
147
148 static int alloc_cmdid_killable(struct nvme_queue *nvmeq, void *ctx,
149                                                                 int handler)
150 {
151         int cmdid;
152         wait_event_killable(nvmeq->sq_full,
153                         (cmdid = alloc_cmdid(nvmeq, ctx, handler)) >= 0);
154         return (cmdid < 0) ? -EINTR : cmdid;
155 }
156
157 /* If you need more than four handlers, you'll need to change how
158  * alloc_cmdid and nvme_process_cq work
159  */
160 enum {
161         sync_completion_id = 0,
162         bio_completion_id,
163 };
164
165 static unsigned long free_cmdid(struct nvme_queue *nvmeq, int cmdid)
166 {
167         unsigned long data;
168
169         data = nvmeq->cmdid_data[cmdid + BITS_TO_LONGS(nvmeq->q_depth)];
170         clear_bit(cmdid, nvmeq->cmdid_data);
171         wake_up(&nvmeq->sq_full);
172         return data;
173 }
174
175 static struct nvme_queue *get_nvmeq(struct nvme_ns *ns)
176 {
177         int qid, cpu = get_cpu();
178         if (cpu < ns->dev->queue_count)
179                 qid = cpu + 1;
180         else
181                 qid = (cpu % rounddown_pow_of_two(ns->dev->queue_count)) + 1;
182         return ns->dev->queues[qid];
183 }
184
185 static void put_nvmeq(struct nvme_queue *nvmeq)
186 {
187         put_cpu();
188 }
189
190 /**
191  * nvme_submit_cmd: Copy a command into a queue and ring the doorbell
192  * @nvmeq: The queue to use
193  * @cmd: The command to send
194  *
195  * Safe to use from interrupt context
196  */
197 static int nvme_submit_cmd(struct nvme_queue *nvmeq, struct nvme_command *cmd)
198 {
199         unsigned long flags;
200         u16 tail;
201         /* XXX: Need to check tail isn't going to overrun head */
202         spin_lock_irqsave(&nvmeq->q_lock, flags);
203         tail = nvmeq->sq_tail;
204         memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
205         writel(tail, nvmeq->q_db);
206         if (++tail == nvmeq->q_depth)
207                 tail = 0;
208         nvmeq->sq_tail = tail;
209         spin_unlock_irqrestore(&nvmeq->q_lock, flags);
210
211         return 0;
212 }
213
214 struct nvme_req_info {
215         struct bio *bio;
216         int nents;
217         struct scatterlist sg[0];
218 };
219
220 /* XXX: use a mempool */
221 static struct nvme_req_info *alloc_info(unsigned nseg, gfp_t gfp)
222 {
223         return kmalloc(sizeof(struct nvme_req_info) +
224                         sizeof(struct scatterlist) * nseg, gfp);
225 }
226
227 static void free_info(struct nvme_req_info *info)
228 {
229         kfree(info);
230 }
231
232 static void bio_completion(struct nvme_queue *nvmeq, void *ctx,
233                                                 struct nvme_completion *cqe)
234 {
235         struct nvme_req_info *info = ctx;
236         struct bio *bio = info->bio;
237         u16 status = le16_to_cpup(&cqe->status) >> 1;
238
239         dma_unmap_sg(nvmeq->q_dmadev, info->sg, info->nents,
240                         bio_data_dir(bio) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
241         free_info(info);
242         bio_endio(bio, status ? -EIO : 0);
243 }
244
245 /* length is in bytes */
246 static void nvme_setup_prps(struct nvme_common_command *cmd,
247                                         struct scatterlist *sg, int length)
248 {
249         int dma_len = sg_dma_len(sg);
250         u64 dma_addr = sg_dma_address(sg);
251         int offset = offset_in_page(dma_addr);
252
253         cmd->prp1 = cpu_to_le64(dma_addr);
254         length -= (PAGE_SIZE - offset);
255         if (length <= 0)
256                 return;
257
258         dma_len -= (PAGE_SIZE - offset);
259         if (dma_len) {
260                 dma_addr += (PAGE_SIZE - offset);
261         } else {
262                 sg = sg_next(sg);
263                 dma_addr = sg_dma_address(sg);
264                 dma_len = sg_dma_len(sg);
265         }
266
267         if (length <= PAGE_SIZE) {
268                 cmd->prp2 = cpu_to_le64(dma_addr);
269                 return;
270         }
271
272         /* XXX: support PRP lists */
273 }
274
275 static int nvme_map_bio(struct device *dev, struct nvme_req_info *info,
276                 struct bio *bio, enum dma_data_direction dma_dir, int psegs)
277 {
278         struct bio_vec *bvec;
279         struct scatterlist *sg = info->sg;
280         int i, nsegs;
281
282         sg_init_table(sg, psegs);
283         bio_for_each_segment(bvec, bio, i) {
284                 sg_set_page(sg, bvec->bv_page, bvec->bv_len, bvec->bv_offset);
285                 /* XXX: handle non-mergable here */
286                 nsegs++;
287         }
288         info->nents = nsegs;
289
290         return dma_map_sg(dev, info->sg, info->nents, dma_dir);
291 }
292
293 static int nvme_submit_bio_queue(struct nvme_queue *nvmeq, struct nvme_ns *ns,
294                                                                 struct bio *bio)
