litmus2008.git/arch/s390/kernel, branch master

[S390] Make sure the restore psw masks are initialized.

2007-12-04T15:09:58+00:00

In case of TRACE_IRQFLAGS the restore psw masks will not be
initialized if noexec is turned on. This will lead to an
immediate system crash.

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

[S390] Fix compile error on 31bit without preemption

2007-12-04T15:09:58+00:00

Commit b8e7a54cd06b0b0174029ef3a7f5a1415a2c28f2 introduced a compile
error if CONFIG_PREEMPT is not set:

arch/s390/kernel/built-in.o: In function `cleanup_io_leave_insn':
/space/kvm/arch/s390/kernel/entry.S:(.text+0xbfce): undefined reference to `preempt_schedule_irq'

This patch hides preempt_schedule_irq if CONFIG_PREEMPT is not set.

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

[S390] Add missing die_notifier() call to die().

2007-11-20T10:13:48+00:00

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

[S390] Fix memory detection.

2007-11-20T10:13:48+00:00

Before we're getting short on memory detection fixes here is the next
one: if neither sclp nor diag260 report the storage size the detection
loop will return immediately without detecting anything. Fix this by
breaking the detection loop only if the memory end is known.

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

[S390] Dont overwrite lowcores on smp_send_stop().

2007-11-20T10:13:47+00:00

Don't perform a sigp store-status-at-address on smp_send_stop().
It will overwrite the lowcores of other cpus and destroys valueable
debug informations.

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

[S390] Fix kernel preemption.

2007-11-20T10:13:46+00:00

When returning from IRQ handling and TIF_NEED_RESCHED is set we must
call preempt_schedule_irq() instead of schedule().
Otherwise the BKL might be unlocked in schedule() and therfore
everything that relies on the BKL is broken.

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

[S390] Fix irq tracing and lockdep_sys_exit calls.

2007-11-20T10:13:45+00:00

Current support for TRACE_IRQFLAGS and lockdep_sys_exit is broken.
IRQ flag tracing is broken for program checks. Even worse is that
the newly introduced calls to lockdep_sys_exit are in the critical
section code which is not supposed to call any C functions. In
addition the checks if locks are still held are also done when
returning to kernel code which is broken as well.
Fix all this by disabling interrupts and machine checks at the
exit paths and then do the appropriate checks and calls.

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

[S390] magic sysrq: check for in_atomic before doing an console_unblank

2007-11-20T10:13:44+00:00

When doing an magic sysrq reboot on s390 the following bug message
appears:

SysRq : Resetting
BUG: sleeping function called from invalid context at include/asm/semaphore.h:61

in_atomic():1, irqs_disabled():0
07000000004002a8 000000000fe6bc48 0000000000000002 0000000000000000
       000000000fe6bce8 000000000fe6bc60 000000000fe6bc60 000000000012a79a
       0000000000000000 07000000004002a8 0000000000000006 0000000000000000
       0000000000000000 000000000fe6bc48 000000000000000d 000000000fe6bcb8
       00000000004000c8 0000000000103234 000000000fe6bc48 000000000fe6bc90
Call Trace:
(¬<00000000001031b2>| show_trace+0x12e/0x148)
 ¬<000000000011ffca>| __might_sleep+0x10a/0x118
 ¬<0000000000129fba>| acquire_console_sem+0x92/0xf4
 ¬<000000000012a2ca>| console_unblank+0xc2/0xc8
 ¬<0000000000107bb4>| machine_restart+0x54/0x6c
 ¬<000000000028e806>| sysrq_handle_reboot+0x26/0x30
 ¬<000000000028e52a>| __handle_sysrq+0xa6/0x180
 ¬<0000000000140134>| run_workqueue+0xcc/0x18c
 ¬<000000000014029a>| worker_thread+0xa6/0x108
 ¬<00000000001458e4>| kthread+0x64/0x9c
 ¬<0000000000106f0e>| kernel_thread_starter+0x6/0xc
 ¬<0000000000106f08>| kernel_thread_starter+0x0/0xc

The only reason for doing a console_unblank on s390 is to flush the
log buffer. We have to check for in_atomic before doing a
console_unblank as the console is otherwise filled with an unrelated
bug message.

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

sched: restore deterministic CPU accounting on powerpc

2007-11-09T21:39:38+00:00

Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the
deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been
broken on powerpc, because we end up counting user time twice: once in
timer_interrupt() and once in update_process_times().

This fixes the problem by pulling the code in update_process_times
that updates utime and stime into a separate function called
account_process_tick.  If CONFIG_VIRT_CPU_ACCOUNTING is not defined,
there is a version of account_process_tick in kernel/timer.c that
simply accounts a whole tick to either utime or stime as before.  If
CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to
implement account_process_tick.

This also lets us simplify the s390 code a bit; it means that the s390
timer interrupt can now call update_process_times even when
CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a
suitable account_process_tick().

account_process_tick() now takes the task_struct * as an argument.
Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING.

Signed-off-by: Paul Mackerras 
Signed-off-by: Ingo Molnar

[S390] tod clock: announce clocksource as perfect

2007-11-05T10:10:18+00:00

The Time of Day clock is the standard time source for s390. It is
- monotonic
- allows very fast reading
- architecture guarantees at least microsecond stepping
- available as part of the architecture

We should announce the rate of tod as 400 to be in sync with the
description found in clocksource.h:
"400-499:Perfect The ideal clocksource. A must-use where available."

This change will prefer tod over less reliable clock sources.

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