[PATCH 0/9] drivers: cacheinfo support

[PATCH 0/9] drivers: cacheinfo support

[Sudeep Holla]

From: Sudeep Holla <sudeep.holla@arm.com>

This series adds a generic cacheinfo support similar to topology. The
implementation is based on x86 cacheinfo support. Currently x86, powerpc,
ia64 and s390 have their own implementations. While adding similar support
to ARM and ARM64, here is the attempt to make it generic quite similar to
topology info support. It also adds the missing ABI documentation for
the cacheinfo sysfs which is already being used.

It moves all the existing different implementations on x86, ia64, powerpc
and s390 to use the generic cacheinfo infrastructure introduced here.
These changes on non-ARM platforms are only compile tested and tested on x86.

This series also adds support for ARM and ARM64 architectures based on
the generic support.

Since there was no objection to the idea in RFC, I am posting non-RFC
version here.

The code can be fetched from:
 git://linux-arm.org/linux-skn cacheinfo

Previous RFCs:
[1] https://lkml.org/lkml/2014/1/8/523
[2] https://lkml.org/lkml/2014/2/7/654
[3] https://lkml.org/lkml/2014/2/19/391

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org

---
Sudeep Holla (9):
  drivers: base: add new class "cpu" to group cpu devices
  drivers: base: support cpu cache information interface to userspace
    via sysfs
  ia64: move cacheinfo sysfs to generic cacheinfo infrastructure
  s390: move cacheinfo sysfs to generic cacheinfo infrastructure
  x86: move cacheinfo sysfs to generic cacheinfo infrastructure
  powerpc: move cacheinfo sysfs to generic cacheinfo infrastructure
  ARM64: kernel: add support for cpu cache information
  ARM: kernel: add support for cpu cache information
  ARM: kernel: add outer cache support for cacheinfo implementation

 Documentation/ABI/testing/sysfs-devices-system-cpu |  41 ++
 arch/arm/include/asm/outercache.h                  |  13 +
 arch/arm/kernel/Makefile                           |   1 +
 arch/arm/kernel/cacheinfo.c                        | 249 +++++++
 arch/arm/mm/Kconfig                                |  13 +
 arch/arm/mm/cache-l2x0.c                           |  10 +
 arch/arm/mm/cache-tauros2.c                        |  34 +
 arch/arm/mm/cache-xsc3l2.c                         |  15 +
 arch/arm64/kernel/Makefile                         |   3 +-
 arch/arm64/kernel/cacheinfo.c                      | 135 ++++
 arch/ia64/kernel/topology.c                        | 401 ++--------
 arch/powerpc/kernel/cacheinfo.c                    | 813 +++------------------
 arch/powerpc/kernel/cacheinfo.h                    |   8 -
 arch/powerpc/kernel/sysfs.c                        |  12 +-
 arch/s390/kernel/cache.c                           | 388 +++-------
 arch/x86/kernel/cpu/intel_cacheinfo.c              | 655 ++++-------------
 drivers/base/Makefile                              |   2 +-
 drivers/base/cacheinfo.c                           | 564 ++++++++++++++
 drivers/base/core.c                                |  39 +-
 drivers/base/cpu.c                                 |   7 +
 include/linux/cacheinfo.h                          |  56 ++
 include/linux/cpu.h                                |   2 +
 22 files changed, 1590 insertions(+), 1871 deletions(-)
 create mode 100644 arch/arm/kernel/cacheinfo.c
 create mode 100644 arch/arm64/kernel/cacheinfo.c
 delete mode 100644 arch/powerpc/kernel/cacheinfo.h
 create mode 100644 drivers/base/cacheinfo.c
 create mode 100644 include/linux/cacheinfo.h

-- 
1.8.3.2

[PATCH 2/9] drivers: base: support cpu cache information interface to userspace via sysfs

[Sudeep Holla]

From: Sudeep Holla <sudeep.holla@arm.com>

This patch adds initial support for providing processor cache information
to userspace through sysfs interface. This is based on already existing
implementations(x86, ia64, s390 and powerpc) and hence the interface is
intended to be fully compatible.

The main purpose of this generic support is to avoid further code
duplication to support new architectures and also to unify all the existing
different implementations.

This implementation maintains the hierarchy of cache objects which reflects
the system's cache topology. Cache devices are instantiated as needed as
CPUs come online. The cache information is replicated per-cpu even if they are
shared. A per-cpu array of cache information maintained is used mainly for
sysfs-related book keeping.

It also implements the shared_cpu_map attribute, which is essential for
enabling both kernel and user-space to discover the system's overall cache
topology.

This patch also add the missing ABI documentation for the cacheinfo sysfs
interface already, which is well defined and widely used.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh@kernel.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
---
 Documentation/ABI/testing/sysfs-devices-system-cpu |  41 ++
 drivers/base/Makefile                              |   2 +-
 drivers/base/cacheinfo.c                           | 564 +++++++++++++++++++++
 include/linux/cacheinfo.h                          |  56 ++
 4 files changed, 662 insertions(+), 1 deletion(-)
 create mode 100644 drivers/base/cacheinfo.c
 create mode 100644 include/linux/cacheinfo.h

diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index acb9bfc..5827f4e 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -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
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 04b314e..bad2ff8 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -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/
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
new file mode 100644
index 0000000..c12e03c
--- /dev/null
+++ b/drivers/base/cacheinfo.c
@@ -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 */
diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
new file mode 100644
index 0000000..a9bd9f9
--- /dev/null
+++ b/include/linux/cacheinfo.h
@@ -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 */
-- 
1.8.3.2

[PATCH 6/9] powerpc: move cacheinfo sysfs to generic cacheinfo infrastructure

[Sudeep Holla]

From: Sudeep Holla <sudeep.holla@arm.com>

This patch removes the redundant sysfs cacheinfo code by making use of
the newly introduced generic cacheinfo infrastructure.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/cacheinfo.c | 813 +++++-----------------------------------
 arch/powerpc/kernel/cacheinfo.h |   8 -
 arch/powerpc/kernel/sysfs.c     |  12 +-
 3 files changed, 91 insertions(+), 742 deletions(-)
 delete mode 100644 arch/powerpc/kernel/cacheinfo.h

diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c
index 40198d5..b871c24 100644
--- a/arch/powerpc/kernel/cacheinfo.c
+++ b/arch/powerpc/kernel/cacheinfo.c
@@ -10,38 +10,10 @@
  * 2 as published by the Free Software Foundation.
  */
 
+#include <linux/cacheinfo.h>
 #include <linux/cpu.h>
-#include <linux/cpumask.h>
 #include <linux/kernel.h>
-#include <linux/kobject.h>
-#include <linux/list.h>
-#include <linux/notifier.h>
 #include <linux/of.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <asm/prom.h>
-
-#include "cacheinfo.h"
-
-/* per-cpu object for tracking:
- * - a "cache" kobject for the top-level directory
- * - a list of "index" objects representing the cpu's local cache hierarchy
- */
-struct cache_dir {
-	struct kobject *kobj; /* bare (not embedded) kobject for cache
-			       * directory */
-	struct cache_index_dir *index; /* list of index objects */
-};
-
-/* "index" object: each cpu's cache directory has an index
- * subdirectory corresponding to a cache object associated with the
- * cpu.  This object's lifetime is managed via the embedded kobject.
- */
-struct cache_index_dir {
-	struct kobject kobj;
-	struct cache_index_dir *next; /* next index in parent directory */
-	struct cache *cache;
-};
 
 /* Template for determining which OF properties to query for a given
  * cache type */
@@ -60,11 +32,6 @@ struct cache_type_info {
 	const char *nr_sets_prop;
 };
 
-/* These are used to index the cache_type_info array. */
-#define CACHE_TYPE_UNIFIED     0
-#define CACHE_TYPE_INSTRUCTION 1
-#define CACHE_TYPE_DATA        2
-
 static const struct cache_type_info cache_type_info[] = {
 	{
 		/* PowerPC Processor binding says the [di]-cache-*
@@ -92,231 +59,83 @@ static const struct cache_type_info cache_type_info[] = {
 	},
 };
 
-/* Cache object: each instance of this corresponds to a distinct cache
- * in the system.  There are separate objects for Harvard caches: one
- * each for instruction and data, and each refers to the same OF node.
- * The refcount of the OF node is elevated for the lifetime of the
- * cache object.  A cache object is released when its shared_cpu_map
- * is cleared (see cache_cpu_clear).
- *
- * A cache object is on two lists: an unsorted global list
- * (cache_list) of cache objects; and a singly-linked list
- * representing the local cache hierarchy, which is ordered by level
- * (e.g. L1d -> L1i -> L2 -> L3).
- */
-struct cache {
-	struct device_node *ofnode;    /* OF node for this cache, may be cpu */
-	struct cpumask shared_cpu_map; /* online CPUs using this cache */
-	int type;                      /* split cache disambiguation */
-	int level;                     /* level not explicit in device tree */
-	struct list_head list;         /* global list of cache objects */
-	struct cache *next_local;      /* next cache of >= level */
-};
-
-static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu);
-
-/* traversal/modification of this list occurs only at cpu hotplug time;
- * access is serialized by cpu hotplug locking
- */
-static LIST_HEAD(cache_list);
-
-static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k)
-{
-	return container_of(k, struct cache_index_dir, kobj);
-}
-
-static const char *cache_type_string(const struct cache *cache)
+static inline int get_cacheinfo_idx(enum cache_type type)
 {
-	return cache_type_info[cache->type].name;
-}
-
-static void cache_init(struct cache *cache, int type, int level,
-		       struct device_node *ofnode)
-{
-	cache->type = type;
-	cache->level = level;
-	cache->ofnode = of_node_get(ofnode);
-	INIT_LIST_HEAD(&cache->list);
-	list_add(&cache->list, &cache_list);
-}
-
-static struct cache *new_cache(int type, int level, struct device_node *ofnode)
-{
-	struct cache *cache;
-
-	cache = kzalloc(sizeof(*cache), GFP_KERNEL);
-	if (cache)
-		cache_init(cache, type, level, ofnode);
-
-	return cache;
-}
-
-static void release_cache_debugcheck(struct cache *cache)
-{
-	struct cache *iter;
-
-	list_for_each_entry(iter, &cache_list, list)
-		WARN_ONCE(iter->next_local == cache,
-			  "cache for %s(%s) refers to cache for %s(%s)\n",
-			  iter->ofnode->full_name,
-			  cache_type_string(iter),
-			  cache->ofnode->full_name,
-			  cache_type_string(cache));
-}
-
-static void release_cache(struct cache *cache)
-{
-	if (!cache)
-		return;
-
-	pr_debug("freeing L%d %s cache for %s\n", cache->level,
-		 cache_type_string(cache), cache->ofnode->full_name);
-
-	release_cache_debugcheck(cache);
-	list_del(&cache->list);
-	of_node_put(cache->ofnode);
-	kfree(cache);
-}
-
-static void cache_cpu_set(struct cache *cache, int cpu)
-{
-	struct cache *next = cache;
-
-	while (next) {
-		WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
-			  "CPU %i already accounted in %s(%s)\n",
-			  cpu, next->ofnode->full_name,
-			  cache_type_string(next));
-		cpumask_set_cpu(cpu, &next->shared_cpu_map);
-		next = next->next_local;
-	}
+	if (type == CACHE_TYPE_UNIFIED)
+		return 0;
+	else
+		return type;
 }
 
-static int cache_size(const struct cache *cache, unsigned int *ret)
+static void cache_size(struct cacheinfo *this_leaf)
 {
 	const char *propname;
 	const __be32 *cache_size;
+	int ct_idx;
 
-	propname = cache_type_info[cache->type].size_prop;
+	ct_idx = get_cacheinfo_idx(this_leaf->type);
+	propname = cache_type_info[ct_idx].size_prop;
 
