linux-toradex.git/arch/s390/kernel/machine_kexec.c, branch v4.3.1

s390: add SMT support

2015-01-22T11:16:01+00:00

The multi-threading facility is introduced with the z13 processor family.
This patch adds code to detect the multi-threading facility. With the
facility enabled each core will surface multiple hardware threads to the
system. Each hardware threads looks like a normal CPU to the operating
system with all its registers and properties.

The SCLP interface reports the SMT topology indirectly via the maximum
thread id. Each reported CPU in the result of a read-scp-information
is a core representing a number of hardware threads.

To reflect the reduced CPU capacity if two hardware threads run on a
single core the MT utilization counter set is used to normalize the
raw cputime obtained by the CPU timer deltas. This scaled cputime is
reported via the taskstats interface. The normal /proc/stat numbers
are based on the raw cputime and are not affected by the normalization.

Signed-off-by: Martin Schwidefsky

s390/kdump: add support for vector extension

2014-10-09T07:14:16+00:00

With this patch for kdump the s390 vector registers are stored into the
prepared save areas in the old kernel and into the REGSET_VX_LOW and
REGSET_VX_HIGH ELF notes for /proc/vmcore in the new kernel.

The NT_S390_VXRS_LOW note contains the lower halves of the first 16 vector
registers 0-15. The higher halves are stored in the floating point register
ELF note.  The NT_S390_VXRS_HIGH contains the full vector registers 16-31.

The kernel provides a save area for storing vector register in case of
machine checks. A pointer to this save are is stored in the CPU lowcore
at offset 0x11b0. This save area is also used to save the registers for
kdump. In case of a dumped crashed kdump those areas are used to extract
the registers of the production system.

The vector registers for remote CPUs are stored using the "store additional
status at address" SIGP. For the dump CPU the vector registers are stored
with the VSTM instruction.

With this patch also zfcpdump stores the vector registers.

Reviewed-by: Heiko Carstens 
Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky

s390: make various functions static, add declarations to header files

2013-09-07T09:58:03+00:00

Make various functions static, add declarations to header files to
fix a couple of sparse findings.

Signed-off-by: Heiko Carstens

s390/kdump: Add PM notifier for kdump

2013-04-15T11:34:44+00:00

For s390 the page table mapping for the crashkernel memory is removed to
protect the pre-loaded kdump kernel and ramdisk. Because the crashkernel
memory is not included in the page tables for suspend/resume it is not
included in the suspend image. Therefore after resume the resumed system
does no longer contain the pre-loaded kdump kernel and when kdump is
triggered it fails.

This patch adds a PM notifier that creates the page tables before suspend
is done and removes them for resume. This ensures that the kdump kernel
is included in the suspend image.

Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky

s390/crashdump: move fill_cpu_elf_notes() prototype to header file

2012-09-26T13:45:22+00:00

Move fill_cpu_elf_notes() prototype to header file.
This way we get compile errors if e.g. the number of function
parameters get changed.
Otherwise it's possible to change just the definition and everything
else still compiles fine, but the result is broken code.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/kexec: change return value of machine_kexec_prepare

2012-09-26T13:45:14+00:00

Returning -ENOSYS on kexec_load() is a bad idea since user space cannot
tell if the system call is not implmented or if it failed.
Use -EOPNOTSUPP in case somebody tries a kexec_load on a NSS image based
kernel instead.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/kexec: move machine_crash_shutdown() to machine_kexec.c

2012-09-26T13:44:54+00:00

machine_crash_shutdown() was the only function in crash.c.
So move the function and delete one file.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/comments: unify copyright messages and remove file names

2012-07-20T09:15:04+00:00

Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens

s390/kdump: Use real mode for PSW restart and kexec

2012-05-23T15:06:51+00:00

Currently the PSW restart handler and kexec are executed in real
mode with DAT=off. For kexec/kdump the function setup_regs() is
called that uses the per-cpu variable "crash_notes". Because
there are situations when the per-cpu implementation uses vmalloc
memory, calling setup_regs() in real mode can cause a program
check interrupt.

To fix that problem this patch changes the following:

* Ensure that diag308_reset() does not change PSW bits to real mode
* Enable DAT in __do_restart() after we switched to an online CPU
* Enable DAT in __machine_kexec() after we switched to the IPL CPU
* Call setup_regs() before we switch to real mode and call purgatory

Reviewed-by: Martin Schwidefsky 
Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky

s390/kdump: Account /sys/kernel/kexec_crash_size changes in OS info

2012-05-23T15:06:51+00:00

The crashkernel size for kdump can be reduced at runtime with the
sysfs file "/sys/kernel/kexec_crash_size". Currently those changes
do not update the OS info crashkernel information that is used
for stand-alone kdump. With this fix now also the OS info crashkernel
information is updated correctly.

Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky