From 2ca6f62f595c01f689b269db6736de5544da7667 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 18 Apr 2011 23:58:59 +0200 Subject: PM: Fix error code paths executed after failing syscore_suspend() If syscore_suspend() fails in suspend_enter(), create_image() or resume_target_kernel(), it is necessary to call sysdev_resume(), because sysdev_suspend() has been called already and succeeded and we are going to abort the transition. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman --- kernel/power/hibernate.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index aeabd26e3342..50aae660174d 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -273,8 +273,11 @@ static int create_image(int platform_mode) local_irq_disable(); error = sysdev_suspend(PMSG_FREEZE); - if (!error) + if (!error) { error = syscore_suspend(); + if (error) + sysdev_resume(); + } if (error) { printk(KERN_ERR "PM: Some system devices failed to power down, " "aborting hibernation\n"); @@ -407,8 +410,11 @@ static int resume_target_kernel(bool platform_mode) local_irq_disable(); error = sysdev_suspend(PMSG_QUIESCE); - if (!error) + if (!error) { error = syscore_suspend(); + if (error) + sysdev_resume(); + } if (error) goto Enable_irqs; -- cgit v1.2.3 From 2e711c04dbbf7a7732a3f7073b1fc285d12b369d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 26 Apr 2011 19:15:07 +0200 Subject: PM: Remove sysdev suspend, resume and shutdown operations Since suspend, resume and shutdown operations in struct sysdev_class and struct sysdev_driver are not used any more, remove them. Also drop sysdev_suspend(), sysdev_resume() and sysdev_shutdown() used for executing those operations and modify all of their users accordingly. This reduces kernel code size quite a bit and reduces its complexity. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman --- arch/sh/Kconfig | 1 - arch/x86/Kconfig | 1 - arch/x86/kernel/apm_32.c | 4 - drivers/base/Kconfig | 7 -- drivers/base/base.h | 2 - drivers/base/sys.c | 202 +---------------------------------------------- drivers/xen/manage.c | 8 +- include/linux/device.h | 7 -- include/linux/pm.h | 8 -- include/linux/sysdev.h | 11 --- kernel/kexec.c | 9 +-- kernel/power/hibernate.c | 18 +---- kernel/power/suspend.c | 8 +- kernel/sys.c | 3 - 14 files changed, 7 insertions(+), 282 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index 4b89da248d17..bc439de48cd1 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -24,7 +24,6 @@ config SUPERH select RTC_LIB select GENERIC_ATOMIC64 select GENERIC_IRQ_SHOW - select ARCH_NO_SYSDEV_OPS help The SuperH is a RISC processor targeted for use in embedded systems and consumer electronics; it was also used in the Sega Dreamcast diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index cc6c53a95bfd..140e254fe546 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -71,7 +71,6 @@ config X86 select GENERIC_IRQ_SHOW select IRQ_FORCED_THREADING select USE_GENERIC_SMP_HELPERS if SMP - select ARCH_NO_SYSDEV_OPS config INSTRUCTION_DECODER def_bool (KPROBES || PERF_EVENTS) diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c index adee12e0da1f..3bfa02235965 100644 --- a/arch/x86/kernel/apm_32.c +++ b/arch/x86/kernel/apm_32.c @@ -1238,7 +1238,6 @@ static int suspend(int vetoable) dpm_suspend_noirq(PMSG_SUSPEND); local_irq_disable(); - sysdev_suspend(PMSG_SUSPEND); syscore_suspend(); local_irq_enable(); @@ -1258,7 +1257,6 @@ static int suspend(int vetoable) err = (err == APM_SUCCESS) ? 0 : -EIO; syscore_resume(); - sysdev_resume(); local_irq_enable(); dpm_resume_noirq(PMSG_RESUME); @@ -1282,7 +1280,6 @@ static void standby(void) dpm_suspend_noirq(PMSG_SUSPEND); local_irq_disable(); - sysdev_suspend(PMSG_SUSPEND); syscore_suspend(); local_irq_enable(); @@ -1292,7 +1289,6 @@ static void standby(void) local_irq_disable(); syscore_resume(); - sysdev_resume(); local_irq_enable(); dpm_resume_noirq(PMSG_RESUME); diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index e9e5238f3106..d57e8d0fb823 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -168,11 +168,4 @@ config SYS_HYPERVISOR bool default n -config ARCH_NO_SYSDEV_OPS - bool - ---help--- - To be selected by architectures that don't use sysdev class or - sysdev driver power management (suspend/resume) and shutdown - operations. - endmenu diff --git a/drivers/base/base.h b/drivers/base/base.h index 19f49e41ce5d..a34dca0ad041 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -111,8 +111,6 @@ static inline int driver_match_device(struct device_driver *drv, return drv->bus->match ? drv->bus->match(dev, drv) : 1; } -extern void sysdev_shutdown(void); - extern char *make_class_name(const char *name, struct kobject *kobj); extern int devres_release_all(struct device *dev); diff --git a/drivers/base/sys.c b/drivers/base/sys.c index acde9b5ee131..9dff77bfe1e3 100644 --- a/drivers/base/sys.c +++ b/drivers/base/sys.c @@ -328,203 +328,8 @@ void sysdev_unregister(struct sys_device *sysdev) kobject_put(&sysdev->kobj); } - -#ifndef CONFIG_ARCH_NO_SYSDEV_OPS -/** - * sysdev_shutdown - Shut down all system devices. - * - * Loop over each class of system devices, and the devices in each - * of those classes. For each device, we call the shutdown method for - * each driver registered for the device - the auxiliaries, - * and the class driver. - * - * Note: The list is iterated in reverse order, so that we shut down - * child devices before we shut down their parents. The list ordering - * is guaranteed by virtue of the fact that child devices are registered - * after their parents. - */ -void sysdev_shutdown(void) -{ - struct sysdev_class *cls; - - pr_debug("Shutting Down System Devices\n"); - - mutex_lock(&sysdev_drivers_lock); - list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) { - struct sys_device *sysdev; - - pr_debug("Shutting down type '%s':\n", - kobject_name(&cls->kset.kobj)); - - list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { - struct sysdev_driver *drv; - pr_debug(" %s\n", kobject_name(&sysdev->kobj)); - - /* Call auxiliary drivers first */ - list_for_each_entry(drv, &cls->drivers, entry) { - if (drv->shutdown) - drv->shutdown(sysdev); - } - - /* Now call the generic one */ - if (cls->shutdown) - cls->shutdown(sysdev); - } - } - mutex_unlock(&sysdev_drivers_lock); -} - -static void __sysdev_resume(struct sys_device *dev) -{ - struct sysdev_class *cls = dev->cls; - struct sysdev_driver *drv; - - /* First, call the class-specific one */ - if (cls->resume) - cls->resume(dev); - WARN_ONCE(!irqs_disabled(), - "Interrupts enabled after %pF\n", cls->resume); - - /* Call auxiliary drivers next. */ - list_for_each_entry(drv, &cls->drivers, entry) { - if (drv->resume) - drv->resume(dev); - WARN_ONCE(!irqs_disabled(), - "Interrupts enabled after %pF\n", drv->resume); - } -} - -/** - * sysdev_suspend - Suspend all system devices. - * @state: Power state to enter. - * - * We perform an almost identical operation as sysdev_shutdown() - * above, though