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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[karo-tx-linux.git] / drivers / nvdimm / blk.c
1 /*
2  * NVDIMM Block Window Driver
3  * Copyright (c) 2014, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  */
14
15 #include <linux/blkdev.h>
16 #include <linux/fs.h>
17 #include <linux/genhd.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/nd.h>
21 #include <linux/sizes.h>
22 #include "nd.h"
23
24 struct nd_blk_device {
25         struct request_queue *queue;
26         struct gendisk *disk;
27         struct nd_namespace_blk *nsblk;
28         struct nd_blk_region *ndbr;
29         size_t disk_size;
30         u32 sector_size;
31         u32 internal_lbasize;
32 };
33
34 static u32 nd_blk_meta_size(struct nd_blk_device *blk_dev)
35 {
36         return blk_dev->nsblk->lbasize - blk_dev->sector_size;
37 }
38
39 static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
40                                 resource_size_t ns_offset, unsigned int len)
41 {
42         int i;
43
44         for (i = 0; i < nsblk->num_resources; i++) {
45                 if (ns_offset < resource_size(nsblk->res[i])) {
46                         if (ns_offset + len > resource_size(nsblk->res[i])) {
47                                 dev_WARN_ONCE(&nsblk->common.dev, 1,
48                                         "illegal request\n");
49                                 return SIZE_MAX;
50                         }
51                         return nsblk->res[i]->start + ns_offset;
52                 }
53                 ns_offset -= resource_size(nsblk->res[i]);
54         }
55
56         dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n");
57         return SIZE_MAX;
58 }
59
60 #ifdef CONFIG_BLK_DEV_INTEGRITY
61 static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
62                                 struct bio_integrity_payload *bip, u64 lba,
63                                 int rw)
64 {
65         unsigned int len = nd_blk_meta_size(blk_dev);
66         resource_size_t dev_offset, ns_offset;
67         struct nd_namespace_blk *nsblk;
68         struct nd_blk_region *ndbr;
69         int err = 0;
70
71         nsblk = blk_dev->nsblk;
72         ndbr = blk_dev->ndbr;
73         ns_offset = lba * blk_dev->internal_lbasize + blk_dev->sector_size;
74         dev_offset = to_dev_offset(nsblk, ns_offset, len);
75         if (dev_offset == SIZE_MAX)
76                 return -EIO;
77
78         while (len) {
79                 unsigned int cur_len;
80                 struct bio_vec bv;
81                 void *iobuf;
82
83                 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
84                 /*
85                  * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
86                  * .bv_offset already adjusted for iter->bi_bvec_done, and we
87                  * can use those directly
88                  */
89
90                 cur_len = min(len, bv.bv_len);
91                 iobuf = kmap_atomic(bv.bv_page);
92                 err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
93                                 cur_len, rw);
94                 kunmap_atomic(iobuf);
95                 if (err)
96                         return err;
97
98                 len -= cur_len;
99                 dev_offset += cur_len;
100                 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
101         }
102
103         return err;
104 }
105
106 #else /* CONFIG_BLK_DEV_INTEGRITY */
107 static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
108                                 struct bio_integrity_payload *bip, u64 lba,
109                                 int rw)
110 {
111         return 0;
112 }
113 #endif
114
115 static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
116                         struct bio_integrity_payload *bip, struct page *page,
117                         unsigned int len, unsigned int off, int rw,
118                         sector_t sector)
119 {
120         struct nd_blk_region *ndbr = blk_dev->ndbr;
121         resource_size_t dev_offset, ns_offset;
122         int err = 0;
123         void *iobuf;
124         u64 lba;
125
126         while (len) {
127                 unsigned int cur_len;
128
129                 /*
130                  * If we don't have an integrity payload, we don't have to
131                  * split the bvec into sectors, as this would cause unnecessary
132                  * Block Window setup/move steps. the do_io routine is capable
133                  * of handling len <= PAGE_SIZE.
