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047fc8a1 RZ |
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 | }; | |
31 | ||
32 | static int nd_blk_major; | |
33 | ||
34 | static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk, | |
35 | resource_size_t ns_offset, unsigned int len) | |
36 | { | |
37 | int i; | |
38 | ||
39 | for (i = 0; i < nsblk->num_resources; i++) { | |
40 | if (ns_offset < resource_size(nsblk->res[i])) { | |
41 | if (ns_offset + len > resource_size(nsblk->res[i])) { | |
42 | dev_WARN_ONCE(&nsblk->common.dev, 1, | |
43 | "illegal request\n"); | |
44 | return SIZE_MAX; | |
45 | } | |
46 | return nsblk->res[i]->start + ns_offset; | |
47 | } | |
48 | ns_offset -= resource_size(nsblk->res[i]); | |
49 | } | |
50 | ||
51 | dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n"); | |
52 | return SIZE_MAX; | |
53 | } | |
54 | ||
55 | static void nd_blk_make_request(struct request_queue *q, struct bio *bio) | |
56 | { | |
57 | struct block_device *bdev = bio->bi_bdev; | |
58 | struct gendisk *disk = bdev->bd_disk; | |
59 | struct nd_namespace_blk *nsblk; | |
60 | struct nd_blk_device *blk_dev; | |
61 | struct nd_blk_region *ndbr; | |
62 | struct bvec_iter iter; | |
63 | struct bio_vec bvec; | |
64 | int err = 0, rw; | |
65 | ||
66 | blk_dev = disk->private_data; | |
67 | nsblk = blk_dev->nsblk; | |
68 | ndbr = blk_dev->ndbr; | |
69 | rw = bio_data_dir(bio); | |
70 | bio_for_each_segment(bvec, bio, iter) { | |
71 | unsigned int len = bvec.bv_len; | |
72 | resource_size_t dev_offset; | |
73 | void *iobuf; | |
74 | ||
75 | BUG_ON(len > PAGE_SIZE); | |
76 | ||
77 | dev_offset = to_dev_offset(nsblk, | |
78 | iter.bi_sector << SECTOR_SHIFT, len); | |
79 | if (dev_offset == SIZE_MAX) { | |
80 | err = -EIO; | |
81 | goto out; | |
82 | } | |
83 | ||
84 | iobuf = kmap_atomic(bvec.bv_page); | |
85 | err = ndbr->do_io(ndbr, dev_offset, iobuf + bvec.bv_offset, | |
86 | len, rw); | |
87 | kunmap_atomic(iobuf); | |
88 | if (err) | |
89 | goto out; | |
90 | } | |
91 | ||
92 | out: | |
93 | bio_endio(bio, err); | |
94 | } | |
95 | ||
96 | static int nd_blk_rw_bytes(struct nd_namespace_common *ndns, | |
97 | resource_size_t offset, void *iobuf, size_t n, int rw) | |
98 | { | |
99 | struct nd_blk_device *blk_dev = dev_get_drvdata(ndns->claim); | |
100 | struct nd_namespace_blk *nsblk = blk_dev->nsblk; | |
101 | struct nd_blk_region *ndbr = blk_dev->ndbr; | |
102 | resource_size_t dev_offset; | |
103 | ||
104 | dev_offset = to_dev_offset(nsblk, offset, n); | |
105 | ||
106 | if (unlikely(offset + n > blk_dev->disk_size)) { | |
107 | dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n"); | |
108 | return -EFAULT; | |
109 | } | |
110 | ||
111 | if (dev_offset == SIZE_MAX) | |
112 | return -EIO; | |
113 | ||
114 | return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw); | |
115 | } | |
116 | ||
117 | static const struct block_device_operations nd_blk_fops = { | |
118 | .owner = THIS_MODULE, | |
119 | }; | |
120 | ||
121 | static int nd_blk_attach_disk(struct nd_namespace_common *ndns, | |
122 | struct nd_blk_device *blk_dev) | |
123 | { | |
124 | struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev); | |
125 | struct gendisk *disk; | |
126 | ||
127 | blk_dev->queue = blk_alloc_queue(GFP_KERNEL); | |
128 | if (!blk_dev->queue) | |
129 | return -ENOMEM; | |
130 | ||
131 | blk_queue_make_request(blk_dev->queue, nd_blk_make_request); | |
132 | blk_queue_max_hw_sectors(blk_dev->queue, UINT_MAX); | |
133 | blk_queue_bounce_limit(blk_dev->queue, BLK_BOUNCE_ANY); | |
