From: Ard Biesheuvel <ardb@xxxxxxxxxx>
The only remaining user of the fallback implementation of 64x64
polynomial multiplication using 8x8 PMULL instructions is the final
reduction from a 16 byte vector to a 16-bit CRC.
The fallback code is complicated and messy, and this reduction has
little impact on the overall performance, so instead, let's calculate
the final CRC by passing the 16 byte vector to the generic CRC-T10DIF
implementation when running the fallback version.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/arm64/crypto/crct10dif-ce-core.S | 244 +++++---------------
arch/arm64/crypto/crct10dif-ce-glue.c | 18 +-
2 files changed, 68 insertions(+), 194 deletions(-)
diff --git a/arch/arm64/crypto/crct10dif-ce-core.S b/arch/arm64/crypto/crct10dif-ce-core.S
index d2acaa2b5a01..87dd6d46224d 100644
--- a/arch/arm64/crypto/crct10dif-ce-core.S
+++ b/arch/arm64/crypto/crct10dif-ce-core.S
@@ -74,137 +74,18 @@
init_crc .req w0
buf .req x1
len .req x2
- fold_consts_ptr .req x3
+ fold_consts_ptr .req x5
fold_consts .req v10
- ad .req v14
-
- k00_16 .req v15
- k32_48 .req v16
-
t3 .req v17
t4 .req v18
t5 .req v19
t6 .req v20
t7 .req v21
t8 .req v22
- t9 .req v23
-
- perm1 .req v24
- perm2 .req v25
- perm3 .req v26
- perm4 .req v27
-
- bd1 .req v28
- bd2 .req v29
- bd3 .req v30
- bd4 .req v31
-
- .macro __pmull_init_p64
- .endm
- .macro __pmull_pre_p64, bd
- .endm
-
- .macro __pmull_init_p8
- // k00_16 := 0x0000000000000000_000000000000ffff
- // k32_48 := 0x00000000ffffffff_0000ffffffffffff
- movi k32_48.2d, #0xffffffff
- mov k32_48.h[2], k32_48.h[0]
- ushr k00_16.2d, k32_48.2d, #32
-
- // prepare the permutation vectors
- mov_q x5, 0x080f0e0d0c0b0a09
- movi perm4.8b, #8
- dup perm1.2d, x5
- eor perm1.16b, perm1.16b, perm4.16b
- ushr perm2.2d, perm1.2d, #8
- ushr perm3.2d, perm1.2d, #16
- ushr perm4.2d, perm1.2d, #24
- sli perm2.2d, perm1.2d, #56
- sli perm3.2d, perm1.2d, #48
- sli perm4.2d, perm1.2d, #40
-
- // Compose { 0,0,0,0, 8,8,8,8, 1,1,1,1, 9,9,9,9 }
- movi bd1.4h, #8, lsl #8
- orr bd1.2s, #1, lsl #16
- orr bd1.2s, #1, lsl #24
- zip1 bd1.16b, bd1.16b, bd1.16b
- zip1 bd1.16b, bd1.16b, bd1.16b
- .endm
-
- .macro __pmull_pre_p8, bd
- tbl bd1.16b, {\bd\().16b}, perm1.16b
- tbl bd2.16b, {\bd\().16b}, perm2.16b
- tbl bd3.16b, {\bd\().16b}, perm3.16b
- tbl bd4.16b, {\bd\().16b}, perm4.16b
- .endm
-
-SYM_FUNC_START_LOCAL(__pmull_p8_core)
-.L__pmull_p8_core:
- ext t4.8b, ad.8b, ad.8b, #1 // A1
- ext t5.8b, ad.8b, ad.8b, #2 // A2
- ext t6.8b, ad.8b, ad.8b, #3 // A3
-
- pmull t4.8h, t4.8b, fold_consts.8b // F = A1*B
