* [PATCH 1/3] crypto: arm/aes-neonbs-ctr - deal with non-multiples of AES block size
2022-01-27 11:35 [PATCH 0/3] crypto: arm - simplify bit sliced AES Ard Biesheuvel
@ 2022-01-27 11:35 ` Ard Biesheuvel
2022-01-27 11:35 ` [PATCH 2/3] crypto: arm64/aes-neonbs-ctr - fallback to plain NEON for final chunk Ard Biesheuvel
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Ard Biesheuvel @ 2022-01-27 11:35 UTC (permalink / raw)
To: linux-crypto; +Cc: linux-arm-kernel, herbert, Ard Biesheuvel
Instead of falling back to C code to deal with the final bit of input
that is not a round multiple of the block size, handle this in the asm
code, permitting us to use overlapping loads and stores for performance,
and implement the 16-byte wide XOR using a single NEON instruction.
Since NEON loads and stores have a natural width of 16 bytes, we need to
handle inputs of less than 16 bytes in a special way, but this rarely
occurs in practice so it does not impact performance. All other input
sizes can be consumed directly by the NEON asm code, although it should
be noted that the core AES transform can still only process 128 bytes (8
AES blocks) at a time.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/arm/crypto/aes-neonbs-core.S | 105 ++++++++++++--------
arch/arm/crypto/aes-neonbs-glue.c | 35 +++----
2 files changed, 77 insertions(+), 63 deletions(-)
diff --git a/arch/arm/crypto/aes-neonbs-core.S b/arch/arm/crypto/aes-neonbs-core.S
index 7d0cc7f226a5..7b61032f29fa 100644
--- a/arch/arm/crypto/aes-neonbs-core.S
+++ b/arch/arm/crypto/aes-neonbs-core.S
@@ -758,29 +758,24 @@ ENTRY(aesbs_cbc_decrypt)
ENDPROC(aesbs_cbc_decrypt)
.macro next_ctr, q
- vmov.32 \q\()h[1], r10
+ vmov \q\()h, r9, r10
adds r10, r10, #1
- vmov.32 \q\()h[0], r9
adcs r9, r9, #0
- vmov.32 \q\()l[1], r8
+ vmov \q\()l, r7, r8
adcs r8, r8, #0
- vmov.32 \q\()l[0], r7
adc r7, r7, #0
vrev32.8 \q, \q
.endm
/*
* aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
- * int rounds, int blocks, u8 ctr[], u8 final[])
+ * int rounds, int bytes, u8 ctr[])
*/
ENTRY(aesbs_ctr_encrypt)
mov ip, sp
push {r4-r10, lr}
- ldm ip, {r5-r7} // load args 4-6
- teq r7, #0
- addne r5, r5, #1 // one extra block if final != 0
-
+ ldm ip, {r5, r6} // load args 4-5
vld1.8 {q0}, [r6] // load counter
vrev32.8 q1, q0
vmov r9, r10, d3
@@ -792,20 +787,19 @@ ENTRY(aesbs_ctr_encrypt)
adc r7, r7, #0
99: vmov q1, q0
+ sub lr, r5, #1
vmov q2, q0
+ adr ip, 0f
vmov q3, q0
+ and lr, lr, #112
vmov q4, q0
+ cmp r5, #112
vmov q5, q0
+ sub ip, ip, lr, lsl #1
vmov q6, q0
+ add ip, ip, lr, lsr #2
vmov q7, q0
-
- adr ip, 0f
- sub lr, r5, #1
- and lr, lr, #7
- cmp r5, #8
- sub ip, ip, lr, lsl #5
- sub ip, ip, lr, lsl #2
- movlt pc, ip // computed goto if blocks < 8
+ movle pc, ip // computed goto if bytes < 112
next_ctr q1
next_ctr q2
@@ -820,12 +814,14 @@ ENTRY(aesbs_ctr_encrypt)
bl aesbs_encrypt8
adr ip, 1f
- and lr, r5, #7
- cmp r5, #8
- movgt r4, #0
- ldrle r4, [sp, #40] // load final in the last round
- sub ip, ip, lr, lsl #2
- movlt pc, ip // computed goto if blocks < 8
+ sub lr, r5, #1
+ cmp r5, #128
+ bic lr, lr, #15
+ ands r4, r5, #15 // preserves C flag
+ teqcs r5, r5 // set Z flag if not last iteration
+ sub ip, ip, lr, lsr #2
+ rsb r4, r4, #16
+ movcc pc, ip // computed goto if bytes < 128
vld1.8 {q8}, [r1]!
vld1.8 {q9}, [r1]!
