// SPDX-License-Identifier: GPL-2.0 /* * cacheinfo support - processor cache information via sysfs * * Based on arch/x86/kernel/cpu/intel_cacheinfo.c * Author: Sudeep Holla <sudeep.holla@arm.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/acpi.h> #include <linux/bitops.h> #include <linux/cacheinfo.h> #include <linux/compiler.h> #include <linux/cpu.h> #include <linux/device.h> #include <linux/init.h> #include <linux/of.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/smp.h> #include <linux/sysfs.h> /* pointer to per cpu cacheinfo */ static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo); #define ci_cacheinfo(cpu) (&per_cpu(ci_cpu_cacheinfo, cpu)) #define cache_leaves(cpu) (ci_cacheinfo(cpu)->num_leaves) #define per_cpu_cacheinfo(cpu) (ci_cacheinfo(cpu)->info_list) struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu) { return ci_cacheinfo(cpu); } #ifdef CONFIG_OF static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, struct cacheinfo *sib_leaf) { return sib_leaf->fw_token == this_leaf->fw_token; } /* OF properties to query for a given cache type */ struct cache_type_info { const char *size_prop; const char *line_size_props[2]; const char *nr_sets_prop; }; static const struct cache_type_info cache_type_info[] = { { .size_prop = "cache-size", .line_size_props = { "cache-line-size", "cache-block-size", }, .nr_sets_prop = "cache-sets", }, { .size_prop = "i-cache-size", .line_size_props = { "i-cache-line-size", "i-cache-block-size", }, .nr_sets_prop = "i-cache-sets", }, { .size_prop = "d-cache-size", .line_size_props = { "d-cache-line-size", "d-cache-block-size", }, .nr_sets_prop = "d-cache-sets", }, }; static inline int get_cacheinfo_idx(enum cache_type type) { if (type == CACHE_TYPE_UNIFIED) return 0; return type; } static void cache_size(struct cacheinfo *this_leaf, struct device_node *np) { const char *propname; int ct_idx; ct_idx = get_cacheinfo_idx(this_leaf->type); propname = cache_type_info[ct_idx].size_prop; of_property_read_u32(np, propname, &this_leaf->size); } /* not cache_line_size() because that's a macro in include/linux/cache.h */ static void cache_get_line_size(struct cacheinfo *this_leaf, struct device_node *np) { int i, lim, ct_idx; ct_idx = get_cacheinfo_idx(this_leaf->type); lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props); for (i = 0; i < lim; i++) { int ret; u32 line_size; const char *propname; propname = cache_type_info[ct_idx].line_size_props[i]; ret = of_property_read_u32(np, propname, &line_size); if (!ret) { this_leaf->coherency_line_size = line_size; break; } } } static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np) { const char *propname; int ct_idx; ct_idx = get_cacheinfo_idx(this_leaf->type); propname = cache_type_info[ct_idx].nr_sets_prop; of_property_read_u32(np, propname, &this_leaf->number_of_sets); } static void cache_associativity(struct cacheinfo *this_leaf) { unsigned int line_size = this_leaf->coherency_line_size; unsigned int nr_sets = this_leaf->number_of_sets; unsigned int size = this_leaf->size; /* * If the cache is fully associative, there is no need to * check the other properties. */ if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0)) this_leaf->ways_of_associativity = (size / nr_sets) / line_size; } static bool cache_node_is_unified(struct cacheinfo *this_leaf, struct device_node *np) { return of_property_read_bool(np, "cache-unified"); } static void cache_of_set_props(struct cacheinfo *this_leaf, struct device_node *np) { /* * init_cache_level must setup the cache level correctly * overriding the architecturally specified levels, so * if type is NONE at this stage, it should be unified */ if (this_leaf->type == CACHE_TYPE_NOCACHE && cache_node_is_unified(this_leaf, np)) this_leaf->type = CACHE_TYPE_UNIFIED; cache_size(this_leaf, np); cache_get_line_size(this_leaf, np); cache_nr_sets(this_leaf, np); cache_associativity(this_leaf); } static int cache_setup_of_node(unsigned int cpu) { struct device_node *np; struct cacheinfo *this_leaf; struct