From: Sudeep Holla Date: Mon, 4 Jul 2022 10:15:51 +0000 (+0100) Subject: cacheinfo: Use cache identifiers to check if the caches are shared if available X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f16d1becf96f0a95dc9e1a5a7f97feeec2b149d5;p=linux.git cacheinfo: Use cache identifiers to check if the caches are shared if available The cache identifiers is an optional property on most of the platforms. The presence of one must be indicated by the CACHE_ID valid bit in the attributes. We can use the cache identifiers provided by the firmware to check if any two cpus share the same cache instead of relying on the fw_token generated and set in the OS. Link: https://lore.kernel.org/r/20220704101605.1318280-8-sudeep.holla@arm.com Tested-by: Ionela Voinescu Tested-by: Conor Dooley Signed-off-by: Sudeep Holla --- diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 4d21a1022fa92..e331b399adeb7 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -44,6 +44,10 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI))) return !(this_leaf->level == 1); + if ((sib_leaf->attributes & CACHE_ID) && + (this_leaf->attributes & CACHE_ID)) + return sib_leaf->id == this_leaf->id; + return sib_leaf->fw_token == this_leaf->fw_token; } @@ -56,7 +60,8 @@ bool last_level_cache_is_valid(unsigned int cpu) llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1); - return !!llc->fw_token; + return (llc->attributes & CACHE_ID) || !!llc->fw_token; + } bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)