litmus-rt.git/arch/powerpc/kernel, branch wip-default-clustering

powerpc: remove unused variable

2010-10-06T00:27:54+00:00

Since powerpc uses -Werror on arch powerpc, the build was broken like
this:

  cc1: warnings being treated as errors
  arch/powerpc/kernel/module.c: In function 'module_finalize':
  arch/powerpc/kernel/module.c:66: error: unused variable 'err'

Signed-off-by: Stephen Rothwell 
Signed-off-by: Linus Torvalds

modules: Fix module_bug_list list corruption race

2010-10-05T18:29:27+00:00

With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.

However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling.  That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.

Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.

So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.

Future fixups:
 - move the module list handling code into kernel/module.c where it
   belongs.
 - get rid of 'module_bug_list' and just use the regular list of modules
   (called 'modules' - imagine that) that we already create and maintain
   for other reasons.

Reported-and-tested-by: Thomas Gleixner 
Cc: Rusty Russell 
Cc: Adrian Bunk 
Cc: Andrew Morton 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

powerpc: fix double syscall restarts

2010-09-22T16:33:50+00:00

Make sigreturn zero regs->trap, make do_signal() do the same on all
paths.  As it is, signal interrupting e.g. read() from fd 512 (==
ERESTARTSYS) with another signal getting unblocked when the first
handler finishes will lead to restart one insn earlier than it ought
to.  Same for multiple signals with in-kernel handlers interrupting
that sucker at the same time.  Same for multiple signals of any kind
interrupting that sucker on 64bit...

Signed-off-by: Al Viro 
Acked-by: Paul Mackerras 
Signed-off-by: Linus Torvalds

powerpc: Don't use kernel stack with translation off

2010-08-31T01:35:13+00:00

In f761622e59433130bc33ad086ce219feee9eb961 we changed
early_setup_secondary so it's called using the proper kernel stack
rather than the emergency one.

Unfortunately, this stack pointer can't be used when translation is off
on PHYP as this stack pointer might be outside the RMO.  This results in
the following on all non zero cpus:
  cpu 0x1: Vector: 300 (Data Access) at [c00000001639fd10]
      pc: 000000000001c50c
      lr: 000000000000821c
      sp: c00000001639ff90
     msr: 8000000000001000
     dar: c00000001639ffa0
   dsisr: 42000000
    current = 0xc000000016393540
    paca    = 0xc000000006e00200
      pid   = 0, comm = swapper

The original patch was only tested on bare metal system, so it never
caught this problem.

This changes __secondary_start so that we calculate the new stack
pointer but only start using it after we've called early_setup_secondary.

With this patch, the above problem goes away.

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt

powerpc/perf_event: Reduce latency of calling perf_event_do_pending

2010-08-31T01:35:13+00:00

Commit 0fe1ac48 ("powerpc/perf_event: Fix oops due to
perf_event_do_pending call") moved the call to perf_event_do_pending
in timer_interrupt() down so that it was after the irq_enter() call.
Unfortunately this moved it after the code that checks whether it
is time for the next decrementer clock event.  The result is that
the call to perf_event_do_pending() won't happen until the next
decrementer clock event is due.  This was pointed out by Milton
Miller.

This fixes it by moving the check for whether it's time for the
next decrementer clock event down to the point where we're about
to call the event handler, after we've called perf_event_do_pending.

This has the side effect that on old pre-Core99 Powermacs where we
use the ppc_n_lost_interrupts mechanism to replay interrupts, a
replayed interrupt will incur a little more latency since it will
now do the code from the irq_enter down to the irq_exit, that it
used to skip.  However, these machines are now old and rare enough
that this doesn't matter.  To make it clear that ppc_n_lost_interrupts
is only used on Powermacs, and to speed up the code slightly on
non-Powermac ppc32 machines, the code that tests ppc_n_lost_interrupts
is now conditional on CONFIG_PMAC as well as CONFIG_PPC32.

Signed-off-by: Paul Mackerras 
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt

powerpc/kexec: Adds correct calling convention for kexec purgatory

2010-08-31T01:35:12+00:00

Call kexec purgatory code correctly. We were getting lucky before.
If you examine the powerpc 32bit kexec "purgatory" code you will
see it expects the following:

>From kexec-tools: purgatory/arch/ppc/v2wrap_32.S
-> calling convention:
->   r3 = physical number of this cpu (all cpus)
->   r4 = address of this chunk (master only)

As such, we need to set r3 to the current core, r4 happens to be
unused by purgatory at the moment but we go ahead and set it
here as well

Signed-off-by: Matthew McClintock 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Wire up fanotify_init, fanotify_mark, prlimit64 syscalls

2010-08-24T05:28:28+00:00

Signed-off-by: Andreas Schwab 
Signed-off-by: Benjamin Herrenschmidt

powerpc/pci: Fix checking for child bridges in PCI code.

2010-08-24T05:28:27+00:00

pci_device_to_OF_node() can return null, and list_for_each_entry will
never enter the loop when dev is NULL, so it looks like this test is
a typo.

Reported-by: Julia Lawall 
Signed-off-by: Grant Likely 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Initialise paca->kstack before early_setup_secondary

2010-08-24T05:26:31+00:00

As early setup calls down to slb_initialize(), we must have kstack
initialised before checking "should we add a bolted SLB entry for our kstack?"

Failing to do so means stack access requires an SLB miss exception to refill
an entry dynamically, if the stack isn't accessible via SLB(0) (kernel text
& static data).  It's not always allowable to take such a miss, and
intermittent crashes will result.

Primary CPUs don't have this issue; an SLB entry is not bolted for their
stack anyway (as that lives within SLB(0)).  This patch therefore only
affects the init of secondaries.

Signed-off-by: Matt Evans 
Cc: stable 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix bogus it_blocksize in VIO iommu code

2010-08-24T05:26:31+00:00

When looking at some issues with the virtual ethernet driver I noticed
that TCE allocation was following a very strange pattern:

address 00e9000 length 2048
address 0409000 length 2048 <-----
address 0429000 length 2048
address 0449000 length 2048
address 0469000 length 2048
address 0489000 length 2048
address 04a9000 length 2048
address 04c9000 length 2048
address 04e9000 length 2048
address 4009000 length 2048 <-----
address 4029000 length 2048

Huge unexplained gaps in what should be an empty TCE table. It turns out
it_blocksize, the amount we want to align the next allocation to, was
c0000000fe903b20. Completely bogus.

Initialise it to something reasonable in the VIO IOMMU code, and use kzalloc
everywhere to protect against this when we next add a non compulsary
field to iommu code and forget to initialise it.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt