linux/drivers/nvdimm/pmem.c
Dan Williams 589e75d157 libnvdimm, pmem: fix size trim in pmem_direct_access()
This masking prevents access to the end of the device via dax_do_io(),
and is unnecessary as arch_add_memory() would have rejected an unaligned
allocation.

Cc: <stable@vger.kernel.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-11-12 09:55:23 -08:00

465 lines
11 KiB
C

/*
* 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/memory_hotplug.h>
#include <linux/moduleparam.h>
#include <linux/vmalloc.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;
void __pmem *virt_addr;
size_t size;
};
static int pmem_major;
static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
unsigned int len, unsigned int off, int rw,
sector_t sector)
{
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 (rw == READ) {
memcpy_from_pmem(mem + off, pmem_addr, len);
flush_dcache_page(page);
} else {
flush_dcache_page(page);
memcpy_to_pmem(pmem_addr, mem + off, len);
}
kunmap_atomic(mem);
}
static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
{
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)
pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset,
bio_data_dir(bio), iter.bi_sector);
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;
pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
if (rw & WRITE)
wmb_pmem();
page_endio(page, rw & WRITE, 0);
return 0;
}
static long pmem_direct_access(struct block_device *bdev, sector_t sector,
void __pmem **kaddr, unsigned long *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 = (pmem->phys_addr + offset) >> PAGE_SHIFT;
return pmem->size - 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;
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);
}
if (pmem_should_map_pages(dev))
pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, res);
else
pmem->virt_addr = (void __pmem *) devm_memremap(dev,
pmem->phys_addr, pmem->size,
ARCH_MEMREMAP_PMEM);
if (IS_ERR(pmem->virt_addr))
return (void __force *) pmem->virt_addr;
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)
{
int nid = dev_to_node(dev);
struct gendisk *disk;
pmem->pmem_queue = blk_alloc_queue_node(GFP_KERNEL, nid);
if (!pmem->pmem_queue)
return -ENOMEM;
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->major = pmem_major;
disk->first_minor = 0;
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->data_offset) / 512);
pmem->pmem_disk = disk;
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)
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;
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 == 0 || rc == -EBUSY)
return rc;
/* section alignment for simple hotplug */
if (nvdimm_namespace_capacity(ndns) < ND_PFN_ALIGN
|| pmem->phys_addr & ND_PFN_MASK)
return -ENODEV;
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));
npfns = (pmem->size - SZ_8K) / SZ_4K;
/*
* 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.
*/
if (nd_pfn->mode == PFN_MODE_PMEM)
offset = ALIGN(SZ_8K + 64 * npfns, PMD_SIZE);
else if (nd_pfn->mode == PFN_MODE_RAM)
offset = SZ_8K;
else
goto err;
npfns = (pmem->size - offset) / 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);
pfn_sb->version_major = cpu_to_le16(1);
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;
}
static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
{
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
struct device *dev = &nd_pfn->dev;
struct vmem_altmap *altmap;
struct nd_region *nd_region;
struct nd_pfn_sb *pfn_sb;
struct pmem_device *pmem;
phys_addr_t offset;
int rc;
if (!nd_pfn->uuid || !nd_pfn->ndns)
return -ENODEV;
nd_region = to_nd_region(dev->parent);
rc = nd_pfn_init(nd_pfn);
if (rc)
return rc;
if (PAGE_SIZE != SZ_4K) {
dev_err(dev, "only supported on systems with 4K PAGE_SIZE\n");
return -ENXIO;
}
if (nsio->res.start & ND_PFN_MASK) {
dev_err(dev, "%s not memory hotplug section aligned\n",
dev_name(&ndns->dev));
return -ENXIO;
}
pfn_sb = nd_pfn->pfn_sb;
offset = le64_to_cpu(pfn_sb->dataoff);
nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
if (nd_pfn->mode == PFN_MODE_RAM) {
if (offset != SZ_8K)
return -EINVAL;
nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
altmap = NULL;
} else {
rc = -ENXIO;
goto err;
}
/* establish pfn range for lookup, and switch to direct map */
pmem = dev_get_drvdata(dev);
devm_memunmap(dev, (void __force *) pmem->virt_addr);
pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &nsio->res);
if (IS_ERR(pmem->virt_addr)) {
rc = PTR_ERR(pmem->virt_addr);
goto err;
}
/* attach pmem disk in "pfn-mode" */
pmem->data_offset = offset;
rc = pmem_attach_disk(dev, ndns, pmem);
if (rc)
goto err;
return rc;
err:
nvdimm_namespace_detach_pfn(ndns);
return rc;
}
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 (is_nd_btt(dev))
return nvdimm_namespace_attach_btt(ndns);
if (is_nd_pfn(dev))
return nvdimm_namespace_attach_pfn(ndns);
if (nd_btt_probe(ndns, pmem) == 0) {
/* we'll come back as btt-pmem */
return -ENXIO;
}
if (nd_pfn_probe(ndns, pmem) == 0) {
/* we'll come back as pfn-pmem */
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;
}
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,
.drv = {
.name = "nd_pmem",
},
.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
};
static int __init pmem_init(void)
{
int error;
pmem_major = register_blkdev(0, "pmem");
if (pmem_major < 0)
return pmem_major;
error = nd_driver_register(&nd_pmem_driver);
if (error) {
unregister_blkdev(pmem_major, "pmem");
return error;
}
return 0;
}
module_init(pmem_init);
static void pmem_exit(void)
{
driver_unregister(&nd_pmem_driver.drv);
unregister_blkdev(pmem_major, "pmem");
}
module_exit(pmem_exit);
MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
MODULE_LICENSE("GPL v2");