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Commit c1d6e828 authored by Dan Williams's avatar Dan Williams
Browse files

pmem: add dax_operations support 



Setup a dax_device to have the same lifetime as the pmem block device
and add a ->direct_access() method that is equivalent to
pmem_direct_access(). Once fs/dax.c has been converted to use
dax_operations the old pmem_direct_access() will be removed.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 6568b08b

drivers/dax/dax.h

+0 −7
Original line number Diff line number Diff line
@@ -13,13 +13,6 @@ 
#ifndef __DAX_H__

#define __DAX_H__

struct dax_device;

struct dax_operations;

struct dax_device *alloc_dax(void *private, const char *host,

		const struct dax_operations *ops);

void put_dax(struct dax_device *dax_dev);

bool dax_alive(struct dax_device *dax_dev);

void kill_dax(struct dax_device *dax_dev);

struct dax_device *inode_dax(struct inode *inode);

struct inode *dax_inode(struct dax_device *dax_dev);

void *dax_get_private(struct dax_device *dax_dev);

#endif /* __DAX_H__ */

drivers/nvdimm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ if LIBNVDIMM 
config BLK_DEV_PMEM

	tristate "PMEM: Persistent memory block device support"

	default LIBNVDIMM

	select DAX

	select ND_BTT if BTT

	select ND_PFN if NVDIMM_PFN

	help

drivers/nvdimm/pmem.c

+48 −13
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/pfn_t.h>

#include <linux/slab.h>

#include <linux/pmem.h>

#include <linux/dax.h>

#include <linux/nd.h>

#include "pmem.h"

#include "pfn.h"
@@ -199,13 +200,13 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector, 
}



/* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */

__weak long pmem_direct_access(struct block_device *bdev, sector_t sector,

		      void **kaddr, pfn_t *pfn, long size)

__weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn)

{

	struct pmem_device *pmem = bdev->bd_queue->queuedata;

	resource_size_t offset = sector * 512 + pmem->data_offset;

	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;



	if (unlikely(is_bad_pmem(&pmem->bb, sector, size)))

	if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,

					PFN_PHYS(nr_pages))))

		return -EIO;

	*kaddr = pmem->virt_addr + offset;

	*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
@@ -215,26 +216,51 @@ __weak long pmem_direct_access(struct block_device *bdev, sector_t sector, 
	 * requested range.

	 */

	if (unlikely(pmem->bb.count))

		return size;

	return pmem->size - pmem->pfn_pad - offset;

		return nr_pages;

	return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);

}



static long pmem_blk_direct_access(struct block_device *bdev, sector_t sector,

		void **kaddr, pfn_t *pfn, long size)

{

	struct pmem_device *pmem = bdev->bd_queue->queuedata;



	return __pmem_direct_access(pmem, PHYS_PFN(sector * 512),

			PHYS_PFN(size), kaddr, pfn);

}



static const struct block_device_operations pmem_fops = {

	.owner =		THIS_MODULE,

	.rw_page =		pmem_rw_page,

	.direct_access =	pmem_direct_access,

	.direct_access =	pmem_blk_direct_access,

	.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 const struct dax_operations pmem_dax_ops = {

	.direct_access = pmem_dax_direct_access,

};



static void pmem_release_queue(void *q)

{

	blk_cleanup_queue(q);

}



static void pmem_release_disk(void *disk)

static void pmem_release_disk(void *__pmem)

{

	del_gendisk(disk);

	put_disk(disk);

	struct pmem_device *pmem = __pmem;



	kill_dax(pmem->dax_dev);

	put_dax(pmem->dax_dev);

	del_gendisk(pmem->disk);

	put_disk(pmem->disk);

}



static int pmem_attach_disk(struct device *dev,
@@ -245,6 +271,7 @@ static int pmem_attach_disk(struct device *dev, 
	struct vmem_altmap __altmap, *altmap = NULL;

	struct resource *res = &nsio->res;

	struct nd_pfn *nd_pfn = NULL;

	struct dax_device *dax_dev;

	int nid = dev_to_node(dev);

	struct nd_pfn_sb *pfn_sb;

	struct pmem_device *pmem;
@@ -325,6 +352,7 @@ static int pmem_attach_disk(struct device *dev, 
	disk = alloc_disk_node(0, nid);

	if (!disk)

		return -ENOMEM;

	pmem->disk = disk;



	disk->fops		= &pmem_fops;

	disk->queue		= q;
@@ -336,9 +364,16 @@ static int pmem_attach_disk(struct device *dev, 
		return -ENOMEM;

	nvdimm_badblocks_populate(nd_region, &pmem->bb, res);

	disk->bb = &pmem->bb;

	device_add_disk(dev, disk);



	if (devm_add_action_or_reset(dev, pmem_release_disk, disk))

	dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);

	if (!dax_dev) {

		put_disk(disk);

		return -ENOMEM;

	}

	pmem->dax_dev = dax_dev;



	device_add_disk(dev, disk);

	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))

		return -ENOMEM;



	revalidate_disk(disk);

drivers/nvdimm/pmem.h

+5 −2
Original line number Diff line number Diff line
@@ -5,8 +5,6 @@ 
#include <linux/pfn_t.h>

#include <linux/fs.h>



long pmem_direct_access(struct block_device *bdev, sector_t sector,

		      void **kaddr, pfn_t *pfn, long size);

/* this definition is in it's own header for tools/testing/nvdimm to consume */

struct pmem_device {

	/* One contiguous memory region per device */
@@ -20,5 +18,10 @@ struct pmem_device { 
	/* trim size when namespace capacity has been section aligned */

	u32			pfn_pad;

	struct badblocks	bb;

	struct dax_device	*dax_dev;

	struct gendisk		*disk;

};



long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,

		long nr_pages, void **kaddr, pfn_t *pfn);

#endif /* __NVDIMM_PMEM_H__ */

include/linux/dax.h

+6 −0
Original line number Diff line number Diff line
@@ -21,6 +21,12 @@ struct dax_operations { 
int dax_read_lock(void);

void dax_read_unlock(int id);

struct dax_device *dax_get_by_host(const char *host);

struct dax_device *alloc_dax(void *private, const char *host,

		const struct dax_operations *ops);

void put_dax(struct dax_device *dax_dev);

bool dax_alive(struct dax_device *dax_dev);

void kill_dax(struct dax_device *dax_dev);

void *dax_get_private(struct dax_device *dax_dev);



/*

 * We use lowest available bit in exceptional entry for locking, one bit for