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/slab.h>
26 #include <linux/pmem.h>
31 struct request_queue
*pmem_queue
;
32 struct gendisk
*pmem_disk
;
34 /* One contiguous memory region per device */
35 phys_addr_t phys_addr
;
36 void __pmem
*virt_addr
;
40 static int pmem_major
;
42 static void pmem_do_bvec(struct pmem_device
*pmem
, struct page
*page
,
43 unsigned int len
, unsigned int off
, int rw
,
46 void *mem
= kmap_atomic(page
);
47 size_t pmem_off
= sector
<< 9;
48 void __pmem
*pmem_addr
= pmem
->virt_addr
+ pmem_off
;
51 memcpy_from_pmem(mem
+ off
, pmem_addr
, len
);
52 flush_dcache_page(page
);
54 flush_dcache_page(page
);
55 memcpy_to_pmem(pmem_addr
, mem
+ off
, len
);
61 static void pmem_make_request(struct request_queue
*q
, struct bio
*bio
)
66 struct bvec_iter iter
;
67 struct block_device
*bdev
= bio
->bi_bdev
;
68 struct pmem_device
*pmem
= bdev
->bd_disk
->private_data
;
70 do_acct
= nd_iostat_start(bio
, &start
);
71 bio_for_each_segment(bvec
, bio
, iter
)
72 pmem_do_bvec(pmem
, bvec
.bv_page
, bvec
.bv_len
, bvec
.bv_offset
,
73 bio_data_dir(bio
), iter
.bi_sector
);
75 nd_iostat_end(bio
, start
);
77 if (bio_data_dir(bio
))
83 static int pmem_rw_page(struct block_device
*bdev
, sector_t sector
,
84 struct page
*page
, int rw
)
86 struct pmem_device
*pmem
= bdev
->bd_disk
->private_data
;
88 pmem_do_bvec(pmem
, page
, PAGE_CACHE_SIZE
, 0, rw
, sector
);
89 page_endio(page
, rw
& WRITE
, 0);
94 static long pmem_direct_access(struct block_device
*bdev
, sector_t sector
,
95 void __pmem
**kaddr
, unsigned long *pfn
)
97 struct pmem_device
*pmem
= bdev
->bd_disk
->private_data
;
98 size_t offset
= sector
<< 9;
103 /* FIXME convert DAX to comprehend that this mapping has a lifetime */
104 *kaddr
= pmem
->virt_addr
+ offset
;
105 *pfn
= (pmem
->phys_addr
+ offset
) >> PAGE_SHIFT
;
107 return pmem
->size
- offset
;
110 static const struct block_device_operations pmem_fops
= {
111 .owner
= THIS_MODULE
,
112 .rw_page
= pmem_rw_page
,
113 .direct_access
= pmem_direct_access
,
114 .revalidate_disk
= nvdimm_revalidate_disk
,
117 static struct pmem_device
*pmem_alloc(struct device
*dev
,
118 struct resource
*res
, int id
)
120 struct pmem_device
*pmem
;
122 pmem
= devm_kzalloc(dev
, sizeof(*pmem
), GFP_KERNEL
);
124 return ERR_PTR(-ENOMEM
);
126 pmem
->phys_addr
= res
->start
;
127 pmem
->size
= resource_size(res
);
128 if (!arch_has_wmb_pmem())
129 dev_warn(dev
, "unable to guarantee persistence of writes\n");
131 if (!devm_request_mem_region(dev
, pmem
->phys_addr
, pmem
->size
,
133 dev_warn(dev
, "could not reserve region [0x%pa:0x%zx]\n",
134 &pmem
->phys_addr
, pmem
->size
);
135 return ERR_PTR(-EBUSY
);
138 pmem
->virt_addr
= memremap_pmem(dev
, pmem
->phys_addr
, pmem
->size
);
139 if (!pmem
->virt_addr
)
140 return ERR_PTR(-ENXIO
);
145 static void pmem_detach_disk(struct pmem_device
*pmem
)
147 del_gendisk(pmem
->pmem_disk
);
148 put_disk(pmem
->pmem_disk
);
149 blk_cleanup_queue(pmem
->pmem_queue
);
152 static int pmem_attach_disk(struct nd_namespace_common
