[RFC][PATCH -mm 4/5] swsusp: Add PLATFORM_SNAPSHOT and PLATFORM_RESTORE ioctls

Rafael J. Wysocki
2006-11-25T21:45:28Z

Since pm_ops->finish() has to be called after enable_nonboot_cpus() and before
device_resume(), from the userland interface perspective it should be treated
as a part of the atomic suspend and resume operations. For this reason we
need two additional ioctls to be called instead of ATOMIC_SNAPSHOT and
ATOMIC_RESTORE, respectively, when the platform suspend mode is to be used.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
kernel/power/power.h | 4 ++
kernel/power/user.c | 71 +++++++++++++++++++++++++++++++++++++++++++--------
2 files changed, 64 insertions(+), 11 deletions(-)

Index: linux-2.6.19-rc6-mm1/kernel/power/power.h
===================================================================
--- linux-2.6.19-rc6-mm1.orig/kernel/power/power.h
+++ linux-2.6.19-rc6-mm1/kernel/power/power.h
@@ -133,7 +133,9 @@ struct resume_swap_area {
#define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
#define SNAPSHOT_SET_SWAP_AREA _IOW(SNAPSHOT_IOC_MAGIC, 13, \
struct resume_swap_area)
-#define SNAPSHOT_IOC_MAXNR 13
+#define SNAPSHOT_PLATFORM_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 14, unsigned int)
+#define SNAPSHOT_PLATFORM_RESTORE _IO(SNAPSHOT_IOC_MAGIC, 15)
+#define SNAPSHOT_IOC_MAXNR 15

#define PMOPS_PREPARE 1
#define PMOPS_ENTER 2
Index: linux-2.6.19-rc6-mm1/kernel/power/user.c
===================================================================
--- linux-2.6.19-rc6-mm1.orig/kernel/power/user.c
+++ linux-2.6.19-rc6-mm1/kernel/power/user.c
@@ -122,7 +122,23 @@ static ssize_t snapshot_write(struct fil
return res;
}

-static int snapshot_suspend(void)
+static inline int platform_prepare(void)
+{
+ int error = 0;
+
+ if (pm_ops && pm_ops->prepare)
+ error = pm_ops->prepare(PM_SUSPEND_DISK);
+
+ return error;
+}
+
+static inline void platform_finish(void)
+{
+ if (pm_ops && pm_ops->finish)
+ pm_ops->finish(PM_SUSPEND_DISK);
+}
+
+static int snapshot_suspend(int platform_mode)
{
int error;

@@ -132,6 +148,11 @@ static int snapshot_suspend(void)
if (error)
goto Finish;

+ if (platform_mode) {
+ error = platform_prepare();
+ if (error)
+ goto Finish;
+ }
suspend_console();
error = device_suspend(PMSG_FREEZE);
if (error)
@@ -144,6 +165,9 @@ static int snapshot_suspend(void)
}
enable_nonboot_cpus();
Resume_devices:
+ if (platform_mode)
+ platform_finish();
+
device_resume();
resume_console();
Finish:
@@ -151,12 +175,17 @@ static int snapshot_suspend(void)
return error;
}

-static int snapshot_restore(void)
+static int snapshot_restore(int platform_mode)
{
int error;

mutex_lock(&pm_mutex);
pm_prepare_console();
+ if (platform_mode) {
+ error = platform_prepare();
+ if (error)
+ goto Finish;
+ }
suspend_console();
error = device_suspend(PMSG_PRETHAW);
if (error)
@@ -168,8 +197,12 @@ static int snapshot_restore(void)

enable_nonboot_cpus();
Resume_devices:
+ if (platform_mode)
+ platform_finish();
+
device_resume();
resume_console();
+ Finish:
pm_restore_console();
mutex_unlock(&pm_mutex);
return error;
@@ -221,7 +254,7 @@ static int snapshot_ioctl(struct inode *
error = -EPERM;
break;
}
- error = snapshot_suspend();
+ error = snapshot_suspend(0);
if (!error)
error = put_user(in_suspend, (unsigned int __user *)arg);
if (!error)
@@ -235,7 +268,7 @@ static int snapshot_ioctl(struct inode *
error = -EPERM;
break;
}
- error = snapshot_restore();
+ error = snapshot_restore(0);
break;

case SNAPSHOT_FREE:
@@ -345,9 +378,7 @@ static int snapshot_ioctl(struct inode *
switch (arg) {

case PMOPS_PREPARE:
- if (pm_ops->prepare) {
- error = pm_ops->prepare(PM_SUSPEND_DISK);
- }
+ error = platform_prepare();
break;

case PMOPS_ENTER:
@@ -356,9 +387,7 @@ static int snapshot_ioctl(struct inode *
break;

case PMOPS_FINISH:
- if (pm_ops && pm_ops->finish) {
- pm_ops->finish(PM_SUSPEND_DISK);
- }
+ platform_finish();
break;

default:
@@ -399,6 +428,28 @@ static int snapshot_ioctl(struct inode *
}
break;

+ case SNAPSHOT_PLATFORM_SNAPSHOT:
+ if (data->mode != O_RDONLY || !data->frozen || data->ready) {
+ error = -EPERM;
+ break;
+ }
+ error = snapshot_suspend(1);
+ if (!error)
+ error = put_user(in_suspend, (unsigned int __user *)arg);
+ if (!error)
+ data->ready = 1;
+ break;
+
+ case SNAPSHOT_PLATFORM_RESTORE:
+ snapshot_write_finalize(&data->handle);
+ if (data->mode != O_WRONLY || !data->frozen ||
+ !snapshot_image_loaded(&data->handle)) {
+ error = -EPERM;
+ break;
+ }
+ error = snapshot_restore(1);
+ break;
+
default:
error = -ENOTTY;