From 543ea178fbfadeaf79e15766ac989f3351349f02 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 12 Apr 2024 20:17:28 -0700 Subject: crypto: x86/aes-xts - optimize size of instructions operating on lengths x86_64 has the "interesting" property that the instruction size is generally a bit shorter for instructions that operate on the 32-bit (or less) part of registers, or registers that are in the original set of 8. This patch adjusts the AES-XTS code to take advantage of that property by changing the LEN parameter from size_t to unsigned int (which is all that's needed and is what the non-AVX implementation uses) and using the %eax register for KEYLEN. This decreases the size of aes-xts-avx-x86_64.o by 1.2%. Note that changing the kmovq to kmovd was going to be needed anyway to make the AVX10/256 code really work on CPUs that don't support 512-bit vectors (since the AVX10 spec says that 64-bit opmask instructions will only be supported on processors that support 512-bit vectors). Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- arch/x86/crypto/aes-xts-avx-x86_64.S | 40 +++++++++++++++++++----------------- arch/x86/crypto/aesni-intel_glue.c | 18 ++++++++-------- 2 files changed, 30 insertions(+), 28 deletions(-) diff --git a/arch/x86/crypto/aes-xts-avx-x86_64.S b/arch/x86/crypto/aes-xts-avx-x86_64.S index 802d3b90d337f..48f97b79f7a9c 100644 --- a/arch/x86/crypto/aes-xts-avx-x86_64.S +++ b/arch/x86/crypto/aes-xts-avx-x86_64.S @@ -85,14 +85,16 @@ // advanced to point to 7th-from-last round key .set SRC, %rsi // Pointer to next source data .set DST, %rdx // Pointer to next destination data -.set LEN, %rcx // Remaining length in bytes +.set LEN, %ecx // Remaining length in bytes +.set LEN8, %cl +.set LEN64, %rcx .set TWEAK, %r8 // Pointer to next tweak -// %r9 holds the AES key length in bytes. -.set KEYLEN, %r9d -.set KEYLEN64, %r9 +// %rax holds the AES key length in bytes. +.set KEYLEN, %eax +.set KEYLEN64, %rax -// %rax and %r10-r11 are available as temporaries. +// %r9-r11 are available as temporaries. .macro _define_Vi i .if VL == 16 @@ -565,9 +567,9 @@ // subtracting 16 from LEN. This is needed because ciphertext stealing // decryption uses the last two tweaks in reverse order. We'll handle // the last full block and the partial block specially at the end. - lea -16(LEN), %rax - test $15, LEN - cmovnz %rax, LEN + lea -16(LEN), %eax + test $15, LEN8 + cmovnz %eax, LEN .endif // Load the AES key length: 16 (AES-128), 24 (AES-192), or 32 (AES-256). @@ -650,7 +652,7 @@ // Check for the uncommon case where the data length isn't a multiple of // 4*VL. Handle it out-of-line in order to optimize for the common // case. In the common case, just fall through to the ret. - test $4*VL-1, LEN + test $4*VL-1, LEN8 jnz .Lhandle_remainder\@ .Ldone\@: // Store the next tweak back to *TWEAK to support continuation calls. @@ -718,9 +720,9 @@ .if USE_AVX10 // Create a mask that has the first LEN bits set. - mov $-1, %rax - bzhi LEN, %rax, %rax - kmovq %rax, %k1 + mov $-1, %r9d + bzhi LEN, %r9d, %r9d + kmovd %r9d, %k1 // Swap the first LEN bytes of the en/decryption of the last full block // with the partial block. Note that to support in-place en/decryption, @@ -730,23 +732,23 @@ vmovdqu8 16(SRC), %xmm0{%k1} vmovdqu8 %xmm1, 16(DST){%k1} .else - lea .Lcts_permute_table(%rip), %rax + lea .Lcts_permute_table(%rip), %r9 // Load the src partial block, left-aligned. Note that to support // in-place en/decryption, this must happen before the store to the dst // partial block. - vmovdqu (SRC, LEN, 1), %xmm1 + vmovdqu (SRC, LEN64, 1), %xmm1 // Shift the first LEN bytes of the en/decryption of the last full block // to the end of a register, then store it to DST+LEN. This stores the // dst partial block. It also writes to the second part of the dst last // full block, but that part is overwritten later. - vpshufb (%rax, LEN, 1), %xmm0, %xmm2 - vmovdqu %xmm2, (DST, LEN, 1) + vpshufb (%r9, LEN64, 1), %xmm0, %xmm2 + vmovdqu %xmm2, (DST, LEN64, 1) // Make xmm3 contain [16-LEN,16-LEN+1,...,14,15,0x80,0x80,...]. - sub LEN, %rax - vmovdqu 32(%rax), %xmm3 + sub LEN64, %r9 + vmovdqu 32(%r9), %xmm3 // Shift the src partial block to the beginning of its register. vpshufb %xmm3, %xmm1, %xmm1 @@ -795,7 +797,7 @@ SYM_FUNC_END(aes_xts_encrypt_iv) // instantiated from the above macro. They all have the following prototype: // // void (*xts_asm_func)(const struct crypto_aes_ctx *key, -// const u8 *src, u8 *dst, size_t len, +// const u8 *src, u8 *dst, unsigned int len, // u8 tweak[AES_BLOCK_SIZE]); // // |key| is the data key. |tweak| contains the next tweak; the encryption of diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index e7d21000cb05d..110b3282a1f27 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -899,7 +899,7 @@ static int xts_setkey_aesni(struct crypto_skcipher *tfm, const u8 *key, typedef void (*xts_encrypt_iv_func)(const struct crypto_aes_ctx *tweak_key, u8 iv[AES_BLOCK_SIZE]); typedef void (*xts_crypt_func)(const struct crypto_aes_ctx *key, - const u8 *src, u8 *dst, size_t len, + const u8 *src, u8 *dst, unsigned int len, u8 tweak[AES_BLOCK_SIZE]); /* This handles cases where the source and/or destination span pages. */ @@ -1021,14 +1021,14 @@ static void aesni_xts_encrypt_iv(const struct crypto_aes_ctx *tweak_key, } static void aesni_xts_encrypt(const struct crypto_aes_ctx *key, - const u8 *src, u8 *dst, size_t len, + const u8 *src, u8 *dst, unsigned int len, u8 tweak[AES_BLOCK_SIZE]) { aesni_xts_enc(key, dst, src, len, tweak); } static void aesni_xts_decrypt(const struct crypto_aes_ctx *key, - const u8 *src, u8 *dst, size_t len, + const u8 *src, u8 *dst, unsigned int len, u8 tweak[AES_BLOCK_SIZE]) { aesni_xts_dec(key, dst, src, len, tweak); @@ -1185,12 +1185,12 @@ asmlinkage void aes_xts_encrypt_iv(const struct crypto_aes_ctx *tweak_key, #define DEFINE_XTS_ALG(suffix, driver_name, priority) \ \ -asmlinkage void aes_xts_encrypt_##suffix(const struct crypto_aes_ctx *key, \ - const u8 *src, u8 *dst, size_t len, \ - u8 tweak[AES_BLOCK_SIZE]); \ -asmlinkage void aes_xts_decrypt_##suffix(const struct crypto_aes_ctx *key, \ - const u8 *src, u8 *dst, size_t len, \ - u8 tweak[AES_BLOCK_SIZE]); \ +asmlinkage void \ +aes_xts_encrypt_##suffix(const struct crypto_aes_ctx *key, const u8 *src, \ + u8 *dst, unsigned int len, u8 tweak[AES_BLOCK_SIZE]); \ +asmlinkage void \ +aes_xts_decrypt_##suffix(const struct crypto_aes_ctx *key, const u8 *src, \ + u8 *dst, unsigned int len, u8 tweak[AES_BLOCK_SIZE]); \ \ static int xts_encrypt_##suffix(struct skcipher_request *req) \ { \ -- cgit 1.2.3-korg