linux-toradex.git/kernel/irq/handle.c, branch v4.9.97

genirq: Add untracked irq handler

2016-06-18T08:00:55+00:00

This adds a software irq handler for controllers that multiplex
interrupts from multiple devices, but don't know which device generated
the interrupt. For these devices, the irq handler that demuxes must
check every action for every software irq using the same h/w irq in order
to find out which device generated the interrupt. This will inevitably
trigger spurious interrupt detection if we are noting the irq.

The new irq handler does not track the handling for spurious interrupt
detection. An irq that uses this also won't get stats tracked since it
didn't generate the interrupt, nor added to randomness since they are
not random.

Signed-off-by: Keith Busch 
Cc: Bjorn Helgaas 
Cc: linux-pci@vger.kernel.org
Cc: Jon Derrick 
Link: http://lkml.kernel.org/r/1466200821-29159-1-git-send-email-keith.busch@intel.com
Signed-off-by: Thomas Gleixner

genirq: Use a common macro to go through the actions list

2016-02-14T23:07:34+00:00

The irq code browses the list of actions differently to inspect the element
one by one. Even if it is not a problem, for the sake of consistent code,
provide a macro similar to for_each_irq_desc in order to have the same loop to
go through the actions list and use it in the code.

[ tglx: Renamed the macro ]

Signed-off-by: Daniel Lezcano 
Link: http://lkml.kernel.org/r/1452765253-31148-1-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Thomas Gleixner

genirq: Validate action before dereferencing it in handle_irq_event_percpu()

2016-01-14T19:09:49+00:00

commit 71f64340fc0e changed the handling of irq_desc->action from

CPU 0                   CPU 1
free_irq()              lock(desc)
  lock(desc)            handle_edge_irq()
                        if (desc->action) {
                          handle_irq_event()
                            action = desc->action
                            unlock(desc)
  desc->action = NULL       handle_irq_event_percpu(desc, action)
                              action->xxx
to

CPU 0                   CPU 1
free_irq()              lock(desc)
  lock(desc)            handle_edge_irq()
                        if (desc->action) {
                          handle_irq_event()
                            unlock(desc)
  desc->action = NULL       handle_irq_event_percpu(desc, action)
                              action = desc->action
                              action->xxx

So if free_irq manages to set the action to NULL between the unlock and before
the readout, we happily dereference a null pointer.

We could simply revert 71f64340fc0e, but we want to preserve the better code
generation. A simple solution is to change the action loop from a do {} while
to a while {} loop.

This is safe because we either see a valid desc->action or NULL. If the action
is about to be removed it is still valid as free_irq() is blocked on
synchronize_irq().

CPU 0                   CPU 1
free_irq()              lock(desc)
  lock(desc)            handle_edge_irq()
                          handle_irq_event(desc)
                            set(INPROGRESS)
                            unlock(desc)
                            handle_irq_event_percpu(desc)
                            action = desc->action
  desc->action = NULL           while (action) {
                                  action->xxx
                                  ...
                                  action = action->next;
  sychronize_irq()
    while(INPROGRESS);      lock(desc)
                            clr(INPROGRESS)
free(action)

That's basically the same mechanism as we have for shared
interrupts. action->next can become NULL while handle_irq_event_percpu()
runs. Either it sees the action or NULL. It does not matter, because action
itself cannot go away before the interrupt in progress flag has been cleared.

Fixes: commit 71f64340fc0e "genirq: Remove the second parameter from handle_irq_event_percpu()"
Reported-by: zyjzyj2000@gmail.com
Signed-off-by: Thomas Gleixner 
Cc: Huang Shijie 
Cc: Jiang Liu 
Cc: Peter Zijlstra 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1601131224190.3575@nanos

Merge branch 'linus' into irq/core

2015-10-13T17:00:14+00:00

Bring in upstream updates for patches which depend on them

genirq: Fix handle_bad_irq kerneldoc comment

2015-10-09T15:17:30+00:00

A recent cleanup removed the 'irq' parameter from many functions, but
left the documentation for this in place for at least one function.

This removes it.

Fixes: bd0b9ac405e1 ("genirq: Remove irq argument from irq flow handlers")
Reported-by: kbuild test robot 
Signed-off-by: Arnd Bergmann 
Cc: Grygorii Strashko 
Cc: Tony Lindgren 
Cc: Linus Walleij 
Cc: kbuild-all@01.org
Cc: Austin Schuh 
Cc: Santosh Shilimkar 
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/5400000.cD19rmgWjV@wuerfel
Signed-off-by: Thomas Gleixner

genirq: Export handle_bad_irq

2015-10-09T15:17:30+00:00

A cleanup of the omap gpio driver introduced a use of the
handle_bad_irq() function in a device driver that can be
a loadable module.

This broke the ARM allmodconfig build:

ERROR: "handle_bad_irq" [drivers/gpio/gpio-omap.ko] undefined!

This patch exports the handle_bad_irq symbol in order to
allow the use in modules.

Signed-off-by: Arnd Bergmann 
Cc: Grygorii Strashko 
Cc: Santosh Shilimkar 
Cc: Linus Walleij 
Cc: Austin Schuh 
Cc: Tony Lindgren 
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/5847725.4IBopItaOr@wuerfel
Signed-off-by: Thomas Gleixner

genirq: Remove the second parameter from handle_irq_event_percpu()

2015-09-22T14:14:55+00:00

Actually, we always use the first irq action of the @desc->action
chain, so remove the second parameter from handle_irq_event_percpu()
which makes the code more tidy.

Signed-off-by: Huang Shijie 
Reviewed-by: Jiang Liu 
Cc: peterz@infradead.org
Cc: marc.zyngier@arm.com
Link: http://lkml.kernel.org/r/1441160695-19809-1-git-send-email-shijie.huang@arm.com
Signed-off-by: Thomas Gleixner

genirq: Remove irq argument from irq flow handlers

2015-09-16T13:47:51+00:00

Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!

Signed-off-by: Thomas Gleixner 
Cc: Julia Lawall 
Cc: Jiang Liu

genirq: Remove the irq argument from note_interrupt()

2015-07-11T21:14:25+00:00

Only required for the slow path. Retrieve it from irq descriptor if
necessary.

[ tglx: Split out from combo patch. Left [try_]misrouted_irq()
  	untouched as there is no win in the slow path ]

Signed-off-by: Jiang Liu 
Cc: Konrad Rzeszutek Wilk 
Cc: Tony Luck 
Cc: Bjorn Helgaas 
Cc: Benjamin Herrenschmidt 
Cc: Randy Dunlap 
Cc: Yinghai Lu 
Cc: Borislav Petkov 
Cc: Jason Cooper 
Cc: Kevin Cernekee 
Cc: Arnd Bergmann 
Link: http://lkml.kernel.org/r/1433391238-19471-19-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner

genirq: Remove the parameter 'irq' of kstat_incr_irqs_this_cpu()

2015-07-11T21:14:24+00:00

The first parameter 'irq' is never used by
kstat_incr_irqs_this_cpu(). Remove it.

Signed-off-by: Jiang Liu 
Cc: Konrad Rzeszutek Wilk 
Cc: Tony Luck 
Cc: Bjorn Helgaas 
Cc: Benjamin Herrenschmidt 
Cc: Randy Dunlap 
Cc: Yinghai Lu 
Cc: Borislav Petkov 
Link: http://lkml.kernel.org/r/1433391238-19471-16-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner