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 
__kvm_timer_set_cntvoff(u32 cntvoff_low,u32 cntvoff_high)24 void __hyp_text __kvm_timer_set_cntvoff(u32 cntvoff_low, u32 cntvoff_high)
25 {
26 	u64 cntvoff = (u64)cntvoff_high << 32 | cntvoff_low;
27 	write_sysreg(cntvoff, cntvoff_el2);
28 }
29 
30 /*
31  * Should only be called on non-VHE systems.
32  * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
33  */
__timer_disable_traps(struct kvm_vcpu * vcpu)34 void __hyp_text __timer_disable_traps(struct kvm_vcpu *vcpu)
35 {
36 	u64 val;
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 
44 /*
45  * Should only be called on non-VHE systems.
46  * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
47  */
__timer_enable_traps(struct kvm_vcpu * vcpu)48 void __hyp_text __timer_enable_traps(struct kvm_vcpu *vcpu)
49 {
50 	u64 val;
51 
52 	/*
53 	 * Disallow physical timer access for the guest
54 	 * Physical counter access is allowed
55 	 */
56 	val = read_sysreg(cnthctl_el2);
57 	val &= ~CNTHCTL_EL1PCEN;
58 	val |= CNTHCTL_EL1PCTEN;
59 	write_sysreg(val, cnthctl_el2);
60 }
61