Merge tag 'riscv-for-linus-5.20-mw2' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-2.6-microblaze.git] / arch / riscv / kvm / vcpu_timer.c

diff --git a/arch/riscv/kvm/vcpu_timer.c b/arch/riscv/kvm/vcpu_timer.c
index 5950438..16f50c4 100644 (file)
--- a/arch/riscv/kvm/vcpu_timer.c
+++ b/arch/riscv/kvm/vcpu_timer.c
@@ -69,7 +69,18 @@ static int kvm_riscv_vcpu_timer_cancel(struct kvm_vcpu_timer *t)
        return 0;
 }
 
-int kvm_riscv_vcpu_timer_next_event(struct kvm_vcpu *vcpu, u64 ncycles)
+static int kvm_riscv_vcpu_update_vstimecmp(struct kvm_vcpu *vcpu, u64 ncycles)
+{
+#if defined(CONFIG_32BIT)
+               csr_write(CSR_VSTIMECMP, ncycles & 0xFFFFFFFF);
+               csr_write(CSR_VSTIMECMPH, ncycles >> 32);
+#else
+               csr_write(CSR_VSTIMECMP, ncycles);
+#endif
+               return 0;
+}
+
+static int kvm_riscv_vcpu_update_hrtimer(struct kvm_vcpu *vcpu, u64 ncycles)
 {
        struct kvm_vcpu_timer *t = &vcpu->arch.timer;
        struct kvm_guest_timer *gt = &vcpu->kvm->arch.timer;
@@ -88,6 +99,65 @@ int kvm_riscv_vcpu_timer_next_event(struct kvm_vcpu *vcpu, u64 ncycles)
        return 0;
 }
 
+int kvm_riscv_vcpu_timer_next_event(struct kvm_vcpu *vcpu, u64 ncycles)
+{
+       struct kvm_vcpu_timer *t = &vcpu->arch.timer;
+
+       return t->timer_next_event(vcpu, ncycles);
+}
+
+static enum hrtimer_restart kvm_riscv_vcpu_vstimer_expired(struct hrtimer *h)
+{
+       u64 delta_ns;
+       struct kvm_vcpu_timer *t = container_of(h, struct kvm_vcpu_timer, hrt);
+       struct kvm_vcpu *vcpu = container_of(t, struct kvm_vcpu, arch.timer);
+       struct kvm_guest_timer *gt = &vcpu->kvm->arch.timer;
+
+       if (kvm_riscv_current_cycles(gt) < t->next_cycles) {
+               delta_ns = kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t);
+               hrtimer_forward_now(&t->hrt, ktime_set(0, delta_ns));
+               return HRTIMER_RESTART;
+       }
+
+       t->next_set = false;
+       kvm_vcpu_kick(vcpu);
+
+       return HRTIMER_NORESTART;
+}
+
+bool kvm_riscv_vcpu_timer_pending(struct kvm_vcpu *vcpu)
+{
+       struct kvm_vcpu_timer *t = &vcpu->arch.timer;
+       struct kvm_guest_timer *gt = &vcpu->kvm->arch.timer;
+
+       if (!kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t) ||
+           kvm_riscv_vcpu_has_interrupts(vcpu, 1UL << IRQ_VS_TIMER))
+               return true;
+       else
+               return false;
+}
+
+static void kvm_riscv_vcpu_timer_blocking(struct kvm_vcpu *vcpu)
+{
+       struct kvm_vcpu_timer *t = &vcpu->arch.timer;
+       struct kvm_guest_timer *gt = &vcpu->kvm->arch.timer;
+       u64 delta_ns;
+
+       if (!t->init_done)
+               return;
+
+       delta_ns = kvm_riscv_delta_cycles2ns(t->next_cycles, gt, t);
+       if (delta_ns) {
+               hrtimer_start(&t->hrt, ktime_set(0, delta_ns), HRTIMER_MODE_REL);
+               t->next_set = true;
+       }
+}
+
+static void kvm_riscv_vcpu_timer_unblocking(struct kvm_vcpu *vcpu)
+{
+       kvm_riscv_vcpu_timer_cancel(&vcpu->arch.timer);
+}
+
 int kvm_riscv_vcpu_get_reg_timer(struct kvm_vcpu *vcpu,
                                 const struct kvm_one_reg *reg)
 {
@@ -180,10 +250,20 @@ int kvm_riscv_vcpu_timer_init(struct kvm_vcpu *vcpu)
                return -EINVAL;
 
        hrtimer_init(&t->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-       t->hrt.function = kvm_riscv_vcpu_hrtimer_expired;
        t->init_done = true;
        t->next_set = false;
 
