]> git.karo-electronics.de Git - karo-tx-linux.git/blob - drivers/nvdimm/pmem.c
Merge back cpufreq core changes for v4.12.
[karo-tx-linux.git] / drivers / nvdimm / pmem.c
1 /*
2  * Persistent Memory Driver
3  *
4  * Copyright (c) 2014-2015, Intel Corporation.
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>
25 #include <linux/badblocks.h>
26 #include <linux/memremap.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pfn_t.h>
29 #include <linux/slab.h>
30 #include <linux/pmem.h>
31 #include <linux/nd.h>
32 #include "pmem.h"
33 #include "pfn.h"
34 #include "nd.h"
35
36 static struct device *to_dev(struct pmem_device *pmem)
37 {
38         /*
39          * nvdimm bus services need a 'dev' parameter, and we record the device
40          * at init in bb.dev.
41          */
42         return pmem->bb.dev;
43 }
44
45 static struct nd_region *to_region(struct pmem_device *pmem)
46 {
47         return to_nd_region(to_dev(pmem)->parent);
48 }
49
50 static int pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
51                 unsigned int len)
52 {
53         struct device *dev = to_dev(pmem);
54         sector_t sector;
55         long cleared;
56         int rc = 0;
57
58         sector = (offset - pmem->data_offset) / 512;
59
60         cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
61         if (cleared < len)
62                 rc = -EIO;
63         if (cleared > 0 && cleared / 512) {
64                 cleared /= 512;
65                 dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__,
66                                 (unsigned long long) sector, cleared,
67                                 cleared > 1 ? "s" : "");
68                 badblocks_clear(&pmem->bb, sector, cleared);
69         }
70
71         invalidate_pmem(pmem->virt_addr + offset, len);
72
73         return rc;
74 }
75
76 static void write_pmem(void *pmem_addr, struct page *page,
77                 unsigned int off, unsigned int len)
78 {
79         void *mem = kmap_atomic(page);
80
81         memcpy_to_pmem(pmem_addr, mem + off, len);
82         kunmap_atomic(mem);
83 }
84
85 static int read_pmem(struct page *page, unsigned int off,
86                 void *pmem_addr, unsigned int len)
87 {
88         int rc;
89         void *mem = kmap_atomic(page);
90
91         rc = memcpy_from_pmem(mem + off, pmem_addr, len);
92         kunmap_atomic(mem);
93         if (rc)
94                 return -EIO;
95         return 0;
96 }
97
98 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
99                         unsigned int len, unsigned int off, bool is_write,
100                         sector_t sector)
101 {
102         int rc = 0;
103         bool bad_pmem = false;
104         phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
105         void *pmem_addr = pmem->virt_addr + pmem_off;
106
107         if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
108                 bad_pmem = true;
109
110         if (!is_write) {
111                 if (unlikely(bad_pmem))
112                         rc = -EIO;
113                 else {
114                         rc = read_pmem(page, off, pmem_addr, len);
115                         flush_dcache_page(page);
116                 }
117         } else {
118                 /*
119                  * Note that we write the data both before and after
120                  * clearing poison.  The write before clear poison
121                  * handles situations where the latest written data is
122                  * preserved and the clear poison operation simply marks
123                  * the address range as valid without changing the data.
124                  * In this case application software can assume that an
125                  * interrupted write will either return the new good
126                  * data or an error.
127                  *
128                  * However, if pmem_clear_poison() leaves the data in an
129                  * indeterminate state we need to perform the write
130                  * after clear poison.
131                  */
132                 flush_dcache_page(page);
133                 write_pmem(pmem_addr, page, off, len);
134                 if (unlikely(bad_pmem)) {
135                         rc = pmem_clear_poison(pmem, pmem_off, len);
136                         write_pmem(pmem_addr, page, off, len);
137                 }
138         }
139
140         return rc;
141 }
142
143 /* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */
144 #ifndef REQ_FLUSH
145 #define REQ_FLUSH REQ_PREFLUSH
146 #endif
147
148 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
149 {
150         int rc = 0;
151         bool do_acct;
152         unsigned long start;
153         struct bio_vec bvec;
154         struct bvec_iter iter;
155         struct pmem_device *pmem = q->queuedata;
156         struct nd_region *nd_region = to_region(pmem);
157
158         if (bio->bi_opf & REQ_FLUSH)
159                 nvdimm_flush(nd_region);
160
161         do_acct = nd_iostat_start(bio, &start);
162         bio_for_each_segment(bvec, bio, iter) {
163                 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
164                                 bvec.bv_offset, op_is_write(bio_op(bio)),
165                                 iter.bi_sector);
166                 if (rc) {
167                         bio->bi_error = rc;
168                         break;
169                 }
170         }
171         if (do_acct)
172                 nd_iostat_end(bio, start);
173
174         if (bio->bi_opf & REQ_FUA)
175                 nvdimm_flush(nd_region);
176
177         bio_endio(bio);
178         return BLK_QC_T_NONE;
179 }
180
181 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
182                        struct page *page, bool is_write)
183 {
184         struct pmem_device *pmem = bdev->bd_queue->queuedata;
185         int rc;
186
187         rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector);
188
189         /*
190          * The ->rw_page interface is subtle and tricky.  The core
191          * retries on any error, so we can only invoke page_endio() in
192          * the successful completion case.  Otherwise, we'll see crashes
193          * caused by double completion.