device *cpu_dev = get_cpu_device(cpu); struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); unsigned int index = 0; /* skip if fw_token is already populated */ if (this_cpu_ci->info_list->fw_token) { return 0; } if (!cpu_dev) { pr_err("No cpu device for CPU %d\n", cpu); return -ENODEV; } np = cpu_dev->of_node; if (!np) { pr_err("Failed to find cpu%d device node\n", cpu); return -ENOENT; } while (index < cache_leaves(cpu)) { this_leaf = this_cpu_ci->info_list + index; if (this_leaf->level != 1) np = of_find_next_cache_node(np); else np = of_node_get(np);/* cpu node itself */ if (!np) break; cache_of_set_props(this_leaf, np); this_leaf->fw_token = np; index++; } if (index != cache_leaves(cpu)) /* not all OF nodes populated */ return -ENOENT; return 0; } #else static inline int cache_setup_of_node(unsigned int cpu) { return 0; } static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, struct cacheinfo *sib_leaf) { /* * For non-DT/ACPI systems, assume unique level 1 caches, system-wide * shared caches for all other levels. This will be used only if * arch specific code has not populated shared_cpu_map */ return !(this_leaf->level == 1); } #endif int __weak cache_setup_acpi(unsigned int cpu) { return -ENOTSUPP; } unsigned int coherency_max_size; static int cache_shared_cpu_map_setup(unsigned int cpu) { struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); struct cacheinfo *this_leaf, *sib_leaf; unsigned int index; int ret = 0; if (this_cpu_ci->cpu_map_populated) return 0; if (of_have_populated_dt()) ret = cache_setup_of_node(cpu); else if (!acpi_disabled) ret = cache_setup_acpi(cpu); if (ret) return ret; for (index = 0; index < cache_leaves(cpu); 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) continue;/* skip if itself or no cacheinfo */ sib_leaf = sib_cpu_ci->info_list + index; 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); } } /* record the maximum cache line size */ if (this_leaf->coherency_line_size > coherency_max_size) coherency_max_size = this_leaf->coherency_line_size; } return 0; } static void cache_shared_cpu_map_remove(unsigned int cpu) { struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); struct cacheinfo *this_leaf, *sib_leaf; unsigned int sibling, index; for (index = 0; index < cache_leaves(cpu); index++) { this_leaf = this_cpu_ci->info_list + index; for_each_cpu(sibling, &this_leaf->shared_cpu_map) { struct cpu_cacheinfo *sib_cpu_ci; if (sibling == cpu) /* skip itself */ continue; sib_cpu_ci = get_cpu_cacheinfo(sibling); if (!sib_cpu_ci->info_list) continue; sib_leaf = sib_cpu_ci->info_list + index; cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); } if (of_have_populated_dt()) of_node_put(this_leaf->fw_token); } } static void free_cache_attributes(unsigned int cpu) { if (!per_cpu_cacheinfo(cpu)) return; cache_shared_cpu_map_remove(cpu); kfree(per_cpu_cacheinfo(cpu)); per_cpu_cacheinfo(cpu) = NULL; } int __weak init_cache_level(unsigned int cpu) { return -ENOENT; } int __weak populate_cache_leaves(unsigned int cpu) { return -ENOENT; } static int detect_cache_attributes(unsigned int cpu) { int ret; if (init_cache_level(cpu) || !cache_leaves(cpu)) return -ENOENT; per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), sizeof(struct cacheinfo), GFP_KERNEL); if (per_cpu_cacheinfo(cpu) == NULL) return -ENOMEM; /* * populate_cache_leaves() may completely setup the cache leaves and * shared_cpu_map or it may leave it partially setup. */ ret = populate_cache_leaves(cpu); if (ret) goto free_ci; /* * For systems using DT for cache hierarchy, fw_token * and shared_cpu_map will be set up here only if they are * not populated already */ ret = cache_shared_cpu_map_setup(cpu); if (ret) { pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu); goto free_ci; } return 0; free_ci: free_cache_attributes(cpu); return ret; } /* pointer to cpuX/cache device */ static DEFINE_PER_CPU(struct device *, ci_cache_dev); #define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu)) static cpumask_t