295 {
296         struct nvme_command *cmnd;
297         struct nvme_req_info *info;
298         enum dma_data_direction dma_dir;
299         int cmdid;
300         u16 control;
301         u32 dsmgmt;
302         unsigned long flags;
303         int psegs = bio_phys_segments(ns->queue, bio);
304
305         info = alloc_info(psegs, GFP_NOIO);
306         if (!info)
307                 goto congestion;
308         info->bio = bio;
309
310         cmdid = alloc_cmdid(nvmeq, info, bio_completion_id);
311         if (unlikely(cmdid < 0))
312                 goto free_info;
313
314         control = 0;
315         if (bio->bi_rw & REQ_FUA)
316                 control |= NVME_RW_FUA;
317         if (bio->bi_rw & (REQ_FAILFAST_DEV | REQ_RAHEAD))
318                 control |= NVME_RW_LR;
319
320         dsmgmt = 0;
321         if (bio->bi_rw & REQ_RAHEAD)
322                 dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH;
323
324         spin_lock_irqsave(&nvmeq->q_lock, flags);
325         cmnd = &nvmeq->sq_cmds[nvmeq->sq_tail];
326
327         memset(cmnd, 0, sizeof(*cmnd));
328         if (bio_data_dir(bio)) {
329                 cmnd->rw.opcode = nvme_cmd_write;
330                 dma_dir = DMA_TO_DEVICE;
331         } else {
332                 cmnd->rw.opcode = nvme_cmd_read;
333                 dma_dir = DMA_FROM_DEVICE;
334         }
335
336         nvme_map_bio(nvmeq->q_dmadev, info, bio, dma_dir, psegs);
337
338         cmnd->rw.flags = 1;
339         cmnd->rw.command_id = cmdid;
340         cmnd->rw.nsid = cpu_to_le32(ns->ns_id);
341         nvme_setup_prps(&cmnd->common, info->sg, bio->bi_size);
342         cmnd->rw.slba = cpu_to_le64(bio->bi_sector >> (ns->lba_shift - 9));
343         cmnd->rw.length = cpu_to_le16((bio->bi_size >> ns->lba_shift) - 1);
344         cmnd->rw.control = cpu_to_le16(control);
345         cmnd->rw.dsmgmt = cpu_to_le32(dsmgmt);
346
347         writel(nvmeq->sq_tail, nvmeq->q_db);
348         if (++nvmeq->sq_tail == nvmeq->q_depth)
349                 nvmeq->sq_tail = 0;
350
351         spin_unlock_irqrestore(&nvmeq->q_lock, flags);
352
353         return 0;
354
355  free_info:
356         free_info(info);
357  congestion:
358         return -EBUSY;
359 }
360
361 /*
362  * NB: return value of non-zero would mean that we were a stacking driver.
363  * make_request must always succeed.
364  */
365 static int nvme_make_request(struct request_queue *q, struct bio *bio)
366 {
367         struct nvme_ns *ns = q->queuedata;
368         struct nvme_queue *nvmeq = get_nvmeq(ns);
369
370         if (nvme_submit_bio_queue(nvmeq, ns, bio)) {
371                 blk_set_queue_congested(q, rw_is_sync(bio->bi_rw));
372                 bio_list_add(&nvmeq->sq_cong, bio);
373         }
374         put_nvmeq(nvmeq);
375
376         return 0;
377 }
378
379 struct sync_cmd_info {
380         struct task_struct *task;
381         u32 result;
382         int status;
383 };
384
385 static void sync_completion(struct nvme_queue *nvmeq, void *ctx,
386                                                 struct nvme_completion *cqe)
387 {
388         struct sync_cmd_info *cmdinfo = ctx;
389         cmdinfo->result = le32_to_cpup(&cqe->result);
390         cmdinfo->status = le16_to_cpup(&cqe->status) >> 1;
391         wake_up_process(cmdinfo->task);
392 }
393
394 typedef void (*completion_fn)(struct nvme_queue *, void *,
395                                                 struct nvme_completion *);
396
397 static irqreturn_t nvme_process_cq(struct nvme_queue *nvmeq)
398 {
399         u16 head, phase;
400
401         static const completion_fn completions[4] = {
402                 [sync_completion_id] = sync_completion,
403                 [bio_completion_id]  = bio_completion,
404         };
405
406         head = nvmeq->cq_head;
407         phase = nvmeq->cq_phase;
408
409         for (;;) {
410                 unsigned long data;
411                 void *ptr;
412                 unsigned char handler;
413                 struct nvme_completion cqe = nvmeq->cqes[head];
414                 if ((le16_to_cpu(cqe.status) & 1) != phase)
415                         break;
416                 nvmeq->sq_head = le16_to_cpu(cqe.sq_head);
417                 if (++head == nvmeq->q_depth) {
418                         head = 0;
419                         phase = !phase;
420                 }
421
422                 data = free_cmdid(nvmeq, cqe.command_id);
423                 handler = data & 3;
424                 ptr = (void *)(data & ~3UL);
425                 completions[handler](nvmeq, ptr, &cqe);
426         }
427
428         /* If the controller ignores the cq head doorbell and continuously
429          * writes to the queue, it is theoretically possible to wrap around
430          * the queue twice and mistakenly return IRQ_NONE.  Linux only
431          * requires that 0.1% of your interrupts are handled, so this isn't
432          * a big problem.