- pmull t8.8h, ad.8b, bd1.8b // E = A*B1
- pmull t5.8h, t5.8b, fold_consts.8b // H = A2*B
- pmull t7.8h, ad.8b, bd2.8b // G = A*B2
- pmull t6.8h, t6.8b, fold_consts.8b // J = A3*B
- pmull t9.8h, ad.8b, bd3.8b // I = A*B3
- pmull t3.8h, ad.8b, bd4.8b // K = A*B4
- b 0f
-
-.L__pmull_p8_core2:
- tbl t4.16b, {ad.16b}, perm1.16b // A1
- tbl t5.16b, {ad.16b}, perm2.16b // A2
- tbl t6.16b, {ad.16b}, perm3.16b // A3
-
- pmull2 t4.8h, t4.16b, fold_consts.16b // F = A1*B
- pmull2 t8.8h, ad.16b, bd1.16b // E = A*B1
- pmull2 t5.8h, t5.16b, fold_consts.16b // H = A2*B
- pmull2 t7.8h, ad.16b, bd2.16b // G = A*B2
- pmull2 t6.8h, t6.16b, fold_consts.16b // J = A3*B
- pmull2 t9.8h, ad.16b, bd3.16b // I = A*B3
- pmull2 t3.8h, ad.16b, bd4.16b // K = A*B4
-
-0: eor t4.16b, t4.16b, t8.16b // L = E + F
- eor t5.16b, t5.16b, t7.16b // M = G + H
- eor t6.16b, t6.16b, t9.16b // N = I + J
-
- uzp1 t8.2d, t4.2d, t5.2d
- uzp2 t4.2d, t4.2d, t5.2d
- uzp1 t7.2d, t6.2d, t3.2d
- uzp2 t6.2d, t6.2d, t3.2d
-
- // t4 = (L) (P0 + P1) << 8
- // t5 = (M) (P2 + P3) << 16
- eor t8.16b, t8.16b, t4.16b
- and t4.16b, t4.16b, k32_48.16b
-
- // t6 = (N) (P4 + P5) << 24
- // t7 = (K) (P6 + P7) << 32
- eor t7.16b, t7.16b, t6.16b
- and t6.16b, t6.16b, k00_16.16b
-
- eor t8.16b, t8.16b, t4.16b
- eor t7.16b, t7.16b, t6.16b
-
- zip2 t5.2d, t8.2d, t4.2d
- zip1 t4.2d, t8.2d, t4.2d
- zip2 t3.2d, t7.2d, t6.2d
- zip1 t6.2d, t7.2d, t6.2d
-
- ext t4.16b, t4.16b, t4.16b, #15
- ext t5.16b, t5.16b, t5.16b, #14
- ext t6.16b, t6.16b, t6.16b, #13
- ext t3.16b, t3.16b, t3.16b, #12
-
- eor t4.16b, t4.16b, t5.16b
- eor t6.16b, t6.16b, t3.16b
- ret
-SYM_FUNC_END(__pmull_p8_core)
+ perm .req v27
.macro pmull16x64_p64, a16, b64, c64
pmull2 \c64\().1q, \a16\().2d, \b64\().2d
@@ -266,7 +147,7 @@ SYM_FUNC_END(__pmull_p8_core)
*/
.macro pmull16x64_p8, a16, b64, c64
ext t7.16b, \b64\().16b, \b64\().16b, #1
- tbl t5.16b, {\a16\().16b}, bd1.16b
+ tbl t5.16b, {\a16\().16b}, perm.16b
uzp1 t7.16b, \b64\().16b, t7.16b
bl __pmull_p8_16x64
ext \b64\().16b, t4.16b, t4.16b, #15
@@ -292,22 +173,6 @@ SYM_FUNC_START_LOCAL(__pmull_p8_16x64)
ret
SYM_FUNC_END(__pmull_p8_16x64)
- .macro __pmull_p8, rq, ad, bd, i
- .ifnc \bd, fold_consts
- .err
- .endif
- mov ad.16b, \ad\().16b
- .ifb \i
- pmull \rq\().8h, \ad\().8b, \bd\().8b // D = A*B
- .else
- pmull2 \rq\().8h, \ad\().16b, \bd\().16b // D = A*B
- .endif
-
- bl .L__pmull_p8_core\i
-
- eor \rq\().16b, \rq\().16b, t4.16b
- eor \rq\().16b, \rq\().16b, t6.16b
- .endm
// Fold reg1, reg2 into the next 32 data bytes, storing the result back
// into reg1, reg2.
