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(cmd: 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 vcpuid: 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

source code of linux/arch/x86/xen/irq.c