@@ -834,46 +830,70 @@ ENTRY(aesbs_ctr_encrypt)
vld1.8 {q12}, [r1]!
vld1.8 {q13}, [r1]!
vld1.8 {q14}, [r1]!
- teq r4, #0 // skip last block if 'final'
-1: bne 2f
+1: subne r1, r1, r4
vld1.8 {q15}, [r1]!
-2: adr ip, 3f
- cmp r5, #8
- sub ip, ip, lr, lsl #3
- movlt pc, ip // computed goto if blocks < 8
+ add ip, ip, #2f - 1b
veor q0, q0, q8
- vst1.8 {q0}, [r0]!
veor q1, q1, q9
- vst1.8 {q1}, [r0]!
veor q4, q4, q10
- vst1.8 {q4}, [r0]!
veor q6, q6, q11
- vst1.8 {q6}, [r0]!
veor q3, q3, q12
- vst1.8 {q3}, [r0]!
veor q7, q7, q13
- vst1.8 {q7}, [r0]!
veor q2, q2, q14
+ bne 3f
+ veor q5, q5, q15
+
+ movcc pc, ip // computed goto if bytes < 128
+
+ vst1.8 {q0}, [r0]!
+ vst1.8 {q1}, [r0]!
+ vst1.8 {q4}, [r0]!
+ vst1.8 {q6}, [r0]!
+ vst1.8 {q3}, [r0]!
+ vst1.8 {q7}, [r0]!
vst1.8 {q2}, [r0]!
- teq r4, #0 // skip last block if 'final'
- W(bne) 5f
-3: veor q5, q5, q15
+2: subne r0, r0, r4
vst1.8 {q5}, [r0]!
-4: next_ctr q0
+ next_ctr q0
- subs r5, r5, #8
+ subs r5, r5, #128
bgt 99b
vst1.8 {q0}, [r6]
pop {r4-r10, pc}
-5: vst1.8 {q5}, [r4]
- b 4b
+3: adr lr, .Lpermute_table + 16
+ cmp r5, #16 // Z flag remains cleared
+ sub lr, lr, r4
+ vld1.8 {q8-q9}, [lr]
+ vtbl.8 d16, {q5}, d16
+ vtbl.8 d17, {q5}, d17
+ veor q5, q8, q15
+ bcc 4f // have to reload prev if R5 < 16
+ vtbx.8 d10, {q2}, d18
+ vtbx.8 d11, {q2}, d19
+ mov pc, ip // branch back to VST sequence
+
+4: sub r0, r0, r4
+ vshr.s8 q9, q9, #7 // create mask for VBIF
+ vld1.8 {q8}, [r0] // reload
+ vbif q5, q8, q9
+ vst1.8 {q5}, [r0]
+ pop {r4-r10, pc}
ENDPROC(aesbs_ctr_encrypt)
+ .align 6
+.Lpermute_table:
+ .byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+ .byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+ .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07
+ .byte 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+ .byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+ .byte 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+
.macro next_tweak, out, in, const, tmp
vshr.s64 \tmp, \in, #63
vand \tmp, \tmp, \const
@@ -888,6 +908,7 @@ ENDPROC(aesbs_ctr_encrypt)
* aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[], int rounds,
* int blocks, u8 iv[], int reorder_last_tweak)
*/
+ .align 6
__xts_prepare8:
vld1.8 {q14}, [r7] // load iv
vmov.i32 d30, #0x87 // compose tweak mask vector
diff --git a/arch/arm/crypto/aes-neonbs-glue.c b/arch/arm/crypto/aes-neonbs-glue.c
index 5c6cd3c63cbc..f00f042ef357 100644
--- a/arch/arm/crypto/aes-neonbs-glue.c
+++ b/arch/arm/crypto/aes-neonbs-glue.c
@@ -37,7 +37,7 @@ asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[]);
asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
- int rounds, int blocks, u8 ctr[], u8 final[]);
+ int rounds, int blocks, u8 ctr[]);
asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[], int);
@@ -243,32 +243,25 @@ static int ctr_encrypt(struct skcipher_request *req)
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes > 0) {
- unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
- u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
+ const u8 *src = walk.src.virt.addr;
+ u8 *dst = walk.dst.virt.addr;
+ int bytes = walk.nbytes;
- if (walk.nbytes < walk.total) {
- blocks = round_down(blocks,
- walk.stride / AES_BLOCK_SIZE);
- final = NULL;
- }