-	cache_size = of_get_property(cache->ofnode, propname, NULL);
+	cache_size = of_get_property(this_leaf->of_node, propname, NULL);
 	if (!cache_size)
-		return -ENODEV;
-
-	*ret = of_read_number(cache_size, 1);
-	return 0;
-}
-
-static int cache_size_kb(const struct cache *cache, unsigned int *ret)
-{
-	unsigned int size;
-
-	if (cache_size(cache, &size))
-		return -ENODEV;
-
-	*ret = size / 1024;
-	return 0;
+		this_leaf->size = 0;
+	else
+		this_leaf->size = of_read_number(cache_size, 1);
 }
 
 /* not cache_line_size() because that's a macro in include/linux/cache.h */
-static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
+static void cache_get_line_size(struct cacheinfo *this_leaf)
 {
 	const __be32 *line_size;
-	int i, lim;
+	int i, lim, ct_idx;
 
-	lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
+	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++) {
 		const char *propname;
 
-		propname = cache_type_info[cache->type].line_size_props[i];
-		line_size = of_get_property(cache->ofnode, propname, NULL);
+		propname = cache_type_info[ct_idx].line_size_props[i];
+		line_size = of_get_property(this_leaf->of_node, propname, NULL);
 		if (line_size)
 			break;
 	}
 
 	if (!line_size)
-		return -ENODEV;
-
-	*ret = of_read_number(line_size, 1);
-	return 0;
+		this_leaf->coherency_line_size = 0;
+	else
+		this_leaf->coherency_line_size = of_read_number(line_size, 1);
 }
 
-static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
+static void cache_nr_sets(struct cacheinfo *this_leaf)
 {
 	const char *propname;
 	const __be32 *nr_sets;
+	int ct_idx;
 
-	propname = cache_type_info[cache->type].nr_sets_prop;
+	ct_idx = get_cacheinfo_idx(this_leaf->type);
+	propname = cache_type_info[ct_idx].nr_sets_prop;
 
-	nr_sets = of_get_property(cache->ofnode, propname, NULL);
+	nr_sets = of_get_property(this_leaf->of_node, propname, NULL);
 	if (!nr_sets)
-		return -ENODEV;
-
-	*ret = of_read_number(nr_sets, 1);
-	return 0;
+		this_leaf->number_of_sets = 0;
+	else
+		this_leaf->number_of_sets = of_read_number(nr_sets, 1);
 }
 
-static int cache_associativity(const struct cache *cache, unsigned int *ret)
+static void cache_associativity(struct cacheinfo *this_leaf)
 {
-	unsigned int line_size;
-	unsigned int nr_sets;
-	unsigned int size;
-
-	if (cache_nr_sets(cache, &nr_sets))
-		goto err;
+	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) {
-		*ret = 0;
-		return 0;
-	}
-
-	if (cache_get_line_size(cache, &line_size))
-		goto err;
-	if (cache_size(cache, &size))
-		goto err;
-
-	if (!(nr_sets > 0 && size > 0 && line_size > 0))
-		goto err;
-
-	*ret = (size / nr_sets) / line_size;
-	return 0;
-err:
-	return -ENODEV;
-}
-
-/* helper for dealing with split caches */
-static struct cache *cache_find_first_sibling(struct cache *cache)
-{
-	struct cache *iter;
-
-	if (cache->type == CACHE_TYPE_UNIFIED)
-		return cache;
-
-	list_for_each_entry(iter, &cache_list, list)
-		if (iter->ofnode == cache->ofnode && iter->next_local == cache)
-			return iter;
-
-	return cache;
-}
-
-/* return the first cache on a local list matching node */
-static struct cache *cache_lookup_by_node(const struct device_node *node)
-{
-	struct cache *cache = NULL;
-	struct cache *iter;
-
-	list_for_each_entry(iter, &cache_list, list) {
-		if (iter->ofnode != node)
-			continue;
-		cache = cache_find_first_sibling(iter);
-		break;
-	}
-
-	return cache;
+	if ((nr_sets == 1) || !(nr_sets > 0 && size > 0 && line_size > 0))
+		this_leaf->ways_of_associativity = 0;
+	else
+		this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 }
 
 static bool cache_node_is_unified(const struct device_node *np)
@@ -324,526 +143,74 @@ static bool cache_node_is_unified(const struct device_node *np)
 	return of_get_property(np, "cache-unified", NULL);
 }
 
-static struct cache *cache_do_one_devnode_unified(struct device_node *node,
-						  int level)
-{
-	struct cache *cache;
-
-	pr_debug("creating L%d ucache for %s\n", level, node->full_name);
-
-	cache = new_cache(CACHE_TYPE_UNIFIED, level, node);
-
-	return cache;
-}
-
-static struct cache *cache_do_one_devnode_split(struct device_node *node,
-						int level)
-{
-	struct cache *dcache, *icache;
-
-	pr_debug("creating L%d dcache and icache for %s\n", level,
-		 node->full_name);
-
-	dcache = new_cache(CACHE_TYPE_DATA, level, node);
-	icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
-
-	if (!dcache || !icache)
-		goto err;
-
-	dcache->next_local = icache;
-
-	return dcache;
-err:
-	release_cache(dcache);
-	release_cache(icache);
-	return NULL;
-}
-
-static struct cache *cache_do_one_devnode(struct device_node *node, int level)
-{
-	struct cache *cache;
-
-	if (cache_node_is_unified(node))
-		cache = cache_do_one_devnode_unified(node, level);
-	else
-		cache = cache_do_one_devnode_split(node, level);
-
-	return cache;
-}
-
-static struct cache *cache_lookup_or_instantiate(struct device_node *node,
-						 int level)
-{
-	struct cache *cache;
-
-	cache = cache_lookup_by_node(node);
-
-	WARN_ONCE(cache && cache->level != level,
-		  "cache level mismatch on lookup (got %d, expected %d)\n",
-		  cache->level, level);
-
-	if (!cache)
-		cache = cache_do_one_devnode(node, level);
-
-	return cache;
-}
-
-static void link_cache_lists(struct cache *smaller, struct cache *bigger)
-{
-	while (smaller->next_local) {
-		if (smaller->next_local == bigger)
-			return; /* already linked */
-		smaller = smaller->next_local;
-	}
-
-	smaller->next_local = bigger;
-}
-
-static void do_subsidiary_caches_debugcheck(struct cache *cache)
-{
-	WARN_ON_ONCE(cache->level != 1);
-	WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu"));
-}
-
-static void do_subsidiary_caches(struct cache *cache)
-{
-	struct device_node *subcache_node;
-	int level = cache->level;
-
-	do_subsidiary_caches_debugcheck(cache);
-
-	while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
-		struct cache *subcache;
-
-		level++;
-		subcache = cache_lookup_or_instantiate(subcache_node, level);
-		of_node_put(subcache_node);
-		if (!subcache)
-			break;
-
-		link_cache_lists(cache, subcache);
-		cache = subcache;
-	}
-}
-
-static struct cache *cache_chain_instantiate(unsigned int cpu_id)
-{
-	struct device_node *cpu_node;
-	struct cache *cpu_cache = NULL;
-
-	pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
-
-	cpu_node = of_get_cpu_node(cpu_id, NULL);
-	WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
-	if (!cpu_node)
-		goto out;
-
-	cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
-	if (!cpu_cache)
-		goto out;
-
-	do_subsidiary_caches(cpu_cache);
-
-	cache_cpu_set(cpu_cache, cpu_id);
-out:
-	of_node_put(cpu_node);
-
-	return cpu_cache;
-}
-
-static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id)
-{
-	struct cache_dir *cache_dir;
-	struct device *dev;
-	struct kobject *kobj = NULL;
-
-	dev = get_cpu_device(cpu_id);
-	WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id);
-	if (!dev)
-		goto err;
-
-	kobj = kobject_create_and_add("cache", &dev->kobj);
-	if (!kobj)
-		goto err;
-
-	cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
-	if (!cache_dir)
-		goto err;
-
-	cache_dir->kobj = kobj;
-
-	WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
-
-	per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
-
-	return cache_dir;
-err:
-	kobject_put(kobj);
-	return NULL;
-}
-
-static void cache_index_release(struct kobject *kobj)
-{
-	struct cache_index_dir *index;
-
-	index = kobj_to_cache_index_dir(kobj);
-
-	pr_debug("freeing index directory for L%d %s cache\n",
-		 index->cache->level, cache_type_string(index->cache));
-
-	kfree(index);
-}
-
-static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
+static void ci_leaf_init(struct cacheinfo *this_leaf,
+			 enum cache_type type, unsigned int level)
 {
-	struct kobj_attribute *kobj_attr;
-
-	kobj_attr = container_of(attr, struct kobj_attribute, attr);
-
-	return kobj_attr->show(k, kobj_attr, buf);
+	this_leaf->level = level;
+	this_leaf->type = type;
+	cache_size(this_leaf);
+	cache_get_line_size(this_leaf);
+	cache_nr_sets(this_leaf);
+	cache_associativity(this_leaf);
 }
 
-static struct cache *index_kobj_to_cache(struct kobject *k)
+int init_cache_level(unsigned int cpu)
 {
-	struct cache_index_dir *index;
+	struct device_node *np;
+	struct device *cpu_dev = get_cpu_device(cpu);
+	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+	unsigned int level = 0, leaves = 0;
 
-	index = kobj_to_cache_index_dir(k);
-
-	return index->cache;
-}
-
-static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int size_kb;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_size_kb(cache, &size_kb))
+	if (!cpu_dev) {
+		pr_err("No cpu device for CPU %d\n", cpu);
 		return -ENODEV;
-
-	return sprintf(buf, "%uK\n", size_kb);
-}
-
-static struct kobj_attribute cache_size_attr =
-	__ATTR(size, 0444, size_show, NULL);
-
-
-static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int line_size;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_get_line_size(cache, &line_size))
-		return -ENODEV;
-
-	return sprintf(buf, "%u\n", line_size);
-}
-
-static struct kobj_attribute cache_line_size_attr =
-	__ATTR(coherency_line_size, 0444, line_size_show, NULL);
-
-static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int nr_sets;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_nr_sets(cache, &nr_sets))
-		return -ENODEV;
-
-	return sprintf(buf, "%u\n", nr_sets);
-}
-
-static struct kobj_attribute cache_nr_sets_attr =
-	__ATTR(number_of_sets, 0444, nr_sets_show, NULL);
-
-static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int associativity;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_associativity(cache, &associativity))
-		return -ENODEV;
-
-	return sprintf(buf, "%u\n", associativity);
-}
-
-static struct kobj_attribute cache_assoc_attr =
-	__ATTR(ways_of_associativity, 0444, associativity_show, NULL);
-
-static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	return sprintf(buf, "%s\n", cache_type_string(cache));
-}
-
-static struct kobj_attribute cache_type_attr =
-	__ATTR(type, 0444, type_show, NULL);
-
-static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache_index_dir *index;
-	struct cache *cache;
-
-	index = kobj_to_cache_index_dir(k);
-	cache = index->cache;
-
-	return sprintf(buf, "%d\n", cache->level);
-}
-
-static struct kobj_attribute cache_level_attr =
-	__ATTR(level, 0444, level_show, NULL);
-
-static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache_index_dir *index;
-	struct cache *cache;
-	int len;
-	int n = 0;
-
-	index = kobj_to_cache_index_dir(k);
-	cache = index->cache;
-	len = PAGE_SIZE - 2;
-
-	if (len > 1) {
-		n = cpumask_scnprintf(buf, len, &cache->shared_cpu_map);
-		buf[n++] = '\n';
-		buf[n] = '\0';
 	}
-	return n;
-}
-
-static struct kobj_attribute cache_shared_cpu_map_attr =
-	__ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
-
-/* Attributes which should always be created -- the kobject/sysfs core
- * does this automatically via kobj_type->default_attrs.  This is the
- * minimum data required to uniquely identify a cache.
- */
-static struct attribute *cache_index_default_attrs[] = {
-	&cache_type_attr.attr,
-	&cache_level_attr.attr,
-	&cache_shared_cpu_map_attr.attr,
-	NULL,
-};
-
-/* Attributes which should be created if the cache device node has the
- * right properties -- see cacheinfo_create_index_opt_attrs
- */
-static struct kobj_attribute *cache_index_opt_attrs[] = {
-	&cache_size_attr,
-	&cache_line_size_attr,
-	&cache_nr_sets_attr,
-	&cache_assoc_attr,
-};
-
-static const struct sysfs_ops cache_index_ops = {
-	.show = cache_index_show,
-};
-
-static struct kobj_type cache_index_type = {
-	.release = cache_index_release,
-	.sysfs_ops = &cache_index_ops,
-	.default_attrs = cache_index_default_attrs,
-};
-
-static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
-{
-	const char *cache_name;
-	const char *cache_type;
-	struct cache *cache;
-	char *buf;
-	int i;
-
-	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!buf)
-		return;
-
-	cache = dir->cache;
-	cache_name = cache->ofnode->full_name;
-	cache_type = cache_type_string(cache);
-
-	/* We don't want to create an attribute that can't provide a
-	 * meaningful value.  Check the return value of each optional
-	 * attribute's ->show method before registering the
-	 * attribute.
-	 */
-	for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
-		struct kobj_attribute *attr;
-		ssize_t rc;
-
-		attr = cache_index_opt_attrs[i];
-
-		rc = attr->show(&dir->kobj, attr, buf);
-		if (rc <= 0) {
-			pr_debug("not creating %s attribute for "
-				 "%s(%s) (rc = %zd)\n",
-				 attr->attr.name, cache_name,
-				 cache_type, rc);
-			continue;
-		}
-		if (sysfs_create_file(&dir->kobj, &attr->attr))
-			pr_debug("could not create %s attribute for %s(%s)\n",
-				 attr->attr.name, cache_name, cache_type);
+	np = cpu_dev->of_node;
+	if (!np) {
+		pr_err("Failed to find cpu%d device node\n", cpu);
+		return -ENOENT;
 	}
 