194          */
195         if (rc == 0)
196                 page_endio(page, is_write, 0);
197
198         return rc;
199 }
200
201 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
202 __weak long pmem_direct_access(struct block_device *bdev, sector_t sector,
203                       void **kaddr, pfn_t *pfn, long size)
204 {
205         struct pmem_device *pmem = bdev->bd_queue->queuedata;
206         resource_size_t offset = sector * 512 + pmem->data_offset;
207
208         if (unlikely(is_bad_pmem(&pmem->bb, sector, size)))
209                 return -EIO;
210         *kaddr = pmem->virt_addr + offset;
211         *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
212
213         /*
214          * If badblocks are present, limit known good range to the
215          * requested range.
216          */
217         if (unlikely(pmem->bb.count))
218                 return size;
219         return pmem->size - pmem->pfn_pad - offset;
220 }
221
222 static const struct block_device_operations pmem_fops = {
223         .owner =                THIS_MODULE,
224         .rw_page =              pmem_rw_page,
225         .direct_access =        pmem_direct_access,
226         .revalidate_disk =      nvdimm_revalidate_disk,
227 };
228
229 static void pmem_release_queue(void *q)
230 {
231         blk_cleanup_queue(q);
232 }
233
234 static void pmem_release_disk(void *disk)
235 {
236         del_gendisk(disk);
237         put_disk(disk);
238 }
239
240 static int pmem_attach_disk(struct device *dev,
241                 struct nd_namespace_common *ndns)
242 {
243         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
244         struct nd_region *nd_region = to_nd_region(dev->parent);
245         struct vmem_altmap __altmap, *altmap = NULL;
246         struct resource *res = &nsio->res;
247         struct nd_pfn *nd_pfn = NULL;
248         int nid = dev_to_node(dev);
249         struct nd_pfn_sb *pfn_sb;
250         struct pmem_device *pmem;
251         struct resource pfn_res;
252         struct request_queue *q;
253         struct gendisk *disk;
254         void *addr;
255
256         /* while nsio_rw_bytes is active, parse a pfn info block if present */
257         if (is_nd_pfn(dev)) {
258                 nd_pfn = to_nd_pfn(dev);
259                 altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap);
260                 if (IS_ERR(altmap))
261                         return PTR_ERR(altmap);
262         }
263
264         /* we're attaching a block device, disable raw namespace access */
265         devm_nsio_disable(dev, nsio);
266
267         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
268         if (!pmem)
269                 return -ENOMEM;
270
271         dev_set_drvdata(dev, pmem);
272         pmem->phys_addr = res->start;
273         pmem->size = resource_size(res);
274         if (nvdimm_has_flush(nd_region) < 0)
275                 dev_warn(dev, "unable to guarantee persistence of writes\n");
276
277         if (!devm_request_mem_region(dev, res->start, resource_size(res),
278                                 dev_name(&ndns->dev))) {
279                 dev_warn(dev, "could not reserve region %pR\n", res);
280                 return -EBUSY;
281         }
282
283         q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
284         if (!q)
285                 return -ENOMEM;
286
287         pmem->pfn_flags = PFN_DEV;
288         if (is_nd_pfn(dev)) {
289                 addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter,
290                                 altmap);
291                 pfn_sb = nd_pfn->pfn_sb;
292                 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
293                 pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res);
294                 pmem->pfn_flags |= PFN_MAP;
295                 res = &pfn_res; /* for badblocks populate */
296                 res->start += pmem->data_offset;
297         } else if (pmem_should_map_pages(dev)) {
298                 addr = devm_memremap_pages(dev, &nsio->res,
299                                 &q->q_usage_counter, NULL);
300                 pmem->pfn_flags |= PFN_MAP;
301         } else
302                 addr = devm_memremap(dev, pmem->phys_addr,
303                                 pmem->size, ARCH_MEMREMAP_PMEM);
304
305         /*
306          * At release time the queue must be dead before
307          * devm_memremap_pages is unwound
308          */
309         if (devm_add_action_or_reset(dev, pmem_release_queue, q))
310                 return -ENOMEM;
311
312         if (IS_ERR(addr))
313                 return PTR_ERR(addr);
314         pmem->virt_addr = addr;
