Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

[platform/kernel/linux-starfive.git] / lib / string.c

diff --git a/lib/string.c b/lib/string.c
index 77bd0b1..b2de45a 100644 (file)
--- a/lib/string.c
+++ b/lib/string.c
@@ -29,6 +29,7 @@
 #include <linux/errno.h>
 #include <linux/slab.h>
 
+#include <asm/unaligned.h>
 #include <asm/byteorder.h>
 #include <asm/word-at-a-time.h>
 #include <asm/page.h>
@@ -935,6 +936,21 @@ __visible int memcmp(const void *cs, const void *ct, size_t count)
        const unsigned char *su1, *su2;
        int res = 0;
 
+#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+       if (count >= sizeof(unsigned long)) {
+               const unsigned long *u1 = cs;
+               const unsigned long *u2 = ct;
+               do {
+                       if (get_unaligned(u1) != get_unaligned(u2))
+                               break;
+                       u1++;
+                       u2++;
+                       count -= sizeof(unsigned long);
+               } while (count >= sizeof(unsigned long));
+               cs = u1;
+               ct = u2;
+       }
+#endif
        for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
                if ((res = *su1 - *su2) != 0)
                        break;