xref: /openbmc/linux/arch/x86/xen/irq.c (revision 10a09940)
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  */
xen_force_evtchn_callback(void)22 noinstr void xen_force_evtchn_callback(void)
23 {
24 	(void)HYPERVISOR_xen_version(0, NULL);
25 }
26 
xen_safe_halt(void)27 static 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 
xen_halt(void)34 static 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 
43 static 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(paravirt_BUG),
49 
50 		.safe_halt = xen_safe_halt,
51 		.halt = xen_halt,
52 	},
53 };
54 
xen_init_irq_ops(void)55 void __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