irqdesc: Add domain handler for NMIs

NMI handling code should be executed between calls to nmi_enter and
nmi_exit.

Add a separate domain handler to properly setup NMI context when handling
an interrupt requested as NMI.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index dd1e40d..ba05b0d 100644 (file)
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -171,6 +171,11 @@ static inline int handle_domain_irq(struct irq_domain *domain,
 {
        return __handle_domain_irq(domain, hwirq, true, regs);
 }
+
+#ifdef CONFIG_IRQ_DOMAIN
+int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
+                     struct pt_regs *regs);
+#endif
 #endif
 
 /* Test to see if a driver has successfully requested an irq */

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index ee062b7..a1d7a7d 100644 (file)
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -669,6 +669,41 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
        set_irq_regs(old_regs);
        return ret;
 }
+
+#ifdef CONFIG_IRQ_DOMAIN
+/**
+ * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain
+ * @domain:    The domain where to perform the lookup
+ * @hwirq:     The HW irq number to convert to a logical one
+ * @regs:      Register file coming from the low-level handling code
+ *
+ * Returns:    0 on success, or -EINVAL if conversion has failed
+ */
+int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
+                     struct pt_regs *regs)
+{
+       struct pt_regs *old_regs = set_irq_regs(regs);
+       unsigned int irq;
+       int ret = 0;
+
+       nmi_enter();
+
+       irq = irq_find_mapping(domain, hwirq);
+
+       /*
+        * ack_bad_irq is not NMI-safe, just report
+        * an invalid interrupt.
+        */
+       if (likely(irq))
+               generic_handle_irq(irq);
+       else
+               ret = -EINVAL;
+
+       nmi_exit();
+       set_irq_regs(old_regs);
+       return ret;
+}
+#endif
 #endif
 
 /* Dynamic interrupt handling */