[PATCH v4 17/20] crypto: arm64/aes-ghash - yield NEON after every block of input
From: Ard Biesheuvel
Date: Tue Dec 26 2017 - 05:32:28 EST
Avoid excessive scheduling delays under a preemptible kernel by
yielding the NEON after every block of input.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm64/crypto/ghash-ce-core.S | 113 ++++++++++++++------
arch/arm64/crypto/ghash-ce-glue.c | 28 +++--
2 files changed, 97 insertions(+), 44 deletions(-)
diff --git a/arch/arm64/crypto/ghash-ce-core.S b/arch/arm64/crypto/ghash-ce-core.S
index 11ebf1ae248a..dcffb9e77589 100644
--- a/arch/arm64/crypto/ghash-ce-core.S
+++ b/arch/arm64/crypto/ghash-ce-core.S
@@ -213,22 +213,31 @@
.endm
.macro __pmull_ghash, pn
- ld1 {SHASH.2d}, [x3]
- ld1 {XL.2d}, [x1]
+ frame_push 5
+
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+
+0: ld1 {SHASH.2d}, [x22]
+ ld1 {XL.2d}, [x20]
ext SHASH2.16b, SHASH.16b, SHASH.16b, #8
eor SHASH2.16b, SHASH2.16b, SHASH.16b
__pmull_pre_\pn
/* do the head block first, if supplied */
- cbz x4, 0f
- ld1 {T1.2d}, [x4]
- b 1f
+ cbz x23, 1f
+ ld1 {T1.2d}, [x23]
+ mov x23, xzr
+ b 2f
-0: ld1 {T1.2d}, [x2], #16
- sub w0, w0, #1
+1: ld1 {T1.2d}, [x21], #16
+ sub w19, w19, #1
-1: /* multiply XL by SHASH in GF(2^128) */
+2: /* multiply XL by SHASH in GF(2^128) */
CPU_LE( rev64 T1.16b, T1.16b )
ext T2.16b, XL.16b, XL.16b, #8
@@ -250,9 +259,18 @@ CPU_LE( rev64 T1.16b, T1.16b )
eor T2.16b, T2.16b, XH.16b
eor XL.16b, XL.16b, T2.16b
- cbnz w0, 0b
+ cbz w19, 3f
+
+ if_will_cond_yield_neon
+ st1 {XL.2d}, [x20]
+ do_cond_yield_neon
+ b 0b
+ endif_yield_neon
+
+ b 1b
- st1 {XL.2d}, [x1]
+3: st1 {XL.2d}, [x20]
+ frame_pop
ret
.endm
@@ -304,38 +322,55 @@ ENDPROC(pmull_ghash_update_p8)
.endm
.macro pmull_gcm_do_crypt, enc
- ld1 {SHASH.2d}, [x4]
- ld1 {XL.2d}, [x1]
- ldr x8, [x5, #8] // load lower counter
+ frame_push 10
+
+ mov x19, x0
+ mov x20, x1
+ mov x21, x2
+ mov x22, x3
+ mov x23, x4
+ mov x24, x5
+ mov x25, x6
+ mov x26, x7
+ .if \enc == 1
+ ldr x27, [sp, #96] // first stacked arg
+ .endif
+
+ ldr x28, [x24, #8] // load lower counter
+CPU_LE( rev x28, x28 )
+
+0: mov x0, x25
+ load_round_keys w26, x0
+ ld1 {SHASH.2d}, [x23]
+ ld1 {XL.2d}, [x20]
movi MASK.16b, #0xe1
ext SHASH2.16b, SHASH.16b, SHASH.16b, #8
-CPU_LE( rev x8, x8 )
shl MASK.2d, MASK.2d, #57
eor SHASH2.16b, SHASH2.16b, SHASH.16b
.if \enc == 1
- ld1 {KS.16b}, [x7]
+ ld1 {KS.16b}, [x27]
.endif
-0: ld1 {CTR.8b}, [x5] // load upper counter
- ld1 {INP.16b}, [x3], #16
- rev x9, x8
- add x8, x8, #1
- sub w0, w0, #1
+1: ld1 {CTR.8b}, [x24] // load upper counter
+ ld1 {INP.16b}, [x22], #16
+ rev x9, x28
+ add x28, x28, #1
+ sub w19, w19, #1
ins CTR.d[1], x9 // set lower counter
.if \enc == 1
eor INP.16b, INP.16b, KS.16b // encrypt input
- st1 {INP.16b}, [x2], #16
+ st1 {INP.16b}, [x21], #16
.endif
rev64 T1.16b, INP.16b
- cmp w6, #12
- b.ge 2f // AES-192/256?
+ cmp w26, #12
+ b.ge 4f // AES-192/256?
