Linux 4.7-rc3
[deliverable/linux.git] / drivers / nvdimm / pmem.c
CommitLineData
9e853f23
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1/*
2 * Persistent Memory Driver
3 *
9f53f9fa 4 * Copyright (c) 2014-2015, Intel Corporation.
9e853f23
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5 * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
6 * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms and conditions of the GNU General Public License,
10 * version 2, as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 */
17
18#include <asm/cacheflush.h>
19#include <linux/blkdev.h>
20#include <linux/hdreg.h>
21#include <linux/init.h>
22#include <linux/platform_device.h>
23#include <linux/module.h>
24#include <linux/moduleparam.h>
b95f5f43 25#include <linux/badblocks.h>
9476df7d 26#include <linux/memremap.h>
32ab0a3f 27#include <linux/vmalloc.h>
34c0fd54 28#include <linux/pfn_t.h>
9e853f23 29#include <linux/slab.h>
61031952 30#include <linux/pmem.h>
9f53f9fa 31#include <linux/nd.h>
32ab0a3f 32#include "pfn.h"
9f53f9fa 33#include "nd.h"
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34
35struct pmem_device {
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36 /* One contiguous memory region per device */
37 phys_addr_t phys_addr;
32ab0a3f
DW
38 /* when non-zero this device is hosting a 'pfn' instance */
39 phys_addr_t data_offset;
c4544205 40 u64 pfn_flags;
61031952 41 void __pmem *virt_addr;
cfe30b87 42 /* immutable base size of the namespace */
9e853f23 43 size_t size;
cfe30b87
DW
44 /* trim size when namespace capacity has been section aligned */
45 u32 pfn_pad;
b95f5f43 46 struct badblocks bb;
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47};
48
59e64739
DW
49static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
50 unsigned int len)
51{
5a92289f 52 struct device *dev = pmem->bb.dev;
59e64739
DW
53 sector_t sector;
54 long cleared;
55
56 sector = (offset - pmem->data_offset) / 512;
57 cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
58
59 if (cleared > 0 && cleared / 512) {
60 dev_dbg(dev, "%s: %llx clear %ld sector%s\n",
61 __func__, (unsigned long long) sector,
62 cleared / 512, cleared / 512 > 1 ? "s" : "");
63 badblocks_clear(&pmem->bb, sector, cleared / 512);
64 }
65 invalidate_pmem(pmem->virt_addr + offset, len);
66}
67
e10624f8 68static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
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69 unsigned int len, unsigned int off, int rw,
70 sector_t sector)
71{
b5ebc8ec 72 int rc = 0;
59e64739 73 bool bad_pmem = false;
9e853f23 74 void *mem = kmap_atomic(page);
32ab0a3f 75 phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
61031952 76 void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
9e853f23 77
59e64739
DW
78 if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
79 bad_pmem = true;
80
9e853f23 81 if (rw == READ) {
59e64739 82 if (unlikely(bad_pmem))
b5ebc8ec
DW
83 rc = -EIO;
84 else {
fc0c2028 85 rc = memcpy_from_pmem(mem + off, pmem_addr, len);
b5ebc8ec
DW
86 flush_dcache_page(page);
87 }
9e853f23 88 } else {
0a370d26
DW
89 /*
90 * Note that we write the data both before and after
91 * clearing poison. The write before clear poison
92 * handles situations where the latest written data is
93 * preserved and the clear poison operation simply marks
94 * the address range as valid without changing the data.
95 * In this case application software can assume that an
96 * interrupted write will either return the new good
97 * data or an error.
98 *
99 * However, if pmem_clear_poison() leaves the data in an
100 * indeterminate state we need to perform the write
101 * after clear poison.
