linux-toradex.git/arch/powerpc/kernel, branch v2.6.20.10

POWERPC: Fix performance monitor exception

2007-03-09T18:50:25+00:00

To the issue: some point during 2.6.20 development, Paul Mackerras
introduced the "lazy IRQ  disabling" patch (very cool work,  BTW).
In that patch, the performance monitor unit exception was marked as
"maskable", in the sense that if interrupts were soft-disabled, that
exception could be ignored.  This broke my PowerPC profiling code.
The symptom that I see is that a varying number of interrupts
(from 0 to $n$, typically closer to 0) get delivered, when, in
reality, it should always be very close to $n$.

The issue stems from the way masking is being done.   Masking in
this fashion seems to  work well with the decrementer and external
interrupts, because they are raised again until "really"  handled.
For the PMU, however, this does not apply (at least on my Xserver
machine with a 970FX processor).  If the PMU exception is not handled,
it will _not_ be re-raised (at least on my machine).  The documentation
states that the PMXE bit in MMCR0 is set to 0 when the PMU exception
is raised.  However, software must re-set the bit to re-enable PMU
exceptions.  If the exception is ignored (as currently) not only is
that interrupt lost, but because software does not re-set PMXE, the
PMU registers are "frozen" forever.

[This patch means that performance monitor exceptions are taken and
handled even if irqs are off, as long as some other interrupt hasn't
come along and caused interrupts to be hard-disabled.  In this sense
the PMU exception becomes like an NMI.  The oprofile code for most
powerpc processors does nothing that is unsafe in an NMI context, but
the Cell oprofile code does a spin_lock_irqsave.  However, that turns
out to be OK because Cell doesn't actually use the performance
monitor exception; performance monitor interrupts come in as a
regular interrupt on Cell, so will be disabled when irqs are off.
 -- paulus.]

From: Livio Soares 
Signed-off-by: Paul Mackerras 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

2007-01-28T20:45:22+00:00

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  [POWERPC] Fix sys_pciconfig_iobase bus matching
  [POWERPC] PS3: add not complete comment to kconfig
  [POWERPC] ps3_free_io_irq: Fix inverted error check
  [POWERPC] PS3: Fix uniprocessor kernel build

[POWERPC] Fix sys_pciconfig_iobase bus matching

2007-01-27T22:57:09+00:00

A stupid bug has been plaguing the sys_pciconfig_iobase on ppc64. It wasn't
noticed until recently as it seems to not affect G5s but it's been causing
problems running X servers on some other machines recently. The bus number
matching was bogus.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Paul Mackerras

[PATCH] powerpc vDSO: use VM_ALWAYSDUMP

2007-01-26T21:50:58+00:00

This patch fixes core dumps to include the vDSO vma, which is left out now.

Signed-off-by: Roland McGrath 
Cc: Ingo Molnar 
Cc: Paul Mackerras 
Acked-by: Benjamin Herrenschmidt 
Cc: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[POWERPC] Remove bogus sanity check in pci -> OF node code

2007-01-22T10:27:35+00:00

The new implementation of pci_device_to_OF_node() on ppc32 has a bogus
sanity check in it that can cause oopses at boot when no device node is
present, and might hit correct cases with older/weird apple device-trees
where they have the type "vci" for the chaos bridge.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Paul Mackerras

[PATCH] Change cpu_up and co from devinit to cpuinit

2007-01-12T02:18:20+00:00

Compiling the kernel with CONFIG_HOTPLUG = y and CONFIG_HOTPLUG_CPU = n
with CONFIG_RELOCATABLE = y generates the following modpost warnings

WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141b7d) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141b9c) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.text:__cpu_up
from .text between '_cpu_up' (at offset 0xc0141bd8) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141c05) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141c26) and 'cpu_up'
WARNING: vmlinux - Section mismatch: reference to .init.data: from
.text between '_cpu_up' (at offset 0xc0141c37) and 'cpu_up'

This is because cpu_up, _cpu_up and __cpu_up (in some architectures) are
defined as __devinit
AND
__cpu_up calls some __cpuinit functions.

Since __cpuinit would map to __init with this kind of a configuration,
we get a .text refering .init.data warning.

This patch solves the problem by converting all of __cpu_up, _cpu_up
and cpu_up from __devinit to __cpuinit. The approach is justified since
the callers of cpu_up are either dependent on CONFIG_HOTPLUG_CPU or
are of __init type.

Thus when CONFIG_HOTPLUG_CPU=y, all these cpu up functions would land up
in .text section, and when CONFIG_HOTPLUG_CPU=n, all these functions would
land up in .init section.

Tested on a i386 SMP machine running linux-2.6.20-rc3-mm1.

Signed-off-by: Gautham R Shenoy 
Cc: Vivek Goyal 
Cc: Mikael Starvik 
Cc: Ralf Baechle 
Cc: Kyle McMartin 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: "David S. Miller" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[POWERPC] Fix manual assembly WARN_ON() in enter_rtas().

2007-01-09T06:03:02+00:00

When we switched over to the generic BUG mechanism we forgot to change
the assembly code which open-codes a WARN_ON() in enter_rtas(), so the
bug table got corrupted.

This patch provides an EMIT_BUG_ENTRY macro for use in assembly code,
and uses it in entry_64.S. Tested with CONFIG_DEBUG_BUGVERBOSE on ppc64
but not without -- I tried to turn it off but it wouldn't go away; I
suspect Aunt Tillie probably needed it.

This version gets __FILE__ and __LINE__ right in the assembly version --
rather than saying include/asm-powerpc/bug.h line 21 every time which is
a little suboptimal.

Signed-off-by: David Woodhouse 
Signed-off-by: Paul Mackerras

[POWERPC] Fix register save area alignment for swapcontext syscall

2006-12-20T05:37:49+00:00

For 32-bit processes, the getcontext side of the swapcontext system
call (i.e. the saving of the context when the first argument is
non-NULL) has to set the ctx->uc_mcontext.uc_regs pointer to the place
where it saves the registers.  Which it does, but it doesn't ensure
that the pointer is 16-byte aligned.  16-byte alignment is needed
because the Altivec/VMX registers are saved in there, and they need to
be on a 16-byte boundary.

This fixes it by ensuring the appropriate alignment of the pointer.
This issue was pointed out by Jakub Jelinek.

Signed-off-by: Paul Mackerras

[POWERPC] Fix PCI device channel state initialization