[PATCH] arm/crypto: Make asm SHA-1 and AES code Thumb-2 compatible
Dave Martin
dave.martin at linaro.org
Mon Nov 5 07:42:17 EST 2012
This patch fixes aes-armv4.S and sha1-armv4-large.S to work
natively in Thumb. This allows ARM/Thumb interworking workarounds
to be removed.
I also take the opportunity to convert some explicit assembler
directives for exported functions to the standard
ENTRY()/ENDPROC().
For the code itself:
* In sha1_block_data_order, use of TEQ with sp is deprecated in
ARMv7 and not supported in Thumb. For the branches back to
.L_00_15 and .L_40_59, the TEQ is converted to a CMP, under the
assumption that clobbering the C flag here will not cause
incorrect behaviour.
For the first branch back to .L_20_39_or_60_79 the C flag is
important, so sp is moved temporarily into another register so
that TEQ can be used for the comparison.
* In the AES code, most forms of register-indexed addressing with
shifts and rotates are not permitted for loads and stores in
Thumb, so the address calculation is done using a separate
instruction for the Thumb case.
The resulting code is unlikely to be optimally scheduled, but
it should not have a large impact given the overall size of the
code. I haven't run any benchmarks.
Signed-off-by: Dave Martin <dave.martin at linaro.org>
---
For now, I have built the code but not tested it. I'll consider the
patch an RFC until someone gives me a Tested-by (or failing that, when I
get around to testing it myself...)
Cheers
---Dave
arch/arm/crypto/aes-armv4.S | 64 +++++++++++------------------------
arch/arm/crypto/sha1-armv4-large.S | 24 +++++--------
2 files changed, 29 insertions(+), 59 deletions(-)
diff --git a/arch/arm/crypto/aes-armv4.S b/arch/arm/crypto/aes-armv4.S
index e59b1d5..19d6cd6 100644
--- a/arch/arm/crypto/aes-armv4.S
+++ b/arch/arm/crypto/aes-armv4.S
@@ -34,8 +34,9 @@
@ A little glue here to select the correct code below for the ARM CPU
@ that is being targetted.
+#include <linux/linkage.h>
+
.text
-.code 32
.type AES_Te,%object
.align 5
@@ -145,10 +146,8 @@ AES_Te:
@ void AES_encrypt(const unsigned char *in, unsigned char *out,
@ const AES_KEY *key) {
-.global AES_encrypt
-.type AES_encrypt,%function
.align 5
-AES_encrypt:
+ENTRY(AES_encrypt)
sub r3,pc,#8 @ AES_encrypt
stmdb sp!,{r1,r4-r12,lr}
mov r12,r0 @ inp
@@ -239,15 +238,8 @@ AES_encrypt:
strb r6,[r12,#14]
strb r3,[r12,#15]
#endif
-#if __ARM_ARCH__>=5
ldmia sp!,{r4-r12,pc}
-#else
- ldmia sp!,{r4-r12,lr}
- tst lr,#1
- moveq pc,lr @ be binary compatible with V4, yet
- .word 0xe12fff1e @ interoperable with Thumb ISA:-)
-#endif
-.size AES_encrypt,.-AES_encrypt
+ENDPROC(AES_encrypt)
.type _armv4_AES_encrypt,%function
.align 2
@@ -386,10 +378,8 @@ _armv4_AES_encrypt:
ldr pc,[sp],#4 @ pop and return
.size _armv4_AES_encrypt,.-_armv4_AES_encrypt
-.global private_AES_set_encrypt_key
-.type private_AES_set_encrypt_key,%function
.align 5
-private_AES_set_encrypt_key:
+ENTRY(private_AES_set_encrypt_key)
_armv4_AES_set_encrypt_key:
sub r3,pc,#8 @ AES_set_encrypt_key
teq r0,#0
@@ -658,15 +648,11 @@ _armv4_AES_set_encrypt_key:
.Ldone: mov r0,#0
ldmia sp!,{r4-r12,lr}
-.Labrt: tst lr,#1
- moveq pc,lr @ be binary compatible with V4, yet
- .word 0xe12fff1e @ interoperable with Thumb ISA:-)
-.size private_AES_set_encrypt_key,.-private_AES_set_encrypt_key
+.Labrt: mov pc,lr
+ENDPROC(private_AES_set_encrypt_key)
-.global private_AES_set_decrypt_key
-.type private_AES_set_decrypt_key,%function
.align 5
-private_AES_set_decrypt_key:
+ENTRY(private_AES_set_decrypt_key)
str lr,[sp,#-4]! @ push lr
#if 0
@ kernel does both of these in setkey so optimise this bit out by
@@ -748,15 +734,8 @@ private_AES_set_decrypt_key:
bne .Lmix
mov r0,#0
-#if __ARM_ARCH__>=5
ldmia sp!,{r4-r12,pc}
-#else
- ldmia sp!,{r4-r12,lr}
- tst lr,#1
- moveq pc,lr @ be binary compatible with V4, yet
