// SPDX-License-Identifier: GPL-2.0-only/* * Processor cache information made available to userspace via sysfs; * intended to be compatible with x86 intel_cacheinfo implementation. * * Copyright 2008 IBM Corporation * Author: Nathan Lynch */ #define pr_fmt(fmt) "cacheinfo: " fmt #include <linux/cpu.h>#include <linux/cpumask.h>#include <linux/kernel.h>#include <linux/kobject.h>#include <linux/list.h>#include <linux/notifier.h>#include <linux/of.h>#include <linux/percpu.h>#include <linux/slab.h>#include <linux/sysfs.h>#include <asm/cputhreads.h>#include <asm/smp.h> #include "cacheinfo.h" /* per-cpu object for tracking: * - a "cache" kobject for the top-level directory * - a list of "index" objects representing the cpu's local cache hierarchy */struct cache_dir { struct kobject *kobj; /* bare (not embedded) kobject for cache * directory */ struct cache_index_dir *index; /* list of index objects */}; /* "index" object: each cpu's cache directory has an index * subdirectory corresponding to a cache object associated with the * cpu. This object's lifetime is managed via the embedded kobject. */struct cache_index_dir { struct kobject kobj; struct cache_index_dir *next; /* next index in parent directory */ struct cache *cache;}; /* Template for determining which OF properties to query for a given * cache type */struct cache_type_info { const char *name; const char *size_prop; /* Allow for both [di]-cache-line-size and * [di]-cache-block-size properties. According to the PowerPC * Processor binding, -line-size should be provided if it * differs from the cache block size (that which is operated * on by cache instructions), so we look for -line-size first. * See cache_get_line_size(). */ const char *line_size_props[2]; const char *nr_sets_prop;}; /* These are used to index the cache_type_info array. */#define CACHE_TYPE_UNIFIED 0 /* cache-size, cache-block-size, etc. */#define CACHE_TYPE_UNIFIED_D 1 /* d-cache-size, d-cache-block-size, etc */#define CACHE_TYPE_INSTRUCTION 2#define CACHE_TYPE_DATA 3 static const struct cache_type_info cache_type_info[] = { { /* Embedded systems that use cache-size, cache-block-size, * etc. for the Unified (typically L2) cache. */ .name = "Unified", .size_prop = "cache-size", .line_size_props = { "cache-line-size", "cache-block-size", }, .nr_sets_prop = "cache-sets", }, { /* PowerPC Processor binding says the [di]-cache-* * must be equal on unified caches, so just use * d-cache properties. */ .name = "Unified", .size_prop = "d-cache-size", .line_size_props = { "d-cache-line-size", "d-cache-block-size", }, .nr_sets_prop = "d-cache-sets", }, { .name = "Instruction", .size_prop = "i-cache-size", .line_size_props = { "i-cache-line-size", "i-cache-block-size", }, .nr_sets_prop = "i-cache-sets", }, { .name = "Data", .size_prop = "d-cache-size", .line_size_props = { "d-cache-line-size", "d-cache-block-size", }, .nr_sets_prop = "d-cache-sets", },}; /* Cache object: each instance of this corresponds to a distinct cache * in the system. There are separate objects for Harvard caches: one * each for instruction and data, and each refers to the same OF node. * The refcount of the OF node is elevated for the lifetime of the * cache object. A cache object is released when its shared_cpu_map * is cleared (see cache_cpu_clear). * * A cache object is on two lists: an unsorted global list * (cache_list) of cache objects; and a singly-linked list * representing the local cache hierarchy, which is ordered by level * (e.g. L1d -> L1i -> L2 -> L3). */struct cache { struct device_node *ofnode; /* OF node for this cache, may be cpu */ struct cpumask shared_cpu_map; /* online CPUs using this cache */ int type; /* split cache disambiguation */ int level; /* level not explicit in device tree */ int group_id; /* id of the group of threads that share this cache */ struct list_head list; /* global list of cache objects */ struct cache *next_local; /* next cache of >= level */}; static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu); /* traversal/modification of this list occurs only at cpu hotplug time; * access is serialized by cpu hotplug locking */static LIST_HEAD(cache_list); static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k){ return container_of(k, struct cache_index_dir, kobj);} static const char *cache_type_string(const struct cache *cache){ return cache_type_info[cache->type].name;} static void cache_init(struct cache *cache, int type, int level, struct device_node *ofnode, int group_id){ cache->type = type; cache->level = level; cache->ofnode = of_node_get(ofnode); cache->group_id = group_id; INIT_LIST_HEAD(&cache->list); list_add(&cache->list, &cache_list);} static struct cache *new_cache(int type, int level, struct device_node *ofnode, int group_id){ struct cache *cache; cache = kzalloc_obj(*cache); if (cache) cache_init(cache, type, level, ofnode, group_id); return cache;} static void release_cache_debugcheck(struct cache *cache){ struct cache *iter; list_for_each_entry(iter, &cache_list, list) WARN_ONCE(iter->next_local == cache, "cache for %pOFP(%s) refers to cache for %pOFP(%s)\n", iter->ofnode, cache_type_string(iter), cache->ofnode, cache_type_string(cache));} static void release_cache(struct cache *cache){ if (!cache) return; pr_debug("freeing L%d %s cache for %pOFP\n", cache->level, cache_type_string(cache), cache->ofnode); release_cache_debugcheck(cache); list_del(&cache->list); of_node_put(cache->ofnode); kfree(cache);} static void cache_cpu_set(struct cache *cache, int cpu){ struct cache *next = cache; while (next) { WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map), "CPU %i already accounted in %pOFP(%s)\n", cpu, next->ofnode, cache_type_string(next)); cpumask_set_cpu(cpu, &next->shared_cpu_map); next = next->next_local; }} static int cache_size(const struct cache *cache, unsigned int *ret){ const char *propname; const __be32 *cache_size; propname = cache_type_info[cache->type].size_prop; cache_size = of_get_property(cache->ofnode, propname, NULL); if (!cache_size) return -ENODEV; *ret = of_read_number(cache_size, 1); return 0;} static int cache_size_kb(const struct cache *cache, unsigned int *ret){ unsigned int size; if (cache_size(cache, &size)) return -ENODEV; *ret = size / 1024; return 0;} /* not cache_line_size() because that's a macro in include/linux/cache.h */static int cache_get_line_size(const struct cache *cache, unsigned int *ret){ const __be32 *line_size; int i, lim; lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props); for (i = 0; i < lim; i++) { const char *propname; propname = cache_type_info[cache->type].line_size_props[i]; line_size = of_get_property(cache->ofnode, propname, NULL); if (line_size) break; } if (!line_size) return -ENODEV; *ret = of_read_number(line_size, 1); return 0;} static int cache_nr_sets(const struct cache *cache, unsigned int *ret){ const char *propname; const __be32 *nr_sets; propname = cache_type_info[cache->type].nr_sets_prop; nr_sets = of_get_property(cache->ofnode, propname, NULL); if (!nr_sets) return -ENODEV; *ret = of_read_number(nr_sets, 1); return 0;} static int cache_associativity(const struct cache *cache, unsigned int *ret){ unsigned int line_size; unsigned int nr_sets; unsigned int size; if (cache_nr_sets(cache, &nr_sets)) goto err; /* If the cache is fully associative, there is no need to * check the other properties. */ if (nr_sets == 1) { *ret = 0; return 0; } if (cache_get_line_size(cache, &line_size)) goto err; if (cache_size(cache, &size)) goto err; if (!(nr_sets > 0 && size > 0 && line_size > 0)) goto err; *ret = (size / nr_sets) / line_size; return 0;err: return -ENODEV;} /* helper for dealing with split caches */static struct cache *cache_find_first_sibling(struct cache *cache){ struct cache *iter; if (cache->type == CACHE_TYPE_UNIFIED || cache->type == CACHE_TYPE_UNIFIED_D) return cache; list_for_each_entry(iter, &cache_list, list) if (iter->ofnode == cache->ofnode && iter->group_id == cache->group_id && iter->next_local == cache) return iter; return cache;} /* return the first cache on a local list matching node and thread-group id */static struct cache *cache_lookup_by_node_group(const struct device_node *node, int group_id){ struct cache *cache = NULL; struct cache *iter; list_for_each_entry(iter, &cache_list, list) { if (iter->ofnode != node || iter->group_id != group_id) continue; cache = cache_find_first_sibling(iter); break; } return cache;} static bool cache_node_is_unified(const struct device_node *np){ return of_get_property(np, "cache-unified", NULL);} /* * Unified caches can have two different sets of tags. Most