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authorRafael J. Wysocki <rjw@sisk.pl>2007-10-25 19:03:33 -0400
committerLen Brown <len.brown@intel.com>2008-02-01 18:30:53 -0500
commitcc5d207c85b9a6fafebe2856ead0a9360978c8cd (patch)
tree1a7c45b4ffb44a02a76ccd60ec318c796687d568 /Documentation/power/userland-swsusp.txt
parent96f737490cfc368fdafe49769f52fc8460f9349f (diff)
Hibernation: Correct definitions of some ioctls (rev. 2)
Three ioctl numbers belonging to the hibernation userland interface, SNAPSHOT_ATOMIC_SNAPSHOT, SNAPSHOT_AVAIL_SWAP, SNAPSHOT_GET_SWAP_PAGE, are defined in a wrong way (eg. not portable). Provide new ioctl numbers for these ioctls and mark the existing ones as deprecated. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'Documentation/power/userland-swsusp.txt')
-rw-r--r--Documentation/power/userland-swsusp.txt26
1 files changed, 13 insertions, 13 deletions
diff --git a/Documentation/power/userland-swsusp.txt b/Documentation/power/userland-swsusp.txt
index 0785500e65fb..af52d535a896 100644
--- a/Documentation/power/userland-swsusp.txt
+++ b/Documentation/power/userland-swsusp.txt
@@ -27,17 +27,17 @@ once at a time.
27The ioctl() commands recognized by the device are: 27The ioctl() commands recognized by the device are:
28 28
29SNAPSHOT_FREEZE - freeze user space processes (the current process is 29SNAPSHOT_FREEZE - freeze user space processes (the current process is
30 not frozen); this is required for SNAPSHOT_ATOMIC_SNAPSHOT 30 not frozen); this is required for SNAPSHOT_CREATE_IMAGE
31 and SNAPSHOT_ATOMIC_RESTORE to succeed 31 and SNAPSHOT_ATOMIC_RESTORE to succeed
32 32
33SNAPSHOT_UNFREEZE - thaw user space processes frozen by SNAPSHOT_FREEZE 33SNAPSHOT_UNFREEZE - thaw user space processes frozen by SNAPSHOT_FREEZE
34 34
35SNAPSHOT_ATOMIC_SNAPSHOT - create a snapshot of the system memory; the 35SNAPSHOT_CREATE_IMAGE - create a snapshot of the system memory; the
36 last argument of ioctl() should be a pointer to an int variable, 36 last argument of ioctl() should be a pointer to an int variable,
37 the value of which will indicate whether the call returned after 37 the value of which will indicate whether the call returned after
38 creating the snapshot (1) or after restoring the system memory state 38 creating the snapshot (1) or after restoring the system memory state
39 from it (0) (after resume the system finds itself finishing the 39 from it (0) (after resume the system finds itself finishing the
40 SNAPSHOT_ATOMIC_SNAPSHOT ioctl() again); after the snapshot 40 SNAPSHOT_CREATE_IMAGE ioctl() again); after the snapshot
41 has been created the read() operation can be used to transfer 41 has been created the read() operation can be used to transfer
42 it out of the kernel 42 it out of the kernel
43 43
@@ -49,23 +49,23 @@ SNAPSHOT_ATOMIC_RESTORE - restore the system memory state from the
49 49
50SNAPSHOT_FREE - free memory allocated for the snapshot image 50SNAPSHOT_FREE - free memory allocated for the snapshot image
51 51
52SNAPSHOT_SET_IMAGE_SIZE - set the preferred maximum size of the image 52SNAPSHOT_PREF_IMAGE_SIZE - set the preferred maximum size of the image
53 (the kernel will do its best to ensure the image size will not exceed 53 (the kernel will do its best to ensure the image size will not exceed
54 this number, but if it turns out to be impossible, the kernel will 54 this number, but if it turns out to be impossible, the kernel will
55 create the smallest image possible) 55 create the smallest image possible)
56 56
57SNAPSHOT_GET_IMAGE_SIZE - return the actual size of the hibernation image 57SNAPSHOT_GET_IMAGE_SIZE - return the actual size of the hibernation image
58 58
59SNAPSHOT_AVAIL_SWAP - return the amount of available swap in bytes (the last 59SNAPSHOT_AVAIL_SWAP_SIZE - return the amount of available swap in bytes (the
60 argument should be a pointer to an unsigned int variable that will 60 last argument should be a pointer to an unsigned int variable that will
61 contain the result if the call is successful). 61 contain the result if the call is successful).
