[U-Boot] [PATCH v3] arm: build arch memset/memcpy in Thumb2 mode
Stefan Agner
stefan at agner.ch
Thu Dec 18 18:10:33 CET 2014
Resynchronize memcpy/memset with kernel 3.17 and build them in
Thumb2 mode (unified syntax). Those assembler files can be built
and linked in ARM mode too, however when calling them from Thumb2
built code, the stack got corrupted and the copy did not succeed
(the exact details have not been traced back). However, the Linux
kernel builds those files in Thumb2 mode. Hence U-Boot should
build them in Thumb2 mode too when CONFIG_SYS_THUMB_BUILD is set.
To build the files without warning, some assembler instructions
had to be replaced with their UAL compliant variant (thanks
Jeroen for this input).
To build the file in Thumb2 mode the implicit-it=always option need
to be set to generate Thumb2 compliant IT instructions where needed.
We add this option to the general AFLAGS when building for Thumb2.
Reviewed-by: Simon Glass <sjg at chromium.org>
Tested-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Stefan Agner <stefan at agner.ch>
---
arch/arm/config.mk | 4 +-
arch/arm/include/asm/assembler.h | 33 ++++++++++--
arch/arm/lib/memcpy.S | 80 +++++++++++++++++++---------
arch/arm/lib/memset.S | 112 ++++++++++++++++++++-------------------
4 files changed, 142 insertions(+), 87 deletions(-)
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index f0eafd6..9a4c270 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -26,7 +26,9 @@ PLATFORM_CPPFLAGS += -D__ARM__
# Choose between ARM/Thumb instruction sets
ifeq ($(CONFIG_SYS_THUMB_BUILD),y)
-PF_CPPFLAGS_ARM := $(call cc-option, -mthumb -mthumb-interwork,\
+AFLAGS_IMPLICIT_IT := $(call as-option,-Wa$(comma)-mimplicit-it=always)
+PF_CPPFLAGS_ARM := $(AFLAGS_IMPLICIT_IT) \
+ $(call cc-option, -mthumb -mthumb-interwork,\
$(call cc-option,-marm,)\
$(call cc-option,-mno-thumb-interwork,)\
)
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 5e4789b..11b80fb 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -14,12 +14,14 @@
* assembler source.
*/
+#include <config.h>
+
/*
* Endian independent macros for shifting bytes within registers.
*/
#ifndef __ARMEB__
-#define pull lsr
-#define push lsl
+#define lspull lsr
+#define lspush lsl
#define get_byte_0 lsl #0
#define get_byte_1 lsr #8
#define get_byte_2 lsr #16
@@ -29,8 +31,8 @@
#define put_byte_2 lsl #16
#define put_byte_3 lsl #24
#else
-#define pull lsl
-#define push lsr
+#define lspull lsl
+#define lspush lsr
#define get_byte_0 lsr #24
#define get_byte_1 lsr #16
#define get_byte_2 lsr #8
@@ -54,7 +56,28 @@
#define PLD(code...)
#endif
+ .irp c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo
+ .macro ret\c, reg
+#if defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__)
+ mov\c pc, \reg
+#else
+ .ifeqs "\reg", "lr"
+ bx\c \reg
+ .else
+ mov\c pc, \reg
+ .endif
+#endif
+ .endm
+ .endr
+
/*
- * Cache alligned
+ * Cache aligned, used for optimized memcpy/memset
+ * In the kernel this is only enabled for Feroceon CPU's...
+ * We disable it especially for Thumb builds since those instructions
+ * are not made in a Thumb ready way...
*/
+#ifdef CONFIG_SYS_THUMB_BUILD
+#define CALGN(code...)
+#else
#define CALGN(code...) code
+#endif
diff --git a/arch/arm/lib/memcpy.S b/arch/arm/lib/memcpy.S
index f655256..eeaf003 100644
--- a/arch/arm/lib/memcpy.S
+++ b/arch/arm/lib/memcpy.S
@@ -10,9 +10,14 @@
* published by the Free Software Foundation.
