From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753174AbdLAOSf (ORCPT ); Fri, 1 Dec 2017 09:18:35 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:41524 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752772AbdLAOSd (ORCPT ); Fri, 1 Dec 2017 09:18:33 -0500 Date: Fri, 1 Dec 2017 14:18:28 +0000 From: Mark Rutland To: Sebastian Andrzej Siewior Cc: linux-rt-users@vger.kernel.org, Peter Zijlstra , Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, Steven Rostedt , tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, ard.biesheuvel@linaro.org Subject: Re: [PATCH RT] arm*: disable NEON in kernel mode Message-ID: <20171201141827.yip6pl3tt7kxzek7@lakrids.cambridge.arm.com> References: <20171130142216.GB12606@linutronix.de> <20171130143028.GA1351@linutronix.de> <20171201104331.GB1612@linutronix.de> <20171201134506.GF1612@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171201134506.GF1612@linutronix.de> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Adding Ard, who wrote the NEON crypto code] On Fri, Dec 01, 2017 at 02:45:06PM +0100, Sebastian Andrzej Siewior wrote: > +arm folks, to let you know > > On 2017-12-01 11:43:32 [+0100], To linux-rt-users@vger.kernel.org wrote: > > NEON in kernel mode is used by the crypto algorithms and raid6 code. > > While the raid6 code looks okay, the crypto algorithms do not: NEON > > is enabled on first invocation and may allocate/free/map memory before > > the NEON mode is disabled again. Could you elaborate on why this is a problem? I guess this is because kernel_neon_{begin,end}() disable preemption? ... is this specific to RT? Thanks, Mark. > > This needs to be changed until it can be enabled. > > On ARM NEON in kernel mode can be simply disabled. on ARM64 it needs to > > stay on due to possible EFI callbacks so here I disable each algorithm. > > > > Cc: stable-rt@vger.kernel.org > > Signed-off-by: Sebastian Andrzej Siewior > > --- > > arch/arm/Kconfig | 2 +- > > arch/arm64/crypto/Kconfig | 20 ++++++++++---------- > > arch/arm64/crypto/crc32-ce-glue.c | 3 ++- > > 3 files changed, 13 insertions(+), 12 deletions(-) > > > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > > index d1346a160760..914fecb088a8 100644 > > --- a/arch/arm/Kconfig > > +++ b/arch/arm/Kconfig > > @@ -2164,7 +2164,7 @@ config NEON > > > > config KERNEL_MODE_NEON > > bool "Support for NEON in kernel mode" > > - depends on NEON && AEABI > > + depends on NEON && AEABI && !PREEMPT_RT_BASE > > help > > Say Y to include support for NEON in kernel mode. > > > > diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig > > index 70c517aa4501..2a5f05b5a19a 100644 > > --- a/arch/arm64/crypto/Kconfig > > +++ b/arch/arm64/crypto/Kconfig > > @@ -19,19 +19,19 @@ config CRYPTO_SHA512_ARM64 > > > > config CRYPTO_SHA1_ARM64_CE > > tristate "SHA-1 digest algorithm (ARMv8 Crypto Extensions)" > > - depends on KERNEL_MODE_NEON > > + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_HASH > > select CRYPTO_SHA1 > > > > config CRYPTO_SHA2_ARM64_CE > > tristate "SHA-224/SHA-256 digest algorithm (ARMv8 Crypto Extensions)" > > - depends on KERNEL_MODE_NEON > > + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_HASH > > select CRYPTO_SHA256_ARM64 > > > > config CRYPTO_GHASH_ARM64_CE > > tristate "GHASH/AES-GCM using ARMv8 Crypto Extensions" > > - depends on KERNEL_MODE_NEON > > + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_HASH > > select CRYPTO_GF128MUL > > select CRYPTO_AES > > @@ -39,7 +39,7 @@ config CRYPTO_GHASH_ARM64_CE > > > > config CRYPTO_CRCT10DIF_ARM64_CE > > tristate "CRCT10DIF digest algorithm using PMULL instructions" > > - depends on KERNEL_MODE_NEON && CRC_T10DIF > > + depends on KERNEL_MODE_NEON && CRC_T10DIF && !PREEMPT_RT_BASE > > select CRYPTO_HASH > > > > config CRYPTO_CRC32_ARM64_CE > > @@ -53,13 +53,13 @@ config CRYPTO_AES_ARM64 > > > > config CRYPTO_AES_ARM64_CE > > tristate "AES core cipher using ARMv8 Crypto Extensions" > > - depends on ARM64 && KERNEL_MODE_NEON > > + depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_ALGAPI > > select CRYPTO_AES_ARM64 > > > > config CRYPTO_AES_ARM64_CE_CCM > > tristate "AES in CCM mode using ARMv8 Crypto Extensions" > > - depends on ARM64 && KERNEL_MODE_NEON > > + depends on ARM64 && KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_ALGAPI > > select CRYPTO_AES_ARM64_CE > > select CRYPTO_AES_ARM64 > > @@ -67,7 +67,7 @@ config CRYPTO_AES_ARM64_CE_CCM > > > > config CRYPTO_AES_ARM64_CE_BLK > > tristate "AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions" > > - depends on KERNEL_MODE_NEON > > + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_BLKCIPHER > > select CRYPTO_AES_ARM64_CE > > select CRYPTO_AES_ARM64 > > @@ -75,7 +75,7 @@ config CRYPTO_AES_ARM64_CE_BLK > > > > config CRYPTO_AES_ARM64_NEON_BLK > > tristate "AES in ECB/CBC/CTR/XTS modes using NEON instructions" > > - depends on KERNEL_MODE_NEON > > + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_BLKCIPHER > > select CRYPTO_AES_ARM64 > > select CRYPTO_AES > > @@ -83,13 +83,13 @@ config CRYPTO_AES_ARM64_NEON_BLK > > > > config CRYPTO_CHACHA20_NEON > > tristate "NEON accelerated ChaCha20 symmetric cipher" > > - depends on KERNEL_MODE_NEON > > + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_BLKCIPHER > > select CRYPTO_CHACHA20 > > > > config CRYPTO_AES_ARM64_BS > > tristate "AES in ECB/CBC/CTR/XTS modes using bit-sliced NEON algorithm" > > - depends on KERNEL_MODE_NEON > > + depends on KERNEL_MODE_NEON && !PREEMPT_RT_BASE > > select CRYPTO_BLKCIPHER > > select CRYPTO_AES_ARM64_NEON_BLK > > select CRYPTO_AES_ARM64 > > diff --git a/arch/arm64/crypto/crc32-ce-glue.c b/arch/arm64/crypto/crc32-ce-glue.c > > index 624f4137918c..599de95cd86d 100644 > > --- a/arch/arm64/crypto/crc32-ce-glue.c > > +++ b/arch/arm64/crypto/crc32-ce-glue.c > > @@ -206,7 +206,8 @@ static struct shash_alg crc32_pmull_algs[] = { { > > > > static int __init crc32_pmull_mod_init(void) > > { > > - if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_PMULL)) { > > + if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && > > + !IS_ENABLED(CONFIG_PREEMPT_RT_BASE) && (elf_hwcap & HWCAP_PMULL)) { > > crc32_pmull_algs[0].update = crc32_pmull_update; > > crc32_pmull_algs[1].update = crc32c_pmull_update; > > > > -- > > 2.15.0 > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel