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authorRafael J. Wysocki <rjw@sisk.pl>2009-06-10 01:27:12 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2009-06-12 21:32:33 +0200
commita9d7052363a6e06bb623ed1876c56c7ca5b2c6d8 (patch)
treec4ec7fb30dc4510596ffc9ddffe308ef34837af2 /kernel/power/suspend.c
parent783ea7d4eeefe895f2731fe73ac951e94418927b (diff)
PM: Separate suspend to RAM functionality from core
Move the suspend to RAM and standby code from kernel/power/main.c to two separate files, kernel/power/suspend.c containing the basic functions and kernel/power/suspend_test.c containing the automatic suspend test facility based on the RTC clock alarm. There are no changes in functionality related to these modifications. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz>
Diffstat (limited to 'kernel/power/suspend.c')
-rw-r--r--kernel/power/suspend.c300
1 files changed, 300 insertions, 0 deletions
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
new file mode 100644
index 000000000000..6f10dfc2d3e9
--- /dev/null
+++ b/kernel/power/suspend.c
@@ -0,0 +1,300 @@
+/*
+ * kernel/power/suspend.c - Suspend to RAM and standby functionality.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/cpu.h>
+#include <linux/syscalls.h>
+
+#include "power.h"
+
+const char *const pm_states[PM_SUSPEND_MAX] = {
+ [PM_SUSPEND_STANDBY] = "standby",
+ [PM_SUSPEND_MEM] = "mem",
+};
+
+static struct platform_suspend_ops *suspend_ops;
+
+/**
+ * suspend_set_ops - Set the global suspend method table.
+ * @ops: Pointer to ops structure.
+ */
+void suspend_set_ops(struct platform_suspend_ops *ops)
+{
+ mutex_lock(&pm_mutex);
+ suspend_ops = ops;
+ mutex_unlock(&pm_mutex);
+}
+
+bool valid_state(suspend_state_t state)
+{
+ /*
+ * All states need lowlevel support and need to be valid to the lowlevel
+ * implementation, no valid callback implies that none are valid.
+ */
+ return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
+}
+
+/**
+ * suspend_valid_only_mem - generic memory-only valid callback
+ *
+ * Platform drivers that implement mem suspend only and only need
+ * to check for that in their .valid callback can use this instead
+ * of rolling their own .valid callback.
+ */
+int suspend_valid_only_mem(suspend_state_t state)
+{
+ return state == PM_SUSPEND_MEM;
+}
+
+static int suspend_test(int level)
+{
+#ifdef CONFIG_PM_DEBUG
+ if (pm_test_level == level) {
+ printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
+ mdelay(5000);
+ return 1;
+ }
+#endif /* !CONFIG_PM_DEBUG */
+ return 0;
+}
+
+/**
+ * suspend_prepare - Do prep work before entering low-power state.
+ *
+ * This is common code that is called for each state that we're entering.
+ * Run suspend notifiers, allocate a console and stop all processes.
+ */
+static int suspend_prepare(void)
+{
+ int error;
+
+ if (!suspend_ops || !suspend_ops->enter)
+ return -EPERM;
+
+ pm_prepare_console();
+
+ error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
+ if (error)
+ goto Finish;
+
+ error = usermodehelper_disable();
+ if (error)
+ goto Finish;
+
+ error = suspend_freeze_processes();
+ if (!error)
+ return 0;
+
+ suspend_thaw_processes();
+ usermodehelper_enable();
+ Finish:
+ pm_notifier_call_chain(PM_POST_SUSPEND);
+ pm_restore_console();
+ return error;
+}
+
+/* default implementation */
+void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
+{
+ local_irq_disable();
+}
+
+/* default implementation */
+void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
+{
+ local_irq_enable();
+}
+
+/**
+ * suspend_enter - enter the desired system sleep state.
+ * @state: state to enter
+ *
+ * This function should be called after devices have been suspended.
+ */
+static int suspend_enter(suspend_state_t state)
+{
+ int error;
+
+ if (suspend_ops->prepare) {
+ error = suspend_ops->prepare();
+ if (error)
+ return error;
+ }
+
+ error = dpm_suspend_noirq(PMSG_SUSPEND);
+ if (error) {
+ printk(KERN_ERR "PM: Some devices failed to power down\n");
+ goto Platfrom_finish;
+ }
+
+ if (suspend_ops->prepare_late) {
+ error = suspend_ops->prepare_late();
+ if (error)
+ goto Power_up_devices;
+ }
+
+ if (suspend_test(TEST_PLATFORM))
+ goto Platform_wake;
+
+ error = disable_nonboot_cpus();
+ if (error || suspend_test(TEST_CPUS))
+ goto Enable_cpus;
+
+ arch_suspend_disable_irqs();
+ BUG_ON(!irqs_disabled());
+
+ error = sysdev_suspend(PMSG_SUSPEND);
+ if (!error) {
+ if (!suspend_test(TEST_CORE))
+ error = suspend_ops->enter(state);
+ sysdev_resume();
+ }
+
+ arch_suspend_enable_irqs();
+ BUG_ON(irqs_disabled());
+
+ Enable_cpus:
+ enable_nonboot_cpus();
+
+ Platform_wake:
+ if (suspend_ops->wake)
+ suspend_ops->wake();
+
+ Power_up_devices:
+ dpm_resume_noirq(PMSG_RESUME);
+
+ Platfrom_finish:
+ if (suspend_ops->finish)
+ suspend_ops->finish();
+
+ return error;
+}
+
+/**
+ * suspend_devices_and_enter - suspend devices and enter the desired system
+ * sleep state.
+ * @state: state to enter
+ */
+int suspend_devices_and_enter(suspend_state_t state)
+{
+ int error;
+
+ if (!suspend_ops)
+ return -ENOSYS;
+
+ if (suspend_ops->begin) {
+ error = suspend_ops->begin(state);
+ if (error)
+ goto Close;
+ }
+ suspend_console();
+ suspend_test_start();
+ error = dpm_suspend_start(PMSG_SUSPEND);
+ if (error) {
+ printk(KERN_ERR "PM: Some devices failed to suspend\n");
+ goto Recover_platform;
+ }
+ suspend_test_finish("suspend devices");
+ if (suspend_test(TEST_DEVICES))
+ goto Recover_platform;
+
+ suspend_enter(state);
+
+ Resume_devices:
+ suspend_test_start();
+ dpm_resume_end(PMSG_RESUME);
+ suspend_test_finish("resume devices");
+ resume_console();
+ Close:
+ if (suspend_ops->end)
+ suspend_ops->end();
+ return error;
+
+ Recover_platform:
+ if (suspend_ops->recover)
+ suspend_ops->recover();
+ goto Resume_devices;
+}
+
+/**
+ * suspend_finish - Do final work before exiting suspend sequence.
+ *
+ * Call platform code to clean up, restart processes, and free the
+ * console that we've allocated. This is not called for suspend-to-disk.
+ */
+static void suspend_finish(void)
+{
+ suspend_thaw_processes();
+ usermodehelper_enable();
+ pm_notifier_call_chain(PM_POST_SUSPEND);
+ pm_restore_console();
+}
+
+/**
+ * enter_state - Do common work of entering low-power state.
+ * @state: pm_state structure for state we're entering.
+ *
+ * Make sure we're the only ones trying to enter a sleep state. Fail
+ * if someone has beat us to it, since we don't want anything weird to
+ * happen when we wake up.
+ * Then, do the setup for suspend, enter the state, and cleaup (after
+ * we've woken up).
+ */
+int enter_state(suspend_state_t state)
+{
+ int error;
+
+ if (!valid_state(state))
+ return -ENODEV;
+
+ if (!mutex_trylock(&pm_mutex))
+ return -EBUSY;
+
+ printk(KERN_INFO "PM: Syncing filesystems ... ");
+ sys_sync();
+ printk("done.\n");
+
+ pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
+ error = suspend_prepare();
+ if (error)
+ goto Unlock;
+
+ if (suspend_test(TEST_FREEZER))
+ goto Finish;
+
+ pr_debug("PM: Entering %s sleep\n", pm_states[state]);
+ error = suspend_devices_and_enter(state);
+
+ Finish:
+ pr_debug("PM: Finishing wakeup.\n");
+ suspend_finish();
+ Unlock:
+ mutex_unlock(&pm_mutex);
+ return error;
+}
+
+/**
+ * pm_suspend - Externally visible function for suspending system.
+ * @state: Enumerated value of state to enter.
+ *
+ * Determine whether or not value is within range, get state
+ * structure, and enter (above).
+ */
+int pm_suspend(suspend_state_t state)
+{
+ if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
+ return enter_state(state);
+ return -EINVAL;
+}
+EXPORT_SYMBOL(pm_suspend);