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>

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);