linux-sg2042/virt/kvm/arm/hyp/timer-sr.c

69 lines
1.9 KiB
C

/*
* Copyright (C) 2012-2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <clocksource/arm_arch_timer.h>
#include <linux/compiler.h>
#include <linux/kvm_host.h>
#include <asm/kvm_hyp.h>
/* vcpu is already in the HYP VA space */
void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
u64 val;
if (timer->enabled) {
timer->cntv_ctl = read_sysreg_el0(cntv_ctl);
timer->cntv_cval = read_sysreg_el0(cntv_cval);
}
/* Disable the virtual timer */
write_sysreg_el0(0, cntv_ctl);
/* Allow physical timer/counter access for the host */
val = read_sysreg(cnthctl_el2);
val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
write_sysreg(val, cnthctl_el2);
/* Clear cntvoff for the host */
write_sysreg(0, cntvoff_el2);
}
void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = kern_hyp_va(vcpu->kvm);
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
u64 val;
/*
* Disallow physical timer access for the guest
* Physical counter access is allowed
*/
val = read_sysreg(cnthctl_el2);
val &= ~CNTHCTL_EL1PCEN;
val |= CNTHCTL_EL1PCTEN;
write_sysreg(val, cnthctl_el2);
if (timer->enabled) {
write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2);
write_sysreg_el0(timer->cntv_cval, cntv_cval);
isb();
write_sysreg_el0(timer->cntv_ctl, cntv_ctl);
}
}