433          */
434         if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
435                 return IRQ_NONE;
436
437         writel(head, nvmeq->q_db + 1);
438         nvmeq->cq_head = head;
439         nvmeq->cq_phase = phase;
440
441         return IRQ_HANDLED;
442 }
443
444 static irqreturn_t nvme_irq(int irq, void *data)
445 {
446         return nvme_process_cq(data);
447 }
448
449 /*
450  * Returns 0 on success.  If the result is negative, it's a Linux error code;
451  * if the result is positive, it's an NVM Express status code
452  */
453 static int nvme_submit_sync_cmd(struct nvme_queue *q, struct nvme_command *cmd,
454                                                                 u32 *result)
455 {
456         int cmdid;
457         struct sync_cmd_info cmdinfo;
458
459         cmdinfo.task = current;
460         cmdinfo.status = -EINTR;
461
462         cmdid = alloc_cmdid_killable(q, &cmdinfo, sync_completion_id);
463         if (cmdid < 0)
464                 return cmdid;
465         cmd->common.command_id = cmdid;
466
467         set_current_state(TASK_UNINTERRUPTIBLE);
468         nvme_submit_cmd(q, cmd);
469         schedule();
470
471         if (result)
472                 *result = cmdinfo.result;
473
474         return cmdinfo.status;
475 }
476
477 static int nvme_submit_admin_cmd(struct nvme_dev *dev, struct nvme_command *cmd,
478                                                                 u32 *result)
479 {
480         return nvme_submit_sync_cmd(dev->queues[0], cmd, result);
481 }
482
483 static int adapter_delete_queue(struct nvme_dev *dev, u8 opcode, u16 id)
484 {
485         int status;
486         struct nvme_command c;
487
488         memset(&c, 0, sizeof(c));
489         c.delete_queue.opcode = opcode;
490         c.delete_queue.qid = cpu_to_le16(id);
491
492         status = nvme_submit_admin_cmd(dev, &c, NULL);
493         if (status)
494                 return -EIO;
495         return 0;
496 }
497
498 static int adapter_alloc_cq(struct nvme_dev *dev, u16 qid,
499                                                 struct nvme_queue *nvmeq)
500 {
501         int status;
502         struct nvme_command c;
503         int flags = NVME_QUEUE_PHYS_CONTIG | NVME_CQ_IRQ_ENABLED;
504
505         memset(&c, 0, sizeof(c));
506         c.create_cq.opcode = nvme_admin_create_cq;
507         c.create_cq.prp1 = cpu_to_le64(nvmeq->cq_dma_addr);
508         c.create_cq.cqid = cpu_to_le16(qid);
509         c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
510         c.create_cq.cq_flags = cpu_to_le16(flags);
511         c.create_cq.irq_vector = cpu_to_le16(nvmeq->cq_vector);
512
513         status = nvme_submit_admin_cmd(dev, &c, NULL);
514         if (status)
515                 return -EIO;
516         return 0;
517 }
518
519 static int adapter_alloc_sq(struct nvme_dev *dev, u16 qid,
520                                                 struct nvme_queue *nvmeq)
521 {
522         int status;
523         struct nvme_command c;
524         int flags = NVME_QUEUE_PHYS_CONTIG | NVME_SQ_PRIO_MEDIUM;
525
526         memset(&c, 0, sizeof(c));
527         c.create_sq.opcode = nvme_admin_create_sq;
528         c.create_sq.prp1 = cpu_to_le64(nvmeq->sq_dma_addr);
529         c.create_sq.sqid = cpu_to_le16(qid);
530         c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1);
531         c.create_sq.sq_flags = cpu_to_le16(flags);
532         c.create_sq.cqid = cpu_to_le16(qid);
533
534         status = nvme_submit_admin_cmd(dev, &c, NULL);
535         if (status)
536                 return -EIO;
537         return 0;
538 }
539
540 static int adapter_delete_cq(struct nvme_dev *dev, u16 cqid)
541 {
542         return adapter_delete_queue(dev, nvme_admin_delete_cq, cqid);
543 }
544
545 static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
546 {
547         return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
548 }
549
550 static void nvme_free_queue(struct nvme_dev *dev, int qid)
551 {
552         struct nvme_queue *nvmeq = dev->queues[qid];
553
554         free_irq(dev->entry[nvmeq->cq_vector].vector, nvmeq);
555
556         /* Don't tell the adapter to delete the admin queue */
557         if (qid) {
558                 adapter_delete_sq(dev, qid);
559                 adapter_delete_cq(dev, qid);
560         }
561
562         dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
563                                 (void *)nvmeq->cqes, nvmeq->cq_dma_addr);
564         dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
