Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751678Ab1CJLas (ORCPT ); Thu, 10 Mar 2011 06:30:48 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:45574 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751069Ab1CJLaq (ORCPT ); Thu, 10 Mar 2011 06:30:46 -0500 From: "Rafael J. Wysocki" To: Alan Stern Subject: [RFC][Update][PATCH 1/2] Introduce struct syscore_ops and related functionality Date: Thu, 10 Mar 2011 12:30:45 +0100 User-Agent: KMail/1.13.5 (Linux/2.6.38-rc8+; KDE/4.4.4; x86_64; ; ) Cc: LKML , Greg KH , Jesse Barnes , mingo@redhat.com, "H. Peter Anvin" , Kay Sievers , Linux PM mailing list , tglx@linutronix.de References: In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201103101230.45569.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10800 Lines: 371 On Thursday, March 10, 2011, Alan Stern wrote: > On Thu, 10 Mar 2011, Rafael J. Wysocki wrote: > > > Some subsystems need to carry out suspend/resume and shutdown > > operations with one CPU on-line and interrupts disabled. The only > > way to register such operations is to define a sysdev class and > > a sysdev specifically for this purpose which is cumbersome and > > inefficient. Moreover, the arguments taken by sysdev suspend, > > resume and shutdown callbacks are practically never necessary. > > > > For this reason, introduce a simpler interface allowing subsystems > > to register operations to be executed very late during system suspend > > and shutdown and very early during resume in the form of > > strcut syscore_ops objects. > > ... > > > Index: linux-2.6/drivers/base/syscore.c > > =================================================================== > > --- /dev/null > > +++ linux-2.6/drivers/base/syscore.c > > It's true that the existing sys.c file lies in drivers/base; this is > presumably because it handles a bunch of class-related registration > stuff. Now you're getting rid of all that, leaving just the > power-related operations, so doesn't it make more sense to put this > file in drivers/base/power? > > > +/** > > + * syscore_suspend - Execute all the registered system core suspend callbacks. > > + * > > + * This function is executed with one CPU on-line and disabled interrupts. > > + */ > > +int syscore_suspend(void) > > +{ > > + struct syscore_ops *ops; > > + > > + list_for_each_entry_reverse(ops, &syscore_ops_list, node) > > + if (ops->suspend) { > > + int ret = ops->suspend(); > > + if (ret) { > > + pr_err("PM: System core suspend callback " > > + "%pF failed.\n", ops->suspend); > > + return ret; > > If an error occurs, you need to go back and resume all the things that > were suspended. At least, that's what the code in sysdev_suspend does. > > > + } > > + } > > + > > + return 0; > > +} Below is a new version of the patch. I've taken your comment on the failing suspend into account, fix the list traversal direction in syscore_shutdown() and added some debug statements. Thanks, Rafael --- Some subsystems need to carry out suspend/resume and shutdown operations with one CPU on-line and interrupts disabled. The only way to register such operations is to define a sysdev class and a sysdev specifically for this purpose which is cumbersome and inefficient. Moreover, the arguments taken by sysdev suspend, resume and shutdown callbacks are practically never necessary. For this reason, introduce a simpler interface allowing subsystems to register operations to be executed very late during system suspend and shutdown and very early during resume in the form of strcut syscore_ops objects. --- drivers/base/Makefile | 2 drivers/base/syscore.c | 107 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/syscore_ops.h | 29 +++++++++++ kernel/power/hibernate.c | 9 +++ kernel/power/suspend.c | 4 + kernel/sys.c | 4 + 6 files changed, 154 insertions(+), 1 deletion(-) Index: linux-2.6/include/linux/syscore_ops.h =================================================================== --- /dev/null +++ linux-2.6/include/linux/syscore_ops.h @@ -0,0 +1,29 @@ +/* + * syscore_ops.h - System core operations. + * + * Copyright (C) 2011 Rafael J. Wysocki , Novell Inc. + * + * This file is released under the GPLv2. + */ + +#ifndef _LINUX_SYSCORE_OPS_H +#define _LINUX_SYSCORE_OPS_H + +#include + +struct syscore_ops { + struct list_head node; + int (*suspend)(void); + void (*resume)(void); + void (*shutdown)(void); +}; + +extern void register_syscore_ops(struct syscore_ops *ops); +extern void unregister_syscore_ops(struct syscore_ops *ops); +#ifdef CONFIG_PM_SLEEP +extern int syscore_suspend(void); +extern void syscore_resume(void); +#endif +extern void syscore_shutdown(void); + +#endif Index: linux-2.6/drivers/base/syscore.c =================================================================== --- /dev/null +++ linux-2.6/drivers/base/syscore.c @@ -0,0 +1,107 @@ +/* + * syscore.c - Execution of system core operations. + * + * Copyright (C) 2011 Rafael J. Wysocki , Novell Inc. + * + * This file is released under the GPLv2. + */ + +#include +#include +#include + +static LIST_HEAD(syscore_ops_list); +static DEFINE_MUTEX(syscore_ops_lock); + +/** + * register_syscore_ops - Register a set of system core operations. + * @ops: System core operations to register. + */ +void