From: Ard Biesheuvel <ard.biesheuvel@linaro.org> To: linux-crypto@vger.kernel.org Cc: Mark Rutland <mark.rutland@arm.com>, herbert@gondor.apana.org.au, Ard Biesheuvel <ard.biesheuvel@linaro.org>, Peter Zijlstra <peterz@infradead.org>, Catalin Marinas <catalin.marinas@arm.com>, Sebastian Andrzej Siewior <bigeasy@linutronix.de>, Will Deacon <will.deacon@arm.com>, Russell King - ARM Linux <linux@armlinux.org.uk>, Steven Rostedt <rostedt@goodmis.org>, Thomas Gleixner <tglx@linutronix.de>, Dave Martin <Dave.Martin@arm.com>, linux-arm-kernel@lists.infradead.org, linux-rt-users@vger.kernel.org Subject: [PATCH v5 05/23] crypto: arm64/chacha20 - move kernel mode neon en/disable into loop Date: Sat, 10 Mar 2018 15:21:50 +0000 [thread overview] Message-ID: <20180310152208.10369-6-ard.biesheuvel@linaro.org> (raw) In-Reply-To: <20180310152208.10369-1-ard.biesheuvel@linaro.org> When kernel mode NEON was first introduced on arm64, the preserve and restore of the userland NEON state was completely unoptimized, and involved saving all registers on each call to kernel_neon_begin(), and restoring them on each call to kernel_neon_end(). For this reason, the NEON crypto code that was introduced at the time keeps the NEON enabled throughout the execution of the crypto API methods, which may include calls back into the crypto API that could result in memory allocation or other actions that we should avoid when running with preemption disabled. Since then, we have optimized the kernel mode NEON handling, which now restores lazily (upon return to userland), and so the preserve action is only costly the first time it is called after entering the kernel. So let's put the kernel_neon_begin() and kernel_neon_end() calls around the actual invocations of the NEON crypto code, and run the remainder of the code with kernel mode NEON disabled (and preemption enabled) Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/crypto/chacha20-neon-glue.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/arm64/crypto/chacha20-neon-glue.c b/arch/arm64/crypto/chacha20-neon-glue.c index cbdb75d15cd0..727579c93ded 100644 --- a/arch/arm64/crypto/chacha20-neon-glue.c +++ b/arch/arm64/crypto/chacha20-neon-glue.c @@ -37,12 +37,19 @@ static void chacha20_doneon(u32 *state, u8 *dst, const u8 *src, u8 buf[CHACHA20_BLOCK_SIZE]; while (bytes >= CHACHA20_BLOCK_SIZE * 4) { + kernel_neon_begin(); chacha20_4block_xor_neon(state, dst, src); + kernel_neon_end(); bytes -= CHACHA20_BLOCK_SIZE * 4; src += CHACHA20_BLOCK_SIZE * 4; dst += CHACHA20_BLOCK_SIZE * 4; state[12] += 4; } + + if (!bytes) + return; + + kernel_neon_begin(); while (bytes >= CHACHA20_BLOCK_SIZE) { chacha20_block_xor_neon(state, dst, src); bytes -= CHACHA20_BLOCK_SIZE; @@ -55,6 +62,7 @@ static void chacha20_doneon(u32 *state, u8 *dst, const u8 *src, chacha20_block_xor_neon(state, buf, buf); memcpy(dst, buf, bytes); } + kernel_neon_end(); } static int chacha20_neon(struct skcipher_request *req) @@ -68,11 +76,10 @@ static int chacha20_neon(struct skcipher_request *req) if (!may_use_simd() || req->cryptlen <= CHACHA20_BLOCK_SIZE) return crypto_chacha20_crypt(req); - err = skcipher_walk_virt(&walk, req, true); + err = skcipher_walk_virt(&walk, req, false); crypto_chacha20_init(state, ctx, walk.iv); - kernel_neon_begin(); while (walk.nbytes > 0) { unsigned int nbytes = walk.nbytes; @@ -83,7 +90,6 @@ static int chacha20_neon(struct skcipher_request *req) nbytes); err = skcipher_walk_done(&walk, walk.nbytes - nbytes); } - kernel_neon_end(); return err; } -- 2.15.1
WARNING: multiple messages have this Message-ID (diff)
From: ard.biesheuvel@linaro.org (Ard Biesheuvel) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 05/23] crypto: arm64/chacha20 - move kernel mode neon en/disable into loop Date: Sat, 10 Mar 2018 15:21:50 +0000 [thread overview] Message-ID: <20180310152208.10369-6-ard.biesheuvel@linaro.org> (raw) In-Reply-To: <20180310152208.10369-1-ard.biesheuvel@linaro.org> When kernel mode NEON was first introduced on arm64, the preserve and restore of the userland NEON state was completely unoptimized, and involved saving all registers on each call to kernel_neon_begin(), and restoring them on each call to kernel_neon_end(). For this reason, the NEON crypto code that was introduced at the time keeps the NEON enabled throughout the execution of the crypto API methods, which may include calls back into the crypto API that could result in memory allocation or other actions that we should avoid when running with preemption disabled. Since then, we have optimized the kernel mode NEON handling, which now restores lazily (upon return to userland), and so the preserve action is only costly the first time it is called after entering the kernel. So let's put the kernel_neon_begin() and kernel_neon_end() calls around the actual invocations of the NEON crypto code, and run the remainder of the code with kernel mode NEON disabled (and preemption enabled) Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/crypto/chacha20-neon-glue.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/arm64/crypto/chacha20-neon-glue.c b/arch/arm64/crypto/chacha20-neon-glue.c index cbdb75d15cd0..727579c93ded 100644 --- a/arch/arm64/crypto/chacha20-neon-glue.c +++ b/arch/arm64/crypto/chacha20-neon-glue.c @@ -37,12 +37,19 @@ static void chacha20_doneon(u32 *state, u8 *dst, const u8 *src, u8 buf[CHACHA20_BLOCK_SIZE]; while (bytes >= CHACHA20_BLOCK_SIZE * 4) { + kernel_neon_begin(); chacha20_4block_xor_neon(state, dst, src); + kernel_neon_end(); bytes -= CHACHA20_BLOCK_SIZE * 4; src += CHACHA20_BLOCK_SIZE * 4; dst += CHACHA20_BLOCK_SIZE * 4; state[12] += 4; } + + if (!bytes) + return; + + kernel_neon_begin(); while (bytes >= CHACHA20_BLOCK_SIZE) { chacha20_block_xor_neon(state, dst, src); bytes -= CHACHA20_BLOCK_SIZE; @@ -55,6 +62,7 @@ static void chacha20_doneon(u32 *state, u8 *dst, const u8 *src, chacha20_block_xor_neon(state, buf, buf); memcpy(dst, buf, bytes); } + kernel_neon_end(); } static int chacha20_neon(struct skcipher_request *req) @@ -68,11 +76,10 @@ static int chacha20_neon(struct skcipher_request *req) if (!may_use_simd() || req->cryptlen <= CHACHA20_BLOCK_SIZE) return crypto_chacha20_crypt(req); - err = skcipher_walk_virt(&walk, req, true); + err = skcipher_walk_virt(&walk, req, false); crypto_chacha20_init(state, ctx, walk.iv); - kernel_neon_begin(); while (walk.nbytes > 0) { unsigned int nbytes = walk.nbytes; @@ -83,7 +90,6 @@ static int chacha20_neon(struct skcipher_request *req) nbytes); err = skcipher_walk_done(&walk, walk.nbytes - nbytes); } - kernel_neon_end(); return err; } -- 2.15.1
next prev parent reply other threads:[~2018-03-10 15:21 UTC|newest] Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-03-10 15:21 [PATCH v5 00/23] crypto: arm64 - play nice with CONFIG_PREEMPT Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 01/23] crypto: testmgr - add a new test case for CRC-T10DIF Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 02/23] crypto: arm64/aes-ce-ccm - move kernel mode neon en/disable into loop Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 03/23] crypto: arm64/aes-blk " Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 04/23] crypto: arm64/aes-bs " Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel [this message] 2018-03-10 15:21 ` [PATCH v5 05/23] crypto: arm64/chacha20 " Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 06/23] crypto: arm64/aes-blk - remove configurable interleave Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 07/23] crypto: arm64/aes-blk - add 4 way interleave to CBC encrypt path Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 08/23] crypto: arm64/aes-blk - add 4 way interleave to CBC-MAC " Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 09/23] crypto: arm64/sha256-neon - play nice with CONFIG_PREEMPT kernels Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 10/23] arm64: assembler: add utility macros to push/pop stack frames Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 11/23] arm64: assembler: add macros to conditionally yield the NEON under PREEMPT Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 12/23] crypto: arm64/sha1-ce - yield NEON after every block of input Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 13/23] crypto: arm64/sha2-ce " Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:21 ` [PATCH v5 14/23] crypto: arm64/aes-ccm " Ard Biesheuvel 2018-03-10 15:21 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 15/23] crypto: arm64/aes-blk " Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 16/23] crypto: arm64/aes-bs " Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 17/23] crypto: arm64/aes-ghash " Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 18/23] crypto: arm64/crc32-ce " Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 19/23] crypto: arm64/crct10dif-ce " Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 20/23] crypto: arm64/sha3-ce " Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 21/23] crypto: arm64/sha512-ce " Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 22/23] crypto: arm64/sm3-ce " Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-10 15:22 ` [PATCH v5 23/23] DO NOT MERGE Ard Biesheuvel 2018-03-10 15:22 ` Ard Biesheuvel 2018-03-11 5:16 ` [PATCH v5 00/23] crypto: arm64 - play nice with CONFIG_PREEMPT Vakul Garg 2018-03-11 5:16 ` Vakul Garg 2018-03-11 8:55 ` Ard Biesheuvel 2018-03-11 8:55 ` Ard Biesheuvel 2018-03-16 15:57 ` Herbert Xu 2018-03-16 15:57 ` Herbert Xu 2018-03-19 15:31 ` Ard Biesheuvel 2018-03-19 15:31 ` Ard Biesheuvel 2018-03-19 23:36 ` Herbert Xu 2018-03-19 23:36 ` Herbert Xu
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