102 */
9e853f23 103 flush_dcache_page(page);
61031952 104 memcpy_to_pmem(pmem_addr, mem + off, len);
59e64739
DW
105 if (unlikely(bad_pmem)) {
106 pmem_clear_poison(pmem, pmem_off, len);
107 memcpy_to_pmem(pmem_addr, mem + off, len);
108 }
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109 }
110
111 kunmap_atomic(mem);
b5ebc8ec 112 return rc;
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113}
114
dece1635 115static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
9e853f23 116{
e10624f8 117 int rc = 0;
f0dc089c
DW
118 bool do_acct;
119 unsigned long start;
9e853f23 120 struct bio_vec bvec;
9e853f23 121 struct bvec_iter iter;
bd842b8c 122 struct pmem_device *pmem = q->queuedata;
9e853f23 123
f0dc089c 124 do_acct = nd_iostat_start(bio, &start);
e10624f8
DW
125 bio_for_each_segment(bvec, bio, iter) {
126 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
127 bvec.bv_offset, bio_data_dir(bio),
128 iter.bi_sector);
129 if (rc) {
130 bio->bi_error = rc;
131 break;
132 }
133 }
f0dc089c
DW
134 if (do_acct)
135 nd_iostat_end(bio, start);
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136
137 if (bio_data_dir(bio))
138 wmb_pmem();
139
4246a0b6 140 bio_endio(bio);
dece1635 141 return BLK_QC_T_NONE;
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142}
143
144static int pmem_rw_page(struct block_device *bdev, sector_t sector,
145 struct page *page, int rw)
146{
bd842b8c 147 struct pmem_device *pmem = bdev->bd_queue->queuedata;
e10624f8 148 int rc;
9e853f23 149
09cbfeaf 150 rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector);
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151 if (rw & WRITE)
152 wmb_pmem();
9e853f23 153
e10624f8
DW
154 /*
155 * The ->rw_page interface is subtle and tricky. The core
156 * retries on any error, so we can only invoke page_endio() in
157 * the successful completion case. Otherwise, we'll see crashes
158 * caused by double completion.
159 */
160 if (rc == 0)
161 page_endio(page, rw & WRITE, 0);
162
163 return rc;
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164}
165
166static long pmem_direct_access(struct block_device *bdev, sector_t sector,
0a70bd43 167 void __pmem **kaddr, pfn_t *pfn, long size)
9e853f23 168{
bd842b8c 169 struct pmem_device *pmem = bdev->bd_queue->queuedata;
32ab0a3f 170 resource_size_t offset = sector * 512 + pmem->data_offset;
589e75d1 171
0a70bd43
DW
172 if (unlikely(is_bad_pmem(&pmem->bb, sector, size)))
173 return -EIO;
e2e05394 174 *kaddr = pmem->virt_addr + offset;
34c0fd54 175 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
9e853f23 176
0a70bd43
DW
177 /*
178 * If badblocks are present, limit known good range to the
179 * requested range.
180 */
181 if (unlikely(pmem->bb.count))
182 return size;
cfe30b87 183 return pmem->size - pmem->pfn_pad - offset;
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184}
185
186static const struct block_device_operations pmem_fops = {
187 .owner = THIS_MODULE,
188 .rw_page = pmem_rw_page,
189 .direct_access = pmem_direct_access,
58138820 190 .revalidate_disk = nvdimm_revalidate_disk,
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191};
192
030b99e3
DW
193static void pmem_release_queue(void *q)
194{
195 blk_cleanup_queue(q);
196}
197
198void pmem_release_disk(void *disk)
199{
200 del_gendisk(disk);
201 put_disk(disk);
202}
203
200c79da
DW
204static int pmem_attach_disk(struct device *dev,
205 struct nd_namespace_common *ndns)
9e853f23 206{
200c79da
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207 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