-	kfree(buf);
-}
-
-static void cacheinfo_create_index_dir(struct cache *cache, int index,
-				       struct cache_dir *cache_dir)
-{
-	struct cache_index_dir *index_dir;
-	int rc;
-
-	index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
-	if (!index_dir)
-		goto err;
-
-	index_dir->cache = cache;
-
-	rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
-				  cache_dir->kobj, "index%d", index);
-	if (rc)
-		goto err;
-
-	index_dir->next = cache_dir->index;
-	cache_dir->index = index_dir;
-
-	cacheinfo_create_index_opt_attrs(index_dir);
-
-	return;
-err:
-	kfree(index_dir);
-}
-
-static void cacheinfo_sysfs_populate(unsigned int cpu_id,
-				     struct cache *cache_list)
-{
-	struct cache_dir *cache_dir;
-	struct cache *cache;
-	int index = 0;
-
-	cache_dir = cacheinfo_create_cache_dir(cpu_id);
-	if (!cache_dir)
-		return;
-
-	cache = cache_list;
-	while (cache) {
-		cacheinfo_create_index_dir(cache, index, cache_dir);
-		index++;
-		cache = cache->next_local;
+	while (np) {
+		leaves += cache_node_is_unified(np) ? 1 : 2;
+		level++;
+		of_node_put(np);
+		np = of_find_next_cache_node(np);
 	}
-}
+	this_cpu_ci->num_levels = level;
+	this_cpu_ci->num_leaves = leaves;
 
-void cacheinfo_cpu_online(unsigned int cpu_id)
-{
-	struct cache *cache;
-
-	cache = cache_chain_instantiate(cpu_id);
-	if (!cache)
-		return;
-
-	cacheinfo_sysfs_populate(cpu_id, cache);
-}
-
-/* functions needed to remove cache entry for cpu offline or suspend/resume */
-
-#if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \
-    defined(CONFIG_HOTPLUG_CPU)
-
-static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
-{
-	struct device_node *cpu_node;
-	struct cache *cache;
-
-	cpu_node = of_get_cpu_node(cpu_id, NULL);
-	WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
-	if (!cpu_node)
-		return NULL;
-
-	cache = cache_lookup_by_node(cpu_node);
-	of_node_put(cpu_node);
-
-	return cache;
+	return 0;
 }
 
-static void remove_index_dirs(struct cache_dir *cache_dir)
+int populate_cache_leaves(unsigned int cpu)
 {
-	struct cache_index_dir *index;
-
-	index = cache_dir->index;
+	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
+	struct device *cpu_dev = get_cpu_device(cpu);
+	struct device_node *np;
+	unsigned int level, idx;
 
-	while (index) {
-		struct cache_index_dir *next;
-
-		next = index->next;
-		kobject_put(&index->kobj);
-		index = next;
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		pr_err("Failed to find cpu%d device node\n", cpu);
+		return -ENOENT;
 	}
-}
-
-static void remove_cache_dir(struct cache_dir *cache_dir)
-{
-	remove_index_dirs(cache_dir);
 
-	/* Remove cache dir from sysfs */
-	kobject_del(cache_dir->kobj);
-
-	kobject_put(cache_dir->kobj);
-
-	kfree(cache_dir);
-}
-
-static void cache_cpu_clear(struct cache *cache, int cpu)
-{
-	while (cache) {
-		struct cache *next = cache->next_local;
-
-		WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map),
-			  "CPU %i not accounted in %s(%s)\n",
-			  cpu, cache->ofnode->full_name,
-			  cache_type_string(cache));
-
-		cpumask_clear_cpu(cpu, &cache->shared_cpu_map);
-
-		/* Release the cache object if all the cpus using it
-		 * are offline */
-		if (cpumask_empty(&cache->shared_cpu_map))
-			release_cache(cache);
-
-		cache = next;
+	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
+	     idx < this_cpu_ci->num_leaves; idx++, level++) {
+		if (!this_leaf)
+			return -EINVAL;
+
+		this_leaf->of_node = np;
+		if (cache_node_is_unified(np)) {
+			ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
+		} else {
+			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
+			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
+		}
+		np = of_find_next_cache_node(np);
 	}
+	return 0;
 }
 
-void cacheinfo_cpu_offline(unsigned int cpu_id)
-{
-	struct cache_dir *cache_dir;
-	struct cache *cache;
-
-	/* Prevent userspace from seeing inconsistent state - remove
-	 * the sysfs hierarchy first */
-	cache_dir = per_cpu(cache_dir_pcpu, cpu_id);
-
-	/* careful, sysfs population may have failed */
-	if (cache_dir)
-		remove_cache_dir(cache_dir);
-
-	per_cpu(cache_dir_pcpu, cpu_id) = NULL;
-
-	/* clear the CPU's bit in its cache chain, possibly freeing
-	 * cache objects */
-	cache = cache_lookup_by_cpu(cpu_id);
-	if (cache)
-		cache_cpu_clear(cache, cpu_id);
-}
-#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */
diff --git a/arch/powerpc/kernel/cacheinfo.h b/arch/powerpc/kernel/cacheinfo.h
deleted file mode 100644
index a7b74d3..0000000
--- a/arch/powerpc/kernel/cacheinfo.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef _PPC_CACHEINFO_H
-#define _PPC_CACHEINFO_H
-
-/* These are just hooks for sysfs.c to use. */
-extern void cacheinfo_cpu_online(unsigned int cpu_id);
-extern void cacheinfo_cpu_offline(unsigned int cpu_id);
-
-#endif /* _PPC_CACHEINFO_H */
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 67fd2fd..6e9c5a8 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -19,8 +19,6 @@
 #include <asm/pmc.h>
 #include <asm/firmware.h>
 
-#include "cacheinfo.h"
-
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>
 #include <asm/lppaca.h>
@@ -743,7 +741,6 @@ static void register_cpu_online(unsigned int cpu)
 		device_create_file(s, &dev_attr_altivec_idle_wait_time);
 	}
 #endif
-	cacheinfo_cpu_online(cpu);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -824,7 +821,6 @@ static void unregister_cpu_online(unsigned int cpu)
 		device_remove_file(s, &dev_attr_altivec_idle_wait_time);
 	}
 #endif
-	cacheinfo_cpu_offline(cpu);
 }
 
 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
@@ -988,8 +984,7 @@ static int __init topology_init(void)
 	int cpu;
 
 	register_nodes();
-
-	cpu_notifier_register_begin();
+	register_cpu_notifier(&sysfs_cpu_nb);
 
 	for_each_possible_cpu(cpu) {
 		struct cpu *c = &per_cpu(cpu_devices, cpu);
@@ -1013,11 +1008,6 @@ static int __init topology_init(void)
 		if (cpu_online(cpu))
 			register_cpu_online(cpu);
 	}
-
-	__register_cpu_notifier(&sysfs_cpu_nb);
-
-	cpu_notifier_register_done();
-
 #ifdef CONFIG_PPC64
 	sysfs_create_dscr_default();
 #endif /* CONFIG_PPC64 */
-- 
1.8.3.2

Re: [PATCH 2/9] drivers: base: support cpu cache information interface to userspace via sysfs

[Russell King - ARM Linux]

On Wed, Jun 25, 2014 at 06:30:37PM +0100, Sudeep Holla wrote:
> +		coherency_line_size: the minimum amount of data that gets transferred

So, what value to do envision this taking for a CPU where the cache
line size is 32 bytes, but each cache line has two dirty bits which
allow it to only evict either the upper or lower 16 bytes depending
on which are dirty?

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

Re: [PATCH 2/9] drivers: base: support cpu cache information interface to userspace via sysfs

[Sudeep Holla]

Hi,

On 25/06/14 23:23, Russell King - ARM Linux wrote:
> On Wed, Jun 25, 2014 at 06:30:37PM +0100, Sudeep Holla wrote:
>> +=09=09coherency_line_size: the minimum amount of data that gets transfe=
rred
>
> So, what value to do envision this taking for a CPU where the cache
> line size is 32 bytes, but each cache line has two dirty bits which
> allow it to only evict either the upper or lower 16 bytes depending
> on which are dirty?
>

IIUC most of existing implementations of cacheinfo on various architectures
are representing the cache line size as coherency_line_size, in which case =
I
need fix the definition in this file.

BTW will there be any architectural way of finding such configuration ?

Regards,
Sudeep

Re: [PATCH 2/9] drivers: base: support cpu cache information interface to userspace via sysfs

[Russell King - ARM Linux]

On Thu, Jun 26, 2014 at 07:41:32PM +0100, Sudeep Holla wrote:
> Hi,
>
> On 25/06/14 23:23, Russell King - ARM Linux wrote:
>> On Wed, Jun 25, 2014 at 06:30:37PM +0100, Sudeep Holla wrote:
>>> +		coherency_line_size: the minimum amount of data that gets transferred
>>
>> So, what value to do envision this taking for a CPU where the cache
>> line size is 32 bytes, but each cache line has two dirty bits which
>> allow it to only evict either the upper or lower 16 bytes depending
>> on which are dirty?
>>
>
> IIUC most of existing implementations of cacheinfo on various architectures
> are representing the cache line size as coherency_line_size, in which case I
> need fix the definition in this file.

As an example, here's an extract from the SA110 TRM:

StrongARM contains a 16KByte writeback data cache. The DC has 512 lines
of 32 bytes (8 words), arranged as a 32 way set associative cache, and
uses the virtual addresses generated by the processor. A line also
contains the physical address the block was fetched from and two dirty
bits. There is a dirty bit associated with both the first and second
half of the block. When a store hits in the cache the dirty bit
associated with it is set. When a block is evicted from the cache the
dirty bits are used to decide if all, half, or none of the block will
be written back to memory using the physical address stored with the
block. The DC is always reloaded a line at a time (8 words).

