[PATCH v5 21/23] crypto: arm64/sha512-ce - yield NEON after every block of input
From: Ard Biesheuvel <hidden>
Date: 2018-03-10 15:22:06
Also in:
linux-crypto, linux-rt-users
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Avoid excessive scheduling delays under a preemptible kernel by conditionally yielding the NEON after every block of input. Signed-off-by: Ard Biesheuvel <redacted> --- arch/arm64/crypto/sha512-ce-core.S | 27 +++++++++++++++----- 1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/crypto/sha512-ce-core.S b/arch/arm64/crypto/sha512-ce-core.S
index 7f3bca5c59a2..ce65e3abe4f2 100644
--- a/arch/arm64/crypto/sha512-ce-core.S
+++ b/arch/arm64/crypto/sha512-ce-core.S@@ -107,17 +107,23 @@ */ .text ENTRY(sha512_ce_transform) + frame_push 3 + + mov x19, x0 + mov x20, x1 + mov x21, x2 + /* load state */ - ld1 {v8.2d-v11.2d}, [x0] +0: ld1 {v8.2d-v11.2d}, [x19] /* load first 4 round constants */ adr_l x3, .Lsha512_rcon ld1 {v20.2d-v23.2d}, [x3], #64 /* load input */ -0: ld1 {v12.2d-v15.2d}, [x1], #64 - ld1 {v16.2d-v19.2d}, [x1], #64 - sub w2, w2, #1 +1: ld1 {v12.2d-v15.2d}, [x20], #64 + ld1 {v16.2d-v19.2d}, [x20], #64 + sub w21, w21, #1 CPU_LE( rev64 v12.16b, v12.16b ) CPU_LE( rev64 v13.16b, v13.16b )
@@ -196,9 +202,18 @@ CPU_LE( rev64 v19.16b, v19.16b ) add v11.2d, v11.2d, v3.2d /* handled all input blocks? */ - cbnz w2, 0b + cbz w21, 3f + + if_will_cond_yield_neon + st1 {v8.2d-v11.2d}, [x19] + do_cond_yield_neon + b 0b + endif_yield_neon + + b 1b /* store new state */ -3: st1 {v8.2d-v11.2d}, [x0] +3: st1 {v8.2d-v11.2d}, [x19] + frame_pop ret ENDPROC(sha512_ce_transform)
--
2.15.1