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, 12 insertions, 5 deletions

diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index 0ad683dab1e2..e6fa1e2982c8 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -58,11 +58,18 @@ extern void fpsimd_restore_current_state(void);
 extern void fpsimd_update_current_state(struct user_fpsimd_state const *state);
 extern void fpsimd_kvm_prepare(void);
 
-extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state,
-				     void *sve_state, unsigned int sve_vl,
-				     void *za_state, unsigned int sme_vl,
-				     u64 *svcr, enum fp_type *type,
-				     enum fp_type to_save);
+struct cpu_fp_state {
+	struct user_fpsimd_state *st;
+	void *sve_state;
+	void *za_state;
+	u64 *svcr;
+	unsigned int sve_vl;
+	unsigned int sme_vl;
+	enum fp_type *fp_type;
+	enum fp_type to_save;
+};
+
+extern void fpsimd_bind_state_to_cpu(struct cpu_fp_state *fp_state);
 
 extern void fpsimd_flush_task_state(struct task_struct *target);
 extern void fpsimd_save_and_flush_cpu_state(void);