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authorAlex Shi <alex.shi@linaro.org>2016-05-24 12:02:26 +0800
committerAlex Shi <alex.shi@linaro.org>2016-05-24 16:30:24 +0800
commit4159c94b206b5c74b0ba4c626eeee9db8ec55559 (patch)
tree685f7518bf3e753a8320987137207c6c7ca89323
parentd4b8d850577b71af7ca6f46debc9c9feef6c13d2 (diff)
downloadlinux-linaro-stable-4159c94b206b5c74b0ba4c626eeee9db8ec55559.tar.gz
arm64: KVM: Implement timer save/restore
Implement the timer save restore as a direct translation of the assembly code version. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> (cherry picked from commit 1431af367e52b08038e78d346822966d968f1694) Signed-off-by: Alex Shi <alex.shi@linaro.org> Conflicts: arch/arm64/kvm/hyp/Makefile arch/arm64/kvm/hyp/hyp.h
-rw-r--r--arch/arm64/kvm/hyp/Makefile1
-rw-r--r--arch/arm64/kvm/hyp/hyp.h3
-rw-r--r--arch/arm64/kvm/hyp/timer-sr.c71
-rw-r--r--include/clocksource/arm_arch_timer.h6
4 files changed, 81 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index d8d5968fbbed..1c15105bce50 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -3,3 +3,4 @@
#
obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o
+obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o
diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h
index ac63553834b9..7d58089da256 100644
--- a/arch/arm64/kvm/hyp/hyp.h
+++ b/arch/arm64/kvm/hyp/hyp.h
@@ -32,5 +32,8 @@
void __vgic_v2_save_state(struct kvm_vcpu *vcpu);
void __vgic_v2_restore_state(struct kvm_vcpu *vcpu);
+void __timer_save_state(struct kvm_vcpu *vcpu);
+void __timer_restore_state(struct kvm_vcpu *vcpu);
+
#endif /* __ARM64_KVM_HYP_H__ */
diff --git a/arch/arm64/kvm/hyp/timer-sr.c b/arch/arm64/kvm/hyp/timer-sr.c
new file mode 100644
index 000000000000..1051e5d7320f
--- /dev/null
+++ b/arch/arm64/kvm/hyp/timer-sr.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2012-2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <clocksource/arm_arch_timer.h>
+#include <linux/compiler.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_mmu.h>
+
+#include "hyp.h"
+
+/* vcpu is already in the HYP VA space */
+void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = kern_hyp_va(vcpu->kvm);
+ struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ u64 val;
+
+ if (kvm->arch.timer.enabled) {
+ timer->cntv_ctl = read_sysreg(cntv_ctl_el0);
+ timer->cntv_cval = read_sysreg(cntv_cval_el0);
+ }
+
+ /* Disable the virtual timer */
+ write_sysreg(0, cntv_ctl_el0);
+
+ /* Allow physical timer/counter access for the host */
+ val = read_sysreg(cnthctl_el2);
+ val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
+ write_sysreg(val, cnthctl_el2);
+
+ /* Clear cntvoff for the host */
+ write_sysreg(0, cntvoff_el2);
+}
+
+void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = kern_hyp_va(vcpu->kvm);
+ struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+ u64 val;
+
+ /*
+ * Disallow physical timer access for the guest
+ * Physical counter access is allowed
+ */
+ val = read_sysreg(cnthctl_el2);
+ val &= ~CNTHCTL_EL1PCEN;
+ val |= CNTHCTL_EL1PCTEN;
+ write_sysreg(val, cnthctl_el2);
+
+ if (kvm->arch.timer.enabled) {
+ write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2);
+ write_sysreg(timer->cntv_cval, cntv_cval_el0);
+ isb();
+ write_sysreg(timer->cntv_ctl, cntv_ctl_el0);
+ }
+}
diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h
index 9916d0e4eff5..25d0914481a2 100644
--- a/include/clocksource/arm_arch_timer.h
+++ b/include/clocksource/arm_arch_timer.h
@@ -23,6 +23,12 @@
#define ARCH_TIMER_CTRL_IT_MASK (1 << 1)
#define ARCH_TIMER_CTRL_IT_STAT (1 << 2)
+#define CNTHCTL_EL1PCTEN (1 << 0)
+#define CNTHCTL_EL1PCEN (1 << 1)
+#define CNTHCTL_EVNTEN (1 << 2)
+#define CNTHCTL_EVNTDIR (1 << 3)
+#define CNTHCTL_EVNTI (0xF << 4)
+
enum arch_timer_reg {
ARCH_TIMER_REG_CTRL,
ARCH_TIMER_REG_TVAL,