linux-stable.git/arch/powerpc/include/asm/rtas.h, branch linux-3.3.y

powerpc: Punch a hole in /dev/mem for librtas

2011-12-08T03:22:52+00:00

With CONFIG_STRICT_DEVMEM=y, user space cannot read any part of /dev/mem.
Since this breaks librtas, punch a hole in /dev/mem to allow access to the
rmo_buffer that librtas needs.

Anton Blanchard reported the problem and helped with the fix.

A quick test for this patch:

       # cat /proc/rtas/rmo_buffer
       000000000f190000 10000

       # python -c "print 0x000000000f190000 / 0x10000"
       3865

       # dd if=/dev/mem of=/tmp/foo count=1 bs=64k skip=3865
       1+0 records in
       1+0 records out
       65536 bytes (66 kB) copied, 0.000205235 s, 319 MB/s

       # dd if=/dev/mem of=/tmp/foo
       dd: reading `/dev/mem': Operation not permitted
       0+0 records in
       0+0 records out
       0 bytes (0 B) copied, 0.00022519 s, 0.0 kB/s

Signed-off-by: Sukadev Bhattiprolu 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Cancel RTAS event scan before firmware flash

2011-11-25T03:11:29+00:00

The RTAS firmware flash update is conducted using an RTAS call that is
serialized by lock_rtas() which uses spin_lock. While the flash is in
progress, rtasd performs scan for any RTAS events that are generated by
the system. rtasd keeps scanning for the RTAS events generated on the
machine. This is performed via workqueue mechanism. The rtas_event_scan()
also uses an RTAS call to scan the events, eventually trying to acquire
the spin_lock before issuing the request.

The flash update takes a while to complete and during this time, any other
RTAS call has to wait. In this case, rtas_event_scan() waits for a long time
on the spin_lock resulting in a soft lockup.

Fix: Just before the flash update is performed, the queued rtas_event_scan()
work item is cancelled from the work queue so that there is no other RTAS
call issued while the flash is in progress. After the flash completes, the
system reboots and the rtas_event_scan() is rescheduled.

Signed-off-by: Suzuki Poulose 
Signed-off-by: Ravi Nittala 
Reported-by: Divya Vikas 
Signed-off-by: Benjamin Herrenschmidt

powerpc/nvram: Add compression to fit more oops output into NVRAM

2011-09-19T23:19:46+00:00

Capture more than twice as much text from the printk buffer, and
compress it to fit it in the lnx,oops-log NVRAM partition.  You
can view the compressed text using the new (as of July 20) --unzip
option of the nvram command in the powerpc-utils package.

[BenH: Added select of ZLIB_DEFLATE]

Signed-off-by: Jim Keniston 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Add RTAS event log v6 definition

2011-05-06T03:18:59+00:00

This patch adds definitions of non-IBM specific v6 extended log
definitions to rtas.h.

Signed-off-by: Tseng-Hui (Frank) Lin 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Export rtas_ibm_suspend_me()

2010-10-13T05:19:02+00:00

Export the rtas_ibm_suspend_me() routine.  This is needed to perform
partition migration in the kernel.

Signed-off-by: Nathan Fontenot 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Rename RAS_VECTOR_OFFSET to RTAS_VECTOR_EXTERNAL_INTERRUPT and move to rtas.h

2010-07-09T01:28:31+00:00

The RAS code has a #define, RAS_VECTOR_OFFSET, that's used in the
check-exception RTAS call for the vector offset of the exception.

We'll be using this same vector offset for the upcoming IO Event interrupts
code (0x500) so let's move it to include/asm/rtas.h and call it
RTAS_VECTOR_EXTERNAL_INTERRUPT.

Signed-off-by: Mark Nelson 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pseries: Migration code reorganization / hibernation prep

2010-07-09T01:26:17+00:00

Partition hibernation will use some of the same code as is
currently used for Live Partition Migration. This function
further abstracts this code such that code outside of rtas.c
can utilize it. It also changes the error field in the suspend
me data structure to be an atomic type, since it is set and
checked on different cpus without any barriers or locking.

Signed-off-by: Brian King 
Signed-off-by: Benjamin Herrenschmidt

locking: Convert raw_spinlock to arch_spinlock

2009-12-14T22:55:32+00:00

The raw_spin* namespace was taken by lockdep for the architecture
specific implementations. raw_spin_* would be the ideal name space for
the spinlocks which are not converted to sleeping locks in preempt-rt.

Linus suggested to convert the raw_ to arch_ locks and cleanup the
name space instead of using an artifical name like core_spin,
atomic_spin or whatever

No functional change.

Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra 
Acked-by: David S. Miller 
Acked-by: Ingo Molnar 
Cc: linux-arch@vger.kernel.org

powerpc: Use one common impl. of RTAS timebase sync and use raw spinlock

2009-06-26T06:55:25+00:00

Several platforms use their own copy of what is essentially the same code,
using RTAS to synchronize the timebases when bringing up new CPUs. This
moves it all into a single common implementation and additionally
turns the spinlock into a raw spinlock since the former can rely on
the timebase not being frozen when spinlock debugging is enabled, and finally
masks interrupts while the timebase is disabled.

Signed-off-by: Benjamin Herrenschmidt

powerpc/rtas: Turn rtas lock into a raw spinlock

2009-06-26T04:37:27+00:00

RTAS currently uses a normal spinlock. However it can be called from
contexts where this is not necessarily a good idea. For example, it
can be called while syncing timebases, with the core timebase being
frozen. Unfortunately, that will deadlock in case of lock contention
when spinlock debugging is enabled as the spin lock debugging code
will try to use __delay() which ... relies on the timebase being
enabled.

Also RTAS can be used in some low level IRQ handling code path so it
may as well be a raw spinlock for -rt sake.

Signed-off-by: Benjamin Herrenschmidt