*ndns
,
153 struct pmem_device
*pmem
)
155 struct gendisk
*disk
;
157 pmem
->pmem_queue
= blk_alloc_queue(GFP_KERNEL
);
158 if (!pmem
->pmem_queue
)
161 blk_queue_make_request(pmem
->pmem_queue
, pmem_make_request
);
162 blk_queue_physical_block_size(pmem
->pmem_queue
, PAGE_SIZE
);
163 blk_queue_max_hw_sectors(pmem
->pmem_queue
, UINT_MAX
);
164 blk_queue_bounce_limit(pmem
->pmem_queue
, BLK_BOUNCE_ANY
);
165 queue_flag_set_unlocked(QUEUE_FLAG_NONROT
, pmem
->pmem_queue
);
167 disk
= alloc_disk(0);
169 blk_cleanup_queue(pmem
->pmem_queue
);
173 disk
->major
= pmem_major
;
174 disk
->first_minor
= 0;
175 disk
->fops
= &pmem_fops
;
176 disk
->private_data
= pmem
;
177 disk
->queue
= pmem
->pmem_queue
;
178 disk
->flags
= GENHD_FL_EXT_DEVT
;
179 nvdimm_namespace_disk_name(ndns
, disk
->disk_name
);
180 disk
->driverfs_dev
= &ndns
->dev
;
181 set_capacity(disk
, pmem
->size
>> 9);
182 pmem
->pmem_disk
= disk
;
185 revalidate_disk(disk
);
190 static int pmem_rw_bytes(struct nd_namespace_common
*ndns
,
191 resource_size_t offset
, void *buf
, size_t size
, int rw
)
193 struct pmem_device
*pmem
= dev_get_drvdata(ndns
->claim
);
195 if (unlikely(offset
+ size
> pmem
->size
)) {
196 dev_WARN_ONCE(&ndns
->dev
, 1, "request out of range\n");
201 memcpy_from_pmem(buf
, pmem
->virt_addr
+ offset
, size
);
203 memcpy_to_pmem(pmem
->virt_addr
+ offset
, buf
, size
);
210 static int nd_pmem_probe(struct device
*dev
)
212 struct nd_region
*nd_region
= to_nd_region(dev
->parent
);
213 struct nd_namespace_common
*ndns
;
214 struct nd_namespace_io
*nsio
;
215 struct pmem_device
*pmem
;
217 ndns
= nvdimm_namespace_common_probe(dev
);
219 return PTR_ERR(ndns
);
221 nsio
= to_nd_namespace_io(&ndns
->dev
);
222 pmem
= pmem_alloc(dev
, &nsio
->res
, nd_region
->id
);
224 return PTR_ERR(pmem
);
226 dev_set_drvdata(dev
, pmem
);
227 ndns
->rw_bytes
= pmem_rw_bytes
;
230 return nvdimm_namespace_attach_btt(ndns
);
232 if (nd_btt_probe(ndns
, pmem
) == 0)
233 /* we'll come back as btt-pmem */
235 return pmem_attach_disk(ndns
, pmem
);
238 static int nd_pmem_remove(struct device
*dev
)
240 struct pmem_device
*pmem
= dev_get_drvdata(dev
);
243 nvdimm_namespace_detach_btt(to_nd_btt(dev
)->ndns
);
245 pmem_detach_disk(pmem
);
250 MODULE_ALIAS("pmem");
251 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO
);
252 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM
);
253 static struct nd_device_driver nd_pmem_driver
= {
254 .probe
= nd_pmem_probe
,
255 .remove
= nd_pmem_remove
,
259 .type
= ND_DRIVER_NAMESPACE_IO
| ND_DRIVER_NAMESPACE_PMEM
,
262 static int __init
pmem_init(void)
266 pmem_major
= register_blkdev(0, "pmem");
270 error
= nd_driver_register(&nd_pmem_driver
);
272 unregister_blkdev(pmem_major
, "pmem");
278 module_init(pmem_init
);
280 static void pmem_exit(void)
282 driver_unregister(&nd_pmem_driver
.drv
);
283 unregister_blkdev(pmem_major
, "pmem");
285 module_exit(pmem_exit
);
287 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
288 MODULE_LICENSE("GPL v2");