linux-toradex.git/kernel/irq/settings.h, branch v3.10.78

genirq: Add support for per-cpu dev_id interrupts

2011-10-03T13:35:26+00:00

The ARM GIC interrupt controller offers per CPU interrupts (PPIs),
which are usually used to connect local timers to each core. Each CPU
has its own private interface to the GIC, and only sees the PPIs that
are directly connect to it.

While these timers are separate devices and have a separate interrupt
line to a core, they all use the same IRQ number.

For these devices, request_irq() is not the right API as it assumes
that an IRQ number is visible by a number of CPUs (through the
affinity setting), but makes it very awkward to express that an IRQ
number can be handled by all CPUs, and yet be a different interrupt
line on each CPU, requiring a different dev_id cookie to be passed
back to the handler.

The *_percpu_irq() functions is designed to overcome these
limitations, by providing a per-cpu dev_id vector:

int request_percpu_irq(unsigned int irq, irq_handler_t handler,
		   const char *devname, void __percpu *percpu_dev_id);
void free_percpu_irq(unsigned int, void __percpu *);
int setup_percpu_irq(unsigned int irq, struct irqaction *new);
void remove_percpu_irq(unsigned int irq, struct irqaction *act);
void enable_percpu_irq(unsigned int irq);
void disable_percpu_irq(unsigned int irq);

The API has a number of limitations:
- no interrupt sharing
- no threading
- common handler across all the CPUs

Once the interrupt is requested using setup_percpu_irq() or
request_percpu_irq(), it must be enabled by each core that wishes its
local interrupt to be delivered.

Based on an initial patch by Thomas Gleixner.

Signed-off-by: Marc Zyngier 
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner

genirq: Support per-IRQ thread disabling.

2011-04-23T13:56:24+00:00

This adds support for disabling threading on a per-IRQ basis via the IRQ
status instead of the IRQ flow, which is necessary for interrupts that
don't follow the natural IRQ flow channels, such as those that are
virtually created.

The new APIs added are simply:

	irq_set_thread()
	irq_set_nothread()

which follow the rest of the IRQ status routines.

Chained handlers also have IRQ_NOTHREAD set on them automatically, making
the lack of threading explicit rather than implicit. Subsequently, the
nothread flag can be viewed through the standard genirq debugging
facilities.

[ tglx: Fixed cleanup fallout ]

Signed-off-by: Paul Mundt 
Link: http://lkml.kernel.org/r/%3C20110406210135.GF18426%40linux-sh.org%3E
Signed-off-by: Thomas Gleixner

genirq: Remove compat code

2011-03-29T12:48:19+00:00

Signed-off-by: Thomas Gleixner

genirq: Remove desc->status when GENERIC_HARDIRQS_NO_COMPAT=y

2011-02-19T11:58:22+00:00

If everything uses the right accessors, then enabling
GENERIC_HARDIRQS_NO_COMPAT should just work. If not it will tell you.

Don't be lazy and use the trick which I use in the core code!

git grep status_use_accessors

will unearth it in a split second. Offenders are tracked down and not
slapped with stinking trouts. This time we use frozen shark for a
better educational value.

Signed-off-by: Thomas Gleixner

genirq: Cleanup irq.h

2011-02-19T11:58:21+00:00

Put the constants into an enum and document them.

Signed-off-by: Thomas Gleixner

genirq: Force wrapped access to desc->status in core code

2011-02-19T11:58:21+00:00

Force the usage of wrappers by another nasty CPP substitution.

Signed-off-by: Thomas Gleixner

genirq: Wrap the remaning IRQ_* flags

2011-02-19T11:58:21+00:00

Use wrappers to keep them away from the core code.

Signed-off-by: Thomas Gleixner

genirq: Mirror irq trigger type bits in irq_data.state

2011-02-19T11:58:20+00:00

That's the data structure chip functions get provided. Also allow them
to signal the core code that they updated the flags in irq_data.state
by returning IRQ_SET_MASK_OK_NOCOPY. The default is unchanged.

The type bits should be accessed via:

val = irqd_get_trigger_type(irqdata);
and
irqd_set_trigger_type(irqdata, val);

Coders who access them directly will be tracked down and slapped with
stinking trouts.

Signed-off-by: Thomas Gleixner

genirq: Move IRQ_AFFINITY_SET to core

2011-02-19T11:58:20+00:00

Keep status in sync until last abuser is gone.

Signed-off-by: Thomas Gleixner

genirq: Mirror IRQ_PER_CPU and IRQ_NO_BALANCING in irq_data.state

2011-02-19T11:58:20+00:00

That's the right data structure to look at for arch code.

Accessor functions are provided.

	 irqd_is_per_cpu(irqdata);
	 irqd_can_balance(irqdata);

Coders who access them directly will be tracked down and slapped with
stinking trouts.

Signed-off-by: Thomas Gleixner