x86: Use clflushopt in clflush_cache_range
If clflushopt is available on the system, use it instead of clflush in
clflush_cache_range.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Link: http://lkml.kernel.org/r/1393441612-19729-3-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index b3b19f4..b1c4672 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -126,8 +126,8 @@
* @vaddr: virtual start address
* @size: number of bytes to flush
*
- * clflush is an unordered instruction which needs fencing with mfence
- * to avoid ordering issues.
+ * clflushopt is an unordered instruction which needs fencing with mfence or
+ * sfence to avoid ordering issues.
*/
void clflush_cache_range(void *vaddr, unsigned int size)
{
@@ -136,11 +136,11 @@
mb();
for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
- clflush(vaddr);
+ clflushopt(vaddr);
/*
* Flush any possible final partial cacheline:
*/
- clflush(vend);
+ clflushopt(vend);
mb();
}