Quelle  cacheinfo.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * LoongArch cacheinfo support
 *
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */
#include <linux/cacheinfo.h>
#include <linux/topology.h>
#include <asm/bootinfo.h>
#include <asm/cpu-info.h>

int init_cache_level(unsigned int cpu)
{
 int cache_present = current_cpu_data.cache_leaves_present;
 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);

 this_cpu_ci->num_levels =
  current_cpu_data.cache_leaves[cache_present - 1].level;
 this_cpu_ci->num_leaves = cache_present;

 return 0;
}

static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
        struct cacheinfo *sib_leaf)
{
 return (!(*(unsigned char *)(this_leaf->priv) & CACHE_PRIVATE)
  && !(*(unsigned char *)(sib_leaf->priv) & CACHE_PRIVATE));
}

static void cache_cpumap_setup(unsigned int cpu)
{
 unsigned int index;
 struct cacheinfo *this_leaf, *sib_leaf;
 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);

 for (index = 0; index < this_cpu_ci->num_leaves; index++) {
  unsigned int i;

  this_leaf = this_cpu_ci->info_list + index;
  /* skip if shared_cpu_map is already populated */
  if (!cpumask_empty(&this_leaf->shared_cpu_map))
   continue;

  cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
  for_each_online_cpu(i) {
   struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);

   if (i == cpu || !sib_cpu_ci->info_list ||
    (cpu_to_node(i) != cpu_to_node(cpu)))
    continue;

   sib_leaf = sib_cpu_ci->info_list + index;
   /* SMT cores share all caches */
   if (cpus_are_siblings(i, cpu)) {
    cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
    cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
   }
   /* Node's cores share shared caches */
   if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
    cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
    cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
   }
  }
 }
}

int populate_cache_leaves(unsigned int cpu)
{
 int i, cache_present = current_cpu_data.cache_leaves_present;
 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 struct cacheinfo *this_leaf = this_cpu_ci->info_list;
 struct cache_desc *cd, *cdesc = current_cpu_data.cache_leaves;

 for (i = 0; i < cache_present; i++) {
  cd = cdesc + i;

  this_leaf->type = cd->type;
  this_leaf->level = cd->level;
  this_leaf->coherency_line_size = cd->linesz;
  this_leaf->number_of_sets = cd->sets;
  this_leaf->ways_of_associativity = cd->ways;
  this_leaf->size = cd->linesz * cd->sets * cd->ways;
  this_leaf->priv = &cd->flags;
  this_leaf++;
 }

 cache_cpumap_setup(cpu);
 this_cpu_ci->cpu_map_populated = true;

 return 0;
}