blob: 0e39e3d1846fe07d7e77bdb2b25439d627b50ffb [file] [log] [blame]
/*
* Persistent Memory Driver
*
* Copyright (c) 2014-2015, Intel Corporation.
* Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
* Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <asm/cacheflush.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/set_memory.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/badblocks.h>
#include <linux/memremap.h>
#include <linux/vmalloc.h>
#include <linux/blk-mq.h>
#include <linux/pfn_t.h>
#include <linux/slab.h>
#include <linux/uio.h>
#include <linux/dax.h>
#include <linux/nd.h>
#include <linux/backing-dev.h>
#include "pmem.h"
#include "pfn.h"
#include "nd.h"
#include "nd-core.h"
static struct device *to_dev(struct pmem_device *pmem)
{
/*
* nvdimm bus services need a 'dev' parameter, and we record the device
* at init in bb.dev.
*/
return pmem->bb.dev;
}
static struct nd_region *to_region(struct pmem_device *pmem)
{
return to_nd_region(to_dev(pmem)->parent);
}
static void hwpoison_clear(struct pmem_device *pmem,
phys_addr_t phys, unsigned int len)
{
unsigned long pfn_start, pfn_end, pfn;
/* only pmem in the linear map supports HWPoison */
if (is_vmalloc_addr(pmem->virt_addr))
return;
pfn_start = PHYS_PFN(phys);
pfn_end = pfn_start + PHYS_PFN(len);
for (pfn = pfn_start; pfn < pfn_end; pfn++) {
struct page *page = pfn_to_page(pfn);
/*
* Note, no need to hold a get_dev_pagemap() reference
* here since we're in the driver I/O path and
* outstanding I/O requests pin the dev_pagemap.
*/
if (test_and_clear_pmem_poison(page))
clear_mce_nospec(pfn);
}
}
static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
phys_addr_t offset, unsigned int len)
{
struct device *dev = to_dev(pmem);
sector_t sector;
long cleared;
blk_status_t rc = BLK_STS_OK;
sector = (offset - pmem->data_offset) / 512;
cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
if (cleared < len)
rc = BLK_STS_IOERR;
if (cleared > 0 && cleared / 512) {
hwpoison_clear(pmem, pmem->phys_addr + offset, cleared);
cleared /= 512;
dev_dbg(dev, "%#llx clear %ld sector%s\n",
(unsigned long long) sector, cleared,
cleared > 1 ? "s" : "");
badblocks_clear(&pmem->bb, sector, cleared);
if (pmem->bb_state)
sysfs_notify_dirent(pmem->bb_state);
}
arch_invalidate_pmem(pmem->virt_addr + offset, len);
return rc;
}
static void write_pmem(void *pmem_addr, struct page *page,
unsigned int off, unsigned int len)
{
unsigned int chunk;
void *mem;
while (len) {
mem = kmap_atomic(page);
chunk = min_t(unsigned int, len, PAGE_SIZE);
memcpy_flushcache(pmem_addr, mem + off, chunk);
kunmap_atomic(mem);
len -= chunk;
off = 0;
page++;
pmem_addr += PAGE_SIZE;
}
}
static blk_status_t read_pmem(struct page *page, unsigned int off,
void *pmem_addr, unsigned int len)
{
unsigned int chunk;
unsigned long rem;
void *mem;
while (len) {
mem = kmap_atomic(page);
chunk = min_t(unsigned int, len, PAGE_SIZE);
rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
kunmap_atomic(mem);
if (rem)
return BLK_STS_IOERR;
len -= chunk;
off = 0;
page++;
pmem_addr += PAGE_SIZE;
}
return BLK_STS_OK;
}
static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
unsigned int len, unsigned int off, unsigned int op,
sector_t sector)
{
blk_status_t rc = BLK_STS_OK;
bool bad_pmem = false;
phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
void *pmem_addr = pmem->virt_addr + pmem_off;
if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
bad_pmem = true;
if (!op_is_write(op)) {
if (unlikely(bad_pmem))
rc = BLK_STS_IOERR;
else {
rc = read_pmem(page, off, pmem_addr, len);
flush_dcache_page(page);
}
} else {
/*
* Note that we write the data both before and after
* clearing poison. The write before clear poison
* handles situations where the latest written data is
* preserved and the clear poison operation simply marks
* the address range as valid without changing the data.