@@ -340,16 +205,7 @@ CPU_LE( ext v12.16b, v12.16b, v12.16b, #8 )
eor \dst_reg\().16b, \dst_reg\().16b, \src_reg\().16b
.endm
- .macro __pmull_p64, rd, rn, rm, n
- .ifb \n
- pmull \rd\().1q, \rn\().1d, \rm\().1d
- .else
- pmull2 \rd\().1q, \rn\().2d, \rm\().2d
- .endif
- .endm
-
.macro crc_t10dif_pmull, p
- __pmull_init_\p
// For sizes less than 256 bytes, we can't fold 128 bytes at a time.
cmp len, #256
@@ -479,47 +335,7 @@ CPU_LE( ext v0.16b, v0.16b, v0.16b, #8 )
pmull16x64_\p fold_consts, v3, v0
eor v7.16b, v3.16b, v0.16b
eor v7.16b, v7.16b, v2.16b
-
-.Lreduce_final_16_bytes_\@:
- // Reduce the 128-bit value M(x), stored in v7, to the final 16-bit CRC.
-
- movi v2.16b, #0 // init zero register
-
- // Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'.
- ld1 {fold_consts.2d}, [fold_consts_ptr], #16
- __pmull_pre_\p fold_consts
-
- // Fold the high 64 bits into the low 64 bits, while also multiplying by
- // x^64. This produces a 128-bit value congruent to x^64 * M(x) and
- // whose low 48 bits are 0.
- ext v0.16b, v2.16b, v7.16b, #8
- __pmull_\p v7, v7, fold_consts, 2 // high bits * x^48 * (x^80 mod G(x))
- eor v0.16b, v0.16b, v7.16b // + low bits * x^64
-
- // Fold the high 32 bits into the low 96 bits. This produces a 96-bit
- // value congruent to x^64 * M(x) and whose low 48 bits are 0.
- ext v1.16b, v0.16b, v2.16b, #12 // extract high 32 bits
- mov v0.s[3], v2.s[0] // zero high 32 bits
- __pmull_\p v1, v1, fold_consts // high 32 bits * x^48 * (x^48 mod G(x))
- eor v0.16b, v0.16b, v1.16b // + low bits
-
- // Load G(x) and floor(x^48 / G(x)).
- ld1 {fold_consts.2d}, [fold_consts_ptr]
- __pmull_pre_\p fold_consts
-
- // Use Barrett reduction to compute the final CRC value.
- __pmull_\p v1, v0, fold_consts, 2 // high 32 bits * floor(x^48 / G(x))
- ushr v1.2d, v1.2d, #32 // /= x^32
- __pmull_\p v1, v1, fold_consts // *= G(x)
- ushr v0.2d, v0.2d, #48
- eor v0.16b, v0.16b, v1.16b // + low 16 nonzero bits
- // Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of v0.
-
- umov w0, v0.h[0]
- .ifc \p, p8
- frame_pop
- .endif
- ret
+ b .Lreduce_final_16_bytes_\@
.Lless_than_256_bytes_\@:
// Checksumming a buffer of length 16...255 bytes
@@ -545,6 +361,8 @@ CPU_LE( ext v7.16b, v7.16b, v7.16b, #8 )
b.ge .Lfold_16_bytes_loop_\@ // 32 <= len <= 255
add len, len, #16
b .Lhandle_partial_segment_\@ // 17 <= len <= 31
+
+.Lreduce_final_16_bytes_\@:
.endm
//
@@ -554,7 +372,22 @@ CPU_LE( ext v7.16b, v7.16b, v7.16b, #8 )
//
SYM_FUNC_START(crc_t10dif_pmull_p8)
frame_push 1
+
+ // Compose { 0,0,0,0, 8,8,8,8, 1,1,1,1, 9,9,9,9 }
+ movi perm.4h, #8, lsl #8
+ orr perm.2s, #1, lsl #16
+ orr perm.2s, #1, lsl #24
+ zip1 perm.16b, perm.16b, perm.16b
+ zip1 perm.16b, perm.16b, perm.16b
+
crc_t10dif_pmull p8
+
+CPU_LE( rev64 v7.16b, v7.16b )
+CPU_LE( ext v7.16b, v7.16b, v7.16b, #8 )
+ str q7, [x3]
+
+ frame_pop
+ ret
SYM_FUNC_END(crc_t10dif_pmull_p8)
.align 5
@@ -565,6 +398,41 @@ SYM_FUNC_END(crc_t10dif_pmull_p8)
//
SYM_FUNC_START(crc_t10dif_pmull_p64)
crc_t10dif_pmull p64
+
+ // Reduce the 128-bit value M(x), stored in v7, to the final 16-bit CRC.
