Commit 685cb167 authored by Tony Luck's avatar Tony Luck Committed by Borislav Petkov (AMD)
Browse files

cacheinfo: Add function to get cacheinfo for a given CPU and cache level 



Resctrl open codes a search for information about a given cache level in
a couple of places (and more are on the way).

Provide a new inline function get_cpu_cacheinfo_level() in
<linux/cacheinfo.h> to do the search and return a pointer to the
cacheinfo structure.

Add lockdep_assert_cpus_held() to enforce the comment that cpuhp lock
must be held.

Simplify the existing get_cpu_cacheinfo_id() by using this new function
to do the search.

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240610003927.341707-4-tony.luck@intel.com
parent ddefcfde

include/linux/cacheinfo.h

+20 −5
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#define _LINUX_CACHEINFO_H



#include <linux/bitops.h>

#include <linux/cpuhplock.h>

#include <linux/cpumask.h>

#include <linux/smp.h>
@@ -113,23 +114,37 @@ int acpi_get_cache_info(unsigned int cpu, 
const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);



/*

 * Get the id of the cache associated with @cpu at level @level.

 * Get the cacheinfo structure for the cache associated with @cpu at

 * level @level.

 * cpuhp lock must be held.

 */

static inline int get_cpu_cacheinfo_id(int cpu, int level)

static inline struct cacheinfo *get_cpu_cacheinfo_level(int cpu, int level)

{

	struct cpu_cacheinfo *ci = get_cpu_cacheinfo(cpu);

	int i;



	lockdep_assert_cpus_held();



	for (i = 0; i < ci->num_leaves; i++) {

		if (ci->info_list[i].level == level) {

			if (ci->info_list[i].attributes & CACHE_ID)

				return ci->info_list[i].id;

			return -1;

				return &ci->info_list[i];

			return NULL;

		}

	}



	return -1;

	return NULL;

}



/*

 * Get the id of the cache associated with @cpu at level @level.

 * cpuhp lock must be held.

 */

static inline int get_cpu_cacheinfo_id(int cpu, int level)

{

	struct cacheinfo *ci = get_cpu_cacheinfo_level(cpu, level);



	return ci ? ci->id : -1;

}



#ifdef CONFIG_ARM64