[PATCH RFC] cache: Make cpu_cache_invalidate_memregion() error out if there are no handlers

[Bence Csokas <bence.csokas@arm.com>]

Currently, if there are no registered handlers,
cpu_cache_invalidate_memregion() returns 0. Callers are expected to check
cpu_cache_has_invalidate_memregion() and return -ENXIO themselves, instead
of calling this function. If a caller forgets to do this, they may
erroneously think the operation succeeded. This is in contrast to x86,
where cpu_cache_invalidate_memregion() itself checks if the operation is
supported, and returns -ENXIO if it is not.

Signed-off-by: Bence Csokas <bence.csokas@arm.com>
---
 lib/cache_maint.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/cache_maint.c b/lib/cache_maint.c
index 9256a9ffc34c..132d2816d6b1 100644
--- a/lib/cache_maint.c
+++ b/lib/cache_maint.c
@@ -59,12 +59,12 @@ static int cache_inval_done_one(struct cache_coherency_ops_inst *cci)
 
 static int cache_invalidate_memregion(phys_addr_t addr, size_t size)
 {
-	int ret;
 	struct cache_coherency_ops_inst *cci;
 	struct cc_inval_params params = {
 		.addr = addr,
 		.size = size,
 	};
+	int ret = -ENXIO;
 
 	guard(rwsem_read)(&cache_ops_instance_list_lock);
 	list_for_each_entry(cci, &cache_ops_instance_list, node) {
@@ -78,7 +78,7 @@ static int cache_invalidate_memregion(phys_addr_t addr, size_t size)
 			return ret;
 	}
 
-	return 0;
+	return ret;
 }
 
 struct cache_coherency_ops_inst *

-- 
2.55.0