Commit Graph

20 Commits

Author SHA1 Message Date
Thomas Gleixner e9849777d0 genirq: Add flag to force mask in disable_irq[_nosync]()
If an irq chip does not implement the irq_disable callback, then we
use a lazy approach for disabling the interrupt. That means that the
interrupt is marked disabled, but the interrupt line is not
immediately masked in the interrupt chip. It only becomes masked if
the interrupt is raised while it's marked disabled. We use this to avoid
possibly expensive mask/unmask operations for common case operations.

Unfortunately there are devices which do not allow the interrupt to be
disabled easily at the device level. They are forced to use
disable_irq_nosync(). This can result in taking each interrupt twice.

Instead of enforcing the non lazy mode on all interrupts of a irq
chip, provide a settings flag, which can be set by the driver for that
particular interrupt line.

Reported-and-tested-by: Duc Dang <dhdang@apm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1510092348370.6097@nanos
2015-10-11 11:33:42 +02:00
Thomas Gleixner b39898cd40 genirq: Prevent spurious detection for unconditionally polled interrupts
On a 68k platform a couple of interrupts are demultiplexed and
"polled" from a top level interrupt. Unfortunately there is no way to
determine which of the sub interrupts raised the top level interrupt,
so all of the demultiplexed interrupt handlers need to be
invoked. Given a high enough frequency this can trigger the spurious
interrupt detection mechanism, if one of the demultiplex interrupts
returns IRQ_NONE continuously. But this is a false positive as the
polling causes this behaviour and not buggy hardware/software.

Introduce IRQ_POLLED which can be set at interrupt chip setup time via
irq_set_status_flags(). The flag excludes the interrupt from the
spurious detector and from all core polling activities.

Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1311061149250.23353@ionos.tec.linutronix.de
2013-11-13 16:03:02 +01:00
Marc Zyngier 31d9d9b6d8 genirq: Add support for per-cpu dev_id interrupts
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 <marc.zyngier@arm.com>
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 <tglx@linutronix.de>
2011-10-03 15:35:26 +02:00
Paul Mundt 7f1b1244e1 genirq: Support per-IRQ thread disabling.
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 <lethal@linux-sh.org>
Link: http://lkml.kernel.org/r/%3C20110406210135.GF18426%40linux-sh.org%3E
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-04-23 15:56:24 +02:00
Thomas Gleixner 0c6f8a8b91 genirq: Remove compat code
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-29 14:48:19 +02:00
Thomas Gleixner a6967caf00 genirq: Remove desc->status when GENERIC_HARDIRQS_NO_COMPAT=y
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 <tglx@linutronix.de>
2011-02-19 12:58:22 +01:00
Thomas Gleixner 5d4d8fc9ac genirq: Cleanup irq.h
Put the constants into an enum and document them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:21 +01:00
Thomas Gleixner f9e4989eb8 genirq: Force wrapped access to desc->status in core code
Force the usage of wrappers by another nasty CPP substitution.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:21 +01:00
Thomas Gleixner 1ccb4e612f genirq: Wrap the remaning IRQ_* flags
Use wrappers to keep them away from the core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:21 +01:00
Thomas Gleixner 876dbd4cc1 genirq: Mirror irq trigger type bits in irq_data.state
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 <tglx@linutronix.de>
2011-02-19 12:58:20 +01:00
Thomas Gleixner 2bdd10558c genirq: Move IRQ_AFFINITY_SET to core
Keep status in sync until last abuser is gone.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:20 +01:00
Thomas Gleixner a005677b3d genirq: Mirror IRQ_PER_CPU and IRQ_NO_BALANCING in irq_data.state
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 <tglx@linutronix.de>
2011-02-19 12:58:20 +01:00
Thomas Gleixner f230b6d5c4 genirq: Add IRQ_MOVE_PENDING to irq_data.state
chip implementations need to know about it. Keep status in sync until
all users are fixed. 

Accessor function: irqd_is_setaffinity_pending(irqdata)

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

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:18 +01:00
Thomas Gleixner 6d2cd17fde genirq: Move IRQ_WAKEUP to core
No users outside of core.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:18 +01:00
Thomas Gleixner 6e40262ea4 genirq: Move IRQ_MASKED to core
Keep status in sync until all users are fixed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:17 +01:00
Thomas Gleixner 2a0d6fb335 genirq: Move IRQ_PENDING flag to core
Keep status in sync until all users are fixed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:17 +01:00
Thomas Gleixner c1594b77e4 genirq: Move IRQ_DISABLED to core
Keep status in sync until all abusers are fixed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:17 +01:00
Thomas Gleixner 163ef30911 genirq: Move IRQ_REPLAY and IRQ_WAITING to core
No users outside of core.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:16 +01:00
Thomas Gleixner 009b4c3b8a genirq: Add IRQ_INPROGRESS to core
We need to maintain the flag for now in both fields status and istate.
Add a CONFIG_GENERIC_HARDIRQS_NO_COMPAT switch to allow testing w/o
the status one. Wrap the access to status IRQ_INPROGRESS in a inline
which can be turned of with CONFIG_GENERIC_HARDIRQS_NO_COMPAT along
with the define.

There is no reason that anything outside of core looks at this. That
needs some modifications, but we'll get there.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:16 +01:00
Thomas Gleixner e6bea9c404 genirq: Protect tglx from tripping over his own feet
The irq_desc.status field will either go away or renamed to
settings. Anyway we need to maintain compatibility to avoid breaking
the world and some more. While moving bits into the core, I need to
avoid that I use any of the still existing IRQ_ bits in the core code
by typos. So that file will hold the inline wrappers and some nasty
CPP tricks to break the build when typoed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:14 +01:00