+ if (unlikely(bytes < AES_BLOCK_SIZE))
+ src = dst = memcpy(buf + sizeof(buf) - bytes,
+ src, bytes);
+ else if (walk.nbytes < walk.total)
+ bytes &= ~(8 * AES_BLOCK_SIZE - 1);
kernel_neon_begin();
- aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
- ctx->rk, ctx->rounds, blocks, walk.iv, final);
+ aesbs_ctr_encrypt(dst, src, ctx->rk, ctx->rounds, bytes, walk.iv);
kernel_neon_end();
- if (final) {
- u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
- u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
+ if (unlikely(bytes < AES_BLOCK_SIZE))
+ memcpy(walk.dst.virt.addr,
+ buf + sizeof(buf) - bytes, bytes);
- crypto_xor_cpy(dst, src, final,
- walk.total % AES_BLOCK_SIZE);
-
- err = skcipher_walk_done(&walk, 0);
- break;
- }
- err = skcipher_walk_done(&walk,
- walk.nbytes - blocks * AES_BLOCK_SIZE);
+ err = skcipher_walk_done(&walk, walk.nbytes - bytes);
}
return err;
--
2.30.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/3] crypto: arm64/aes-neonbs-ctr - fallback to plain NEON for final chunk
2022-01-27 11:35 [PATCH 0/3] crypto: arm - simplify bit sliced AES Ard Biesheuvel
2022-01-27 11:35 ` [PATCH 1/3] crypto: arm/aes-neonbs-ctr - deal with non-multiples of AES block size Ard Biesheuvel
@ 2022-01-27 11:35 ` Ard Biesheuvel
2022-01-27 11:35 ` [PATCH 3/3] crypto: arm64/aes-neonbs-xts - use plain NEON for non-power-of-2 input sizes Ard Biesheuvel
2022-02-05 4:32 ` [PATCH 0/3] crypto: arm - simplify bit sliced AES Herbert Xu
3 siblings, 0 replies; 5+ messages in thread
From: Ard Biesheuvel @ 2022-01-27 11:35 UTC (permalink / raw)
To: linux-crypto; +Cc: linux-arm-kernel, herbert, Ard Biesheuvel
Instead of processing the entire input with the 8-way bit sliced
algorithm, which is sub-optimal for inputs that are not a multiple of
128 bytes in size, invoke the plain NEON version of CTR for the
remainder of the input after processing the bulk using 128 byte strides.
This allows us to greatly simplify the asm code that implements CTR, and
get rid of all the branches and special code paths. It also gains us a
couple of percent of performance.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/arm64/crypto/aes-glue.c | 1 +
arch/arm64/crypto/aes-neonbs-core.S | 132 ++++----------------
arch/arm64/crypto/aes-neonbs-glue.c | 64 +++++-----
3 files changed, 55 insertions(+), 142 deletions(-)
diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c
index 30b7cc6a7079..3127794c09d6 100644
--- a/arch/arm64/crypto/aes-glue.c
+++ b/arch/arm64/crypto/aes-glue.c
@@ -983,6 +983,7 @@ module_cpu_feature_match(AES, aes_init);
module_init(aes_init);
EXPORT_SYMBOL(neon_aes_ecb_encrypt);
EXPORT_SYMBOL(neon_aes_cbc_encrypt);
+EXPORT_SYMBOL(neon_aes_ctr_encrypt);
EXPORT_SYMBOL(neon_aes_xts_encrypt);
EXPORT_SYMBOL(neon_aes_xts_decrypt);
#endif
diff --git a/arch/arm64/crypto/aes-neonbs-core.S b/arch/arm64/crypto/aes-neonbs-core.S
index a3405b8c344b..f2761481181d 100644
--- a/arch/arm64/crypto/aes-neonbs-core.S
+++ b/arch/arm64/crypto/aes-neonbs-core.S
@@ -869,133 +869,51 @@ SYM_FUNC_END(aesbs_xts_decrypt)
/*
* aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
- * int rounds, int blocks, u8 iv[], u8 final[])
+ * int rounds, int blocks, u8 iv[])
*/
SYM_FUNC_START(aesbs_ctr_encrypt)
- frame_push 8
+ stp x29, x30, [sp, #-16]!
