[PATCH v2 5/6] crypto: arm/crct10dif - Macroify PMULL asm code
Ard Biesheuvel
ardb+git at google.com
Tue Nov 5 08:09:05 PST 2024
From: Ard Biesheuvel <ardb at kernel.org>
To allow an alternative version to be created of the PMULL based
CRC-T10DIF algorithm, turn the bulk of it into a macro, except for the
final reduction, which will only be used by the existing version.
Reviewed-by: Eric Biggers <ebiggers at google.com>
Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
---
arch/arm/crypto/crct10dif-ce-core.S | 154 ++++++++++----------
arch/arm/crypto/crct10dif-ce-glue.c | 10 +-
2 files changed, 83 insertions(+), 81 deletions(-)
diff --git a/arch/arm/crypto/crct10dif-ce-core.S b/arch/arm/crypto/crct10dif-ce-core.S
index 4dac32e020de..6b72167574b2 100644
--- a/arch/arm/crypto/crct10dif-ce-core.S
+++ b/arch/arm/crypto/crct10dif-ce-core.S
@@ -112,48 +112,42 @@
FOLD_CONST_L .req q10l
FOLD_CONST_H .req q10h
+ .macro pmull16x64_p64, v16, v64
+ vmull.p64 q11, \v64\()l, \v16\()_L
+ vmull.p64 \v64, \v64\()h, \v16\()_H
+ veor \v64, \v64, q11
+ .endm
+
// Fold reg1, reg2 into the next 32 data bytes, storing the result back
// into reg1, reg2.
- .macro fold_32_bytes, reg1, reg2
- vld1.64 {q11-q12}, [buf]!
+ .macro fold_32_bytes, reg1, reg2, p
+ vld1.64 {q8-q9}, [buf]!
- vmull.p64 q8, \reg1\()h, FOLD_CONST_H
- vmull.p64 \reg1, \reg1\()l, FOLD_CONST_L
- vmull.p64 q9, \reg2\()h, FOLD_CONST_H
- vmull.p64 \reg2, \reg2\()l, FOLD_CONST_L
+ pmull16x64_\p FOLD_CONST, \reg1
+ pmull16x64_\p FOLD_CONST, \reg2
-CPU_LE( vrev64.8 q11, q11 )
-CPU_LE( vrev64.8 q12, q12 )
- vswp q11l, q11h
- vswp q12l, q12h
+CPU_LE( vrev64.8 q8, q8 )
+CPU_LE( vrev64.8 q9, q9 )
+ vswp q8l, q8h
+ vswp q9l, q9h
veor.8 \reg1, \reg1, q8
veor.8 \reg2, \reg2, q9
- veor.8 \reg1, \reg1, q11
- veor.8 \reg2, \reg2, q12
.endm
// Fold src_reg into dst_reg, optionally loading the next fold constants
- .macro fold_16_bytes, src_reg, dst_reg, load_next_consts
- vmull.p64 q8, \src_reg\()l, FOLD_CONST_L
- vmull.p64 \src_reg, \src_reg\()h, FOLD_CONST_H
+ .macro fold_16_bytes, src_reg, dst_reg, p, load_next_consts
+ pmull16x64_\p FOLD_CONST, \src_reg
.ifnb \load_next_consts
vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
.endif
- veor.8 \dst_reg, \dst_reg, q8
veor.8 \dst_reg, \dst_reg, \src_reg
.endm
-//
-// u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
-//
-// Assumes len >= 16.
-//
-ENTRY(crc_t10dif_pmull)
-
+ .macro crct10dif, p
// For sizes less than 256 bytes, we can't fold 128 bytes at a time.
cmp len, #256
- blt .Lless_than_256_bytes
+ blt .Lless_than_256_bytes\@
mov_l fold_consts_ptr, .Lfold_across_128_bytes_consts
@@ -194,27 +188,27 @@ CPU_LE( vrev64.8 q7, q7 )
// While >= 128 data bytes remain (not counting q0-q7), fold the 128
// bytes q0-q7 into them, storing the result back into q0-q7.
