Files
linux-stable-mirror/include/linux/cacheinfo.h
T
Chen Yu 7030513a08 sched/cache: Calculate the LLC size and store it in sched_domain
Cache aware scheduling needs to know the LLC size that a process
can use, so as to avoid memory-intensive tasks from being
over-aggregated on a single LLC.

Introduce a preparation patch to add get_effective_llc_bytes() to
get the LLC size that a CPU can use. The function can be further
enhanced by subtracting the LLC cache ways reserved by resctrl
(CAT in Intel RDT, etc).

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Tingyin Duan <tingyin.duan@gmail.com>
Link: https://patch.msgid.link/37afee09ff608034da0ce149e72d33b6f4698edf.1778703694.git.tim.c.chen@linux.intel.com
2026-05-18 21:33:15 +02:00

170 lines
5.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_CACHEINFO_H
#define _LINUX_CACHEINFO_H
#include <linux/bitops.h>
#include <linux/cpuhplock.h>
#include <linux/cpumask_types.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);
struct cacheinfo *get_cpu_cacheinfo_llc(unsigned int cpu);
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 cacheinfo structure for the cache associated with @cpu at
* level @level.
* cpuhp lock must be held.
*/
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];
return NULL;
}
}
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;
}
#if defined(CONFIG_ARM64) || defined(CONFIG_ARM)
#define use_arch_cache_info() (true)
#else
#define use_arch_cache_info() (false)
#endif
#ifndef CONFIG_ARCH_HAS_CPU_CACHE_ALIASING
#define cpu_dcache_is_aliasing() false
#define cpu_icache_is_aliasing() cpu_dcache_is_aliasing()
#else
#include <asm/cachetype.h>
#ifndef cpu_icache_is_aliasing
#define cpu_icache_is_aliasing() cpu_dcache_is_aliasing()
#endif
#endif
#endif /* _LINUX_CACHEINFO_H */