* In this case application software can assume that an
* interrupted write will either return the new good
* data or an error.
*
* However, if pmem_clear_poison() leaves the data in an
* indeterminate state we need to perform the write
* after clear poison.
*/
flush_dcache_page(page);
write_pmem(pmem_addr, page, off, len);
if (unlikely(bad_pmem)) {
rc = pmem_clear_poison(pmem, pmem_off, len);
write_pmem(pmem_addr, page, off, len);
}
}
return rc;
}
static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
{
blk_status_t rc = 0;
bool do_acct;
unsigned long start;
struct bio_vec bvec;
struct bvec_iter iter;
struct pmem_device *pmem = q->queuedata;
struct nd_region *nd_region = to_region(pmem);
if (bio->bi_opf & REQ_PREFLUSH)
nvdimm_flush(nd_region);
do_acct = nd_iostat_start(bio, &start);
bio_for_each_segment(bvec, bio, iter) {
rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
bvec.bv_offset, bio_op(bio), iter.bi_sector);
if (rc) {
bio->bi_status = rc;
break;
}
}
if (do_acct)
nd_iostat_end(bio, start);
if (bio->bi_opf & REQ_FUA)
nvdimm_flush(nd_region);
bio_endio(bio);
return BLK_QC_T_NONE;
}
static int pmem_rw_page(struct block_device *bdev, sector_t sector,
struct page *page, unsigned int op)
{
struct pmem_device *pmem = bdev->bd_queue->queuedata;
blk_status_t rc;
rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
0, op, sector);
/*
* The ->rw_page interface is subtle and tricky. The core
* retries on any error, so we can only invoke page_endio() in
* the successful completion case. Otherwise, we'll see crashes
* caused by double completion.
*/
if (rc == 0)
page_endio(page, op_is_write(op), 0);
return blk_status_to_errno(rc);
}
/* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
__weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
long nr_pages, void **kaddr, pfn_t *pfn)
{
resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
PFN_PHYS(nr_pages))))
return -EIO;
if (kaddr)
*kaddr = pmem->virt_addr + offset;
if (pfn)
*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
/*
* If badblocks are present, limit known good range to the
* requested range.
*/
if (unlikely(pmem->bb.count))
return nr_pages;
return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
}
static const struct block_device_operations pmem_fops = {
.owner = THIS_MODULE,
.rw_page = pmem_rw_page,
.revalidate_disk = nvdimm_revalidate_disk,
};
static long pmem_dax_direct_access(struct dax_device *dax_dev,
pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
{
struct pmem_device *pmem = dax_get_private(dax_dev);
return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
}
static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
return copy_from_iter_flushcache(addr, bytes, i);
}
static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
return copy_to_iter_mcsafe(addr, bytes, i);
}
static const struct dax_operations pmem_dax_ops = {
.direct_access = pmem_dax_direct_access,
.copy_from_iter = pmem_copy_from_iter,
.copy_to_iter = pmem_copy_to_iter,
};
static const struct attribute_group *pmem_attribute_groups[] = {
&dax_attribute_group,
NULL,
};
static void pmem_release_queue(void *q)
{
blk_cleanup_queue(q);
}
static void pmem_freeze_queue(void *q)
{
blk_freeze_queue_start(q);
}
static void pmem_release_disk(void *__pmem)
{
struct pmem_device *pmem = __pmem;
kill_dax(pmem->dax_dev);
put_dax(pmem->dax_dev);
del_gendisk(pmem->disk);
put_disk(pmem->disk);
}
static void pmem_release_pgmap_ops(void *__pgmap)
{
dev_pagemap_put_ops();
}
