arm64: copy_to-from-in_user optimization using copy template

This patch optimize copy_to-from-in_user for arm 64bit architecture. The
copy template is used as template file for all the copy*.S files. Minor
change was made to it to accommodate the copy to/from/in user files.

Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 44 insertions, 34 deletions

diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 1be9ef27be97..4699cd74f87e 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -18,6 +18,7 @@
 
 #include <asm/alternative.h>
 #include <asm/assembler.h>
+#include <asm/cache.h>
 #include <asm/cpufeature.h>
 #include <asm/sysreg.h>
 
@@ -31,49 +32,58 @@
  * Returns:
  *      x0 - bytes not copied
  */
+
+        .macro ldrb1 ptr, regB, val
+        USER(9998f, ldrb  \ptr, [\regB], \val)
+        .endm
+
+        .macro strb1 ptr, regB, val
+        strb \ptr, [\regB], \val
+        .endm
+
+        .macro ldrh1 ptr, regB, val
+        USER(9998f, ldrh  \ptr, [\regB], \val)
+        .endm
+
+        .macro strh1 ptr, regB, val
+        strh \ptr, [\regB], \val
+        .endm
+
+        .macro ldr1 ptr, regB, val
+        USER(9998f, ldr \ptr, [\regB], \val)
+        .endm
+
+        .macro str1 ptr, regB, val
+        str \ptr, [\regB], \val
+        .endm
+
+        .macro ldp1 ptr, regB, regC, val
+        USER(9998f, ldp \ptr, \regB, [\regC], \val)
+        .endm
+
+        .macro stp1 ptr, regB, regC, val
+        stp \ptr, \regB, [\regC], \val
+        .endm
+
+end     .req    x5
 ENTRY(__copy_from_user)
 ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_HAS_PAN, \
             CONFIG_ARM64_PAN)
-        add     x5, x1, x2                      // upper user buffer boundary
-        subs    x2, x2, #16
-        b.mi    1f
-0:
-USER(9f, ldp    x3, x4, [x1], #16)
-        subs    x2, x2, #16
-        stp     x3, x4, [x0], #16
-        b.pl    0b
-1:      adds    x2, x2, #8
-        b.mi    2f
-USER(9f, ldr    x3, [x1], #8    )
-        sub     x2, x2, #8
-        str     x3, [x0], #8
-2:      adds    x2, x2, #4
-        b.mi    3f
-USER(9f, ldr    w3, [x1], #4    )
-        sub     x2, x2, #4
-        str     w3, [x0], #4
-3:      adds    x2, x2, #2
-        b.mi    4f
-USER(9f, ldrh   w3, [x1], #2    )
-        sub     x2, x2, #2
-        strh    w3, [x0], #2
-4:      adds    x2, x2, #1
-        b.mi    5f
-USER(9f, ldrb   w3, [x1]        )
-        strb    w3, [x0]
-5:      mov     x0, #0
+        add     end, x0, x2
+#include "copy_template.S"
 ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_HAS_PAN, \
             CONFIG_ARM64_PAN)
+        mov     x0, #0                          // Nothing to copy
         ret
 ENDPROC(__copy_from_user)
 
         .section .fixup,"ax"
         .align  2
-9:      sub     x2, x5, x1
-        mov     x3, x2
-10:     strb    wzr, [x0], #1                   // zero remaining buffer space
-        subs    x3, x3, #1
-        b.ne    10b
-        mov     x0, x2                          // bytes not copied
+9998:
+        sub     x0, end, dst
+9999:
+        strb    wzr, [dst], #1                  // zero remaining buffer space
+        cmp     dst, end
+        b.lo    9999b
         ret
         .previous