2 * Persistent Memory Driver
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>.
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.
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
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/blk-mq.h>
29 #include <linux/pfn_t.h>
30 #include <linux/slab.h>
31 #include <linux/pmem.h>
32 #include <linux/dax.h>
38 static struct device *to_dev(struct pmem_device *pmem)
41 * nvdimm bus services need a 'dev' parameter, and we record the device
47 static struct nd_region *to_region(struct pmem_device *pmem)
49 return to_nd_region(to_dev(pmem)->parent);
52 static int pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
55 struct device *dev = to_dev(pmem);
60 sector = (offset - pmem->data_offset) / 512;
62 cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
65 if (cleared > 0 && cleared / 512) {
67 dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__,
68 (unsigned long long) sector, cleared,
69 cleared > 1 ? "s" : "");
70 badblocks_clear(&pmem->bb, sector, cleared);
73 invalidate_pmem(pmem->virt_addr + offset, len);
78 static void write_pmem(void *pmem_addr, struct page *page,
79 unsigned int off, unsigned int len)
81 void *mem = kmap_atomic(page);
83 memcpy_to_pmem(pmem_addr, mem + off, len);
87 static int read_pmem(struct page *page, unsigned int off,
88 void *pmem_addr, unsigned int len)
91 void *mem = kmap_atomic(page);
93 rc = memcpy_mcsafe(mem + off, pmem_addr, len);
100 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
101 unsigned int len, unsigned int off, bool is_write,
105 bool bad_pmem = false;
106 phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
107 void *pmem_addr = pmem->virt_addr + pmem_off;
109 if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
113 if (unlikely(bad_pmem))
116 rc = read_pmem(page, off, pmem_addr, len);
117 flush_dcache_page(page);
121 * Note that we write the data both before and after
122 * clearing poison. The write before clear poison
123 * handles situations where the latest written data is
124 * preserved and the clear poison operation simply marks
125 * the address range as valid without changing the data.
126 * In this case application software can assume that an
127 * interrupted write will either return the new good
130 * However, if pmem_clear_poison() leaves the data in an
131 * indeterminate state we need to perform the write
132 * after clear poison.
134 flush_dcache_page(page);
135 write_pmem(pmem_addr, page, off, len);
136 if (unlikely(bad_pmem)) {
137 rc = pmem_clear_poison(pmem, pmem_off, len);
138 write_pmem(pmem_addr, page, off, len);
145 /* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */
147 #define REQ_FLUSH REQ_PREFLUSH
150 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
156 struct bvec_iter iter;
157 struct pmem_device *pmem = q->queuedata;
158 struct nd_region *nd_region = to_region(pmem);
160 if (bio->bi_opf & REQ_FLUSH)
161 nvdimm_flush(nd_region);
163 do_acct = nd_iostat_start(bio, &start);
164 bio_for_each_segment(bvec, bio, iter) {
165 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
166 bvec.bv_offset, op_is_write(bio_op(bio)),
174 nd_iostat_end(bio, start);
176 if (bio->bi_opf & REQ_FUA)
177 nvdimm_flush(nd_region);
180 return BLK_QC_T_NONE;
183 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
184 struct page *page, bool is_write)
186 struct pmem_device *pmem = bdev->bd_queue->queuedata;
189 rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector);
192 * The ->rw_page interface is subtle and tricky. The core
193 * retries on any error, so we can only invoke page_endio() in
194 * the successful completion case. Otherwise, we'll see crashes
195 * caused by double completion.
198 page_endio(page, is_write, 0);
203 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
204 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
205 long nr_pages, void **kaddr, pfn_t *pfn)
207 resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
209 if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
210 PFN_PHYS(nr_pages))))
212 *kaddr = pmem->virt_addr + offset;
213 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
216 * If badblocks are present, limit known good range to the
219 if (unlikely(pmem->bb.count))
221 return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
224 static const struct block_device_operations pmem_fops = {
225 .owner = THIS_MODULE,
226 .rw_page = pmem_rw_page,
227 .revalidate_disk = nvdimm_revalidate_disk,
230 static long pmem_dax_direct_access(struct dax_device *dax_dev,
231 pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
233 struct pmem_device *pmem = dax_get_private(dax_dev);
235 return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
238 static const struct dax_operations pmem_dax_ops = {
239 .direct_access = pmem_dax_direct_access,
242 static void pmem_release_queue(void *q)
244 blk_cleanup_queue(q);
247 static void pmem_freeze_queue(void *q)
249 blk_freeze_queue_start(q);
252 static void pmem_release_disk(void *__pmem)
254 struct pmem_device *pmem = __pmem;
256 kill_dax(pmem->dax_dev);
257 put_dax(pmem->dax_dev);
258 del_gendisk(pmem->disk);
259 put_disk(pmem->disk);
262 static int pmem_attach_disk(struct device *dev,
263 struct nd_namespace_common *ndns)
265 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
266 struct nd_region *nd_region = to_nd_region(dev->parent);