565                                         nvmeq->sq_cmds, nvmeq->sq_dma_addr);
566         kfree(nvmeq);
567 }
568
569 static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
570                                                         int depth, int vector)
571 {
572         struct device *dmadev = &dev->pci_dev->dev;
573         unsigned extra = (depth + BITS_TO_LONGS(depth)) * sizeof(long);
574         struct nvme_queue *nvmeq = kzalloc(sizeof(*nvmeq) + extra, GFP_KERNEL);
575         if (!nvmeq)
576                 return NULL;
577
578         nvmeq->cqes = dma_alloc_coherent(dmadev, CQ_SIZE(depth),
579                                         &nvmeq->cq_dma_addr, GFP_KERNEL);
580         if (!nvmeq->cqes)
581                 goto free_nvmeq;
582         memset((void *)nvmeq->cqes, 0, CQ_SIZE(depth));
583
584         nvmeq->sq_cmds = dma_alloc_coherent(dmadev, SQ_SIZE(depth),
585                                         &nvmeq->sq_dma_addr, GFP_KERNEL);
586         if (!nvmeq->sq_cmds)
587                 goto free_cqdma;
588
589         nvmeq->q_dmadev = dmadev;
590         spin_lock_init(&nvmeq->q_lock);
591         nvmeq->cq_head = 0;
592         nvmeq->cq_phase = 1;
593         init_waitqueue_head(&nvmeq->sq_full);
594         bio_list_init(&nvmeq->sq_cong);
595         nvmeq->q_db = &dev->dbs[qid * 2];
596         nvmeq->q_depth = depth;
597         nvmeq->cq_vector = vector;
598
599         return nvmeq;
600
601  free_cqdma:
602         dma_free_coherent(dmadev, CQ_SIZE(nvmeq->q_depth), (void *)nvmeq->cqes,
603                                                         nvmeq->cq_dma_addr);
604  free_nvmeq:
605         kfree(nvmeq);
606         return NULL;
607 }
608
609 static int queue_request_irq(struct nvme_dev *dev, struct nvme_queue *nvmeq,
610                                                         const char *name)
611 {
612         return request_irq(dev->entry[nvmeq->cq_vector].vector, nvme_irq,
613                                 IRQF_DISABLED | IRQF_SHARED, name, nvmeq);
614 }
615
616 static __devinit struct nvme_queue *nvme_create_queue(struct nvme_dev *dev,
617                                         int qid, int cq_size, int vector)
618 {
619         int result;
620         struct nvme_queue *nvmeq = nvme_alloc_queue(dev, qid, cq_size, vector);
621
622         result = adapter_alloc_cq(dev, qid, nvmeq);
623         if (result < 0)
624                 goto free_nvmeq;
625
626         result = adapter_alloc_sq(dev, qid, nvmeq);
627         if (result < 0)
628                 goto release_cq;
629
630         result = queue_request_irq(dev, nvmeq, "nvme");
631         if (result < 0)
632                 goto release_sq;
633
634         return nvmeq;
635
636  release_sq:
637         adapter_delete_sq(dev, qid);
638  release_cq:
639         adapter_delete_cq(dev, qid);
640  free_nvmeq:
641         dma_free_coherent(nvmeq->q_dmadev, CQ_SIZE(nvmeq->q_depth),
642                                 (void *)nvmeq->cqes, nvmeq->cq_dma_addr);
643         dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
644                                         nvmeq->sq_cmds, nvmeq->sq_dma_addr);
645         kfree(nvmeq);
646         return NULL;
647 }
648
649 static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
650 {
651         int result;
652         u32 aqa;
653         struct nvme_queue *nvmeq;
654
655         dev->dbs = ((void __iomem *)dev->bar) + 4096;
656
657         nvmeq = nvme_alloc_queue(dev, 0, 64, 0);
658
659         aqa = nvmeq->q_depth - 1;
660         aqa |= aqa << 16;
661
662         dev->ctrl_config = NVME_CC_ENABLE | NVME_CC_CSS_NVM;
663         dev->ctrl_config |= (PAGE_SHIFT - 12) << NVME_CC_MPS_SHIFT;
664         dev->ctrl_config |= NVME_CC_ARB_RR | NVME_CC_SHN_NONE;
665
666         writel(aqa, &dev->bar->aqa);
667         writeq(nvmeq->sq_dma_addr, &dev->bar->asq);
668         writeq(nvmeq->cq_dma_addr, &dev->bar->acq);
669         writel(dev->ctrl_config, &dev->bar->cc);
670
671         while (!(readl(&dev->bar->csts) & NVME_CSTS_RDY)) {
672                 msleep(100);
673                 if (fatal_signal_pending(current))
674                         return -EINTR;
675         }
676
677         result = queue_request_irq(dev, nvmeq, "nvme admin");
678         dev->queues[0] = nvmeq;
679         return result;
680 }
681
682 static int nvme_map_user_pages(struct nvme_dev *dev, int write,
683                                 unsigned long addr, unsigned length,
684                                 struct scatterlist **sgp)
685 {
