Commit 81f55870 authored by Dan Williams's avatar Dan Williams
Browse files

x86, dax: replace clear_pmem() with open coded memset + dax_ops->flush 



The clear_pmem() helper simply combines a memset() plus a cache flush.
Now that the flush routine is optionally provided by the dax device
driver we can avoid unnecessary cache management on dax devices fronting
volatile memory.

With clear_pmem() gone we can follow on with a patch to make pmem cache
management completely defined within the pmem driver.

Cc: <x86@kernel.org>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 6318770a

arch/x86/include/asm/pmem.h

+0 −13
Original line number Diff line number Diff line
@@ -65,19 +65,6 @@ static inline void arch_wb_cache_pmem(void *addr, size_t size) 
		clwb(p);

}



/**

 * arch_clear_pmem - zero a PMEM memory range

 * @addr:	virtual start address

 * @size:	number of bytes to zero

 *

 * Write zeros into the memory range starting at 'addr' for 'size' bytes.

 */

static inline void arch_clear_pmem(void *addr, size_t size)

{

	memset(addr, 0, size);

	arch_wb_cache_pmem(addr, size);

}



static inline void arch_invalidate_pmem(void *addr, size_t size)

{

	clflush_cache_range(addr, size);

fs/dax.c

+2 −1
Original line number Diff line number Diff line
@@ -975,7 +975,8 @@ int __dax_zero_page_range(struct block_device *bdev, 
			dax_read_unlock(id);

			return rc;

		}

		clear_pmem(kaddr + offset, size);

		memset(kaddr + offset, 0, size);

		dax_flush(dax_dev, pgoff, kaddr + offset, size);

		dax_read_unlock(id);

	}

	return 0;

include/linux/pmem.h

+0 −21
Original line number Diff line number Diff line
@@ -31,11 +31,6 @@ static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n) 
	BUG();

}



static inline void arch_clear_pmem(void *addr, size_t size)

{

	BUG();

}



static inline void arch_wb_cache_pmem(void *addr, size_t size)

{

	BUG();
@@ -72,22 +67,6 @@ static inline void memcpy_to_pmem(void *dst, const void *src, size_t n) 
		memcpy(dst, src, n);

}



/**

 * clear_pmem - zero a PMEM memory range

 * @addr:	virtual start address

 * @size:	number of bytes to zero

 *

 * Write zeros into the memory range starting at 'addr' for 'size' bytes.

 * See blkdev_issue_flush() note for memcpy_to_pmem().

 */

static inline void clear_pmem(void *addr, size_t size)

{

	if (arch_has_pmem_api())

		arch_clear_pmem(addr, size);

	else

		memset(addr, 0, size);

}



/**

 * invalidate_pmem - flush a pmem range from the cache hierarchy

 * @addr:	virtual start address

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