aha/arch
Pallipadi, Venkatesh 6ec3cfeca0 x86, irq: Remove IRQ_DISABLED check in process context IRQ move
As discussed in the thread here:

  http://marc.info/?l=linux-kernel&m=123964468521142&w=2

Eric W. Biederman observed:

> It looks like some additional bugs have slipped in since last I looked.
>
> set_irq_affinity does this:
> ifdef CONFIG_GENERIC_PENDING_IRQ
>        if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
>                cpumask_copy(desc->affinity, cpumask);
>                desc->chip->set_affinity(irq, cpumask);
>        } else {
>                desc->status |= IRQ_MOVE_PENDING;
>                cpumask_copy(desc->pending_mask, cpumask);
>        }
> #else
>
> That IRQ_DISABLED case is a software state and as such it has nothing to
> do with how safe it is to move an irq in process context.

[...]

>
> The only reason we migrate MSIs in interrupt context today is that there
> wasn't infrastructure for support migration both in interrupt context
> and outside of it.

Yes. The idea here was to force the MSI migration to happen in process
context. One of the patches in the series did

        disable_irq(dev->irq);
        irq_set_affinity(dev->irq, cpumask_of(dev->cpu));
        enable_irq(dev->irq);

with the above patch adding irq/manage code check for interrupt disabled
and moving the interrupt in process context.

IIRC, there was no IRQ_MOVE_PCNTXT when we were developing this HPET
code and we ended up having this ugly hack. IRQ_MOVE_PCNTXT was there
when we eventually submitted the patch upstream. But, looks like I did a
blind rebasing instead of using IRQ_MOVE_PCNTXT in hpet MSI code.

Below patch fixes this. i.e., revert commit 932775a4ab
and add PCNTXT to HPET MSI setup. Also removes copying of desc->affinity
in generic code as set_affinity routines are doing it internally.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Li Shaohua" <shaohua.li@intel.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: "lcm@us.ibm.com" <lcm@us.ibm.com>
Cc: suresh.b.siddha@intel.com
LKML-Reference: <20090413222058.GB8211@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14 15:21:13 +02:00
..
alpha Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
arm Replace all DMA_nBIT_MASK macro with DMA_BIT_MASK(n) 2009-04-13 15:04:33 -07:00
avr32 dma-mapping: replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32) 2009-04-07 08:31:11 -07:00
blackfin tty: Blackin CTS/RTS 2009-04-07 08:44:05 -07:00
cris tty: Use the generic RS485 ioctl on CRIS 2009-04-07 08:44:05 -07:00
frv FRV: Move to arch/frv/include/asm/ 2009-04-10 01:48:06 +01:00
h8300 Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
ia64 Replace all DMA_nBIT_MASK macro with DMA_BIT_MASK(n) 2009-04-13 15:04:33 -07:00
m32r Simplify copy_thread() 2009-04-02 19:04:51 -07:00
m68k Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
m68knommu Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2009-04-03 09:44:58 -07:00
microblaze microblaze_v8: Makefiles for Microblaze cpu 2009-03-27 14:25:51 +01:00
mips Merge branch 'next' into for-linus 2009-04-08 00:00:33 -07:00
mn10300 Separate out the proc- and unit-specific header directories from the general 2009-04-10 14:33:48 +01:00
parisc Merge git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6 2009-04-03 09:52:04 -07:00
powerpc Merge branch 'i2c-for-2630-v2' of git://aeryn.fluff.org.uk/bjdooks/linux 2009-04-07 08:45:12 -07:00
s390 mutex: have non-spinning mutexes on s390 by default 2009-04-09 19:28:24 +02:00
sh Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6 2009-04-05 11:15:54 -07:00
sparc sparc: Hook up sys_preadv and sys_pwritev 2009-04-08 03:55:30 -07:00
um Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
x86 x86, irq: Remove IRQ_DISABLED check in process context IRQ move 2009-04-14 15:21:13 +02:00
xtensa Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
.gitignore
Kconfig mutex: have non-spinning mutexes on s390 by default 2009-04-09 19:28:24 +02:00