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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: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2017-05-29 13:12:20 -07:00
parent 6318770a7d
commit 81f558701a
3 changed files with 2 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
arch/x86/include/asm/pmem.h
View File

@ -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);

3
fs/dax.c
View File

@ -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;

21
include/linux/pmem.h
View File

@ -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