+ mov x29, sp
- mov x19, x0
- mov x20, x1
- mov x21, x2
- mov x22, x3
- mov x23, x4
- mov x24, x5
- mov x25, x6
-
- cmp x25, #0
- cset x26, ne
- add x23, x23, x26 // do one extra block if final
-
- ldp x7, x8, [x24]
- ld1 {v0.16b}, [x24]
+ ldp x7, x8, [x5]
+ ld1 {v0.16b}, [x5]
CPU_LE( rev x7, x7 )
CPU_LE( rev x8, x8 )
adds x8, x8, #1
adc x7, x7, xzr
-99: mov x9, #1
- lsl x9, x9, x23
- subs w23, w23, #8
- csel x23, x23, xzr, pl
- csel x9, x9, xzr, le
-
- tbnz x9, #1, 0f
- next_ctr v1
- tbnz x9, #2, 0f
+0: next_ctr v1
next_ctr v2
- tbnz x9, #3, 0f
next_ctr v3
- tbnz x9, #4, 0f
next_ctr v4
- tbnz x9, #5, 0f
next_ctr v5
- tbnz x9, #6, 0f
next_ctr v6
- tbnz x9, #7, 0f
next_ctr v7
-0: mov bskey, x21
- mov rounds, x22
+ mov bskey, x2
+ mov rounds, x3
bl aesbs_encrypt8
- lsr x9, x9, x26 // disregard the extra block
- tbnz x9, #0, 0f
-
- ld1 {v8.16b}, [x20], #16
- eor v0.16b, v0.16b, v8.16b
- st1 {v0.16b}, [x19], #16
- tbnz x9, #1, 1f
-
- ld1 {v9.16b}, [x20], #16
- eor v1.16b, v1.16b, v9.16b
- st1 {v1.16b}, [x19], #16
- tbnz x9, #2, 2f
-
- ld1 {v10.16b}, [x20], #16
- eor v4.16b, v4.16b, v10.16b
- st1 {v4.16b}, [x19], #16
- tbnz x9, #3, 3f
+ ld1 { v8.16b-v11.16b}, [x1], #64
+ ld1 {v12.16b-v15.16b}, [x1], #64
- ld1 {v11.16b}, [x20], #16
- eor v6.16b, v6.16b, v11.16b
- st1 {v6.16b}, [x19], #16
- tbnz x9, #4, 4f
+ eor v8.16b, v0.16b, v8.16b
+ eor v9.16b, v1.16b, v9.16b
+ eor v10.16b, v4.16b, v10.16b
+ eor v11.16b, v6.16b, v11.16b
+ eor v12.16b, v3.16b, v12.16b
+ eor v13.16b, v7.16b, v13.16b
+ eor v14.16b, v2.16b, v14.16b
+ eor v15.16b, v5.16b, v15.16b
- ld1 {v12.16b}, [x20], #16
- eor v3.16b, v3.16b, v12.16b
- st1 {v3.16b}, [x19], #16
- tbnz x9, #5, 5f
+ st1 { v8.16b-v11.16b}, [x0], #64
+ st1 {v12.16b-v15.16b}, [x0], #64
- ld1 {v13.16b}, [x20], #16
- eor v7.16b, v7.16b, v13.16b
- st1 {v7.16b}, [x19], #16
- tbnz x9, #6, 6f
-
- ld1 {v14.16b}, [x20], #16
- eor v2.16b, v2.16b, v14.16b
- st1 {v2.16b}, [x19], #16
- tbnz x9, #7, 7f
+ next_ctr v0
+ subs x4, x4, #8
+ b.gt 0b
- ld1 {v15.16b}, [x20], #16
- eor v5.16b, v5.16b, v15.16b
- st1 {v5.16b}, [x19], #16
-
-8: next_ctr v0
- st1 {v0.16b}, [x24]
- cbz x23, .Lctr_done
-
- b 99b
-
-.Lctr_done:
- frame_pop
+ st1 {v0.16b}, [x5]
+ ldp x29, x30, [sp], #16
ret
-
- /*
- * If we are handling the tail of the input (x6 != NULL), return the
- * final keystream block back to the caller.
