blob: f798899338eddb6955c06f5b44c26c405dffdade [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/module.h>
#include <linux/moduleparam.h>
#include <linux/badblocks.h>
#include <linux/memremap.h>
#include <linux/vmalloc.h>
#include <linux/pfn_t.h>
#include <linux/slab.h>
#include <linux/pmem.h>
#include <linux/nd.h>
#include "pfn.h"
#include "nd.h"
struct pmem_device {
struct request_queue *pmem_queue;
struct gendisk *pmem_disk;
struct nd_namespace_common *ndns;
/* One contiguous memory region per device */
phys_addr_t phys_addr;
/* when non-zero this device is hosting a 'pfn' instance */
phys_addr_t data_offset;
u64 pfn_flags;
void __pmem *virt_addr;
/* immutable base size of the namespace */
size_t size;
/* trim size when namespace capacity has been section aligned */
u32 pfn_pad;
struct badblocks bb;
};
static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len)
{
if (bb->count) {
sector_t first_bad;
int num_bad;
return !!badblocks_check(bb, sector, len / 512, &first_bad,
&num_bad);
}
return false;
}
static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
unsigned int len)
{
struct device *dev = disk_to_dev(pmem->pmem_disk);
sector_t sector;
long cleared;
sector = (offset - pmem->data_offset) / 512;
cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
if (cleared > 0 && cleared / 512) {
dev_dbg(dev, "%s: %llx clear %ld sector%s\n",
__func__, (unsigned long long) sector,
cleared / 512, cleared / 512 > 1 ? "s" : "");
badblocks_clear(&pmem->bb, sector, cleared / 512);
}
invalidate_pmem(pmem->virt_addr + offset, len);
}
static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
unsigned int len, unsigned int off, int rw,
sector_t sector)
{
int rc = 0;
bool bad_pmem = false;
void *mem = kmap_atomic(page);
phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
bad_pmem = true;
if (rw == READ) {
if (unlikely(bad_pmem))
rc = -EIO;
else {
rc = memcpy_from_pmem(mem + 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);
memcpy_to_pmem(pmem_addr, mem + off, len);
if (unlikely(bad_pmem)) {
pmem_clear_poison(pmem, pmem_off, len);
memcpy_to_pmem(pmem_addr, mem + off, len);
}
}
kunmap_atomic(mem);
return rc;
}
static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
{
int rc = 0;
bool do_acct;
unsigned long start;
struct bio_vec bvec;
struct bvec_iter iter;
struct block_device *bdev = bio->bi_bdev;
struct pmem_device *pmem = bdev->bd_disk->private_data;
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_data_dir(bio),
iter.bi_sector);
if (rc) {
bio->bi_error = rc;
break;
}
}
if (do_acct)
nd_iostat_end(bio, start);
if (bio_data_dir(bio))
wmb_pmem();
bio_endio(bio);
return BLK_QC_T_NONE;
}
static int pmem_rw_page(struct block_device *bdev, sector_t sector,
struct page *page, int rw)
{
struct pmem_device *pmem = bdev->bd_disk->private_data;
int rc;
rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector);
if (rw & WRITE)
wmb_pmem();
/*
* 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, rw & WRITE, 0);
return rc;
}
static long pmem_direct_access(struct block_device *bdev, sector_t sector,
void __pmem **kaddr, pfn_t *pfn)
{
struct pmem_device *pmem = bdev->bd_disk->private_data;
resource_size_t offset = sector * 512 + pmem->data_offset;
*kaddr = pmem->virt_addr + offset;
*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
return pmem->size - pmem->pfn_pad - offset;
}
static const struct block_device_operations pmem_fops = {
.owner = THIS_MODULE,
.rw_page = pmem_rw_page,
.direct_access = pmem_direct_access,
.revalidate_disk = nvdimm_revalidate_disk,
};
static struct pmem_device *pmem_alloc(struct device *dev,
struct resource *res, int id)
{
struct pmem_device *pmem;
struct request_queue *q;
pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
if (!pmem)
return ERR_PTR(-ENOMEM);
pmem->phys_addr = res->start;
pmem->size = resource_size(res);
if (!arch_has_wmb_pmem())
dev_warn(dev, "unable to guarantee persistence of writes\n");
if (!devm_request_mem_region(dev, pmem->phys_addr, pmem->size,
dev_name(dev))) {
dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
&pmem->phys_addr, pmem->size);
return ERR_PTR(-EBUSY);
}
q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
if (!q)
return ERR_PTR(-ENOMEM);
pmem->pfn_flags = PFN_DEV;
if (pmem_should_map_pages(dev)) {
pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, res,
&q->q_usage_counter, NULL);
pmem->pfn_flags |= PFN_MAP;
} else
pmem->virt_addr = (void __pmem *) devm_memremap(dev,
pmem->phys_addr, pmem->size,
ARCH_MEMREMAP_PMEM);
if (IS_ERR(pmem->virt_addr)) {
blk_cleanup_queue(q);
return (void __force *) pmem->virt_addr;
}
pmem->pmem_queue = q;
return pmem;
}
static void pmem_detach_disk(struct pmem_device *pmem)
{
if (!pmem->pmem_disk)
return;
del_gendisk(pmem->pmem_disk);
put_disk(pmem->pmem_disk);
blk_cleanup_queue(pmem->pmem_queue);
}
static int pmem_attach_disk(struct device *dev,
struct nd_namespace_common *ndns, struct pmem_device *pmem)
{
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
int nid = dev_to_node(dev);
struct resource bb_res;
struct gendisk *disk;
blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE);
blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX);
blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue);
disk = alloc_disk_node(0, nid);
if (!disk) {
blk_cleanup_queue(pmem->pmem_queue);
return -ENOMEM;
}
disk->fops = &pmem_fops;
disk->private_data = pmem;
disk->queue = pmem->pmem_queue;
disk->flags = GENHD_FL_EXT_DEVT;
nvdimm_namespace_disk_name(ndns, disk->disk_name);
disk->driverfs_dev = dev;
set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
/ 512);
pmem->pmem_disk = disk;
devm_exit_badblocks(dev, &pmem->bb);
if (devm_init_badblocks(dev, &pmem->bb))
return -ENOMEM;
bb_res.start = nsio->res.start + pmem->data_offset;
bb_res.end = nsio->res.end;
if (is_nd_pfn(dev)) {
struct nd_pfn *nd_pfn = to_nd_pfn(dev);
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
bb_res.start += __le32_to_cpu(pfn_sb->start_pad);
bb_res.end -= __le32_to_cpu(pfn_sb->end_trunc);
}
nvdimm_badblocks_populate(to_nd_region(dev->parent), &pmem->bb,
&bb_res);
disk->bb = &pmem->bb;
add_disk(disk);
revalidate_disk(disk);
return 0;
}
static int pmem_rw_bytes(struct nd_namespace_common *ndns,
resource_size_t offset, void *buf, size_t size, int rw)
{
struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
if (unlikely(offset + size > pmem->size)) {
dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
return -EFAULT;
}
if (rw == READ) {
unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
if (unlikely(is_bad_pmem(&pmem->bb, offset / 512, sz_align)))
return -EIO;
return memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
} else {
memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
wmb_pmem();
}
return 0;
}
static int nd_pfn_init(struct nd_pfn *nd_pfn)
{
struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
struct nd_namespace_common *ndns = nd_pfn->ndns;
u32 start_pad = 0, end_trunc = 0;
resource_size_t start, size;
struct nd_namespace_io *nsio;
struct nd_region *nd_region;
unsigned long npfns;
phys_addr_t offset;
u64 checksum;
int rc;
if (!pfn_sb)
return -ENOMEM;
nd_pfn->pfn_sb = pfn_sb;
rc = nd_pfn_validate(nd_pfn);
if (rc == -ENODEV)
/* no info block, do init */;
else
return rc;
nd_region = to_nd_region(nd_pfn->dev.parent);
if (nd_region->ro) {
dev_info(&nd_pfn->dev,
"%s is read-only, unable to init metadata\n",
dev_name(&nd_region->dev));
goto err;
}
memset(pfn_sb, 0, sizeof(*pfn_sb));
/*
* Check if pmem collides with 'System RAM' when section aligned and
* trim it accordingly
*/
nsio = to_nd_namespace_io(&ndns->dev);
start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
size = resource_size(&nsio->res);
if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED) {
start = nsio->res.start;
start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
}
start = nsio->res.start;
size = PHYS_SECTION_ALIGN_UP(start + size) - start;
if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED) {
size = resource_size(&nsio->res);
end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
}
if (start_pad + end_trunc)
dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
dev_name(&ndns->dev), start_pad + end_trunc);
/*
* Note, we use 64 here for the standard size of struct page,
* debugging options may cause it to be larger in which case the
* implementation will limit the pfns advertised through
* ->direct_access() to those that are included in the memmap.
