@@ -224,3 +224,44 @@ Description: Parameters for the Intel P-state driver
frequency range.
More details can be found in Documentation/cpu-freq/intel-pstate.txt
+
+What: /sys/devices/system/cpu/cpu*/cache/index*/<set_of_attributes_mentioned_below>
+Date: June 2014(documented, existed before August 2008)
+Contact: Sudeep Holla <sudeep.holla@arm.com>
+ Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description: Parameters for the CPU cache attributes
+
+ attributes:
+ - writethrough: data is written to both the cache line
+ and to the block in the lower-level memory
+ - writeback: data is written only to the cache line and
+ the modified cache line is written to main
+ memory only when it is replaced
+ - writeallocate: allocate a memory location to a cache line
+ on a cache miss because of a write
+ - readallocate: allocate a memory location to a cache line
+ on a cache miss because of a read
+
+ coherency_line_size: the minimum amount of data that gets transferred
+
+ level: the cache hierarcy in the multi-level cache configuration
+
+ number_of_sets: total number of sets in the cache, a set is a
+ collection of cache lines with the same cache index
+
+ physical_line_partition: number of physical cache line per cache tag
+
+ shared_cpu_list: the list of cpus sharing the cache
+
+ shared_cpu_map: logical cpu mask containing the list of cpus sharing
+ the cache
+
+ size: the total cache size in kB
+
+ type:
+ - instruction: cache that only holds instructions
+ - data: cache that only caches data
+ - unified: cache that holds both data and instructions
+
+ ways_of_associativity: degree of freedom in placing a particular block
+ of memory in the cache
@@ -4,7 +4,7 @@ obj-y := component.o core.o bus.o dd.o syscore.o \
driver.o class.o platform.o \
cpu.o firmware.o init.o map.o devres.o \
attribute_container.o transport_class.o \
- topology.o container.o
+ topology.o container.o cacheinfo.o
obj-$(CONFIG_DEVTMPFS) += devtmpfs.o
obj-$(CONFIG_DMA_CMA) += dma-contiguous.o
obj-y += power/
new file mode 100644
@@ -0,0 +1,564 @@
+/*
+ * 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.
+ */
+#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;
+}
+
+static int of_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;
+ 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;
+}
+#else
+static inline int of_cache_shared_cpu_map_setup(unsigned int cpu)
+{
+ return 0;
+}
+#endif
+
+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);
+ }
+}
+
+int __weak init_cache_level(unsigned int cpu)
+{
+ return -ENOENT;
+}
+
+int __weak populate_cache_leaves(unsigned int cpu)
+{
+ return -ENOENT;
+}
+
+static void free_cache_attributes(unsigned int cpu)
+{
+ cache_shared_cpu_map_remove(cpu);
+
+ kfree(per_cpu_cacheinfo(cpu));
+ per_cpu_cacheinfo(cpu) = NULL;
+}
+
+/*
+ * Helpers to make sure "func" is executed on the cpu whose cache
+ * attributes are being detected
+ */
+#define DEFINE_SMP_CALL_FUNCTION(func) \
+static void _##func(void *ret) \
+{ \
+ int cpu = smp_processor_id(); \
+ *(int *)ret = func(cpu); \
+} \
+static int __##func(unsigned int cpu) \
+{ \
+ int ret; \
+ smp_call_function_single(cpu, _##func, &ret, true); \
+ return ret; \
+}
+DEFINE_SMP_CALL_FUNCTION(init_cache_level)
+DEFINE_SMP_CALL_FUNCTION(populate_cache_leaves)
+
+static int detect_cache_attributes(unsigned int cpu)
+{
+ int ret;
+
+ if (__init_cache_level(cpu))
+ return -ENOENT;
+
+ per_cpu_cacheinfo(cpu) = kzalloc(sizeof(struct cacheinfo) *
+ cache_leaves(cpu), 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. Otherwise populate_cache_leaves needs to set
+ * shared_cpu_map and next-level-cache should not be specified in DT
+ */
+ ret = of_cache_shared_cpu_map_setup(cpu);
+ if (ret)
+ goto free_ci;
+ return 0;
+
+free_ci:
+ free_cache_attributes(cpu);
+ return ret;
+}
+
+#ifdef CONFIG_SYSFS
+
+/* 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); \
+ if (!this_leaf->object) \
+ return -EINVAL; \
+ 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);
+
+static ssize_t ways_of_associativity_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct cacheinfo *this_leaf = dev_get_drvdata(dev);
+
+ /* will be zero for fully associative cache, but check for size */
+ if (!this_leaf->size)
+ return -EINVAL;
+ return sprintf(buf, "%u\n", this_leaf->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);
+
+ if (!this_leaf->size)
+ return -EINVAL;
+ return sprintf(buf, "%uK\n", this_leaf->size >> 10);
+}
+
+static ssize_t shared_cpumap_show_func(struct device *dev, int type, char *buf)
+{
+ struct cacheinfo *this_leaf = dev_get_drvdata(dev);
+ 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 ssize_t shared_cpu_map_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return shared_cpumap_show_func(dev, 0, buf);
+}
+
+static ssize_t shared_cpu_list_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return shared_cpumap_show_func(dev, 1, 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 attributes_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;
+ ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf - 2;
+ int n = 0;
+
+ if (!ci_attr)
+ return -EINVAL;
+
