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-rw-r--r--Documentation/ABI/testing/sysfs-power14
-rw-r--r--Documentation/power/swsusp.txt10
-rw-r--r--kernel/power/hibernate.c24
3 files changed, 47 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
index 1e0d1dac706b..2f813d644c69 100644
--- a/Documentation/ABI/testing/sysfs-power
+++ b/Documentation/ABI/testing/sysfs-power
@@ -287,3 +287,17 @@ Description:
Writing a "1" to this file enables the debug messages and
writing a "0" (default) to it disables them. Reads from
this file return the current value.
+
+What: /sys/power/resume_offset
+Date: April 2018
+Contact: Mario Limonciello <mario.limonciello@dell.com>
+Description:
+ This file is used for telling the kernel an offset into a disk
+ to use when hibernating the system such as with a swap file.
+
+ Reads from this file will display the current offset
+ the kernel will be using on the next hibernation
+ attempt.
+
+ Using this sysfs file will override any values that were
+ set using the kernel command line for disk offset. \ No newline at end of file
diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
index 9f2f942a01cf..cc87adf44c0a 100644
--- a/Documentation/power/swsusp.txt
+++ b/Documentation/power/swsusp.txt
@@ -24,8 +24,16 @@ Some warnings, first.
* see the FAQ below for details. (This is not true for more traditional
* power states like "standby", which normally don't turn USB off.)
+Swap partition:
You need to append resume=/dev/your_swap_partition to kernel command
-line. Then you suspend by
+line or specify it using /sys/power/resume.
+
+Swap file:
+If using a swapfile you can also specify a resume offset using
+resume_offset=<number> on the kernel command line or specify it
+in /sys/power/resume_offset.
+
+After preparing then you suspend by
echo shutdown > /sys/power/disk; echo disk > /sys/power/state
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index a5c36e9c56a6..d58fad3db22d 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -1061,6 +1061,29 @@ static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
power_attr(resume);
+static ssize_t resume_offset_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
+}
+
+static ssize_t resume_offset_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf,
+ size_t n)
+{
+ unsigned long long offset;
+ int rc;
+
+ rc = kstrtoull(buf, 0, &offset);
+ if (rc)
+ return rc;
+ swsusp_resume_block = offset;
+
+ return n;
+}
+
+power_attr(resume_offset);
+
static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
@@ -1106,6 +1129,7 @@ power_attr(reserved_size);
static struct attribute * g[] = {
&disk_attr.attr,
+ &resume_offset_attr.attr,
&resume_attr.attr,
&image_size_attr.attr,
&reserved_size_attr.attr,