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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-06-16 23:06:20 +0100
committerThomas Gleixner <tglx@linutronix.de>2015-06-18 14:03:08 +0200
commit3b0f95be143bea1aa47beb20134ef82e4e4068dc (patch)
tree730822397420dd40a9cf50d8b3bc26e829522ef5 /kernel/irq
parent6fd4899a54a522ccd6a24fea2318d3b515b95945 (diff)
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irq: Add irq_set_chained_handler_and_data()
Driver authors seem to get the ordering of irq_set_chained_handler() and irq_set_handler_data() wrong - ordering the former before the latter. This opens a race window where, if there is an interrupt pending, the handler will be called between these two calls, potentially resulting in an oops. Provide a single interface to set both of these together, especially as that's commonly what is required. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Lee Jones <lee.jones@linaro.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/E1Z4yzs-0002Rw-4B@rmk-PC.arm.linux.org.uk Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/chip.c45
1 files changed, 34 insertions, 11 deletions
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 330fc797e632..27f4332c7f84 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -719,15 +719,9 @@ void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc)
}
void
-__irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
- const char *name)
+__irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
+ int is_chained, const char *name)
{
- unsigned long flags;
- struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
-
- if (!desc)
- return;
-
if (!handle) {
handle = handle_bad_irq;
} else {
@@ -749,13 +743,13 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
* right away.
*/
if (WARN_ON(is_chained))
- goto out;
+ return;
/* Try the parent */
irq_data = irq_data->parent_data;
}
#endif
if (WARN_ON(!irq_data || irq_data->chip == &no_irq_chip))
- goto out;
+ return;
}
/* Uninstall? */
@@ -774,12 +768,41 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
irq_settings_set_nothread(desc);
irq_startup(desc, true);
}
-out:
+}
+
+void
+__irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
+ const char *name)
+{
+ unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
+
+ if (!desc)
+ return;
+
+ __irq_do_set_handler(desc, handle, is_chained, name);
irq_put_desc_busunlock(desc, flags);
}
EXPORT_SYMBOL_GPL(__irq_set_handler);
void
+irq_set_chained_handler_and_data(unsigned int irq, irq_flow_handler_t handle,
+ void *data)
+{
+ unsigned long flags;
+ struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, 0);
+
+ if (!desc)
+ return;
+
+ __irq_do_set_handler(desc, handle, 1, NULL);
+ desc->irq_data.handler_data = data;
+
+ irq_put_desc_busunlock(desc, flags);
+}
+EXPORT_SYMBOL_GPL(irq_set_chained_handler_and_data);
+
+void
irq_set_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
irq_flow_handler_t handle, const char *name)
{