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authorPallipadi, Venkatesh <venkatesh.pallipadi@intel.com>2009-04-13 15:20:58 -0700
committerIngo Molnar <mingo@elte.hu>2009-04-14 15:21:13 +0200
commit6ec3cfeca04622e3d80c9270191cd7f5f88214af (patch)
treeba9d66ec365e59842fe97d72855c6065763dfe98 /kernel
parentb21597d0268983f8f9e8b563494f75490403e948 (diff)
downloadlinux-6ec3cfeca04622e3d80c9270191cd7f5f88214af.tar.bz2
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 932775a4ab622e3c99bd59f14cc 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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/irq/manage.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 7e2e7dd4cd2f..2734eca59243 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -109,10 +109,9 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
spin_lock_irqsave(&desc->lock, flags);
#ifdef CONFIG_GENERIC_PENDING_IRQ
- if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
- cpumask_copy(desc->affinity, cpumask);
+ if (desc->status & IRQ_MOVE_PCNTXT)
desc->chip->set_affinity(irq, cpumask);
- } else {
+ else {
desc->status |= IRQ_MOVE_PENDING;
cpumask_copy(desc->pending_mask, cpumask);
}