calling ->suspend() instead. Interrupts are disabled - * when this called. Devices are responsible for both saving state and - * quiescing or powering down the device. - * - * This is only called by the device PM core, so we let them handle - * all synchronization. - */ -int sysdev_suspend(pm_message_t state) -{ - struct sysdev_class *cls; - struct sys_device *sysdev, *err_dev; - struct sysdev_driver *drv, *err_drv; - int ret; - - pr_debug("Checking wake-up interrupts\n"); - - /* Return error code if there are any wake-up interrupts pending */ - ret = check_wakeup_irqs(); - if (ret) - return ret; - - WARN_ONCE(!irqs_disabled(), - "Interrupts enabled while suspending system devices\n"); - - pr_debug("Suspending System Devices\n"); - - list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) { - pr_debug("Suspending type '%s':\n", - kobject_name(&cls->kset.kobj)); - - list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { - pr_debug(" %s\n", kobject_name(&sysdev->kobj)); - - /* Call auxiliary drivers first */ - list_for_each_entry(drv, &cls->drivers, entry) { - if (drv->suspend) { - ret = drv->suspend(sysdev, state); - if (ret) - goto aux_driver; - } - WARN_ONCE(!irqs_disabled(), - "Interrupts enabled after %pF\n", - drv->suspend); - } - - /* Now call the generic one */ - if (cls->suspend) { - ret = cls->suspend(sysdev, state); - if (ret) - goto cls_driver; - WARN_ONCE(!irqs_disabled(), - "Interrupts enabled after %pF\n", - cls->suspend); - } - } - } - return 0; - /* resume current sysdev */ -cls_driver: - drv = NULL; - printk(KERN_ERR "Class suspend failed for %s: %d\n", - kobject_name(&sysdev->kobj), ret); - -aux_driver: - if (drv) - printk(KERN_ERR "Class driver suspend failed for %s: %d\n", - kobject_name(&sysdev->kobj), ret); - list_for_each_entry(err_drv, &cls->drivers, entry) { - if (err_drv == drv) - break; - if (err_drv->resume) - err_drv->resume(sysdev); - } - - /* resume other sysdevs in current class */ - list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { - if (err_dev == sysdev) - break; - pr_debug(" %s\n", kobject_name(&err_dev->kobj)); - __sysdev_resume(err_dev); - } - - /* resume other classes */ - list_for_each_entry_continue(cls, &system_kset->list, kset.kobj.entry) { - list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) { - pr_debug(" %s\n", kobject_name(&err_dev->kobj)); - __sysdev_resume(err_dev); - } - } - return ret; -} -EXPORT_SYMBOL_GPL(sysdev_suspend); - -/** - * sysdev_resume - Bring system devices back to life. - * - * Similar to sysdev_suspend(), but we iterate the list forwards - * to guarantee that parent devices are resumed before their children. - * - * Note: Interrupts are disabled when called. - */ -int sysdev_resume(void) -{ - struct sysdev_class *cls; - - WARN_ONCE(!irqs_disabled(), - "Interrupts enabled while resuming system devices\n"); - - pr_debug("Resuming System Devices\n"); - - list_for_each_entry(cls, &system_kset->list, kset.kobj.entry) { - struct sys_device *sysdev; - - pr_debug("Resuming type '%s':\n", - kobject_name(&cls->kset.kobj)); - - list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { - pr_debug(" %s\n", kobject_name(&sysdev->kobj)); - - __sysdev_resume(sysdev); - } - } - return 0; -} -EXPORT_SYMBOL_GPL(sysdev_resume); -#endif /* CONFIG_ARCH_NO_SYSDEV_OPS */ +EXPORT_SYMBOL_GPL(sysdev_register); +EXPORT_SYMBOL_GPL(sysdev_unregister); int __init system_bus_init(void) { @@ -534,9 +339,6 @@ int __init system_bus_init(void) return 0; } -EXPORT_SYMBOL_GPL(sysdev_register); -EXPORT_SYMBOL_GPL(sysdev_unregister); - #define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr) ssize_t sysdev_store_ulong(struct sys_device *sysdev, diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index a2eee574784e..0b5366b5be20 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -70,12 +70,7 @@ static int xen_suspend(void *data) BUG_ON(!irqs_disabled()); - err = sysdev_suspend(PMSG_FREEZE); - if (!err) { - err = syscore_suspend(); - if (err) - sysdev_resume(); - } + err = syscore_suspend(); if (err) { printk(KERN_ERR "xen_suspend: system core suspend failed: %d\n", err); @@ -102,7 +97,6 @@ static int xen_suspend(void *data) } syscore_resume(); - sysdev_resume(); return 0; } diff --git a/include/linux/device.h b/include/linux/device.h index ab8dfc095709..ea9db9b0f248 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -633,13 +633,6 @@ static inline int devtmpfs_mount(const char *mountpoint) { return 0; } /* drivers/base/power/shutdown.c */ extern void device_shutdown(void); -#ifndef CONFIG_ARCH_NO_SYSDEV_OPS -/* drivers/base/sys.c */ -extern void sysdev_shutdown(void); -#else -static inline void sysdev_shutdown(void) { } -#endif - /* debugging and troubleshooting/diagnostic helpers. */ extern const char *dev_driver_string(const struct device *dev); diff --git a/include/linux/pm.h b/include/linux/pm.h index 512e09177e57..3c053e2beb84 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -529,14 +529,6 @@ struct dev_power_domain { */ #ifdef CONFIG_PM_SLEEP -#ifndef CONFIG_ARCH_NO_SYSDEV_OPS -extern int sysdev_suspend(pm_message_t state); -extern int sysdev_resume(void); -#else -static inline int sysdev_suspend(pm_message_t state) { return 0; } -static inline int sysdev_resume(void) { return 0; } -#endif - extern void device_pm_lock(void); extern void dpm_resume_noirq(pm_message_t state); extern void dpm_resume_end(pm_message_t state); diff --git a/include/linux/sysdev.h b/include/linux/sysdev.h index dfb078db8ebb..d35e783a598c 100644 --- a/include/linux/sysdev.h +++ b/include/linux/sysdev.h @@ -34,12 +34,6 @@ struct sysdev_class { struct list_head drivers; struct sysdev_class_attribute **attrs; struct kset kset; -#ifndef CONFIG_ARCH_NO_SYSDEV_OPS - /* Default operations for these types of devices */ - int (*shutdown)(struct sys_device *); - int (*suspend)(struct sys_device *, pm_message_t state); - int (*resume)(struct sys_device *); -#endif }; struct sysdev_class_attribute { @@ -77,11 +71,6 @@ struct sysdev_driver { struct list_head entry; int (*add)(struct sys_device *); int (*remove)(struct sys_device *); -#ifndef CONFIG_ARCH_NO_SYSDEV_OPS - int (*shutdown)(struct sys_device *); - int (*suspend)(struct sys_device *, pm_message_t state); - int (*resume)(struct sys_device *); -#endif }; diff --git a/kernel/kexec.c b/kernel/kexec.c index 87b77de03dd3..8d814cbc8109 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1531,13 +1531,7 @@ int kernel_kexec(void) if (error) goto Enable_cpus; local_irq_disable(); - /* Suspend system devices */ - error = sysdev_suspend(PMSG_FREEZE); - if (!error) { - error = syscore_suspend(); - if (error) - sysdev_resume(); - } + error = syscore_suspend(); if (error) goto Enable_irqs; } else @@ -1553,7 +1547,6 @@ int kernel_kexec(void) #ifdef CONFIG_KEXEC_JUMP if (kexec_image->preserve_context) { syscore_resume(); - sysdev_resume(); Enable_irqs: local_irq_enable(); Enable_cpus: diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 