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authorMarc Zyngier <marc.zyngier@arm.com>2015-03-18 14:01:22 +0300
committerThomas Gleixner <tglx@linutronix.de>2015-04-09 00:28:28 +0300
commit1b7047edfcfb257f69e306c9afbab150cb987717 (patch)
tree68b2383acee6ce6a58900507e797e9c6178e4a5b /include/linux/irq.h
parentfe0c52fc003bc046380e52fe6799c96d770770cc (diff)
downloadlinux-1b7047edfcfb257f69e306c9afbab150cb987717.tar.xz
genirq: Allow the irqchip state of an IRQ to be save/restored
There is a number of cases where a kernel subsystem may want to introspect the state of an interrupt at the irqchip level: - When a peripheral is shared between virtual machines, its interrupt state becomes part of the guest's state, and must be switched accordingly. KVM on arm/arm64 requires this for its guest-visible timer - Some GPIO controllers seem to require peeking into the interrupt controller they are connected to to report their internal state This seem to be a pattern that is common enough for the core code to try and support this without too many horrible hacks. Introduce a pair of accessors (irq_get_irqchip_state/irq_set_irqchip_state) to retrieve the bits that can be of interest to another subsystem: pending, active, and masked. - irq_get_irqchip_state returns the state of the interrupt according to a parameter set to IRQCHIP_STATE_PENDING, IRQCHIP_STATE_ACTIVE, IRQCHIP_STATE_MASKED or IRQCHIP_STATE_LINE_LEVEL. - irq_set_irqchip_state similarly sets the state of the interrupt. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Tested-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Abhijeet Dharmapurikar <adharmap@codeaurora.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Phong Vo <pvo@apm.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Tin Huynh <tnhuynh@apm.com> Cc: Y Vo <yvo@apm.com> Cc: Toan Le <toanle@apm.com> Cc: Bjorn Andersson <bjorn@kryo.se> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/1426676484-21812-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/irq.h')
-rw-r--r--include/linux/irq.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index d09ec7a1243e..77dd2e7f93f4 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -30,6 +30,7 @@
struct seq_file;
struct module;
struct msi_msg;
+enum irqchip_irq_state;
/*
* IRQ line status.
@@ -324,6 +325,8 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
* irq_request_resources
* @irq_compose_msi_msg: optional to compose message content for MSI
* @irq_write_msi_msg: optional to write message content for MSI
+ * @irq_get_irqchip_state: return the internal state of an interrupt
+ * @irq_set_irqchip_state: set the internal state of a interrupt
* @flags: chip specific flags
*/
struct irq_chip {
@@ -363,6 +366,9 @@ struct irq_chip {
void (*irq_compose_msi_msg)(struct irq_data *data, struct msi_msg *msg);
void (*irq_write_msi_msg)(struct irq_data *data, struct msi_msg *msg);
+ int (*irq_get_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool *state);
+ int (*irq_set_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool state);
+
unsigned long flags;
};