[PATCH v2 1/3] cacheinfo: Check sib_leaf in cache_leaves_are_shared()

From: Pierre Gondois
Date: Wed Apr 12 2023 - 03:19:00 EST


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.

Check 'sib_leaf->level'. Also update the comment as the function is
called when populating 'shared_cpu_map'.

Fixes: f16d1becf96f ("cacheinfo: Use cache identifiers to check if the caches are shared if available")
Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx>
---
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 f3903d002819..e7ad6aba5f97 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