arm64/fp: Use a struct to pass data to fpsimd_bind_state_to_cpu()

For reasons that are unclear to this reader fpsimd_bind_state_to_cpu()
populates the struct fpsimd_last_state_struct that it uses to store the
active floating point state for KVM guests by passing an argument for
each member of the structure. As the richness of the architecture increases
this is resulting in a function with a rather large number of arguments
which isn't ideal.

Simplify the interface by using the struct directly as the single argument
for the function, renaming it as we lift the definition into the header.
This could be built on further to reduce the work we do adding storage for
new FP state in various places but for now it just simplifies this one
interface.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221115094640.112848-9-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 14 insertions, 10 deletions

diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index ec82d0191f76..02dd7e9ebd39 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -130,25 +130,29 @@ void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu)
  */
 void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
 {
-	enum fp_type fp_type;
+	struct cpu_fp_state fp_state;
 
 	WARN_ON_ONCE(!irqs_disabled());
 
 	if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) {
-		if (vcpu_has_sve(vcpu))
-			fp_type = FP_STATE_SVE;
-		else
-			fp_type = FP_STATE_FPSIMD;
 
 		/*
 		 * Currently we do not support SME guests so SVCR is
 		 * always 0 and we just need a variable to point to.
 		 */
-		fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.fp_regs,
-					 vcpu->arch.sve_state,
-					 vcpu->arch.sve_max_vl,
-					 NULL, 0, &vcpu->arch.svcr,
-					 &vcpu->arch.fp_type, fp_type);
+		fp_state.st = &vcpu->arch.ctxt.fp_regs;
+		fp_state.sve_state = vcpu->arch.sve_state;
+		fp_state.sve_vl = vcpu->arch.sve_max_vl;
+		fp_state.za_state = NULL;
+		fp_state.svcr = &vcpu->arch.svcr;
+		fp_state.fp_type = &vcpu->arch.fp_type;
+
+		if (vcpu_has_sve(vcpu))
+			fp_state.to_save = FP_STATE_SVE;
+		else
+			fp_state.to_save = FP_STATE_FPSIMD;
+
+		fpsimd_bind_state_to_cpu(&fp_state);
 
 		clear_thread_flag(TIF_FOREIGN_FPSTATE);
 	}