208 struct vmem_altmap __altmap, *altmap = NULL;
209 struct resource *res = &nsio->res;
210 struct nd_pfn *nd_pfn = NULL;
211 int nid = dev_to_node(dev);
212 struct nd_pfn_sb *pfn_sb;
9e853f23 213 struct pmem_device *pmem;
200c79da 214 struct resource pfn_res;
468ded03 215 struct request_queue *q;
200c79da
DW
216 struct gendisk *disk;
217 void *addr;
218
219 /* while nsio_rw_bytes is active, parse a pfn info block if present */
220 if (is_nd_pfn(dev)) {
221 nd_pfn = to_nd_pfn(dev);
222 altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap);
223 if (IS_ERR(altmap))
224 return PTR_ERR(altmap);
225 }
226
227 /* we're attaching a block device, disable raw namespace access */
228 devm_nsio_disable(dev, nsio);
9e853f23 229
708ab62b 230 pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
9e853f23 231 if (!pmem)
200c79da 232 return -ENOMEM;
9e853f23 233
200c79da 234 dev_set_drvdata(dev, pmem);
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235 pmem->phys_addr = res->start;
236 pmem->size = resource_size(res);
96601adb 237 if (!arch_has_wmb_pmem())
61031952 238 dev_warn(dev, "unable to guarantee persistence of writes\n");
9e853f23 239
947df02d
DW
240 if (!devm_request_mem_region(dev, res->start, resource_size(res),
241 dev_name(dev))) {
242 dev_warn(dev, "could not reserve region %pR\n", res);
200c79da 243 return -EBUSY;
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244 }
245
468ded03
DW
246 q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
247 if (!q)
200c79da 248 return -ENOMEM;
468ded03 249
34c0fd54 250 pmem->pfn_flags = PFN_DEV;
200c79da
DW
251 if (is_nd_pfn(dev)) {
252 addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter,
253 altmap);
254 pfn_sb = nd_pfn->pfn_sb;
255 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
256 pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res);
257 pmem->pfn_flags |= PFN_MAP;
258 res = &pfn_res; /* for badblocks populate */
259 res->start += pmem->data_offset;
260 } else if (pmem_should_map_pages(dev)) {
261 addr = devm_memremap_pages(dev, &nsio->res,
5c2c2587 262 &q->q_usage_counter, NULL);
34c0fd54
DW
263 pmem->pfn_flags |= PFN_MAP;
264 } else
200c79da
DW
265 addr = devm_memremap(dev, pmem->phys_addr,
266 pmem->size, ARCH_MEMREMAP_PMEM);
b36f4761 267
030b99e3
DW
268 /*
269 * At release time the queue must be dead before
270 * devm_memremap_pages is unwound
271 */
272 if (devm_add_action(dev, pmem_release_queue, q)) {
468ded03 273 blk_cleanup_queue(q);
200c79da 274 return -ENOMEM;
468ded03 275 }
8c2f7e86 276
200c79da
DW
277 if (IS_ERR(addr))
278 return PTR_ERR(addr);
279 pmem->virt_addr = (void __pmem *) addr;
9e853f23 280
5a92289f
DW
281 blk_queue_make_request(q, pmem_make_request);
282 blk_queue_physical_block_size(q, PAGE_SIZE);
283 blk_queue_max_hw_sectors(q, UINT_MAX);
284 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
285 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
286 q->queuedata = pmem;
9e853f23 287
538ea4aa 288 disk = alloc_disk_node(0, nid);
030b99e3
DW
289 if (!disk)
290 return -ENOMEM;
291 if (devm_add_action(dev, pmem_release_disk, disk)) {
292 put_disk(disk);
8c2f7e86
DW
293 return -ENOMEM;
294 }
9e853f23 295
9e853f23 296 disk->fops = &pmem_fops;
5a92289f 297 disk->queue = q;
9e853f23 298 disk->flags = GENHD_FL_EXT_DEVT;
5212e11f 299 nvdimm_namespace_disk_name(ndns, disk->disk_name);
32ab0a3f 300 disk->driverfs_dev = dev;
cfe30b87
DW
301 set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
302 / 512);
b95f5f43
DW
303 if (devm_init_badblocks(dev, &pmem->bb))
304 return -ENOMEM;
200c79da 305 nvdimm_badblocks_populate(to_nd_region(dev->parent), &pmem->bb, res);