> BTW will there be any architectural way of finding such configuration ?

Not that I know of.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

Re: [PATCH 2/9] drivers: base: support cpu cache information interface to userspace via sysfs

[Sudeep Holla]

On 26/06/14 19:50, Russell King - ARM Linux wrote:
> On Thu, Jun 26, 2014 at 07:41:32PM +0100, Sudeep Holla wrote:
>> Hi,
>>
>> On 25/06/14 23:23, Russell King - ARM Linux wrote:
>>> On Wed, Jun 25, 2014 at 06:30:37PM +0100, Sudeep Holla wrote:
>>>> +=09=09coherency_line_size: the minimum amount of data that gets trans=
ferred
>>>
>>> So, what value to do envision this taking for a CPU where the cache
>>> line size is 32 bytes, but each cache line has two dirty bits which
>>> allow it to only evict either the upper or lower 16 bytes depending
>>> on which are dirty?
>>>
>>
>> IIUC most of existing implementations of cacheinfo on various architectu=
res
>> are representing the cache line size as coherency_line_size, in which ca=
se I
>> need fix the definition in this file.
>
> As an example, here's an extract from the SA110 TRM:
>
> StrongARM contains a 16KByte writeback data cache. The DC has 512 lines
> of 32 bytes (8 words), arranged as a 32 way set associative cache, and
> uses the virtual addresses generated by the processor. A line also
> contains the physical address the block was fetched from and two dirty
> bits. There is a dirty bit associated with both the first and second
> half of the block. When a store hits in the cache the dirty bit
> associated with it is set. When a block is evicted from the cache the
> dirty bits are used to decide if all, half, or none of the block will
> be written back to memory using the physical address stored with the
> block. The DC is always reloaded a line at a time (8 words).
>

Thanks for the information. It's interesting that line is referred as block
when referring to 2 dirty bits. I am not sure if this can be mapped to=20
physical_line_partition =3D 2. Thoughts ?

>> BTW will there be any architectural way of finding such configuration ?
>
> Not that I know of.
>
That's bad :)

Regards,
Sudeep

Re: [PATCH 2/9] drivers: base: support cpu cache information interface to userspace via sysfs

[Greg Kroah-Hartman]

On Wed, Jun 25, 2014 at 06:30:37PM +0100, Sudeep Holla wrote:
> +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;
> +}

Ick, why create your own function for this when the driver core has this
functionality built into it?  Look at the is_visible() callback, and how
it is use for an attribute group please.

> +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]);
> +}

You should just remove a whole group at once, not individually.

> +
> +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;

You just raced with userspace here, creating these files _after_ the
device was announced to userspace, causing problems with anyone wanting
to read these attributes :(

I think if you fix up the is_visible() thing above, these calls will go
away, right?

Re: [PATCH 2/9] drivers: base: support cpu cache information interface to userspace via sysfs

[Sudeep Holla]

Hi Greg,

Thanks for reviewing this.

On 10/07/14 01:09, Greg Kroah-Hartman wrote:
> On Wed, Jun 25, 2014 at 06:30:37PM +0100, Sudeep Holla wrote:
>> +static const struct device_attribute *cache_optional_attrs[] =3D {
>> +=09&dev_attr_coherency_line_size,
>> +=09&dev_attr_ways_of_associativity,
>> +=09&dev_attr_number_of_sets,
>> +=09&dev_attr_size,
>> +=09&dev_attr_attributes,
>> +=09&dev_attr_physical_line_partition,
>> +=09NULL
>> +};
>> +
>> +static int device_add_attrs(struct device *dev,
>> +=09=09=09    const struct device_attribute **dev_attrs)
>> +{
>> +=09int i, error =3D 0;
>> +=09struct device_attribute *dev_attr;
>> +=09char *buf;
>> +
>> +=09if (!dev_attrs)
>> +=09=09return 0;
>> +
>> +=09buf =3D kmalloc(PAGE_SIZE, GFP_KERNEL);
>> +=09if (!buf)
>> +=09=09return -ENOMEM;
>> +
>> +=09for (i =3D 0; dev_attrs[i]; i++) {
>> +=09=09dev_attr =3D (struct device_attribute *)dev_attrs[i];
>> +
>> +=09=09/* create attributes that provides meaningful value */
>> +=09=09if (dev_attr->show(dev, dev_attr, buf) < 0)
>> +=09=09=09continue;
>> +
>> +=09=09error =3D device_create_file(dev, dev_attrs[i]);
>> +=09=09if (error) {
>> +=09=09=09while (--i >=3D 0)
>> +=09=09=09=09device_remove_file(dev, dev_attrs[i]);
>> +=09=09=09break;
>> +=09=09}
>> +=09}
>> +
>> +=09kfree(buf);
>> +=09return error;
>> +}
>
> Ick, why create your own function for this when the driver core has this
> functionality built into it?  Look at the is_visible() callback, and how
> it is use for an attribute group please.
>

I agree even I added this function hesitantly as didn't realize that I can =
use
is_visible for this purpose. Thanks for pointing that out I will have a loo=
k
at it.

>> +static void device_remove_attrs(struct device *dev,
>> +=09=09=09=09const struct device_attribute **dev_attrs)
>> +{
>> +=09int i;
>> +
>> +=09if (!dev_attrs)
>> +=09=09return;
>> +
>> +=09for (i =3D 0; dev_attrs[i]; dev_attrs++, i++)
>> +=09=09device_remove_file(dev, dev_attrs[i]);
>> +}
>
> You should just remove a whole group at once, not individually.
>

Right, I must be able to get rid of these 2 functions once I use
is_visible callback.

>> +
>> +const struct device_attribute **
>> +__weak cache_get_priv_attr(struct device *cache_idx_dev)
>> +{
>> +=09return NULL;
>> +}
>> +
>> +/* Add/Remove cache interface for CPU device */
>> +static void cpu_cache_sysfs_exit(unsigned int cpu)
>> +{
>> +=09int i;
>> +=09struct device *tmp_dev;
>> +=09const struct device_attribute **ci_priv_attr;
>> +
>> +=09if (per_cpu_index_dev(cpu)) {
>> +=09=09for (i =3D 0; i < cache_leaves(cpu); i++) {
>> +=09=09=09tmp_dev =3D per_cache_index_dev(cpu, i);
>> +=09=09=09if (!tmp_dev)
>> +=09=09=09=09continue;
>> +=09=09=09ci_priv_attr =3D cache_get_priv_attr(tmp_dev);
>> +=09=09=09device_remove_attrs(tmp_dev, ci_priv_attr);
>> +=09=09=09device_remove_attrs(tmp_dev, cache_optional_attrs);
>> +=09=09=09device_unregister(tmp_dev);
>> +=09=09}
>> +=09=09kfree(per_cpu_index_dev(cpu));
>> +=09=09per_cpu_index_dev(cpu) =3D NULL;
>> +=09}
>> +=09device_unregister(per_cpu_cache_dev(cpu));
>> +=09per_cpu_cache_dev(cpu) =3D NULL;
>> +}
>> +
>> +static int cpu_cache_sysfs_init(unsigned int cpu)
>> +{
>> +=09struct device *dev =3D get_cpu_device(cpu);
>> +
>> +=09if (per_cpu_cacheinfo(cpu) =3D=3D NULL)
>> +=09=09return -ENOENT;
>> +
>> +=09per_cpu_cache_dev(cpu) =3D device_create(dev->class, dev, cpu,
>> +=09=09=09=09=09       NULL, "cache");
>> +=09if (IS_ERR_OR_NULL(per_cpu_cache_dev(cpu)))
>> +=09=09return PTR_ERR(per_cpu_cache_dev(cpu));
>> +
>> +=09/* Allocate all required memory */
>> +=09per_cpu_index_dev(cpu) =3D kzalloc(sizeof(struct device *) *
>> +=09=09=09=09=09 cache_leaves(cpu), GFP_KERNEL);
>> +=09if (unlikely(per_cpu_index_dev(cpu) =3D=3D NULL))
>> +=09=09goto err_out;
>> +
>> +=09return 0;
>> +
>> +err_out:
>> +=09cpu_cache_sysfs_exit(cpu);
>> +=09return -ENOMEM;
>> +}
>> +
>> +static int cache_add_dev(unsigned int cpu)
>> +{
>> +=09unsigned short i;
>> +=09int rc;
>> +=09struct device *tmp_dev, *parent;
>> +=09struct cacheinfo *this_leaf;
>> +=09const struct device_attribute **ci_priv_attr;
>> +=09struct cpu_cacheinfo *this_cpu_ci =3D get_cpu_cacheinfo(cpu);
>> +
>> +=09rc =3D cpu_cache_sysfs_init(cpu);
>> +=09if (unlikely(rc < 0))
>> +=09=09return rc;
>> +
>> +=09parent =3D per_cpu_cache_dev(cpu);
>> +=09for (i =3D 0; i < cache_leaves(cpu); i++) {
>> +=09=09this_leaf =3D this_cpu_ci->info_list + i;
>> +=09=09if (this_leaf->disable_sysfs)
>> +=09=09=09continue;
>> +=09=09tmp_dev =3D device_create_with_groups(parent->class, parent, i,
>> +=09=09=09=09=09=09    this_leaf,
>> +=09=09=09=09=09=09    cache_default_groups,
>> +=09=09=09=09=09=09    "index%1u", i);
>> +=09=09if (IS_ERR_OR_NULL(tmp_dev)) {
>> +=09=09=09rc =3D PTR_ERR(tmp_dev);
>> +=09=09=09goto err;
>> +=09=09}
>> +
>> +=09=09rc =3D device_add_attrs(tmp_dev, cache_optional_attrs);
>> +=09=09if (unlikely(rc))
>> +=09=09=09goto err;
>> +
>> +=09=09ci_priv_attr =3D cache_get_priv_attr(tmp_dev);
>> +=09=09rc =3D device_add_attrs(tmp_dev, ci_priv_attr);
>> +=09=09if (unlikely(rc))
>> +=09=09=09goto err;
>
> You just raced with userspace here, creating these files _after_ the
> device was announced to userspace, causing problems with anyone wanting
> to read these attributes :(
>
> I think if you fix up the is_visible() thing above, these calls will go
> away, right?
>

Yes I agree.

Regards,
Sudeep

[PATCH v2 0/9] drivers: cacheinfo support

[Sudeep Holla]

From: Sudeep Holla <sudeep.holla@arm.com>

This series adds a generic cacheinfo support similar to topology. The
implementation is based on x86 cacheinfo support. Currently x86, powerpc,
ia64 and s390 have their own implementations. While adding similar support
to ARM and ARM64, here is the attempt to make it generic quite similar to
topology info support. It also adds the missing ABI documentation for
the cacheinfo sysfs which is already being used.

It moves all the existing different implementations on x86, ia64, powerpc
and s390 to use the generic cacheinfo infrastructure introduced here.
These changes on non-ARM platforms are only compile tested and tested on x86.

This series also adds support for ARM and ARM64 architectures based on
the generic support.

Since there was no objection to the idea in RFC, I am posting non-RFC
version here.