- */
-0: cbz x25, 8b
- st1 {v0.16b}, [x25]
- b 8b
-1: cbz x25, 8b
- st1 {v1.16b}, [x25]
- b 8b
-2: cbz x25, 8b
- st1 {v4.16b}, [x25]
- b 8b
-3: cbz x25, 8b
- st1 {v6.16b}, [x25]
- b 8b
-4: cbz x25, 8b
- st1 {v3.16b}, [x25]
- b 8b
-5: cbz x25, 8b
- st1 {v7.16b}, [x25]
- b 8b
-6: cbz x25, 8b
- st1 {v2.16b}, [x25]
- b 8b
-7: cbz x25, 8b
- st1 {v5.16b}, [x25]
- b 8b
SYM_FUNC_END(aesbs_ctr_encrypt)
diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
index 8df6ad8cb09d..3189003e1cbe 100644
--- a/arch/arm64/crypto/aes-neonbs-glue.c
+++ b/arch/arm64/crypto/aes-neonbs-glue.c
@@ -34,7 +34,7 @@ asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[]);
asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
- int rounds, int blocks, u8 iv[], u8 final[]);
+ int rounds, int blocks, u8 iv[]);
asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[]);
@@ -46,6 +46,8 @@ asmlinkage void neon_aes_ecb_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks);
asmlinkage void neon_aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks, u8 iv[]);
+asmlinkage void neon_aes_ctr_encrypt(u8 out[], u8 const in[], u32 const rk[],
+ int rounds, int bytes, u8 ctr[]);
asmlinkage void neon_aes_xts_encrypt(u8 out[], u8 const in[],
u32 const rk1[], int rounds, int bytes,
u32 const rk2[], u8 iv[], int first);
@@ -58,7 +60,7 @@ struct aesbs_ctx {
int rounds;
} __aligned(AES_BLOCK_SIZE);
-struct aesbs_cbc_ctx {
+struct aesbs_cbc_ctr_ctx {
struct aesbs_ctx key;
u32 enc[AES_MAX_KEYLENGTH_U32];
};
@@ -128,10 +130,10 @@ static int ecb_decrypt(struct skcipher_request *req)
return __ecb_crypt(req, aesbs_ecb_decrypt);
}
-static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
+static int aesbs_cbc_ctr_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
- struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct aesbs_cbc_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_aes_ctx rk;
int err;
@@ -154,7 +156,7 @@ static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
static int cbc_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct aesbs_cbc_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;
@@ -177,7 +179,7 @@ static int cbc_encrypt(struct skcipher_request *req)
static int cbc_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct aesbs_cbc_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;
@@ -205,40 +207,32 @@ static int cbc_decrypt(struct skcipher_request *req)
static int ctr_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
- struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct aesbs_cbc_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
- u8 buf[AES_BLOCK_SIZE];
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes > 0) {
- unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
- u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
-
- if (walk.nbytes < walk.total) {
- blocks = round_down(blocks,
- walk.stride / AES_BLOCK_SIZE);
- final = NULL;
- }
+ int blocks = (walk.nbytes / AES_BLOCK_SIZE) & ~7;
+ int nbytes = walk.nbytes % (8 * AES_BLOCK_SIZE);
+ const u8 *src = walk.src.virt.addr;
+ u8 *dst = walk.dst.virt.addr;
kernel_neon_begin();
- aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
- ctx->rk, ctx->rounds, blocks, walk.iv, final);
- kernel_neon_end();
-
- if (final) {
- u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
- u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
-
- crypto_xor_cpy(dst, src, final,
- walk.total % AES_BLOCK_SIZE);
-
- err = skcipher_walk_done(&walk, 0);
- break;
+ if (blocks >= 8) {