57f7f317 306 disk->bb = &pmem->bb;
9e853f23 307 add_disk(disk);
58138820 308 revalidate_disk(disk);
9e853f23 309
8c2f7e86
DW
310 return 0;
311}
9e853f23 312
9f53f9fa 313static int nd_pmem_probe(struct device *dev)
9e853f23 314{
8c2f7e86 315 struct nd_namespace_common *ndns;
9e853f23 316
8c2f7e86
DW
317 ndns = nvdimm_namespace_common_probe(dev);
318 if (IS_ERR(ndns))
319 return PTR_ERR(ndns);
bf9bccc1 320
200c79da
DW
321 if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
322 return -ENXIO;
708ab62b 323
200c79da 324 if (is_nd_btt(dev))
708ab62b
CH
325 return nvdimm_namespace_attach_btt(ndns);
326
32ab0a3f 327 if (is_nd_pfn(dev))
200c79da 328 return pmem_attach_disk(dev, ndns);
32ab0a3f 329
200c79da 330 /* if we find a valid info-block we'll come back as that personality */
c5ed9268
DW
331 if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
332 || nd_dax_probe(dev, ndns) == 0)
32ab0a3f 333 return -ENXIO;
32ab0a3f 334
200c79da
DW
335 /* ...otherwise we're just a raw pmem device */
336 return pmem_attach_disk(dev, ndns);
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337}
338
9f53f9fa 339static int nd_pmem_remove(struct device *dev)
9e853f23 340{
8c2f7e86 341 if (is_nd_btt(dev))
298f2bc5 342 nvdimm_namespace_detach_btt(to_nd_btt(dev));
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343 return 0;
344}
345
71999466
DW
346static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
347{
a3901802 348 struct nd_region *nd_region = to_nd_region(dev->parent);
298f2bc5
DW
349 struct pmem_device *pmem = dev_get_drvdata(dev);
350 resource_size_t offset = 0, end_trunc = 0;
351 struct nd_namespace_common *ndns;
352 struct nd_namespace_io *nsio;
353 struct resource res;
71999466
DW
354
355 if (event != NVDIMM_REVALIDATE_POISON)
356 return;
357
298f2bc5
DW
358 if (is_nd_btt(dev)) {
359 struct nd_btt *nd_btt = to_nd_btt(dev);
360
361 ndns = nd_btt->ndns;
362 } else if (is_nd_pfn(dev)) {
a3901802
DW
363 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
364 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
365
298f2bc5
DW
366 ndns = nd_pfn->ndns;
367 offset = pmem->data_offset + __le32_to_cpu(pfn_sb->start_pad);
368 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
369 } else
370 ndns = to_ndns(dev);
a3901802 371
298f2bc5
DW
372 nsio = to_nd_namespace_io(&ndns->dev);
373 res.start = nsio->res.start + offset;
374 res.end = nsio->res.end - end_trunc;
a3901802 375 nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);
71999466
DW
376}
377
9f53f9fa
DW
378MODULE_ALIAS("pmem");
379MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
bf9bccc1 380MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
9f53f9fa
DW
381static struct nd_device_driver nd_pmem_driver = {
382 .probe = nd_pmem_probe,
383 .remove = nd_pmem_remove,
71999466 384 .notify = nd_pmem_notify,
9f53f9fa
DW
385 .drv = {
386 .name = "nd_pmem",
9e853f23 387 },
bf9bccc1 388 .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
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389};
390
391static int __init pmem_init(void)
392{
55155291 393 return nd_driver_register(&nd_pmem_driver);
9e853f23
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394}
395module_init(pmem_init);
396
397static void pmem_exit(void)
398{
9f53f9fa 399 driver_unregister(&nd_pmem_driver.drv);
9e853f23
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400}
401module_exit(pmem_exit);
402
403MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
404MODULE_LICENSE("GPL v2");
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