The code can be fetched from:
 git://linux-arm.org/linux-skn cacheinfo


Changes v1->v2:
- removed custom device_{add,remove}_attrs, using is_visible callback
  instead(suggested by GregKH)
- arm64: changes as per MarkR review comments
- Moved smp_call_function_single to architectures using it(arm, arm64,
  x86) (suggested by Stephen Boyd)
- arm (mostly changes as per RMK's review comments)
	- fixed to allow v7 + v6 build
	- l2 cache changes to remove extra structure
	- populated CTR for few StrongARM CPU's not implementing CTR

Previous RFCs:
[1] https://lkml.org/lkml/2014/1/8/523
[2] https://lkml.org/lkml/2014/2/7/654
[3] https://lkml.org/lkml/2014/2/19/391

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org

Sudeep Holla (9):
  drivers: base: add new class "cpu" to group cpu devices
  drivers: base: support cpu cache information interface to userspace
    via sysfs
  ia64: move cacheinfo sysfs to generic cacheinfo infrastructure
  s390: move cacheinfo sysfs to generic cacheinfo infrastructure
  x86: move cacheinfo sysfs to generic cacheinfo infrastructure
  powerpc: move cacheinfo sysfs to generic cacheinfo infrastructure
  ARM64: kernel: add support for cpu cache information
  ARM: kernel: add support for cpu cache information
  ARM: kernel: add outer cache support for cacheinfo implementation

 Documentation/ABI/testing/sysfs-devices-system-cpu |  41 ++
 arch/arm/include/asm/outercache.h                  |   9 +
 arch/arm/kernel/Makefile                           |   1 +
 arch/arm/kernel/cacheinfo.c                        | 284 +++++++
 arch/arm/mm/Kconfig                                |  13 +
 arch/arm/mm/cache-l2x0.c                           |  35 +-
 arch/arm/mm/cache-tauros2.c                        |  35 +
 arch/arm/mm/cache-xsc3l2.c                         |  16 +
 arch/arm64/kernel/Makefile                         |   3 +-
 arch/arm64/kernel/cacheinfo.c                      | 142 ++++
 arch/ia64/kernel/topology.c                        | 401 ++--------
 arch/powerpc/kernel/cacheinfo.c                    | 813 +++------------------
 arch/powerpc/kernel/cacheinfo.h                    |   8 -
 arch/powerpc/kernel/sysfs.c                        |  12 +-
 arch/s390/kernel/cache.c                           | 388 +++-------
 arch/x86/kernel/cpu/intel_cacheinfo.c              | 680 +++++------------
 drivers/base/Makefile                              |   2 +-
 drivers/base/cacheinfo.c                           | 539 ++++++++++++++
 drivers/base/core.c                                |  39 +-
 drivers/base/cpu.c                                 |   7 +
 include/linux/cacheinfo.h                          |  73 ++
 include/linux/cpu.h                                |   2 +
 22 files changed, 1660 insertions(+), 1883 deletions(-)
 create mode 100644 arch/arm/kernel/cacheinfo.c
 create mode 100644 arch/arm64/kernel/cacheinfo.c
 delete mode 100644 arch/powerpc/kernel/cacheinfo.h
 create mode 100644 drivers/base/cacheinfo.c
 create mode 100644 include/linux/cacheinfo.h

-- 
1.8.3.2

[PATCH v2 6/9] powerpc: move cacheinfo sysfs to generic cacheinfo infrastructure

[Sudeep Holla]

From: Sudeep Holla <sudeep.holla@arm.com>

This patch removes the redundant sysfs cacheinfo code by making use of
the newly introduced generic cacheinfo infrastructure.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/cacheinfo.c | 813 +++++-----------------------------------
 arch/powerpc/kernel/cacheinfo.h |   8 -
 arch/powerpc/kernel/sysfs.c     |  12 +-
 3 files changed, 91 insertions(+), 742 deletions(-)
 delete mode 100644 arch/powerpc/kernel/cacheinfo.h

diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c
index 40198d50b4c2..b871c246d945 100644
--- a/arch/powerpc/kernel/cacheinfo.c
+++ b/arch/powerpc/kernel/cacheinfo.c
@@ -10,38 +10,10 @@
  * 2 as published by the Free Software Foundation.
  */
 
+#include <linux/cacheinfo.h>
 #include <linux/cpu.h>
-#include <linux/cpumask.h>
 #include <linux/kernel.h>
-#include <linux/kobject.h>
-#include <linux/list.h>
-#include <linux/notifier.h>
 #include <linux/of.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <asm/prom.h>
-
-#include "cacheinfo.h"
-
-/* per-cpu object for tracking:
- * - a "cache" kobject for the top-level directory
- * - a list of "index" objects representing the cpu's local cache hierarchy
- */
-struct cache_dir {
-	struct kobject *kobj; /* bare (not embedded) kobject for cache
-			       * directory */
-	struct cache_index_dir *index; /* list of index objects */
-};
-
-/* "index" object: each cpu's cache directory has an index
- * subdirectory corresponding to a cache object associated with the
- * cpu.  This object's lifetime is managed via the embedded kobject.
- */
-struct cache_index_dir {
-	struct kobject kobj;
-	struct cache_index_dir *next; /* next index in parent directory */
-	struct cache *cache;
-};
 
 /* Template for determining which OF properties to query for a given
  * cache type */
@@ -60,11 +32,6 @@ struct cache_type_info {
 	const char *nr_sets_prop;
 };
 
-/* These are used to index the cache_type_info array. */
-#define CACHE_TYPE_UNIFIED     0
-#define CACHE_TYPE_INSTRUCTION 1
-#define CACHE_TYPE_DATA        2
-
 static const struct cache_type_info cache_type_info[] = {
 	{
 		/* PowerPC Processor binding says the [di]-cache-*
@@ -92,231 +59,83 @@ static const struct cache_type_info cache_type_info[] = {
 	},
 };
 
-/* Cache object: each instance of this corresponds to a distinct cache
- * in the system.  There are separate objects for Harvard caches: one
- * each for instruction and data, and each refers to the same OF node.
- * The refcount of the OF node is elevated for the lifetime of the
- * cache object.  A cache object is released when its shared_cpu_map
- * is cleared (see cache_cpu_clear).
- *
- * A cache object is on two lists: an unsorted global list
- * (cache_list) of cache objects; and a singly-linked list
- * representing the local cache hierarchy, which is ordered by level
- * (e.g. L1d -> L1i -> L2 -> L3).
- */
-struct cache {
-	struct device_node *ofnode;    /* OF node for this cache, may be cpu */
-	struct cpumask shared_cpu_map; /* online CPUs using this cache */
-	int type;                      /* split cache disambiguation */
-	int level;                     /* level not explicit in device tree */
-	struct list_head list;         /* global list of cache objects */
-	struct cache *next_local;      /* next cache of >= level */
-};
-
-static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu);
-
-/* traversal/modification of this list occurs only at cpu hotplug time;
- * access is serialized by cpu hotplug locking
- */
-static LIST_HEAD(cache_list);
-
-static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k)
-{
-	return container_of(k, struct cache_index_dir, kobj);
-}
-
-static const char *cache_type_string(const struct cache *cache)
+static inline int get_cacheinfo_idx(enum cache_type type)
 {
-	return cache_type_info[cache->type].name;
-}
-
-static void cache_init(struct cache *cache, int type, int level,
-		       struct device_node *ofnode)
-{
-	cache->type = type;
-	cache->level = level;
-	cache->ofnode = of_node_get(ofnode);
-	INIT_LIST_HEAD(&cache->list);
-	list_add(&cache->list, &cache_list);
-}
-
-static struct cache *new_cache(int type, int level, struct device_node *ofnode)
-{
-	struct cache *cache;
-
-	cache = kzalloc(sizeof(*cache), GFP_KERNEL);
-	if (cache)
-		cache_init(cache, type, level, ofnode);
-
-	return cache;
-}
-
-static void release_cache_debugcheck(struct cache *cache)
-{
-	struct cache *iter;
-
-	list_for_each_entry(iter, &cache_list, list)
-		WARN_ONCE(iter->next_local == cache,
-			  "cache for %s(%s) refers to cache for %s(%s)\n",
-			  iter->ofnode->full_name,
-			  cache_type_string(iter),
-			  cache->ofnode->full_name,
-			  cache_type_string(cache));
-}
-
-static void release_cache(struct cache *cache)
-{
-	if (!cache)
-		return;
-
-	pr_debug("freeing L%d %s cache for %s\n", cache->level,
-		 cache_type_string(cache), cache->ofnode->full_name);
-
-	release_cache_debugcheck(cache);
-	list_del(&cache->list);
-	of_node_put(cache->ofnode);
-	kfree(cache);
-}
-
-static void cache_cpu_set(struct cache *cache, int cpu)
-{
-	struct cache *next = cache;
-
-	while (next) {
-		WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
-			  "CPU %i already accounted in %s(%s)\n",
-			  cpu, next->ofnode->full_name,
-			  cache_type_string(next));
-		cpumask_set_cpu(cpu, &next->shared_cpu_map);
-		next = next->next_local;
-	}
+	if (type == CACHE_TYPE_UNIFIED)
+		return 0;
+	else
+		return type;
 }
 
-static int cache_size(const struct cache *cache, unsigned int *ret)
+static void cache_size(struct cacheinfo *this_leaf)
 {
 	const char *propname;
 	const __be32 *cache_size;
+	int ct_idx;
 
-	propname = cache_type_info[cache->type].size_prop;
+	ct_idx = get_cacheinfo_idx(this_leaf->type);
+	propname = cache_type_info[ct_idx].size_prop;
 
-	cache_size = of_get_property(cache->ofnode, propname, NULL);
+	cache_size = of_get_property(this_leaf->of_node, propname, NULL);
 	if (!cache_size)
-		return -ENODEV;
-
-	*ret = of_read_number(cache_size, 1);
-	return 0;
-}
-
-static int cache_size_kb(const struct cache *cache, unsigned int *ret)
-{
-	unsigned int size;
-
-	if (cache_size(cache, &size))
-		return -ENODEV;
-
-	*ret = size / 1024;
-	return 0;
+		this_leaf->size = 0;
+	else
+		this_leaf->size = of_read_number(cache_size, 1);
 }
 
 /* not cache_line_size() because that's a macro in include/linux/cache.h */
-static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
+static void cache_get_line_size(struct cacheinfo *this_leaf)
 {
 	const __be32 *line_size;
-	int i, lim;
+	int i, lim, ct_idx;
 
-	lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
+	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++) {
 		const char *propname;
 
-		propname = cache_type_info[cache->type].line_size_props[i];
-		line_size = of_get_property(cache->ofnode, propname, NULL);
+		propname = cache_type_info[ct_idx].line_size_props[i];
+		line_size = of_get_property(this_leaf->of_node, propname, NULL);
 		if (line_size)
 			break;
 	}
 
 	if (!line_size)
-		return -ENODEV;
-
-	*ret = of_read_number(line_size, 1);
-	return 0;
+		this_leaf->coherency_line_size = 0;
+	else
+		this_leaf->coherency_line_size = of_read_number(line_size, 1);
 }
 
-static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
+static void cache_nr_sets(struct cacheinfo *this_leaf)
 {
 	const char *propname;
 	const __be32 *nr_sets;
+	int ct_idx;
 
-	propname = cache_type_info[cache->type].nr_sets_prop;
+	ct_idx = get_cacheinfo_idx(this_leaf->type);
+	propname = cache_type_info[ct_idx].nr_sets_prop;
 
-	nr_sets = of_get_property(cache->ofnode, propname, NULL);
+	nr_sets = of_get_property(this_leaf->of_node, propname, NULL);
 	if (!nr_sets)
-		return -ENODEV;
-
-	*ret = of_read_number(nr_sets, 1);
-	return 0;
+		this_leaf->number_of_sets = 0;
+	else
+		this_leaf->number_of_sets = of_read_number(nr_sets, 1);
 }
 
