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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2018-04-30 18:18:27 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-05-12 00:13:10 +0800 |
| commit | 4e530fba699f80b08bd2671885db456ec9e90260 (patch) | |
| tree | 58fac6a835353beb36d10f8ea6aff6379eff089e /arch/arm64/crypto | |
| parent | 7c50136a8aba8784f07fb66a950cc61a7f3d2ee3 (diff) | |
| download | lwn-4e530fba699f80b08bd2671885db456ec9e90260.tar.gz lwn-4e530fba699f80b08bd2671885db456ec9e90260.zip | |
crypto: arm64/crc32-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>
Diffstat (limited to 'arch/arm64/crypto')
| -rw-r--r-- | arch/arm64/crypto/crc32-ce-core.S | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/arch/arm64/crypto/crc32-ce-core.S b/arch/arm64/crypto/crc32-ce-core.S index 16ed3c7ebd37..8061bf0f9c66 100644 --- a/arch/arm64/crypto/crc32-ce-core.S +++ b/arch/arm64/crypto/crc32-ce-core.S @@ -100,9 +100,10 @@ dCONSTANT .req d0 qCONSTANT .req q0 - BUF .req x0 - LEN .req x1 - CRC .req x2 + BUF .req x19 + LEN .req x20 + CRC .req x21 + CONST .req x22 vzr .req v9 @@ -123,7 +124,14 @@ ENTRY(crc32_pmull_le) ENTRY(crc32c_pmull_le) adr_l x3, .Lcrc32c_constants -0: bic LEN, LEN, #15 +0: frame_push 4, 64 + + mov BUF, x0 + mov LEN, x1 + mov CRC, x2 + mov CONST, x3 + + bic LEN, LEN, #15 ld1 {v1.16b-v4.16b}, [BUF], #0x40 movi vzr.16b, #0 fmov dCONSTANT, CRC @@ -132,7 +140,7 @@ ENTRY(crc32c_pmull_le) cmp LEN, #0x40 b.lt less_64 - ldr qCONSTANT, [x3] + ldr qCONSTANT, [CONST] loop_64: /* 64 bytes Full cache line folding */ sub LEN, LEN, #0x40 @@ -162,10 +170,21 @@ loop_64: /* 64 bytes Full cache line folding */ eor v4.16b, v4.16b, v8.16b cmp LEN, #0x40 - b.ge loop_64 + b.lt less_64 + + if_will_cond_yield_neon + stp q1, q2, [sp, #.Lframe_local_offset] + stp q3, q4, [sp, #.Lframe_local_offset + 32] + do_cond_yield_neon + ldp q1, q2, [sp, #.Lframe_local_offset] + ldp q3, q4, [sp, #.Lframe_local_offset + 32] + ldr qCONSTANT, [CONST] + movi vzr.16b, #0 + endif_yield_neon + b loop_64 less_64: /* Folding cache line into 128bit */ - ldr qCONSTANT, [x3, #16] + ldr qCONSTANT, [CONST, #16] pmull2 v5.1q, v1.2d, vCONSTANT.2d pmull v1.1q, v1.1d, vCONSTANT.1d @@ -204,8 +223,8 @@ fold_64: eor v1.16b, v1.16b, v2.16b /* final 32-bit fold */ - ldr dCONSTANT, [x3, #32] - ldr d3, [x3, #40] + ldr dCONSTANT, [CONST, #32] + ldr d3, [CONST, #40] ext v2.16b, v1.16b, vzr.16b, #4 and v1.16b, v1.16b, v3.16b @@ -213,7 +232,7 @@ fold_64: eor v1.16b, v1.16b, v2.16b /* Finish up with the bit-reversed barrett reduction 64 ==> 32 bits */ - ldr qCONSTANT, [x3, #48] + ldr qCONSTANT, [CONST, #48] and v2.16b, v1.16b, v3.16b ext v2.16b, vzr.16b, v2.16b, #8 @@ -223,6 +242,7 @@ fold_64: eor v1.16b, v1.16b, v2.16b mov w0, v1.s[1] + frame_pop ret ENDPROC(crc32_pmull_le) ENDPROC(crc32c_pmull_le) |