134                  */
135                 cur_len = bip ? min(len, blk_dev->sector_size) : len;
136
137                 lba = div_u64(sector << SECTOR_SHIFT, blk_dev->sector_size);
138                 ns_offset = lba * blk_dev->internal_lbasize;
139                 dev_offset = to_dev_offset(blk_dev->nsblk, ns_offset, cur_len);
140                 if (dev_offset == SIZE_MAX)
141                         return -EIO;
142
143                 iobuf = kmap_atomic(page);
144                 err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
145                 kunmap_atomic(iobuf);
146                 if (err)
147                         return err;
148
149                 if (bip) {
150                         err = nd_blk_rw_integrity(blk_dev, bip, lba, rw);
151                         if (err)
152                                 return err;
153                 }
154                 len -= cur_len;
155                 off += cur_len;
156                 sector += blk_dev->sector_size >> SECTOR_SHIFT;
157         }
158
159         return err;
160 }
161
162 static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
163 {
164         struct block_device *bdev = bio->bi_bdev;
165         struct gendisk *disk = bdev->bd_disk;
166         struct bio_integrity_payload *bip;
167         struct nd_blk_device *blk_dev;
168         struct bvec_iter iter;
169         unsigned long start;
170         struct bio_vec bvec;
171         int err = 0, rw;
172         bool do_acct;
173
174         /*
175          * bio_integrity_enabled also checks if the bio already has an
176          * integrity payload attached. If it does, we *don't* do a
177          * bio_integrity_prep here - the payload has been generated by
178          * another kernel subsystem, and we just pass it through.
179          */
180         if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
181                 bio->bi_error = -EIO;
182                 goto out;
183         }
184
185         bip = bio_integrity(bio);
186         blk_dev = disk->private_data;
187         rw = bio_data_dir(bio);
188         do_acct = nd_iostat_start(bio, &start);
189         bio_for_each_segment(bvec, bio, iter) {
190                 unsigned int len = bvec.bv_len;
191
192                 BUG_ON(len > PAGE_SIZE);
193                 err = nd_blk_do_bvec(blk_dev, bip, bvec.bv_page, len,
194                                         bvec.bv_offset, rw, iter.bi_sector);
195                 if (err) {
196                         dev_info(&blk_dev->nsblk->common.dev,
197                                         "io error in %s sector %lld, len %d,\n",
198                                         (rw == READ) ? "READ" : "WRITE",
199                                         (unsigned long long) iter.bi_sector, len);
200                         bio->bi_error = err;
201                         break;
202                 }
203         }
204         if (do_acct)
205                 nd_iostat_end(bio, start);
206
207  out:
208         bio_endio(bio);
209         return BLK_QC_T_NONE;
210 }
211
212 static int nd_blk_rw_bytes(struct nd_namespace_common *ndns,
213                 resource_size_t offset, void *iobuf, size_t n, int rw)
214 {
215         struct nd_blk_device *blk_dev = dev_get_drvdata(ndns->claim);
216         struct nd_namespace_blk *nsblk = blk_dev->nsblk;
217         struct nd_blk_region *ndbr = blk_dev->ndbr;
218         resource_size_t dev_offset;
219
220         dev_offset = to_dev_offset(nsblk, offset, n);
221
222         if (unlikely(offset + n > blk_dev->disk_size)) {
223                 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
224                 return -EFAULT;
225         }
226
227         if (dev_offset == SIZE_MAX)
228                 return -EIO;
229
230         return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
231 }
232
233 static const struct block_device_operations nd_blk_fops = {
234         .owner = THIS_MODULE,
235         .revalidate_disk = nvdimm_revalidate_disk,
236 };
237
238 static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
239                 struct nd_blk_device *blk_dev)
240 {
241         resource_size_t available_disk_size;
242         struct gendisk *disk;
243         u64 internal_nlba;
244
245         internal_nlba = div_u64(blk_dev->disk_size, blk_dev->internal_lbasize);