-static int cache_associativity(const struct cache *cache, unsigned int *ret)
+static void cache_associativity(struct cacheinfo *this_leaf)
 {
-	unsigned int line_size;
-	unsigned int nr_sets;
-	unsigned int size;
-
-	if (cache_nr_sets(cache, &nr_sets))
-		goto err;
+	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) {
-		*ret = 0;
-		return 0;
-	}
-
-	if (cache_get_line_size(cache, &line_size))
-		goto err;
-	if (cache_size(cache, &size))
-		goto err;
-
-	if (!(nr_sets > 0 && size > 0 && line_size > 0))
-		goto err;
-
-	*ret = (size / nr_sets) / line_size;
-	return 0;
-err:
-	return -ENODEV;
-}
-
-/* helper for dealing with split caches */
-static struct cache *cache_find_first_sibling(struct cache *cache)
-{
-	struct cache *iter;
-
-	if (cache->type == CACHE_TYPE_UNIFIED)
-		return cache;
-
-	list_for_each_entry(iter, &cache_list, list)
-		if (iter->ofnode == cache->ofnode && iter->next_local == cache)
-			return iter;
-
-	return cache;
-}
-
-/* return the first cache on a local list matching node */
-static struct cache *cache_lookup_by_node(const struct device_node *node)
-{
-	struct cache *cache = NULL;
-	struct cache *iter;
-
-	list_for_each_entry(iter, &cache_list, list) {
-		if (iter->ofnode != node)
-			continue;
-		cache = cache_find_first_sibling(iter);
-		break;
-	}
-
-	return cache;
+	if ((nr_sets == 1) || !(nr_sets > 0 && size > 0 && line_size > 0))
+		this_leaf->ways_of_associativity = 0;
+	else
+		this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 }
 
 static bool cache_node_is_unified(const struct device_node *np)
@@ -324,526 +143,74 @@ static bool cache_node_is_unified(const struct device_node *np)
 	return of_get_property(np, "cache-unified", NULL);
 }
 
-static struct cache *cache_do_one_devnode_unified(struct device_node *node,
-						  int level)
-{
-	struct cache *cache;
-
-	pr_debug("creating L%d ucache for %s\n", level, node->full_name);
-
-	cache = new_cache(CACHE_TYPE_UNIFIED, level, node);
-
-	return cache;
-}
-
-static struct cache *cache_do_one_devnode_split(struct device_node *node,
-						int level)
-{
-	struct cache *dcache, *icache;
-
-	pr_debug("creating L%d dcache and icache for %s\n", level,
-		 node->full_name);
-
-	dcache = new_cache(CACHE_TYPE_DATA, level, node);
-	icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
-
-	if (!dcache || !icache)
-		goto err;
-
-	dcache->next_local = icache;
-
-	return dcache;
-err:
-	release_cache(dcache);
-	release_cache(icache);
-	return NULL;
-}
-
-static struct cache *cache_do_one_devnode(struct device_node *node, int level)
-{
-	struct cache *cache;
-
-	if (cache_node_is_unified(node))
-		cache = cache_do_one_devnode_unified(node, level);
-	else
-		cache = cache_do_one_devnode_split(node, level);
-
-	return cache;
-}
-
-static struct cache *cache_lookup_or_instantiate(struct device_node *node,
-						 int level)
-{
-	struct cache *cache;
-
-	cache = cache_lookup_by_node(node);
-
-	WARN_ONCE(cache && cache->level != level,
-		  "cache level mismatch on lookup (got %d, expected %d)\n",
-		  cache->level, level);
-
-	if (!cache)
-		cache = cache_do_one_devnode(node, level);
-
-	return cache;
-}
-
-static void link_cache_lists(struct cache *smaller, struct cache *bigger)
-{
-	while (smaller->next_local) {
-		if (smaller->next_local == bigger)
-			return; /* already linked */
-		smaller = smaller->next_local;
-	}
-
-	smaller->next_local = bigger;
-}
-
-static void do_subsidiary_caches_debugcheck(struct cache *cache)
-{
-	WARN_ON_ONCE(cache->level != 1);
-	WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu"));
-}
-
-static void do_subsidiary_caches(struct cache *cache)
-{
-	struct device_node *subcache_node;
-	int level = cache->level;
-
-	do_subsidiary_caches_debugcheck(cache);
-
-	while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
-		struct cache *subcache;
-
-		level++;
-		subcache = cache_lookup_or_instantiate(subcache_node, level);
-		of_node_put(subcache_node);
-		if (!subcache)
-			break;
-
-		link_cache_lists(cache, subcache);
-		cache = subcache;
-	}
-}
-
-static struct cache *cache_chain_instantiate(unsigned int cpu_id)
-{
-	struct device_node *cpu_node;
-	struct cache *cpu_cache = NULL;
-
-	pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
-
-	cpu_node = of_get_cpu_node(cpu_id, NULL);
-	WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
-	if (!cpu_node)
-		goto out;
-
-	cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
-	if (!cpu_cache)
-		goto out;
-
-	do_subsidiary_caches(cpu_cache);
-
-	cache_cpu_set(cpu_cache, cpu_id);
-out:
-	of_node_put(cpu_node);
-
-	return cpu_cache;
-}
-
-static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id)
-{
-	struct cache_dir *cache_dir;
-	struct device *dev;
-	struct kobject *kobj = NULL;
-
-	dev = get_cpu_device(cpu_id);
-	WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id);
-	if (!dev)
-		goto err;
-
-	kobj = kobject_create_and_add("cache", &dev->kobj);
-	if (!kobj)
-		goto err;
-
-	cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
-	if (!cache_dir)
-		goto err;
-
-	cache_dir->kobj = kobj;
-
-	WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
-
-	per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
-
-	return cache_dir;
-err:
-	kobject_put(kobj);
-	return NULL;
-}
-
-static void cache_index_release(struct kobject *kobj)
-{
-	struct cache_index_dir *index;
-
-	index = kobj_to_cache_index_dir(kobj);
-
-	pr_debug("freeing index directory for L%d %s cache\n",
-		 index->cache->level, cache_type_string(index->cache));
-
-	kfree(index);
-}
-
-static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
+static void ci_leaf_init(struct cacheinfo *this_leaf,
+			 enum cache_type type, unsigned int level)
 {
-	struct kobj_attribute *kobj_attr;
-
-	kobj_attr = container_of(attr, struct kobj_attribute, attr);
-
-	return kobj_attr->show(k, kobj_attr, buf);
+	this_leaf->level = level;
+	this_leaf->type = type;
+	cache_size(this_leaf);
+	cache_get_line_size(this_leaf);
+	cache_nr_sets(this_leaf);
+	cache_associativity(this_leaf);
 }
 
-static struct cache *index_kobj_to_cache(struct kobject *k)
+int init_cache_level(unsigned int cpu)
 {
-	struct cache_index_dir *index;
+	struct device_node *np;
+	struct device *cpu_dev = get_cpu_device(cpu);
+	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+	unsigned int level = 0, leaves = 0;
 
-	index = kobj_to_cache_index_dir(k);
-
-	return index->cache;
-}
-
-static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int size_kb;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_size_kb(cache, &size_kb))
+	if (!cpu_dev) {
+		pr_err("No cpu device for CPU %d\n", cpu);
 		return -ENODEV;
-
-	return sprintf(buf, "%uK\n", size_kb);
-}
-
-static struct kobj_attribute cache_size_attr =
-	__ATTR(size, 0444, size_show, NULL);
-
-
-static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int line_size;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_get_line_size(cache, &line_size))
-		return -ENODEV;
-
-	return sprintf(buf, "%u\n", line_size);
-}
-
-static struct kobj_attribute cache_line_size_attr =
-	__ATTR(coherency_line_size, 0444, line_size_show, NULL);
-
-static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int nr_sets;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_nr_sets(cache, &nr_sets))
-		return -ENODEV;
-
-	return sprintf(buf, "%u\n", nr_sets);
-}
-
-static struct kobj_attribute cache_nr_sets_attr =
-	__ATTR(number_of_sets, 0444, nr_sets_show, NULL);
-
-static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int associativity;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_associativity(cache, &associativity))
-		return -ENODEV;
-
-	return sprintf(buf, "%u\n", associativity);
-}
-
-static struct kobj_attribute cache_assoc_attr =
-	__ATTR(ways_of_associativity, 0444, associativity_show, NULL);
-
-static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	return sprintf(buf, "%s\n", cache_type_string(cache));
-}
-
-static struct kobj_attribute cache_type_attr =
-	__ATTR(type, 0444, type_show, NULL);
-
-static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache_index_dir *index;
-	struct cache *cache;
-
-	index = kobj_to_cache_index_dir(k);
-	cache = index->cache;
-
-	return sprintf(buf, "%d\n", cache->level);
-}
-
-static struct kobj_attribute cache_level_attr =
-	__ATTR(level, 0444, level_show, NULL);
-
-static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache_index_dir *index;
-	struct cache *cache;
-	int len;
-	int n = 0;
-
-	index = kobj_to_cache_index_dir(k);
-	cache = index->cache;
-	len = PAGE_SIZE - 2;
-
-	if (len > 1) {
-		n = cpumask_scnprintf(buf, len, &cache->shared_cpu_map);
-		buf[n++] = '\n';
-		buf[n] = '\0';
 	}
-	return n;
-}
-
-static struct kobj_attribute cache_shared_cpu_map_attr =
-	__ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
-
-/* Attributes which should always be created -- the kobject/sysfs core
- * does this automatically via kobj_type->default_attrs.  This is the
- * minimum data required to uniquely identify a cache.
- */
-static struct attribute *cache_index_default_attrs[] = {
-	&cache_type_attr.attr,
-	&cache_level_attr.attr,
-	&cache_shared_cpu_map_attr.attr,
-	NULL,
-};
-
-/* Attributes which should be created if the cache device node has the
- * right properties -- see cacheinfo_create_index_opt_attrs
- */
-static struct kobj_attribute *cache_index_opt_attrs[] = {
-	&cache_size_attr,
-	&cache_line_size_attr,
-	&cache_nr_sets_attr,
-	&cache_assoc_attr,
-};
-
-static const struct sysfs_ops cache_index_ops = {
-	.show = cache_index_show,
-};
-
-static struct kobj_type cache_index_type = {
-	.release = cache_index_release,
-	.sysfs_ops = &cache_index_ops,
-	.default_attrs = cache_index_default_attrs,
-};
-
-static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
-{
-	const char *cache_name;
-	const char *cache_type;
-	struct cache *cache;
-	char *buf;
-	int i;
-
-	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!buf)
-		return;
-
-	cache = dir->cache;
-	cache_name = cache->ofnode->full_name;
-	cache_type = cache_type_string(cache);
-
-	/* We don't want to create an attribute that can't provide a
-	 * meaningful value.  Check the return value of each optional
-	 * attribute's ->show method before registering the
-	 * attribute.
-	 */
-	for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
-		struct kobj_attribute *attr;
-		ssize_t rc;
-
-		attr = cache_index_opt_attrs[i];
-
-		rc = attr->show(&dir->kobj, attr, buf);
-		if (rc <= 0) {
-			pr_debug("not creating %s attribute for "
-				 "%s(%s) (rc = %zd)\n",
-				 attr->attr.name, cache_name,
-				 cache_type, rc);
-			continue;
-		}
-		if (sysfs_create_file(&dir->kobj, &attr->attr))
-			pr_debug("could not create %s attribute for %s(%s)\n",
-				 attr->attr.name, cache_name, cache_type);
+	np = cpu_dev->of_node;
+	if (!np) {
+		pr_err("Failed to find cpu%d device node\n", cpu);
+		return -ENOENT;
 	}
 
-	kfree(buf);
-}
-
-static void cacheinfo_create_index_dir(struct cache *cache, int index,
-				       struct cache_dir *cache_dir)
-{
-	struct cache_index_dir *index_dir;
-	int rc;
-
-	index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
-	if (!index_dir)
-		goto err;
-
-	index_dir->cache = cache;
-
-	rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
-				  cache_dir->kobj, "index%d", index);
-	if (rc)
-		goto err;
-
-	index_dir->next = cache_dir->index;
-	cache_dir->index = index_dir;
-
-	cacheinfo_create_index_opt_attrs(index_dir);
-
-	return;
-err:
-	kfree(index_dir);
-}
-
-static void cacheinfo_sysfs_populate(unsigned int cpu_id,
-				     struct cache *cache_list)
-{
-	struct cache_dir *cache_dir;
-	struct cache *cache;
-	int index = 0;
-
-	cache_dir = cacheinfo_create_cache_dir(cpu_id);
-	if (!cache_dir)
-		return;
-
-	cache = cache_list;
-	while (cache) {
-		cacheinfo_create_index_dir(cache, index, cache_dir);
-		index++;
-		cache = cache->next_local;
+	while (np) {
+		leaves += cache_node_is_unified(np) ? 1 : 2;
+		level++;
+		of_node_put(np);
+		np = of_find_next_cache_node(np);
 	}
-}
+	this_cpu_ci->num_levels = level;
+	this_cpu_ci->num_leaves = leaves;
 
