[PATCH 3.16 028/306] genirq/generic_chip: Add irq_unmap callback

Ben Hutchings
2017-02-15T23:18:55Z

From: Sebastian Frias <sf84@laposte.net>

commit ee26c013cdee0b947e29d6cadfb9ff3341c69ff9 upstream.

Without this patch irq_domain_disassociate() cannot properly release the
interrupt. In fact, irq_map_generic_chip() checks a bit on 'gc->installed'
but said bit is never cleared, only set.

Commit 088f40b7b027 ("genirq: Generic chip: Add linear irq domain support")
added irq_map_generic_chip() function and also stated "This lacks a removal
function for now".

This commit provides an implementation of an unmap function that can be
called by irq_domain_disassociate().

[ tglx: Made the function static and removed the export as we have neither
a prototype nor a modular user. ]

Fixes: 088f40b7b027 ("genirq: Generic chip: Add linear irq domain support")
Signed-off-by: Sebastian Frias <sf84@laposte.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mason <slash.tmp@free.fr>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/579F5C5A.2070507@laposte.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.16: open-code irq_domain_get_irq_data(),
irq_domain_set_info()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -395,8 +395,30 @@ static int irq_map_generic_chip(struct i
return 0;
}

+static void irq_unmap_generic_chip(struct irq_domain *d, unsigned int virq)
+{
+ struct irq_data *data = irq_get_irq_data(virq);
+ struct irq_domain_chip_generic *dgc = d->gc;
+ unsigned int hw_irq = data->hwirq;
+ struct irq_chip_generic *gc;
+ int irq_idx;
+
+ gc = irq_get_domain_generic_chip(d, hw_irq);
+ if (!gc)
+ return;
+
+ irq_idx = hw_irq % dgc->irqs_per_chip;
+
+ clear_bit(irq_idx, &gc->installed);
+ data->chip = &no_irq_chip;
+ data->chip_data = NULL;
+ __irq_set_handler(virq, NULL, 0, NULL);
+ irq_set_handler_data(virq, NULL);
+}
+
struct irq_domain_ops irq_generic_chip_ops = {
.map = irq_map_generic_chip,
+ .unmap = irq_unmap_generic_chip,
.xlate = irq_domain_xlate_onetwocell,
};
EXPORT_SYMBOL_GPL(irq_generic_chip_ops);