#include "power.h"
+/*This is just an arbitrary number */
+#define FREE_PAGE_NUMBER (100)
+
DECLARE_MUTEX(pm_sem);
-struct pm_ops * pm_ops = NULL;
+struct pm_ops *pm_ops;
suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN;
/**
static int suspend_prepare(suspend_state_t state)
{
int error = 0;
+ unsigned int free_pages;
if (!pm_ops || !pm_ops->enter)
return -EPERM;
pm_prepare_console();
+ disable_nonboot_cpus();
+
+ if (num_online_cpus() != 1) {
+ error = -EPERM;
+ goto Enable_cpu;
+ }
+
if (freeze_processes()) {
error = -EAGAIN;
goto Thaw;
}
+ if ((free_pages = nr_free_pages()) < FREE_PAGE_NUMBER) {
+ pr_debug("PM: free some memory\n");
+ shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
+ if (nr_free_pages() < FREE_PAGE_NUMBER) {
+ error = -ENOMEM;
+ printk(KERN_ERR "PM: No enough memory\n");
+ goto Thaw;
+ }
+ }
+
if (pm_ops->prepare) {
if ((error = pm_ops->prepare(state)))
goto Thaw;
pm_ops->finish(state);
Thaw:
thaw_processes();
+ Enable_cpu:
+ enable_nonboot_cpus();
pm_restore_console();
return error;
}
-static int suspend_enter(suspend_state_t state)
+int suspend_enter(suspend_state_t state)
{
int error = 0;
unsigned long flags;
static void suspend_finish(suspend_state_t state)
{
device_resume();
+ thaw_processes();
+ enable_nonboot_cpus();
if (pm_ops && pm_ops->finish)
pm_ops->finish(state);
- thaw_processes();
pm_restore_console();
}
-static char * pm_states[] = {
+static char *pm_states[PM_SUSPEND_MAX] = {
[PM_SUSPEND_STANDBY] = "standby",
[PM_SUSPEND_MEM] = "mem",
+#ifdef CONFIG_SOFTWARE_SUSPEND
[PM_SUSPEND_DISK] = "disk",
- NULL,
+#endif
};
+static inline int valid_state(suspend_state_t state)
+{
+ /* Suspend-to-disk does not really need low-level support.
+ * It can work with reboot if needed. */
+ if (state == PM_SUSPEND_DISK)
+ return 1;
+
+ if (pm_ops && pm_ops->valid && !pm_ops->valid(state))
+ return 0;
+ return 1;
+}
+
/**
* enter_state - Do common work of entering low-power state.
{
int error;
+ if (!valid_state(state))
+ return -ENODEV;
if (down_trylock(&pm_sem))
return -EBUSY;
goto Unlock;
}
- /* Suspend is hard to get right on SMP. */
- if (num_online_cpus() != 1) {
- error = -EPERM;
- goto Unlock;
- }
-
pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
if ((error = suspend_prepare(state)))
goto Unlock;
int pm_suspend(suspend_state_t state)
{
- if (state > PM_SUSPEND_ON && state < PM_SUSPEND_MAX)
+ if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
return enter_state(state);
return -EINVAL;
}
char * s = buf;
for (i = 0; i < PM_SUSPEND_MAX; i++) {
- if (pm_states[i])
- s += sprintf(s,"%s ",pm_states[i]);
+ if (pm_states[i] && valid_state(i))
+ s += sprintf(s,"%s ", pm_states[i]);
}
s += sprintf(s,"\n");
return (s - buf);
if (*s && !strncmp(buf, *s, len))
break;
}
- if (*s)
+ if (state < PM_SUSPEND_MAX && *s)
error = enter_state(state);
else
error = -EINVAL;