embedded * use cache-size, etc. for the unified cache size, but open firmware systems * use d-cache-size, etc. Check on initialization for which type we have, and * return the appropriate structure type. Assume it's embedded if it isn't * open firmware. If it's yet a 3rd type, then there will be missing entries * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need * to be extended further. */static int cache_is_unified_d(const struct device_node *np){ return of_get_property(np, cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ? CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED;} static struct cache *cache_do_one_devnode_unified(struct device_node *node, int group_id, int level){ pr_debug("creating L%d ucache for %pOFP\n", level, node); return new_cache(cache_is_unified_d(node), level, node, group_id);} static struct cache *cache_do_one_devnode_split(struct device_node *node, int group_id, int level){ struct cache *dcache, *icache; pr_debug("creating L%d dcache and icache for %pOFP\n", level, node); dcache = new_cache(CACHE_TYPE_DATA, level, node, group_id); icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node, group_id); if (!dcache || !icache) goto err; dcache->next_local = icache; return dcache;err: release_cache(dcache); release_cache(icache); return NULL;} static struct cache *cache_do_one_devnode(struct device_node *node, int group_id, int level){ struct cache *cache; if (cache_node_is_unified(node)) cache = cache_do_one_devnode_unified(node, group_id, level); else cache = cache_do_one_devnode_split(node, group_id, level); return cache;} static struct cache *cache_lookup_or_instantiate(struct device_node *node, int group_id, int level){ struct cache *cache; cache = cache_lookup_by_node_group(node, group_id); WARN_ONCE(cache && cache->level != level, "cache level mismatch on lookup (got %d, expected %d)\n", cache->level, level); if (!cache) cache = cache_do_one_devnode(node, group_id, level); return cache;} static void link_cache_lists(struct cache *smaller, struct cache *bigger){ while (smaller->next_local) { if (smaller->next_local == bigger) return; /* already linked */ smaller = smaller->next_local; } smaller->next_local = bigger; /* * The cache->next_local list sorts by level ascending: * L1d -> L1i -> L2 -> L3 ... */ WARN_ONCE((smaller->level == 1 && bigger->level > 2) || (smaller->level > 1 && bigger->level != smaller->level + 1), "linking L%i cache %pOFP to L%i cache %pOFP; skipped a level?\n", smaller->level, smaller->ofnode, bigger->level, bigger->ofnode);} static void do_subsidiary_caches_debugcheck(struct cache *cache){ WARN_ONCE(cache->level != 1, "instantiating cache chain from L%d %s cache for " "%pOFP instead of an L1\n", cache->level, cache_type_string(cache), cache->ofnode); WARN_ONCE(!of_node_is_type(cache->ofnode, "cpu"), "instantiating cache chain from node %pOFP of type '%s' " "instead of a cpu node\n", cache->ofnode, of_node_get_device_type(cache->ofnode));} /* * If sub-groups of threads in a core containing @cpu_id share the * L@level-cache (information obtained via "ibm,thread-groups" * device-tree property), then we identify the group by the first * thread-sibling in the group. We define this to be the group-id. * * In the absence of any thread-group information for L@level-cache, * this function returns -1. */static int get_group_id(unsigned int cpu_id, int level){ if (has_big_cores && level == 1) return cpumask_first(per_cpu(thread_group_l1_cache_map, cpu_id)); else if (thread_group_shares_l2 && level == 2) return cpumask_first(per_cpu(thread_group_l2_cache_map, cpu_id)); else if (thread_group_shares_l3 && level == 3) return cpumask_first(per_cpu(thread_group_l3_cache_map, cpu_id)); return -1;} static void do_subsidiary_caches(struct cache *cache, unsigned int cpu_id){ struct device_node *subcache_node; int level = cache->level; do_subsidiary_caches_debugcheck(cache); while ((subcache_node = of_find_next_cache_node(cache->ofnode))) { struct cache *subcache; int group_id; level++; group_id = get_group_id(cpu_id, level); subcache = cache_lookup_or_instantiate(subcache_node, group_id, level); of_node_put(subcache_node); if (!subcache) break; link_cache_lists(cache, subcache); cache = subcache; }} Lines 1–500 of 955. 