cache_dev_map; /* pointer to array of devices for cpuX/cache/indexY */ static DEFINE_PER_CPU(struct device **, ci_index_dev); #define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu)) #define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx]) #define show_one(file_name, object) \ static ssize_t file_name##_show(struct device *dev, \ struct device_attribute *attr, char *buf) \ { \ struct cacheinfo *this_leaf = dev_get_drvdata(dev); \ return sprintf(buf, "%u\n", this_leaf->object); \ } show_one(id, id); show_one(level, level); show_one(coherency_line_size, coherency_line_size); show_one(number_of_sets, number_of_sets); show_one(physical_line_partition, physical_line_partition); show_one(ways_of_associativity, ways_of_associativity); static ssize_t size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct cacheinfo *this_leaf = dev_get_drvdata(dev); return sprintf(buf, "%uK\n", this_leaf->size >> 10); } static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf) { struct cacheinfo *this_leaf = dev_get_drvdata(dev); const struct cpumask *mask = &this_leaf->shared_cpu_map; return cpumap_print_to_pagebuf(list, buf, mask); } static ssize_t shared_cpu_map_show(struct device *dev, struct device_attribute *attr, char *buf) { return shared_cpumap_show_func(dev, false, buf); } static ssize_t shared_cpu_list_show(struct device *dev, struct device_attribute *attr, char *buf) { return shared_cpumap_show_func(dev, true, buf); } static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct cacheinfo *this_leaf = dev_get_drvdata(dev); switch (this_leaf->type) { case CACHE_TYPE_DATA: return sprintf(buf, "Data\n"); case CACHE_TYPE_INST: return sprintf(buf, "Instruction\n"); case CACHE_TYPE_UNIFIED: return sprintf(buf, "Unified\n"); default: return -EINVAL; } } static ssize_t allocation_policy_show(struct device *dev, struct device_attribute *attr, char *buf) { struct cacheinfo *this_leaf = dev_get_drvdata(dev); unsigned int ci_attr = this_leaf->attributes; int n = 0; if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE)) n = sprintf(buf, "ReadWriteAllocate\n"); else if (ci_attr & CACHE_READ_ALLOCATE) n = sprintf(buf, "ReadAllocate\n"); else if (ci_attr & CACHE_WRITE_ALLOCATE) n = sprintf(buf, "WriteAllocate\n"); return n; } static ssize_t write_policy_show(struct device *dev, struct device_attribute *attr, char *buf) { struct cacheinfo *this_leaf = dev_get_drvdata(dev); unsigned int ci_attr = this_leaf->attributes; int n = 0; if (ci_attr & CACHE_WRITE_THROUGH) n = sprintf(buf, "WriteThrough\n"); else if (ci_attr & CACHE_WRITE_BACK) n = sprintf(buf, "WriteBack\n"); return n; } static DEVICE_ATTR_RO(id); static DEVICE_ATTR_RO(level); static DEVICE_ATTR_RO(type); static DEVICE_ATTR_RO(coherency_line_size); static DEVICE_ATTR_RO(ways_of_associativity); static DEVICE_ATTR_RO(number_of_sets); static DEVICE_ATTR_RO(size); static DEVICE_ATTR_RO(allocation_policy); static DEVICE_ATTR_RO(write_policy); static DEVICE_ATTR_RO(shared_cpu_map); static DEVICE_ATTR_RO(shared_cpu_list); static DEVICE_ATTR_RO(physical_line_partition); static struct attribute *cache_default_attrs[] = { &dev_attr_id.attr, &dev_attr_type.attr, &dev_attr_level.attr, &dev_attr_shared_cpu_map.attr, &dev_attr_shared_cpu_list.attr, &dev_attr_coherency_line_size.attr, &dev_attr_ways_of_associativity.attr, &dev_attr_number_of_sets.attr, &dev_attr_size.attr, &dev_attr_allocation_policy.attr, &dev_attr_write_policy.attr, &dev_attr_physical_line_partition.attr, NULL }; static umode_t cache_default_attrs_is_visible(struct kobject *kobj, struct attribute *attr, int unused) { struct device *dev = kobj_to_dev(kobj); struct cacheinfo *this_leaf = dev_get_drvdata(dev); const struct cpumask *mask = &this_leaf->shared_cpu_map; umode_t mode = attr->mode; if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID)) return mode; if ((attr == &dev_attr_type.attr) && this_leaf->type) return mode; if ((attr == &dev_attr_level.attr) && this_leaf->level) return mode; if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask)) return