--- /dev/null
+/*
+ * cacheinfo support - processor cache information via sysfs
+ *
+ * Based on arch/x86/kernel/cpu/intel_cacheinfo.c
+ * Author: Sudeep Holla <sudeep.holla@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#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 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 of_node is already populated */
+ if (this_cpu_ci->info_list->of_node)
+ 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 (np && 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 */
+ this_leaf->of_node = np;
+ index++;
+ }
+ return 0;
+}
+
+static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
+ struct cacheinfo *sib_leaf)
+{
+ return sib_leaf->of_node == this_leaf->of_node;
+}
+#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 systems, assume unique level 1 cache, 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
+
+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;
+
+ ret = cache_setup_of_node(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);
+ }
+ }
+ }
+
+ 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);
+ 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);
+ }
+ of_node_put(this_leaf->of_node);
+ }
+}
+
+static void free_cache_attributes(unsigned int cpu)
+{
+ 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))
+ return -ENOENT;
+
+ per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
+ sizeof(struct cacheinfo), GFP_KERNEL);
+ if (per_cpu_cacheinfo(cpu) == NULL)
+ return -ENOMEM;
+
+ ret = populate_cache_leaves(cpu);
+ if (ret)
+ goto free_ci;
+ /*
+ * For systems using DT for cache hierarcy, of_node 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)
+ 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(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(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_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_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;
+ 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 void cache_remove_dev(unsigned int cpu)
+{
+ if (!cpumask_test_cpu(cpu, &cache_dev_map))
+ return;
+ cpumask_clear_cpu(cpu, &cache_dev_map);
+
+ cpu_cache_sysfs_exit(cpu);
+}
+
+static int cacheinfo_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ int rc = 0;
+
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_ONLINE:
+ rc = detect_cache_attributes(cpu);
+ if (!rc)
+ rc = cache_add_dev(cpu);
+ break;
+ case CPU_DEAD:
+ cache_remove_dev(cpu);
+ if (per_cpu_cacheinfo(cpu))
+ free_cache_attributes(cpu);
+ break;
+ }
+ return notifier_from_errno(rc);
+}
+
+static int __init cacheinfo_sysfs_init(void)
+{
+ int cpu, rc = 0;
+
+ cpu_notifier_register_begin();
+
+ for_each_online_cpu(cpu) {
+ rc = detect_cache_attributes(cpu);
+ if (rc) {
+ pr_err("error detecting cacheinfo..cpu%d\n", cpu);
+ goto out;
+ }
+ rc = cache_add_dev(cpu);
+ if (rc) {
+ free_cache_attributes(cpu);
+ pr_err("error populating cacheinfo..cpu%d\n", cpu);
+ goto out;
+ }
+ }
+ __hotcpu_notifier(cacheinfo_cpu_callback, 0);
+
+out:
+ cpu_notifier_register_done();
+ return rc;
+}
+
+device_initcall(cacheinfo_sysfs_init);
--- /dev/null
+#ifndef _LINUX_CACHEINFO_H
+#define _LINUX_CACHEINFO_H
+
+#include <linux/bitops.h>
+#include <linux/cpumask.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),
+};
+
+/**
+ * struct cacheinfo - represent a cache leaf node
+ * @type: type of the cache - data, inst or unified
+ * @level: represents the hierarcy 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
+ * @of_node: if devicetree is used, this represents either the cpu node in
+ * case there's no explicit cache node or the cache node itself in the
+ * device tree
+ * @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 {
+ 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)
+
+ struct device_node *of_node;
+ bool disable_sysfs;
+ void *priv;
+};
+
+struct cpu_cacheinfo {
+ struct cacheinfo *info_list;
+ unsigned int num_levels;
+ unsigned int num_leaves;
+};
+
+/*
+ * Helpers to make sure "func" is executed on the cpu whose cache
+ * attributes are being detected
+ */
+#define DEFINE_SMP_CALL_CACHE_FUNCTION(func) \
+static inline void _##func(void *ret) \
+{ \
+ int cpu = smp_processor_id(); \
+ *(int *)ret = __##func(cpu); \
+} \
+ \
+int func(unsigned int cpu) \
+{ \
+ int ret; \
+ smp_call_function_single(cpu, _##func, &ret, true); \
+ return ret; \
+}
+
+struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
+int init_cache_level(unsigned int cpu);
+int populate_cache_leaves(unsigned int cpu);
+
+const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);
+
+#endif /* _LINUX_CACHEINFO_H */
projects / linux-beck.git / commitdiff