Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 742 insertions, 0 deletions

diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
new file mode 100644
index 000000000..26e13887a
--- /dev/null
+++ b/drivers/base/cacheinfo.c
@@ -0,0 +1,742 @@
+// 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_device.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)
+#define per_cpu_cacheinfo_idx(cpu, idx)		\
+				(per_cpu_cacheinfo(cpu) + (idx))
+
+struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
+{
+	return ci_cacheinfo(cpu);
+}
+
+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.
+	 */
+	if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)))
+		return (this_leaf->level != 1) && (sib_leaf->level != 1);
+
+	if ((sib_leaf->attributes & CACHE_ID) &&
+	    (this_leaf->attributes & CACHE_ID))
+		return sib_leaf->id == this_leaf->id;
+
+	return sib_leaf->fw_token == this_leaf->fw_token;
+}
+
+bool last_level_cache_is_valid(unsigned int cpu)
+{
+	struct cacheinfo *llc;
+
+	if (!cache_leaves(cpu))
+		return false;
+
+	llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
+
+	return (llc->attributes & CACHE_ID) || !!llc->fw_token;
+
+}
+
+bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
+{
+	struct cacheinfo *llc_x, *llc_y;
+
+	if (!last_level_cache_is_valid(cpu_x) ||
+	    !last_level_cache_is_valid(cpu_y))
+		return false;
+
+	llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1);
+	llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1);
+
+	return cache_leaves_are_shared(llc_x, llc_y);
+}
+
+#ifdef CONFIG_OF
+/* 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;
+	unsigned int index = 0;
+
+	np = of_cpu_device_node_get(cpu);
+	if (!np) {
+		pr_err("Failed to find cpu%d device node\n", cpu);
+		return -ENOENT;
+	}
+
+	while (index < cache_leaves(cpu)) {
+		this_leaf = per_cpu_cacheinfo_idx(cpu, 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; }
+#endif
+
+int __weak cache_setup_acpi(unsigned int cpu)
+{
+	return -ENOTSUPP;
+}
+
+unsigned int coherency_max_size;
+
+static int cache_setup_properties(unsigned int cpu)
+{
+	int ret = 0;
+
+	if (of_have_populated_dt())
+		ret = cache_setup_of_node(cpu);
+	else if (!acpi_disabled)
+		ret = cache_setup_acpi(cpu);
+
+	return ret;
+}
+
+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, sib_index;
+	int ret = 0;
+
+	if (this_cpu_ci->cpu_map_populated)
+		return 0;
+
+	/*
+	 * skip setting up cache properties if LLC is valid, just need
+	 * to update the shared cpu_map if the cache attributes were
+	 * populated early before all the cpus are brought online
+	 */
+	if (!last_level_cache_is_valid(cpu)) {
+		ret = cache_setup_properties(cpu);
+		if (ret)
+			return ret;
+	}
+
+	for (index = 0; index < cache_leaves(cpu); index++) {
+		unsigned int i;
+
+		this_leaf = per_cpu_cacheinfo_idx(cpu, 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 */
+			for (sib_index = 0; sib_index < cache_leaves(i); sib_index++) {
+				sib_leaf = per_cpu_cacheinfo_idx(i, sib_index);
+
+				/*
+				 * Comparing cache IDs only makes sense if the leaves
+				 * belong to the same cache level of same type. Skip
+				 * the check if level and type do not match.
+				 */
+				if (sib_leaf->level != this_leaf->level ||
+				    sib_leaf->type != this_leaf->type)
+					continue;
+
+				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);
+					break;
+				}
+			}
+		}
+		/* 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 cacheinfo *this_leaf, *sib_leaf;
+	unsigned int sibling, index, sib_index;
+
+	for (index = 0; index < cache_leaves(cpu); index++) {
+		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
+		for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
+			struct cpu_cacheinfo *sib_cpu_ci =
+						get_cpu_cacheinfo(sibling);
+
+			if (sibling == cpu || !sib_cpu_ci->info_list)
+				continue;/* skip if itself or no cacheinfo */
+
+			for (sib_index = 0; sib_index < cache_leaves(sibling); sib_index++) {
+				sib_leaf = per_cpu_cacheinfo_idx(sibling, sib_index);
+
+				/*
+				 * Comparing cache IDs only makes sense if the leaves
+				 * belong to the same cache level of same type. Skip
+				 * the check if level and type do not match.
+				 */
+				if (sib_leaf->level != this_leaf->level ||
+				    sib_leaf->type != this_leaf->type)
+					continue;
+
+				if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
+					cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
+					cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
+					break;
+				}
+			}
+		}
+		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;
+	cache_leaves(cpu) = 0;
+}
+
+int __weak init_cache_level(unsigned int cpu)
+{
+	return -ENOENT;
+}
+
+int __weak populate_cache_leaves(unsigned int cpu)
+{
+	return -ENOENT;
+}
+
+int detect_cache_attributes(unsigned int cpu)
+{
+	int ret;
+
+	/* Since early detection of the cacheinfo is allowed via this
+	 * function and this also gets called as CPU hotplug callbacks via
+	 * cacheinfo_cpu_online, the initialisation can be skipped and only
+	 * CPU maps can be updated as the CPU online status would be update
+	 * if called via cacheinfo_cpu_online path.
+	 */
+	if (per_cpu_cacheinfo(cpu))
+		goto update_cpu_map;
+
+	if (init_cache_level(cpu) || !cache_leaves(cpu))
+		return -ENOENT;
+
+	per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
+					 sizeof(struct cacheinfo), GFP_ATOMIC);
+	if (per_cpu_cacheinfo(cpu) == NULL) {
+		cache_leaves(cpu) = 0;
+		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;
+
+update_cpu_map:
+	/*
+	 * 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 sysfs_emit(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 sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
+}
+
+static ssize_t shared_cpu_map_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
+	const struct cpumask *mask = &this_leaf->shared_cpu_map;
+
+	return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
+}
+
+static ssize_t shared_cpu_list_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
+	const struct cpumask *mask = &this_leaf->shared_cpu_map;
+
+	return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
+}
+
+static ssize_t type_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
+	const char *output;
+
+	switch (this_leaf->type) {
+	case CACHE_TYPE_DATA:
+		output = "Data";
+		break;
+	case CACHE_TYPE_INST:
+		output = "Instruction";
+		break;
+	case CACHE_TYPE_UNIFIED:
+		output = "Unified";
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return sysfs_emit(buf, "%s\n", output);
+}
+
+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;
+	const char *output;
+
+	if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
+		output = "ReadWriteAllocate";
+	else if (ci_attr & CACHE_READ_ALLOCATE)
+		output = "ReadAllocate";
+	else if (ci_attr & CACHE_WRITE_ALLOCATE)
+		output = "WriteAllocate";
+	else
+		return 0;
+
+	return sysfs_emit(buf, "%s\n", output);
+}
+
+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 = sysfs_emit(buf, "WriteThrough\n");
+	else if (ci_attr & CACHE_WRITE_BACK)
+		n = sysfs_emit(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;
+	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 = per_cpu_cacheinfo_idx(cpu, 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);