[PATCH 1/2] arm64/sve: Factor out FPSIMD to SVE state conversion

Currently we convert from FPSIMD to SVE register state in memory in
two places.

We are about to amend the way this works, so factor this operation
out so that subsequent changes only have to be made in one place.

Signed-off-by: Dave Martin <[email protected]>
---
 arch/arm64/kernel/fpsimd.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index a38bf74..61ceeb9 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -352,6 +352,16 @@ static int __init sve_sysctl_init(void) { return 0; }
 #define ZREG(sve_state, vq, n) ((char *)(sve_state) +		\
 	(SVE_SIG_ZREG_OFFSET(vq, n) - SVE_SIG_REGS_OFFSET))
 
+static void __fpsimd_to_sve(void *sst, struct user_fpsimd_state const *fst,
+			    unsigned int vq)
+{
+	unsigned int i;
+
+	for (i = 0; i < 32; ++i)
+		memcpy(ZREG(sst, vq, i), &fst->vregs[i],
+		       sizeof(fst->vregs[i]));
+}
+
 /*
  * Transfer the FPSIMD state in task->thread.uw.fpsimd_state to
  * task->thread.sve_state.
@@ -368,15 +378,12 @@ static void fpsimd_to_sve(struct task_struct *task)
 	unsigned int vq;
 	void *sst = task->thread.sve_state;
 	struct user_fpsimd_state const *fst = &task->thread.uw.fpsimd_state;
-	unsigned int i;
 
 	if (!system_supports_sve())
 		return;
 
 	vq = sve_vq_from_vl(task->thread.sve_vl);
-	for (i = 0; i < 32; ++i)
-		memcpy(ZREG(sst, vq, i), &fst->vregs[i],
-		       sizeof(fst->vregs[i]));
+	__fpsimd_to_sve(sst, fst, vq);
 }
 
 /*
@@ -490,7 +497,6 @@ void sve_sync_from_fpsimd_zeropad(struct task_struct *task)
 	unsigned int vq;
 	void *sst = task->thread.sve_state;
 	struct user_fpsimd_state const *fst = &task->thread.uw.fpsimd_state;
-	unsigned int i;
 
 	if (!test_tsk_thread_flag(task, TIF_SVE))
 		return;
@@ -498,10 +504,7 @@ void sve_sync_from_fpsimd_zeropad(struct task_struct *task)
 	vq = sve_vq_from_vl(task->thread.sve_vl);
 
 	memset(sst, 0, SVE_SIG_REGS_SIZE(vq));
-
-	for (i = 0; i < 32; ++i)
-		memcpy(ZREG(sst, vq, i), &fst->vregs[i],
-		       sizeof(fst->vregs[i]));
+	__fpsimd_to_sve(sst, fst, vq);
 }
 
 int sve_set_vector_length(struct task_struct *task,
-- 
2.1.4