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// SPDX-License-Identifier: GPL-2.0-only /* * Processor cache information made available to userspace via sysfs; * intended to be compatible with x86 intel_cacheinfo implementation. * * Copyright 2008 IBM Corporation * Author: Nathan Lynch */ #define pr_fmt(fmt) "cacheinfo: " fmt #include <linux/cpu.h> #include <linux/cpumask.h> #include <linux/kernel.h> #include <linux/kobject.h> #include <linux/list.h> #include <linux/notifier.h> #include <linux/of.h> #include <linux/percpu.h> #include <linux/slab.h> #include <linux/sysfs.h> #include <asm/cputhreads.h> #include <asm/smp.h> #include "cacheinfo.h" /* per-cpu object for tracking: * - a "cache" kobject for the top-level directory * - a list of "index" objects representing the cpu's local cache hierarchy */ struct cache_dir { struct kobject *kobj; /* bare (not embedded) kobject for cache * directory */ struct cache_index_dir *index; /* list of index objects */ }; /* "index" object: each cpu's cache directory has an index * subdirectory corresponding to a cache object associated with the * cpu. This object's lifetime is managed via the embedded kobject. */ struct cache_index_dir { struct kobject kobj; struct cache_index_dir *next; /* next index in parent directory */ struct cache *cache; }; /* Template for determining which OF properties to query for a given * cache type */ struct cache_type_info { const char *name; const char *size_prop; /* Allow for both [di]-cache-line-size and * [di]-cache-block-size properties. According to the PowerPC * Processor binding, -line-size should be provided if it * differs from the cache block size (that which is operated * on by cache instructions), so we look for -line-size first. * See cache_get_line_size(). */ const char *line_size_props[2]; const char *nr_sets_prop; }; /* These are used to index the cache_type_info array. */ #define CACHE_TYPE_UNIFIED 0 /* cache-size, cache-block-size, etc. */ #define CACHE_TYPE_UNIFIED_D 1 /* d-cache-size, d-cache-block-size, etc */ #define CACHE_TYPE_INSTRUCTION 2 #define CACHE_TYPE_DATA 3 static const struct cache_type_info cache_type_info[] = { { /* Embedded systems that use cache-size, cache-block-size, * etc. for the Unified (typically L2) cache. */ .name = "Unified", .size_prop = "cache-size", .line_size_props = { "cache-line-size", "cache-block-size", }, .nr_sets_prop = "cache-sets", }, { /* PowerPC Processor binding says the [di]-cache-* * must be equal on unified caches, so just use * d-cache properties. */ .name = "Unified", .size_prop = "d-cache-size", .line_size_props = { "d-cache-line-size", "d-cache-block-size", }, .nr_sets_prop = "d-cache-sets", }, { .name = "Instruction", .size_prop = "i-cache-size", .line_size_props = { "i-cache-line-size", "i-cache-block-size", }, .nr_sets_prop = "i-cache-sets", }, { .name = "Data", .size_prop = "d-cache-size", .line_size_props = { "d-cache-line-size", "d-cache-block-size", }, .nr_sets_prop = "d-cache-sets", }, }; /* Cache object: each instance of this corresponds to a distinct cache * in the system. There are separate objects for Harvard caches: one * each for instruction and data, and each refers to the same OF node. * The refcount of the OF node is elevated for the lifetime of the * cache object. A cache object is released when its shared_cpu_map * is cleared (see cache_cpu_clear). * * A cache object is on two lists: an unsorted global list * (cache_list) of cache objects; and a singly-linked list * representing the local cache hierarchy, which is ordered by level * (e.g. L1d -> L1i -> L2 -> L3). */ struct cache { struct device_node *ofnode; /* OF node for this cache, may be cpu */ struct cpumask shared_cpu_map; /* online CPUs using this cache */ int type; /* split cache disambiguation */ int level; /* level not explicit in device tree */ int group_id; /* id of the group of threads that share this cache */ struct list_head list; /* global list of cache objects */ struct cache *next_local; /* next cache of >= level */ }; static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu); /* traversal/modification of this list occurs only at cpu hotplug time; * access is serialized by cpu hotplug locking */ static LIST_HEAD(cache_list); static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k) { return container_of(k, struct cache_index_dir, kobj); } static