*/
+#include <linux/linkage.h>
#include <asm/assembler.h>
+#ifdef CONFIG_SYS_THUMB_BUILD
+#define W(instr) instr.w
+#else
#define W(instr) instr
+#endif
#define LDR1W_SHIFT 0
#define STR1W_SHIFT 0
@@ -30,7 +35,7 @@
.endm
.macro ldr1b ptr reg cond=al abort
- ldr\cond\()b \reg, [\ptr], #1
+ ldrb\cond\() \reg, [\ptr], #1
.endm
.macro str1w ptr reg abort
@@ -42,7 +47,7 @@
.endm
.macro str1b ptr reg cond=al abort
- str\cond\()b \reg, [\ptr], #1
+ strb\cond\() \reg, [\ptr], #1
.endm
.macro enter reg1 reg2
@@ -56,10 +61,12 @@
.text
/* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
-
-.globl memcpy
-memcpy:
-
+ .syntax unified
+#ifdef CONFIG_SYS_THUMB_BUILD
+ .thumb
+ .thumb_func
+#endif
+ENTRY(memcpy)
cmp r0, r1
moveq pc, lr
@@ -79,7 +86,7 @@ memcpy:
CALGN( ands ip, r0, #31 )
CALGN( rsb r3, ip, #32 )
- CALGN( sbcnes r4, r3, r2 ) @ C is always set here
+ CALGN( sbcsne r4, r3, r2 ) @ C is always set here
CALGN( bcs 2f )
CALGN( adr r4, 6f )
CALGN( subs r2, r2, r3 ) @ C gets set
@@ -178,7 +185,7 @@ memcpy:
CALGN( ands ip, r0, #31 )
CALGN( rsb ip, ip, #32 )
- CALGN( sbcnes r4, ip, r2 ) @ C is always set here
+ CALGN( sbcsne r4, ip, r2 ) @ C is always set here
CALGN( subcc r2, r2, ip )
CALGN( bcc 15f )
@@ -193,24 +200,24 @@ memcpy:
12: PLD( pld [r1, #124] )
13: ldr4w r1, r4, r5, r6, r7, abort=19f
- mov r3, lr, pull #\pull
+ mov r3, lr, lspull #\pull
subs r2, r2, #32
ldr4w r1, r8, r9, ip, lr, abort=19f
- orr r3, r3, r4, push #\push
- mov r4, r4, pull #\pull
- orr r4, r4, r5, push #\push
- mov r5, r5, pull #\pull
- orr r5, r5, r6, push #\push
- mov r6, r6, pull #\pull
- orr r6, r6, r7, push #\push
- mov r7, r7, pull #\pull
- orr r7, r7, r8, push #\push
- mov r8, r8, pull #\pull
- orr r8, r8, r9, push #\push
- mov r9, r9, pull #\pull
- orr r9, r9, ip, push #\push
- mov ip, ip, pull #\pull
- orr ip, ip, lr, push #\push
+ orr r3, r3, r4, lspush #\push
+ mov r4, r4, lspull #\pull
+ orr r4, r4, r5, lspush #\push
+ mov r5, r5, lspull #\pull
+ orr r5, r5, r6, lspush #\push
+ mov r6, r6, lspull #\pull
+ orr r6, r6, r7, lspush #\push
+ mov r7, r7, lspull #\pull
+ orr r7, r7, r8, lspush #\push
+ mov r8, r8, lspull #\pull
+ orr r8, r8, r9, lspush #\push
+ mov r9, r9, lspull #\pull
+ orr r9, r9, ip, lspush #\push
+ mov ip, ip, lspull #\pull
+ orr ip, ip, lr, lspush #\push
str8w r0, r3, r4, r5, r6, r7, r8, r9, ip, , abort=19f
bge 12b
PLD( cmn r2, #96 )
@@ -221,10 +228,10 @@ memcpy:
14: ands ip, r2, #28
beq 16f
-15: mov r3, lr, pull #\pull
+15: mov r3, lr, lspull #\pull
ldr1w r1, lr, abort=21f
subs ip, ip, #4
- orr r3, r3, lr, push #\push
+ orr r3, r3, lr, lspush #\push
str1w r0, r3, abort=21f
bgt 15b
CALGN( cmp r2, #0 )
@@ -241,3 +248,24 @@ memcpy:
17: forward_copy_shift pull=16 push=16
18: forward_copy_shift pull=24 push=8
+
+
+/*
+ * Abort preamble and completion macros.
+ * If a fixup handler is required then those macros must surround it.
+ * It is assumed that the fixup code will handle the private part of
+ * the exit macro.
+ */
+
+ .macro copy_abort_preamble
+19: ldmfd sp!, {r5 - r9}
+ b 21f
+20: ldmfd sp!, {r5 - r8}
+21:
+ .endm
+
+ .macro copy_abort_end
+ ldmfd sp!, {r4, pc}
+ .endm
+
+ENDPROC(memcpy)
diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S
index 0cdf895..7208f20 100644
--- a/arch/arm/lib/memset.S
+++ b/arch/arm/lib/memset.S
@@ -9,32 +9,25 @@
*
* ASM optimised string functions
*/
+#include <linux/linkage.h>
#include <asm/assembler.h>
.text
.align 5
- .word 0
-1: subs r2, r2, #4 @ 1 do we have enough
- blt 5f @ 1 bytes to align with?
- cmp r3, #2 @ 1
- strltb r1, [r0], #1 @ 1
- strleb r1, [r0], #1 @ 1
- strb r1, [r0], #1 @ 1
- add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3))
-/*
- * The pointer is now aligned and the length is adjusted. Try doing the
- * memset again.
- */
-
-.globl memset
-memset:
+ .syntax unified
+#ifdef CONFIG_SYS_THUMB_BUILD
+ .thumb
+ .thumb_func
+#endif
+ENTRY(memset)
ands r3, r0, #3 @ 1 unaligned?
