qiurui
/
Centos-kernel-stream-9
mirror of https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

cacheinfo: Add support to check if last level cache(LLC) is valid or shared 

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2122318

commit cc1cfc47ea47187a21ec1f079b3c53264157fe15
Author: Sudeep Holla <sudeep.holla@arm.com>
Date: Mon, 4 Jul 2022 11:15:49 +0100

It is useful to have helper to check if the given two CPUs share last
level cache. We can do that check by comparing fw_token or by comparing
the cache ID. Currently we check just for fw_token as the cache ID is
optional.

This helper can be used to build the llc_sibling during arch specific
topology parsing and feeding information to the sched_domains. This also
helps to get rid of llc_id in the CPU topology as it is sort of duplicate
information.

Also add helper to check if the llc information in cacheinfo is valid
or not.

Link: https://lore.kernel.org/r/20220704101605.1318280-6-sudeep.holla@arm.com
Tested-by: Ionela Voinescu <ionela.voinescu@arm.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mark Langsdorf <mlangsdo@redhat.com>
This commit is contained in:
Mark Langsdorf 2022-08-22 16:27:56 -04:00
parent 6258474f9f
commit ab49e7ba77
2 changed files with 28 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/base/cacheinfo.c
View File

@ -47,6 +47,32 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
return sib_leaf->fw_token == this_leaf->fw_token;
}
bool last_level_cache_is_valid(unsigned int cpu)
{
struct cacheinfo *llc;
if (!cache_leaves(cpu))
return false;
llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
return !!llc->fw_token;
}
bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
{
struct cacheinfo *llc_x, *llc_y;
if (!last_level_cache_is_valid(cpu_x) ||
!last_level_cache_is_valid(cpu_y))
return false;
llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1);
llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1);
return cache_leaves_are_shared(llc_x, llc_y);
}
#ifdef CONFIG_OF
/* OF properties to query for a given cache type */
struct cache_type_info {

2
include/linux/cacheinfo.h
View File

@ -82,6 +82,8 @@ struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
int init_cache_level(unsigned int cpu);
int populate_cache_leaves(unsigned int cpu);
int cache_setup_acpi(unsigned int cpu);
bool last_level_cache_is_valid(unsigned int cpu);
bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y);
#ifndef CONFIG_ACPI_PPTT
/*
* acpi_find_last_cache_level is only called on ACPI enabled