[PATCH] swsusp: add s2ram ioctl to userland interface

Add the SNAPSHOT_S2RAM ioctl to the snapshot device.

This ioctl allows a userland application to make the system (previously frozen
with the SNAPSHOT_FREE ioctl) enter the S3 state without freezing processes
and disabling nonboot CPUs for the second time.

This will allow us to implement the suspend-to-disk-and-RAM (STDR)
functionality in the userland suspend tools.

Signed-off-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/kernel/power/user.c b/kernel/power/user.c
index bbd4842104aa..3f1539fbe48a 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -266,6 +266,42 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
                 }
                 break;
 
+        case SNAPSHOT_S2RAM:
+                if (!data->frozen) {
+                        error = -EPERM;
+                        break;
+                }
+
+                if (down_trylock(&pm_sem)) {
+                        error = -EBUSY;
+                        break;
+                }
+
+                if (pm_ops->prepare) {
+                        error = pm_ops->prepare(PM_SUSPEND_MEM);
+                        if (error)
+                                goto OutS3;
+                }
+
+                /* Put devices to sleep */
+                error = device_suspend(PMSG_SUSPEND);
+                if (error) {
+                        printk(KERN_ERR "Failed to suspend some devices.\n");
+                } else {
+                        /* Enter S3, system is already frozen */
+                        suspend_enter(PM_SUSPEND_MEM);
+
+                        /* Wake up devices */
+                        device_resume();
+                }
+
+                if (pm_ops->finish)
+                        pm_ops->finish(PM_SUSPEND_MEM);
+
+OutS3:
+                up(&pm_sem);
+                break;
+
         default:
                 error = -ENOTTY;