[PATCH 1/3] cacheinfo: Check sib_leaf in cache_leaves_are_shared()

Pierre Gondois
2023-03-27T12:01:29Z

If 'this_leaf' is a L2 cache (or higher) and 'sib_leaf' is a L1 cache,
the caches are detected as shared.
Indeed, cache_leaves_are_shared() only checks the cache level of
'this_leaf' when 'sib_leaf''s cache level should also be checked.

Also update the comment: the function is called when populating
'shared_cpu_map'.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
drivers/base/cacheinfo.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index f6573c335f4c..4ca117574af1 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -38,11 +38,10 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
{
/*
* For non DT/ACPI systems, assume unique level 1 caches,
- * system-wide shared caches for all other levels. This will be used
- * only if arch specific code has not populated shared_cpu_map
+ * system-wide shared caches for all other levels.
*/
if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)))
- return !(this_leaf->level == 1);
+ return (this_leaf->level != 1) || (sib_leaf->level != 1);

if ((sib_leaf->attributes & CACHE_ID) &&
(this_leaf->attributes & CACHE_ID))
--
2.25.1