Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.

[akpm@osdl.org: fix ueagle driver]
Signed-off-by: NNigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently swsusp saves the contents of highmem pages by copying them to the
normal zone which is quite inefficient (eg.  it requires two normal pages
to be used for saving one highmem page).  This may be improved by using
highmem for saving the contents of saveable highmem pages.

Namely, during the suspend phase of the suspend-resume cycle we try to
allocate as many free highmem pages as there are saveable highmem pages.
If there are not enough highmem image pages to store the contents of all of
the saveable highmem pages, some of them will be stored in the "normal"
memory.  Next, we allocate as many free "normal" pages as needed to store
the (remaining) image data.  We use a memory bitmap to mark the allocated
free pages (ie.  highmem as well as "normal" image pages).

Now, we use another memory bitmap to mark all of the saveable pages
(highmem as well as "normal") and the contents of the saveable pages are
copied into the image pages.  Then, the second bitmap is used to save the
pfns corresponding to the saveable pages and the first one is used to save
their data.

During the resume phase the pfns of the pages that were saveable during the
suspend are loaded from the image and used to mark the "unsafe" page
frames.  Next, we try to allocate as many free highmem page frames as to
load all of the image data that had been in the highmem before the suspend
and we allocate so many free "normal" page frames that the total number of
allocated free pages (highmem and "normal") is equal to the size of the
image.  While doing this we have to make sure that there will be some extra
free "normal" and "safe" page frames for two lists of PBEs constructed
later.

Now, the image data are loaded, if possible, into their "original" page
frames.  The image data that cannot be written into their "original" page
frames are loaded into "safe" page frames and their "original" kernel
virtual addresses, as well as the addresses of the "safe" pages containing
their copies, are stored in one of two lists of PBEs.

One list of PBEs is for the copies of "normal" suspend pages (ie.  "normal"
pages that were saveable during the suspend) and it is used in the same way
as previously (ie.  by the architecture-dependent parts of swsusp).  The
other list of PBEs is for the copies of highmem suspend pages.  The pages
in this list are restored (in a reversible way) right before the
arch-dependent code is called.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

To be able to use swap files as suspend storage from the userland suspend
tools we need an additional ioctl() that will allow us to provide the kernel
with both the swap header's offset and the identification of the resume
partition.

The new ioctl() should be regarded as a replacement for the
SNAPSHOT_SET_SWAP_FILE ioctl() that from now on will be considered as
obsolete, but has to stay for backwards compatibility of the interface.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make swsusp use block device offsets instead of swap offsets to identify swap
locations and make it use the same code paths for writing as well as for
reading data.

This allows us to use the same code for handling swap files and swap
partitions and to simplify the code, eg.  by dropping rw_swap_page_sync().
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The Linux kernel handles swap files almost in the same way as it handles swap
partitions and there are only two differences between these two types of swap
areas:

(1) swap files need not be contiguous,

(2) the header of a swap file is not in the first block of the partition
    that holds it.  From the swsusp's point of view (1) is not a problem,
    because it is already taken care of by the swap-handling code, but (2) has
    to be taken into consideration.

In principle the location of a swap file's header may be determined with the
help of appropriate filesystem driver.  Unfortunately, however, it requires
the filesystem holding the swap file to be mounted, and if this filesystem is
journaled, it cannot be mounted during a resume from disk.  For this reason we
need some other means by which swap areas can be identified.

For example, to identify a swap area we can use the partition that holds the
area and the offset from the beginning of this partition at which the swap
header is located.

The following patch allows swsusp to identify swap areas this way.  It changes
swap_type_of() so that it takes an additional argument representing an offset
of the swap header within the partition represented by its first argument.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add an ioctl to the userspace swsusp code that enables the usage of the
pmops->prepare, pmops->enter and pmops->finish methods (the in-kernel
suspend knows these as "platform method").  These are needed on many
machines to (among others) speed up resuming by letting the BIOS skip some
steps or let my hp nx5000 recognise the correct ac_adapter state after
resume again.

It also ensures on many machines, that changed hardware (unplugged AC
adapters) gets correctly detected and that kacpid does not run wild after
resume.
Signed-off-by: NStefan Seyfried <seife@suse.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add suspend_console() and resume_console() to the suspend-to-disk code paths
so that the users of netconsole can use swsusp with it.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Unfortunately one of the recent changes in swsusp has broken the userland
suspend on SMP.  Fix it.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make swsusp use memory bitmaps to store its internal information during the
resume phase of the suspend-resume cycle.

If the pfns of saveable pages are saved during the suspend phase instead of
the kernel virtual addresses of these pages, we can use them during the resume
phase directly to set the corresponding bits in a memory bitmap.  Then, this
bitmap is used to mark the page frames corresponding to the pages that were
saveable before the suspend (aka "unsafe" page frames).

Next, we allocate as many page frames as needed to store the entire suspend
image and make sure that there will be some extra free "safe" page frames for
the list of PBEs constructed later.  Subsequently, the image is loaded and, if
possible, the data loaded from it are written into their "original" page
frames (ie.  the ones they had occupied before the suspend).

The image data that cannot be written into their "original" page frames are
loaded into "safe" page frames and their "original" kernel virtual addresses,
as well as the addresses of the "safe" pages containing their copies, are
stored in a list of PBEs.  Finally, the list of PBEs is used to copy the
remaining image data into their "original" page frames (this is done
atomically, by the architecture-dependent parts of swsusp).
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The current suspend code has to be run on one CPU, so we use the CPU
hotplug to take the non-boot CPUs offline on SMP machines.  However, we
should also make sure that these CPUs will not be enabled by someone else
after we have disabled them.

The functions disable_nonboot_cpus() and enable_nonboot_cpus() are moved to
kernel/cpu.c, because they now refer to some stuff in there that should
better be static.  Also it's better if disable_nonboot_cpus() returns an
error instead of panicking if something goes wrong, and
enable_nonboot_cpus() has no reason to panic(), because the CPUs may have
been enabled by the userland before it tries to take them online.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch is the first of this series that should actually change any
behavior ...  by issuing the new event, now tha the rest of the kernel is
prepared to receive it.

This converts the PM core to issue the new PRETHAW message, which the rest of
the kernel is now ready to receive.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

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: NLuca Tettamanti <kronos.it@gmail.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove the console-switching code from the suspend part of the swsusp userland
interface and let the userland tools switch the console.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Allow swsusp to freeze processes successfully under heavy load by freezing
userspace processes before kernel threads.

[Thanks to Nigel Cunningham <nigel@suspend2.net> for suggesting the
way to go.]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch introduces a user space interface for swsusp.

The interface is based on a special character device, called the snapshot
device, that allows user space processes to perform suspend and resume-related
operations with the help of some ioctls and the read()/write() functions.
 Additionally it allows these processes to allocate free swap pages from a
selected swap partition, called the resume partition, so that they know which
sectors of the resume partition are available to them.

The interface uses the same low-level system memory snapshot-handling
functions that are used by the built-it swap-writing/reading code of swsusp.

The interface documentation is included in the patch.

The patch assumes that the major and minor numbers of the snapshot device will
be 10 (ie.  misc device) and 231, the registration of which has already been
requested.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>