50aae660174d..554d3b049f35 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -272,12 +272,7 @@ static int create_image(int platform_mode) local_irq_disable(); - error = sysdev_suspend(PMSG_FREEZE); - if (!error) { - error = syscore_suspend(); - if (error) - sysdev_resume(); - } + error = syscore_suspend(); if (error) { printk(KERN_ERR "PM: Some system devices failed to power down, " "aborting hibernation\n"); @@ -302,7 +297,6 @@ static int create_image(int platform_mode) Power_up: syscore_resume(); - sysdev_resume(); /* NOTE: dpm_resume_noirq() is just a resume() for devices * that suspended with irqs off ... no overall powerup. */ @@ -409,12 +403,7 @@ static int resume_target_kernel(bool platform_mode) local_irq_disable(); - error = sysdev_suspend(PMSG_QUIESCE); - if (!error) { - error = syscore_suspend(); - if (error) - sysdev_resume(); - } + error = syscore_suspend(); if (error) goto Enable_irqs; @@ -442,7 +431,6 @@ static int resume_target_kernel(bool platform_mode) touch_softlockup_watchdog(); syscore_resume(); - sysdev_resume(); Enable_irqs: local_irq_enable(); @@ -528,7 +516,6 @@ int hibernation_platform_enter(void) goto Platform_finish; local_irq_disable(); - sysdev_suspend(PMSG_HIBERNATE); syscore_suspend(); if (pm_wakeup_pending()) { error = -EAGAIN; @@ -541,7 +528,6 @@ int hibernation_platform_enter(void) Power_up: syscore_resume(); - sysdev_resume(); local_irq_enable(); enable_nonboot_cpus(); diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 8935369d503a..732d77a957e7 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -163,19 +163,13 @@ static int suspend_enter(suspend_state_t state) arch_suspend_disable_irqs(); BUG_ON(!irqs_disabled()); - error = sysdev_suspend(PMSG_SUSPEND); - if (!error) { - error = syscore_suspend(); - if (error) - sysdev_resume(); - } + error = syscore_suspend(); if (!error) { if (!(suspend_test(TEST_CORE) || pm_wakeup_pending())) { error = suspend_ops->enter(state); events_check_enabled = false; } syscore_resume(); - sysdev_resume(); } arch_suspend_enable_irqs(); diff --git a/kernel/sys.c b/kernel/sys.c index af468edf096a..f0c10385f30c 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -315,7 +315,6 @@ void kernel_restart_prepare(char *cmd) blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); system_state = SYSTEM_RESTART; device_shutdown(); - sysdev_shutdown(); syscore_shutdown(); } @@ -354,7 +353,6 @@ static void kernel_shutdown_prepare(enum system_states state) void kernel_halt(void) { kernel_shutdown_prepare(SYSTEM_HALT); - sysdev_shutdown(); syscore_shutdown(); printk(KERN_EMERG "System halted.\n"); kmsg_dump(KMSG_DUMP_HALT); @@ -374,7 +372,6 @@ void kernel_power_off(void) if (pm_power_off_prepare) pm_power_off_prepare(); disable_nonboot_cpus(); - sysdev_shutdown(); syscore_shutdown(); printk(KERN_EMERG "Power down.\n"); kmsg_dump(KMSG_DUMP_POWEROFF); -- cgit v1.2.3 From ddeb648708108091a641adad0a438ec4fd8bf190 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 15 May 2011 11:38:48 +0200 Subject: PM / Hibernate: Add sysfs knob to control size of memory for drivers Martin reports that on his system hibernation occasionally fails due to the lack of memory, because the radeon driver apparently allocates too much of it during the device freeze stage. It turns out that the amount of memory allocated by radeon during hibernation (and presumably during system suspend too) depends on the utilization of the GPU (e.g. hibernating while there are two KDE 4 sessions with compositing enabled causes radeon to allocate more memory than for one KDE 4 session). In principle it should be possible to use image_size to make the memory preallocation mechanism free enough memory for the radeon driver, but in practice it is not easy to guess the right value because of the way the preallocation code uses image_size. For this reason, it seems reasonable to allow users to control the amount of memory reserved for driver allocations made after the hibernate preallocation, which currently is constant and amounts to 1 MB. Introduce a new sysfs file, /sys/power/reserved_size, whose value will be used as the amount of memory to reserve for the post-preallocation reservations made by device drivers, in bytes. For backwards compatibility, set its default (and initial) value to the currently used number (1 MB). References: https://bugzilla.kernel.org/show_bug.cgi?id=34102 Reported-and-tested-by: Martin Steigerwald Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-power | 14 ++++++++++++++ kernel/power/hibernate.c | 23 +++++++++++++++++++++++ kernel/power/main.c | 1 + kernel/power/power.h | 4 ++++ kernel/power/snapshot.c | 25 ++++++++++++++++++++----- 5 files changed, 62 insertions(+), 5 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 194ca446ac28..b464d12761ba 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -158,3 +158,17 @@ Description: successful, will make the kernel abort a subsequent transition to a sleep state if any wakeup events are reported after the write has returned. + +What: /sys/power/reserved_size +Date: May 2011 +Contact: Rafael J. Wysocki +Description: + The /sys/power/reserved_size file allows user space to control + the amount of memory reserved for allocations made by device + drivers during the "device freeze" stage of hibernation. It can + be written a string representing a non-negative integer that + will be used as the amount of memory to reserve for allocations + made by device drivers' "freeze" callbacks, in bytes. + + Reading from this file will display the current value, which is + set to 1 MB by default. diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 50aae660174d..431721313b71 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -982,10 +982,33 @@ static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *att power_attr(image_size); +static ssize_t reserved_size_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%lu\n", reserved_size); +} + +static ssize_t reserved_size_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long size; + + if (sscanf(buf, "%lu", &size) == 1) { + reserved_size = size; + return n; + } + + return -EINVAL; +} + +power_attr(reserved_size); + static struct attribute * g[] = { &disk_attr.attr, &resume_attr.attr, &image_size_attr.attr, + &reserved_size_attr.attr, NULL, }; diff --git a/kernel/power/main.c b/kernel/power/main.c index de9aef8742f4..2981af4ce7cb 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -337,6 +337,7 @@ static int __init pm_init(void) if (error) return error; hibernate_image_size_init(); + hibernate_reserved_size_init(); power_kobj = kobject_create_and_add("power", NULL); if (!power_kobj) return -ENOMEM; diff --git a/kernel/power/power.h b/kernel/power/power.h index 03634be55f62..9a00a0a26280 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -15,6 +15,7 @@ struct swsusp_info { #ifdef CONFIG_HIBERNATION /* kernel/power/snapshot.c */ +extern void __init hibernate_reserved_size_init(void); extern