arch/x86/xen/irq.c

   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  */
  22 noinstr void xen_force_evtchn_callback(void)
  23 {
  24         (void)HYPERVISOR_xen_version(0, NULL);
  25 }
  26
  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
  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(BUG_func),
  49
  50                 .safe_halt = xen_safe_halt,
  51                 .halt = xen_halt,
  52         },
  53 };
  54
  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 }