Implement memmove in C, dropping the asm implementation which does no
particular optimisation & was duplicated needlessly for octeon.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
arch/mips/cavium-octeon/octeon-memcpy.S | 50 +----------------------------
arch/mips/lib/Makefile | 1 +
arch/mips/lib/memcpy.S | 56 +--------------------------------
arch/mips/lib/memmove.c | 39 +++++++++++++++++++++++
4 files changed, 42 insertions(+), 104 deletions(-)
create mode 100644 arch/mips/lib/memmove.c
diff --git a/arch/mips/cavium-octeon/octeon-memcpy.S b/arch/mips/cavium-octeon/octeon-memcpy.S
index 7d96d9c..4336316 100644
--- a/arch/mips/cavium-octeon/octeon-memcpy.S
+++ b/arch/mips/cavium-octeon/octeon-memcpy.S
@@ -3,7 +3,7 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Unified implementation of memcpy, memmove and the __copy_user backend.
+ * Unified implementation of memcpy and the __copy_user backend.
*
* Copyright (C) 1998, 99, 2000, 01, 2002 Ralf Baechle (ralf@xxxxxxx)
* Copyright (C) 1999, 2000, 01, 2002 Silicon Graphics, Inc.
@@ -66,9 +66,6 @@
*
* The exception handlers for stores adjust len (if necessary) and return.
* These handlers do not need to overwrite any data.
- *
- * For __rmemcpy and memmove an exception is always a kernel bug, therefore
- * they're not protected.
*/
#define EXC(inst_reg,addr,handler) \
@@ -460,48 +457,3 @@ s_exc_p1:
s_exc:
jr ra
nop
-
- .align 5
-LEAF(memmove)
-EXPORT_SYMBOL(memmove)
- ADD t0, a0, a2
- ADD t1, a1, a2
- sltu t0, a1, t0 # dst + len <= src -> memcpy
- sltu t1, a0, t1 # dst >= src + len -> memcpy
- and t0, t1
- beqz t0, __memcpy
- move v0, a0 /* return value */
- beqz a2, r_out
- END(memmove)
-
- /* fall through to __rmemcpy */
-LEAF(__rmemcpy) /* a0=dst a1=src a2=len */
- sltu t0, a1, a0
- beqz t0, r_end_bytes_up # src >= dst
- nop
- ADD a0, a2 # dst = dst + len
- ADD a1, a2 # src = src + len
-
-r_end_bytes:
- lb t0, -1(a1)
- SUB a2, a2, 0x1
- sb t0, -1(a0)
- SUB a1, a1, 0x1
- bnez a2, r_end_bytes
- SUB a0, a0, 0x1
-
-r_out:
- jr ra
- move a2, zero
-
-r_end_bytes_up:
- lb t0, (a1)
- SUB a2, a2, 0x1
- sb t0, (a0)
- ADD a1, a1, 0x1
- bnez a2, r_end_bytes_up
- ADD a0, a0, 0x1
-
- jr ra
- move a2, zero
- END(__rmemcpy)
diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile
index c0f0d1d..0040bad 100644
--- a/arch/mips/lib/Makefile
+++ b/arch/mips/lib/Makefile
@@ -6,6 +6,7 @@ lib-y += bitops.o
lib-y += csum_partial.o
lib-y += delay.o
lib-y += memcpy.o
+lib-y += memmove.o
lib-y += memset.o
lib-y += mips-atomic.o
lib-y += strlen_user.o
diff --git a/arch/mips/lib/memcpy.S b/arch/mips/lib/memcpy.S
index c3031f1..b8d34d9 100644
--- a/arch/mips/lib/memcpy.S
+++ b/arch/mips/lib/memcpy.S
@@ -3,7 +3,7 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Unified implementation of memcpy, memmove and the __copy_user backend.
+ * Unified implementation of memcpy and the __copy_user backend.
*
* Copyright (C) 1998, 99, 2000, 01, 2002 Ralf Baechle (ralf@xxxxxxx)
* Copyright (C) 1999, 2000, 01, 2002 Silicon Graphics, Inc.
@@ -82,9 +82,6 @@
*
* The exception handlers for stores adjust len (if necessary) and return.
* These handlers do not need to overwrite any data.
- *
- * For __rmemcpy and memmove an exception is always a kernel bug, therefore
- * they're not protected.
*/
/* Instruction type */
@@ -621,57 +618,6 @@ SEXC(1)
nop
.endm
- .align 5
-LEAF(memmove)
-EXPORT_SYMBOL(memmove)
- ADD t0, a0, a2
- ADD t1, a1, a2
- sltu t0, a1, t0 # dst + len <= src -> memcpy
- sltu t1, a0, t1 # dst >= src + len -> memcpy
- and t0, t1
- beqz t0, .L__memcpy
- move v0, a0 /* return value */
- beqz a2, .Lr_out
- END(memmove)
-
- /* fall through to __rmemcpy */
-LEAF(__rmemcpy) /* a0=dst a1=src a2=len */
- sltu t0, a1, a0
- beqz t0, .Lr_end_bytes_up # src >= dst
- nop
- ADD a0, a2 # dst = dst + len
- ADD a1, a2 # src = src + len
-
-.Lr_end_bytes:
- R10KCBARRIER(0(ra))
- lb t0, -1(a1)
- SUB a2, a2, 0x1
- sb t0, -1(a0)
- SUB a1, a1, 0x1
- .set reorder /* DADDI_WAR */
- SUB a0, a0, 0x1
- bnez a2, .Lr_end_bytes
- .set noreorder
-
-.Lr_out:
- jr ra
- move a2, zero
-
-.Lr_end_bytes_up:
- R10KCBARRIER(0(ra))
- lb t0, (a1)
- SUB a2, a2, 0x1
- sb t0, (a0)
- ADD a1, a1, 0x1
- .set reorder /* DADDI_WAR */
- ADD a0, a0, 0x1
- bnez a2, .Lr_end_bytes_up
- .set noreorder
-
- jr ra
- move a2, zero
- END(__rmemcpy)
-
/*
* t6 is used as a flag to note inatomic mode.
*/
diff --git a/arch/mips/lib/memmove.c b/arch/mips/lib/memmove.c
new file mode 100644
index 0000000..4e902c6
--- /dev/null
+++ b/arch/mips/lib/memmove.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Paul Burton <paul.burton@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/export.h>
+#include <linux/string.h>
+
+extern void *memmove(void *dest, const void *src, size_t count)
+{
+ const char *s = src;
+ const char *s_end = s + count;
+ char *d = dest;
+ char *d_end = dest + count;
+
+ /* Use optimised memcpy when there's no overlap */
+ if ((d_end <= s) || (s_end <= d))
+ return memcpy(dest, src, count);
+
+ if (d <= s) {
+ /* Incrementing copy loop */
+ while (count--)
+ *d++ = *s++;
+ } else {
+ /* Decrementing copy loop */
+ d = d_end;
+ s = s_end;
+ while (count--)
+ *--d = *--s;
+ }
+
+ return dest;
+}
+EXPORT_SYMBOL(memmove);
--
2.10.2
