1 files changed, 44 insertions, 0 deletions

diff --git a/arch/arm/lib/memzero.S b/arch/arm/lib/memzero.S
index abf2508e8221..b8f79d80ee9b 100644
--- a/arch/arm/lib/memzero.S
+++ b/arch/arm/lib/memzero.S
@@ -39,6 +39,9 @@ ENTRY(__memzero)
  */
         cmp     r1, #16                 @ 1 we can skip this chunk if we
         blt     4f                      @ 1 have < 16 bytes
+
+#if ! CALGN(1)+0
+
 /*
  * We need an extra register for this loop - save the return address and
  * use the LR
@@ -64,6 +67,47 @@ ENTRY(__memzero)
         stmneia r0!, {r2, r3, ip, lr}   @ 4
         ldr     lr, [sp], #4            @ 1
 
+#else
+
+/*
+ * This version aligns the destination pointer in order to write
+ * whole cache lines at once.
+ */
+
+        stmfd   sp!, {r4-r7, lr}
+        mov     r4, r2
+        mov     r5, r2
+        mov     r6, r2
+        mov     r7, r2
+        mov     ip, r2
+        mov     lr, r2
+
+        cmp     r1, #96
+        andgts  ip, r0, #31
+        ble     3f
+
+        rsb     ip, ip, #32
+        sub     r1, r1, ip
+        movs    ip, ip, lsl #(32 - 4)
+        stmcsia r0!, {r4, r5, r6, r7}
+        stmmiia r0!, {r4, r5}
+        movs    ip, ip, lsl #2
+        strcs   r2, [r0], #4
+
+3:      subs    r1, r1, #64
+        stmgeia r0!, {r2-r7, ip, lr}
+        stmgeia r0!, {r2-r7, ip, lr}
+        bgt     3b
+        ldmeqfd sp!, {r4-r7, pc}
+
+        tst     r1, #32
+        stmneia r0!, {r2-r7, ip, lr}
+        tst     r1, #16
+        stmneia r0!, {r4-r7}
+        ldmfd   sp!, {r4-r7, lr}
+
+#endif
+
 4:      tst     r1, #8                  @ 1 8 bytes or more?
         stmneia r0!, {r2, r3}           @ 2
         tst     r1, #4                  @ 1 4 bytes or more?