[resend PATCH v2 21/33] filesystem-dax: convert to dax_copy_from_iter()

From: Dan Williams
Date: Mon Apr 17 2017 - 15:16:52 EST


Now that all possible providers of the dax_operations copy_from_iter
method are implemented, switch filesytem-dax to call the driver rather
than copy_to_iter_pmem.

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
arch/x86/include/asm/pmem.h | 50 -------------------------------------------
fs/dax.c | 3 ++-
include/linux/pmem.h | 24 ---------------------
3 files changed, 2 insertions(+), 75 deletions(-)

diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h
index d5a22bac9988..60e8edbe0205 100644
--- a/arch/x86/include/asm/pmem.h
+++ b/arch/x86/include/asm/pmem.h
@@ -66,56 +66,6 @@ static inline void arch_wb_cache_pmem(void *addr, size_t size)
}

/**
- * arch_copy_from_iter_pmem - copy data from an iterator to PMEM
- * @addr: PMEM destination address
- * @bytes: number of bytes to copy
- * @i: iterator with source data
- *
- * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
- */
-static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes,
- struct iov_iter *i)
-{
- size_t len;
-
- /* TODO: skip the write-back by always using non-temporal stores */
- len = copy_from_iter_nocache(addr, bytes, i);
-
- /*
- * In the iovec case on x86_64 copy_from_iter_nocache() uses
- * non-temporal stores for the bulk of the transfer, but we need
- * to manually flush if the transfer is unaligned. A cached
- * memory copy is used when destination or size is not naturally
- * aligned. That is:
- * - Require 8-byte alignment when size is 8 bytes or larger.
- * - Require 4-byte alignment when size is 4 bytes.
- *
- * In the non-iovec case the entire destination needs to be
- * flushed.
- */
- if (iter_is_iovec(i)) {
- unsigned long flushed, dest = (unsigned long) addr;
-
- if (bytes < 8) {
- if (!IS_ALIGNED(dest, 4) || (bytes != 4))
- arch_wb_cache_pmem(addr, 1);
- } else {
- if (!IS_ALIGNED(dest, 8)) {
- dest = ALIGN(dest, boot_cpu_data.x86_clflush_size);
- arch_wb_cache_pmem(addr, 1);
- }
-
- flushed = dest - (unsigned long) addr;
- if (bytes > flushed && !IS_ALIGNED(bytes - flushed, 8))
- arch_wb_cache_pmem(addr + bytes - 1, 1);
- }
- } else
- arch_wb_cache_pmem(addr, bytes);
-
- return len;
-}
-
-/**
* arch_clear_pmem - zero a PMEM memory range
* @addr: virtual start address
* @size: number of bytes to zero
diff --git a/fs/dax.c b/fs/dax.c
index ce9dc9c3e829..11b9909c91df 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1061,7 +1061,8 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
map_len = end - pos;

if (iov_iter_rw(iter) == WRITE)
- map_len = copy_from_iter_pmem(kaddr, map_len, iter);
+ map_len = dax_copy_from_iter(dax_dev, pgoff, kaddr,
+ map_len, iter);
else
map_len = copy_to_iter(kaddr, map_len, iter);
if (map_len <= 0) {
diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index 71ecf3d46aac..9d542a5600e4 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -31,13 +31,6 @@ static inline void arch_memcpy_to_pmem(void *dst, const void *src, size_t n)
BUG();
}

-static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes,
- struct iov_iter *i)
-{
- BUG();
- return 0;
-}
-
static inline void arch_clear_pmem(void *addr, size_t size)
{
BUG();
@@ -80,23 +73,6 @@ static inline void memcpy_to_pmem(void *dst, const void *src, size_t n)
}

/**
- * copy_from_iter_pmem - copy data from an iterator to PMEM
- * @addr: PMEM destination address
- * @bytes: number of bytes to copy
- * @i: iterator with source data
- *
- * Copy data from the iterator 'i' to the PMEM buffer starting at 'addr'.
- * See blkdev_issue_flush() note for memcpy_to_pmem().
- */
-static inline size_t copy_from_iter_pmem(void *addr, size_t bytes,
- struct iov_iter *i)
-{
- if (arch_has_pmem_api())
- return arch_copy_from_iter_pmem(addr, bytes, i);
- return copy_from_iter_nocache(addr, bytes, i);
-}
-
-/**
* clear_pmem - zero a PMEM memory range
* @addr: virtual start address
* @size: number of bytes to zero