-.Lfold_128_bytes_loop:
- fold_32_bytes q0, q1
- fold_32_bytes q2, q3
- fold_32_bytes q4, q5
- fold_32_bytes q6, q7
+.Lfold_128_bytes_loop\@:
+ fold_32_bytes q0, q1, \p
+ fold_32_bytes q2, q3, \p
+ fold_32_bytes q4, q5, \p
+ fold_32_bytes q6, q7, \p
subs len, len, #128
- bge .Lfold_128_bytes_loop
+ bge .Lfold_128_bytes_loop\@
// Now fold the 112 bytes in q0-q6 into the 16 bytes in q7.
// Fold across 64 bytes.
vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
- fold_16_bytes q0, q4
- fold_16_bytes q1, q5
- fold_16_bytes q2, q6
- fold_16_bytes q3, q7, 1
+ fold_16_bytes q0, q4, \p
+ fold_16_bytes q1, q5, \p
+ fold_16_bytes q2, q6, \p
+ fold_16_bytes q3, q7, \p, 1
// Fold across 32 bytes.
- fold_16_bytes q4, q6
- fold_16_bytes q5, q7, 1
+ fold_16_bytes q4, q6, \p
+ fold_16_bytes q5, q7, \p, 1
// Fold across 16 bytes.
- fold_16_bytes q6, q7
+ fold_16_bytes q6, q7, \p
// Add 128 to get the correct number of data bytes remaining in 0...127
// (not counting q7), following the previous extra subtraction by 128.
@@ -224,25 +218,23 @@ CPU_LE( vrev64.8 q7, q7 )
// While >= 16 data bytes remain (not counting q7), fold the 16 bytes q7
// into them, storing the result back into q7.
- blt .Lfold_16_bytes_loop_done
-.Lfold_16_bytes_loop:
- vmull.p64 q8, q7l, FOLD_CONST_L
- vmull.p64 q7, q7h, FOLD_CONST_H
- veor.8 q7, q7, q8
+ blt .Lfold_16_bytes_loop_done\@
+.Lfold_16_bytes_loop\@:
+ pmull16x64_\p FOLD_CONST, q7
vld1.64 {q0}, [buf]!
CPU_LE( vrev64.8 q0, q0 )
vswp q0l, q0h
veor.8 q7, q7, q0
subs len, len, #16
- bge .Lfold_16_bytes_loop
+ bge .Lfold_16_bytes_loop\@
-.Lfold_16_bytes_loop_done:
+.Lfold_16_bytes_loop_done\@:
// Add 16 to get the correct number of data bytes remaining in 0...15
// (not counting q7), following the previous extra subtraction by 16.
adds len, len, #16
- beq .Lreduce_final_16_bytes
+ beq .Lreduce_final_16_bytes\@
-.Lhandle_partial_segment:
+.Lhandle_partial_segment\@:
// Reduce the last '16 + len' bytes where 1 <= len <= 15 and the first
// 16 bytes are in q7 and the rest are the remaining data in 'buf'. To
// do this without needing a fold constant for each possible 'len',
@@ -277,12 +269,46 @@ CPU_LE( vrev64.8 q0, q0 )
vbsl.8 q2, q1, q0
// Fold the first chunk into the second chunk, storing the result in q7.
- vmull.p64 q0, q3l, FOLD_CONST_L
- vmull.p64 q7, q3h, FOLD_CONST_H
- veor.8 q7, q7, q0
- veor.8 q7, q7, q2
+ pmull16x64_\p FOLD_CONST, q3
+ veor.8 q7, q3, q2
+ b .Lreduce_final_16_bytes\@
+
+.Lless_than_256_bytes\@:
+ // Checksumming a buffer of length 16...255 bytes
+
+ mov_l fold_consts_ptr, .Lfold_across_16_bytes_consts
+
+ // Load the first 16 data bytes.
+ vld1.64 {q7}, [buf]!