686         int i, err, count, nents, offset;
687         struct scatterlist *sg;
688         struct page **pages;
689
690         if (addr & 3)
691                 return -EINVAL;
692         if (!length)
693                 return -EINVAL;
694
695         offset = offset_in_page(addr);
696         count = DIV_ROUND_UP(offset + length, PAGE_SIZE);
697         pages = kcalloc(count, sizeof(*pages), GFP_KERNEL);
698
699         err = get_user_pages_fast(addr, count, 1, pages);
700         if (err < count) {
701                 count = err;
702                 err = -EFAULT;
703                 goto put_pages;
704         }
705
706         sg = kcalloc(count, sizeof(*sg), GFP_KERNEL);
707         sg_init_table(sg, count);
708         sg_set_page(&sg[0], pages[0], PAGE_SIZE - offset, offset);
709         length -= (PAGE_SIZE - offset);
710         for (i = 1; i < count; i++) {
711                 sg_set_page(&sg[i], pages[i], min_t(int, length, PAGE_SIZE), 0);
712                 length -= PAGE_SIZE;
713         }
714
715         err = -ENOMEM;
716         nents = dma_map_sg(&dev->pci_dev->dev, sg, count,
717                                 write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
718         if (!nents)
719                 goto put_pages;
720
721         kfree(pages);
722         *sgp = sg;
723         return nents;
724
725  put_pages:
726         for (i = 0; i < count; i++)
727                 put_page(pages[i]);
728         kfree(pages);
729         return err;
730 }
731
732 static void nvme_unmap_user_pages(struct nvme_dev *dev, int write,
733                                 unsigned long addr, int length,
734                                 struct scatterlist *sg, int nents)
735 {
736         int i, count;
737
738         count = DIV_ROUND_UP(offset_in_page(addr) + length, PAGE_SIZE);
739         dma_unmap_sg(&dev->pci_dev->dev, sg, nents, DMA_FROM_DEVICE);
740
741         for (i = 0; i < count; i++)
742                 put_page(sg_page(&sg[i]));
743 }
744
745 static int nvme_submit_user_admin_command(struct nvme_dev *dev,
746                                         unsigned long addr, unsigned length,
747                                         struct nvme_command *cmd)
748 {
749         int err, nents;
750         struct scatterlist *sg;
751
752         nents = nvme_map_user_pages(dev, 0, addr, length, &sg);
753         if (nents < 0)
754                 return nents;
755         nvme_setup_prps(&cmd->common, sg, length);
756         err = nvme_submit_admin_cmd(dev, cmd, NULL);
757         nvme_unmap_user_pages(dev, 0, addr, length, sg, nents);
758         return err ? -EIO : 0;
759 }
760
761 static int nvme_identify(struct nvme_ns *ns, unsigned long addr, int cns)
762 {
763         struct nvme_command c;
764
765         memset(&c, 0, sizeof(c));
766         c.identify.opcode = nvme_admin_identify;
767         c.identify.nsid = cns ? 0 : cpu_to_le32(ns->ns_id);
768         c.identify.cns = cpu_to_le32(cns);
769
770         return nvme_submit_user_admin_command(ns->dev, addr, 4096, &c);
771 }
772
773 static int nvme_get_range_type(struct nvme_ns *ns, unsigned long addr)
774 {
775         struct nvme_command c;
776
777         memset(&c, 0, sizeof(c));
778         c.features.opcode = nvme_admin_get_features;
779         c.features.nsid = cpu_to_le32(ns->ns_id);
780         c.features.fid = cpu_to_le32(NVME_FEAT_LBA_RANGE);
781
782         return nvme_submit_user_admin_command(ns->dev, addr, 4096, &c);
783 }
784
785 static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
786 {
787         struct nvme_dev *dev = ns->dev;
788         struct nvme_queue *nvmeq;
789         struct nvme_user_io io;
790         struct nvme_command c;
791         unsigned length;
792         u32 result;
793         int nents, status;
794         struct scatterlist *sg;
795
796         if (copy_from_user(&io, uio, sizeof(io)))
797                 return -EFAULT;
798         length = io.nblocks << io.block_shift;
799         nents = nvme_map_user_pages(dev, io.opcode & 1, io.addr, length, &sg);
800         if (nents < 0)
801                 return nents;
802
803         memset(&c, 0, sizeof(c));
804         c.rw.opcode = io.opcode;
805         c.rw.flags = io.flags;
806         c.rw.nsid = cpu_to_le32(io.nsid);
807         c.rw.slba = cpu_to_le64(io.slba);
808         c.rw.length = cpu_to_le16(io.nblocks - 1);
809         c.rw.control = cpu_to_le16(io.control);
810         c.rw.dsmgmt = cpu_to_le16(io.dsmgmt);
811         c.rw.reftag = cpu_to_le32(io.reftag);   /* XXX: endian? */
