[PATCH v4 19/20] crypto: arm64/crct10dif-ce - yield NEON after every block of input
From: Ard Biesheuvel <hidden>
Date: 2017-12-26 10:31:39
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Avoid excessive scheduling delays under a preemptible kernel by yielding the NEON after every block of input. Signed-off-by: Ard Biesheuvel <redacted> --- arch/arm64/crypto/crct10dif-ce-core.S | 32 +++++++++++++++++--- 1 file changed, 28 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/crypto/crct10dif-ce-core.S b/arch/arm64/crypto/crct10dif-ce-core.S
index d5b5a8c038c8..5bce7833ca5f 100644
--- a/arch/arm64/crypto/crct10dif-ce-core.S
+++ b/arch/arm64/crypto/crct10dif-ce-core.S@@ -74,13 +74,19 @@ .text .cpu generic+crypto - arg1_low32 .req w0 - arg2 .req x1 - arg3 .req x2 + arg1_low32 .req w19 + arg2 .req x20 + arg3 .req x21 vzr .req v13 ENTRY(crc_t10dif_pmull) + frame_push 3, 128 + + mov arg1_low32, w0 + mov arg2, x1 + mov arg3, x2 + movi vzr.16b, #0 // init zero register // adjust the 16-bit initial_crc value, scale it to 32 bits
@@ -175,8 +181,25 @@ CPU_LE( ext v12.16b, v12.16b, v12.16b, #8 ) subs arg3, arg3, #128 // check if there is another 64B in the buffer to be able to fold - b.ge _fold_64_B_loop + b.lt _fold_64_B_end + + if_will_cond_yield_neon + stp q0, q1, [sp, #.Lframe_local_offset] + stp q2, q3, [sp, #.Lframe_local_offset + 32] + stp q4, q5, [sp, #.Lframe_local_offset + 64] + stp q6, q7, [sp, #.Lframe_local_offset + 96] + do_cond_yield_neon + ldp q0, q1, [sp, #.Lframe_local_offset] + ldp q2, q3, [sp, #.Lframe_local_offset + 32] + ldp q4, q5, [sp, #.Lframe_local_offset + 64] + ldp q6, q7, [sp, #.Lframe_local_offset + 96] + ldr q10, rk3 + movi vzr.16b, #0 // init zero register + endif_yield_neon + + b _fold_64_B_loop +_fold_64_B_end: // at this point, the buffer pointer is pointing at the last y Bytes // of the buffer the 64B of folded data is in 4 of the vector // registers: v0, v1, v2, v3
@@ -304,6 +327,7 @@ _barrett: _cleanup: // scale the result back to 16 bits lsr x0, x0, #16 + frame_pop ret _less_than_128:
--
2.11.0