315
316         blk_queue_write_cache(q, true, true);
317         blk_queue_make_request(q, pmem_make_request);
318         blk_queue_physical_block_size(q, PAGE_SIZE);
319         blk_queue_max_hw_sectors(q, UINT_MAX);
320         blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
321         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
322         queue_flag_set_unlocked(QUEUE_FLAG_DAX, q);
323         q->queuedata = pmem;
324
325         disk = alloc_disk_node(0, nid);
326         if (!disk)
327                 return -ENOMEM;
328
329         disk->fops              = &pmem_fops;
330         disk->queue             = q;
331         disk->flags             = GENHD_FL_EXT_DEVT;
332         nvdimm_namespace_disk_name(ndns, disk->disk_name);
333         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
334                         / 512);
335         if (devm_init_badblocks(dev, &pmem->bb))
336                 return -ENOMEM;
337         nvdimm_badblocks_populate(nd_region, &pmem->bb, res);
338         disk->bb = &pmem->bb;
339         device_add_disk(dev, disk);
340
341         if (devm_add_action_or_reset(dev, pmem_release_disk, disk))
342                 return -ENOMEM;
343
344         revalidate_disk(disk);
345
346         return 0;
347 }
348
349 static int nd_pmem_probe(struct device *dev)
350 {
351         struct nd_namespace_common *ndns;
352
353         ndns = nvdimm_namespace_common_probe(dev);
354         if (IS_ERR(ndns))
355                 return PTR_ERR(ndns);
356
357         if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
358                 return -ENXIO;
359
360         if (is_nd_btt(dev))
361                 return nvdimm_namespace_attach_btt(ndns);
362
363         if (is_nd_pfn(dev))
364                 return pmem_attach_disk(dev, ndns);
365
366         /* if we find a valid info-block we'll come back as that personality */
367         if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
368                         || nd_dax_probe(dev, ndns) == 0)
369                 return -ENXIO;
370
371         /* ...otherwise we're just a raw pmem device */
372         return pmem_attach_disk(dev, ndns);
373 }
374
375 static int nd_pmem_remove(struct device *dev)
376 {
377         if (is_nd_btt(dev))
378                 nvdimm_namespace_detach_btt(to_nd_btt(dev));
379         nvdimm_flush(to_nd_region(dev->parent));
380
381         return 0;
382 }
383
384 static void nd_pmem_shutdown(struct device *dev)
385 {
386         nvdimm_flush(to_nd_region(dev->parent));
387 }
388
389 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
390 {
391         struct pmem_device *pmem = dev_get_drvdata(dev);
392         struct nd_region *nd_region = to_region(pmem);
393         resource_size_t offset = 0, end_trunc = 0;
394         struct nd_namespace_common *ndns;
395         struct nd_namespace_io *nsio;
396         struct resource res;
397
398         if (event != NVDIMM_REVALIDATE_POISON)
399                 return;
400
401         if (is_nd_btt(dev)) {
402                 struct nd_btt *nd_btt = to_nd_btt(dev);
403
404                 ndns = nd_btt->ndns;
405         } else if (is_nd_pfn(dev)) {
406                 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
407                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
408
409                 ndns = nd_pfn->ndns;
410                 offset = pmem->data_offset + __le32_to_cpu(pfn_sb->start_pad);
411                 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
412         } else
413                 ndns = to_ndns(dev);
414
415         nsio = to_nd_namespace_io(&ndns->dev);
416         res.start = nsio->res.start + offset;
417         res.end = nsio->res.end - end_trunc;
418         nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);
419 }
420
421 MODULE_ALIAS("pmem");
422 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
423 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
424 static struct nd_device_driver nd_pmem_driver = {
425         .probe = nd_pmem_probe,
426         .remove = nd_pmem_remove,
427         .notify = nd_pmem_notify,
428         .shutdown = nd_pmem_shutdown,
429         .drv = {
430                 .name = "nd_pmem",
431         },
432         .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
433 };
434
435 static int __init pmem_init(void)
436 {
437         return nd_driver_register(&nd_pmem_driver);
438 }
439 module_init(pmem_init);
440
441 static void pmem_exit(void)
442 {
443         driver_unregister(&nd_pmem_driver.drv);
444 }
445 module_exit(pmem_exit);
446
447 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
448 MODULE_LICENSE("GPL v2");