+ if (ci_attr & CACHE_WRITE_THROUGH)
+ n += snprintf(buf + n, len - n, "WriteThrough\n");
+ if (ci_attr & CACHE_WRITE_BACK)
+ n += snprintf(buf + n, len - n, "WriteBack\n");
+ if (ci_attr & CACHE_READ_ALLOCATE)
+ n += snprintf(buf + n, len - n, "ReadAllocate\n");
+ if (ci_attr & CACHE_WRITE_ALLOCATE)
+ n += snprintf(buf + n, len - n, "WriteAllocate\n");
+ buf[n] = '\0';
+ 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(attributes);
+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,
+ NULL
+};
+
+ATTRIBUTE_GROUPS(cache_default);
+
+static const struct device_attribute *cache_optional_attrs[] = {
+ &dev_attr_coherency_line_size,
+ &dev_attr_ways_of_associativity,
+ &dev_attr_number_of_sets,
+ &dev_attr_size,
+ &dev_attr_attributes,
+ &dev_attr_physical_line_partition,
+ NULL
+};
+
+static int device_add_attrs(struct device *dev,
+ const struct device_attribute **dev_attrs)
+{
+ int i, error = 0;
+ struct device_attribute *dev_attr;
+ char *buf;
+
+ if (!dev_attrs)
+ return 0;
+
+ buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ for (i = 0; dev_attrs[i]; i++) {
+ dev_attr = (struct device_attribute *)dev_attrs[i];
+
+ /* create attributes that provides meaningful value */
+ if (dev_attr->show(dev, dev_attr, buf) < 0)
+ continue;
+
+ error = device_create_file(dev, dev_attrs[i]);
+ if (error) {
+ while (--i >= 0)
+ device_remove_file(dev, dev_attrs[i]);
+ break;
+ }
+ }
+
+ kfree(buf);
+ return error;
+}
+
+static void device_remove_attrs(struct device *dev,
+ const struct device_attribute **dev_attrs)
+{
+ int i;
+
+ if (!dev_attrs)
+ return;
+
+ for (i = 0; dev_attrs[i]; dev_attrs++, i++)
+ device_remove_file(dev, dev_attrs[i]);
+}
+
+const struct device_attribute **
+__weak cache_get_priv_attr(struct device *cache_idx_dev)
+{
+ return NULL;
+}
+
+/* Add/Remove cache interface for CPU device */
+static void cpu_cache_sysfs_exit(unsigned int cpu)
+{
+ int i;
+ struct device *tmp_dev;
+ const struct device_attribute **ci_priv_attr;
+
+ if (per_cpu_index_dev(cpu)) {
+ for (i = 0; i < cache_leaves(cpu); i++) {
+ tmp_dev = per_cache_index_dev(cpu, i);
+ if (!tmp_dev)
+ continue;
+ ci_priv_attr = cache_get_priv_attr(tmp_dev);
+ device_remove_attrs(tmp_dev, ci_priv_attr);
+ device_remove_attrs(tmp_dev, cache_optional_attrs);
+ device_unregister(tmp_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) = device_create(dev->class, dev, cpu,
+ NULL, "cache");
+ if (IS_ERR_OR_NULL(per_cpu_cache_dev(cpu)))
+ return PTR_ERR(per_cpu_cache_dev(cpu));
+
+ /* Allocate all required memory */
+ per_cpu_index_dev(cpu) = kzalloc(sizeof(struct device *) *
+ cache_leaves(cpu), 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 short i;
+ int rc;
+ struct device *tmp_dev, *parent;
+ struct cacheinfo *this_leaf;
+ const struct device_attribute **ci_priv_attr;
+ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+
+ 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;
+ tmp_dev = device_create_with_groups(parent->class, parent, i,
+ this_leaf,
+ cache_default_groups,
+ "index%1u", i);
+ if (IS_ERR_OR_NULL(tmp_dev)) {
+ rc = PTR_ERR(tmp_dev);
+ goto err;
+ }
+
+ rc = device_add_attrs(tmp_dev, cache_optional_attrs);
+ if (unlikely(rc))
+ goto err;
+
+ ci_priv_attr = cache_get_priv_attr(tmp_dev);
+ rc = device_add_attrs(tmp_dev, ci_priv_attr);
+ if (unlikely(rc))
+ goto err;
+
+ per_cache_index_dev(cpu, i) = tmp_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) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ rc = detect_cache_attributes(cpu);
+ if (!rc)
+ rc = cache_add_dev(cpu);
+ break;
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ 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);
+
+#endif /* CONFIG_SYSFS */
new file mode 100644
@@ -0,0 +1,56 @@
+#ifndef _LINUX_CACHEINFO_H
+#define _LINUX_CACHEINFO_H
+
+#include <linux/bitops.h>
+#include <linux/compiler.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/sysfs.h>
+
+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 {
+ /* core properties */
+ enum cache_type type; /* data, inst or unified */
+ unsigned int level;
+ unsigned int coherency_line_size; /* cache line size */
+ unsigned int number_of_sets; /* no. of sets per way */
+ unsigned int ways_of_associativity; /* no. of ways */
+ unsigned int physical_line_partition; /* no. of lines per tag */
+ unsigned int size; /* total cache size */
+ cpumask_t shared_cpu_map;
+ unsigned int attributes;
+#define CACHE_WRITE_THROUGH BIT(0)
+#define CACHE_WRITE_BACK BIT(1)
+#define CACHE_READ_ALLOCATE BIT(2)
+#define CACHE_WRITE_ALLOCATE BIT(3)
+
+ /* book keeping */
+ struct device_node *of_node; /* cpu if no explicit cache node */
+ bool disable_sysfs; /* don't expose this leaf through sysfs */
+ void *priv;
+};
+
+struct cpu_cacheinfo {
+ struct cacheinfo *info_list;
+ unsigned int num_levels;
+ unsigned int num_leaves;
+};
+
+struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
+int init_cache_level(unsigned int cpu);
+int populate_cache_leaves(unsigned int cpu);
+
+#ifdef CONFIG_SYSFS
+const struct device_attribute **
+cache_get_priv_attr(struct device *cache_idx_dev);
+#endif
+
+#endif /* _LINUX_CACHEINFO_H */