246         available_disk_size = internal_nlba * blk_dev->sector_size;
247
248         blk_dev->queue = blk_alloc_queue(GFP_KERNEL);
249         if (!blk_dev->queue)
250                 return -ENOMEM;
251
252         blk_queue_make_request(blk_dev->queue, nd_blk_make_request);
253         blk_queue_max_hw_sectors(blk_dev->queue, UINT_MAX);
254         blk_queue_bounce_limit(blk_dev->queue, BLK_BOUNCE_ANY);
255         blk_queue_logical_block_size(blk_dev->queue, blk_dev->sector_size);
256         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, blk_dev->queue);
257
258         disk = blk_dev->disk = alloc_disk(0);
259         if (!disk) {
260                 blk_cleanup_queue(blk_dev->queue);
261                 return -ENOMEM;
262         }
263
264         disk->driverfs_dev      = &ndns->dev;
265         disk->first_minor       = 0;
266         disk->fops              = &nd_blk_fops;
267         disk->private_data      = blk_dev;
268         disk->queue             = blk_dev->queue;
269         disk->flags             = GENHD_FL_EXT_DEVT;
270         nvdimm_namespace_disk_name(ndns, disk->disk_name);
271         set_capacity(disk, 0);
272         add_disk(disk);
273
274         if (nd_blk_meta_size(blk_dev)) {
275                 int rc = nd_integrity_init(disk, nd_blk_meta_size(blk_dev));
276
277                 if (rc) {
278                         del_gendisk(disk);
279                         put_disk(disk);
280                         blk_cleanup_queue(blk_dev->queue);
281                         return rc;
282                 }
283         }
284
285         set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
286         revalidate_disk(disk);
287         return 0;
288 }
289
290 static int nd_blk_probe(struct device *dev)
291 {
292         struct nd_namespace_common *ndns;
293         struct nd_namespace_blk *nsblk;
294         struct nd_blk_device *blk_dev;
295         int rc;
296
297         ndns = nvdimm_namespace_common_probe(dev);
298         if (IS_ERR(ndns))
299                 return PTR_ERR(ndns);
300
301         blk_dev = kzalloc(sizeof(*blk_dev), GFP_KERNEL);
302         if (!blk_dev)
303                 return -ENOMEM;
304
305         nsblk = to_nd_namespace_blk(&ndns->dev);
306         blk_dev->disk_size = nvdimm_namespace_capacity(ndns);
307         blk_dev->ndbr = to_nd_blk_region(dev->parent);
308         blk_dev->nsblk = to_nd_namespace_blk(&ndns->dev);
309         blk_dev->internal_lbasize = roundup(nsblk->lbasize,
310                                                 INT_LBASIZE_ALIGNMENT);
311         blk_dev->sector_size = ((nsblk->lbasize >= 4096) ? 4096 : 512);
312         dev_set_drvdata(dev, blk_dev);
313
314         ndns->rw_bytes = nd_blk_rw_bytes;
315         if (is_nd_btt(dev))
316                 rc = nvdimm_namespace_attach_btt(ndns);
317         else if (nd_btt_probe(ndns, blk_dev) == 0) {
318                 /* we'll come back as btt-blk */
319                 rc = -ENXIO;
320         } else
321                 rc = nd_blk_attach_disk(ndns, blk_dev);
322         if (rc)
323                 kfree(blk_dev);
324         return rc;
325 }
326
327 static void nd_blk_detach_disk(struct nd_blk_device *blk_dev)
328 {
329         del_gendisk(blk_dev->disk);
330         put_disk(blk_dev->disk);
331         blk_cleanup_queue(blk_dev->queue);
332 }
333
334 static int nd_blk_remove(struct device *dev)
335 {
336         struct nd_blk_device *blk_dev = dev_get_drvdata(dev);
337
338         if (is_nd_btt(dev))
339                 nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
340         else
341                 nd_blk_detach_disk(blk_dev);
342         kfree(blk_dev);
343
344         return 0;
345 }
346
347 static struct nd_device_driver nd_blk_driver = {
348         .probe = nd_blk_probe,
349         .remove = nd_blk_remove,
350         .drv = {
351                 .name = "nd_blk",
352         },
353         .type = ND_DRIVER_NAMESPACE_BLK,
354 };
355
356 static int __init nd_blk_init(void)
357 {
358         return nd_driver_register(&nd_blk_driver);
359 }
360
361 static void __exit nd_blk_exit(void)
362 {
363         driver_unregister(&nd_blk_driver.drv);
364 }
365
366 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
367 MODULE_LICENSE("GPL v2");
368 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
369 module_init(nd_blk_init);
370 module_exit(nd_blk_exit);