From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753222AbaA2Qvn (ORCPT ); Wed, 29 Jan 2014 11:51:43 -0500 Received: from mail-ea0-f174.google.com ([209.85.215.174]:41637 "EHLO mail-ea0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752634AbaA2Qvk (ORCPT ); Wed, 29 Jan 2014 11:51:40 -0500 From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: catalin.marinas@arm.com, will.deacon@arm.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, Ard Biesheuvel Subject: [PATCH 4/5] arm64: enable generic CPU feature modalias matching for this arch Date: Wed, 29 Jan 2014 17:50:45 +0100 Message-Id: <1391014246-9715-5-git-send-email-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1391014246-9715-1-git-send-email-ard.biesheuvel@linaro.org> References: <1391014246-9715-1-git-send-email-ard.biesheuvel@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This enables support for the generic CPU feature modalias implementation that wires up optional CPU features to udev based module autoprobing. A file is provided that maps CPU feature numbers to elf_hwcap bits, which is the standard way on arm64 to advertise optional CPU features both internally and to user space. Signed-off-by: Ard Biesheuvel --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/cpufeature.h | 30 ++++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) create mode 100644 arch/arm64/include/asm/cpufeature.h diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index dd4327f09ba4..e339099b6fbd 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -16,6 +16,7 @@ config ARM64 select DCACHE_WORD_ACCESS select GENERIC_CLOCKEVENTS select GENERIC_CLOCKEVENTS_BROADCAST if SMP + select GENERIC_CPU_AUTOPROBE select GENERIC_IOMAP select GENERIC_IRQ_PROBE select GENERIC_IRQ_SHOW diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h new file mode 100644 index 000000000000..1d902efa201d --- /dev/null +++ b/arch/arm64/include/asm/cpufeature.h @@ -0,0 +1,30 @@ +/* + * Copyright (C) 2014 Linaro Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __ASM_CPUFEATURE_H +#define __ASM_CPUFEATURE_H + +#include +#include + +/* + * In the arm64 world (as in the ARM world), elf_hwcap is used both internally + * in the kernel and for user space to keep track of which optional features + * are supported by the current system. So let's map feature 'x' to HWCAP_x. + * Note that HWCAP_x constants are bit fields so we need to take the log. + */ + +#define MAX_CPU_FEATURES sizeof(elf_hwcap) +#define cpu_feature(x) ((unsigned int)ilog2(HWCAP_ ## x)) + +static inline bool cpu_have_feature(unsigned int num) +{ + return !!(elf_hwcap & (1 << num)); +} + +#endif -- 1.8.3.2