*/
start += start_pad;
npfns = (pmem->size - start_pad - end_trunc - SZ_8K) / SZ_4K;
if (nd_pfn->mode == PFN_MODE_PMEM)
offset = ALIGN(start + SZ_8K + 64 * npfns, nd_pfn->align)
- start;
else if (nd_pfn->mode == PFN_MODE_RAM)
offset = ALIGN(start + SZ_8K, nd_pfn->align) - start;
else
goto err;
if (offset + start_pad + end_trunc >= pmem->size) {
dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
dev_name(&ndns->dev));
goto err;
}
npfns = (pmem->size - offset - start_pad - end_trunc) / SZ_4K;
pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
pfn_sb->dataoff = cpu_to_le64(offset);
pfn_sb->npfns = cpu_to_le64(npfns);
memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
pfn_sb->version_major = cpu_to_le16(1);
pfn_sb->version_minor = cpu_to_le16(1);
pfn_sb->start_pad = cpu_to_le32(start_pad);
pfn_sb->end_trunc = cpu_to_le32(end_trunc);
checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
pfn_sb->checksum = cpu_to_le64(checksum);
rc = nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
if (rc)
goto err;
return 0;
err:
nd_pfn->pfn_sb = NULL;
kfree(pfn_sb);
return -ENXIO;
}
static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
{
struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
struct pmem_device *pmem;
/* free pmem disk */
pmem = dev_get_drvdata(&nd_pfn->dev);
pmem_detach_disk(pmem);
/* release nd_pfn resources */
kfree(nd_pfn->pfn_sb);
nd_pfn->pfn_sb = NULL;
return 0;
}
/*
* We hotplug memory at section granularity, pad the reserved area from
* the previous section base to the namespace base address.
*/
static unsigned long init_altmap_base(resource_size_t base)
{
unsigned long base_pfn = PHYS_PFN(base);
return PFN_SECTION_ALIGN_DOWN(base_pfn);
}
static unsigned long init_altmap_reserve(resource_size_t base)
{
unsigned long reserve = PHYS_PFN(SZ_8K);
unsigned long base_pfn = PHYS_PFN(base);
reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
return reserve;
}
static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
{
int rc;
struct resource res;
struct request_queue *q;
struct pmem_device *pmem;
struct vmem_altmap *altmap;
struct device *dev = &nd_pfn->dev;
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
struct nd_namespace_common *ndns = nd_pfn->ndns;
u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
resource_size_t base = nsio->res.start + start_pad;
struct vmem_altmap __altmap = {
.base_pfn = init_altmap_base(base),
.reserve = init_altmap_reserve(base),
};
pmem = dev_get_drvdata(dev);
pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
pmem->pfn_pad = start_pad + end_trunc;
nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
if (nd_pfn->mode == PFN_MODE_RAM) {
if (pmem->data_offset < SZ_8K)
return -EINVAL;
nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
altmap = NULL;
} else if (nd_pfn->mode == PFN_MODE_PMEM) {
nd_pfn->npfns = (pmem->size - pmem->pfn_pad - pmem->data_offset)
/ PAGE_SIZE;
if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
dev_info(&nd_pfn->dev,
"number of pfns truncated from %lld to %ld\n",
le64_to_cpu(nd_pfn->pfn_sb->npfns),
nd_pfn->npfns);
altmap = & __altmap;
altmap->free = PHYS_PFN(pmem->data_offset - SZ_8K);
altmap->alloc = 0;
} else {
rc = -ENXIO;
goto err;
}
/* establish pfn range for lookup, and switch to direct map */
q = pmem->pmem_queue;
memcpy(&res, &nsio->res, sizeof(res));
res.start += start_pad;
res.end -= end_trunc;
devm_memunmap(dev, (void __force *) pmem->virt_addr);
pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,
&q->q_usage_counter, altmap);
pmem->pfn_flags |= PFN_MAP;
if (IS_ERR(pmem->virt_addr)) {
rc = PTR_ERR(pmem->virt_addr);
goto err;
}
/* attach pmem disk in "pfn-mode" */
rc = pmem_attach_disk(dev, ndns, pmem);
if (rc)
goto err;
return rc;
err:
nvdimm_namespace_detach_pfn(ndns);
return rc;
}
static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
{
struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
int rc;
if (!nd_pfn->uuid || !nd_pfn->ndns)
return -ENODEV;
rc = nd_pfn_init(nd_pfn);
if (rc)
return rc;
/* we need a valid pfn_sb before we can init a vmem_altmap */
return __nvdimm_namespace_attach_pfn(nd_pfn);
}
static int nd_pmem_probe(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct nd_namespace_common *ndns;
struct nd_namespace_io *nsio;
struct pmem_device *pmem;
ndns = nvdimm_namespace_common_probe(dev);
if (IS_ERR(ndns))
return PTR_ERR(ndns);
nsio = to_nd_namespace_io(&ndns->dev);
pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
if (IS_ERR(pmem))
return PTR_ERR(pmem);
pmem->ndns = ndns;
dev_set_drvdata(dev, pmem);
ndns->rw_bytes = pmem_rw_bytes;
if (devm_init_badblocks(dev, &pmem->bb))
return -ENOMEM;
nvdimm_badblocks_populate(nd_region, &pmem->bb, &nsio->res);
if (is_nd_btt(dev)) {
/* btt allocates its own request_queue */
blk_cleanup_queue(pmem->pmem_queue);
pmem->pmem_queue = NULL;
return nvdimm_namespace_attach_btt(ndns);
}
if (is_nd_pfn(dev))
return nvdimm_namespace_attach_pfn(ndns);
if (nd_btt_probe(ndns, pmem) == 0 || nd_pfn_probe(ndns, pmem) == 0) {
/*
* We'll come back as either btt-pmem, or pfn-pmem, so
* drop the queue allocation for now.
*/
blk_cleanup_queue(pmem->pmem_queue);
return -ENXIO;
}
return pmem_attach_disk(dev, ndns, pmem);
}
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(pmem->ndns);
else if (is_nd_pfn(dev))
nvdimm_namespace_detach_pfn(pmem->ndns);
else
pmem_detach_disk(pmem);
return 0;
}
static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
{
struct pmem_device *pmem = dev_get_drvdata(dev);
struct nd_namespace_common *ndns = pmem->ndns;
struct nd_region *nd_region = to_nd_region(dev->parent);
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
struct resource res = {
.start = nsio->res.start + pmem->data_offset,
.end = nsio->res.end,
};
if (event != NVDIMM_REVALIDATE_POISON)
return;
if (is_nd_pfn(dev)) {
struct nd_pfn *nd_pfn = to_nd_pfn(dev);
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
res.start += __le32_to_cpu(pfn_sb->start_pad);
res.end -= __le32_to_cpu(pfn_sb->end_trunc);
}
nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);
}
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,
.drv = {
.name = "nd_pmem",
},
.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
};
static int __init pmem_init(void)
{
return nd_driver_register(&nd_pmem_driver);
}
module_init(pmem_init);
static void pmem_exit(void)
{
driver_unregister(&nd_pmem_driver.drv);
}
module_exit(pmem_exit);
MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
MODULE_LICENSE("GPL v2");