1 files changed, 65 insertions, 0 deletions
diff --git a/arch/alpha/kernel/irq_srm.c b/arch/alpha/kernel/irq_srm.c
new file mode 100644
index 000000000..bfacd6a06
--- /dev/null
+++ b/arch/alpha/kernel/irq_srm.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Handle interrupts from the SRM, assuming no additional weirdness.
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/irq.h>
+
+#include "proto.h"
+#include "irq_impl.h"
+
+
+/*
+ * Is the palcode SMP safe? In other words: can we call cserve_ena/dis
+ * at the same time in multiple CPUs? To be safe I added a spinlock
+ * but it can be removed trivially if the palcode is robust against smp.
+ */
+DEFINE_SPINLOCK(srm_irq_lock);
+
+static inline void
+srm_enable_irq(struct irq_data *d)
+{
+	spin_lock(&srm_irq_lock);
+	cserve_ena(d->irq - 16);
+	spin_unlock(&srm_irq_lock);
+}
+
+static void
+srm_disable_irq(struct irq_data *d)
+{
+	spin_lock(&srm_irq_lock);
+	cserve_dis(d->irq - 16);
+	spin_unlock(&srm_irq_lock);
+}
+
+/* Handle interrupts from the SRM, assuming no additional weirdness.  */
+static struct irq_chip srm_irq_type = {
+	.name		= "SRM",
+	.irq_unmask	= srm_enable_irq,
+	.irq_mask	= srm_disable_irq,
+	.irq_mask_ack	= srm_disable_irq,
+};
+
+void __init
+init_srm_irqs(long max, unsigned long ignore_mask)
+{
+	long i;
+
+	if (NR_IRQS <= 16)
+		return;
+	for (i = 16; i < max; ++i) {
+		if (i < 64 && ((ignore_mask >> i) & 1))
+			continue;
+		irq_set_chip_and_handler(i, &srm_irq_type, handle_level_irq);
+		irq_set_status_flags(i, IRQ_LEVEL);
+	}
+}
+
+void 
+srm_device_interrupt(unsigned long vector)
+{
+	int irq = (vector - 0x800) >> 4;
+	handle_irq(irq);
+}