linux-stable/include/linux/cacheinfo.h
Huang Ying 94a3bfe407 cacheinfo: calculate size of per-CPU data cache slice
This can be used to estimate the size of the data cache slice that can be
used by one CPU under ideal circumstances.  Both DATA caches and UNIFIED
caches are used in calculation.  So, the users need to consider the impact
of the code cache usage.

Because the cache inclusive/non-inclusive information isn't available now,
we just use the size of the per-CPU slice of LLC to make the result more
predictable across architectures.  This may be improved when more cache
information is available in the future.

A brute-force algorithm to iterate all online CPUs is used to avoid to
allocate an extra cpumask, especially in offline callback.

Link: https://lkml.kernel.org/r/20231016053002.756205-3-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-25 16:47:10 -07:00

141 lines
4.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_CACHEINFO_H
#define _LINUX_CACHEINFO_H
#include <linux/bitops.h>
#include <linux/cpumask.h>
#include <linux/smp.h>
struct device_node;
struct attribute;
enum cache_type {
CACHE_TYPE_NOCACHE = 0,
CACHE_TYPE_INST = BIT(0),
CACHE_TYPE_DATA = BIT(1),
CACHE_TYPE_SEPARATE = CACHE_TYPE_INST | CACHE_TYPE_DATA,
CACHE_TYPE_UNIFIED = BIT(2),
};
extern unsigned int coherency_max_size;
/**
* struct cacheinfo - represent a cache leaf node
* @id: This cache's id. It is unique among caches with the same (type, level).
* @type: type of the cache - data, inst or unified
* @level: represents the hierarchy in the multi-level cache
* @coherency_line_size: size of each cache line usually representing
* the minimum amount of data that gets transferred from memory
* @number_of_sets: total number of sets, a set is a collection of cache
* lines sharing the same index
* @ways_of_associativity: number of ways in which a particular memory
* block can be placed in the cache
* @physical_line_partition: number of physical cache lines sharing the
* same cachetag
* @size: Total size of the cache
* @shared_cpu_map: logical cpumask representing all the cpus sharing
* this cache node
* @attributes: bitfield representing various cache attributes
* @fw_token: Unique value used to determine if different cacheinfo
* structures represent a single hardware cache instance.
* @disable_sysfs: indicates whether this node is visible to the user via
* sysfs or not
* @priv: pointer to any private data structure specific to particular
* cache design
*
* While @of_node, @disable_sysfs and @priv are used for internal book
* keeping, the remaining members form the core properties of the cache
*/
struct cacheinfo {
unsigned int id;
enum cache_type type;
unsigned int level;
unsigned int coherency_line_size;
unsigned int number_of_sets;
unsigned int ways_of_associativity;
unsigned int physical_line_partition;
unsigned int size;
cpumask_t shared_cpu_map;
unsigned int attributes;
#define CACHE_WRITE_THROUGH BIT(0)
#define CACHE_WRITE_BACK BIT(1)
#define CACHE_WRITE_POLICY_MASK \
(CACHE_WRITE_THROUGH | CACHE_WRITE_BACK)
#define CACHE_READ_ALLOCATE BIT(2)
#define CACHE_WRITE_ALLOCATE BIT(3)
#define CACHE_ALLOCATE_POLICY_MASK \
(CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE)
#define CACHE_ID BIT(4)
void *fw_token;
bool disable_sysfs;
void *priv;
};
struct cpu_cacheinfo {
struct cacheinfo *info_list;
unsigned int per_cpu_data_slice_size;
unsigned int num_levels;
unsigned int num_leaves;
bool cpu_map_populated;
bool early_ci_levels;
};
struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
int early_cache_level(unsigned int cpu);
int init_cache_level(unsigned int cpu);
int init_of_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);
int fetch_cache_info(unsigned int cpu);
int detect_cache_attributes(unsigned int cpu);
#ifndef CONFIG_ACPI_PPTT
/*
* acpi_get_cache_info() is only called on ACPI enabled
* platforms using the PPTT for topology. This means that if
* the platform supports other firmware configuration methods
* we need to stub out the call when ACPI is disabled.
* ACPI enabled platforms not using PPTT won't be making calls
* to this function so we need not worry about them.
*/
static inline
int acpi_get_cache_info(unsigned int cpu,
unsigned int *levels, unsigned int *split_levels)
{
return -ENOENT;
}
#else
int acpi_get_cache_info(unsigned int cpu,
unsigned int *levels, unsigned int *split_levels);
#endif
const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);
/*
* 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 cpu_cacheinfo *ci = get_cpu_cacheinfo(cpu);
int i;
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 -1;
}
#ifdef CONFIG_ARM64
#define use_arch_cache_info() (true)
#else
#define use_arch_cache_info() (false)
#endif
#endif /* _LINUX_CACHEINFO_H */