1// SPDX-License-Identifier: GPL-2.0
2#include <linux/hardirq.h>
3
4#include <asm/x86_init.h>
5
6#include <xen/interface/xen.h>
7#include <xen/interface/sched.h>
8#include <xen/interface/vcpu.h>
9#include <xen/features.h>
10#include <xen/events.h>
11
12#include <asm/xen/hypercall.h>
13#include <asm/xen/hypervisor.h>
14
15#include "xen-ops.h"
16
17/*
18 * Force a proper event-channel callback from Xen after clearing the
19 * callback mask. We do this in a very simple manner, by making a call
20 * down into Xen. The pending flag will be checked by Xen on return.
21 */
22noinstr void xen_force_evtchn_callback(void)
23{
24	(void)HYPERVISOR_xen_version(0, NULL);
25}
26
27static noinstr void xen_safe_halt(void)
28{
29	/* Blocking includes an implicit local_irq_enable(). */
30	if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)
31		BUG();
32}
33
34static void xen_halt(void)
35{
36	if (irqs_disabled())
37		HYPERVISOR_vcpu_op(VCPUOP_down,
38				   xen_vcpu_nr(smp_processor_id()), NULL);
39	else
40		xen_safe_halt();
41}
42
43static const typeof(pv_ops) xen_irq_ops __initconst = {
44	.irq = {
45		/* Initial interrupt flag handling only called while interrupts off. */
46		.save_fl = __PV_IS_CALLEE_SAVE(paravirt_ret0),
47		.irq_disable = __PV_IS_CALLEE_SAVE(paravirt_nop),
48		.irq_enable = __PV_IS_CALLEE_SAVE(BUG_func),
49
50		.safe_halt = xen_safe_halt,
51		.halt = xen_halt,
52	},
53};
54
55void __init xen_init_irq_ops(void)
56{
57	pv_ops.irq = xen_irq_ops.irq;
58	x86_init.irqs.intr_init = xen_init_IRQ;
59}
60