-void cacheinfo_cpu_online(unsigned int cpu_id)
-{
-	struct cache *cache;
-
-	cache = cache_chain_instantiate(cpu_id);
-	if (!cache)
-		return;
-
-	cacheinfo_sysfs_populate(cpu_id, cache);
-}
-
-/* functions needed to remove cache entry for cpu offline or suspend/resume */
-
-#if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \
-    defined(CONFIG_HOTPLUG_CPU)
-
-static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
-{
-	struct device_node *cpu_node;
-	struct cache *cache;
-
-	cpu_node = of_get_cpu_node(cpu_id, NULL);
-	WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
-	if (!cpu_node)
-		return NULL;
-
-	cache = cache_lookup_by_node(cpu_node);
-	of_node_put(cpu_node);
-
-	return cache;
+	return 0;
 }
 
-static void remove_index_dirs(struct cache_dir *cache_dir)
+int populate_cache_leaves(unsigned int cpu)
 {
-	struct cache_index_dir *index;
-
-	index = cache_dir->index;
+	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
+	struct device *cpu_dev = get_cpu_device(cpu);
+	struct device_node *np;
+	unsigned int level, idx;
 
-	while (index) {
-		struct cache_index_dir *next;
-
-		next = index->next;
-		kobject_put(&index->kobj);
-		index = next;
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		pr_err("Failed to find cpu%d device node\n", cpu);
+		return -ENOENT;
 	}
-}
-
-static void remove_cache_dir(struct cache_dir *cache_dir)
-{
-	remove_index_dirs(cache_dir);
 
-	/* Remove cache dir from sysfs */
-	kobject_del(cache_dir->kobj);
-
-	kobject_put(cache_dir->kobj);
-
-	kfree(cache_dir);
-}
-
-static void cache_cpu_clear(struct cache *cache, int cpu)
-{
-	while (cache) {
-		struct cache *next = cache->next_local;
-
-		WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map),
-			  "CPU %i not accounted in %s(%s)\n",
-			  cpu, cache->ofnode->full_name,
-			  cache_type_string(cache));
-
-		cpumask_clear_cpu(cpu, &cache->shared_cpu_map);
-
-		/* Release the cache object if all the cpus using it
-		 * are offline */
-		if (cpumask_empty(&cache->shared_cpu_map))
-			release_cache(cache);
-
-		cache = next;
+	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
+	     idx < this_cpu_ci->num_leaves; idx++, level++) {
+		if (!this_leaf)
+			return -EINVAL;
+
+		this_leaf->of_node = np;
+		if (cache_node_is_unified(np)) {
+			ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
+		} else {
+			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
+			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
+		}
+		np = of_find_next_cache_node(np);
 	}
+	return 0;
 }
 
-void cacheinfo_cpu_offline(unsigned int cpu_id)
-{
-	struct cache_dir *cache_dir;
-	struct cache *cache;
-
-	/* Prevent userspace from seeing inconsistent state - remove
-	 * the sysfs hierarchy first */
-	cache_dir = per_cpu(cache_dir_pcpu, cpu_id);
-
-	/* careful, sysfs population may have failed */
-	if (cache_dir)
-		remove_cache_dir(cache_dir);
-
-	per_cpu(cache_dir_pcpu, cpu_id) = NULL;
-
-	/* clear the CPU's bit in its cache chain, possibly freeing
-	 * cache objects */
-	cache = cache_lookup_by_cpu(cpu_id);
-	if (cache)
-		cache_cpu_clear(cache, cpu_id);
-}
-#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */
diff --git a/arch/powerpc/kernel/cacheinfo.h b/arch/powerpc/kernel/cacheinfo.h
deleted file mode 100644
index a7b74d36acd7..000000000000
--- a/arch/powerpc/kernel/cacheinfo.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef _PPC_CACHEINFO_H
-#define _PPC_CACHEINFO_H
-
-/* These are just hooks for sysfs.c to use. */
-extern void cacheinfo_cpu_online(unsigned int cpu_id);
-extern void cacheinfo_cpu_offline(unsigned int cpu_id);
-
-#endif /* _PPC_CACHEINFO_H */
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 67fd2fd2620a..6e9c5a8141bb 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -19,8 +19,6 @@
 #include <asm/pmc.h>
 #include <asm/firmware.h>
 
-#include "cacheinfo.h"
-
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>
 #include <asm/lppaca.h>
@@ -743,7 +741,6 @@ static void register_cpu_online(unsigned int cpu)
 		device_create_file(s, &dev_attr_altivec_idle_wait_time);
 	}
 #endif
-	cacheinfo_cpu_online(cpu);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -824,7 +821,6 @@ static void unregister_cpu_online(unsigned int cpu)
 		device_remove_file(s, &dev_attr_altivec_idle_wait_time);
 	}
 #endif
-	cacheinfo_cpu_offline(cpu);
 }
 
 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
@@ -988,8 +984,7 @@ static int __init topology_init(void)
 	int cpu;
 
 	register_nodes();
-
-	cpu_notifier_register_begin();
+	register_cpu_notifier(&sysfs_cpu_nb);
 
 	for_each_possible_cpu(cpu) {
 		struct cpu *c = &per_cpu(cpu_devices, cpu);
@@ -1013,11 +1008,6 @@ static int __init topology_init(void)
 		if (cpu_online(cpu))
 			register_cpu_online(cpu);
 	}
-
-	__register_cpu_notifier(&sysfs_cpu_nb);
-
-	cpu_notifier_register_done();
-
 #ifdef CONFIG_PPC64
 	sysfs_create_dscr_default();
 #endif /* CONFIG_PPC64 */
-- 
1.8.3.2

[PATCH v3 00/11] drivers: cacheinfo support

[Sudeep Holla]

From: Sudeep Holla <sudeep.holla@arm.com>

This series adds a generic cacheinfo support similar to topology. The
implementation is based on x86 cacheinfo support. Currently x86, powerpc,
ia64 and s390 have their own implementations. While adding similar support
to ARM and ARM64, here is the attempt to make it generic quite similar to
topology info support. It also adds the missing ABI documentation for
the cacheinfo sysfs which is already being used.

It moves all the existing different implementations on x86, ia64, powerpc
and s390 to use the generic cacheinfo infrastructure introduced here.
These changes on non-ARM platforms are only compile tested and tested on x86.

This series also adds support for ARM and ARM64 architectures based on
the generic support.

The code can be fetched from:
 git://linux-arm.org/linux-skn cacheinfo

Changes v2->v3:
	- Added {allocation,write}_policy instead of single attributes sysfs
	  (attributes retained on ia64 privately as it was used only on that)
	- factored out show_cpumap into separate helper in cpumask.h
	- populate cpu_{map,list} for non-DT system if they are not populated
	  by arch specific callbacks
	- removed use of sysfs *_show callback in cache_attrs_is_visible
	- all the review comments from Stephen Boyd implemented

Changes v1->v2:
	- removed custom device_{add,remove}_attrs, using is_visible callback
	  instead(suggested by GregKH)
	- arm64: changes as per MarkR review comments
	- Moved smp_call_function_single to architectures using it(arm, arm64,
	  x86) (suggested by Stephen Boyd)
	- arm (mostly changes as per RMK's review comments)
		- fixed to allow v7 + v6 build
		- l2 cache changes to remove extra structure
		- populated CTR for few StrongARM CPU's not implementing CTR

[v1] https://lkml.org/lkml/2014/6/25/603
[v2] https://lkml.org/lkml/2014/7/25/467

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org

Sudeep Holla (11):
  cpumask: factor out show_cpumap into separate helper function
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  drivers: base: add new class "cpu" to group cpu devices
  drivers: base: support cpu cache information interface to userspace
    via sysfs
  ia64: move cacheinfo sysfs to generic cacheinfo infrastructure
  s390: move cacheinfo sysfs to generic cacheinfo infrastructure
  x86: move cacheinfo sysfs to generic cacheinfo infrastructure
  powerpc: move cacheinfo sysfs to generic cacheinfo infrastructure
  ARM64: kernel: add support for cpu cache information
  ARM: kernel: add support for cpu cache information
  ARM: kernel: add outer cache support for cacheinfo implementation

 Documentation/ABI/testing/sysfs-devices-system-cpu |  47 ++
 arch/arm/include/asm/outercache.h                  |   9 +
 arch/arm/kernel/Makefile                           |   1 +
 arch/arm/kernel/cacheinfo.c                        | 287 ++++++++
 arch/arm/mm/Kconfig                                |  13 +
 arch/arm/mm/cache-l2x0.c                           |  35 +-
 arch/arm/mm/cache-tauros2.c                        |  36 +
 arch/arm/mm/cache-xsc3l2.c                         |  17 +
 arch/arm64/kernel/Makefile                         |   2 +-
 arch/arm64/kernel/cacheinfo.c                      | 142 ++++
 arch/ia64/kernel/topology.c                        | 421 +++--------
 arch/powerpc/kernel/cacheinfo.c                    | 812 +++------------------
 arch/powerpc/kernel/cacheinfo.h                    |   8 -
 arch/powerpc/kernel/sysfs.c                        |  12 +-
 arch/s390/kernel/cache.c                           | 388 +++-------
 arch/x86/kernel/cpu/intel_cacheinfo.c              | 709 +++++-------------
 arch/x86/kernel/cpu/perf_event_amd_iommu.c         |   5 +-
 arch/x86/kernel/cpu/perf_event_amd_uncore.c        |   6 +-
 arch/x86/kernel/cpu/perf_event_intel_rapl.c        |   6 +-
 arch/x86/kernel/cpu/perf_event_intel_uncore.c      |   6 +-
 drivers/acpi/acpi_pad.c                            |   6 +-
 drivers/base/Makefile                              |   2 +-
 drivers/base/cacheinfo.c                           | 543 ++++++++++++++
 drivers/base/core.c                                |  39 +-
 drivers/base/cpu.c                                 |  12 +-
 drivers/base/node.c                                |  14 +-
 drivers/base/topology.c                            |  71 +-
 drivers/pci/pci-sysfs.c                            |  39 +-
 include/linux/cacheinfo.h                          | 100 +++
 include/linux/cpu.h                                |   2 +
 include/linux/cpumask.h                            |  27 +
 31 files changed, 1826 insertions(+), 1991 deletions(-)
 create mode 100644 arch/arm/kernel/cacheinfo.c
 create mode 100644 arch/arm64/kernel/cacheinfo.c
 delete mode 100644 arch/powerpc/kernel/cacheinfo.h
 create mode 100644 drivers/base/cacheinfo.c
 create mode 100644 include/linux/cacheinfo.h

-- 
1.8.3.2

[PATCH v3 08/11] powerpc: move cacheinfo sysfs to generic cacheinfo infrastructure

[Sudeep Holla]

From: Sudeep Holla <sudeep.holla@arm.com>

This patch removes the redundant sysfs cacheinfo code by making use of
the newly introduced generic cacheinfo infrastructure.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/cacheinfo.c | 812 +++++-----------------------------------
 arch/powerpc/kernel/cacheinfo.h |   8 -
 arch/powerpc/kernel/sysfs.c     |  12 +-
 3 files changed, 90 insertions(+), 742 deletions(-)
 delete mode 100644 arch/powerpc/kernel/cacheinfo.h

diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c
index 40198d50b4c2..6845eb7fcc18 100644
--- a/arch/powerpc/kernel/cacheinfo.c
+++ b/arch/powerpc/kernel/cacheinfo.c
@@ -10,38 +10,10 @@
  * 2 as published by the Free Software Foundation.
  */
 
