crypto: arm64/sha2-ce - yield NEON after every block of input

Avoid excessive scheduling delays under a preemptible kernel by
yielding the NEON after every block of input.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ard Biesheuvel 2018-04-30 18:18:22 +02:00 committed by Herbert Xu
parent 7df8d16475
commit d82f37ab5e
1 changed files with 26 additions and 11 deletions

View File

@ -79,30 +79,36 @@
*/
.text
ENTRY(sha2_ce_transform)
frame_push 3
mov x19, x0
mov x20, x1
mov x21, x2
/* load round constants */
adr_l x8, .Lsha2_rcon
0: adr_l x8, .Lsha2_rcon
ld1 { v0.4s- v3.4s}, [x8], #64
ld1 { v4.4s- v7.4s}, [x8], #64
ld1 { v8.4s-v11.4s}, [x8], #64
ld1 {v12.4s-v15.4s}, [x8]
/* load state */
ld1 {dgav.4s, dgbv.4s}, [x0]
ld1 {dgav.4s, dgbv.4s}, [x19]
/* load sha256_ce_state::finalize */
ldr_l w4, sha256_ce_offsetof_finalize, x4
ldr w4, [x0, x4]
ldr w4, [x19, x4]
/* load input */
0: ld1 {v16.4s-v19.4s}, [x1], #64
sub w2, w2, #1
1: ld1 {v16.4s-v19.4s}, [x20], #64
sub w21, w21, #1
CPU_LE( rev32 v16.16b, v16.16b )
CPU_LE( rev32 v17.16b, v17.16b )
CPU_LE( rev32 v18.16b, v18.16b )
CPU_LE( rev32 v19.16b, v19.16b )
1: add t0.4s, v16.4s, v0.4s
2: add t0.4s, v16.4s, v0.4s
mov dg0v.16b, dgav.16b
mov dg1v.16b, dgbv.16b
@ -131,16 +137,24 @@ CPU_LE( rev32 v19.16b, v19.16b )
add dgbv.4s, dgbv.4s, dg1v.4s
/* handled all input blocks? */
cbnz w2, 0b
cbz w21, 3f
if_will_cond_yield_neon
st1 {dgav.4s, dgbv.4s}, [x19]
do_cond_yield_neon
b 0b
endif_yield_neon
b 1b
/*
* Final block: add padding and total bit count.
* Skip if the input size was not a round multiple of the block size,
* the padding is handled by the C code in that case.
*/
cbz x4, 3f
3: cbz x4, 4f
ldr_l w4, sha256_ce_offsetof_count, x4
ldr x4, [x0, x4]
ldr x4, [x19, x4]
movi v17.2d, #0
mov x8, #0x80000000
movi v18.2d, #0
@ -149,9 +163,10 @@ CPU_LE( rev32 v19.16b, v19.16b )
mov x4, #0
mov v19.d[0], xzr
mov v19.d[1], x7
b 1b
b 2b
/* store new state */
3: st1 {dgav.4s, dgbv.4s}, [x0]
4: st1 {dgav.4s, dgbv.4s}, [x19]
frame_pop
ret
ENDPROC(sha2_ce_transform)