@@ -1,5 +1,7 @@
/*
* ARM cacheinfo support
+ * - Processor cache information interface to userspace via sysfs
+ * - Based on intel cacheinfo implementation
*
* Copyright (C) 2013 ARM Ltd.
* All Rights Reserved
@@ -14,10 +16,12 @@
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/init.h>
+#include <linux/kobject.h>
#include <linux/of.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp.h>
+#include <linux/sysfs.h>
#include <asm/outercache.h>
#include <asm/processor.h>
@@ -369,3 +373,315 @@ static void free_cache_attributes(unsigned int cpu)
kfree(per_cpu_cacheinfo(cpu));
per_cpu_cacheinfo(cpu) = NULL;
}
+
+#ifdef CONFIG_SYSFS
+
+struct cache_attr {
+ struct attribute attr;
+ ssize_t(*show) (struct cpu_cacheinfo *, char *, unsigned int);
+ ssize_t(*store) (struct cpu_cacheinfo *, const char *, size_t count,
+ unsigned int);
+};
+
+/* pointer to kobject for cpuX/cache */
+static DEFINE_PER_CPU(struct kobject *, ci_cache_kobject);
+#define per_cpu_cache_kobject(cpu) (per_cpu(ci_cache_kobject, cpu))
+
+struct index_kobject {
+ struct kobject kobj;
+ unsigned int cpu;
+ unsigned short index;
+};
+
+static cpumask_t cache_dev_map;
+
+/* pointer to array of kobjects for cpuX/cache/indexY */
+static DEFINE_PER_CPU(struct index_kobject *, ci_index_kobject);
+#define per_cpu_index_kobject(cpu) (per_cpu(ci_index_kobject, cpu))
+#define INDEX_KOBJECT_PTR(cpu, idx) (&((per_cpu_index_kobject(cpu))[idx]))
+
+#define show_one_plus(file_name, object) \
+static ssize_t show_##file_name(struct cpu_cacheinfo *this_leaf, \
+ char *buf, unsigned int cpu) \
+{ \
+ return sprintf(buf, "%lu\n", (unsigned long)this_leaf->object); \
+}
+
+show_one_plus(level, info.level);
+show_one_plus(coherency_line_size, info.coherency_line_size);
+show_one_plus(ways_of_associativity, info.ways_of_associativity);
+show_one_plus(number_of_sets, info.number_of_sets);
+
+static ssize_t show_size(struct cpu_cacheinfo *this_leaf, char *buf,
+ unsigned int cpu)
+{
+ return sprintf(buf, "%dK\n", this_leaf->info.size / 1024);
+}
+
+static ssize_t show_shared_cpu_map_func(struct cpu_cacheinfo *this_leaf,
+ int type, char *buf)
+{
+ ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
+ int n = 0;
+
+ if (len > 1) {
+ const struct cpumask *mask = &this_leaf->shared_cpu_map;
+ n = type ?
+ cpulist_scnprintf(buf, len - 2, mask) :
+ cpumask_scnprintf(buf, len - 2, mask);
+ buf[n++] = '\n';
+ buf[n] = '\0';
+ }
+ return n;
+}
+
+static inline ssize_t show_shared_cpu_map(struct cpu_cacheinfo *leaf, char *buf,
+ unsigned int cpu)
+{
+ return show_shared_cpu_map_func(leaf, 0, buf);
+}
+
+static inline ssize_t show_shared_cpu_list(struct cpu_cacheinfo *leaf,
+ char *buf, unsigned int cpu)
+{
+ return show_shared_cpu_map_func(leaf, 1, buf);
+}
+
+static ssize_t show_type(struct cpu_cacheinfo *this_leaf, char *buf,
+ unsigned int cpu)
+{
+ switch (this_leaf->info.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 sprintf(buf, "Unknown\n");
+ }
+}
+
+#define to_object(k) container_of(k, struct index_kobject, kobj)
+#define to_attr(a) container_of(a, struct cache_attr, attr)
+
+#define define_one_ro(_name) \
+static struct cache_attr _name = \
+ __ATTR(_name, 0444, show_##_name, NULL)
+
+define_one_ro(level);
+define_one_ro(type);
+define_one_ro(coherency_line_size);
+define_one_ro(ways_of_associativity);
+define_one_ro(number_of_sets);
+define_one_ro(size);
+define_one_ro(shared_cpu_map);
+define_one_ro(shared_cpu_list);
+
+static struct attribute *default_attrs[] = {
+ &type.attr,
+ &level.attr,
+ &coherency_line_size.attr,
+ &ways_of_associativity.attr,
+ &number_of_sets.attr,
+ &size.attr,
+ &shared_cpu_map.attr,
+ &shared_cpu_list.attr,
+ NULL
+};
+
+static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
+{
+ struct cache_attr *fattr = to_attr(attr);
+ struct index_kobject *this_leaf = to_object(kobj);
+ ssize_t ret;
+
+ ret = fattr->show ?
+ fattr->show(CPU_CACHEINFO_IDX(this_leaf->cpu, this_leaf->index),
+ buf, this_leaf->cpu) : 0;
+ return ret;
+}
+
+static ssize_t store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ struct cache_attr *fattr = to_attr(attr);
+ struct index_kobject *leaf_ptr = to_object(kobj);
+ ssize_t ret;
+
+ ret = fattr->store ?
