/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* KVM/MIPS: Interrupt delivery
*
* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
* Authors: Sanjay Lal <sanjayl@kymasys.com>
*/
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/bootmem.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <linux/kvm_host.h>
#include "interrupt.h"
void kvm_mips_queue_irq(struct kvm_vcpu *vcpu, uint32_t priority)
{
set_bit(priority, &vcpu->arch.pending_exceptions);
}
void kvm_mips_dequeue_irq(struct kvm_vcpu *vcpu, uint32_t priority)
{
clear_bit(priority, &vcpu->arch.pending_exceptions);
}
void kvm_mips_queue_timer_int_cb(struct kvm_vcpu *vcpu)
{
/*
* Cause bits to reflect the pending timer interrupt,
* the EXC code will be set when we are actually
* delivering the interrupt:
*/
kvm_set_c0_guest_cause(vcpu->arch.cop0, (C_IRQ5 | C_TI));
/* Queue up an INT exception for the core */
kvm_mips_queue_irq(vcpu, MIPS_EXC_INT_TIMER);
}
void kvm_mips_dequeue_timer_int_cb(struct kvm_vcpu *vcpu)
{
kvm_clear_c0_guest_cause(vcpu->arch.cop0, (C_IRQ5 | C_TI));
kvm_mips_dequeue_irq(vcpu, MIPS_EXC_INT_TIMER);
}
void kvm_mips_queue_io_int_cb(struct kvm_vcpu *vcpu,
struct kvm_mips_interrupt *irq)
{
int intr = (int)irq->irq;
/*
* Cause bits to reflect the pending IO interrupt,
* the EXC code will be set when we are actually
* delivering the interrupt:
*/
switch (intr) {
case 2:
kvm_set_c0_guest_cause(vcpu->arch.cop0, (C_IRQ0));
/* Queue up an INT exception for the core */
kvm_mips_queue_irq(vcpu, MIPS_EXC_INT_IO);
break;
case 3:
kvm_set_c0_guest_cause(vcpu->arch.cop0, (C_IRQ1));
kvm_mips_queue_irq(vcpu, MIPS_EXC_INT_IPI_1);
break;
case 4:
kvm_set_c0_guest_cause(vcpu->arch.cop0, (C_IRQ2));
kvm_mips_queue_irq(vcpu, MIPS_EXC_INT_IPI_2);
break;
default:
break;
}
}
void kvm_mips_dequeue_io_int_cb(struct kvm_vcpu *vcpu,
struct kvm_mips_interrupt *irq)
{
int intr = (int)irq->irq;
switch (intr) {
case -2:
kvm_clear_c0_guest_cause(vcpu->arch.cop0, (C_IRQ0));
kvm_mips_dequeue_irq(vcpu, MIPS_EXC_INT_IO);
break;
case -3:
kvm_clear_c0_guest_cause(vcpu->arch.cop0, (C_IRQ1));
kvm_mips_dequeue_irq(vcpu, MIPS_EXC_INT_IPI_1);
break;
case -4:
kvm_clear_c0_guest_cause(vcpu->arch.cop0, (C_IRQ2));
kvm_mips_dequeue_irq(vcpu, MIPS_EXC_INT_IPI_2);
break;
default:
break;
}
}
/* Deliver the interrupt of the corresponding priority, if possible. */
int kvm_mips_irq_deliver_cb(struct kvm_vcpu *vcpu, unsigned int priority,
uint32_t cause)
{
int allowed = 0;
uint32_t exccode;
struct kvm_vcpu_arch *arch = &vcpu->arch;
struct mips_coproc *cop0 = vcpu->arch.cop0;
switch (priority) {
case MIPS_EXC_INT_TIMER:
if ((kvm_read_c0_guest_status(cop0) & ST0_IE)
&& (!(kvm_read_c0_guest_status(cop0) & (ST0_EXL | ST0_ERL)))
&& (kvm_read_c0_guest_status(cop0) & IE_IRQ5)) {
allowed = 1;
exccode = T_INT;
}
break;
case MIPS_EXC_INT_IO:
if ((kvm_read_c0_guest_status(cop0) & ST0_IE)
&& (!(kvm_read_c0_guest_status(cop0) & (ST0_EXL | ST0_ERL)))
&& (kvm_read_c0_guest_status(cop0) & IE_IRQ0)) {
allowed = 1;
exccode = T_INT;
}
break;
case MIPS_EXC_INT_IPI_1:
if ((kvm_read_c0_guest_status(cop0) & ST0_IE)
&& (!(kvm_read_c0_guest_status(cop0) & (ST0_EXL | ST0_ERL)))
&& (kvm_read_c0_guest_status(cop0) & IE_IRQ1)) {
allowed = 1;
exccode = T_INT;
}
break;
case MIPS_EXC_INT_IPI_2:
if ((kvm_read_c0_guest_status(cop0) & ST0_IE)
&& (!(kvm_read_c0_guest_status(cop0) & (ST0_EXL | ST0_ERL)))
&& (kvm_read_c0_guest_status(cop0) & IE_IRQ2)) {
allowed = 1;
exccode = T_INT;
}
break;
default:
break;
}
/* Are we allowed to deliver the interrupt ??? */
if (allowed) {
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
kvm_write_c0_guest_epc(cop0, arch->pc);
kvm_set_c0_guest_status(cop0, ST0_EXL);
if (cause & CAUSEF_BD)
kvm_set_c0_guest_cause(cop0, CAUSEF_BD);
else
kvm_clear_c0_guest_cause(cop0, CAUSEF_BD);
kvm_debug("Delivering INT @ pc %#lx\n", arch->pc);
} else
kvm_err("Trying to deliver interrupt when EXL is already set\n");
kvm_change_c0_guest_cause(cop0, CAUSEF_EXCCODE,
(exccode << CAUSEB_EXCCODE));
/* XXXSL Set PC to the interrupt exception entry point */
if (kvm_read_c0_guest_cause(cop0) & CAUSEF_IV)
arch->pc = KVM_GUEST_KSEG0 + 0x200;
else
arch->pc = KVM_GUEST_KSEG0 + 0x180;
clear_bit(priority, &vcpu->arch.pending_exceptions);
}
return allowed;
}
int kvm_mips_irq_clear_cb(struct kvm_vcpu *vcpu, unsigned int priority,
uint32_t cause)
{
return 1;
}
void kvm_mips_deliver_interrupts(struct kvm_vcpu *vcpu, uint32_t cause)
{
unsigned long *pending = &vcpu->arch.pending_exceptions;
unsigned long *pending_clr = &vcpu->arch.pending_exceptions_clr;
unsigned int priority;
if (!(*pending) && !(*pending_clr))
return;
priority = __ffs(*pending_clr);
while (priority <= MIPS_EXC_MAX) {
if (kvm_mips_callbacks->irq_clear(vcpu, priority, cause)) {
if (!KVM_MIPS_IRQ_CLEAR_ALL_AT_ONCE)
break;
}
priority = find_next_bit(pending_clr,
BITS_PER_BYTE * sizeof(*pending_clr),
priority + 1);
}
priority = __ffs(*pending);
while (priority <= MIPS_EXC_MAX) {
if (kvm_mips_callbacks->irq_deliver(vcpu, priority, cause)) {
if (!KVM_MIPS_IRQ_DELIVER_ALL_AT_ONCE)
break;
}
priority = find_next_bit(pending,
BITS_PER_BYTE * sizeof(*pending),
priority + 1);
}
}
int kvm_mips_pending_timer(struct kvm_vcpu *vcpu)
{
return test_bit(MIPS_EXC_INT_TIMER, &vcpu->arch.pending_exceptions);
}
