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authorSebastian Capella <sebastian.capella@linaro.org>2014-03-25 01:20:29 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-04-23 01:24:14 +0100
commit603fb42a66499ab353466c7afa3d38beea20a8a9 (patch)
tree14fd0f62deb8efe86340c528ddf5abc8289630fa
parent44ae903b96b1e5f9ff3103cd86918619c188003f (diff)
ARM: 8011/1: ARM hibernation / suspend-to-disk
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. Acked-by: Russ Dill <Russ.Dill@ti.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Sebastian Capella <sebastian.capella@linaro.org> Acked-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> [fixed duplicate virt_to_pfn() definition --rmk] Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/Kconfig5
-rw-r--r--arch/arm/kernel/Makefile1
-rw-r--r--arch/arm/kernel/hibernate.c107
-rw-r--r--include/linux/suspend.h2
4 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ab438cb5af55..58506175a3ea 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2294,6 +2294,11 @@ config ARCH_SUSPEND_POSSIBLE
config ARM_CPU_SUSPEND
def_bool PM_SLEEP
+config ARCH_HIBERNATION_POSSIBLE
+ bool
+ depends on MMU
+ default y if ARCH_SUSPEND_POSSIBLE
+
endmenu
source "net/Kconfig"
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index a766bcbaf8ad..10f0464206a2 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 000000000000..bb8b79648643
--- /dev/null
+++ b/arch/arm/kernel/hibernate.c
@@ -0,0 +1,107 @@
+/*
+ * 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 <rjw@sisk.pl>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/mm.h>
+#include <linux/suspend.h>
+#include <asm/system_misc.h>
+#include <asm/idmap.h>
+#include <asm/suspend.h>
+#include <asm/memory.h>
+
+extern const void __nosave_begin, __nosave_end;
+
+int pfn_is_nosave(unsigned long pfn)
+{
+ unsigned long nosave_begin_pfn = virt_to_pfn(&__nosave_begin);
+ unsigned long nosave_end_pfn = virt_to_pfn(&__nosave_end - 1);
+
+ 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 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, arch_save_image);
+}
+
+/*
+ * Restore page contents for physical pages that were in use during loading
+ * hibernation image. Switch to idmap_pgd so the physical page tables
+ * are overwritten with the same contents.
+ */
+static void notrace 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 u64 resume_stack[PAGE_SIZE/2/sizeof(u64)] __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(arch_restore_image, 0,
+ resume_stack + ARRAY_SIZE(resume_stack));
+ return 0;
+}
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index f73cabf59012..38bbf95109da 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) {}