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authorMarc Zyngier <marc.zyngier@arm.com>2014-08-26 14:03:16 +0400
committerJason Cooper <jason@lakedaemon.net>2014-09-03 16:57:27 +0400
commit76ba59f8366f2d9282cb5bda9de75b4b68cbe55f (patch)
tree567c5a7b10fb8f7a1e597a8cc83c0afe92dbce50 /include/linux/irqdesc.h
parent7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9 (diff)
downloadlinux-76ba59f8366f2d9282cb5bda9de75b4b68cbe55f.tar.xz
genirq: Add irq_domain-aware core IRQ handler
Calling irq_find_mapping from outside a irq_{enter,exit} section is unsafe and produces ugly messages if CONFIG_PROVE_RCU is enabled: If coming from the idle state, the rcu_read_lock call in irq_find_mapping will generate an unpleasant warning: <quote> =============================== [ INFO: suspicious RCU usage. ] 3.16.0-rc1+ #135 Not tainted ------------------------------- include/linux/rcupdate.h:871 rcu_read_lock() used illegally while idle! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 1 lock held by swapper/0/0: #0: (rcu_read_lock){......}, at: [<ffffffc00010206c>] irq_find_mapping+0x4c/0x198 </quote> As this issue is fairly widespread and involves at least three different architectures, a possible solution is to add a new handle_domain_irq entry point into the generic IRQ code that the interrupt controller code can call. This new function takes an irq_domain, and calls into irq_find_domain inside the irq_{enter,exit} block. An additional "lookup" parameter is used to allow non-domain architecture code to be replaced by this as well. Interrupt controllers can then be updated to use the new mechanism. This code is sitting behind a new CONFIG_HANDLE_DOMAIN_IRQ, as not all architectures implement set_irq_regs (yes, mn10300, I'm looking at you...). Reported-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/1409047421-27649-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Diffstat (limited to 'include/linux/irqdesc.h')
-rw-r--r--include/linux/irqdesc.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 472c021a2d4f..ff24667cd86c 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -12,6 +12,8 @@ struct irq_affinity_notify;
struct proc_dir_entry;
struct module;
struct irq_desc;
+struct irq_domain;
+struct pt_regs;
/**
* struct irq_desc - interrupt descriptor
@@ -118,6 +120,23 @@ static inline void generic_handle_irq_desc(unsigned int irq, struct irq_desc *de
int generic_handle_irq(unsigned int irq);
+#ifdef CONFIG_HANDLE_DOMAIN_IRQ
+/*
+ * Convert a HW interrupt number to a logical one using a IRQ domain,
+ * and handle the result interrupt number. Return -EINVAL if
+ * conversion failed. Providing a NULL domain indicates that the
+ * conversion has already been done.
+ */
+int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
+ bool lookup, struct pt_regs *regs);
+
+static inline int handle_domain_irq(struct irq_domain *domain,
+ unsigned int hwirq, struct pt_regs *regs)
+{
+ return __handle_domain_irq(domain, hwirq, true, regs);
+}
+#endif
+
/* Test to see if a driver has successfully requested an irq */
static inline int irq_has_action(unsigned int irq)
{