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-rw-r--r--arch/alpha/kernel/irq_srm.c65
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 0000000000..bfacd6a061
--- /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);
+}