812         c.rw.apptag = cpu_to_le16(io.apptag);
813         c.rw.appmask = cpu_to_le16(io.appmask);
814         /* XXX: metadata */
815         nvme_setup_prps(&c.common, sg, length);
816
817         nvmeq = get_nvmeq(ns);
818         status = nvme_submit_sync_cmd(nvmeq, &c, &result);
819         put_nvmeq(nvmeq);
820
821         nvme_unmap_user_pages(dev, io.opcode & 1, io.addr, length, sg, nents);
822         put_user(result, &uio->result);
823         return status;
824 }
825
826 static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
827                                                         unsigned long arg)
828 {
829         struct nvme_ns *ns = bdev->bd_disk->private_data;
830
831         switch (cmd) {
832         case NVME_IOCTL_IDENTIFY_NS:
833                 return nvme_identify(ns, arg, 0);
834         case NVME_IOCTL_IDENTIFY_CTRL:
835                 return nvme_identify(ns, arg, 1);
836         case NVME_IOCTL_GET_RANGE_TYPE:
837                 return nvme_get_range_type(ns, arg);
838         case NVME_IOCTL_SUBMIT_IO:
839                 return nvme_submit_io(ns, (void __user *)arg);
840         default:
841                 return -ENOTTY;
842         }
843 }
844
845 static const struct block_device_operations nvme_fops = {
846         .owner          = THIS_MODULE,
847         .ioctl          = nvme_ioctl,
848 };
849
850 static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int index,
851                         struct nvme_id_ns *id, struct nvme_lba_range_type *rt)
852 {
853         struct nvme_ns *ns;
854         struct gendisk *disk;
855         int lbaf;
856
857         if (rt->attributes & NVME_LBART_ATTRIB_HIDE)
858                 return NULL;
859
860         ns = kzalloc(sizeof(*ns), GFP_KERNEL);
861         if (!ns)
862                 return NULL;
863         ns->queue = blk_alloc_queue(GFP_KERNEL);
864         if (!ns->queue)
865                 goto out_free_ns;
866         ns->queue->queue_flags = QUEUE_FLAG_DEFAULT | QUEUE_FLAG_NOMERGES |
867                                 QUEUE_FLAG_NONROT | QUEUE_FLAG_DISCARD;
868         blk_queue_make_request(ns->queue, nvme_make_request);
869         ns->dev = dev;
870         ns->queue->queuedata = ns;
871
872         disk = alloc_disk(NVME_MINORS);
873         if (!disk)
874                 goto out_free_queue;
875         ns->ns_id = index;
876         ns->disk = disk;
877         lbaf = id->flbas & 0xf;
878         ns->lba_shift = id->lbaf[lbaf].ds;
879
880         disk->major = nvme_major;
881         disk->minors = NVME_MINORS;
882         disk->first_minor = NVME_MINORS * index;
883         disk->fops = &nvme_fops;
884         disk->private_data = ns;
885         disk->queue = ns->queue;
886         sprintf(disk->disk_name, "nvme%dn%d", dev->instance, index);
887         set_capacity(disk, le64_to_cpup(&id->nsze) << (ns->lba_shift - 9));
888
889         return ns;
890
891  out_free_queue:
892         blk_cleanup_queue(ns->queue);
893  out_free_ns:
894         kfree(ns);
895         return NULL;
896 }
897
898 static void nvme_ns_free(struct nvme_ns *ns)
899 {
900         put_disk(ns->disk);
901         blk_cleanup_queue(ns->queue);
902         kfree(ns);
903 }
904
905 static int set_queue_count(struct nvme_dev *dev, int count)
906 {
907         int status;
908         u32 result;
909         struct nvme_command c;
910         u32 q_count = (count - 1) | ((count - 1) << 16);
911
912         memset(&c, 0, sizeof(c));
913         c.features.opcode = nvme_admin_get_features;
914         c.features.fid = cpu_to_le32(NVME_FEAT_NUM_QUEUES);
915         c.features.dword11 = cpu_to_le32(q_count);
916
917         status = nvme_submit_admin_cmd(dev, &c, &result);
918         if (status)
919                 return -EIO;
920         return min(result & 0xffff, result >> 16) + 1;
921 }
922
923 static int __devinit nvme_setup_io_queues(struct nvme_dev *dev)
924 {
925         int result, cpu, i, nr_queues;
926
927         nr_queues = num_online_cpus();
928         result = set_queue_count(dev, nr_queues);
929         if (result < 0)
930                 return result;
931         if (result < nr_queues)
932                 nr_queues = result;
933
934         /* Deregister the admin queue's interrupt */
935         free_irq(dev->entry[0].vector, dev->queues[0]);
936
937         for (i = 0; i < nr_queues; i++)
938                 dev->entry[i].entry = i;
939         for (;;) {
940                 result = pci_enable_msix(dev->pci_dev, dev->entry, nr_queues);
941                 if (result == 0) {
