1 /* 2 * Copyright (C) 2012-2015 - ARM Ltd 3 * Author: Marc Zyngier <marc.zyngier@arm.com> 4 * 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. 8 * 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. 13 * 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/>. 16 */ 17 18 #include <clocksource/arm_arch_timer.h> 19 #include <linux/compiler.h> 20 #include <linux/kvm_host.h> 21 22 #include <asm/kvm_hyp.h> 23 24 /* vcpu is already in the HYP VA space */ __timer_save_state(struct kvm_vcpu * vcpu)25void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu) 26 { 27 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; 28 u64 val; 29 30 if (timer->enabled) { 31 timer->cntv_ctl = read_sysreg_el0(cntv_ctl); 32 timer->cntv_cval = read_sysreg_el0(cntv_cval); 33 } 34 35 /* Disable the virtual timer */ 36 write_sysreg_el0(0, cntv_ctl); 37 38 /* Allow physical timer/counter access for the host */ 39 val = read_sysreg(cnthctl_el2); 40 val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN; 41 write_sysreg(val, cnthctl_el2); 42 43 /* Clear cntvoff for the host */ 44 write_sysreg(0, cntvoff_el2); 45 } 46 __timer_restore_state(struct kvm_vcpu * vcpu)47void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu) 48 { 49 struct kvm *kvm = kern_hyp_va(vcpu->kvm); 50 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; 51 u64 val; 52 53 /* 54 * Disallow physical timer access for the guest 55 * Physical counter access is allowed 56 */ 57 val = read_sysreg(cnthctl_el2); 58 val &= ~CNTHCTL_EL1PCEN; 59 val |= CNTHCTL_EL1PCTEN; 60 write_sysreg(val, cnthctl_el2); 61 62 if (timer->enabled) { 63 write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2); 64 write_sysreg_el0(timer->cntv_cval, cntv_cval); 65 isb(); 66 write_sysreg_el0(timer->cntv_ctl, cntv_ctl); 67 } 68 } 69