void __init hibernate_image_size_init(void); #ifdef CONFIG_ARCH_HIBERNATION_HEADER @@ -55,6 +56,7 @@ extern int hibernation_platform_enter(void); #else /* !CONFIG_HIBERNATION */ +static inline void hibernate_reserved_size_init(void) {} static inline void hibernate_image_size_init(void) {} #endif /* !CONFIG_HIBERNATION */ @@ -72,6 +74,8 @@ static struct kobj_attribute _name##_attr = { \ /* Preferred image size in bytes (default 500 MB) */ extern unsigned long image_size; +/* Size of memory reserved for drivers (default SPARE_PAGES x PAGE_SIZE) */ +extern unsigned long reserved_size; extern int in_suspend; extern dev_t swsusp_resume_device; extern sector_t swsusp_resume_block; diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index ca0aacc24874..d69e3323a85d 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -40,6 +40,18 @@ static int swsusp_page_is_free(struct page *); static void swsusp_set_page_forbidden(struct page *); static void swsusp_unset_page_forbidden(struct page *); +/* + * Number of bytes to reserve for memory allocations made by device drivers + * from their ->freeze() and ->freeze_noirq() callbacks so that they don't + * cause image creation to fail (tunable via /sys/power/reserved_size). + */ +unsigned long reserved_size; + +void __init hibernate_reserved_size_init(void) +{ + reserved_size = SPARE_PAGES * PAGE_SIZE; +} + /* * Preferred image size in bytes (tunable via /sys/power/image_size). * When it is set to N, the image creating code will do its best to @@ -1263,11 +1275,13 @@ static unsigned long minimum_image_size(unsigned long saveable) * frame in use. We also need a number of page frames to be free during * hibernation for allocations made while saving the image and for device * drivers, in case they need to allocate memory from their hibernation - * callbacks (these two numbers are given by PAGES_FOR_IO and SPARE_PAGES, - * respectively, both of which are rough estimates). To make this happen, we - * compute the total number of available page frames and allocate at least + * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough + * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through + * /sys/power/reserved_size, respectively). To make this happen, we compute the + * total number of available page frames and allocate at least * - * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + 2 * SPARE_PAGES + * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE) * * of them, which corresponds to the maximum size of a hibernation image. * @@ -1322,7 +1336,8 @@ int hibernate_preallocate_memory(void) count -= totalreserve_pages; /* Compute the maximum number of saveable pages to leave in memory. */ - max_size = (count - (size + PAGES_FOR_IO)) / 2 - 2 * SPARE_PAGES; + max_size = (count - (size + PAGES_FOR_IO)) / 2 + - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE); /* Compute the desired number of image pages specified by image_size. */ size = DIV_ROUND_UP(image_size, PAGE_SIZE); if (size > max_size) -- cgit v1.2.3 From 91e7c75ba93c48a82670d630b9daac92ff70095d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 17 May 2011 23:26:00 +0200 Subject: PM: Allow drivers to allocate memory from .prepare() callbacks safely If device drivers allocate substantial amounts of memory (above 1 MB) in their hibernate .freeze() callbacks (or in their legacy suspend callbcks during hibernation), the subsequent creation of hibernate image may fail due to the lack of memory. This is the case, because the drivers' .freeze() callbacks are executed after the hibernate memory preallocation has been carried out and the preallocated amount of memory may be too small to cover the new driver allocations. Unfortunately, the drivers' .prepare() callbacks also are executed after the hibernate memory preallocation has completed, so they are not suitable for allocating additional memory either. Thus the only way a driver can safely allocate memory during hibernation is to use a hibernate/suspend notifier. However, the notifiers are called before the freezing of user space and the drivers wanting to use them for allocating additional memory may not know how much memory needs to be allocated at that point. To let device drivers overcome this difficulty rework the hibernation sequence so that the memory preallocation is carried out after the drivers' .prepare() callbacks have been executed, so that the .prepare() callbacks can be used for allocating additional memory to be used by the drivers' .freeze() callbacks. Update documentation to match the new behavior of the code. Signed-off-by: Rafael J. Wysocki --- Documentation/power/devices.txt | 14 +++++++---- Documentation/power/notifiers.txt | 51 ++++++++++++++++++--------------------- drivers/base/power/main.c | 18 +++++++++----- include/linux/pm.h | 4 +++ kernel/power/hibernate.c | 17 ++++++++++--- 5 files changed, 61 insertions(+), 43 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 1971bcf48a60..88880839ece4 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -279,11 +279,15 @@ When the system goes into the standby or memory sleep state, the phases are: time.) Unlike the other suspend-related phases, during the prepare phase the device tree is traversed top-down. - The prepare phase uses only a bus callback. After the callback method - returns, no new children may be registered below the device. The method - may also prepare the device or driver in some way for the upcoming - system power transition, but it should not put the device into a - low-power state. + In addition to that, if device drivers need to allocate additional + memory to be able to hadle device suspend correctly, that should be + done in the prepare phase. + + After the prepare callback method returns, no new children may be + registered below the device. The method may also prepare the device or + driver in some way for the upcoming system power transition (for + example, by allocating additional memory required for this purpose), but + it should not put the device into a low-power state. 2. The suspend methods should quiesce the device to stop it from performing I/O. They also may save the device registers and put it into the diff --git a/Documentation/power/notifiers.txt b/Documentation/power/notifiers.txt index cf980709122a..c2a4a346c0d9 100644 --- a/Documentation/power/notifiers.txt +++ b/Documentation/power/notifiers.txt @@ -1,46 +1,41 @@ Suspend notifiers - (C) 2007 Rafael J. Wysocki , GPL - -There are some operations that device drivers may want to carry out in their -.suspend() routines, but shouldn't, because they can cause the hibernation or -suspend to fail. For example, a driver may want to allocate a substantial amount -of memory (like 50 MB) in .suspend(), but that shouldn't be done after the -swsusp's memory shrinker has run. - -Also, there may be some operations, that subsystems want to carry out before a -hibernation/suspend or after a restore/resume, requiring the system to be fully -functional, so the drivers' .suspend() and .resume() routines are not suitable -for this purpose. For example, device drivers may want to upload firmware to -their devices after a restore from a hibernation image, but they cannot do it by -calling request_firmware() from their .resume() routines (user land processes -are frozen at this point). The solution may be to load the firmware into -memory before processes are frozen and upload it from there in the .resume() -routine. Of course, a hibernation notifier may be used for this purpose. - -The subsystems that have such needs can register suspend notifiers that will be -called upon the following events by the suspend core: + (C) 2007-2011 Rafael J. Wysocki , GPL + +There are some operations that subsystems or drivers may want to carry out +before hibernation/suspend or after restore/resume, but they require the system +to be fully functional, so the drivers' and subsystems' .suspend() and .resume() +or even .prepare() and .complete() callbacks are not suitable for this purpose. +For example, device drivers may want to upload firmware to their devices after +resume/restore, but they cannot do it by calling request_firmware() from their +.resume() or .complete() routines (user land processes are frozen at these +points). The solution may be to load the firmware into memory before processes +are frozen and upload it from there in the .resume() routine. +A suspend/hibernation notifier may be used for this purpose. + +The subsystems or drivers having such needs can register suspend notifiers that +will be called upon the following events by the PM core: PM_HIBERNATION_PREPARE The system is going to hibernate or suspend, tasks will be frozen immediately. PM_POST_HIBERNATION The system memory state has been restored from a - hibernation image or an error occurred during the - hibernation. Device drivers' .resume() callbacks have + hibernation image or an error occurred during + hibernation. Device drivers' restore callbacks have been executed and tasks have been thawed. PM_RESTORE_PREPARE The system is going to restore a hibernation image. - If all goes well the restored kernel will issue a + If all goes well, the restored kernel will issue a PM_POST_HIBERNATION notification. -PM_POST_RESTORE An error occurred during the hibernation restore. - Device drivers' .resume() callbacks have been executed +PM_POST_RESTORE An error occurred during restore from hibernation. + Device drivers' restore callbacks have been executed and tasks have been thawed. -PM_SUSPEND_PREPARE The system is preparing for a suspend. +PM_SUSPEND_PREPARE The system is preparing for suspend. PM_POST_SUSPEND The system has just resumed or an error occurred during - the suspend. Device drivers' .resume() callbacks have - been executed and tasks have been thawed. + suspend. Device drivers' resume callbacks have been + executed and tasks have been thawed. It is generally assumed that whatever the notifiers do for PM_HIBERNATION_PREPARE, should be undone for PM_POST_HIBERNATION. Analogously, diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 3b354560f306..aa6320207745 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -579,11 +579,13 @@ static bool is_async(struct device *dev) * Execute the appropriate "resume" callback for all devices whose status * indicates that they are suspended. */ -static void dpm_resume(pm_message_t state) +void dpm_resume(pm_message_t state) { struct device *dev; ktime_t starttime = ktime_get(); + might_sleep(); + mutex_lock(&dpm_list_mtx); pm_transition = state; async_error = 0; @@ -656,10 +658,12 @@ static void device_complete(struct device *dev, pm_message_t state) * Execute the ->complete() callbacks for all devices whose PM status is not * DPM_ON (this allows new devices to be registered). */ -static void dpm_complete(pm_message_t state) +void dpm_complete(pm_message_t state) { struct list_head list; + might_sleep(); + INIT_LIST_HEAD(&list); mutex_lock(&dpm_list_mtx); while (!list_empty(&dpm_prepared_list)) { @@ -688,7 +692,6 @@ static void dpm_complete(pm_message_t state) */ void dpm_resume_end(pm_message_t state) { - might_sleep(); dpm_resume(state); dpm_complete(state); } @@ -912,11 +915,13 @@ static int device_suspend(struct device *dev) * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices. * @state: PM transition of the system being carried out. */ -static int dpm_suspend(pm_message_t state) +int dpm_suspend(pm_message_t state) { ktime_t starttime = ktime_get(); int error = 0; + might_sleep(); + mutex_lock(&dpm_list_mtx); pm_transition = state; async_error = 0; @@ -1003,10 +1008,12 @@ static int device_prepare(struct device *dev, pm_message_t state) * * Execute the ->prepare() callback(s) for all devices. */ -static int dpm_prepare(pm_message_t state) +int dpm_prepare(pm_message_t state) { int error = 0; + might_sleep(); + mutex_lock(&dpm_list_mtx); while (!list_empty(&dpm_list)) { struct device *dev = to_device(dpm_list.next); @@ -1055,7 +1062,6 @@ int dpm_suspend_start(pm_message_t state) { int error; - might_sleep(); error = dpm_prepare(state); if (!error) error = dpm_suspend(state); diff --git a/include/linux/pm.h b/include/linux/pm.h index 3cc3e7e589f0..dce7c7148771 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -533,10 +533,14 @@ struct dev_power_domain { extern void device_pm_lock(void); extern void dpm_resume_noirq(pm_message_t state); extern void dpm_resume_end(pm_message_t state); +extern void dpm_resume(pm_message_t state); +extern void dpm_complete(pm_message_t state); extern void device_pm_unlock(void); extern int dpm_suspend_noirq(pm_message_t state); extern int dpm_suspend_start(pm_message_t state); +extern int dpm_suspend(pm_message_t state); +extern int dpm_prepare(pm_message_t state); extern void __suspend_report_result(const char *function, void *fn, int ret); diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 95a2ac40f48c..f9bec56d8825 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -327,20 +327,25 @@ static int create_image(int platform_mode) int hibernation_snapshot(int platform_mode) { + pm_message_t msg = PMSG_RECOVER; int error; error = platform_begin(platform_mode); if (error) goto Close; + error = dpm_prepare(PMSG_FREEZE); + if (error) + goto Complete_devices; + /* Preallocate image memory before shutting down devices. */ error = hibernate_preallocate_memory(); if (error) - goto Close; + goto Complete_devices; suspend_console(); pm_restrict_gfp_mask(); - error = dpm_suspend_start(PMSG_FREEZE); + error = dpm_suspend(PMSG_FREEZE); if (error) goto Recover_platform; @@ -358,13 +363,17 @@ int hibernation_snapshot(int platform_mode) if (error || !in_suspend) swsusp_free(); - dpm_resume_end(in_suspend ? - (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); + msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE; + dpm_resume(msg); if (error || !in_suspend) pm_restore_gfp_mask(); resume_console(); + + Complete_devices: + dpm_complete(msg); + Close: platform_end(platform_mode); return error; -- cgit v1.2.3 From 4e2d9491a78929badcf774869b458486acb96365 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 24 May 2011 00:21:26 +0200 Subject: PM / Hibernate: Update some comments in core hibernate code Some comments in the core hibernate code are outdated, some aren't necessary any more and at least one of them is plain wrong. Remove those comments or update them. Signed-off-by: Rafael J. Wysocki --- kernel/power/hibernate.