From 4e2d9491a78929badcf774869b458486acb96365 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 24 May 2011 00:21:26 +0200 Subject: [PATCH 1/4] PM / Hibernate: Update some comments in core hibernate code Some comments in the core hibernate code are outdated, some aren't necessary any more and at least one of them is plain wrong.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(-) 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(); From 354258011e8e86961f7a72ad154ca8caf0c4c6f7 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 24 May 2011 23:35:55 +0200 Subject: [PATCH 2/4] 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 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, " From f42a9813fbf930fea3bdd0524dcb43c7feb0c977 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 24 May 2011 23:36:06 +0200 Subject: [PATCH 3/4] 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(-) 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. * - * 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. + * This routine is called as a late initcall, when all devices have been + * discovered and initialized already. * + * 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 +/* + * /sys/power/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. + * 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. * - * 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'. - * - * 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) { From 0775a60aca2375ea5598741b30d13fe6d3f15617 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 27 May 2011 00:05:23 +0200 Subject: [PATCH 4/4] PM: Fix PM QOS's user mode interface to work with ASCII input Make pm_qos_power_write() accept values passed to it in the ASCII hex format either with or without an ending newline. Signed-off-by: Rafael J. Wysocki Acked-by: Mark Gross --- kernel/pm_qos_params.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index 0da058bff8eb..68df076fec5d 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -40,6 +40,7 @@ #include #include #include +#include #include @@ -404,24 +405,36 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) { s32 value; - int x; - char ascii_value[11]; struct pm_qos_request_list *pm_qos_req; if (count == sizeof(s32)) { if (copy_from_user(&value, buf, sizeof(s32))) return -EFAULT; - } else if (count == 11) { /* len('0x12345678/0') */ - if (copy_from_user(ascii_value, buf, 11)) + } else if (count <= 11) { /* ASCII perhaps? */ + char ascii_value[11]; + unsigned long int ulval; + int ret; + + if (copy_from_user(ascii_value, buf, count)) return -EFAULT; - if (strlen(ascii_value) != 10) + + if (count > 10) { + if (ascii_value[10] == '\n') + ascii_value[10] = '\0'; + else + return -EINVAL; + } else { + ascii_value[count] = '\0'; + } + ret = strict_strtoul(ascii_value, 16, &ulval); + if (ret) { + pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); return -EINVAL; - x = sscanf(ascii_value, "%x", &value); - if (x != 1) - return -EINVAL; - pr_debug("%s, %d, 0x%x\n", ascii_value, x, value); - } else + } + value = (s32)lower_32_bits(ulval); + } else { return -EINVAL; + } pm_qos_req = filp->private_data; pm_qos_update_request(pm_qos_req, value);