linux_dsm_epyc7002/arch
Thomas Gleixner 01f8fa4f01 genirq: Allow forcing cpu affinity of interrupts
The current implementation of irq_set_affinity() refuses rightfully to
route an interrupt to an offline cpu.

But there is a special case, where this is actually desired. Some of
the ARM SoCs have per cpu timers which require setting the affinity
during cpu startup where the cpu is not yet in the online mask.

If we can't do that, then the local timer interrupt for the about to
become online cpu is routed to some random online cpu.

The developers of the affected machines tried to work around that
issue, but that results in a massive mess in that timer code.

We have a yet unused argument in the set_affinity callbacks of the irq
chips, which I added back then for a similar reason. It was never
required so it got not used. But I'm happy that I never removed it.

That allows us to implement a sane handling of the above scenario. So
the affected SoC drivers can add the required force handling to their
interrupt chip, switch the timer code to irq_force_affinity() and
things just work.

This does not affect any existing user of irq_set_affinity().

Tagged for stable to allow a simple fix of the affected SoC clock
event drivers.

Reported-and-tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Tomasz Figa <t.figa@samsung.com>,
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>,
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: linux-arm-kernel@lists.infradead.org,
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20140416143315.717251504@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-04-17 23:36:27 +02:00
..
alpha Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
arc ARC changes for 3.15 2014-04-07 17:51:34 -07:00
arm Update bcm_defconfig with new pinctrl CONFIG 2014-04-14 09:39:33 +02:00
arm64 - Documentation clarification on CPU topology and booting requirements 2014-04-08 12:06:03 -07:00
avr32 Char/Misc driver patches for 3.15-rc1 2014-04-01 16:13:21 -07:00
blackfin blackfin updates for Linux 3.15 2014-04-12 17:26:45 -07:00
c6x Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-03-31 10:59:39 -07:00
cris Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
frv PCI changes for the v3.15 merge window: 2014-04-01 15:14:04 -07:00
hexagon Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
ia64 Small workaround for a rare, but annoying, erratum 2014-04-16 11:22:45 -07:00
m32r Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
m68k Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
metag Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
microblaze Microblaze patches for 3.15-rc1 2014-04-11 11:53:45 -07:00
mips genirq: Allow forcing cpu affinity of interrupts 2014-04-17 23:36:27 +02:00
mn10300 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
openrisc Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
parisc Merge branch 'parisc-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2014-04-17 13:21:35 -07:00
powerpc powerpc: Don't try to set LPCR unless we're in hypervisor mode 2014-04-12 17:58:48 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-04-16 11:28:25 -07:00
score score: remove unused CPU_SCORE7 Kconfig parameter 2014-04-03 16:20:52 -07:00
sh Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
sparc Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
tile Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
um Merge git://git.infradead.org/users/eparis/audit 2014-04-12 12:38:53 -07:00
unicore32 Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP 2014-04-07 16:36:11 -07:00
x86 Xen regression and bug fixes for 3.15-rc1. 2014-04-17 10:54:07 -07:00
xtensa Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
.gitignore
Kconfig uprobes: Kconfig dependency fix 2014-03-18 16:39:33 -04:00