static void fsdax_pagefree(struct page *page, void *data)
{
wake_up_var(&page->_refcount);
}
static int setup_pagemap_fsdax(struct device *dev, struct dev_pagemap *pgmap)
{
dev_pagemap_get_ops();
if (devm_add_action_or_reset(dev, pmem_release_pgmap_ops, pgmap))
return -ENOMEM;
pgmap->type = MEMORY_DEVICE_FS_DAX;
pgmap->page_free = fsdax_pagefree;
return 0;
}
static int pmem_attach_disk(struct device *dev,
struct nd_namespace_common *ndns)
{
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
struct nd_region *nd_region = to_nd_region(dev->parent);
int nid = dev_to_node(dev), fua;
struct resource *res = &nsio->res;
struct resource bb_res;
struct nd_pfn *nd_pfn = NULL;
struct dax_device *dax_dev;
struct nd_pfn_sb *pfn_sb;
struct pmem_device *pmem;
struct request_queue *q;
struct device *gendev;
struct gendisk *disk;
void *addr;
int rc;
pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
if (!pmem)
return -ENOMEM;
/* while nsio_rw_bytes is active, parse a pfn info block if present */
if (is_nd_pfn(dev)) {
nd_pfn = to_nd_pfn(dev);
rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
if (rc)
return rc;
}
/* we're attaching a block device, disable raw namespace access */
devm_nsio_disable(dev, nsio);
dev_set_drvdata(dev, pmem);
pmem->phys_addr = res->start;
pmem->size = resource_size(res);
fua = nvdimm_has_flush(nd_region);
if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
dev_warn(dev, "unable to guarantee persistence of writes\n");
fua = 0;
}
if (!devm_request_mem_region(dev, res->start, resource_size(res),
dev_name(&ndns->dev))) {
dev_warn(dev, "could not reserve region %pR\n", res);
return -EBUSY;
}
q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev), NULL);
if (!q)
return -ENOMEM;
if (devm_add_action_or_reset(dev, pmem_release_queue, q))
return -ENOMEM;
pmem->pfn_flags = PFN_DEV;
pmem->pgmap.ref = &q->q_usage_counter;
if (is_nd_pfn(dev)) {
if (setup_pagemap_fsdax(dev, &pmem->pgmap))
return -ENOMEM;
addr = devm_memremap_pages(dev, &pmem->pgmap);
pfn_sb = nd_pfn->pfn_sb;
pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
pmem->pfn_pad = resource_size(res) -
resource_size(&pmem->pgmap.res);
pmem->pfn_flags |= PFN_MAP;
memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
bb_res.start += pmem->data_offset;
} else if (pmem_should_map_pages(dev)) {
memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
pmem->pgmap.altmap_valid = false;
if (setup_pagemap_fsdax(dev, &pmem->pgmap))
return -ENOMEM;
addr = devm_memremap_pages(dev, &pmem->pgmap);
pmem->pfn_flags |= PFN_MAP;
memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
} else {
addr = devm_memremap(dev, pmem->phys_addr,
pmem->size, ARCH_MEMREMAP_PMEM);
memcpy(&bb_res, &nsio->res, sizeof(bb_res));
}
/*
* At release time the queue must be frozen before
* devm_memremap_pages is unwound
*/
if (devm_add_action_or_reset(dev, pmem_freeze_queue, q))
return -ENOMEM;
if (IS_ERR(addr))
return PTR_ERR(addr);
pmem->virt_addr = addr;
blk_queue_write_cache(q, true, fua);
blk_queue_make_request(q, pmem_make_request);
blk_queue_physical_block_size(q, PAGE_SIZE);
blk_queue_logical_block_size(q, pmem_sector_size(ndns));
blk_queue_max_hw_sectors(q, UINT_MAX);
blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
if (pmem->pfn_flags & PFN_MAP)
blk_queue_flag_set(QUEUE_FLAG_DAX, q);
q->queuedata = pmem;
disk = alloc_disk_node(0, nid);
if (!disk)
return -ENOMEM;
pmem->disk = disk;
disk->fops = &pmem_fops;
disk->queue = q;
disk->flags = GENHD_FL_EXT_DEVT;
disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
nvdimm_namespace_disk_name(ndns, disk->disk_name);
set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
/ 512);
if (devm_init_badblocks(dev, &pmem->bb))
return -ENOMEM;
nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
disk->bb = &pmem->bb;
dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
if (!dax_dev) {
put_disk(disk);
return -ENOMEM;
}
dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
pmem->dax_dev = dax_dev;
gendev = disk_to_dev(disk);
gendev->groups = pmem_attribute_groups;
device_add_disk(dev, disk, NULL);
if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
return -ENOMEM;
revalidate_disk(disk);
pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
"badblocks");
if (!pmem->bb_state)
dev_warn(dev, "'badblocks' notification disabled\n");
return 0;
}
static int nd_pmem_probe(struct device *dev)
{
struct nd_namespace_common *ndns;
ndns = nvdimm_namespace_common_probe(dev);
if (IS_ERR(ndns))
return PTR_ERR(ndns);
if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
return -ENXIO;
if (is_nd_btt(dev))
return nvdimm_namespace_attach_btt(ndns);
if (is_nd_pfn(dev))
return pmem_attach_disk(dev, ndns);
/* if we find a valid info-block we'll come back as that personality */
if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
|| nd_dax_probe(dev, ndns) == 0)
return -ENXIO;
/* ...otherwise we're just a raw pmem device */
return pmem_attach_disk(dev, ndns);
}
static int nd_pmem_remove(struct device *dev)
{
struct pmem_device *pmem = dev_get_drvdata(dev);
if (is_nd_btt(dev))
nvdimm_namespace_detach_btt(to_nd_btt(dev));
else {
/*
* Note, this assumes device_lock() context to not race
* nd_pmem_notify()
*/
sysfs_put(pmem->bb_state);
pmem->bb_state = NULL;
}
nvdimm_flush(to_nd_region(dev->parent));
return 0;
}
static void nd_pmem_shutdown(struct device *dev)
{
nvdimm_flush(to_nd_region(dev->parent));
}
static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
{
struct nd_region *nd_region;
resource_size_t offset = 0, end_trunc = 0;
struct nd_namespace_common *ndns;
struct nd_namespace_io *nsio;
struct resource res;
struct badblocks *bb;
struct kernfs_node *bb_state;
if (event != NVDIMM_REVALIDATE_POISON)
return;
if (is_nd_btt(dev)) {
struct nd_btt *nd_btt = to_nd_btt(dev);
ndns = nd_btt->ndns;
nd_region = to_nd_region(ndns->dev.parent);
nsio = to_nd_namespace_io(&ndns->dev);
bb = &nsio->bb;
bb_state = NULL;
} else {
struct pmem_device *pmem = dev_get_drvdata(dev);
nd_region = to_region(pmem);
bb = &pmem->bb;
bb_state = pmem->bb_state;
if (is_nd_pfn(dev)) {
struct nd_pfn *nd_pfn = to_nd_pfn(dev);
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
ndns = nd_pfn->ndns;
offset = pmem->data_offset +
__le32_to_cpu(pfn_sb->start_pad);
end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
} else {
ndns = to_ndns(dev);
}
nsio = to_nd_namespace_io(&ndns->dev);
}
res.start = nsio->res.start + offset;
res.end = nsio->res.end - end_trunc;
nvdimm_badblocks_populate(nd_region, bb, &res);
if (bb_state)
sysfs_notify_dirent(bb_state);
}
MODULE_ALIAS("pmem");
MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
static struct nd_device_driver nd_pmem_driver = {
.probe = nd_pmem_probe,
.remove = nd_pmem_remove,
.notify = nd_pmem_notify,
.shutdown = nd_pmem_shutdown,
.drv = {
.name = "nd_pmem",
},
.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
};
module_nd_driver(nd_pmem_driver);
MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
MODULE_LICENSE("GPL v2");