Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754278Ab3EFOvc (ORCPT ); Mon, 6 May 2013 10:51:32 -0400 Received: from smtp.citrix.com ([66.165.176.89]:14561 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753717Ab3EFOva (ORCPT ); Mon, 6 May 2013 10:51:30 -0400 X-IronPort-AV: E=Sophos;i="4.87,622,1363132800"; d="scan'208";a="23502644" From: Stefano Stabellini To: CC: , , , , , , Stefano Stabellini , , , , , Subject: [PATCH RFC v2 2/4] arm: introduce CONFIG_PARAVIRT and pv_time_ops Date: Mon, 6 May 2013 15:51:16 +0100 Message-ID: <1367851878-21629-2-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3945 Lines: 134 Introduce CONFIG_PARAVIRT on ARM. The only paravirt interface supported is pv_time_ops.steal_clock. No runtime pvops patching yet. This allows us to make us of steal_account_process_tick for stolen ticks accounting. Signed-off-by: Stefano Stabellini CC: linux@arm.linux.org.uk CC: will.deacon@arm.com CC: nico@linaro.org CC: marc.zyngier@arm.com CC: cov@codeaurora.org CC: arnd@arndb.de CC: olof@lixom.net --- arch/arm/Kconfig | 9 +++++++++ arch/arm/include/asm/paravirt.h | 19 +++++++++++++++++++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/paravirt.c | 32 ++++++++++++++++++++++++++++++++ 4 files changed, 61 insertions(+), 0 deletions(-) create mode 100644 arch/arm/include/asm/paravirt.h create mode 100644 arch/arm/kernel/paravirt.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 344e299..35cb10a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1887,12 +1887,21 @@ config XEN_DOM0 def_bool y depends on XEN +config PARAVIRT + bool "Enable paravirtualization code" + ---help--- + This changes the kernel so it can modify itself when it is run + under a hypervisor, potentially improving performance significantly + over full virtualization. However, when run without a hypervisor + the kernel is theoretically slower and slightly larger. + config XEN bool "Xen guest support on ARM (EXPERIMENTAL)" depends on ARM && AEABI && OF depends on CPU_V7 && !CPU_V6 depends on !GENERIC_ATOMIC64 select ARM_PSCI + select PARAVIRT help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM. diff --git a/arch/arm/include/asm/paravirt.h b/arch/arm/include/asm/paravirt.h new file mode 100644 index 0000000..3b95bc6 --- /dev/null +++ b/arch/arm/include/asm/paravirt.h @@ -0,0 +1,19 @@ +#ifndef _ASM_ARM_PARAVIRT_H +#define _ASM_ARM_PARAVIRT_H + +struct static_key; +extern struct static_key paravirt_steal_enabled; +extern struct static_key paravirt_steal_rq_enabled; + +struct pv_time_ops { + unsigned long long (*steal_clock)(int cpu); +}; +extern struct pv_time_ops pv_time_ops; + +static inline u64 paravirt_steal_clock(int cpu) +{ + return pv_time_ops.steal_clock(cpu); +} + + +#endif diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index dd9d90a..6764f60 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -86,5 +86,6 @@ ifeq ($(CONFIG_ARM_PSCI),y) obj-y += psci.o obj-$(CONFIG_SMP) += psci_smp.o endif +obj-$(CONFIG_PARAVIRT) += paravirt.o extra-y := $(head-y) vmlinux.lds diff --git a/arch/arm/kernel/paravirt.c b/arch/arm/kernel/paravirt.c new file mode 100644 index 0000000..3e73fc8 --- /dev/null +++ b/arch/arm/kernel/paravirt.c @@ -0,0 +1,32 @@ +/* + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2013 Citrix Systems + * + * Author: Stefano Stabellini + */ + +#include +#include +#include +#include + +struct static_key paravirt_steal_enabled; +struct static_key paravirt_steal_rq_enabled; + +static u64 native_steal_clock(int cpu) +{ + return 0; +} + +struct pv_time_ops pv_time_ops = { + .steal_clock = native_steal_clock, +}; +EXPORT_SYMBOL_GPL(pv_time_ops); -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/