linux-stable.git/arch/s390/kernel/entry.S, branch linux-3.7.y

s390: convert to generic kernel_execve()

2012-10-01T03:03:04+00:00

same situation as with alpha and arm - only massage needed

Signed-off-by: Al Viro

s390: fold kernel_thread_helper() into ret_from_fork()

2012-10-01T03:03:03+00:00

... and don't bother with syscall return path in case of kernel
threads.

Signed-off-by: Al Viro

s390: fold execve_tail() into start_thread(), convert to generic sys_execve()

2012-10-01T03:03:02+00:00

Signed-off-by: Al Viro

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: 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] rework idle code

2012-03-11T15:59:28+00:00

Whenever the cpu loads an enabled wait PSW it will appear as idle to the
underlying host system. The code in default_idle calls vtime_stop_cpu
which does the necessary voodoo to get the cpu time accounting right.
The udelay code just loads an enabled wait PSW. To correct this rework
the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts
to entry[64].S, vtime_stop_cpu can now be called from anywhere and
vtime_start_cpu is gone. The correction of the cpu time during wakeup
from an enabled wait PSW is done with a critical section in entry[64].S.
As vtime_start_cpu is gone, s390_idle_check can be removed as well.

Signed-off-by: Martin Schwidefsky

[S390] rework smp code

2012-03-11T15:59:28+00:00

Define struct pcpu and merge some of the NR_CPUS arrays into it, including
__cpu_logical_map, current_set and smp_cpu_state. Split smp related
functions to those operating on physical cpus and the functions operating
on a logical cpu number. Make the functions for physical cpus use a
pointer to a struct pcpu. This hides the knowledge about cpu addresses in
smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header.

The PSW restart mechanism is used to start secondary cpus, calling a
function on an online cpu, calling a function on the ipl cpu, and for
the nmi signal. Replace the different assembler functions with a
single function restart_int_handler. The new entry point calls a function
whose pointer is stored in the lowcore of the target cpu and it can wait
for the source cpu to stop. This covers all existing use cases.

Overall the code is now simpler and there are ~380 lines less code.

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