register_syscore_ops(struct syscore_ops *ops) +{ + mutex_lock(&syscore_ops_lock); + list_add_tail(&ops->node, &syscore_ops_list); + mutex_unlock(&syscore_ops_lock); +} +EXPORT_SYMBOL_GPL(register_syscore_ops); + +/** + * unregister_syscore_ops - Unregister a set of system core operations. + * @ops: System core operations to unregister. + */ +void unregister_syscore_ops(struct syscore_ops *ops) +{ + mutex_lock(&syscore_ops_lock); + list_del(&ops->node); + mutex_unlock(&syscore_ops_lock); +} +EXPORT_SYMBOL_GPL(unregister_syscore_ops); + +#ifdef CONFIG_PM_SLEEP +/** + * syscore_suspend - Execute all the registered system core suspend callbacks. + * + * This function is executed with one CPU on-line and disabled interrupts. + */ +int syscore_suspend(void) +{ + struct syscore_ops *ops; + int ret = 0; + + list_for_each_entry_reverse(ops, &syscore_ops_list, node) + if (ops->suspend) { + if (initcall_debug) + pr_info("PM: Calling %pF\n", ops->suspend); + ret = ops->suspend(); + if (ret) + goto err_out; + } + + return 0; + + err_out: + pr_err("PM: System core suspend callback %pF failed.\n", ops->suspend); + + list_for_each_entry_continue(ops, &syscore_ops_list, node) + if (ops->resume) + ops->resume(); + + return ret; +} + +/** + * syscore_resume - Execute all the registered system core resume callbacks. + * + * This function is executed with one CPU on-line and disabled interrupts. + */ +void syscore_resume(void) +{ + struct syscore_ops *ops; + + list_for_each_entry(ops, &syscore_ops_list, node) + if (ops->resume) { + if (initcall_debug) + pr_info("PM: Calling %pF\n", ops->resume); + ops->resume(); + } +} +#endif /* CONFIG_PM_SLEEP */ + +/** + * syscore_shutdown - Execute all the registered system core shutdown callbacks. + */ +void syscore_shutdown(void) +{ + struct syscore_ops *ops; + + mutex_lock(&syscore_ops_lock); + + list_for_each_entry_reverse(ops, &syscore_ops_list, node) + if (ops->shutdown) { + if (initcall_debug) + pr_info("PM: Calling %pF\n", ops->shutdown); + ops->shutdown(); + } + + mutex_unlock(&syscore_ops_lock); +} Index: linux-2.6/kernel/power/suspend.c =================================================================== --- linux-2.6.orig/kernel/power/suspend.c +++ linux-2.6/kernel/power/suspend.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include "power.h" @@ -163,11 +164,14 @@ static int suspend_enter(suspend_state_t BUG_ON(!irqs_disabled()); error = sysdev_suspend(PMSG_SUSPEND); + if (!error) + 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(); } Index: linux-2.6/kernel/power/hibernate.c =================================================================== --- linux-2.6.orig/kernel/power/hibernate.c +++ linux-2.6/kernel/power/hibernate.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -272,6 +273,8 @@ static int create_image(int platform_mod local_irq_disable(); error = sysdev_suspend(PMSG_FREEZE); + if (!error) + error = syscore_suspend(); if (error) { printk(KERN_ERR "PM: Some system devices failed to power down, " "aborting hibernation\n"); @@ -295,6 +298,7 @@ static int create_image(int platform_mod } Power_up: + syscore_resume(); sysdev_resume(); /* NOTE: dpm_resume_noirq() is just a resume() for devices * that suspended with irqs off ... no overall powerup. @@ -403,6 +407,8 @@ static int resume_target_kernel(bool pla local_irq_disable(); error = sysdev_suspend(PMSG_QUIESCE); + if (!error) + error = syscore_suspend(); if (error) goto Enable_irqs; @@ -429,6 +435,7 @@ static int resume_target_kernel(bool pla restore_processor_state(); touch_softlockup_watchdog(); + syscore_resume(); sysdev_resume(); Enable_irqs: @@ -516,6 +523,7 @@ int hibernation_platform_enter(void) local_irq_disable(); sysdev_suspend(PMSG_HIBERNATE); + syscore_suspend(); if (pm_wakeup_pending()) { error = -EAGAIN; goto Power_up; @@ -526,6 +534,7 @@ int hibernation_platform_enter(void) while (1); Power_up: + syscore_resume(); sysdev_resume(); local_irq_enable(); enable_nonboot_cpus(); Index: linux-2.6/kernel/sys.c =================================================================== --- linux-2.6.orig/kernel/sys.c +++ linux-2.6/kernel/sys.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -298,6 +299,7 @@ void kernel_restart_prepare(char *cmd) system_state = SYSTEM_RESTART; device_shutdown(); sysdev_shutdown(); + syscore_shutdown(); } /** @@ -336,6 +338,7 @@ void kernel_halt(void) { kernel_shutdown_prepare(SYSTEM_HALT); sysdev_shutdown(); + syscore_shutdown(); printk(KERN_EMERG "System halted.\n"); kmsg_dump(KMSG_DUMP_HALT); machine_halt(); @@ -355,6 +358,7 @@ void kernel_power_off(void) pm_power_off_prepare(); disable_nonboot_cpus(); sysdev_shutdown(); + syscore_shutdown(); printk(KERN_EMERG "Power down.\n"); kmsg_dump(KMSG_DUMP_POWEROFF); machine_power_off(); Index: linux-2.6/drivers/base/Makefile =================================================================== --- linux-2.6.orig/drivers/base/Makefile +++ linux-2.6/drivers/base/Makefile @@ -1,6 +1,6 @@ # Makefile for the Linux device tree -obj-y := core.o sys.o bus.o dd.o \ +obj-y := core.o sys.o bus.o dd.o syscore.o \ driver.o class.o platform.o \ cpu.o firmware.o init.o map.o devres.o \ attribute_container.o transport_class.o -- 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/