+ aesbs_ctr_encrypt(dst, src, ctx->key.rk, ctx->key.rounds,
+ blocks, walk.iv);
+ dst += blocks * AES_BLOCK_SIZE;
+ src += blocks * AES_BLOCK_SIZE;
}
- err = skcipher_walk_done(&walk,
- walk.nbytes - blocks * AES_BLOCK_SIZE);
+ if (nbytes && walk.nbytes == walk.total) {
+ neon_aes_ctr_encrypt(dst, src, ctx->enc, ctx->key.rounds,
+ nbytes, walk.iv);
+ nbytes = 0;
+ }
+ kernel_neon_end();
+ err = skcipher_walk_done(&walk, nbytes);
}
return err;
}
@@ -402,14 +396,14 @@ static struct skcipher_alg aes_algs[] = { {
.base.cra_driver_name = "cbc-aes-neonbs",
.base.cra_priority = 250,
.base.cra_blocksize = AES_BLOCK_SIZE,
- .base.cra_ctxsize = sizeof(struct aesbs_cbc_ctx),
+ .base.cra_ctxsize = sizeof(struct aesbs_cbc_ctr_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.walksize = 8 * AES_BLOCK_SIZE,
.ivsize = AES_BLOCK_SIZE,
- .setkey = aesbs_cbc_setkey,
+ .setkey = aesbs_cbc_ctr_setkey,
.encrypt = cbc_encrypt,
.decrypt = cbc_decrypt,
}, {
@@ -417,7 +411,7 @@ static struct skcipher_alg aes_algs[] = { {
.base.cra_driver_name = "ctr-aes-neonbs",
.base.cra_priority = 250,
.base.cra_blocksize = 1,
- .base.cra_ctxsize = sizeof(struct aesbs_ctx),
+ .base.cra_ctxsize = sizeof(struct aesbs_cbc_ctr_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = AES_MIN_KEY_SIZE,
@@ -425,7 +419,7 @@ static struct skcipher_alg aes_algs[] = { {
.chunksize = AES_BLOCK_SIZE,
.walksize = 8 * AES_BLOCK_SIZE,
.ivsize = AES_BLOCK_SIZE,
- .setkey = aesbs_setkey,
+ .setkey = aesbs_cbc_ctr_setkey,
.encrypt = ctr_encrypt,
.decrypt = ctr_encrypt,
}, {
--
2.30.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/3] crypto: arm64/aes-neonbs-xts - use plain NEON for non-power-of-2 input sizes
2022-01-27 11:35 [PATCH 0/3] crypto: arm - simplify bit sliced AES Ard Biesheuvel
2022-01-27 11:35 ` [PATCH 1/3] crypto: arm/aes-neonbs-ctr - deal with non-multiples of AES block size Ard Biesheuvel
2022-01-27 11:35 ` [PATCH 2/3] crypto: arm64/aes-neonbs-ctr - fallback to plain NEON for final chunk Ard Biesheuvel
@ 2022-01-27 11:35 ` Ard Biesheuvel
2022-02-05 4:32 ` [PATCH 0/3] crypto: arm - simplify bit sliced AES Herbert Xu
3 siblings, 0 replies; 5+ messages in thread
From: Ard Biesheuvel @ 2022-01-27 11:35 UTC (permalink / raw)
To: linux-crypto; +Cc: linux-arm-kernel, herbert, Ard Biesheuvel
Even though the kernel's implementations of AES-XTS were updated to
implement ciphertext stealing and can operate on inputs of any size
larger than or equal to the AES block size, this feature is rarely used
in practice.
In fact, in the kernel, AES-XTS is only used to operate on 4096 or 512
byte blocks, which means that not only the ciphertext stealing is
effectively dead code, the logic in the bit sliced NEON implementation
to deal with fewer than 8 blocks at a time is also never used.
Since the bit-sliced NEON driver already depends on the plain NEON
version, which is slower but can operate on smaller data quantities more
straightforwardly, let's fallback to the plain NEON implementation of
XTS for any residual inputs that are not multiples of 128 bytes. This
allows us to remove a lot of complicated logic that rarely gets
exercised in practice.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
arch/arm64/crypto/aes-neonbs-core.S | 132 ++++++--------------
arch/arm64/crypto/aes-neonbs-glue.c | 33 ++---
2 files changed, 57 insertions(+), 108 deletions(-)
diff --git a/arch/arm64/crypto/aes-neonbs-core.S b/arch/arm64/crypto/aes-neonbs-core.S
index f2761481181d..d427f4556b6e 100644
--- a/arch/arm64/crypto/aes-neonbs-core.S
+++ b/arch/arm64/crypto/aes-neonbs-core.S