- bne 1b @ 1
+ mov ip, r0 @ preserve r0 as return value
+ bne 6f @ 1
/*
- * we know that the pointer in r0 is aligned to a word boundary.
+ * we know that the pointer in ip is aligned to a word boundary.
*/
- orr r1, r1, r1, lsl #8
+1: orr r1, r1, r1, lsl #8
orr r1, r1, r1, lsl #16
mov r3, r1
cmp r2, #16
@@ -43,29 +36,28 @@ memset:
#if ! CALGN(1)+0
/*
- * We need an extra register for this loop - save the return address and
- * use the LR
+ * We need 2 extra registers for this loop - use r8 and the LR
*/
- str lr, [sp, #-4]!
- mov ip, r1
+ stmfd sp!, {r8, lr}
+ mov r8, r1
mov lr, r1
2: subs r2, r2, #64
- stmgeia r0!, {r1, r3, ip, lr} @ 64 bytes at a time.
- stmgeia r0!, {r1, r3, ip, lr}
- stmgeia r0!, {r1, r3, ip, lr}
- stmgeia r0!, {r1, r3, ip, lr}
+ stmiage ip!, {r1, r3, r8, lr} @ 64 bytes at a time.
+ stmiage ip!, {r1, r3, r8, lr}
+ stmiage ip!, {r1, r3, r8, lr}
+ stmiage ip!, {r1, r3, r8, lr}
bgt 2b
- ldmeqfd sp!, {pc} @ Now <64 bytes to go.
+ ldmfdeq sp!, {r8, pc} @ Now <64 bytes to go.
/*
* No need to correct the count; we're only testing bits from now on
*/
tst r2, #32
- stmneia r0!, {r1, r3, ip, lr}
- stmneia r0!, {r1, r3, ip, lr}
+ stmiane ip!, {r1, r3, r8, lr}
+ stmiane ip!, {r1, r3, r8, lr}
tst r2, #16
- stmneia r0!, {r1, r3, ip, lr}
- ldr lr, [sp], #4
+ stmiane ip!, {r1, r3, r8, lr}
+ ldmfd sp!, {r8, lr}
#else
@@ -74,53 +66,63 @@ memset:
* whole cache lines at once.
*/
- stmfd sp!, {r4-r7, lr}
+ stmfd sp!, {r4-r8, lr}
mov r4, r1
mov r5, r1
mov r6, r1
mov r7, r1
- mov ip, r1
+ mov r8, r1
mov lr, r1
cmp r2, #96
- tstgt r0, #31
+ tstgt ip, #31
ble 3f
- and ip, r0, #31
- rsb ip, ip, #32
- sub r2, r2, ip
- movs ip, ip, lsl #(32 - 4)
- stmcsia r0!, {r4, r5, r6, r7}
- stmmiia r0!, {r4, r5}
- tst ip, #(1 << 30)
- mov ip, r1
- strne r1, [r0], #4
+ and r8, ip, #31
+ rsb r8, r8, #32
+ sub r2, r2, r8
+ movs r8, r8, lsl #(32 - 4)
+ stmiacs ip!, {r4, r5, r6, r7}
+ stmiami ip!, {r4, r5}
+ tst r8, #(1 << 30)
+ mov r8, r1
+ strne r1, [ip], #4
3: subs r2, r2, #64
- stmgeia r0!, {r1, r3-r7, ip, lr}
- stmgeia r0!, {r1, r3-r7, ip, lr}
+ stmiage ip!, {r1, r3-r8, lr}
+ stmiage ip!, {r1, r3-r8, lr}
bgt 3b
- ldmeqfd sp!, {r4-r7, pc}
+ ldmfdeq sp!, {r4-r8, pc}
tst r2, #32
- stmneia r0!, {r1, r3-r7, ip, lr}
+ stmiane ip!, {r1, r3-r8, lr}
tst r2, #16
- stmneia r0!, {r4-r7}
- ldmfd sp!, {r4-r7, lr}
+ stmiane ip!, {r4-r7}
+ ldmfd sp!, {r4-r8, lr}
#endif
4: tst r2, #8
- stmneia r0!, {r1, r3}
+ stmiane ip!, {r1, r3}
tst r2, #4
- strne r1, [r0], #4
+ strne r1, [ip], #4
/*
* When we get here, we've got less than 4 bytes to zero. We
* may have an unaligned pointer as well.
*/
5: tst r2, #2
- strneb r1, [r0], #1
- strneb r1, [r0], #1
+ strbne r1, [ip], #1
+ strbne r1, [ip], #1
tst r2, #1
- strneb r1, [r0], #1
- mov pc, lr
+ strbne r1, [ip], #1
+ ret lr
+
+6: subs r2, r2, #4 @ 1 do we have enough
+ blt 5b @ 1 bytes to align with?
+ cmp r3, #2 @ 1
+ strblt r1, [ip], #1 @ 1
+ strble r1, [ip], #1 @ 1
+ strb r1, [ip], #1 @ 1
+ add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3))
+ b 1b
+ENDPROC(memset)
--
2.1.3
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