On 14/09/18 17:28, Jeffrey Hugo wrote: > The type of a cache might not be specified by architectural mechanisms (ie > system registers), but its type might be specified in the PPTT. In this > case, we should populate the type of the cache, rather than leave it > undefined. > > This fixes the issue where the cacheinfo driver will not populate sysfs > for such caches, resulting in the information missing from utilities like > lstopo and lscpu, thus degrading the user experience. > > Fixes: 2bd00bcd73e5 (ACPI/PPTT: Add Processor Properties Topology Table parsing) > Reported-by: Vijaya Kumar K <vkilari@xxxxxxxxxxxxxx> > Signed-off-by: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx> > --- > drivers/acpi/pptt.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c > index d1e26cb..bb00ed9 100644 > --- a/drivers/acpi/pptt.c > +++ b/drivers/acpi/pptt.c > @@ -402,11 +402,18 @@ static void update_cache_properties(struct cacheinfo *this_leaf, > } > } > /* > - * If the above flags are valid, and the cache type is NOCACHE > - * update the cache type as well. > + * If cache type is NOCACHE, then the cache hasn't been specified > + * via other mechanisms. Update the type if either the cache has > + * been fully specified in PPTT, or a cache type has been provided. > + * > + * Note, we assume such caches are unified based on conventional system > + * design and known examples. Significant work is required elsewhere to > + * fully support data/instruction only type caches which are only > + * specified in PPTT. > */ > - if (this_leaf->type == CACHE_TYPE_NOCACHE && > - valid_flags == PPTT_CHECKED_ATTRIBUTES) > + if ((this_leaf->type == CACHE_TYPE_NOCACHE) && > + (valid_flags == PPTT_CHECKED_ATTRIBUTES || > + found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)) > this_leaf->type = CACHE_TYPE_UNIFIED; I thought I did mention that we can drop the valid_flags altogether unless Jeremy has reasons not to. -- Regards, Sudeep
