Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753873AbaBZTTQ (ORCPT ); Wed, 26 Feb 2014 14:19:16 -0500 Received: from devils.ext.ti.com ([198.47.26.153]:51332 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752658AbaBZTTO (ORCPT ); Wed, 26 Feb 2014 14:19:14 -0500 Message-ID: <530E3DF5.8000309@ti.com> Date: Wed, 26 Feb 2014 11:18:13 -0800 From: Russ Dill Organization: Texas Instruments User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Sebastian Capella , , , , CC: "Rafael J. Wysocki" , Russell King , Len Brown , Pavel Machek , Nicolas Pitre , Santosh Shilimkar , Will Deacon , Jonathan Austin , Catalin Marinas , =?UTF-8?B?VXdlIEtsZWluZS1Lw7ZuaWc=?= , Stephen Boyd , Lorenzo Pieralisi Subject: Re: [PATCH v4 2/2] ARM hibernation / suspend-to-disk References: <1393441857-15472-1-git-send-email-sebastian.capella@linaro.org> <1393441857-15472-3-git-send-email-sebastian.capella@linaro.org> In-Reply-To: <1393441857-15472-3-git-send-email-sebastian.capella@linaro.org> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/26/2014 11:10 AM, Sebastian Capella wrote: > From: Russ Dill > > Enable hibernation for ARM architectures and provide ARM > architecture specific calls used during hibernation. > > The swsusp hibernation framework depends on the > platform first having functional suspend/resume. > > Then, in order to enable hibernation on a given platform, a > platform_hibernation_ops structure may need to be registered with > the system in order to save/restore any SoC-specific / cpu specific > state needing (re)init over a suspend-to-disk/resume-from-disk cycle. > > For example: > > - "secure" SoCs that have different sets of control registers > and/or different CR reg access patterns. > > - SoCs with L2 caches as the activation sequence there is > SoC-dependent; a full off-on cycle for L2 is not done > by the hibernation support code. > > - SoCs requiring steps on wakeup _before_ the "generic" parts > done by cpu_suspend / cpu_resume can work correctly. > > - SoCs having persistent state which is maintained during suspend > and resume, but will be lost during the power off cycle after > suspend-to-disk. > > This is a rebase/rework of Frank Hofmann's v5 hibernation patchset. > > Cc: Russ Dill > Cc: "Rafael J. Wysocki" > Signed-off-by: Sebastian Capella > Cc: Russell King > Cc: Len Brown > Cc: Pavel Machek > Cc: Nicolas Pitre > Cc: Santosh Shilimkar > Cc: Will Deacon > Cc: Jonathan Austin > Cc: Catalin Marinas > Cc: "Uwe Kleine-König" > Cc: Stephen Boyd > Cc: Lorenzo Pieralisi Acked-by: Russ Dill > --- > arch/arm/include/asm/memory.h | 1 + > arch/arm/kernel/Makefile | 1 + > arch/arm/kernel/hibernate.c | 113 +++++++++++++++++++++++++++++++++++++++++ > arch/arm/mm/Kconfig | 5 ++ > include/linux/suspend.h | 2 + > 5 files changed, 122 insertions(+) > create mode 100644 arch/arm/kernel/hibernate.c > > diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h > index 8756e4b..1079ea8 100644 > --- a/arch/arm/include/asm/memory.h > +++ b/arch/arm/include/asm/memory.h > @@ -291,6 +291,7 @@ static inline void *phys_to_virt(phys_addr_t x) > */ > #define __pa(x) __virt_to_phys((unsigned long)(x)) > #define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x))) > +#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0)) > #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) > > extern phys_addr_t (*arch_virt_to_idmap)(unsigned long x); > diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile > index a30fc9b..8afa848 100644 > --- a/arch/arm/kernel/Makefile > +++ b/arch/arm/kernel/Makefile > @@ -39,6 +39,7 @@ obj-$(CONFIG_ARTHUR) += arthur.o > obj-$(CONFIG_ISA_DMA) += dma-isa.o > obj-$(CONFIG_PCI) += bios32.o isa.o > obj-$(CONFIG_ARM_CPU_SUSPEND) += sleep.o suspend.o > +obj-$(CONFIG_HIBERNATION) += hibernate.o > obj-$(CONFIG_SMP) += smp.o > ifdef CONFIG_MMU > obj-$(CONFIG_SMP) += smp_tlb.o > diff --git a/arch/arm/kernel/hibernate.c b/arch/arm/kernel/hibernate.c > new file mode 100644 > index 0000000..70e17d2 > --- /dev/null > +++ b/arch/arm/kernel/hibernate.c > @@ -0,0 +1,113 @@ > +/* > + * Hibernation support specific for ARM > + * > + * Derived from work on ARM hibernation support by: > + * > + * Ubuntu project, hibernation support for mach-dove > + * Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu) > + * Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.) > + * https://lkml.org/lkml/2010/6/18/4 > + * https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/027422.html > + * https://patchwork.kernel.org/patch/96442/ > + * > + * Copyright (C) 2006 Rafael J. Wysocki > + * > + * License terms: GNU General Public License (GPL) version 2 > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +extern const void __nosave_begin, __nosave_end; > + > +int pfn_is_nosave(unsigned long pfn) > +{ > + unsigned long nosave_begin_pfn = > + __pa_symbol(&__nosave_begin) >> PAGE_SHIFT; > + unsigned long nosave_end_pfn = > + PAGE_ALIGN(__pa_symbol(&__nosave_end)) >> PAGE_SHIFT; > + > + return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); > +} > + > +void notrace save_processor_state(void) > +{ > + WARN_ON(num_online_cpus() != 1); > + local_fiq_disable(); > +} > + > +void notrace restore_processor_state(void) > +{ > + local_fiq_enable(); > +} > + > +/* > + * Snapshot kernel memory and reset the system. > + * > + * swsusp_save() is executed in the suspend finisher so that the CPU > + * context pointer and memory are part of the saved image, which is > + * required by the resume kernel image to restart execution from > + * swsusp_arch_suspend(). > + * > + * soft_restart is not technically needed, but is used to get success > + * returned from cpu_suspend. > + * > + * When soft reboot completes, the hibernation snapshot is written out. > + */ > +static int notrace __swsusp_arch_save_image(unsigned long unused) > +{ > + int ret; > + > + ret = swsusp_save(); > + if (ret == 0) > + soft_restart(virt_to_phys(cpu_resume)); > + return ret; > +} > + > +/* > + * Save the current CPU state before suspend / poweroff. > + */ > +int notrace swsusp_arch_suspend(void) > +{ > + return cpu_suspend(0, __swsusp_arch_save_image); > +} > + > +/* > + * The framework loads the hibernation image into a linked list anchored > + * at restore_pblist, for swsusp_arch_resume() to copy back to the proper > + * destinations. > + * > + * To make this work if resume is triggered from initramfs, the > + * pagetables need to be switched to allow writes to kernel mem. > + */ > +static void notrace __swsusp_arch_restore_image(void *unused) > +{ > + struct pbe *pbe; > + > + cpu_switch_mm(idmap_pgd, &init_mm); > + for (pbe = restore_pblist; pbe; pbe = pbe->next) > + copy_page(pbe->orig_address, pbe->address); > + > + soft_restart(virt_to_phys(cpu_resume)); > +} > + > +static u8 __swsusp_resume_stk[PAGE_SIZE/2] __nosavedata; > + > +/* > + * Resume from the hibernation image. > + * Due to the kernel heap / data restore, stack contents change underneath > + * and that would make function calls impossible; switch to a temporary > + * stack within the nosave region to avoid that problem. > + */ > +int swsusp_arch_resume(void) > +{ > + extern void call_with_stack(void (*fn)(void *), void *arg, void *sp); > + call_with_stack(__swsusp_arch_restore_image, 0, > + __swsusp_resume_stk + sizeof(__swsusp_resume_stk)); > + return 0; > +} > diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig > index 1f8fed9..83707702 100644 > --- a/arch/arm/mm/Kconfig > +++ b/arch/arm/mm/Kconfig > @@ -611,6 +611,11 @@ config CPU_USE_DOMAINS > config IO_36 > bool > > +config ARCH_HIBERNATION_POSSIBLE > + bool > + depends on MMU > + default y if CPU_ARM920T || CPU_ARM926T || CPU_SA1100 || CPU_XSCALE || CPU_XSC3 || CPU_V6 || CPU_V6K || CPU_V7 > + > comment "Processor Features" > > config ARM_LPAE > diff --git a/include/linux/suspend.h b/include/linux/suspend.h > index f73cabf..38bbf95 100644 > --- a/include/linux/suspend.h > +++ b/include/linux/suspend.h > @@ -320,6 +320,8 @@ extern unsigned long get_safe_page(gfp_t gfp_mask); > extern void hibernation_set_ops(const struct platform_hibernation_ops *ops); > extern int hibernate(void); > extern bool system_entering_hibernation(void); > +asmlinkage int swsusp_save(void); > +extern struct pbe *restore_pblist; > #else /* CONFIG_HIBERNATION */ > static inline void register_nosave_region(unsigned long b, unsigned long e) {} > static inline void register_nosave_region_late(unsigned long b, unsigned long e) {} > -- 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/