+       /* Enable sstc for every vcpu if available in hardware */
+       if (riscv_isa_extension_available(NULL, SSTC)) {
+               t->sstc_enabled = true;
+               t->hrt.function = kvm_riscv_vcpu_vstimer_expired;
+               t->timer_next_event = kvm_riscv_vcpu_update_vstimecmp;
+       } else {
+               t->sstc_enabled = false;
+               t->hrt.function = kvm_riscv_vcpu_hrtimer_expired;
+               t->timer_next_event = kvm_riscv_vcpu_update_hrtimer;
+       }
+
        return 0;
 }
 
@@ -199,21 +279,73 @@ int kvm_riscv_vcpu_timer_deinit(struct kvm_vcpu *vcpu)
 
 int kvm_riscv_vcpu_timer_reset(struct kvm_vcpu *vcpu)
 {
+       struct kvm_vcpu_timer *t = &vcpu->arch.timer;
+
+       t->next_cycles = -1ULL;
        return kvm_riscv_vcpu_timer_cancel(&vcpu->arch.timer);
 }
 
-void kvm_riscv_vcpu_timer_restore(struct kvm_vcpu *vcpu)
+static void kvm_riscv_vcpu_update_timedelta(struct kvm_vcpu *vcpu)
 {
        struct kvm_guest_timer *gt = &vcpu->kvm->arch.timer;
 
-#ifdef CONFIG_64BIT
-       csr_write(CSR_HTIMEDELTA, gt->time_delta);
-#else
+#if defined(CONFIG_32BIT)
        csr_write(CSR_HTIMEDELTA, (u32)(gt->time_delta));
        csr_write(CSR_HTIMEDELTAH, (u32)(gt->time_delta >> 32));
+#else
+       csr_write(CSR_HTIMEDELTA, gt->time_delta);
 #endif
 }
 
+void kvm_riscv_vcpu_timer_restore(struct kvm_vcpu *vcpu)
+{
+       struct kvm_vcpu_csr *csr;
+       struct kvm_vcpu_timer *t = &vcpu->arch.timer;
+
+       kvm_riscv_vcpu_update_timedelta(vcpu);
+
+       if (!t->sstc_enabled)
+               return;
+
+       csr = &vcpu->arch.guest_csr;
+#if defined(CONFIG_32BIT)
+       csr_write(CSR_VSTIMECMP, (u32)t->next_cycles);
+       csr_write(CSR_VSTIMECMPH, (u32)(t->next_cycles >> 32));
+#else
+       csr_write(CSR_VSTIMECMP, t->next_cycles);
+#endif
+
+       /* timer should be enabled for the remaining operations */
+       if (unlikely(!t->init_done))
+               return;
+
+       kvm_riscv_vcpu_timer_unblocking(vcpu);
+}
+
+void kvm_riscv_vcpu_timer_save(struct kvm_vcpu *vcpu)
+{
+       struct kvm_vcpu_csr *csr;
+       struct kvm_vcpu_timer *t = &vcpu->arch.timer;
+
+       if (!t->sstc_enabled)
+               return;
+
+       csr = &vcpu->arch.guest_csr;
+       t = &vcpu->arch.timer;
+#if defined(CONFIG_32BIT)
+       t->next_cycles = csr_read(CSR_VSTIMECMP);
+       t->next_cycles |= (u64)csr_read(CSR_VSTIMECMPH) << 32;
+#else
+       t->next_cycles = csr_read(CSR_VSTIMECMP);
+#endif
+       /* timer should be enabled for the remaining operations */
+       if (unlikely(!t->init_done))
+               return;
+
+       if (kvm_vcpu_is_blocking(vcpu))
+               kvm_riscv_vcpu_timer_blocking(vcpu);
+}
+
 void kvm_riscv_guest_timer_init(struct kvm *kvm)
 {
        struct kvm_guest_timer *gt = &kvm->arch.timer;