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/memory_hotplug.h>
25 #include <linux/moduleparam.h>
26 #include <linux/vmalloc.h>
27 #include <linux/slab.h>
28 #include <linux/pmem.h>
34 struct request_queue
*pmem_queue
;
35 struct gendisk
*pmem_disk
;
36 struct nd_namespace_common
*ndns
;
38 /* One contiguous memory region per device */
39 phys_addr_t phys_addr
;
40 /* when non-zero this device is hosting a 'pfn' instance */
41 phys_addr_t data_offset
;
42 void __pmem
*virt_addr
;
46 static int pmem_major
;
48 static void pmem_do_bvec(struct pmem_device
*pmem
, struct page
*page
,
49 unsigned int len
, unsigned int off
, int rw
,
52 void *mem
= kmap_atomic(page
);
53 phys_addr_t pmem_off
= sector
* 512 + pmem
->data_offset
;
54 void __pmem
*pmem_addr
= pmem
->virt_addr
+ pmem_off
;
57 memcpy_from_pmem(mem
+ off
, pmem_addr
, len
);
58 flush_dcache_page(page
);
60 flush_dcache_page(page
);
61 memcpy_to_pmem(pmem_addr
, mem
+ off
, len
);
67 static void pmem_make_request(struct request_queue
*q
, struct bio
*bio
)
72 struct bvec_iter iter
;
73 struct block_device
*bdev
= bio
->bi_bdev
;
74 struct pmem_device
*pmem
= bdev
->bd_disk
->private_data
;
76 do_acct
= nd_iostat_start(bio
, &start
);
77 bio_for_each_segment(bvec
, bio
, iter
)
78 pmem_do_bvec(pmem
, bvec
.bv_page
, bvec
.bv_len
, bvec
.bv_offset
,
79 bio_data_dir(bio
), iter
.bi_sector
);
81 nd_iostat_end(bio
, start
);
83 if (bio_data_dir(bio
))
89 static int pmem_rw_page(struct block_device
*bdev
, sector_t sector
,
90 struct page
*page
, int rw
)
92 struct pmem_device
*pmem
= bdev
->bd_disk
->private_data
;
94 pmem_do_bvec(pmem
, page
, PAGE_CACHE_SIZE
, 0, rw
, sector
);
97 page_endio(page
, rw
& WRITE
, 0);
102 static long pmem_direct_access(struct block_device
*bdev
, sector_t sector
,
103 void __pmem
**kaddr
, unsigned long *pfn
)
105 struct pmem_device
*pmem
= bdev
->bd_disk
->private_data
;
106 resource_size_t offset
= sector
* 512 + pmem
->data_offset
;
107 resource_size_t size
;
109 if (pmem
->data_offset
) {
111 * Limit the direct_access() size to what is covered by
114 size
= (pmem
->size
- offset
) & ~ND_PFN_MASK
;
116 size
= pmem
->size
- offset
;
118 /* FIXME convert DAX to comprehend that this mapping has a lifetime */
119 *kaddr
= pmem
->virt_addr
+ offset
;
120 *pfn
= (pmem
->phys_addr
+ offset
) >> PAGE_SHIFT
;
125 static const struct block_device_operations pmem_fops
= {
126 .owner
= THIS_MODULE
,
127 .rw_page
= pmem_rw_page
,
128 .direct_access
= pmem_direct_access
,
129 .revalidate_disk
= nvdimm_revalidate_disk
,
132 static struct pmem_device
*pmem_alloc(struct device
*dev
,
133 struct resource
*res
, int id
)
135 struct pmem_device
*pmem
;
137 pmem
= devm_kzalloc(dev
, sizeof(*pmem
), GFP_KERNEL
);
139 return ERR_PTR(-ENOMEM
);
141 pmem
->phys_addr
= res
->start
;
142 pmem
->size
= resource_size(res
);
143 if (!arch_has_wmb_pmem())
144 dev_warn(dev
, "unable to guarantee persistence of writes\n");
146 if (!devm_request_mem_region(dev
, pmem
->phys_addr
, pmem
->size
,
148 dev_warn(dev