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index f9bec56d8825..6418d8c8cdb2 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -248,12 +248,6 @@ static int create_image(int platform_mode) if (error) return error; - /* At this point, dpm_suspend_start() has been called, but *not* - * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now. - * Otherwise, drivers for some devices (e.g. interrupt controllers) - * become desynchronized with the actual state of the hardware - * at resume time, and evil weirdness ensues. - */ error = dpm_suspend_noirq(PMSG_FREEZE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " @@ -297,9 +291,6 @@ static int create_image(int platform_mode) Power_up: syscore_resume(); - /* NOTE: dpm_resume_noirq() is just a resume() for devices - * that suspended with irqs off ... no overall powerup. - */ Enable_irqs: local_irq_enable(); @@ -416,24 +407,26 @@ static int resume_target_kernel(bool platform_mode) if (error) goto Enable_irqs; - /* We'll ignore saved state, but this gets preempt count (etc) right */ save_processor_state(); error = restore_highmem(); if (!error) { error = swsusp_arch_resume(); /* * The code below is only ever reached in case of a failure. - * Otherwise execution continues at place where - * swsusp_arch_suspend() was called + * Otherwise, execution continues at the place where + * swsusp_arch_suspend() was called. */ BUG_ON(!error); - /* This call to restore_highmem() undos the previous one */ + /* + * This call to restore_highmem() reverts the changes made by + * the previous one. + */ restore_highmem(); } /* * The only reason why swsusp_arch_resume() can fail is memory being * very tight, so we have to free it as soon as we can to avoid - * subsequent failures + * subsequent failures. */ swsusp_free(); restore_processor_state(); -- cgit v1.2.3 From 354258011e8e86961f7a72ad154ca8caf0c4c6f7 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 24 May 2011 23:35:55 +0200 Subject: PM / Hibernate: Remove arch_prepare_suspend() All architectures supporting hibernation define arch_prepare_suspend() as an empty function, so remove it. Signed-off-by: Rafael J. Wysocki --- arch/frv/include/asm/suspend.h | 20 -------------------- arch/mips/include/asm/suspend.h | 2 -- arch/powerpc/include/asm/suspend.h | 6 ------ arch/powerpc/kernel/swsusp.c | 1 - arch/s390/include/asm/suspend.h | 10 ---------- arch/sh/include/asm/suspend.h | 1 - arch/unicore32/include/asm/suspend.h | 1 - arch/x86/include/asm/suspend_32.h | 2 -- arch/x86/include/asm/suspend_64.h | 5 ----- kernel/power/hibernate.c | 5 ----- 10 files changed, 53 deletions(-) delete mode 100644 arch/frv/include/asm/suspend.h delete mode 100644 arch/powerpc/include/asm/suspend.h delete mode 100644 arch/s390/include/asm/suspend.h (limited to 'kernel/power/hibernate.c') diff --git a/arch/frv/include/asm/suspend.h b/arch/frv/include/asm/suspend.h deleted file mode 100644 index 5fa7b5a6ee40..000000000000 --- a/arch/frv/include/asm/suspend.h +++ /dev/null @@ -1,20 +0,0 @@ -/* suspend.h: suspension stuff - * - * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#ifndef _ASM_SUSPEND_H -#define _ASM_SUSPEND_H - -static inline int arch_prepare_suspend(void) -{ - return 0; -} - -#endif /* _ASM_SUSPEND_H */ diff --git a/arch/mips/include/asm/suspend.h b/arch/mips/include/asm/suspend.h index 294cdb66c5fc..3adac3b53d19 100644 --- a/arch/mips/include/asm/suspend.h +++ b/arch/mips/include/asm/suspend.h @@ -1,8 +1,6 @@ #ifndef __ASM_SUSPEND_H #define __ASM_SUSPEND_H -static inline int arch_prepare_suspend(void) { return 0; } - /* References to section boundaries */ extern const void __nosave_begin, __nosave_end; diff --git a/arch/powerpc/include/asm/suspend.h b/arch/powerpc/include/asm/suspend.h deleted file mode 100644 index c6efc3466aa6..000000000000 --- a/arch/powerpc/include/asm/suspend.h +++ /dev/null @@ -1,6 +0,0 @@ -#ifndef __ASM_POWERPC_SUSPEND_H -#define __ASM_POWERPC_SUSPEND_H - -static inline int arch_prepare_suspend(void) { return 0; } - -#endif /* __ASM_POWERPC_SUSPEND_H */ diff --git a/arch/powerpc/kernel/swsusp.c b/arch/powerpc/kernel/swsusp.c index 560c96119501..aa17b76dd427 100644 --- a/arch/powerpc/kernel/swsusp.c +++ b/arch/powerpc/kernel/swsusp.c @@ -10,7 +10,6 @@ */ #include -#include #include #include #include diff --git a/arch/s390/include/asm/suspend.h b/arch/s390/include/asm/suspend.h deleted file mode 100644 index dc75c616eafe..000000000000 --- a/arch/s390/include/asm/suspend.h +++ /dev/null @@ -1,10 +0,0 @@ -#ifndef __ASM_S390_SUSPEND_H -#define __ASM_S390_SUSPEND_H - -static inline int arch_prepare_suspend(void) -{ - return 0; -} - -#endif - diff --git a/arch/sh/include/asm/suspend.h b/arch/sh/include/asm/suspend.h index 64eb41a063e8..e14567a7e9a1 100644 --- a/arch/sh/include/asm/suspend.h +++ b/arch/sh/include/asm/suspend.h @@ -3,7 +3,6 @@ #ifndef __ASSEMBLY__ #include -static inline int arch_prepare_suspend(void) { return 0; } #include diff --git a/arch/unicore32/include/asm/suspend.h b/arch/unicore32/include/asm/suspend.h index 88a9c0f32b21..65bad75c7e96 100644 --- a/arch/unicore32/include/asm/suspend.h +++ b/arch/unicore32/include/asm/suspend.h @@ -14,7 +14,6 @@ #define __UNICORE_SUSPEND_H__ #ifndef __ASSEMBLY__ -static inline int arch_prepare_suspend(void) { return 0; } #include diff --git a/arch/x86/include/asm/suspend_32.h b/arch/x86/include/asm/suspend_32.h index fd921c3a6841..487055c8c1aa 100644 --- a/arch/x86/include/asm/suspend_32.h +++ b/arch/x86/include/asm/suspend_32.h @@ -9,8 +9,6 @@ #include #include -static inline int arch_prepare_suspend(void) { return 0; } - /* image of the saved processor state */ struct saved_context { u16 es, fs, gs, ss; diff --git a/arch/x86/include/asm/suspend_64.h b/arch/x86/include/asm/suspend_64.h index 8d942afae681..09b0bf104156 100644 --- a/arch/x86/include/asm/suspend_64.h +++ b/arch/x86/include/asm/suspend_64.h @@ -9,11 +9,6 @@ #include #include -static inline int arch_prepare_suspend(void) -{ - return 0; -} - /* * Image of the saved processor state, used by the low level ACPI suspend to * RAM code and by the low level hibernation code. diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 6418d8c8cdb2..16aa3bcd6b54 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -25,7 +25,6 @@ #include #include #include -#include #include "power.h" @@ -244,10 +243,6 @@ static int create_image(int platform_mode) { int error; - error = arch_prepare_suspend(); - if (error) - return error; - error = dpm_suspend_noirq(PMSG_FREEZE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " -- cgit v1.2.3 From f42a9813fbf930fea3bdd0524dcb43c7feb0c977 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 24 May 2011 23:36:06 +0200 Subject: PM / Hibernate: Update kerneldoc comments in hibernate.c Some of the kerneldoc comments in kernel/power/hibernate.c are outdated and some of them don't adhere to the kernel's standards. Update them and make them look in a consistent way. Signed-off-by: Rafael J. Wysocki Acked-by: Randy Dunlap --- kernel/power/hibernate.c | 194 +++++++++++++++++++++++++---------------------- 1 file changed, 104 insertions(+), 90 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 16aa3bcd6b54..8f7b1db1ece1 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -54,10 +54,9 @@ static int hibernation_mode = HIBERNATION_SHUTDOWN; static const struct platform_hibernation_ops *hibernation_ops; /** - * hibernation_set_ops - set the global hibernate operations - * @ops: the hibernation operations to use in subsequent hibernation transitions + * hibernation_set_ops - Set the global hibernate operations. + * @ops: Hibernation operations to use in subsequent hibernation transitions. */ - void hibernation_set_ops(const struct platform_hibernation_ops *ops) { if (ops && !(ops->begin && ops->end && ops->pre_snapshot @@ -114,10 +113,9 @@ static int hibernation_test(int level) { return 0; } #endif /* !CONFIG_PM_DEBUG */ /** - * platform_begin - tell the platform driver that we're starting - * hibernation + * platform_begin - Call platform to start hibernation. + * @platform_mode: Whether or not to use the platform driver. */ - static int platform_begin(int platform_mode) { return (platform_mode && hibernation_ops) ? @@ -125,10 +123,9 @@ static int platform_begin(int platform_mode) } /** - * platform_end - tell the platform driver that we've entered the - * working state + * platform_end - Call platform to finish transition to the working state. + * @platform_mode: Whether or not to use the platform driver. */ - static void platform_end(int platform_mode) { if (platform_mode && hibernation_ops) @@ -136,8 +133,11 @@ static void platform_end(int platform_mode) } /** - * platform_pre_snapshot - prepare the machine for hibernation using the - * platform driver if so configured and return an error code if it fails + * platform_pre_snapshot - Call platform to prepare the machine for hibernation. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver to prepare the system for creating a hibernate image, + * if so configured, and return an error code if that fails. */ static int platform_pre_snapshot(int platform_mode) @@ -147,10 +147,14 @@ static int platform_pre_snapshot(int platform_mode) } /** - * platform_leave - prepare the machine for switching to the normal mode - * of operation using the platform driver (called with interrupts disabled) + * platform_leave - Call platform to prepare a transition to the working state. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver prepare to prepare the machine for switching to the + * normal mode of operation. + * + * This routine is called on one CPU with interrupts disabled. */ - static void platform_leave(int platform_mode) { if (platform_mode && hibernation_ops) @@ -158,10 +162,14 @@ static void platform_leave(int platform_mode) } /** - * platform_finish - switch the machine to the normal mode of operation - * using the platform driver (must be called after platform_prepare()) + * platform_finish - Call platform to switch the system to the working state. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver to switch the machine to the normal mode of + * operation. + * + * This routine must be called after platform_prepare(). */ - static void platform_finish(int platform_mode) { if (platform_mode && hibernation_ops) @@ -169,11 +177,15 @@ static void platform_finish(int platform_mode) } /** - * platform_pre_restore - prepare the platform for the restoration from a - * hibernation image. If the restore fails after this function has been - * called, platform_restore_cleanup() must be called. + * platform_pre_restore - Prepare for hibernate image restoration. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver to prepare the system for resume from a hibernation + * image. + * + * If the restore fails after this function has been called, + * platform_restore_cleanup() must be called. */ - static int platform_pre_restore(int platform_mode) { return (platform_mode && hibernation_ops) ? @@ -181,12 +193,16 @@ static int platform_pre_restore(int platform_mode) } /** - * platform_restore_cleanup - switch the platform to the normal mode of - * operation after a failing restore. If platform_pre_restore() has been - * called before the failing restore, this function must be called too, - * regardless of the result of platform_pre_restore(). + * platform_restore_cleanup - Switch to the working state after failing restore. + * @platform_mode: Whether or not to use the platform driver. + * + * Use the platform driver to switch the system to the normal mode of operation + * after a failing restore. + * + * If platform_pre_restore() has been called before the failing restore, this + * function must be called too, regardless of the result of + * platform_pre_restore(). */ - static void platform_restore_cleanup(int platform_mode) { if (platform_mode && hibernation_ops) @@ -194,10 +210,9 @@ static void platform_restore_cleanup(int platform_mode) } /** - * platform_recover - recover the platform from a failure to suspend - * devices. + * platform_recover - Recover from a failure to suspend devices. + * @platform_mode: Whether or not to use the platform driver. */ - static void platform_recover(int platform_mode) { if (platform_mode && hibernation_ops && hibernation_ops->recover) @@ -205,13 +220,12 @@ static void platform_recover(int platform_mode) } /** - * swsusp_show_speed - print the time elapsed between two events. - * @start: Starting event. - * @stop: Final event. - * @nr_pages - number of pages processed between @start and @stop - * @msg - introductory message to print + * swsusp_show_speed - Print time elapsed between two events during hibernation. + * @start: Starting event. + * @stop: Final event. + * @nr_pages: Number of memory pages processed between @start and @stop. + * @msg: Additional diagnostic message to print. */ - void swsusp_show_speed(struct timeval *start, struct timeval *stop, unsigned nr_pages, char *msg) { @@ -234,11 +248,14 @@ void swsusp_show_speed(struct timeval *start, struct timeval *stop, } /** - * create_image - freeze devices that need to be frozen with interrupts - * off, create the hibernation image and thaw those devices. Control - * reappears in this routine after a restore. + * create_image - Create a hibernation image. + * @platform_mode: Whether or not to use the platform