mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
110 lines
2.6 KiB
110 lines
2.6 KiB
// 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. |
|
*/ |
|
void xen_force_evtchn_callback(void) |
|
{ |
|
(void)HYPERVISOR_xen_version(0, NULL); |
|
} |
|
|
|
asmlinkage __visible unsigned long xen_save_fl(void) |
|
{ |
|
struct vcpu_info *vcpu; |
|
unsigned long flags; |
|
|
|
vcpu = this_cpu_read(xen_vcpu); |
|
|
|
/* flag has opposite sense of mask */ |
|
flags = !vcpu->evtchn_upcall_mask; |
|
|
|
/* convert to IF type flag |
|
-0 -> 0x00000000 |
|
-1 -> 0xffffffff |
|
*/ |
|
return (-flags) & X86_EFLAGS_IF; |
|
} |
|
PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl); |
|
|
|
asmlinkage __visible void xen_irq_disable(void) |
|
{ |
|
/* There's a one instruction preempt window here. We need to |
|
make sure we're don't switch CPUs between getting the vcpu |
|
pointer and updating the mask. */ |
|
preempt_disable(); |
|
this_cpu_read(xen_vcpu)->evtchn_upcall_mask = 1; |
|
preempt_enable_no_resched(); |
|
} |
|
PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable); |
|
|
|
asmlinkage __visible void xen_irq_enable(void) |
|
{ |
|
struct vcpu_info *vcpu; |
|
|
|
/* |
|
* We may be preempted as soon as vcpu->evtchn_upcall_mask is |
|
* cleared, so disable preemption to ensure we check for |
|
* events on the VCPU we are still running on. |
|
*/ |
|
preempt_disable(); |
|
|
|
vcpu = this_cpu_read(xen_vcpu); |
|
vcpu->evtchn_upcall_mask = 0; |
|
|
|
/* Doesn't matter if we get preempted here, because any |
|
pending event will get dealt with anyway. */ |
|
|
|
barrier(); /* unmask then check (avoid races) */ |
|
if (unlikely(vcpu->evtchn_upcall_pending)) |
|
xen_force_evtchn_callback(); |
|
|
|
preempt_enable(); |
|
} |
|
PV_CALLEE_SAVE_REGS_THUNK(xen_irq_enable); |
|
|
|
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 struct pv_irq_ops xen_irq_ops __initconst = { |
|
.save_fl = PV_CALLEE_SAVE(xen_save_fl), |
|
.irq_disable = PV_CALLEE_SAVE(xen_irq_disable), |
|
.irq_enable = PV_CALLEE_SAVE(xen_irq_enable), |
|
|
|
.safe_halt = xen_safe_halt, |
|
.halt = xen_halt, |
|
}; |
|
|
|
void __init xen_init_irq_ops(void) |
|
{ |
|
pv_ops.irq = xen_irq_ops; |
|
x86_init.irqs.intr_init = xen_init_IRQ; |
|
}
|
|
|