linux-stable.git/arch/s390/kernel/entry64.S, branch linux-3.6.y

s390/vtimer: rework virtual timer interface

2012-07-20T09:15:08+00:00

The current virtual timer interface is inherently per-cpu and hard to
use. The sole user of the interface is appldata which uses it to execute
a function after a specific amount of cputime has been used over all cpus.

Rework the virtual timer interface to hook into the cputime accounting.
This makes the interface independent from the CPU timer interrupts, and
makes the virtual timers global as opposed to per-cpu.
Overall the code is greatly simplified. The downside is that the accuracy
is not as good as the original implementation, but it is still good enough
for appldata.

Reviewed-by: Jan Glauber 
Reviewed-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/smp: make absolute lowcore / cpu restart parameter accesses more robust

2012-06-14T07:09:02+00:00

Setting the cpu restart parameters is done in three different fashions:
- directly setting the four parameters individually
- copying the four parameters with memcpy (using 4 * sizeof(long))
- copying the four parameters using a private structure

In addition code in entry*.S relies on a certain order of the restart
members of struct _lowcore.

Make all of this more robust to future changes by adding a
mem_absolute_assign(dest, val) define, which assigns val to dest
using absolute addressing mode. Also the load multiple instructions
in entry*.S have been split into separate load instruction so the
order of the struct _lowcore members doesn't matter anymore.

In addition move the prototypes of memcpy_real/absolute from uaccess.h
to processor.h. These memcpy* variants are not related to uaccess at all.
string.h doesn't seem to match as well, so lets use processor.h.

Also replace the eight byte array in struct _lowcore which represents a
misaliged u64 with a u64. The compiler will always create code that
handles the misaligned u64 correctly.

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

s390/sigp: use sigp order code defines in assembly code

2012-06-05T11:23:36+00:00

Use sigp order code defines in assembly code as well.
With this change all places that use sigp constants should
have been converted to use self describing defines instead
of directly using constants.

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

s390/kvm: get rid of duplicate instruction

2012-06-05T11:23:35+00:00

After
commit 5e8010cb50d3de7202641c0088c211f7c9593ebc
    s390: replace TIF_SIE with PF_VCPU
there is no need to load the thread info before sie_loop where
it is also loaded.
Get rid of this duplicate instruction.

Signed-off-by: Christian Borntraeger 
Signed-off-by: Martin Schwidefsky

s390: fix race on TIF_MCCK_PENDING

2012-05-16T12:42:46+00:00

There is a small race window in the __switch_to code in regard to
the transfer of the TIF_MCCK_PENDING bit from the previous to the
next task. The bit is transferred before the task struct pointer
and the thread-info pointer for the next task has been stored to
lowcore. If a machine check sets the TIF_MCCK_PENDING bit between
the transfer code and the store of current/thread_info the bit
is still set for the previous task. And if the previous task has
terminated it can get lost. The effect is that a pending CRW is
not retrieved until the next machine checks sets TIF_MCCK_PENDING.
To fix this reorder __switch_to to first store the task struct
and thread-info pointer and then do the transfer of the bit.

Signed-off-by: Martin Schwidefsky

s390/time: simply Kconfig dependency

2012-05-16T12:42:44+00:00

Use HAVE_MARCH_Z9_109_FEATURES to figure out if stckf is available
at compile time.

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

s390/entry64: avoid SPP code duplication

2012-05-16T12:42:43+00:00

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

s390/time: always use stckf instead of stck if available

2012-05-16T12:42:41+00:00

The store clock fast instruction saves a couple of instructions compared
to the store clock instruction. Always use stckf instead of stck if it
is available.

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

s390: replace TIF_SIE with PF_VCPU

2012-05-16T12:42:39+00:00

Replace the check for TIF_SIE in the fault handler by a check for PF_VCPU.
With the last user of TIF_SIE gone we can now remove the bit.

Signed-off-by: Martin Schwidefsky