linux/kernel/irq
Thomas Gleixner 62a08ae2a5 genirq: x86: Ensure that dynamic irq allocation does not conflict
On x86 the allocation of irq descriptors may allocate interrupts which
are in the range of the GSI interrupts. That's wrong as those
interrupts are hardwired and we don't have the irq domain translation
like PPC. So one of these interrupts can be hooked up later to one of
the devices which are hard wired to it and the io_apic init code for
that particular interrupt line happily reuses that descriptor with a
completely different configuration so hell breaks lose.

Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs,
except for a few usage sites which have not yet blown up in our face
for whatever reason. But for drivers which need an irq range, like the
GPIO drivers, we have no limit in place and we don't want to expose
such a detail to a driver.

To cure this introduce a function which an architecture can implement
to impose a lower bound on the dynamic interrupt allocations.

Implement it for x86 and set the lower bound to nr_gsi_irqs, which is
the end of the hardwired interrupt space, so all dynamic allocations
happen above.

That not only allows the GPIO driver to work sanely, it also protects
the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and
htirq code. They need to be cleaned up as well, but that's a separate
issue.

Reported-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Krogerus Heikki <heikki.krogerus@intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-04-28 12:20:00 +02:00
..
Kconfig genirq: Generic irq chip requires IRQ_DOMAIN 2014-02-05 10:17:32 +01:00
Makefile irq: add irq_domain translation infrastructure 2011-07-28 01:32:04 -06:00
autoprobe.c genirq: Handle pending irqs in irq_startup() 2012-02-15 11:56:59 +01:00
chip.c genirq: Add a new IRQCHIP_EOI_THREADED flag 2014-03-14 13:43:33 +01:00
debug.h irq: hide debug macros so they don't collide with others. 2012-04-23 12:30:03 -04:00
devres.c genirq: Add devm_request_any_context_irq() 2014-02-09 15:27:21 +01:00
dummychip.c genirq: Export dummy_irq_chip 2012-08-21 16:14:23 +02:00
generic-chip.c Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-07-13 15:37:30 -07:00
handle.c genirq: Export symbol no_action() 2014-03-22 11:33:09 +01:00
internals.h genirq: Add a new IRQCHIP_EOI_THREADED flag 2014-03-14 13:43:33 +01:00
irqdesc.c genirq: x86: Ensure that dynamic irq allocation does not conflict 2014-04-28 12:20:00 +02:00
irqdomain.c genirq: Include missing header file in irqdomain.c 2014-02-27 13:29:35 +01:00
manage.c genirq: Allow forcing cpu affinity of interrupts 2014-04-17 23:36:27 +02:00
migration.c genirq: Introduce irq_do_set_affinity() to reduce duplicated code 2012-05-24 22:36:40 +02:00
pm.c irq: Enable all irqs unconditionally in irq_resume 2013-11-25 22:20:02 +01:00
proc.c genirq: procfs: Make smp_affinity values go+r 2014-03-19 12:34:29 +01:00
resend.c genirq: Provide means to retrigger parent 2012-11-01 12:11:31 +01:00
settings.h genirq: Prevent spurious detection for unconditionally polled interrupts 2013-11-13 16:03:02 +01:00
spurious.c genirq: Prevent spurious detection for unconditionally polled interrupts 2013-11-13 16:03:02 +01:00