, "could not reserve region [0x%pa:0x%zx]\n",
149 &pmem
->phys_addr
, pmem
->size
);
150 return ERR_PTR(-EBUSY
);
153 if (pmem_should_map_pages(dev
)) {
154 void *addr
= devm_memremap_pages(dev
, res
);
158 pmem
->virt_addr
= (void __pmem
*) addr
;
160 pmem
->virt_addr
= memremap_pmem(dev
, pmem
->phys_addr
,
162 if (!pmem
->virt_addr
)
163 return ERR_PTR(-ENXIO
);
169 static void pmem_detach_disk(struct pmem_device
*pmem
)
171 if (!pmem
->pmem_disk
)
174 del_gendisk(pmem
->pmem_disk
);
175 put_disk(pmem
->pmem_disk
);
176 blk_cleanup_queue(pmem
->pmem_queue
);
179 static int pmem_attach_disk(struct device
*dev
,
180 struct nd_namespace_common
*ndns
, struct pmem_device
*pmem
)
182 struct gendisk
*disk
;
184 pmem
->pmem_queue
= blk_alloc_queue(GFP_KERNEL
);
185 if (!pmem
->pmem_queue
)
188 blk_queue_make_request(pmem
->pmem_queue
, pmem_make_request
);
189 blk_queue_physical_block_size(pmem
->pmem_queue
, PAGE_SIZE
);
190 blk_queue_max_hw_sectors(pmem
->pmem_queue
, UINT_MAX
);
191 blk_queue_bounce_limit(pmem
->pmem_queue
, BLK_BOUNCE_ANY
);
192 queue_flag_set_unlocked(QUEUE_FLAG_NONROT
, pmem
->pmem_queue
);
194 disk
= alloc_disk(0);
196 blk_cleanup_queue(pmem
->pmem_queue
);
200 disk
->major
= pmem_major
;
201 disk
->first_minor
= 0;
202 disk
->fops
= &pmem_fops
;
203 disk
->private_data
= pmem
;
204 disk
->queue
= pmem
->pmem_queue
;
205 disk
->flags
= GENHD_FL_EXT_DEVT
;
206 nvdimm_namespace_disk_name(ndns
, disk
->disk_name
);
207 disk
->driverfs_dev
= dev
;
208 set_capacity(disk
, (pmem
->size
- pmem
->data_offset
) / 512);
209 pmem
->pmem_disk
= disk
;
212 revalidate_disk(disk
);
217 static int pmem_rw_bytes(struct nd_namespace_common
*ndns
,
218 resource_size_t offset
, void *buf
, size_t size
, int rw
)
220 struct pmem_device
*pmem
= dev_get_drvdata(ndns
->claim
);
222 if (unlikely(offset
+ size
> pmem
->size
)) {
223 dev_WARN_ONCE(&ndns
->dev
, 1, "request out of range\n");
228 memcpy_from_pmem(buf
, pmem
->virt_addr
+ offset
, size
);
230 memcpy_to_pmem(pmem
->virt_addr
+ offset
, buf
, size
);
237 static int nd_pfn_init(struct nd_pfn
*nd_pfn
)
239 struct nd_pfn_sb
*pfn_sb
= kzalloc(sizeof(*pfn_sb
), GFP_KERNEL
);
240 struct pmem_device
*pmem
= dev_get_drvdata(&nd_pfn
->dev
);
241 struct nd_namespace_common
*ndns
= nd_pfn
->ndns
;
242 struct nd_region
*nd_region
;
251 nd_pfn
->pfn_sb
= pfn_sb
;
252 rc
= nd_pfn_validate(nd_pfn
);
253 if (rc
== 0 || rc
== -EBUSY
)
256 /* section alignment for simple hotplug */
257 if (nvdimm_namespace_capacity(ndns
) < ND_PFN_ALIGN
258 || pmem
->phys_addr
& ND_PFN_MASK
)
261 nd_region
= to_nd_region(nd_pfn
->dev
.parent
);
263 dev_info(&nd_pfn
->dev
,
264 "%s is read-only, unable to init metadata\n",
265 dev_name(&nd_region
->dev
));
269 memset(pfn_sb
, 0, sizeof(*pfn_sb
));
270 npfns
= (pmem
->size
- SZ_8K
) / SZ_4K
;
272 * Note, we use 64 here for the standard size of struct page,
273 * debugging options may cause it to be larger in which case the
274 * implementation will limit the pfns advertised through
275 * ->direct_access() to those that are included in the memmap.
277 if (nd_pfn
->mode
== PFN_MODE_PMEM
)
278 offset
= ALIGN(SZ_8K
+ 64 * npfns
, PMD_SIZE
);
279 else if (nd_pfn
->mode
== PFN_MODE_RAM
)
284 npfns
= (pmem
->size
- offset
) / SZ_4K
;
285 pfn_sb
->mode
= cpu_to_le32(nd_pfn
->mode
);
286 pfn_sb
->dataoff
= cpu_to_le64(offset
);
287 pfn_sb
->npfns
= cpu_to_le64(npfns
);
288 memcpy(pfn_sb
->signature
, PFN_SIG
, PFN_SIG_LEN
);
289 memcpy(pfn_sb
->uuid
, nd_pfn
->uuid
, 16);
290 pfn_sb
->version_major
= cpu_to_le16(1);
291 checksum
= nd_sb_checksum((struct nd_gen_sb
*) pfn_sb
);
292 pfn_sb
->checksum
= cpu_to_le64(checksum
);
294 rc
= nvdimm_write_bytes(ndns
, SZ_4K
, pfn_sb
, sizeof(*pfn_sb
));
300 nd_pfn
->pfn_sb
= NULL
;
305 static int nvdimm_namespace_detach_pfn(struct nd_namespace_common
*ndns
)
307 struct nd_pfn
*nd_pfn
= to_nd_pfn(ndns
->claim
);
308 struct pmem_device
*pmem
;
311 pmem
= dev_get_drvdata(&nd_pfn
->dev
);
312 pmem_detach_disk(pmem
);
314 /* release nd_pfn resources */
315 kfree(nd_pfn
->pfn_sb
);
316 nd_pfn
->pfn_sb
= NULL
;
321 static int nvdimm_namespace_attach_pfn(struct nd_namespace_common
*ndns
)
323 struct nd_namespace_io
*nsio
= to_nd_namespace_io(&ndns
->dev
);
324 struct nd_pfn
*nd_pfn
= to_nd_pfn(ndns
->claim
);
325 struct device
*dev
= &nd_pfn
->dev
;
326 struct vmem_altmap
*altmap
;
327 struct nd_region
*nd_region
;
328 struct nd_pfn_sb
*pfn_sb
;
329 struct pmem_device
*pmem
;
333 if (!nd_pfn
->uuid
|| !nd_pfn
->ndns
)
336 nd_region
= to_nd_region(dev
->parent
);
337 rc
= nd_pfn_init(nd_pfn
);
341 if (PAGE_SIZE
!= SZ_4K
) {
342 dev_err(dev
, "only supported on systems with 4K PAGE_SIZE\n");
345 if (nsio
->res
.start
& ND_PFN_MASK
) {
346 dev_err(dev
, "%s not memory hotplug section aligned\n",
347 dev_name(&ndns
->dev
));
351 pfn_sb
= nd_pfn
->pfn_sb
;
352 offset
= le64_to_cpu(pfn_sb
->dataoff
);
353 nd_pfn
->mode
= le32_to_cpu(nd_pfn
->pfn_sb
->mode
);
354 if (nd_pfn
->mode
== PFN_MODE_RAM
) {
357 nd_pfn
->npfns
= le64_to_cpu(pfn_sb
->npfns
);
364 /* establish pfn range for lookup, and switch to direct map */
365 pmem
= dev_get_drvdata(dev
);
366 memunmap_pmem(dev
, pmem
->virt_addr
);
367 pmem
->virt_addr
= (void __pmem
*)devm_memremap_pages(dev
, &nsio
->res
);
368 if (IS_ERR(pmem
->virt_addr
)) {
369 rc
= PTR_ERR(pmem
->virt_addr
);
373 /* attach pmem disk in "pfn-mode" */
374 pmem
->data_offset
= offset
;
375 rc
= pmem_attach_disk(dev
, ndns
, pmem
);
381 nvdimm_namespace_detach_pfn(ndns
);
385 static int nd_pmem_probe(struct device
*dev
)
387 struct nd_region
*nd_region
= to_nd_region(dev
->parent
);
388 struct nd_namespace_common
*ndns
;
389 struct nd_namespace_io
*nsio
;
390 struct pmem_device
*pmem
;
392 ndns
= nvdimm_namespace_common_probe(dev
);
394 return PTR_ERR(ndns
);
396 nsio
= to_nd_namespace_io(&ndns
->dev
);
397 pmem
= pmem_alloc(dev
, &nsio
->res
, nd_region
->id
);
399 return PTR_ERR(pmem
);
402 dev_set_drvdata(dev
, pmem
);
403 ndns
->rw_bytes
= pmem_rw_bytes
;
406 return nvdimm_namespace_attach_btt(ndns
);
409 return nvdimm_namespace_attach_pfn(ndns
);
411 if (nd_btt_probe(ndns
, pmem
) == 0) {
412 /* we'll come back as btt-pmem */
416 if (nd_pfn_probe(ndns
, pmem
) == 0) {
417 /* we'll come back as pfn-pmem */
421 return pmem_attach_disk(dev
, ndns
, pmem
);
424 static int nd_pmem_remove(struct device
*dev
)
426 struct pmem_device
*pmem
= dev_get_drvdata(dev
);
429 nvdimm_namespace_detach_btt(pmem
->ndns
);
430 else if (is_nd_pfn(dev
))
431 nvdimm_namespace_detach_pfn(pmem
->ndns
);
433 pmem_detach_disk(pmem
);
438 MODULE_ALIAS("pmem");
439 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO
);
440 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM
);
441 static struct nd_device_driver nd_pmem_driver
= {
442 .probe
= nd_pmem_probe
,
443 .remove
= nd_pmem_remove
,
447 .type
= ND_DRIVER_NAMESPACE_IO
| ND_DRIVER_NAMESPACE_PMEM
,
450 static int __init
pmem_init(void)
454 pmem_major
= register_blkdev(0, "pmem");
458 error
= nd_driver_register(&nd_pmem_driver
);
460 unregister_blkdev(pmem_major
, "pmem");
466 module_init(pmem_init
);
468 static void pmem_exit(void)
470 driver_unregister(&nd_pmem_driver
.drv
);
471 unregister_blkdev(pmem_major
, "pmem");
473 module_exit(pmem_exit
);
475 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
476 MODULE_LICENSE("GPL v2");