Staging
v0.7.0
v0.7.0
https://github.com/torvalds/linux
Tip revision: 6d796c50f84ca79f1722bb131799e5a5710c4700 authored by Linus Torvalds on 29 January 2023, 21:59:43 UTC
Linux 6.2-rc6
Linux 6.2-rc6
Tip revision: 6d796c5
cache.c
// SPDX-License-Identifier: GPL-2.0
/*
* Extract CPU cache information and expose them via sysfs.
*
* Copyright IBM Corp. 2012
*/
#include <linux/seq_file.h>
#include <linux/cpu.h>
#include <linux/cacheinfo.h>
#include <asm/facility.h>
enum {
CACHE_SCOPE_NOTEXISTS,
CACHE_SCOPE_PRIVATE,
CACHE_SCOPE_SHARED,
CACHE_SCOPE_RESERVED,
};
enum {
CTYPE_SEPARATE,
CTYPE_DATA,
CTYPE_INSTRUCTION,
CTYPE_UNIFIED,
};
enum {
EXTRACT_TOPOLOGY,
EXTRACT_LINE_SIZE,
EXTRACT_SIZE,
EXTRACT_ASSOCIATIVITY,
};
enum {
CACHE_TI_UNIFIED = 0,
CACHE_TI_DATA = 0,
CACHE_TI_INSTRUCTION,
};
struct cache_info {
unsigned char : 4;
unsigned char scope : 2;
unsigned char type : 2;
};
#define CACHE_MAX_LEVEL 8
union cache_topology {
struct cache_info ci[CACHE_MAX_LEVEL];
unsigned long long raw;
};
static const char * const cache_type_string[] = {
"",
"Instruction",
"Data",
"",
"Unified",
};
static const enum cache_type cache_type_map[] = {
[CTYPE_SEPARATE] = CACHE_TYPE_SEPARATE,
[CTYPE_DATA] = CACHE_TYPE_DATA,
[CTYPE_INSTRUCTION] = CACHE_TYPE_INST,
[CTYPE_UNIFIED] = CACHE_TYPE_UNIFIED,
};
void show_cacheinfo(struct seq_file *m)
{
struct cpu_cacheinfo *this_cpu_ci;
struct cacheinfo *cache;
int idx;
this_cpu_ci = get_cpu_cacheinfo(cpumask_any(cpu_online_mask));
for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) {
cache = this_cpu_ci->info_list + idx;
seq_printf(m, "cache%-11d: ", idx);
seq_printf(m, "level=%d ", cache->level);
seq_printf(m, "type=%s ", cache_type_string[cache->type]);
seq_printf(m, "scope=%s ",
cache->disable_sysfs ? "Shared" : "Private");
seq_printf(m, "size=%dK ", cache->size >> 10);
seq_printf(m, "line_size=%u ", cache->coherency_line_size);
seq_printf(m, "associativity=%d", cache->ways_of_associativity);
seq_puts(m, "\n");
}
}
static inline enum cache_type get_cache_type(struct cache_info *ci, int level)
{
if (level >= CACHE_MAX_LEVEL)
return CACHE_TYPE_NOCACHE;
ci += level;
if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE)
return CACHE_TYPE_NOCACHE;
return cache_type_map[ci->type];
}
static inline unsigned long ecag(int ai, int li, int ti)
{
return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti);
}
static void ci_leaf_init(struct cacheinfo *this_leaf, int private,
enum cache_type type, unsigned int level, int cpu)
{
int ti, num_sets;
if (type == CACHE_TYPE_INST)
ti = CACHE_TI_INSTRUCTION;
else
ti = CACHE_TI_UNIFIED;
this_leaf->level = level + 1;
this_leaf->type = type;
this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti);
this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti);
this_leaf->size = ecag(EXTRACT_SIZE, level, ti);
num_sets = this_leaf->size / this_leaf->coherency_line_size;
num_sets /= this_leaf->ways_of_associativity;
this_leaf->number_of_sets = num_sets;
cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
if (!private)
this_leaf->disable_sysfs = true;
}
int init_cache_level(unsigned int cpu)
{
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
unsigned int level = 0, leaves = 0;
union cache_topology ct;
enum cache_type ctype;
if (!this_cpu_ci)
return -EINVAL;
ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
do {
ctype = get_cache_type(&ct.ci[0], level);
if (ctype == CACHE_TYPE_NOCACHE)
break;
/* Separate instruction and data caches */
leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
} while (++level < CACHE_MAX_LEVEL);
this_cpu_ci->num_levels = level;
this_cpu_ci->num_leaves = leaves;
return 0;
}
int populate_cache_leaves(unsigned int cpu)
{
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
struct cacheinfo *this_leaf = this_cpu_ci->info_list;
unsigned int level, idx, pvt;
union cache_topology ct;
enum cache_type ctype;
ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
for (idx = 0, level = 0; level < this_cpu_ci->num_levels &&
idx < this_cpu_ci->num_leaves; idx++, level++) {
if (!this_leaf)
return -EINVAL;
pvt = (ct.ci[level].scope == CACHE_SCOPE_PRIVATE) ? 1 : 0;
ctype = get_cache_type(&ct.ci[0], level);
if (ctype == CACHE_TYPE_SEPARATE) {
ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_DATA, level, cpu);
ci_leaf_init(this_leaf++, pvt, CACHE_TYPE_INST, level, cpu);
} else {
ci_leaf_init(this_leaf++, pvt, ctype, level, cpu);
}
}
return 0;
}