1 files changed, 59 insertions, 0 deletions
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
new file mode 100644
index 000000000..06c3c2fb4
--- /dev/null
+++ b/arch/x86/xen/irq.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/hardirq.h>
+
+#include <asm/x86_init.h>
+
+#include <xen/interface/xen.h>
+#include <xen/interface/sched.h>
+#include <xen/interface/vcpu.h>
+#include <xen/features.h>
+#include <xen/events.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/xen/hypervisor.h>
+
+#include "xen-ops.h"
+
+/*
+ * Force a proper event-channel callback from Xen after clearing the
+ * callback mask. We do this in a very simple manner, by making a call
+ * down into Xen. The pending flag will be checked by Xen on return.
+ */
+noinstr void xen_force_evtchn_callback(void)
+{
+	(void)HYPERVISOR_xen_version(0, NULL);
+}
+
+static void xen_safe_halt(void)
+{
+	/* Blocking includes an implicit local_irq_enable(). */
+	if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)
+		BUG();
+}
+
+static void xen_halt(void)
+{
+	if (irqs_disabled())
+		HYPERVISOR_vcpu_op(VCPUOP_down,
+				   xen_vcpu_nr(smp_processor_id()), NULL);
+	else
+		xen_safe_halt();
+}
+
+static const typeof(pv_ops) xen_irq_ops __initconst = {
+	.irq = {
+		/* Initial interrupt flag handling only called while interrupts off. */
+		.save_fl = __PV_IS_CALLEE_SAVE(paravirt_ret0),
+		.irq_disable = __PV_IS_CALLEE_SAVE(paravirt_nop),
+		.irq_enable = __PV_IS_CALLEE_SAVE(paravirt_BUG),
+
+		.safe_halt = xen_safe_halt,
+		.halt = xen_halt,
+	},
+};
+
+void __init xen_init_irq_ops(void)
+{
+	pv_ops.irq = xen_irq_ops.irq;
+	x86_init.irqs.intr_init = xen_init_IRQ;
+}