[Qemu-devel] [PATCH v5 5/8] irq: Add a new irq device that allows the ORing of lines

[Alistair Francis]

Signed-off-by: Alistair Francis <alist...@alistair23.me>
---

 hw/core/irq.c    | 44 ++++++++++++++++++++++++++++++++++++++++++++
 include/hw/irq.h | 13 +++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/hw/core/irq.c b/hw/core/irq.c
index 49ff2e6..73b18b4 100644
--- a/hw/core/irq.c
+++ b/hw/core/irq.c
@@ -27,6 +27,7 @@
 #include "qom/object.h"
 
 #define IRQ(obj) OBJECT_CHECK(struct IRQState, (obj), TYPE_IRQ)
+#define OR_IRQ(obj) OBJECT_CHECK(struct OrIRQState, (obj), TYPE_OR_IRQ)
 
 struct IRQState {
     Object parent_obj;
@@ -36,6 +37,15 @@ struct IRQState {
     int n;
 };
 
+struct OrIRQState {
+    Object parent_obj;
+
+    qemu_irq in_irq;
+    qemu_irq *out_irqs;
+    int *levels;
+    int n;
+};
+
 void qemu_set_irq(qemu_irq irq, int level)
 {
     if (!irq)
@@ -77,6 +87,33 @@ qemu_irq qemu_allocate_irq(qemu_irq_handler handler, void 
*opaque, int n)
     return irq;
 }
 
+static void or_irq_handler(void *opaque, int n, int level)
+{
+    qemu_or_irq or_irq = (qemu_or_irq) opaque;
+    int or_level = 0;
+    int i;
+
+    or_irq->levels[n] = level;
+
+    for (i = 0; i < or_irq->n; i++) {
+        or_level |= or_irq->levels[i];
+    }
+
+    qemu_set_irq(or_irq->in_irq, or_level);
+}
+
+qemu_irq *qemu_allocate_or_irqs(qemu_irq in_irq, int n)
+{
+    qemu_or_irq or_irq = OR_IRQ(object_new(TYPE_OR_IRQ));
+
+    or_irq->out_irqs = qemu_allocate_irqs(or_irq_handler, or_irq, n);
+    or_irq->in_irq = in_irq;
+    or_irq->levels = g_new(int, n);
+    or_irq->n = n;
+
+    return or_irq->out_irqs;
+}
+
 void qemu_free_irqs(qemu_irq *s, int n)
 {
     int i;
@@ -151,9 +188,16 @@ static const TypeInfo irq_type_info = {
    .instance_size = sizeof(struct IRQState),
 };
 
+static const TypeInfo or_irq_type_info = {
+   .name = TYPE_OR_IRQ,
+   .parent = TYPE_OBJECT,
+   .instance_size = sizeof(struct OrIRQState),
+};
+
 static void irq_register_types(void)
 {
     type_register_static(&irq_type_info);
+    type_register_static(&or_irq_type_info);
 }
 
 type_init(irq_register_types)
diff --git a/include/hw/irq.h b/include/hw/irq.h
index 4c4c2ea..aeb7eb7 100644
--- a/include/hw/irq.h
+++ b/include/hw/irq.h
@@ -4,8 +4,10 @@
 /* Generic IRQ/GPIO pin infrastructure.  */
 
 #define TYPE_IRQ "irq"
+#define TYPE_OR_IRQ "or-irq"
 
 typedef struct IRQState *qemu_irq;
+typedef struct OrIRQState *qemu_or_irq;
 
 typedef void (*qemu_irq_handler)(void *opaque, int n, int level);
 
@@ -38,6 +40,17 @@ qemu_irq *qemu_allocate_irqs(qemu_irq_handler handler, void 
*opaque, int n);
  */
 qemu_irq qemu_allocate_irq(qemu_irq_handler handler, void *opaque, int n);
 
+/*
+ * qemu_allocate_or_irqs
+ * @in_irq: An input IRQ. It will be the result of the @out_irqs ORed together
+ * @n: The number of interrupt lines that should be ORed together
+ *
+ * returns: An array of interrupts that should be ORed together
+ *
+ * OR all of the interrupts returned in the array into a single @in_irq.
+ */
+qemu_irq *qemu_allocate_or_irqs(qemu_irq in_irq, int n);
+
 /* Extends an Array of IRQs. Old IRQs have their handlers and opaque data
  * preserved. New IRQs are assigned the argument handler and opaque data.
  */
-- 
2.7.4