+
+ movi v2.16b, #0 // init zero register
+
+ // Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'.
+ ld1 {fold_consts.2d}, [fold_consts_ptr], #16
+
+ // Fold the high 64 bits into the low 64 bits, while also multiplying by
+ // x^64. This produces a 128-bit value congruent to x^64 * M(x) and
+ // whose low 48 bits are 0.
+ ext v0.16b, v2.16b, v7.16b, #8
+ pmull2 v7.1q, v7.2d, fold_consts.2d // high bits * x^48 * (x^80 mod G(x))
+ eor v0.16b, v0.16b, v7.16b // + low bits * x^64
+
+ // Fold the high 32 bits into the low 96 bits. This produces a 96-bit
+ // value congruent to x^64 * M(x) and whose low 48 bits are 0.
+ ext v1.16b, v0.16b, v2.16b, #12 // extract high 32 bits
+ mov v0.s[3], v2.s[0] // zero high 32 bits
+ pmull v1.1q, v1.1d, fold_consts.1d // high 32 bits * x^48 * (x^48 mod G(x))
+ eor v0.16b, v0.16b, v1.16b // + low bits
+
+ // Load G(x) and floor(x^48 / G(x)).
+ ld1 {fold_consts.2d}, [fold_consts_ptr]
+
+ // Use Barrett reduction to compute the final CRC value.
+ pmull2 v1.1q, v0.2d, fold_consts.2d // high 32 bits * floor(x^48 / G(x))
+ ushr v1.2d, v1.2d, #32 // /= x^32
+ pmull v1.1q, v1.1d, fold_consts.1d // *= G(x)
+ ushr v0.2d, v0.2d, #48
+ eor v0.16b, v0.16b, v1.16b // + low 16 nonzero bits
+ // Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of v0.
+
+ umov w0, v0.h[0]
+ ret
SYM_FUNC_END(crc_t10dif_pmull_p64)
.section ".rodata", "a"
diff --git a/arch/arm64/crypto/crct10dif-ce-glue.c b/arch/arm64/crypto/crct10dif-ce-glue.c
index 7b05094a0480..08bcbd884395 100644
--- a/arch/arm64/crypto/crct10dif-ce-glue.c
+++ b/arch/arm64/crypto/crct10dif-ce-glue.c
@@ -20,7 +20,8 @@
#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
-asmlinkage u16 crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len);
+asmlinkage void crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len,
+ u8 out[16]);
asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
static int crct10dif_init(struct shash_desc *desc)
@@ -34,16 +35,21 @@ static int crct10dif_init(struct shash_desc *desc)
static int crct10dif_update_pmull_p8(struct shash_desc *desc, const u8 *data,
unsigned int length)
{
- u16 *crc = shash_desc_ctx(desc);
+ u16 *crcp = shash_desc_ctx(desc);
+ u16 crc = *crcp;
+ u8 buf[16];
- if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
+ if (length > CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
kernel_neon_begin();
- *crc = crc_t10dif_pmull_p8(*crc, data, length);
+ crc_t10dif_pmull_p8(crc, data, length, buf);
kernel_neon_end();
- } else {
- *crc = crc_t10dif_generic(*crc, data, length);
+
+ crc = 0;
+ data = buf;
+ length = sizeof(buf);
}
+ *crcp = crc_t10dif_generic(crc, data, length);
return 0;
}
--
2.47.0.199.ga7371fff76-goog
