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 void 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);
66 invalidate_pmem(pmem->virt_addr + offset, len);
69 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
70 unsigned int len, unsigned int off, int op,
74 bool bad_pmem = false;
75 void *mem = kmap_atomic(page);
76 phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
77 void *pmem_addr = pmem->virt_addr + pmem_off;
79 if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
82 if (!op_is_write(op)) {
83 if (unlikely(bad_pmem))
86 rc = memcpy_from_pmem(mem + off, pmem_addr, len);
87 flush_dcache_page(page);
91 * Note that we write the data both before and after
92 * clearing poison. The write before clear poison
93 * handles situations where the latest written data is
94 * preserved and the clear poison operation simply marks
95 * the address range as valid without changing the data.
96 * In this case application software can assume that an
97 * interrupted write will either return the new good
100 * However, if pmem_clear_poison() leaves the data in an
101 * indeterminate state we need to perform the write
102 * after clear poison.
104 flush_dcache_page(page);
105 memcpy_to_pmem(pmem_addr, mem + off, len);
106 if (unlikely(bad_pmem)) {
107 pmem_clear_poison(pmem, pmem_off, len);
108 memcpy_to_pmem(pmem_addr, mem + off, len);
116 /* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */
118 #define REQ_FLUSH REQ_PREFLUSH
121 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
127 struct bvec_iter iter;
128 struct pmem_device *pmem = q->queuedata;
129 struct nd_region *nd_region = to_region(pmem);
131 if (bio->bi_rw & REQ_FLUSH)
132 nvdimm_flush(nd_region);
134 do_acct = nd_iostat_start(bio, &start);
135 bio_for_each_segment(bvec, bio, iter) {
136 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
137 bvec.bv_offset, bio_op(bio),
145 nd_iostat_end(bio, start);
147 if (bio->bi_rw & REQ_FUA)
148 nvdimm_flush(nd_region);
151 return BLK_QC_T_NONE;
154 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
155 struct page *page, int op)
157 struct pmem_device *pmem = bdev->bd_queue->queuedata;
160 rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, op, sector);
163 * The ->rw_page interface is subtle and tricky. The core
164 * retries on any error, so we can only invoke page_endio() in
165 * the successful completion case. Otherwise, we'll see crashes
166 * caused by double completion.
169 page_endio(page, op, 0);
174 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
175 __weak long pmem_direct_access(struct block_device *bdev, sector_t sector,
176 void **kaddr, pfn_t *pfn, long size)
178 struct pmem_device *pmem = bdev->bd_queue->queuedata;
179 resource_size_t offset = sector * 512 + pmem->data_offset;
181 if (unlikely(is_bad_pmem(&pmem->bb, sector, size)))
183 *kaddr = pmem->virt_addr + offset;
184 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
187 * If badblocks are present, limit known good range to the
190 if (unlikely(pmem->bb.count))
192 return pmem->size - pmem->pfn_pad - offset;
195 static const struct block_device_operations pmem_fops = {
196 .owner = THIS_MODULE,
197 .rw_page = pmem_rw_page,
198 .direct_access = pmem_direct_access,
199 .revalidate_disk = nvdimm_revalidate_disk,
202 static void pmem_release_queue(void *q)
204 blk_cleanup_queue(q);
207 static void pmem_release_disk(void *disk)
213 static int pmem_attach_disk(struct device *dev,
214 struct nd_namespace_common *ndns)
216 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
217 struct nd_region *nd_region = to_nd_region(dev->parent);
218 struct vmem_altmap __altmap, *altmap = NULL;
219 struct resource *res = &nsio->res;
220 struct nd_pfn *nd_pfn = NULL;
221 int nid = dev_to_node(dev);
222 struct nd_pfn_sb *pfn_sb;
223 struct pmem_device *pmem;
224 struct resource pfn_res;
225 struct request_queue *q;
226 struct gendisk *disk;
229 /* while nsio_rw_bytes is active, parse a pfn info block if present */
230 if (is_nd_pfn(dev)) {
231 nd_pfn = to_nd_pfn(dev);
232 altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap);
234 return PTR_ERR(altmap);
237 /* we're attaching a block device, disable raw namespace access */
238 devm_nsio_disable(dev, nsio);
240 pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
244 dev_set_drvdata(dev, pmem);
245 pmem->phys_addr = res->start;