+ fattr->store(CPU_CACHEINFO_IDX(leaf_ptr->cpu, leaf_ptr->index),
+ buf, count, leaf_ptr->cpu) : 0;
+ return ret;
+}
+
+static const struct sysfs_ops sysfs_ops = {
+ .show = show,
+ .store = store,
+};
+
+static struct kobj_type ktype_cache = {
+ .sysfs_ops = &sysfs_ops,
+ .default_attrs = default_attrs,
+};
+
+static struct kobj_type ktype_percpu_entry = {
+ .sysfs_ops = &sysfs_ops,
+};
+
+static void cpu_cache_sysfs_exit(unsigned int cpu)
+{
+ kfree(per_cpu_cache_kobject(cpu));
+ kfree(per_cpu_index_kobject(cpu));
+ per_cpu_cache_kobject(cpu) = NULL;
+ per_cpu_index_kobject(cpu) = NULL;
+}
+
+static int cpu_cache_sysfs_init(unsigned int cpu)
+{
+ if (per_cpu_cacheinfo(cpu) == NULL)
+ return -ENOENT;
+
+ /* Allocate all required memory */
+ per_cpu_cache_kobject(cpu) =
+ kzalloc(sizeof(struct kobject), GFP_KERNEL);
+ if (unlikely(per_cpu_cache_kobject(cpu) == NULL))
+ goto err_out;
+
+ per_cpu_index_kobject(cpu) =
+ kzalloc(sizeof(struct index_kobject) * cache_leaves(cpu),
+ GFP_KERNEL);
+ if (unlikely(per_cpu_index_kobject(cpu) == NULL))
+ goto err_out;
+
+ return 0;
+
+err_out:
+ cpu_cache_sysfs_exit(cpu);
+ return -ENOMEM;
+}
+
+static void _detect_cache_attributes(void *_retval)
+{
+ int cpu = smp_processor_id();
+ *(int *)_retval = detect_cache_attributes(cpu);
+}
+
+/* Add/Remove cache interface for CPU device */
+static int cache_add_dev(struct device *dev)
+{
+ unsigned int cpu = dev->id;
+ unsigned long i, j;
+ struct index_kobject *this_object;
+ int retval;
+
+ smp_call_function_single(cpu, _detect_cache_attributes, &retval, true);
+ if (retval) {
+ pr_err("error populating cacheinfo..cpu%d\n", cpu);
+ return retval;
+ }
+ retval = cpu_cache_sysfs_init(cpu);
+ if (unlikely(retval < 0))
+ return retval;
+
+ retval = kobject_init_and_add(per_cpu_cache_kobject(cpu),
+ &ktype_percpu_entry,
+ &dev->kobj, "%s", "cache");
+ if (retval < 0) {
+ cpu_cache_sysfs_exit(cpu);
+ return retval;
+ }
+
+ for (i = 0; i < cache_leaves(cpu); i++) {
+ this_object = INDEX_KOBJECT_PTR(cpu, i);
+ this_object->cpu = cpu;
+ this_object->index = i;
+
+ retval = kobject_init_and_add(&(this_object->kobj),
+ &ktype_cache,
+ per_cpu_cache_kobject(cpu),
+ "index%1lu", i);
+ if (unlikely(retval)) {
+ for (j = 0; j < i; j++)
+ kobject_put(&(INDEX_KOBJECT_PTR(cpu, j)->kobj));
+ kobject_put(per_cpu_cache_kobject(cpu));
+ cpu_cache_sysfs_exit(cpu);
+ return retval;
+ }
+ kobject_uevent(&(this_object->kobj), KOBJ_ADD);
+ }
+ cpumask_set_cpu(cpu, &cache_dev_map);
+
+ kobject_uevent(per_cpu_cache_kobject(cpu), KOBJ_ADD);
+ return 0;
+}
+
+static void cache_remove_dev(struct device *dev)
+{
+ unsigned int cpu = dev->id;
+ unsigned long i;
+
+ if (!cpumask_test_cpu(cpu, &cache_dev_map))
+ return;
+ cpumask_clear_cpu(cpu, &cache_dev_map);
+
+ for (i = 0; i < cache_leaves(cpu); i++)
+ kobject_put(&(INDEX_KOBJECT_PTR(cpu, i)->kobj));
+ kobject_put(per_cpu_cache_kobject(cpu));
+ cpu_cache_sysfs_exit(cpu);
+
+ free_cache_attributes(cpu);
+}
+
+static int cacheinfo_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ struct device *dev = get_cpu_device(cpu);
+ int ret;
+
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ ret = cache_add_dev(dev);
+ if (ret)
+ /* must not fail so can't use NOTIFY_BAD */
+ return NOTIFY_STOP;
+ break;
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ cache_remove_dev(dev);
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block cacheinfo_cpu_notifier = {
+ .notifier_call = cacheinfo_cpu_callback,
+};
+
+static int __init cache_info_init(void)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ int ret;
+ struct device *dev = get_cpu_device(cpu);
+ if (!dev) {
+ pr_err("No cpu device for CPU %d..skipping\n", cpu);
+ return -ENODEV;
+ }
+
+ ret = cache_add_dev(dev);
+ if (ret) {
+ pr_err("error populating cacheinfo..cpu%d\n", cpu);
+ return ret;
+ }
+ }
+ register_hotcpu_notifier(&cacheinfo_cpu_notifier);
+ return 0;
+}
+
+device_initcall(cache_info_init);
+
+#endif /* CONFIG_SYSFS */