virt/kvm/arm/hyp/timer-sr.c

   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 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 void __hyp_text __timer_disable_traps(struct kvm_vcpu *vcpu)
  31 {
  32         /*
  33          * We don't need to do this for VHE since the host kernel runs in EL2
  34          * with HCR_EL2.TGE ==1, which makes those bits have no impact.
  35          */
  36         if (!has_vhe()) {
  37                 u64 val;
  38
  39                 /* Allow physical timer/counter access for the host */
  40                 val = read_sysreg(cnthctl_el2);
  41                 val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
  42                 write_sysreg(val, cnthctl_el2);
  43         }
  44 }
  45
  46 void __hyp_text __timer_enable_traps(struct kvm_vcpu *vcpu)
  47 {
  48         if (!has_vhe()) {
  49                 u64 val;
  50
  51                 /*
  52                  * Disallow physical timer access for the guest
  53                  * Physical counter access is allowed
  54                  */
  55                 val = read_sysreg(cnthctl_el2);
  56                 val &= ~CNTHCTL_EL1PCEN;
  57                 val |= CNTHCTL_EL1PCTEN;
  58                 write_sysreg(val, cnthctl_el2);
  59         }
  60 }