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/*
* 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;
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
u64 val;
if (timer->enabled) {
vtimer->cnt_ctl = read_sysreg_el0(cntv_ctl);
vtimer->cnt_cval = read_sysreg_el0(cntv_cval);
}
/* Disable the virtual timer */
write_sysreg_el0(0, cntv_ctl);
/*
* We don't need to do this for VHE since the host kernel runs in EL2
* with HCR_EL2.TGE ==1, which makes those bits have no impact.
*/
if (!has_vhe()) {
/* 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 arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
u64 val;
/* Those bits are already configured at boot on VHE-system */
if (!has_vhe()) {
/*
* 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(vtimer->cntvoff, cntvoff_el2);
write_sysreg_el0(vtimer->cnt_cval, cntv_cval);
isb();
write_sysreg_el0(vtimer->cnt_ctl, cntv_ctl);
}
}
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