942                         break;
943                 } else if (result > 0) {
944                         nr_queues = result;
945                         continue;
946                 } else {
947                         nr_queues = 1;
948                         break;
949                 }
950         }
951
952         result = queue_request_irq(dev, dev->queues[0], "nvme admin");
953         /* XXX: handle failure here */
954
955         cpu = cpumask_first(cpu_online_mask);
956         for (i = 0; i < nr_queues; i++) {
957                 irq_set_affinity_hint(dev->entry[i].vector, get_cpu_mask(cpu));
958                 cpu = cpumask_next(cpu, cpu_online_mask);
959         }
960
961         for (i = 0; i < nr_queues; i++) {
962                 dev->queues[i + 1] = nvme_create_queue(dev, i + 1,
963                                                         NVME_Q_DEPTH, i);
964                 if (!dev->queues[i + 1])
965                         return -ENOMEM;
966                 dev->queue_count++;
967         }
968
969         return 0;
970 }
971
972 static void nvme_free_queues(struct nvme_dev *dev)
973 {
974         int i;
975
976         for (i = dev->queue_count - 1; i >= 0; i--)
977                 nvme_free_queue(dev, i);
978 }
979
980 static int __devinit nvme_dev_add(struct nvme_dev *dev)
981 {
982         int res, nn, i;
983         struct nvme_ns *ns, *next;
984         struct nvme_id_ctrl *ctrl;
985         void *id;
986         dma_addr_t dma_addr;
987         struct nvme_command cid, crt;
988
989         res = nvme_setup_io_queues(dev);
990         if (res)
991                 return res;
992
993         /* XXX: Switch to a SG list once prp2 works */
994         id = dma_alloc_coherent(&dev->pci_dev->dev, 8192, &dma_addr,
995                                                                 GFP_KERNEL);
996
997         memset(&cid, 0, sizeof(cid));
998         cid.identify.opcode = nvme_admin_identify;
999         cid.identify.nsid = 0;
1000         cid.identify.prp1 = cpu_to_le64(dma_addr);
1001         cid.identify.cns = cpu_to_le32(1);
1002
1003         res = nvme_submit_admin_cmd(dev, &cid, NULL);
1004         if (res) {
1005                 res = -EIO;
1006                 goto out_free;
1007         }
1008
1009         ctrl = id;
1010         nn = le32_to_cpup(&ctrl->nn);
1011         memcpy(dev->serial, ctrl->sn, sizeof(ctrl->sn));
1012         memcpy(dev->model, ctrl->mn, sizeof(ctrl->mn));
1013         memcpy(dev->firmware_rev, ctrl->fr, sizeof(ctrl->fr));
1014
1015         cid.identify.cns = 0;
1016         memset(&crt, 0, sizeof(crt));
1017         crt.features.opcode = nvme_admin_get_features;
1018         crt.features.prp1 = cpu_to_le64(dma_addr + 4096);
1019         crt.features.fid = cpu_to_le32(NVME_FEAT_LBA_RANGE);
1020
1021         for (i = 0; i < nn; i++) {
1022                 cid.identify.nsid = cpu_to_le32(i);
1023                 res = nvme_submit_admin_cmd(dev, &cid, NULL);
1024                 if (res)
1025                         continue;
1026
1027                 if (((struct nvme_id_ns *)id)->ncap == 0)
1028                         continue;
1029
1030                 crt.features.nsid = cpu_to_le32(i);
1031                 res = nvme_submit_admin_cmd(dev, &crt, NULL);
1032                 if (res)
1033                         continue;
1034
1035                 ns = nvme_alloc_ns(dev, i, id, id + 4096);
1036                 if (ns)
1037                         list_add_tail(&ns->list, &dev->namespaces);
1038         }
1039         list_for_each_entry(ns, &dev->namespaces, list)
1040                 add_disk(ns->disk);
1041
1042         dma_free_coherent(&dev->pci_dev->dev, 4096, id, dma_addr);
1043         return 0;
1044
1045  out_free:
1046         list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
1047                 list_del(&ns->list);
1048                 nvme_ns_free(ns);
1049         }
1050
1051         dma_free_coherent(&dev->pci_dev->dev, 4096, id, dma_addr);
1052         return res;
1053 }
1054
1055 static int nvme_dev_remove(struct nvme_dev *dev)
1056 {
1057         struct nvme_ns *ns, *next;
1058
1059         /* TODO: wait all I/O finished or cancel them */
1060
1061         list_for_each_entry_safe(ns, next, &dev->namespaces, list) {
1062                 list_del(&ns->list);
1063                 del_gendisk(ns->disk);
1064                 nvme_ns_free(ns);
1065         }
1066
1067         nvme_free_queues(dev);
1068
1069         return 0;
1070 }
1071
1072 /* XXX: Use an ida or something to let remove / add work correctly */