const char *cache_type_string(const struct cache *cache) { return cache_type_info[cache->type].name; } static void cache_init(struct cache *cache, int type, int level, struct device_node *ofnode, int group_id) { cache->type = type; cache->level = level; cache->ofnode = of_node_get(ofnode); cache->group_id = group_id; INIT_LIST_HEAD(&cache->list); list_add(&cache->list, &cache_list); } static struct cache *new_cache(int type, int level, struct device_node *ofnode, int group_id) { struct cache *cache; cache = kzalloc_obj(*cache); if (cache) cache_init(cache, type, level, ofnode, group_id); return cache; } static void release_cache_debugcheck(struct cache *cache) { struct cache *iter; list_for_each_entry(iter, &cache_list, list) WARN_ONCE(iter->next_local == cache, "cache for %pOFP(%s) refers to cache for %pOFP(%s)\n", iter->ofnode, cache_type_string(iter), cache->ofnode, cache_type_string(cache)); } static void release_cache(struct cache *cache) { if (!cache) return; pr_debug("freeing L%d %s cache for %pOFP\n", cache->level, cache_type_string(cache), cache->ofnode); release_cache_debugcheck(cache); list_del(&cache->list); of_node_put(cache->ofnode); kfree(cache); } static void cache_cpu_set(struct cache *cache, int cpu) { struct cache *next = cache; while (next) { WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map), "CPU %i already accounted in %pOFP(%s)\n", cpu, next->ofnode, cache_type_string(next)); cpumask_set_cpu(cpu, &next->shared_cpu_map); next = next->next_local; } } static int cache_size(const struct cache *cache, unsigned int *ret) { const char *propname; const __be32 *cache_size; propname = cache_type_info[cache->type].size_prop; cache_size = of_get_property(cache->ofnode, propname, NULL); if (!cache_size) return -ENODEV; *ret = of_read_number(cache_size, 1); return 0; } static int cache_size_kb(const struct cache *cache, unsigned int *ret) { unsigned int size; if (cache_size(cache, &size)) return -ENODEV; *ret = size / 1024; return 0; } /* not cache_line_size() because that's a macro in include/linux/cache.h */ static int cache_get_line_size(const struct cache *cache, unsigned int *ret) { const __be32 *line_size; int i, lim; lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props); for (i = 0; i < lim; i++) { const char *propname; propname = cache_type_info[cache->type].line_size_props[i]; line_size = of_get_property(cache->ofnode, propname, NULL); if (line_size) break; } if (!line_size) return -ENODEV; *ret = of_read_number(line_size, 1); return 0; } static int cache_nr_sets(const struct cache *cache, unsigned int *ret) { const char *propname; const __be32 *nr_sets; propname = cache_type_info[cache->type].nr_sets_prop; nr_sets = of_get_property(cache->ofnode, propname, NULL); if (!nr_sets) return -ENODEV; *ret = of_read_number(nr_sets, 1); return 0; } static int cache_associativity(const struct cache *cache, unsigned int *ret) { unsigned int line_size; unsigned int nr_sets; unsigned int size; if (cache_nr_sets(cache, &nr_sets)) goto err; /* If the cache is fully associative, there is no need to * check the other properties. */ if (nr_sets == 1) { *ret = 0; return 0; } if (cache_get_line_size(cache, &line_size)) goto err; if (cache_size(cache, &size)) goto err; if (!(nr_sets > 0 && size > 0 && line_size > 0)) goto err; *ret = (size / nr_sets) / line_size; return 0; err: return -ENODEV; } /* helper for dealing with split caches */ static struct cache *cache_find_first_sibling(struct cache *cache) { struct cache *iter; if (cache->type == CACHE_TYPE_UNIFIED || cache->type == CACHE_TYPE_UNIFIED_D) return cache; list_for_each_entry(iter, &cache_list, list) if (iter->ofnode == cache->ofnode && iter->group_id == cache->group_id && iter->next_local == cache) return iter; return cache; } /* return the first cache on a local list matching node and thread-group id */ static struct cache *cache_lookup_by_node_group(const struct device_node *node, int group_id) { struct cache *cache = NULL; struct cache *iter; list_for_each_entry(iter, &cache_list, list) { if (iter->ofnode != node || iter->group_id != group_id) continue; cache = cache_find_first_sibling(iter); break; } return cache; } static bool cache_node_is_unified(const struct device_node *np) { return of_get_property(np, "cache-unified", NULL); } /* * Unified