134 | blk_queue_logical_block_size(blk_dev->queue, nsblk->lbasize); | |
135 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, blk_dev->queue); | |
136 | ||
137 | disk = blk_dev->disk = alloc_disk(0); | |
138 | if (!disk) { | |
139 | blk_cleanup_queue(blk_dev->queue); | |
140 | return -ENOMEM; | |
141 | } | |
142 | ||
143 | disk->driverfs_dev = &ndns->dev; | |
144 | disk->major = nd_blk_major; | |
145 | disk->first_minor = 0; | |
146 | disk->fops = &nd_blk_fops; | |
147 | disk->private_data = blk_dev; | |
148 | disk->queue = blk_dev->queue; | |
149 | disk->flags = GENHD_FL_EXT_DEVT; | |
150 | nvdimm_namespace_disk_name(ndns, disk->disk_name); | |
151 | set_capacity(disk, blk_dev->disk_size >> SECTOR_SHIFT); | |
152 | add_disk(disk); | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
157 | static int nd_blk_probe(struct device *dev) | |
158 | { | |
159 | struct nd_namespace_common *ndns; | |
160 | struct nd_blk_device *blk_dev; | |
161 | int rc; | |
162 | ||
163 | ndns = nvdimm_namespace_common_probe(dev); | |
164 | if (IS_ERR(ndns)) | |
165 | return PTR_ERR(ndns); | |
166 | ||
167 | blk_dev = kzalloc(sizeof(*blk_dev), GFP_KERNEL); | |
168 | if (!blk_dev) | |
169 | return -ENOMEM; | |
170 | ||
171 | blk_dev->disk_size = nvdimm_namespace_capacity(ndns); | |
172 | blk_dev->ndbr = to_nd_blk_region(dev->parent); | |
173 | blk_dev->nsblk = to_nd_namespace_blk(&ndns->dev); | |
174 | dev_set_drvdata(dev, blk_dev); | |
175 | ||
176 | ndns->rw_bytes = nd_blk_rw_bytes; | |
177 | if (is_nd_btt(dev)) | |
178 | rc = nvdimm_namespace_attach_btt(ndns); | |
179 | else if (nd_btt_probe(ndns, blk_dev) == 0) { | |
180 | /* we'll come back as btt-blk */ | |
181 | rc = -ENXIO; | |
182 | } else | |
183 | rc = nd_blk_attach_disk(ndns, blk_dev); | |
184 | if (rc) | |
185 | kfree(blk_dev); | |
186 | return rc; | |
187 | } | |
188 | ||
189 | static void nd_blk_detach_disk(struct nd_blk_device *blk_dev) | |
190 | { | |
191 | del_gendisk(blk_dev->disk); | |
192 | put_disk(blk_dev->disk); | |
193 | blk_cleanup_queue(blk_dev->queue); | |
194 | } | |
195 | ||
196 | static int nd_blk_remove(struct device *dev) | |
197 | { | |
198 | struct nd_blk_device *blk_dev = dev_get_drvdata(dev); | |
199 | ||
200 | if (is_nd_btt(dev)) | |
201 | nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns); | |
202 | else | |
203 | nd_blk_detach_disk(blk_dev); | |
204 | kfree(blk_dev); | |
205 | ||
206 | return 0; | |
207 | } | |
208 | ||
209 | static struct nd_device_driver nd_blk_driver = { | |
210 | .probe = nd_blk_probe, | |
211 | .remove = nd_blk_remove, | |
212 | .drv = { | |
213 | .name = "nd_blk", | |
214 | }, | |
215 | .type = ND_DRIVER_NAMESPACE_BLK, | |
216 | }; | |
217 | ||
218 | static int __init nd_blk_init(void) | |
219 | { | |
220 | int rc; | |
221 | ||
222 | rc = register_blkdev(0, "nd_blk"); | |
223 | if (rc < 0) | |
224 | return rc; | |
225 | ||
226 | nd_blk_major = rc; | |
227 | rc = nd_driver_register(&nd_blk_driver); | |
228 | ||
229 | if (rc < 0) | |
230 | unregister_blkdev(nd_blk_major, "nd_blk"); | |
231 | ||
232 | return rc; | |
233 | } | |
234 | ||
235 | static void __exit nd_blk_exit(void) | |
236 | { | |
237 | driver_unregister(&nd_blk_driver.drv); | |
238 | unregister_blkdev(nd_blk_major, "nd_blk"); | |
239 | } | |
240 | ||
241 | MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>"); | |
242 | MODULE_LICENSE("GPL v2"); | |
243 | MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK); | |
244 | module_init(nd_blk_init); | |
245 | module_exit(nd_blk_exit); |