crypto: arm/crct10dif - Macroify PMULL asm code

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@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ard Biesheuvel 2024-11-05 17:09:05 +01:00 committed by Herbert Xu
parent fcf27785ae
commit 802d8d110c
2 changed files with 83 additions and 81 deletions

View File

@ -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

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@ -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,
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,