- .word 0xe12fff1e @ interoperable with Thumb ISA:-)
-#endif
-.size private_AES_set_decrypt_key,.-private_AES_set_decrypt_key
+ENDPROC(private_AES_set_decrypt_key)
.type AES_Td,%object
.align 5
@@ -862,10 +841,8 @@ AES_Td:
@ void AES_decrypt(const unsigned char *in, unsigned char *out,
@ const AES_KEY *key) {
-.global AES_decrypt
-.type AES_decrypt,%function
.align 5
-AES_decrypt:
+ENTRY(AES_decrypt)
sub r3,pc,#8 @ AES_decrypt
stmdb sp!,{r1,r4-r12,lr}
mov r12,r0 @ inp
@@ -956,15 +933,8 @@ AES_decrypt:
strb r6,[r12,#14]
strb r3,[r12,#15]
#endif
-#if __ARM_ARCH__>=5
ldmia sp!,{r4-r12,pc}
-#else
- ldmia sp!,{r4-r12,lr}
- tst lr,#1
- moveq pc,lr @ be binary compatible with V4, yet
- .word 0xe12fff1e @ interoperable with Thumb ISA:-)
-#endif
-.size AES_decrypt,.-AES_decrypt
+ENDPROC(AES_decrypt)
.type _armv4_AES_decrypt,%function
.align 2
@@ -1064,7 +1034,9 @@ _armv4_AES_decrypt:
and r9,lr,r1,lsr#8
ldrb r7,[r10,r7] @ Td4[s1>>0]
- ldrb r1,[r10,r1,lsr#24] @ Td4[s1>>24]
+ ARM( ldrb r1,[r10,r1,lsr#24] ) @ Td4[s1>>24]
+ THUMB( add r1,r10,r1,lsr#24 ) @ Td4[s1>>24]
+ THUMB( ldrb r1,[r1] )
ldrb r8,[r10,r8] @ Td4[s1>>16]
eor r0,r7,r0,lsl#24
ldrb r9,[r10,r9] @ Td4[s1>>8]
@@ -1077,7 +1049,9 @@ _armv4_AES_decrypt:
ldrb r8,[r10,r8] @ Td4[s2>>0]
and r9,lr,r2,lsr#16
- ldrb r2,[r10,r2,lsr#24] @ Td4[s2>>24]
+ ARM( ldrb r2,[r10,r2,lsr#24] ) @ Td4[s2>>24]
+ THUMB( add r2,r10,r2,lsr#24 ) @ Td4[s2>>24]
+ THUMB( ldrb r2,[r2] )
eor r0,r0,r7,lsl#8
ldrb r9,[r10,r9] @ Td4[s2>>16]
eor r1,r8,r1,lsl#16
@@ -1090,7 +1064,9 @@ _armv4_AES_decrypt:
and r9,lr,r3 @ i2
ldrb r9,[r10,r9] @ Td4[s3>>0]
- ldrb r3,[r10,r3,lsr#24] @ Td4[s3>>24]
+ ARM( ldrb r3,[r10,r3,lsr#24] ) @ Td4[s3>>24]
+ THUMB( add r3,r10,r3,lsr#24 ) @ Td4[s3>>24]
+ THUMB( ldrb r3,[r3] )
eor r0,r0,r7,lsl#16
ldr r7,[r11,#0]
eor r1,r1,r8,lsl#8
diff --git a/arch/arm/crypto/sha1-armv4-large.S b/arch/arm/crypto/sha1-armv4-large.S
index 7050ab1..92c6eed 100644
--- a/arch/arm/crypto/sha1-armv4-large.S
+++ b/arch/arm/crypto/sha1-armv4-large.S
@@ -51,13 +51,12 @@
@ Profiler-assisted and platform-specific optimization resulted in 10%
@ improvement on Cortex A8 core and 12.2 cycles per byte.
-.text
+#include <linux/linkage.h>
-.global sha1_block_data_order
-.type sha1_block_data_order,%function
+.text
.align 2
-sha1_block_data_order:
+ENTRY(sha1_block_data_order)
stmdb sp!,{r4-r12,lr}
add r2,r1,r2,lsl#6 @ r2 to point at the end of r1
ldmia r0,{r3,r4,r5,r6,r7}
@@ -194,7 +193,7 @@ sha1_block_data_order:
eor r10,r10,r7,ror#2 @ F_00_19(B,C,D)
str r9,[r14,#-4]!
add r3,r3,r10 @ E+=F_00_19(B,C,D)
- teq r14,sp
+ cmp r14,sp
bne .L_00_15 @ [((11+4)*5+2)*3]
#if __ARM_ARCH__<7
ldrb r10,[r1,#2]
@@ -374,7 +373,9 @@ sha1_block_data_order:
@ F_xx_xx
add r3,r3,r9 @ E+=X[i]
add r3,r3,r10 @ E+=F_20_39(B,C,D)
- teq r14,sp @ preserve carry
+ ARM( teq r14,sp ) @ preserve carry
+ THUMB( mov r11,sp )
+ THUMB( teq r14,r11 ) @ preserve carry
bne .L_20_39_or_60_79 @ [+((12+3)*5+2)*4]
bcs .L_done @ [+((12+3)*5+2)*4], spare 300 bytes
@@ -466,7 +467,7 @@ sha1_block_data_order:
add r3,r3,r9 @ E+=X[i]
add r3,r3,r10 @ E+=F_40_59(B,C,D)
add r3,r3,r11,ror#2
- teq r14,sp
+ cmp r14,sp
bne .L_40_59 @ [+((12+5)*5+2)*4]
ldr r8,.LK_60_79
@@ -485,19 +486,12 @@ sha1_block_data_order:
teq r1,r2
bne .Lloop @ [+18], total 1307
-#if __ARM_ARCH__>=5
ldmia sp!,{r4-r12,pc}
-#else
- ldmia sp!,{r4-r12,lr}
- tst lr,#1
- moveq pc,lr @ be binary compatible with V4, yet
- .word 0xe12fff1e @ interoperable with Thumb ISA:-)
-#endif
.align 2
.LK_00_19: .word 0x5a827999
.LK_20_39: .word 0x6ed9eba1
.LK_40_59: .word 0x8f1bbcdc
.LK_60_79: .word 0xca62c1d6
-.size sha1_block_data_order,.-sha1_block_data_order
+ENDPROC(sha1_block_data_order)
.asciz "SHA1 block transform for ARMv4, CRYPTOGAMS by <appro at openssl.org>"
.align 2
--
1.7.4.1
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