1073 static void nvme_set_instance(struct nvme_dev *dev)
1074 {
1075         static int instance;
1076         dev->instance = instance++;
1077 }
1078
1079 static void nvme_release_instance(struct nvme_dev *dev)
1080 {
1081 }
1082
1083 static int __devinit nvme_probe(struct pci_dev *pdev,
1084                                                 const struct pci_device_id *id)
1085 {
1086         int result = -ENOMEM;
1087         struct nvme_dev *dev;
1088
1089         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1090         if (!dev)
1091                 return -ENOMEM;
1092         dev->entry = kcalloc(num_possible_cpus(), sizeof(*dev->entry),
1093                                                                 GFP_KERNEL);
1094         if (!dev->entry)
1095                 goto free;
1096         dev->queues = kcalloc(num_possible_cpus() + 1, sizeof(void *),
1097                                                                 GFP_KERNEL);
1098         if (!dev->queues)
1099                 goto free;
1100
1101         INIT_LIST_HEAD(&dev->namespaces);
1102         dev->pci_dev = pdev;
1103         pci_set_drvdata(pdev, dev);
1104         dma_set_mask(&dev->pci_dev->dev, DMA_BIT_MASK(64));
1105         nvme_set_instance(dev);
1106         dev->entry[0].vector = pdev->irq;
1107
1108         dev->bar = ioremap(pci_resource_start(pdev, 0), 8192);
1109         if (!dev->bar) {
1110                 result = -ENOMEM;
1111                 goto disable;
1112         }
1113
1114         result = nvme_configure_admin_queue(dev);
1115         if (result)
1116                 goto unmap;
1117         dev->queue_count++;
1118
1119         result = nvme_dev_add(dev);
1120         if (result)
1121                 goto delete;
1122         return 0;
1123
1124  delete:
1125         nvme_free_queues(dev);
1126  unmap:
1127         iounmap(dev->bar);
1128  disable:
1129         pci_disable_msix(pdev);
1130         nvme_release_instance(dev);
1131  free:
1132         kfree(dev->queues);
1133         kfree(dev->entry);
1134         kfree(dev);
1135         return result;
1136 }
1137
1138 static void __devexit nvme_remove(struct pci_dev *pdev)
1139 {
1140         struct nvme_dev *dev = pci_get_drvdata(pdev);
1141         nvme_dev_remove(dev);
1142         pci_disable_msix(pdev);
1143         iounmap(dev->bar);
1144         nvme_release_instance(dev);
1145         kfree(dev->queues);
1146         kfree(dev->entry);
1147         kfree(dev);
1148 }
1149
1150 /* These functions are yet to be implemented */
1151 #define nvme_error_detected NULL
1152 #define nvme_dump_registers NULL
1153 #define nvme_link_reset NULL
1154 #define nvme_slot_reset NULL
1155 #define nvme_error_resume NULL
1156 #define nvme_suspend NULL
1157 #define nvme_resume NULL
1158
1159 static struct pci_error_handlers nvme_err_handler = {
1160         .error_detected = nvme_error_detected,
1161         .mmio_enabled   = nvme_dump_registers,
1162         .link_reset     = nvme_link_reset,
1163         .slot_reset     = nvme_slot_reset,
1164         .resume         = nvme_error_resume,
1165 };
1166
1167 /* Move to pci_ids.h later */
1168 #define PCI_CLASS_STORAGE_EXPRESS       0x010802
1169
1170 static DEFINE_PCI_DEVICE_TABLE(nvme_id_table) = {
1171         { PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
1172         { 0, }
1173 };
1174 MODULE_DEVICE_TABLE(pci, nvme_id_table);
1175
1176 static struct pci_driver nvme_driver = {
1177         .name           = "nvme",
1178         .id_table       = nvme_id_table,
1179         .probe          = nvme_probe,
1180         .remove         = __devexit_p(nvme_remove),
1181         .suspend        = nvme_suspend,
1182         .resume         = nvme_resume,
1183         .err_handler    = &nvme_err_handler,
1184 };
1185
1186 static int __init nvme_init(void)
1187 {
1188         int result;
1189
1190         nvme_major = register_blkdev(nvme_major, "nvme");
1191         if (nvme_major <= 0)
1192                 return -EBUSY;
1193
1194         result = pci_register_driver(&nvme_driver);
1195         if (!result)
1196                 return 0;
1197
1198         unregister_blkdev(nvme_major, "nvme");
1199         return result;
1200 }
1201
1202 static void __exit nvme_exit(void)
1203 {
1204         pci_unregister_driver(&nvme_driver);
1205         unregister_blkdev(nvme_major, "nvme");
1206 }
1207
1208 MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>");
1209 MODULE_LICENSE("GPL");
1210 MODULE_VERSION("0.1");
1211 module_init(nvme_init);
1212 module_exit(nvme_exit);