timer-sr.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2012-2015 - ARM Ltd
 4 * Author: Marc Zyngier <marc.zyngier@arm.com>
 5 */
 6
 7#include <clocksource/arm_arch_timer.h>
 8#include <linux/compiler.h>
 9#include <linux/kvm_host.h>
10
11#include <asm/kvm_hyp.h>
12#include <asm/kvm_mmu.h>
13
14void __kvm_timer_set_cntvoff(u64 cntvoff)
15{
16	write_sysreg(cntvoff, cntvoff_el2);
17}
18
19/*
20 * Should only be called on non-VHE or hVHE setups.
21 * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
22 */
23void __timer_disable_traps(struct kvm_vcpu *vcpu)
24{
25	u64 set, clr, shift = 0;
26
27	if (has_hvhe())
28		shift = 10;
29
30	/* Allow physical timer/counter access for the host */
31	set = (CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN) << shift;
32	clr = CNTHCTL_EL1TVT | CNTHCTL_EL1TVCT;
33
34	sysreg_clear_set(cnthctl_el2, clr, set);
35}
36
37/*
38 * Should only be called on non-VHE or hVHE setups.
39 * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
40 */
41void __timer_enable_traps(struct kvm_vcpu *vcpu)
42{
43	u64 clr = 0, set = 0;
44
45	/*
46	 * Disallow physical timer access for the guest
47	 * Physical counter access is allowed if no offset is enforced
48	 * or running protected (we don't offset anything in this case).
49	 */
50	clr = CNTHCTL_EL1PCEN;
51	if (is_protected_kvm_enabled() ||
52	    !kern_hyp_va(vcpu->kvm)->arch.timer_data.poffset)
53		set |= CNTHCTL_EL1PCTEN;
54	else
55		clr |= CNTHCTL_EL1PCTEN;
56
57	if (has_hvhe()) {
58		clr <<= 10;
59		set <<= 10;
60	}
61
62	/*
63	 * Trap the virtual counter/timer if we have a broken cntvoff
64	 * implementation.
65	 */
66	if (has_broken_cntvoff())
67		set |= CNTHCTL_EL1TVT | CNTHCTL_EL1TVCT;
68
69	sysreg_clear_set(cnthctl_el2, clr, set);
70}