genirq: Provide edge_eoi flow handler

This is a replacment for the cell flow handler which is in the way of
cleanups. Must be selected to avoid general bloat.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 50 insertions, 0 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 18aacccb0fae..44ebca745789 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -423,6 +423,7 @@ extern irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action);
 extern void handle_level_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_edge_irq(unsigned int irq, struct irq_desc *desc);
+extern void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_simple_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_percpu_irq(unsigned int irq, struct irq_desc *desc);
 extern void handle_bad_irq(unsigned int irq, struct irq_desc *desc);
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 00f2c037267a..72606ba10b14 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -51,6 +51,10 @@ config HARDIRQS_SW_RESEND
 config IRQ_PREFLOW_FASTEOI
        bool
 
+# Edge style eoi based handler (cell)
+config IRQ_EDGE_EOI_HANDLER
+       bool
+
 # Support forced irq threading
 config IRQ_FORCED_THREADING
        bool
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index e00bdc56269f..451d1e81c15c 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -604,6 +604,51 @@ out_unlock:
         raw_spin_unlock(&desc->lock);
 }
 
+#ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
+/**
+ *      handle_edge_eoi_irq - edge eoi type IRQ handler
+ *      @irq:   the interrupt number
+ *      @desc:  the interrupt description structure for this irq
+ *
+ * Similar as the above handle_edge_irq, but using eoi and w/o the
+ * mask/unmask logic.
+ */
+void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
+{
+        struct irq_chip *chip = irq_desc_get_chip(desc);
+
+        raw_spin_lock(&desc->lock);
+
+        desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
+        /*
+         * If we're currently running this IRQ, or its disabled,
+         * we shouldn't process the IRQ. Mark it pending, handle
+         * the necessary masking and go out
+         */
+        if (unlikely(irqd_irq_disabled(&desc->irq_data) ||
+                     irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
+                if (!irq_check_poll(desc)) {
+                        desc->istate |= IRQS_PENDING;
+                        goto out_eoi;
+                }
+        }
+        kstat_incr_irqs_this_cpu(irq, desc);
+
+        do {
+                if (unlikely(!desc->action))
+                        goto out_eoi;
+
+                handle_irq_event(desc);
+
+        } while ((desc->istate & IRQS_PENDING) &&
+                 !irqd_irq_disabled(&desc->irq_data));
+
+out_unlock:
+        chip->irq_eoi(&desc->irq_data);
+        raw_spin_unlock(&desc->lock);
+}
+#endif
+
 /**
  *      handle_percpu_irq - Per CPU local irq handler
  *      @irq:   the interrupt number