[PATCH 25/39] arm/arm64: KVM: Add smccc accessors to PSCI code

[Alex Shi]

From: Marc Zyngier <marc.zyngier at arm.com>

commit 84684fecd7ea upstream.

Instead of open coding the accesses to the various registers,
let's add explicit SMCCC accessors.

Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas at arm.com>
Signed-off-by: Will Deacon <will.deacon at arm.com>
Signed-off-by: Alex Shi <alex.shi at linaro.org>
---
 arch/arm/kvm/psci.c | 52 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 10 deletions(-)

diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 85fc21b43f6f..946acf69a021 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -33,6 +33,38 @@
 
 #define AFFINITY_MASK(level)	~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)
 
+static u32 smccc_get_function(struct kvm_vcpu *vcpu)
+{
+	return vcpu_get_reg(vcpu, 0);
+}
+
+static unsigned long smccc_get_arg1(struct kvm_vcpu *vcpu)
+{
+	return vcpu_get_reg(vcpu, 1);
+}
+
+static unsigned long smccc_get_arg2(struct kvm_vcpu *vcpu)
+{
+	return vcpu_get_reg(vcpu, 2);
+}
+
+static unsigned long smccc_get_arg3(struct kvm_vcpu *vcpu)
+{
+	return vcpu_get_reg(vcpu, 3);
+}
+
+static void smccc_set_retval(struct kvm_vcpu *vcpu,
+			     unsigned long a0,
+			     unsigned long a1,
+			     unsigned long a2,
+			     unsigned long a3)
+{
+	vcpu_set_reg(vcpu, 0, a0);
+	vcpu_set_reg(vcpu, 1, a1);
+	vcpu_set_reg(vcpu, 2, a2);
+	vcpu_set_reg(vcpu, 3, a3);
+}
+
 static unsigned long psci_affinity_mask(unsigned long affinity_level)
 {
 	if (affinity_level <= 3)
@@ -75,7 +107,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 	unsigned long context_id;
 	phys_addr_t target_pc;
 
-	cpu_id = vcpu_get_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
+	cpu_id = smccc_get_arg1(source_vcpu) & MPIDR_HWID_BITMASK;
 	if (vcpu_mode_is_32bit(source_vcpu))
 		cpu_id &= ~((u32) 0);
 
@@ -94,8 +126,8 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 			return PSCI_RET_INVALID_PARAMS;
 	}
 
-	target_pc = vcpu_get_reg(source_vcpu, 2);
-	context_id = vcpu_get_reg(source_vcpu, 3);
+	target_pc = smccc_get_arg2(source_vcpu);
+	context_id = smccc_get_arg3(source_vcpu);
 
 	kvm_reset_vcpu(vcpu);
 
@@ -114,7 +146,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 	 * NOTE: We always update r0 (or x0) because for PSCI v0.1
 	 * the general puspose registers are undefined upon CPU_ON.
 	 */
-	vcpu_set_reg(vcpu, 0, context_id);
+	smccc_set_retval(vcpu, context_id, 0, 0, 0);
 	vcpu->arch.power_off = false;
 	smp_mb();		/* Make sure the above is visible */
 
@@ -134,8 +166,8 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
 	struct kvm *kvm = vcpu->kvm;
 	struct kvm_vcpu *tmp;
 
-	target_affinity = vcpu_get_reg(vcpu, 1);
-	lowest_affinity_level = vcpu_get_reg(vcpu, 2);
+	target_affinity = smccc_get_arg1(vcpu);
+	lowest_affinity_level = smccc_get_arg2(vcpu);
 
 	/* Determine target affinity mask */
 	target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
@@ -209,7 +241,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu)
 static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 {
 	struct kvm *kvm = vcpu->kvm;
-	unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
+	u32 psci_fn = smccc_get_function(vcpu);
 	unsigned long val;
 	int ret = 1;
 
@@ -276,14 +308,14 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 		break;
 	}
 
-	vcpu_set_reg(vcpu, 0, val);
+	smccc_set_retval(vcpu, val, 0, 0, 0);
 	return ret;
 }
 
 static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
 {
 	struct kvm *kvm = vcpu->kvm;
-	unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
+	u32 psci_fn = smccc_get_function(vcpu);
 	unsigned long val;
 
 	switch (psci_fn) {
@@ -301,7 +333,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
 		break;
 	}
 
-	vcpu_set_reg(vcpu, 0, val);
+	smccc_set_retval(vcpu, val, 0, 0, 0);
 	return 1;
 }
 
-- 
2.16.2.440.gc6284da