267 struct vmem_altmap __altmap, *altmap = NULL;
268 struct resource *res = &nsio->res;
269 struct nd_pfn *nd_pfn = NULL;
270 struct dax_device *dax_dev;
271 int nid = dev_to_node(dev);
272 struct nd_pfn_sb *pfn_sb;
273 struct pmem_device *pmem;
274 struct resource pfn_res;
275 struct request_queue *q;
276 struct gendisk *disk;
279 /* while nsio_rw_bytes is active, parse a pfn info block if present */
280 if (is_nd_pfn(dev)) {
281 nd_pfn = to_nd_pfn(dev);
282 altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap);
284 return PTR_ERR(altmap);
287 /* we're attaching a block device, disable raw namespace access */
288 devm_nsio_disable(dev, nsio);
290 pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
294 dev_set_drvdata(dev, pmem);
295 pmem->phys_addr = res->start;
296 pmem->size = resource_size(res);
297 if (nvdimm_has_flush(nd_region) < 0)
298 dev_warn(dev, "unable to guarantee persistence of writes\n");
300 if (!devm_request_mem_region(dev, res->start, resource_size(res),
301 dev_name(&ndns->dev))) {
302 dev_warn(dev, "could not reserve region %pR\n", res);
306 q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
310 if (devm_add_action_or_reset(dev, pmem_release_queue, q))
313 pmem->pfn_flags = PFN_DEV;
314 if (is_nd_pfn(dev)) {
315 addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter,
317 pfn_sb = nd_pfn->pfn_sb;
318 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
319 pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res);
320 pmem->pfn_flags |= PFN_MAP;
321 res = &pfn_res; /* for badblocks populate */
322 res->start += pmem->data_offset;
323 } else if (pmem_should_map_pages(dev)) {
324 addr = devm_memremap_pages(dev, &nsio->res,
325 &q->q_usage_counter, NULL);
326 pmem->pfn_flags |= PFN_MAP;
328 addr = devm_memremap(dev, pmem->phys_addr,
329 pmem->size, ARCH_MEMREMAP_PMEM);
332 * At release time the queue must be frozen before
333 * devm_memremap_pages is unwound
335 if (devm_add_action_or_reset(dev, pmem_freeze_queue, q))
339 return PTR_ERR(addr);
340 pmem->virt_addr = addr;
342 blk_queue_write_cache(q, true, true);
343 blk_queue_make_request(q, pmem_make_request);
344 blk_queue_physical_block_size(q, PAGE_SIZE);
345 blk_queue_max_hw_sectors(q, UINT_MAX);
346 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
347 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
348 queue_flag_set_unlocked(QUEUE_FLAG_DAX, q);
351 disk = alloc_disk_node(0, nid);
356 disk->fops = &pmem_fops;
358 disk->flags = GENHD_FL_EXT_DEVT;
359 nvdimm_namespace_disk_name(ndns, disk->disk_name);
360 set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
362 if (devm_init_badblocks(dev, &pmem->bb))
364 nvdimm_badblocks_populate(nd_region, &pmem->bb, res);
365 disk->bb = &pmem->bb;
367 dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
372 pmem->dax_dev = dax_dev;
374 device_add_disk(dev, disk);
375 if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
378 revalidate_disk(disk);
383 static int nd_pmem_probe(struct device *dev)
385 struct nd_namespace_common *ndns;
387 ndns = nvdimm_namespace_common_probe(dev);
389 return PTR_ERR(ndns);
391 if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
395 return nvdimm_namespace_attach_btt(ndns);
398 return pmem_attach_disk(dev, ndns);
400 /* if we find a valid info-block we'll come back as that personality */
401 if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
402 || nd_dax_probe(dev, ndns) == 0)
405 /* ...otherwise we're just a raw pmem device */
406 return pmem_attach_disk(dev, ndns);
409 static int nd_pmem_remove(struct device *dev)
412 nvdimm_namespace_detach_btt(to_nd_btt(dev));
413 nvdimm_flush(to_nd_region(dev->parent));
418 static void nd_pmem_shutdown(struct device *dev)
420 nvdimm_flush(to_nd_region(dev->parent));
423 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
425 struct nd_region *nd_region;
426 resource_size_t offset = 0, end_trunc = 0;
427 struct nd_namespace_common *ndns;
428 struct nd_namespace_io *nsio;
430 struct badblocks *bb;
432 if (event != NVDIMM_REVALIDATE_POISON)
435 if (is_nd_btt(dev)) {
436 struct nd_btt *nd_btt = to_nd_btt(dev);
439 nd_region = to_nd_region(ndns->dev.parent);
440 nsio = to_nd_namespace_io(&ndns->dev);
443 struct pmem_device *pmem = dev_get_drvdata(dev);
445 nd_region = to_region(pmem);
448 if (is_nd_pfn(dev)) {
449 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
450 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
453 offset = pmem->data_offset +
454 __le32_to_cpu(pfn_sb->start_pad);
455 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
460 nsio = to_nd_namespace_io(&ndns->dev);
463 res.start = nsio->res.start + offset;
464 res.end = nsio->res.end - end_trunc;
465 nvdimm_badblocks_populate(nd_region, bb, &res);
468 MODULE_ALIAS("pmem");
469 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
470 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
471 static struct nd_device_driver nd_pmem_driver = {
472 .probe = nd_pmem_probe,
473 .remove = nd_pmem_remove,
474 .notify = nd_pmem_notify,
475 .shutdown = nd_pmem_shutdown,
479 .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
482 static int __init pmem_init(void)
484 return nd_driver_register(&nd_pmem_driver);
486 module_init(pmem_init);
488 static void pmem_exit(void)
490 driver_unregister(&nd_pmem_driver.drv);
492 module_exit(pmem_exit);
494 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
495 MODULE_LICENSE("GPL v2");