timer-sr.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012-2015 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 */
 
#include <clocksource/arm_arch_timer.h>
#include <linux/compiler.h>
#include <linux/kvm_host.h>
 
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
 
void __kvm_timer_set_cntvoff(u64 cntvoff)
{
    write_sysreg(cntvoff, cntvoff_el2);
}
 
/*
 * Should only be called on non-VHE or hVHE setups.
 * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
 */
void __timer_disable_traps(struct kvm_vcpu *vcpu)
{
    u64 val, shift = 0;
 
    if (has_hvhe())
        shift = 10;
 
    /* Allow physical timer/counter access for the host */
    val = read_sysreg(cnthctl_el2);
    val |= (CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN) << shift;
    write_sysreg(val, cnthctl_el2);
}
 
/*
 * Should only be called on non-VHE or hVHE setups.
 * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
 */
void __timer_enable_traps(struct kvm_vcpu *vcpu)
{
    u64 clr = 0, set = 0;
 
    /*
     * Disallow physical timer access for the guest
     * Physical counter access is allowed if no offset is enforced
     * or running protected (we don't offset anything in this case).
     */
    clr = CNTHCTL_EL1PCEN;
    if (is_protected_kvm_enabled() ||
        !kern_hyp_va(vcpu->kvm)->arch.timer_data.poffset)
        set |= CNTHCTL_EL1PCTEN;
    else
        clr |= CNTHCTL_EL1PCTEN;
 
    if (has_hvhe()) {
        clr <<= 10;
        set <<= 10;
    }
 
    sysreg_clear_set(cnthctl_el2, clr, set);
}