driver. + * + * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image + * and execute the drivers' .thaw_noirq() callbacks. + * + * Control reappears in this routine after the subsequent restore. */ - static int create_image(int platform_mode) { int error; @@ -303,14 +320,11 @@ static int create_image(int platform_mode) } /** - * hibernation_snapshot - quiesce devices and create the hibernation - * snapshot image. - * @platform_mode - if set, use the platform driver, if available, to - * prepare the platform firmware for the power transition. + * hibernation_snapshot - Quiesce devices and create a hibernation image. + * @platform_mode: If set, use platform driver to prepare for the transition. * - * Must be called with pm_mutex held + * This routine must be called with pm_mutex held. */ - int hibernation_snapshot(int platform_mode) { pm_message_t msg = PMSG_RECOVER; @@ -370,13 +384,14 @@ int hibernation_snapshot(int platform_mode) } /** - * resume_target_kernel - prepare devices that need to be suspended with - * interrupts off, restore the contents of highmem that have not been - * restored yet from the image and run the low level code that will restore - * the remaining contents of memory and switch to the just restored target - * kernel. + * resume_target_kernel - Restore system state from a hibernation image. + * @platform_mode: Whether or not to use the platform driver. + * + * Execute device drivers' .freeze_noirq() callbacks, restore the contents of + * highmem that have not been restored yet from the image and run the low-level + * code that will restore the remaining contents of memory and switch to the + * just restored target kernel. */ - static int resume_target_kernel(bool platform_mode) { int error; @@ -444,14 +459,12 @@ static int resume_target_kernel(bool platform_mode) } /** - * hibernation_restore - quiesce devices and restore the hibernation - * snapshot image. If successful, control returns in hibernation_snaphot() - * @platform_mode - if set, use the platform driver, if available, to - * prepare the platform firmware for the transition. + * hibernation_restore - Quiesce devices and restore from a hibernation image. + * @platform_mode: If set, use platform driver to prepare for the transition. * - * Must be called with pm_mutex held + * This routine must be called with pm_mutex held. If it is successful, control + * reappears in the restored target kernel in hibernation_snaphot(). */ - int hibernation_restore(int platform_mode) { int error; @@ -471,10 +484,8 @@ int hibernation_restore(int platform_mode) } /** - * hibernation_platform_enter - enter the hibernation state using the - * platform driver (if available) + * hibernation_platform_enter - Power off the system using the platform driver. */ - int hibernation_platform_enter(void) { int error; @@ -545,12 +556,12 @@ int hibernation_platform_enter(void) } /** - * power_down - Shut the machine down for hibernation. + * power_down - Shut the machine down for hibernation. * - * Use the platform driver, if configured so; otherwise try - * to power off or reboot. + * Use the platform driver, if configured, to put the system into the sleep + * state corresponding to hibernation, or try to power it off or reboot, + * depending on the value of hibernation_mode. */ - static void power_down(void) { switch (hibernation_mode) { @@ -587,9 +598,8 @@ static int prepare_processes(void) } /** - * hibernate - The granpappy of the built-in hibernation management + * hibernate - Carry out system hibernation, including saving the image. */ - int hibernate(void) { int error; @@ -667,17 +677,20 @@ int hibernate(void) /** - * software_resume - Resume from a saved image. + * software_resume - Resume from a saved hibernation image. + * + * This routine is called as a late initcall, when all devices have been + * discovered and initialized already. * - * Called as a late_initcall (so all devices are discovered and - * initialized), we call swsusp to see if we have a saved image or not. - * If so, we quiesce devices, the restore the saved image. We will - * return above (in hibernate() ) if everything goes well. - * Otherwise, we fail gracefully and return to the normally - * scheduled program. + * The image reading code is called to see if there is a hibernation image + * available for reading. If that is the case, devices are quiesced and the + * contents of memory is restored from the saved image. * + * If this is successful, control reappears in the restored target kernel in + * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine + * attempts to recover gracefully and make the kernel return to the normal mode + * of operation. */ - static int software_resume(void) { int error; @@ -807,21 +820,17 @@ static const char * const hibernation_modes[] = { [HIBERNATION_TESTPROC] = "testproc", }; -/** - * disk - Control hibernation mode - * - * Suspend-to-disk can be handled in several ways. We have a few options - * for putting the system to sleep - using the platform driver (e.g. ACPI - * or other hibernation_ops), powering off the system or rebooting the - * system (for testing) as well as the two test modes. +/* + * /sys/power/disk - Control hibernation mode. * - * The system can support 'platform', and that is known a priori (and - * encoded by the presence of hibernation_ops). However, the user may - * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the - * test modes, 'test' or 'testproc'. + * Hibernation can be handled in several ways. There are a few different ways + * to put the system into the sleep state: using the platform driver (e.g. ACPI + * or other hibernation_ops), powering it off or rebooting it (for testing + * mostly), or using one of the two available test modes. * - * show() will display what the mode is currently set to. - * store() will accept one of + * The sysfs file /sys/power/disk provides an interface for selecting the + * hibernation mode to use. Reading from this file causes the available modes + * to be printed. There are 5 modes that can be supported: * * 'platform' * 'shutdown' @@ -829,8 +838,14 @@ static const char * const hibernation_modes[] = { * 'test' * 'testproc' * - * It will only change to 'platform' if the system - * supports it (as determined by having hibernation_ops). + * If a platform hibernation driver is in use, 'platform' will be supported + * and will be used by default. Otherwise, 'shutdown' will be used by default. + * The selected option (i.e. the one corresponding to the current value of + * hibernation_mode) is enclosed by a square bracket. + * + * To select a given hibernation mode it is necessary to write the mode's + * string representation (as returned by reading from /sys/power/disk) back + * into /sys/power/disk. */ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, @@ -863,7 +878,6 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, return buf-start; } - static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t n) { -- cgit v1.2.3