246 pmem->size = resource_size(res);
247 if (nvdimm_has_flush(nd_region) < 0)
248 dev_warn(dev, "unable to guarantee persistence of writes\n");
250 if (!devm_request_mem_region(dev, res->start, resource_size(res),
252 dev_warn(dev, "could not reserve region %pR\n", res);
256 q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
260 pmem->pfn_flags = PFN_DEV;
261 if (is_nd_pfn(dev)) {
262 addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter,
264 pfn_sb = nd_pfn->pfn_sb;
265 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
266 pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res);
267 pmem->pfn_flags |= PFN_MAP;
268 res = &pfn_res; /* for badblocks populate */
269 res->start += pmem->data_offset;
270 } else if (pmem_should_map_pages(dev)) {
271 addr = devm_memremap_pages(dev, &nsio->res,
272 &q->q_usage_counter, NULL);
273 pmem->pfn_flags |= PFN_MAP;
275 addr = devm_memremap(dev, pmem->phys_addr,
276 pmem->size, ARCH_MEMREMAP_PMEM);
279 * At release time the queue must be dead before
280 * devm_memremap_pages is unwound
282 if (devm_add_action_or_reset(dev, pmem_release_queue, q))
286 return PTR_ERR(addr);
287 pmem->virt_addr = addr;
289 blk_queue_write_cache(q, true, true);
290 blk_queue_make_request(q, pmem_make_request);
291 blk_queue_physical_block_size(q, PAGE_SIZE);
292 blk_queue_max_hw_sectors(q, UINT_MAX);
293 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
294 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
295 queue_flag_set_unlocked(QUEUE_FLAG_DAX, q);
298 disk = alloc_disk_node(0, nid);
302 disk->fops = &pmem_fops;
304 disk->flags = GENHD_FL_EXT_DEVT;
305 nvdimm_namespace_disk_name(ndns, disk->disk_name);
306 set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
308 if (devm_init_badblocks(dev, &pmem->bb))
310 nvdimm_badblocks_populate(nd_region, &pmem->bb, res);
311 disk->bb = &pmem->bb;
312 device_add_disk(dev, disk);
314 if (devm_add_action_or_reset(dev, pmem_release_disk, disk))
317 revalidate_disk(disk);
322 static int nd_pmem_probe(struct device *dev)
324 struct nd_namespace_common *ndns;
326 ndns = nvdimm_namespace_common_probe(dev);
328 return PTR_ERR(ndns);
330 if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
334 return nvdimm_namespace_attach_btt(ndns);
337 return pmem_attach_disk(dev, ndns);
339 /* if we find a valid info-block we'll come back as that personality */
340 if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
341 || nd_dax_probe(dev, ndns) == 0)
344 /* ...otherwise we're just a raw pmem device */
345 return pmem_attach_disk(dev, ndns);
348 static int nd_pmem_remove(struct device *dev)
351 nvdimm_namespace_detach_btt(to_nd_btt(dev));
352 nvdimm_flush(to_nd_region(dev->parent));
357 static void nd_pmem_shutdown(struct device *dev)
359 nvdimm_flush(to_nd_region(dev->parent));
362 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
364 struct pmem_device *pmem = dev_get_drvdata(dev);
365 struct nd_region *nd_region = to_region(pmem);
366 resource_size_t offset = 0, end_trunc = 0;
367 struct nd_namespace_common *ndns;
368 struct nd_namespace_io *nsio;
371 if (event != NVDIMM_REVALIDATE_POISON)
374 if (is_nd_btt(dev)) {
375 struct nd_btt *nd_btt = to_nd_btt(dev);
378 } else if (is_nd_pfn(dev)) {
379 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
380 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
383 offset = pmem->data_offset + __le32_to_cpu(pfn_sb->start_pad);
384 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
388 nsio = to_nd_namespace_io(&ndns->dev);
389 res.start = nsio->res.start + offset;
390 res.end = nsio->res.end - end_trunc;
391 nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);
394 MODULE_ALIAS("pmem");
395 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
396 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
397 static struct nd_device_driver nd_pmem_driver = {
398 .probe = nd_pmem_probe,
399 .remove = nd_pmem_remove,
400 .notify = nd_pmem_notify,
401 .shutdown = nd_pmem_shutdown,
405 .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
408 static int __init pmem_init(void)
410 return nd_driver_register(&nd_pmem_driver);
412 module_init(pmem_init);
414 static void pmem_exit(void)
416 driver_unregister(&nd_pmem_driver.drv);
418 module_exit(pmem_exit);
420 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
421 MODULE_LICENSE("GPL v2");