arm/arm64: KVM: Add smccc accessors to PSCI code

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

commit 84684fecd7ea381824a96634a027b7719587fb77 upstream.

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

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[v4.9: account for files moved to virt/ upstream]
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
Tested-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 5d8ad0e..f579ed9 100644 (file)
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -32,6 +32,38 @@
 
 #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)
@@ -74,7 +106,7 @@ 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);
 
@@ -93,8 +125,8 @@ 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);
 
@@ -113,7 +145,7 @@ 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 */
 
@@ -133,8 +165,8 @@ 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);
@@ -208,7 +240,7 @@ 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);
+       unsigned long psci_fn = smccc_get_function(vcpu);
        unsigned long val;
        int ret = 1;
 
@@ -275,14 +307,14 @@ 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);
+       unsigned long psci_fn = smccc_get_function(vcpu);
        unsigned long val;
 
        switch (psci_fn) {
@@ -300,7 +332,7 @@ 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;
 }