genirq: irqchip: Add a mask calculation function

Some chips have weird bit mask access patterns instead of the linear
you expect. Allow them to calculate the cached mask themself.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20130506142539.302898834@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 6 insertions, 2 deletions

diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
index 957155cebbac..5068fe3ae1af 100644
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -240,6 +240,7 @@ void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
                             unsigned int set)
 {
         struct irq_chip_type *ct = gc->chip_types;
+        struct irq_chip *chip = &ct->chip;
         unsigned int i;
         u32 *mskptr = &gc->mask_cache, mskreg = ct->regs.mask;
 
@@ -267,9 +268,12 @@ void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
                 if (!(flags & IRQ_GC_NO_MASK)) {
                         struct irq_data *d = irq_get_irq_data(i);
 
-                        d->mask = 1 << (i - gc->irq_base);
+                        if (chip->irq_calc_mask)
+                                chip->irq_calc_mask(d);
+                        else
+                                d->mask = 1 << (i - gc->irq_base);
                 }
-                irq_set_chip_and_handler(i, &ct->chip, ct->handler);
+                irq_set_chip_and_handler(i, chip, ct->handler);
                 irq_set_chip_data(i, gc);
                 irq_modify_status(i, clr, set);
         }