linux_dsm_epyc7002/arch/x86
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
..
boot x86, setup: un-resequence mode setting for VGA 80x34 and 80x60 modes 2009-04-07 10:59:25 -07:00
configs Merge branches 'x86/apic', 'x86/defconfig', 'x86/memtest', 'x86/mm' and 'linus' into x86/core 2009-02-26 06:31:32 +01:00
crypto crypto: aes-ni - Add support to Intel AES-NI instructions for x86_64 platform 2009-02-18 16:48:06 +08:00
ia32 preadv/pwritev: Add preadv and pwritev system calls. 2009-04-02 19:05:08 -07:00
include/asm Merge branch 'for-rc1/xen/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2009-04-13 15:30:20 -07:00
kernel x86, irq: Remove IRQ_DISABLED check in process context IRQ move 2009-04-14 15:21:13 +02:00
kvm Merge branch 'tracing/core-v2' into tracing-for-linus 2009-04-02 00:49:02 +02:00
lguest Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest-and-virtio 2009-03-30 17:57:39 -07:00
lib x86: memcpy, clean up 2009-03-12 12:21:17 +01:00
math-emu Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2 2009-03-27 17:28:43 +01:00
mm x86: fix wrong section of pat_disable & make it static 2009-04-12 12:34:23 +02:00
oprofile cpumask: x86: convert cpu_sibling_map/cpu_core_map to cpumask_var_t 2009-03-13 14:49:50 +10:30
pci x86, PAT: Remove duplicate memtype reserve in pci mmap 2009-04-03 14:43:29 -07:00
power x86: disable stack-protector for __restore_processor_state() 2009-04-03 19:48:41 +02:00
vdso x86, mm: rename TASK_SIZE64 => TASK_SIZE_MAX 2009-02-21 00:09:44 +01:00
video
xen Merge branch 'for-rc1/xen/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2009-04-13 15:30:20 -07:00
Kconfig x86, intel-iommu: fix X2APIC && !ACPI build failure 2009-04-07 08:22:46 +02:00
Kconfig.cpu x86/centaur: merge 32 & 64 bit version 2009-03-14 16:27:29 +01:00
Kconfig.debug generic debug pagealloc: build fix 2009-04-02 19:04:48 -07:00
Makefile x86: use targets in the boot Makefile instead of CLEAN_FILES 2009-03-12 13:43:14 -07:00
Makefile_32.cpu