From: Huang Ying Subject: [PATCH -v3] x86: Move kernel_fpu_using to irq_fpu_usable in asm/i387.h Date: Mon, 31 Aug 2009 13:11:54 +0800 Message-ID: <1251695514.14648.344.camel@yhuang-dev.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Herbert Xu , "linux-kernel@vger.kernel.org" , "linux-crypto@vger.kernel.org" To: "H. Peter Anvin" Return-path: Received: from mga01.intel.com ([192.55.52.88]:48641 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752900AbZHaFL4 (ORCPT ); Mon, 31 Aug 2009 01:11:56 -0400 Sender: linux-crypto-owner@vger.kernel.org List-ID: This function measures whether the FPU/SSE state can be touched in interrupt context. If the interrupted code is in user space or has no valid FPU/SSE context (CR0.TS == 1), FPU/SSE state can be used in IRQ or soft_irq context too. This is used by AES-NI accelerated AES implementation and PCLMULQDQ accelerated GHASH implementation. v3: - Renamed to irq_fpu_usable to reflect the purpose of the function. v2: - Renamed to irq_is_fpu_using to reflect the real situation. Signed-off-by: Huang Ying CC: H. Peter Anvin --- arch/x86/crypto/aesni-intel_glue.c | 17 +++++------------ arch/x86/include/asm/i387.h | 8 ++++++++ 2 files changed, 13 insertions(+), 12 deletions(-) --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -59,13 +59,6 @@ asmlinkage void aesni_cbc_enc(struct cry asmlinkage void aesni_cbc_dec(struct crypto_aes_ctx *ctx, u8 *out, const u8 *in, unsigned int len, u8 *iv); -static inline int kernel_fpu_using(void) -{ - if (in_interrupt() && !(read_cr0() & X86_CR0_TS)) - return 1; - return 0; -} - static inline struct crypto_aes_ctx *aes_ctx(void *raw_ctx) { unsigned long addr = (unsigned long)raw_ctx; @@ -89,7 +82,7 @@ static int aes_set_key_common(struct cry return -EINVAL; } - if (kernel_fpu_using()) + if (irq_fpu_usable()) err = crypto_aes_expand_key(ctx, in_key, key_len); else { kernel_fpu_begin(); @@ -110,7 +103,7 @@ static void aes_encrypt(struct crypto_tf { struct crypto_aes_ctx *ctx = aes_ctx(crypto_tfm_ctx(tfm)); - if (kernel_fpu_using()) + if (irq_fpu_usable()) crypto_aes_encrypt_x86(ctx, dst, src); else { kernel_fpu_begin(); @@ -123,7 +116,7 @@ static void aes_decrypt(struct crypto_tf { struct crypto_aes_ctx *ctx = aes_ctx(crypto_tfm_ctx(tfm)); - if (kernel_fpu_using()) + if (irq_fpu_usable()) crypto_aes_decrypt_x86(ctx, dst, src); else { kernel_fpu_begin(); @@ -349,7 +342,7 @@ static int ablk_encrypt(struct ablkciphe struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req); struct async_aes_ctx *ctx = crypto_ablkcipher_ctx(tfm); - if (kernel_fpu_using()) { + if (irq_fpu_usable()) { struct ablkcipher_request *cryptd_req = ablkcipher_request_ctx(req); memcpy(cryptd_req, req, sizeof(*req)); @@ -370,7 +363,7 @@ static int ablk_decrypt(struct ablkciphe struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req); struct async_aes_ctx *ctx = crypto_ablkcipher_ctx(tfm); - if (kernel_fpu_using()) { + if (irq_fpu_usable()) { struct ablkcipher_request *cryptd_req = ablkcipher_request_ctx(req); memcpy(cryptd_req, req, sizeof(*req)); --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -301,6 +301,14 @@ static inline void kernel_fpu_end(void) preempt_enable(); } +static inline bool irq_fpu_usable(void) +{ + struct pt_regs *regs; + + return !in_interrupt() || !(regs = get_irq_regs()) || \ + user_mode(regs) || (read_cr0() & X86_CR0_TS); +} + /* * Some instructions like VIA's padlock instructions generate a spurious * DNA fault but don't modify SSE registers. And these instructions