Commit f25c69bd authored by Ben Hutchings's avatar Ben Hutchings Committed by Greg Kroah-Hartman

x86, pmem: Fix cache flushing for iovec write < 8 bytes

commit 8376efd3 upstream.

Commit 11e63f6d added cache flushing for unaligned writes from an
iovec, covering the first and last cache line of a >= 8 byte write and
the first cache line of a < 8 byte write.  But an unaligned write of
2-7 bytes can still cover two cache lines, so make sure we flush both
in that case.

Fixes: 11e63f6d ("x86, pmem: fix broken __copy_user_nocache ...")
Signed-off-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 20fd61db
......@@ -103,7 +103,7 @@ static inline size_t arch_copy_from_iter_pmem(void *addr, size_t bytes,
if (bytes < 8) {
if (!IS_ALIGNED(dest, 4) || (bytes != 4))
arch_wb_cache_pmem(addr, 1);
arch_wb_cache_pmem(addr, bytes);
} else {
if (!IS_ALIGNED(dest, 8)) {
dest = ALIGN(dest, boot_cpu_data.x86_clflush_size);
......
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