Skip to content

Commit

Permalink
ARM: 7626/1: arm/crypto: Make asm SHA-1 and AES code Thumb-2 compatible
Browse files Browse the repository at this point in the history 
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@linaro.org>
Tested-by: David McCullough <ucdevel@gmail.com> (ARM only)
Acked-by: David McCullough <ucdevel@gmail.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
  • Loading branch information
Dave Martin authored and Russell King committed Jan 13, 2013
1 parent 9931fac commit 638591c
Show file tree
Hide file tree
Showing 2 changed files with 29 additions and 59 deletions.
64 changes: 20 additions & 44 deletions arch/arm/crypto/aes-armv4.S
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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]
Expand All @@ -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
Expand All @@ -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
Expand Down
24 changes: 9 additions & 15 deletions arch/arm/crypto/sha1-armv4-large.S
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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}
Expand Down Expand Up @@ -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]
Expand Down Expand Up @@ -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

Expand Down Expand Up @@ -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
Expand All @@ -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@openssl.org>"
.align 2

0 comments on commit 638591c

Please sign in to comment.