+CPU_LE( vrev64.8 q7, q7 )
+ vswp q7l, q7h
+
+ // XOR the first 16 data *bits* with the initial CRC value.
+ vmov.i8 q0h, #0
+ vmov.u16 q0h[3], init_crc
+ veor.8 q7h, q7h, q0h
+
+ // Load the fold-across-16-bytes constants.
+ vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
+
+ cmp len, #16
+ beq .Lreduce_final_16_bytes\@ // len == 16
+ subs len, len, #32
+ addlt len, len, #16
+ blt .Lhandle_partial_segment\@ // 17 <= len <= 31
+ b .Lfold_16_bytes_loop\@ // 32 <= len <= 255
+
+.Lreduce_final_16_bytes\@:
+ .endm
+
+//
+// u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
+//
+// Assumes len >= 16.
+//
+ENTRY(crc_t10dif_pmull64)
+ crct10dif p64
-.Lreduce_final_16_bytes:
// Reduce the 128-bit value M(x), stored in q7, to the final 16-bit CRC.
// Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'.
@@ -316,31 +342,7 @@ CPU_LE( vrev64.8 q0, q0 )
vmov.u16 r0, q0l[0]
bx lr
-.Lless_than_256_bytes:
- // Checksumming a buffer of length 16...255 bytes
-
- mov_l fold_consts_ptr, .Lfold_across_16_bytes_consts
-
- // Load the first 16 data bytes.
- vld1.64 {q7}, [buf]!
-CPU_LE( vrev64.8 q7, q7 )
- vswp q7l, q7h
-
- // XOR the first 16 data *bits* with the initial CRC value.
- vmov.i8 q0h, #0
- vmov.u16 q0h[3], init_crc
- veor.8 q7h, q7h, q0h
-
- // Load the fold-across-16-bytes constants.
- vld1.64 {FOLD_CONSTS}, [fold_consts_ptr, :128]!
-
- cmp len, #16
- beq .Lreduce_final_16_bytes // len == 16
- subs len, len, #32
- addlt len, len, #16
- blt .Lhandle_partial_segment // 17 <= len <= 31
- b .Lfold_16_bytes_loop // 32 <= len <= 255
-ENDPROC(crc_t10dif_pmull)
+ENDPROC(crc_t10dif_pmull64)
.section ".rodata", "a"
.align 4
diff --git a/arch/arm/crypto/crct10dif-ce-glue.c b/arch/arm/crypto/crct10dif-ce-glue.c
index 79f3b204d8c0..60aa79c2fcdb 100644
--- a/arch/arm/crypto/crct10dif-ce-glue.c
+++ b/arch/arm/crypto/crct10dif-ce-glue.c
@@ -19,7 +19,7 @@
#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
-asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
+asmlinkage u16 crc_t10dif_pmull64(u16 init_crc, const u8 *buf, size_t len);
static int crct10dif_init(struct shash_desc *desc)
{
@@ -29,14 +29,14 @@ static int crct10dif_init(struct shash_desc *desc)
return 0;
}
-static int crct10dif_update(struct shash_desc *desc, const u8 *data,
- unsigned int length)
+static int crct10dif_update_ce(struct shash_desc *desc, const u8 *data,
+ unsigned int length)
{
u16 *crc = shash_desc_ctx(desc);
if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
kernel_neon_begin();
- *crc = crc_t10dif_pmull(*crc, data, length);
+ *crc = crc_t10dif_pmull64(*crc, data, length);
kernel_neon_end();
} else {
*crc = crc_t10dif_generic(*crc, data, length);
@@ -56,7 +56,7 @@ static int crct10dif_final(struct shash_desc *desc, u8 *out)
static struct shash_alg crc_t10dif_alg = {
.digestsize = CRC_T10DIF_DIGEST_SIZE,
.init = crct10dif_init,
- .update = crct10dif_update,
+ .update = crct10dif_update_ce,
.final = crct10dif_final,
.descsize = CRC_T10DIF_DIGEST_SIZE,
--
2.47.0.199.ga7371fff76-goog
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