[PATCH v4 1/3] KVM: arm64: Avoid re-testing walk_continue

[Leonardo Bras]

__kvm_pgtable_visit() performs a bunch of calls to
kvm_pgtable_walk_continue() to find out whether the walk can continue
further, and if not, 'goto out', which retests the possibility of
continuing the walk before exiting.

Given that it's testing the same ret variable again, there is no reason
the result of kvm_pgtable_walk_continue() would have changed since the
previous check. So turn this goto into an early return, simplifying the
code and paving the way for further rework."

Signed-off-by: Leonardo Bras <leo.bras@xxxxxxx>
---
 arch/arm64/kvm/hyp/pgtable.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index b74dd5ce1efd..7a51f78b6446 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -183,32 +183,32 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data,
 	 * Reload the page table after invoking the walker callback for leaf
 	 * entries or after pre-order traversal, to allow the walker to descend
 	 * into a newly installed or replaced table.
 	 */
 	if (reload) {
 		ctx.old = READ_ONCE(*ptep);
 		table = kvm_pte_table(ctx.old, level);
 	}
 
 	if (!kvm_pgtable_walk_continue(data->walker, ret))
-		goto out;
+		return ret;
 
 	if (!table) {
 		data->addr = ALIGN_DOWN(data->addr, kvm_granule_size(level));
 		data->addr += kvm_granule_size(level);
 		goto out;
 	}
 
 	childp = (kvm_pteref_t)kvm_pte_follow(ctx.old, mm_ops);
 	ret = __kvm_pgtable_walk(data, mm_ops, childp, level + 1);
 	if (!kvm_pgtable_walk_continue(data->walker, ret))
-		goto out;
+		return ret;
 
 	if (ctx.flags & KVM_PGTABLE_WALK_TABLE_POST)
 		ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_TABLE_POST);
 
 out:
 	if (kvm_pgtable_walk_continue(data->walker, ret))
 		return 0;
 
 	return ret;
 }
-- 
2.55.0