KVM: PPC: Remove the tasklet used by the hrtimer

Powerpc timer implementation is a copycat version of s390. Now that they removed
the tasklet with commit ea74c0ea1b24a6978a6ebc80ba4dbc7b7848b32d follow this
optimization.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/include/asm/kvm_host.h

@@ -606,7 +606,6 @@ struct kvm_vcpu_arch {
 	u32 cpr0_cfgaddr; /* holds the last set cpr0_cfgaddr */
 
 	struct hrtimer dec_timer;
-	struct tasklet_struct tasklet;
 	u64 dec_jiffies;
 	u64 dec_expires;
 	unsigned long pending_exceptions;

arch/powerpc/include/asm/kvm_ppc.h

@@ -89,7 +89,7 @@ extern int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu);
 extern int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu);
 extern void kvmppc_emulate_dec(struct kvm_vcpu *vcpu);
 extern u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb);
-extern void kvmppc_decrementer_func(unsigned long data);
+extern void kvmppc_decrementer_func(struct kvm_vcpu *vcpu);
 extern int kvmppc_sanity_check(struct kvm_vcpu *vcpu);
 extern int kvmppc_subarch_vcpu_init(struct kvm_vcpu *vcpu);
 extern void kvmppc_subarch_vcpu_uninit(struct kvm_vcpu *vcpu);

arch/powerpc/kvm/book3s.c

@@ -718,10 +718,8 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 	return -EINVAL;
 }
 
-void kvmppc_decrementer_func(unsigned long data)
+void kvmppc_decrementer_func(struct kvm_vcpu *vcpu)
 {
-	struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
-
 	kvmppc_core_queue_dec(vcpu);
 	kvm_vcpu_kick(vcpu);
 }

arch/powerpc/kvm/booke.c

@@ -1822,10 +1822,8 @@ void kvmppc_clr_tsr_bits(struct kvm_vcpu *vcpu, u32 tsr_bits)
 	update_timer_ints(vcpu);
 }
 
-void kvmppc_decrementer_func(unsigned long data)
+void kvmppc_decrementer_func(struct kvm_vcpu *vcpu)
 {
-	struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
-
 	if (vcpu->arch.tcr & TCR_ARE) {
 		vcpu->arch.dec = vcpu->arch.decar;
 		kvmppc_emulate_dec(vcpu);

arch/powerpc/kvm/powerpc.c

@@ -638,7 +638,6 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
 {
 	/* Make sure we're not using the vcpu anymore */
 	hrtimer_cancel(&vcpu->arch.dec_timer);
-	tasklet_kill(&vcpu->arch.tasklet);
 
 	kvmppc_remove_vcpu_debugfs(vcpu);
 
@@ -664,16 +663,12 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 	return kvmppc_core_pending_dec(vcpu);
 }
 
-/*
- * low level hrtimer wake routine. Because this runs in hardirq context
- * we schedule a tasklet to do the real work.
- */
 enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer)
 {
 	struct kvm_vcpu *vcpu;
 
 	vcpu = container_of(timer, struct kvm_vcpu, arch.dec_timer);
-	tasklet_schedule(&vcpu->arch.tasklet);
+	kvmppc_decrementer_func(vcpu);
 
 	return HRTIMER_NORESTART;
 }
@@ -683,7 +678,6 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 	int ret;
 
 	hrtimer_init(&vcpu->arch.dec_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
-	tasklet_init(&vcpu->arch.tasklet, kvmppc_decrementer_func, (ulong)vcpu);
 	vcpu->arch.dec_timer.function = kvmppc_decrementer_wakeup;
 	vcpu->arch.dec_expires = ~(u64)0;