The alignment is missing for various global symbols in s390 assembly code.
With a recent gcc and an instruction like stgrl this can lead to a
specification exception if the instruction uses such a mis-aligned address.

Specify the alignment explicitely and while add it define __ALIGN for s390
and use the ENTRY define to save some lines of code.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Reenable multiple subchannel sets after hibernation,
prior to the device callbacks.

Cc: <stable@kernel.org>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Rename __LC_RESTART_PSW to __LC_RST_NEW_PSW, add a define for the
missing 32 bit variant and the missing old PSWs.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

sigp sense only returns the status of a cpu if it is non zero. If the
status of the sensed cpu is all zeros condition code 0 (accpeted) is
set and no status bits are returned.
The current code however assumes that a status was returned and tests
bits in it. This means uninitalized data is accessed with random
results.
Worst case is that the code that checks if cpu is offline on cpu
hotplug assumes that the target cpu is offline while it is still
running. This leads potentially to memory corruption since resources
that are still needed by the target cpu will be freed and could be
resused while still in use.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

According to the architecture a cpu must not necessarily enter stopped
state after completion of a sigp instruction with "stop" order code.
So remove the BUG() statement after self sending sigp stop to avoid
that it ever gets reached.
Also add a sigp busy check to make sure that the order gets delivered.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We used address 0x1084 instead of 0x84 to store the suspend CPU address.
With this patch we use the correct address 0x84 as it is defined in
the POP.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The time a system has been suspended should not show up in any
of the cputime accounting fields. The time of inactivity is definitly
not any form of real cputime nor is it idle time.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Currently, when the physical resume CPU is not equal to the physical suspend
CPU, we swap the CPUs logically, by modifying the logical/physical CPU mapping.
This has two major drawbacks: First the change is visible from user space (e.g.
CPU sysfs files) and second it is hard to ensure that nowhere in the kernel
the physical CPU ID is stored before suspend.
To fix this, we now really swap the physical CPUs, if the resume CPU is not
the pysical suspend CPU. We restart the suspend CPU and stop the resume CPU
using SIGP restart and SIGP stop. If the suspend CPU is no longer available,
we write a message and load a disabled wait PSW.
Signed-off-by: NMichael Holzheu <michael.holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Force system into defined state after resume.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

On resume the system that loads the to be resumed image might have
unstable pages.
When the resume image is copied back and a write access happen to an
unstable page this causes an exception and the system crashes.

To fix this set all free pages to stable before copying the resumed
image data. Also after everything has been restored set all free
pages of the resumed system to unstable again.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Merge the nearly empty C files and move everything from power/ to
kernel/. That way the files are easier to handle.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

swsusp_arch_suspend() actually saves all cpu register contents on
hibernation.
Machine checks must be disabled since swsusp_arch_suspend() stores
register contents to their lowcore save areas. That's the same
place where register contents on machine checks would be saved.
To avoid register corruption disable machine checks.
We must also disable machine checks in the new psw mask for
program checks, since swsusp_arch_suspend() may generate program
checks.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Our swsusp_arch_suspend() backend implementation disables prefixing
by setting the contents of the prefix register to 0.
However afterwards common code functions are called which might
access percpu data structures.
Since the lowcore contains e.g. the percpu base pointer this isn't
a good idea. So fix this by copying the hibernating cpu's lowcore to
absolute address zero.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix build error for !SMP:

arch/s390/power/built-in.o: In function `swsusp_arch_resume':
(.text+0x1b4): undefined reference to `smp_get_phys_cpu_id'
arch/s390/power/built-in.o: In function `swsusp_arch_resume':
(.text+0x288): undefined reference to `smp_switch_boot_cpu_in_resume'
make: *** [.tmp_vmlinux1] Error 1
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch introduces the hibernation backend support to the
s390 architecture. Now it is possible to suspend a mainframe Linux
guest using the following command:

echo disk > /sys/power/state
Signed-off-by: NHans-Joachim Picht <hans@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>