linux-toradex.git/kernel/irq/chip.c, branch v3.2-rc5

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: Make irq_shutdown() symmetric vs. irq_startup again

2011-09-12T07:38:53+00:00

If an irq_chip provides .irq_shutdown(), but neither of .irq_disable() or
.irq_mask(), free_irq() crashes when jumping to NULL.
Fix this by only trying .irq_disable() and .irq_mask() if there's no
.irq_shutdown() provided.

This revives the symmetry with irq_startup(), which tries .irq_startup(),
.irq_enable(), and irq_unmask(), and makes it consistent with the comment for
irq_chip.irq_shutdown() in , which says:

 * @irq_shutdown:	shut down the interrupt (defaults to ->disable if NULL)

This is also how __free_irq() behaved before the big overhaul, cfr. e.g.
3b56f0585fd4c02d047dc406668cb40159b2d340 ("genirq: Remove bogus conditional"),
where the core interrupt code always overrode .irq_shutdown() to
.irq_disable() if .irq_shutdown() was NULL.

Signed-off-by: Geert Uytterhoeven 
Cc: linux-m68k@lists.linux-m68k.org
Link: http://lkml.kernel.org/r/1315742394-16036-2-git-send-email-geert@linux-m68k.org
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner

irq: Export functions to allow modular irq drivers

2011-05-18T12:59:08+00:00

Export handle_simple_irq, irq_modify_status, irq_alloc_descs,
irq_free_descs and generic_handle_irq to allow their usage in
modules. First user is IIO, which wants to be built modular, but needs
to be able to create irq chips, allocate and configure interrupt
descriptors and handle demultiplexing interrupts.

[ tglx: Moved the uninlinig of generic_handle_irq to a separate patch ]

Signed-off-by: Jonathan Cameron 
Link: http://lkml.kernel.org/r/%3C1305711544-505-1-git-send-email-jic23%40cam.ac.uk%3E
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

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi

genirq: fix CONFIG_IRQ_EDGE_EOI_HANDLER build

2011-03-30T00:04:39+00:00

Fixes these errors:

  kernel/irq/chip.c: In function 'handle_edge_eoi_irq':
  kernel/irq/chip.c:517: warning: label 'out_unlock' defined but not used
  kernel/irq/chip.c:503: error: label 'out_eoi' used but not defined

Signed-off-by: Stephen Rothwell 
Signed-off-by: Linus Torvalds

genirq: Remove compat code

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

Signed-off-by: Thomas Gleixner

genirq; Fix cleanup fallout

2011-03-28T23:41:22+00:00

I missed the CONFIG_GENERIC_PENDING_IRQ dependency in the affinity
related functions and the IRQ_LEVEL propagation into irq_data
state. Did not pop up on my main test platforms. :(

Signed-off-by: Thomas Gleixner 
Tested-by: David Daney

genirq: Provide edge_eoi flow handler

2011-03-28T14:55:11+00:00

This is a replacment for the cell flow handler which is in the way of
cleanups. Must be selected to avoid general bloat.

Signed-off-by: Thomas Gleixner

genirq: Move INPROGRESS, MASKED and DISABLED state flags to irq_data

2011-03-28T14:55:10+00:00

We really need these flags for some of the interrupt chips. Move it
from internal state to irq_data and provide proper accessors.

Signed-off-by: Thomas Gleixner 
Cc: David Daney