2 * Copyright (C) 2012-2015 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 #include <clocksource/arm_arch_timer.h>
19 #include <linux/compiler.h>
20 #include <linux/kvm_host.h>
22 #include <asm/kvm_hyp.h>
24 /* vcpu is already in the HYP VA space */
25 void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu)
27 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
31 timer->cntv_ctl = read_sysreg_el0(cntv_ctl);
32 timer->cntv_cval = read_sysreg_el0(cntv_cval);
35 /* Disable the virtual timer */
36 write_sysreg_el0(0, cntv_ctl);
39 * We don't need to do this for VHE since the host kernel runs in EL2
40 * with HCR_EL2.TGE ==1, which makes those bits have no impact.
43 /* Allow physical timer/counter access for the host */
44 val = read_sysreg(cnthctl_el2);
45 val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
46 write_sysreg(val, cnthctl_el2);
49 /* Clear cntvoff for the host */
50 write_sysreg(0, cntvoff_el2);
53 void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu)
55 struct kvm *kvm = kern_hyp_va(vcpu->kvm);
56 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
59 /* Those bits are already configured at boot on VHE-system */
62 * Disallow physical timer access for the guest
63 * Physical counter access is allowed
65 val = read_sysreg(cnthctl_el2);
66 val &= ~CNTHCTL_EL1PCEN;
67 val |= CNTHCTL_EL1PCTEN;
68 write_sysreg(val, cnthctl_el2);
72 write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2);
73 write_sysreg_el0(timer->cntv_cval, cntv_cval);
75 write_sysreg_el0(timer->cntv_ctl, cntv_ctl);