caches can have two different sets of tags. Most embedded * use cache-size, etc. for the unified cache size, but open firmware systems * use d-cache-size, etc. Check on initialization for which type we have, and * return the appropriate structure type. Assume it's embedded if it isn't * open firmware. If it's yet a 3rd type, then there will be missing entries * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need * to be extended further. */ static int cache_is_unified_d(const struct device_node *np) { return of_get_property(np, cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ? CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED; } static struct cache *cache_do_one_devnode_unified(struct device_node *node, int group_id, int level) { pr_debug("creating L%d ucache for %pOFP\n", level, node); return new_cache(cache_is_unified_d(node), level, node, group_id); } static struct cache *cache_do_one_devnode_split(struct device_node *node, int group_id, int level) { struct cache *dcache, *icache; pr_debug("creating L%d dcache and icache for %pOFP\n", level, node); dcache = new_cache(CACHE_TYPE_DATA, level, node, group_id); icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node, group_id); if (!dcache || !icache) goto err; dcache->next_local = icache; return dcache; err: release_cache(dcache); release_cache(icache); return NULL; } static struct cache *cache_do_one_devnode(struct device_node *node, int group_id, int level) { struct cache *cache; if (cache_node_is_unified(node)) cache = cache_do_one_devnode_unified(node, group_id, level); else cache = cache_do_one_devnode_split(node, group_id, level); return cache; } static struct cache *cache_lookup_or_instantiate(struct device_node *node, int group_id, int level) { struct cache *cache; cache = cache_lookup_by_node_group(node, group_id); WARN_ONCE(cache && cache->level != level, "cache level mismatch on lookup (got %d, expected %d)\n", cache->level, level); if (!cache) cache = cache_do_one_devnode(node, group_id, level); return cache; } static void link_cache_lists(struct cache *smaller, struct cache *bigger) { while (smaller->next_local) { if (smaller->next_local == bigger) return; /* already linked */ smaller = smaller->next_local; } smaller->next_local = bigger; /* * The cache->next_local list sorts by level ascending: * L1d -> L1i -> L2 -> L3 ... */ WARN_ONCE((smaller->level == 1 && bigger->level > 2) || (smaller->level > 1 && bigger->level != smaller->level + 1), "linking L%i cache %pOFP to L%i cache %pOFP; skipped a level?\n", smaller->level, smaller->ofnode, bigger->level, bigger->ofnode); } static void do_subsidiary_caches_debugcheck(struct cache *cache) { WARN_ONCE(cache->level != 1, "instantiating cache chain from L%d %s cache for " "%pOFP instead of an L1\n", cache->level, cache_type_string(cache), cache->ofnode); WARN_ONCE(!of_node_is_type(cache->ofnode, "cpu"), "instantiating cache chain from node %pOFP of type '%s' " "instead of a cpu node\n", cache->ofnode, of_node_get_device_type(cache->ofnode)); } /* * If sub-groups of threads in a core containing @cpu_id share the * L@level-cache (information obtained via "ibm,thread-groups" * device-tree property), then we identify the group by the first * thread-sibling in the group. We define this to be the group-id. * * In the absence of any thread-group information for L@level-cache, * this function returns -1. */ static int get_group_id(unsigned int cpu_id, int level) { if (has_big_cores && level == 1) return cpumask_first(per_cpu(thread_group_l1_cache_map, cpu_id)); else if (thread_group_shares_l2 && level == 2) return cpumask_first(per_cpu(thread_group_l2_cache_map, cpu_id)); else if (thread_group_shares_l3 && level == 3) return cpumask_first(per_cpu(thread_group_l3_cache_map, cpu_id)); return -1; } static void do_subsidiary_caches(struct cache *cache, unsigned int cpu_id) { struct device_node *subcache_node; int level = cache->level; do_subsidiary_caches_debugcheck(cache); while ((subcache_node = of_find_next_cache_node(cache->ofnode))) { struct cache *subcache; int group_id; level++; group_id = get_group_id(cpu_id, level); subcache = cache_lookup_or_instantiate(subcache_node, group_id, level); of_node_put(subcache_node); if (!subcache) break; link_cache_lists(cache, subcache); cache = subcache; } }