62 62
63SNAPSHOT_GET_SWAP_PAGE - allocate a swap page from the resume partition 63SNAPSHOT_ALLOC_SWAP_PAGE - allocate a swap page from the resume partition
64 (the last argument should be a pointer to a loff_t variable that 64 (the last argument should be a pointer to a loff_t variable that
65 will contain the swap page offset if the call is successful) 65 will contain the swap page offset if the call is successful)
66 66
67SNAPSHOT_FREE_SWAP_PAGES - free all swap pages allocated with 67SNAPSHOT_FREE_SWAP_PAGES - free all swap pages allocated by
68 SNAPSHOT_GET_SWAP_PAGE 68 SNAPSHOT_ALLOC_SWAP_PAGE
69 69
70SNAPSHOT_SET_SWAP_AREA - set the resume partition and the offset (in <PAGE_SIZE> 70SNAPSHOT_SET_SWAP_AREA - set the resume partition and the offset (in <PAGE_SIZE>
71 units) from the beginning of the partition at which the swap header is 71 units) from the beginning of the partition at which the swap header is
@@ -102,7 +102,7 @@ The device's write() operation is used for uploading the system memory snapshot
102into the kernel. It has the same limitations as the read() operation. 102into the kernel. It has the same limitations as the read() operation.
103 103
104The release() operation frees all memory allocated for the snapshot image 104The release() operation frees all memory allocated for the snapshot image
105and all swap pages allocated with SNAPSHOT_GET_SWAP_PAGE (if any). 105and all swap pages allocated with SNAPSHOT_ALLOC_SWAP_PAGE (if any).
106Thus it is not necessary to use either SNAPSHOT_FREE or 106Thus it is not necessary to use either SNAPSHOT_FREE or
107SNAPSHOT_FREE_SWAP_PAGES before closing the device (in fact it will also 107SNAPSHOT_FREE_SWAP_PAGES before closing the device (in fact it will also
108unfreeze user space processes frozen by SNAPSHOT_UNFREEZE if they are 108unfreeze user space processes frozen by SNAPSHOT_UNFREEZE if they are
@@ -113,7 +113,7 @@ snapshot image from/to the kernel will use a swap parition, called the resume
113partition, or a swap file as storage space (if a swap file is used, the resume 113partition, or a swap file as storage space (if a swap file is used, the resume
114partition is the partition that holds this file). However, this is not really 114partition is the partition that holds this file). However, this is not really
115required, as they can use, for example, a special (blank) suspend partition or 115required, as they can use, for example, a special (blank) suspend partition or
116a file on a partition that is unmounted before SNAPSHOT_ATOMIC_SNAPSHOT and 116a file on a partition that is unmounted before SNAPSHOT_CREATE_IMAGE and
117mounted afterwards. 117mounted afterwards.
118 118
119These utilities MUST NOT make any assumptions regarding the ordering of 119These utilities MUST NOT make any assumptions regarding the ordering of
@@ -135,7 +135,7 @@ means, such as checksums, to ensure the integrity of the snapshot image.
135The suspending and resuming utilities MUST lock themselves in memory, 135The suspending and resuming utilities MUST lock themselves in memory,
136preferrably using mlockall(), before calling SNAPSHOT_FREEZE. 136preferrably using mlockall(), before calling SNAPSHOT_FREEZE.
137 137
138The suspending utility MUST check the value stored by SNAPSHOT_ATOMIC_SNAPSHOT 138The suspending utility MUST check the value stored by SNAPSHOT_CREATE_IMAGE
139in the memory location pointed to by the last argument of ioctl() and proceed 139in the memory location pointed to by the last argument of ioctl() and proceed
140in accordance with it: 140in accordance with it:
1411. If the value is 1 (ie. the system memory snapshot has just been 1411. If the value is 1 (ie. the system memory snapshot has just been
@@ -149,7 +149,7 @@ in accordance with it:
149 image has been saved. 149 image has been saved.
150 (b) The suspending utility SHOULD NOT attempt to perform any 150 (b) The suspending utility SHOULD NOT attempt to perform any
151 file system operations (including reads) on the file systems 151 file system operations (including reads) on the file systems
152 that were mounted before SNAPSHOT_ATOMIC_SNAPSHOT has been 152 that were mounted before SNAPSHOT_CREATE_IMAGE has been
153 called. However, it MAY mount a file system that was not 153 called. However, it MAY mount a file system that was not
154 mounted at that time and perform some operations on it (eg. 154 mounted at that time and perform some operations on it (eg.
155 use it for saving the image). 155 use it for saving the image).