@@ -735,119 +735,67 @@ SYM_FUNC_END(aesbs_cbc_decrypt)
* int blocks, u8 iv[])
*/
SYM_FUNC_START_LOCAL(__xts_crypt8)
- mov x6, #1
- lsl x6, x6, x23
- subs w23, w23, #8
- csel x23, x23, xzr, pl
- csel x6, x6, xzr, mi
+ movi v18.2s, #0x1
+ movi v19.2s, #0x87
+ uzp1 v18.4s, v18.4s, v19.4s
+
+ ld1 {v0.16b-v3.16b}, [x1], #64
+ ld1 {v4.16b-v7.16b}, [x1], #64
+
+ next_tweak v26, v25, v18, v19
+ next_tweak v27, v26, v18, v19
+ next_tweak v28, v27, v18, v19
+ next_tweak v29, v28, v18, v19
+ next_tweak v30, v29, v18, v19
+ next_tweak v31, v30, v18, v19
+ next_tweak v16, v31, v18, v19
+ next_tweak v17, v16, v18, v19
- ld1 {v0.16b}, [x20], #16
- next_tweak v26, v25, v30, v31
eor v0.16b, v0.16b, v25.16b
- tbnz x6, #1, 0f
-
- ld1 {v1.16b}, [x20], #16
- next_tweak v27, v26, v30, v31
eor v1.16b, v1.16b, v26.16b
- tbnz x6, #2, 0f
-
- ld1 {v2.16b}, [x20], #16
- next_tweak v28, v27, v30, v31
eor v2.16b, v2.16b, v27.16b
- tbnz x6, #3, 0f
-
- ld1 {v3.16b}, [x20], #16
- next_tweak v29, v28, v30, v31
eor v3.16b, v3.16b, v28.16b
- tbnz x6, #4, 0f
-
- ld1 {v4.16b}, [x20], #16
- str q29, [sp, #.Lframe_local_offset]
eor v4.16b, v4.16b, v29.16b
- next_tweak v29, v29, v30, v31
- tbnz x6, #5, 0f
-
- ld1 {v5.16b}, [x20], #16
- str q29, [sp, #.Lframe_local_offset + 16]
- eor v5.16b, v5.16b, v29.16b
- next_tweak v29, v29, v30, v31
- tbnz x6, #6, 0f
+ eor v5.16b, v5.16b, v30.16b
+ eor v6.16b, v6.16b, v31.16b
+ eor v7.16b, v7.16b, v16.16b
- ld1 {v6.16b}, [x20], #16
- str q29, [sp, #.Lframe_local_offset + 32]
- eor v6.16b, v6.16b, v29.16b
- next_tweak v29, v29, v30, v31
- tbnz x6, #7, 0f
+ stp q16, q17, [sp, #16]
- ld1 {v7.16b}, [x20], #16
- str q29, [sp, #.Lframe_local_offset + 48]
- eor v7.16b, v7.16b, v29.16b
- next_tweak v29, v29, v30, v31
-
-0: mov bskey, x21
- mov rounds, x22
+ mov bskey, x2
+ mov rounds, x3
br x16
SYM_FUNC_END(__xts_crypt8)
.macro __xts_crypt, do8, o0, o1, o2, o3, o4, o5, o6, o7
- frame_push 6, 64
-
- mov x19, x0
- mov x20, x1
- mov x21, x2
- mov x22, x3
- mov x23, x4
- mov x24, x5
+ stp x29, x30, [sp, #-48]!
+ mov x29, sp
- movi v30.2s, #0x1
- movi v25.2s, #0x87
- uzp1 v30.4s, v30.4s, v25.4s
- ld1 {v25.16b}, [x24]
+ ld1 {v25.16b}, [x5]
-99: adr x16, \do8
+0: adr x16, \do8
bl __xts_crypt8
- ldp q16, q17, [sp, #.Lframe_local_offset]
- ldp q18, q19, [sp, #.Lframe_local_offset + 32]
+ eor v16.16b, \o0\().16b, v25.16b
+ eor v17.16b, \o1\().16b, v26.16b
+ eor v18.16b, \o2\().16b, v27.16b
+ eor v19.16b, \o3\().16b, v28.16b
- eor \o0\().16b, \o0\().16b, v25.16b
- eor \o1\().16b, \o1\().16b, v26.16b
- eor \o2\().16b, \o2\().16b, v27.16b
- eor \o3\().16b, \o3\().16b, v28.16b
+ ldp q24, q25, [sp, #16]
- st1 {\o0\().16b}, [x19], #16
- mov v25.16b, v26.16b
- tbnz x6, #1, 1f
- st1 {\o1\().16b}, [x19], #16
- mov v25.16b, v27.16b
- tbnz x6, #2, 1f
- st1 {\o2\().16b}, [x19], #16
- mov v25.16b, v28.16b
- tbnz x6, #3, 1f
- st1 {\o3\().16b}, [x19], #16
- mov v25.16b, v29.16b
- tbnz x6, #4, 1f
-
- eor \o4\().16b, \o4\().16b, v16.16b
- eor \o5\().16b, \o5\().16b, v17.16b
- eor \o6\().16b, \o6\().16b, v18.16b
- eor \o7\().16b, \o7\().16b, v19.16b
-
- st1 {\o4\().16b}, [x19], #16
- tbnz x6, #5, 1f
- st1 {\o5\().16b}, [x19], #16
- tbnz x6, #6, 1f
- st1 {\o6\().16b}, [x19], #16
- tbnz x6, #7, 1f
- st1 {\o7\().16b}, [x19], #16
+ eor v20.16b, \o4\().16b, v29.16b
+ eor v21.16b, \o5\().16b, v30.16b
+ eor v22.16b, \o6\().16b, v31.16b
+ eor v23.16b, \o7\().16b, v24.16b
- cbz x23, 1f
- st1 {v25.16b}, [x24]
+ st1 {v16.16b-v19.16b}, [x0], #64
+ st1 {v20.16b-v23.16b}, [x0], #64
- b 99b
+ subs x4, x4, #8
+ b.gt 0b
-1: st1 {v25.16b}, [x24]
- frame_pop
+ st1 {v25.16b}, [x5]
+ ldp x29, x30, [sp], #48
ret
.endm
diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
index 3189003e1cbe..bac4cabef607 100644
--- a/arch/arm64/crypto/aes-neonbs-glue.c
+++ b/arch/arm64/crypto/aes-neonbs-glue.c
@@ -302,23 +302,18 @@ static int __xts_crypt(struct skcipher_request *req, bool encrypt,
return err;
while (walk.nbytes >= AES_BLOCK_SIZE) {
- unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
-
- if (walk.nbytes < walk.total || walk.nbytes % AES_BLOCK_SIZE)
- blocks = round_down(blocks,
- walk.stride / AES_BLOCK_SIZE);
-
+ int blocks = (walk.nbytes / AES_BLOCK_SIZE) & ~7;
out = walk.dst.virt.addr;
in = walk.src.virt.addr;
nbytes = walk.nbytes;
kernel_neon_begin();
- if (likely(blocks > 6)) { /* plain NEON is faster otherwise */
- if (first)
+ if (blocks >= 8) {
+ if (first == 1)
neon_aes_ecb_encrypt(walk.iv, walk.iv,
ctx->twkey,
ctx->key.rounds, 1);
- first = 0;
+ first = 2;
fn(out, in, ctx->key.rk, ctx->key.rounds, blocks,
walk.iv);
@@ -327,10 +322,17 @@ static int __xts_crypt(struct skcipher_request *req, bool encrypt,
in += blocks * AES_BLOCK_SIZE;
nbytes -= blocks * AES_BLOCK_SIZE;
}
-
- if (walk.nbytes == walk.total && nbytes > 0)
- goto xts_tail;
-
+ if (walk.nbytes == walk.total && nbytes > 0) {
+ if (encrypt)
+ neon_aes_xts_encrypt(out, in, ctx->cts.key_enc,
+ ctx->key.rounds, nbytes,
+ ctx->twkey, walk.iv, first);
+ else
+ neon_aes_xts_decrypt(out, in, ctx->cts.key_dec,
+ ctx->key.rounds, nbytes,
+ ctx->twkey, walk.iv, first);
+ nbytes = first = 0;
+ }
kernel_neon_end();
err = skcipher_walk_done(&walk, nbytes);
}
@@ -355,13 +357,12 @@ static int __xts_crypt(struct skcipher_request *req, bool encrypt,
nbytes = walk.nbytes;
kernel_neon_begin();
-xts_tail:
if (encrypt)
neon_aes_xts_encrypt(out, in, ctx->cts.key_enc, ctx->key.rounds,
- nbytes, ctx->twkey, walk.iv, first ?: 2);
+ nbytes, ctx->twkey, walk.iv, first);
else
neon_aes_xts_decrypt(out, in, ctx->cts.key_dec, ctx->key.rounds,
- nbytes, ctx->twkey, walk.iv, first ?: 2);
+ nbytes, ctx->twkey, walk.iv, first);
kernel_neon_end();
return skcipher_walk_done(&walk, 0);
--
2.30.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 0/3] crypto: arm - simplify bit sliced AES
2022-01-27 11:35 [PATCH 0/3] crypto: arm - simplify bit sliced AES Ard Biesheuvel
` (2 preceding siblings ...)
2022-01-27 11:35 ` [PATCH 3/3] crypto: arm64/aes-neonbs-xts - use plain NEON for non-power-of-2 input sizes Ard Biesheuvel
@ 2022-02-05 4:32 ` Herbert Xu
3 siblings, 0 replies; 5+ messages in thread
From: Herbert Xu @ 2022-02-05 4:32 UTC (permalink / raw)
To: Ard Biesheuvel; +Cc: linux-crypto, linux-arm-kernel
On Thu, Jan 27, 2022 at 12:35:42PM +0100, Ard Biesheuvel wrote:
> This contains a couple of improvements/simplifications for the bit
> sliced AES driver implemented on ARM and arm64.
>
> Ard Biesheuvel (3):
> crypto: arm/aes-neonbs-ctr - deal with non-multiples of AES block size
> crypto: arm64/aes-neonbs-ctr - fallback to plain NEON for final chunk
> crypto: arm64/aes-neonbs-xts - use plain NEON for non-power-of-2 input
> sizes
>
> arch/arm/crypto/aes-neonbs-core.S | 105 ++++----
> arch/arm/crypto/aes-neonbs-glue.c | 35 ++-
> arch/arm64/crypto/aes-glue.c | 1 +
> arch/arm64/crypto/aes-neonbs-core.S | 264 +++++---------------
> arch/arm64/crypto/aes-neonbs-glue.c | 97 ++++---
> 5 files changed, 189 insertions(+), 313 deletions(-)
All applied. Thanks.
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply [flat|nested] 5+ messages in thread