-1: enc_round CTR, v21
+2: enc_round CTR, v21
ext T2.16b, XL.16b, XL.16b, #8
ext IN1.16b, T1.16b, T1.16b, #8
@@ -390,27 +425,39 @@ CPU_LE( rev x8, x8 )
.if \enc == 0
eor INP.16b, INP.16b, KS.16b
- st1 {INP.16b}, [x2], #16
+ st1 {INP.16b}, [x21], #16
.endif
- cbnz w0, 0b
+ cbz w19, 3f
-CPU_LE( rev x8, x8 )
- st1 {XL.2d}, [x1]
- str x8, [x5, #8] // store lower counter
+ if_will_cond_yield_neon
+ st1 {XL.2d}, [x20]
+ .if \enc == 1
+ st1 {KS.16b}, [x27]
+ .endif
+ do_cond_yield_neon
+ b 0b
+ endif_yield_neon
+ b 1b
+
+3: st1 {XL.2d}, [x20]
.if \enc == 1
- st1 {KS.16b}, [x7]
+ st1 {KS.16b}, [x27]
.endif
+CPU_LE( rev x28, x28 )
+ str x28, [x24, #8] // store lower counter
+
+ frame_pop
ret
-2: b.eq 3f // AES-192?
+4: b.eq 5f // AES-192?
enc_round CTR, v17
enc_round CTR, v18
-3: enc_round CTR, v19
+5: enc_round CTR, v19
enc_round CTR, v20
- b 1b
+ b 2b
.endm
/*
diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
index cfc9c92814fd..7cf0b1aa6ea8 100644
--- a/arch/arm64/crypto/ghash-ce-glue.c
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -63,11 +63,12 @@ static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
asmlinkage void pmull_gcm_encrypt(int blocks, u64 dg[], u8 dst[],
const u8 src[], struct ghash_key const *k,
- u8 ctr[], int rounds, u8 ks[]);
+ u8 ctr[], u32 const rk[], int rounds,
+ u8 ks[]);
asmlinkage void pmull_gcm_decrypt(int blocks, u64 dg[], u8 dst[],
const u8 src[], struct ghash_key const *k,
- u8 ctr[], int rounds);
+ u8 ctr[], u32 const rk[], int rounds);
asmlinkage void pmull_gcm_encrypt_block(u8 dst[], u8 const src[],
u32 const rk[], int rounds);
@@ -368,26 +369,29 @@ static int gcm_encrypt(struct aead_request *req)
pmull_gcm_encrypt_block(ks, iv, NULL,
num_rounds(&ctx->aes_key));
put_unaligned_be32(3, iv + GCM_IV_SIZE);
+ kernel_neon_end();
- err = skcipher_walk_aead_encrypt(&walk, req, true);
+ err = skcipher_walk_aead_encrypt(&walk, req, false);
while (walk.nbytes >= AES_BLOCK_SIZE) {
int blocks = walk.nbytes / AES_BLOCK_SIZE;
+ kernel_neon_begin();
pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr,
walk.src.virt.addr, &ctx->ghash_key,
- iv, num_rounds(&ctx->aes_key), ks);
+ iv, ctx->aes_key.key_enc,
+ num_rounds(&ctx->aes_key), ks);
+ kernel_neon_end();
err = skcipher_walk_done(&walk,
walk.nbytes % AES_BLOCK_SIZE);
}
- kernel_neon_end();
} else {
__aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv,
num_rounds(&ctx->aes_key));
put_unaligned_be32(2, iv + GCM_IV_SIZE);
- err = skcipher_walk_aead_encrypt(&walk, req, true);
+ err = skcipher_walk_aead_encrypt(&walk, req, false);
while (walk.nbytes >= AES_BLOCK_SIZE) {
int blocks = walk.nbytes / AES_BLOCK_SIZE;
@@ -467,15 +471,19 @@ static int gcm_decrypt(struct aead_request *req)
pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc,
num_rounds(&ctx->aes_key));
put_unaligned_be32(2, iv + GCM_IV_SIZE);
+ kernel_neon_end();
- err = skcipher_walk_aead_decrypt(&walk, req, true);
+ err = skcipher_walk_aead_decrypt(&walk, req, false);
while (walk.nbytes >= AES_BLOCK_SIZE) {
int blocks = walk.nbytes / AES_BLOCK_SIZE;
+ kernel_neon_begin();
pmull_gcm_decrypt(blocks, dg, walk.dst.virt.addr,
walk.src.virt.addr, &ctx->ghash_key,
- iv, num_rounds(&ctx->aes_key));
+ iv, ctx->aes_key.key_enc,
+ num_rounds(&ctx->aes_key));
+ kernel_neon_end();
err = skcipher_walk_done(&walk,
walk.nbytes % AES_BLOCK_SIZE);
@@ -483,14 +491,12 @@ static int gcm_decrypt(struct aead_request *req)
if (walk.nbytes)
pmull_gcm_encrypt_block(iv, iv, NULL,
num_rounds(&ctx->aes_key));
-
- kernel_neon_end();
} else {
__aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv,
num_rounds(&ctx->aes_key));
put_unaligned_be32(2, iv + GCM_IV_SIZE);
- err = skcipher_walk_aead_decrypt(&walk, req, true);
+ err = skcipher_walk_aead_decrypt(&walk, req, false);
while (walk.nbytes >= AES_BLOCK_SIZE) {
int blocks = walk.nbytes / AES_BLOCK_SIZE;
--
2.11.0