There are two ways to implement SIMD accelerated GCM on arm64:
- using the PMULL instructions for carryless 64x64->128 multiplication,
in which case the architecture guarantees that the AES instructions are
available as well, and so we can use the AEAD implementation that combines
both,
- using the PMULL instructions for carryless 8x8->16 bit multiplication,
which is implemented as a shash, and can be combined with any ctr(aes)
implementation by the generic GCM AEAD template driver.
So let's drop the 64x64->128 shash driver, which is never needed for GCM,
and not suitable for use anywhere else.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/arm64/crypto/ghash-ce-glue.c | 90 +++-----------------
1 file changed, 12 insertions(+), 78 deletions(-)
diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
index 22831d3b7f62..be63d8b5152c 100644
--- a/arch/arm64/crypto/ghash-ce-glue.c
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -113,12 +113,8 @@ static void ghash_do_update(int blocks, u64 dg[], const char *src,
/* avoid hogging the CPU for too long */
#define MAX_BLOCKS (SZ_64K / GHASH_BLOCK_SIZE)
-static int __ghash_update(struct shash_desc *desc, const u8 *src,
- unsigned int len,
- void (*simd_update)(int blocks, u64 dg[],
- const char *src,
- struct ghash_key const *k,
- const char *head))
+static int ghash_update(struct shash_desc *desc, const u8 *src,
+ unsigned int len)
{
struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
@@ -145,7 +141,7 @@ static int __ghash_update(struct shash_desc *desc, const u8 *src,
ghash_do_update(chunk, ctx->digest, src, key,
partial ? ctx->buf : NULL,
- simd_update);
+ pmull_ghash_update_p8);
blocks -= chunk;
src += chunk * GHASH_BLOCK_SIZE;
@@ -157,19 +153,7 @@ static int __ghash_update(struct shash_desc *desc, const u8 *src,
return 0;
}
-static int ghash_update_p8(struct shash_desc *desc, const u8 *src,
- unsigned int len)
-{
- return __ghash_update(desc, src, len, pmull_ghash_update_p8);
-}
-
-static int ghash_update_p64(struct shash_desc *desc, const u8 *src,
- unsigned int len)
-{
- return __ghash_update(desc, src, len, pmull_ghash_update_p64);
-}
-
-static int ghash_final_p8(struct shash_desc *desc, u8 *dst)
+static int ghash_final(struct shash_desc *desc, u8 *dst)
{
struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
@@ -189,26 +173,6 @@ static int ghash_final_p8(struct shash_desc *desc, u8 *dst)
return 0;
}
-static int ghash_final_p64(struct shash_desc *desc, u8 *dst)
-{
- struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
- unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
-
- if (partial) {
- struct ghash_key *key = crypto_shash_ctx(desc->tfm);
-
- memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
-
- ghash_do_update(1, ctx->digest, ctx->buf, key, NULL,
- pmull_ghash_update_p64);
- }
- put_unaligned_be64(ctx->digest[1], dst);
- put_unaligned_be64(ctx->digest[0], dst + 8);
-
- *ctx = (struct ghash_desc_ctx){};
- return 0;
-}
-
static void ghash_reflect(u64 h[], const be128 *k)
{
u64 carry = be64_to_cpu(k->a) & BIT(63) ? 1 : 0;
@@ -254,7 +218,7 @@ static int ghash_setkey(struct crypto_shash *tfm,
return __ghash_setkey(key, inkey, keylen);
}
-static struct shash_alg ghash_alg[] = {{
+static struct shash_alg ghash_alg = {
.base.cra_name = "ghash",
.base.cra_driver_name = "ghash-neon",
.base.cra_priority = 150,
@@ -264,25 +228,11 @@ static struct shash_alg ghash_alg[] = {{
.digestsize = GHASH_DIGEST_SIZE,
.init = ghash_init,
- .update = ghash_update_p8,
- .final = ghash_final_p8,
- .setkey = ghash_setkey,
- .descsize = sizeof(struct ghash_desc_ctx),
-}, {
- .base.cra_name = "ghash",
- .base.cra_driver_name = "ghash-ce",
- .base.cra_priority = 200,
- .base.cra_blocksize = GHASH_BLOCK_SIZE,
- .base.cra_ctxsize = sizeof(struct ghash_key),
- .base.cra_module = THIS_MODULE,
-
- .digestsize = GHASH_DIGEST_SIZE,
- .init = ghash_init,
- .update = ghash_update_p64,
- .final = ghash_final_p64,
+ .update = ghash_update,
+ .final = ghash_final,
.setkey = ghash_setkey,
.descsize = sizeof(struct ghash_desc_ctx),
-}};
+};
static int num_rounds(struct crypto_aes_ctx *ctx)
{
@@ -641,37 +591,21 @@ static struct aead_alg gcm_aes_alg = {
static int __init ghash_ce_mod_init(void)
{
- int ret;
-
if (!cpu_have_named_feature(ASIMD))
return -ENODEV;
if (cpu_have_named_feature(PMULL))
- ret = crypto_register_shashes(ghash_alg,
- ARRAY_SIZE(ghash_alg));
- else
- /* only register the first array element */
- ret = crypto_register_shash(ghash_alg);
+ return crypto_register_aead(&gcm_aes_alg);
- if (ret)
- return ret;
-
- if (cpu_have_named_feature(PMULL)) {
- ret = crypto_register_aead(&gcm_aes_alg);
- if (ret)
- crypto_unregister_shashes(ghash_alg,
- ARRAY_SIZE(ghash_alg));
- }
- return ret;
+ return crypto_register_shash(&ghash_alg);
}
static void __exit ghash_ce_mod_exit(void)
{
if (cpu_have_named_feature(PMULL))
- crypto_unregister_shashes(ghash_alg, ARRAY_SIZE(ghash_alg));
+ crypto_unregister_aead(&gcm_aes_alg);
else
- crypto_unregister_shash(ghash_alg);
- crypto_unregister_aead(&gcm_aes_alg);
+ crypto_unregister_shash(&ghash_alg);
}
static const struct cpu_feature ghash_cpu_feature[] = {
--
2.20.1
