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/pfn_t.h>
29 #include <linux/slab.h>
30 #include <linux/pmem.h>
36 static struct device *to_dev(struct pmem_device *pmem)
39 * nvdimm bus services need a 'dev' parameter, and we record the device
45 static struct nd_region *to_region(struct pmem_device *pmem)
47 return to_nd_region(to_dev(pmem)->parent);
50 static int pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
53 struct device *dev = to_dev(pmem);
57 sector = (offset - pmem->data_offset) / 512;
58 cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
60 if (cleared > 0 && cleared / 512) {
61 dev_dbg(dev, "%s: %#llx clear %ld sector%s\n",
62 __func__, (unsigned long long) sector,
63 cleared / 512, cleared / 512 > 1 ? "s" : "");
64 badblocks_clear(&pmem->bb, sector, cleared / 512);
69 invalidate_pmem(pmem->virt_addr + offset, len);
73 static void write_pmem(void *pmem_addr, struct page *page,
74 unsigned int off, unsigned int len)
76 void *mem = kmap_atomic(page);
78 memcpy_to_pmem(pmem_addr, mem + off, len);
82 static int read_pmem(struct page *page, unsigned int off,
83 void *pmem_addr, unsigned int len)
86 void *mem = kmap_atomic(page);
88 rc = memcpy_from_pmem(mem + off, pmem_addr, len);
93 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
94 unsigned int len, unsigned int off, bool is_write,
98 bool bad_pmem = false;
99 phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
100 void *pmem_addr = pmem->virt_addr + pmem_off;
102 if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
106 if (unlikely(bad_pmem))
109 rc = read_pmem(page, off, pmem_addr, len);
110 flush_dcache_page(page);
114 * Note that we write the data both before and after
115 * clearing poison. The write before clear poison
116 * handles situations where the latest written data is
117 * preserved and the clear poison operation simply marks
118 * the address range as valid without changing the data.
119 * In this case application software can assume that an
120 * interrupted write will either return the new good
123 * However, if pmem_clear_poison() leaves the data in an
124 * indeterminate state we need to perform the write
125 * after clear poison.
127 flush_dcache_page(page);
128 write_pmem(pmem_addr, page, off, len);
129 if (unlikely(bad_pmem)) {
130 rc = pmem_clear_poison(pmem, pmem_off, len);
131 write_pmem(pmem_addr, page, off, len);
138 /* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */
140 #define REQ_FLUSH REQ_PREFLUSH
143 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
149 struct bvec_iter iter;
150 struct pmem_device *pmem = q->queuedata;
151 struct nd_region *nd_region = to_region(pmem);
153 if (bio->bi_opf & REQ_FLUSH)
154 nvdimm_flush(nd_region);
156 do_acct = nd_iostat_start(bio, &start);
157 bio_for_each_segment(bvec, bio, iter) {
158 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
159 bvec.bv_offset, op_is_write(bio_op(bio)),
167 nd_iostat_end(bio, start);
169 if (bio->bi_opf & REQ_FUA)
170 nvdimm_flush(nd_region);
173 return BLK_QC_T_NONE;
176 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
177 struct page *page, bool is_write)
179 struct pmem_device *pmem = bdev->bd_queue->queuedata;
182 rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector);
185 * The ->rw_page interface is subtle and tricky. The core
186 * retries on any error, so we can only invoke page_endio() in
187 * the successful completion case. Otherwise, we'll see crashes
188 * caused by double completion.
191 page_endio(page, is_write, 0);
196 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
197 __weak long pmem_direct_access(struct block_device *bdev, sector_t sector,
198 void **kaddr, pfn_t *pfn, long size)
200 struct pmem_device *pmem = bdev->bd_queue->queuedata;
201 resource_size_t offset = sector * 512 + pmem->data_offset;
203 if (unlikely(is_bad_pmem(&pmem->bb, sector, size)))
205 *kaddr = pmem->virt_addr + offset;
206 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
209 * If badblocks are present, limit known good range to the
212 if (unlikely(pmem->bb.count))
214 return pmem->size - pmem->pfn_pad - offset;
217 static const struct block_device_operations pmem_fops = {
218 .owner = THIS_MODULE,
219 .rw_page = pmem_rw_page,
220 .direct_access = pmem_direct_access,
221 .revalidate_disk = nvdimm_revalidate_disk,
224 static void pmem_release_queue(void *q)
226 blk_cleanup_queue(q);
229 static void pmem_release_disk(void *disk)
235 static int pmem_attach_disk(struct device *dev,
236 struct nd_namespace_common *ndns)
238 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
239 struct nd_region *nd_region = to_nd_region(dev->parent);
240 struct vmem_altmap __altmap, *altmap = NULL;
241 struct resource *res = &nsio->res;
242 struct nd_pfn *nd_pfn = NULL;
243 int nid = dev_to_node(dev);
244 struct nd_pfn_sb *pfn_sb;
245 struct pmem_device *pmem;