mode; if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask)) return mode; if ((attr == &dev_attr_coherency_line_size.attr) && this_leaf->coherency_line_size) return mode; if ((attr == &dev_attr_ways_of_associativity.attr) && this_leaf->size) /* allow 0 = full associativity */ return mode; if ((attr == &dev_attr_number_of_sets.attr) && this_leaf->number_of_sets) return mode; if ((attr == &dev_attr_size.attr) && this_leaf->size) return mode; if ((attr == &dev_attr_write_policy.attr) && (this_leaf->attributes & CACHE_WRITE_POLICY_MASK)) return mode; if ((attr == &dev_attr_allocation_policy.attr) && (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK)) return mode; if ((attr == &dev_attr_physical_line_partition.attr) && this_leaf->physical_line_partition) return mode; return 0; } static const struct attribute_group cache_default_group = { .attrs = cache_default_attrs, .is_visible = cache_default_attrs_is_visible, }; static const struct attribute_group *cache_default_groups[] = { &cache_default_group, NULL, }; static const struct attribute_group *cache_private_groups[] = { &cache_default_group, NULL, /* Place holder for private group */ NULL, }; const struct attribute_group * __weak cache_get_priv_group(struct cacheinfo *this_leaf) { return NULL; } static const struct attribute_group ** cache_get_attribute_groups(struct cacheinfo *this_leaf) { const struct attribute_group *priv_group = cache_get_priv_group(this_leaf); if (!priv_group) return cache_default_groups; if (!cache_private_groups[1]) cache_private_groups[1] = priv_group; return cache_private_groups; } /* Add/Remove cache interface for CPU device */ static void cpu_cache_sysfs_exit(unsigned int cpu) { int i; struct device *ci_dev; if (per_cpu_index_dev(cpu)) { for (i = 0; i < cache_leaves(cpu); i++) { ci_dev = per_cache_index_dev(cpu, i); if (!ci_dev) continue; device_unregister(ci_dev); } kfree(per_cpu_index_dev(cpu)); per_cpu_index_dev(cpu) = NULL; } device_unregister(per_cpu_cache_dev(cpu)); per_cpu_cache_dev(cpu) = NULL; } static int cpu_cache_sysfs_init(unsigned int cpu) { struct device *dev = get_cpu_device(cpu); if (per_cpu_cacheinfo(cpu) == NULL) return -ENOENT; per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache"); if (IS_ERR(per_cpu_cache_dev(cpu))) return PTR_ERR(per_cpu_cache_dev(cpu)); /* Allocate all required memory */ per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu), sizeof(struct device *), GFP_KERNEL); if (unlikely(per_cpu_index_dev(cpu) == NULL)) goto err_out; return 0; err_out: cpu_cache_sysfs_exit(cpu); return -ENOMEM; } static int cache_add_dev(unsigned int cpu) { unsigned int i; int rc; struct device *ci_dev, *parent; struct cacheinfo *this_leaf; struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); const struct attribute_group **cache_groups; rc = cpu_cache_sysfs_init(cpu); if (unlikely(rc < 0)) return rc; parent = per_cpu_cache_dev(cpu); for (i = 0; i < cache_leaves(cpu); i++) { this_leaf = this_cpu_ci->info_list + i; if (this_leaf->disable_sysfs) continue; if (this_leaf->type == CACHE_TYPE_NOCACHE) break; cache_groups = cache_get_attribute_groups(this_leaf); ci_dev = cpu_device_create(parent, this_leaf, cache_groups, "index%1u", i); if (IS_ERR(ci_dev)) { rc = PTR_ERR(ci_dev); goto err; } per_cache_index_dev(cpu, i) = ci_dev; } cpumask_set_cpu(cpu, &cache_dev_map); return 0; err: cpu_cache_sysfs_exit(cpu); return rc; } static int cacheinfo_cpu_online(unsigned int cpu) { int rc = detect_cache_attributes(cpu); if (rc) return rc; rc = cache_add_dev(cpu); if (rc) free_cache_attributes(cpu); return rc; } static int cacheinfo_cpu_pre_down(unsigned int cpu) { if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map)) cpu_cache_sysfs_exit(cpu); free_cache_attributes(cpu); return 0; } static int __init cacheinfo_sysfs_init(void) { return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE, "base/cacheinfo:online", cacheinfo_cpu_online, cacheinfo_cpu_pre_down); } device_initcall(cacheinfo_sysfs_init);