Commit Graph

7 Commits

Author SHA1 Message Date
Nishanth Menon ddee0fb46d irqchip: crossbar: Change allocation logic by reversing search for free irqs
Reverse the search algorithm to ensure that address mapping and IRQ
allocation logics are proper. This makes the below bugs visible sooner.

class 1. address space errors -> example:
reg = <a size_b>
ti,max-irqs =  is a wrong parameter

class 2: irq-reserved list - which decides which entries in the
address space is not actually wired in

class 3: wrong list of routable-irqs.

In general allocating from max to min tends to have benefits in
ensuring the different issues that may be present in dts is easily
caught at definition time, rather than at a later point in time.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-6-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-06-30 19:11:21 +00:00
Nishanth Menon a35057d1dc irqchip: crossbar: Initialise the crossbar with a safe value
Since crossbar is s/w configurable, the initial settings of the
crossbar cannot be assumed to be sane. This implies that:
a) On initialization all un-reserved crossbars must be initialized to
   a known 'safe' value.
b) When unmapping the interrupt, the safe value must be written to
   ensure that the crossbar mapping matches with interrupt controller
   usage.

So provide a safe value in the dt data to map if
'0' is not safe for the platform and use it during init and unmap

While at this, fix the below checkpatch warning.
Fixes checkpatch warning:
WARNING: Unnecessary space before function pointer arguments
 #37: FILE: drivers/irqchip/irq-crossbar.c:37:
 +	void (*write) (int, int);

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-5-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-06-30 19:11:20 +00:00
Nishanth Menon 64e0f8ba5c irqchip: crossbar: Introduce ti, irqs-skip to skip irqs that bypass crossbar
When, in the system due to varied reasons, interrupts might be unusable
due to hardware behavior, but register maps do exist, then those interrupts
should be skipped while mapping irq to crossbars.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-4-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-06-30 19:11:18 +00:00
Nishanth Menon 6f16fc878a irqchip: crossbar: Check for premapped crossbar before allocating
If irq_of_parse_and_map is executed twice, the same crossbar is mapped to two
different GIC interrupts. This is completely undesirable. Instead, check
if the requested crossbar event is pre-allocated and provide that GIC
mapping back to caller if already allocated.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-3-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-06-30 19:11:17 +00:00
Nishanth Menon 1d50d2ce63 irqchip: crossbar: Dont use '0' to mark reserved interrupts
Today '0' is actually reserved, but may not be the same in the future.

So, use a flag to mark the GIC interrupts that are reserved.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-2-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-06-30 19:11:16 +00:00
Dan Carpenter 3894e9e82d irqchip: irq-crossbar: Not allocating enough memory
We are allocating the size of a pointer and not the size of the data.
This will lead to memory corruption.

There isn't actually a "cb_device" struct, btw.  The code is only able
to compile because GCC knows that all pointers are the same size.

Fixes: 96ca848ef7 ('DRIVERS: IRQCHIP: CROSSBAR: Add support for Crossbar IP')

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Sricharan R <r.sricharan@ti.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/20140403072134.GA14286@mwanda
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-04-28 21:43:24 +02:00
Sricharan R 96ca848ef7 DRIVERS: IRQCHIP: CROSSBAR: Add support for Crossbar IP
Some socs have a large number of interrupts requests to service
the needs of its many peripherals and subsystems. All of the
interrupt lines from the subsystems are not needed at the same
time, so they have to be muxed to the irq-controller appropriately.
In such places a interrupt controllers are preceded by an CROSSBAR
that provides flexibility in muxing the device requests to the controller
inputs.

This driver takes care a allocating a free irq and then configuring the
crossbar IP as a part of the mpu's irqchip callbacks. crossbar_init should
be called right before the irqchip_init, so that it is setup to handle the
irqchip callbacks.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Kumar Gala <galak@codeaurora.org> (for DT binding portion)
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2014-02-05 20:08:34 +05:30