246 struct resource pfn_res;
247 struct request_queue *q;
248 struct gendisk *disk;
251 /* while nsio_rw_bytes is active, parse a pfn info block if present */
252 if (is_nd_pfn(dev)) {
253 nd_pfn = to_nd_pfn(dev);
254 altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap);
256 return PTR_ERR(altmap);
259 /* we're attaching a block device, disable raw namespace access */
260 devm_nsio_disable(dev, nsio);
262 pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
266 dev_set_drvdata(dev, pmem);
267 pmem->phys_addr = res->start;
268 pmem->size = resource_size(res);
269 if (nvdimm_has_flush(nd_region) < 0)
270 dev_warn(dev, "unable to guarantee persistence of writes\n");
272 if (!devm_request_mem_region(dev, res->start, resource_size(res),
274 dev_warn(dev, "could not reserve region %pR\n", res);
278 q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
282 pmem->pfn_flags = PFN_DEV;
283 if (is_nd_pfn(dev)) {
284 addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter,
286 pfn_sb = nd_pfn->pfn_sb;
287 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
288 pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res);
289 pmem->pfn_flags |= PFN_MAP;
290 res = &pfn_res; /* for badblocks populate */
291 res->start += pmem->data_offset;
292 } else if (pmem_should_map_pages(dev)) {
293 addr = devm_memremap_pages(dev, &nsio->res,
294 &q->q_usage_counter, NULL);
295 pmem->pfn_flags |= PFN_MAP;
297 addr = devm_memremap(dev, pmem->phys_addr,
298 pmem->size, ARCH_MEMREMAP_PMEM);
301 * At release time the queue must be dead before
302 * devm_memremap_pages is unwound
304 if (devm_add_action_or_reset(dev, pmem_release_queue, q))
308 return PTR_ERR(addr);
309 pmem->virt_addr = addr;
311 blk_queue_write_cache(q, true, true);
312 blk_queue_make_request(q, pmem_make_request);
313 blk_queue_physical_block_size(q, PAGE_SIZE);
314 blk_queue_max_hw_sectors(q, UINT_MAX);
315 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
316 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
317 queue_flag_set_unlocked(QUEUE_FLAG_DAX, q);
320 disk = alloc_disk_node(0, nid);
324 disk->fops = &pmem_fops;
326 disk->flags = GENHD_FL_EXT_DEVT;
327 nvdimm_namespace_disk_name(ndns, disk->disk_name);
328 set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
330 if (devm_init_badblocks(dev, &pmem->bb))
332 nvdimm_badblocks_populate(nd_region, &pmem->bb, res);
333 disk->bb = &pmem->bb;
334 device_add_disk(dev, disk);
336 if (devm_add_action_or_reset(dev, pmem_release_disk, disk))
339 revalidate_disk(disk);
344 static int nd_pmem_probe(struct device *dev)
346 struct nd_namespace_common *ndns;
348 ndns = nvdimm_namespace_common_probe(dev);
350 return PTR_ERR(ndns);
352 if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
356 return nvdimm_namespace_attach_btt(ndns);
359 return pmem_attach_disk(dev, ndns);
361 /* if we find a valid info-block we'll come back as that personality */
362 if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
363 || nd_dax_probe(dev, ndns) == 0)
366 /* ...otherwise we're just a raw pmem device */
367 return pmem_attach_disk(dev, ndns);
370 static int nd_pmem_remove(struct device *dev)
373 nvdimm_namespace_detach_btt(to_nd_btt(dev));
374 nvdimm_flush(to_nd_region(dev->parent));
379 static void nd_pmem_shutdown(struct device *dev)
381 nvdimm_flush(to_nd_region(dev->parent));
384 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
386 struct pmem_device *pmem = dev_get_drvdata(dev);
387 struct nd_region *nd_region = to_region(pmem);
388 resource_size_t offset = 0, end_trunc = 0;
389 struct nd_namespace_common *ndns;
390 struct nd_namespace_io *nsio;
393 if (event != NVDIMM_REVALIDATE_POISON)
396 if (is_nd_btt(dev)) {
397 struct nd_btt *nd_btt = to_nd_btt(dev);
400 } else if (is_nd_pfn(dev)) {
401 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
402 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
405 offset = pmem->data_offset + __le32_to_cpu(pfn_sb->start_pad);
406 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
410 nsio = to_nd_namespace_io(&ndns->dev);
411 res.start = nsio->res.start + offset;
412 res.end = nsio->res.end - end_trunc;
413 nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);
416 MODULE_ALIAS("pmem");
417 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
418 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
419 static struct nd_device_driver nd_pmem_driver = {
420 .probe = nd_pmem_probe,
421 .remove = nd_pmem_remove,
422 .notify = nd_pmem_notify,
423 .shutdown = nd_pmem_shutdown,
427 .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
430 static int __init pmem_init(void)
432 return nd_driver_register(&nd_pmem_driver);
434 module_init(pmem_init);
436 static void pmem_exit(void)
438 driver_unregister(&nd_pmem_driver.drv);
440 module_exit(pmem_exit);
442 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
443 MODULE_LICENSE("GPL v2");