[PATCH] introduce .valid callback for pm_ops

[karo-tx-linux.git] / kernel / power / main.c

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 4cdebc972ff2a55c7fdac702dca0c36f81905558..18d7d693fbba852c48acc40de4ad8809baf5d36e 100644 (file)
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -19,6 +19,9 @@
 
 #include "power.h"
 
+/*This is just an arbitrary number */
+#define FREE_PAGE_NUMBER (100)
+
 DECLARE_MUTEX(pm_sem);
 
 struct pm_ops * pm_ops = NULL;
@@ -49,17 +52,35 @@ void pm_set_ops(struct pm_ops * ops)
 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;
@@ -75,6 +96,8 @@ static int suspend_prepare(suspend_state_t state)
                pm_ops->finish(state);
  Thaw:
        thaw_processes();
+ Enable_cpu:
+       enable_nonboot_cpus();
        pm_restore_console();
        return error;
 }
@@ -113,17 +136,19 @@ static void suspend_finish(suspend_state_t state)
        if (pm_ops && pm_ops->finish)
                pm_ops->finish(state);
        thaw_processes();
+       enable_nonboot_cpus();
        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
 };
 
 
@@ -142,6 +167,8 @@ static int enter_state(suspend_state_t state)
 {
        int error;
 
+       if (pm_ops->valid && !pm_ops->valid(state))
+               return -ENODEV;
        if (down_trylock(&pm_sem))
                return -EBUSY;
 
@@ -150,12 +177,6 @@ static int enter_state(suspend_state_t state)
                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;
@@ -190,7 +211,7 @@ int software_suspend(void)
 
 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;
 }
@@ -217,7 +238,8 @@ static ssize_t state_show(struct subsystem * subsys, char * buf)
        char * s = buf;
 
        for (i = 0; i < PM_SUSPEND_MAX; i++) {
-               if (pm_states[i])
+               if (pm_states[i] && pm_ops && (!pm_ops->valid
+                       ||(pm_ops->valid && pm_ops->valid(i))))
                        s += sprintf(s,"%s ",pm_states[i]);
        }
        s += sprintf(s,"\n");