+#include <linux/cacheinfo.h>
 #include <linux/cpu.h>
-#include <linux/cpumask.h>
 #include <linux/kernel.h>
-#include <linux/kobject.h>
-#include <linux/list.h>
-#include <linux/notifier.h>
 #include <linux/of.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <asm/prom.h>
-
-#include "cacheinfo.h"
-
-/* per-cpu object for tracking:
- * - a "cache" kobject for the top-level directory
- * - a list of "index" objects representing the cpu's local cache hierarchy
- */
-struct cache_dir {
-	struct kobject *kobj; /* bare (not embedded) kobject for cache
-			       * directory */
-	struct cache_index_dir *index; /* list of index objects */
-};
-
-/* "index" object: each cpu's cache directory has an index
- * subdirectory corresponding to a cache object associated with the
- * cpu.  This object's lifetime is managed via the embedded kobject.
- */
-struct cache_index_dir {
-	struct kobject kobj;
-	struct cache_index_dir *next; /* next index in parent directory */
-	struct cache *cache;
-};
 
 /* Template for determining which OF properties to query for a given
  * cache type */
@@ -60,11 +32,6 @@ struct cache_type_info {
 	const char *nr_sets_prop;
 };
 
-/* These are used to index the cache_type_info array. */
-#define CACHE_TYPE_UNIFIED     0
-#define CACHE_TYPE_INSTRUCTION 1
-#define CACHE_TYPE_DATA        2
-
 static const struct cache_type_info cache_type_info[] = {
 	{
 		/* PowerPC Processor binding says the [di]-cache-*
@@ -92,231 +59,82 @@ static const struct cache_type_info cache_type_info[] = {
 	},
 };
 
-/* Cache object: each instance of this corresponds to a distinct cache
- * in the system.  There are separate objects for Harvard caches: one
- * each for instruction and data, and each refers to the same OF node.
- * The refcount of the OF node is elevated for the lifetime of the
- * cache object.  A cache object is released when its shared_cpu_map
- * is cleared (see cache_cpu_clear).
- *
- * A cache object is on two lists: an unsorted global list
- * (cache_list) of cache objects; and a singly-linked list
- * representing the local cache hierarchy, which is ordered by level
- * (e.g. L1d -> L1i -> L2 -> L3).
- */
-struct cache {
-	struct device_node *ofnode;    /* OF node for this cache, may be cpu */
-	struct cpumask shared_cpu_map; /* online CPUs using this cache */
-	int type;                      /* split cache disambiguation */
-	int level;                     /* level not explicit in device tree */
-	struct list_head list;         /* global list of cache objects */
-	struct cache *next_local;      /* next cache of >= level */
-};
-
-static DEFINE_PER_CPU(struct cache_dir *, cache_dir_pcpu);
-
-/* traversal/modification of this list occurs only at cpu hotplug time;
- * access is serialized by cpu hotplug locking
- */
-static LIST_HEAD(cache_list);
-
-static struct cache_index_dir *kobj_to_cache_index_dir(struct kobject *k)
-{
-	return container_of(k, struct cache_index_dir, kobj);
-}
-
-static const char *cache_type_string(const struct cache *cache)
+static inline int get_cacheinfo_idx(enum cache_type type)
 {
-	return cache_type_info[cache->type].name;
-}
-
-static void cache_init(struct cache *cache, int type, int level,
-		       struct device_node *ofnode)
-{
-	cache->type = type;
-	cache->level = level;
-	cache->ofnode = of_node_get(ofnode);
-	INIT_LIST_HEAD(&cache->list);
-	list_add(&cache->list, &cache_list);
-}
-
-static struct cache *new_cache(int type, int level, struct device_node *ofnode)
-{
-	struct cache *cache;
-
-	cache = kzalloc(sizeof(*cache), GFP_KERNEL);
-	if (cache)
-		cache_init(cache, type, level, ofnode);
-
-	return cache;
-}
-
-static void release_cache_debugcheck(struct cache *cache)
-{
-	struct cache *iter;
-
-	list_for_each_entry(iter, &cache_list, list)
-		WARN_ONCE(iter->next_local == cache,
-			  "cache for %s(%s) refers to cache for %s(%s)\n",
-			  iter->ofnode->full_name,
-			  cache_type_string(iter),
-			  cache->ofnode->full_name,
-			  cache_type_string(cache));
-}
-
-static void release_cache(struct cache *cache)
-{
-	if (!cache)
-		return;
-
-	pr_debug("freeing L%d %s cache for %s\n", cache->level,
-		 cache_type_string(cache), cache->ofnode->full_name);
-
-	release_cache_debugcheck(cache);
-	list_del(&cache->list);
-	of_node_put(cache->ofnode);
-	kfree(cache);
-}
-
-static void cache_cpu_set(struct cache *cache, int cpu)
-{
-	struct cache *next = cache;
-
-	while (next) {
-		WARN_ONCE(cpumask_test_cpu(cpu, &next->shared_cpu_map),
-			  "CPU %i already accounted in %s(%s)\n",
-			  cpu, next->ofnode->full_name,
-			  cache_type_string(next));
-		cpumask_set_cpu(cpu, &next->shared_cpu_map);
-		next = next->next_local;
-	}
+	if (type == CACHE_TYPE_UNIFIED)
+		return 0;
+	return type;
 }
 
-static int cache_size(const struct cache *cache, unsigned int *ret)
+static void cache_size(struct cacheinfo *this_leaf)
 {
 	const char *propname;
 	const __be32 *cache_size;
+	int ct_idx;
 
-	propname = cache_type_info[cache->type].size_prop;
+	ct_idx = get_cacheinfo_idx(this_leaf->type);
+	propname = cache_type_info[ct_idx].size_prop;
 
-	cache_size = of_get_property(cache->ofnode, propname, NULL);
+	cache_size = of_get_property(this_leaf->of_node, propname, NULL);
 	if (!cache_size)
-		return -ENODEV;
-
-	*ret = of_read_number(cache_size, 1);
-	return 0;
-}
-
-static int cache_size_kb(const struct cache *cache, unsigned int *ret)
-{
-	unsigned int size;
-
-	if (cache_size(cache, &size))
-		return -ENODEV;
-
-	*ret = size / 1024;
-	return 0;
+		this_leaf->size = 0;
+	else
+		this_leaf->size = of_read_number(cache_size, 1);
 }
 
 /* not cache_line_size() because that's a macro in include/linux/cache.h */
-static int cache_get_line_size(const struct cache *cache, unsigned int *ret)
+static void cache_get_line_size(struct cacheinfo *this_leaf)
 {
 	const __be32 *line_size;
-	int i, lim;
+	int i, lim, ct_idx;
 
-	lim = ARRAY_SIZE(cache_type_info[cache->type].line_size_props);
+	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++) {
 		const char *propname;
 
-		propname = cache_type_info[cache->type].line_size_props[i];
-		line_size = of_get_property(cache->ofnode, propname, NULL);
+		propname = cache_type_info[ct_idx].line_size_props[i];
+		line_size = of_get_property(this_leaf->of_node, propname, NULL);
 		if (line_size)
 			break;
 	}
 
 	if (!line_size)
-		return -ENODEV;
-
-	*ret = of_read_number(line_size, 1);
-	return 0;
+		this_leaf->coherency_line_size = 0;
+	else
+		this_leaf->coherency_line_size = of_read_number(line_size, 1);
 }
 
-static int cache_nr_sets(const struct cache *cache, unsigned int *ret)
+static void cache_nr_sets(struct cacheinfo *this_leaf)
 {
 	const char *propname;
 	const __be32 *nr_sets;
+	int ct_idx;
 
-	propname = cache_type_info[cache->type].nr_sets_prop;
+	ct_idx = get_cacheinfo_idx(this_leaf->type);
+	propname = cache_type_info[ct_idx].nr_sets_prop;
 
-	nr_sets = of_get_property(cache->ofnode, propname, NULL);
+	nr_sets = of_get_property(this_leaf->of_node, propname, NULL);
 	if (!nr_sets)
-		return -ENODEV;
-
-	*ret = of_read_number(nr_sets, 1);
-	return 0;
+		this_leaf->number_of_sets = 0;
+	else
+		this_leaf->number_of_sets = of_read_number(nr_sets, 1);
 }
 
-static int cache_associativity(const struct cache *cache, unsigned int *ret)
+static void cache_associativity(struct cacheinfo *this_leaf)
 {
-	unsigned int line_size;
-	unsigned int nr_sets;
-	unsigned int size;
-
-	if (cache_nr_sets(cache, &nr_sets))
-		goto err;
+	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) {
-		*ret = 0;
-		return 0;
-	}
-
-	if (cache_get_line_size(cache, &line_size))
-		goto err;
-	if (cache_size(cache, &size))
-		goto err;
-
-	if (!(nr_sets > 0 && size > 0 && line_size > 0))
-		goto err;
-
-	*ret = (size / nr_sets) / line_size;
-	return 0;
-err:
-	return -ENODEV;
-}
-
-/* helper for dealing with split caches */
-static struct cache *cache_find_first_sibling(struct cache *cache)
-{
-	struct cache *iter;
-
-	if (cache->type == CACHE_TYPE_UNIFIED)
-		return cache;
-
-	list_for_each_entry(iter, &cache_list, list)
-		if (iter->ofnode == cache->ofnode && iter->next_local == cache)
-			return iter;
-
-	return cache;
-}
-
-/* return the first cache on a local list matching node */
-static struct cache *cache_lookup_by_node(const struct device_node *node)
-{
-	struct cache *cache = NULL;
-	struct cache *iter;
-
-	list_for_each_entry(iter, &cache_list, list) {
-		if (iter->ofnode != node)
-			continue;
-		cache = cache_find_first_sibling(iter);
-		break;
-	}
-
-	return cache;
+	if ((nr_sets == 1) || !(nr_sets > 0 && size > 0 && line_size > 0))
+		this_leaf->ways_of_associativity = 0;
+	else
+		this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 }
 
 static bool cache_node_is_unified(const struct device_node *np)
@@ -324,526 +142,74 @@ static bool cache_node_is_unified(const struct device_node *np)
 	return of_get_property(np, "cache-unified", NULL);
 }
 
-static struct cache *cache_do_one_devnode_unified(struct device_node *node,
-						  int level)
-{
-	struct cache *cache;
-
-	pr_debug("creating L%d ucache for %s\n", level, node->full_name);
-
-	cache = new_cache(CACHE_TYPE_UNIFIED, level, node);
-
-	return cache;
-}
-
-static struct cache *cache_do_one_devnode_split(struct device_node *node,
-						int level)
-{
-	struct cache *dcache, *icache;
-
-	pr_debug("creating L%d dcache and icache for %s\n", level,
-		 node->full_name);
-
-	dcache = new_cache(CACHE_TYPE_DATA, level, node);
-	icache = new_cache(CACHE_TYPE_INSTRUCTION, level, node);
-
-	if (!dcache || !icache)
-		goto err;
-
-	dcache->next_local = icache;
-
-	return dcache;
-err:
-	release_cache(dcache);
-	release_cache(icache);
-	return NULL;
-}
-
-static struct cache *cache_do_one_devnode(struct device_node *node, int level)
-{
-	struct cache *cache;
-
-	if (cache_node_is_unified(node))
-		cache = cache_do_one_devnode_unified(node, level);
-	else
-		cache = cache_do_one_devnode_split(node, level);
-
-	return cache;
-}
-
-static struct cache *cache_lookup_or_instantiate(struct device_node *node,
-						 int level)
-{
-	struct cache *cache;
-
-	cache = cache_lookup_by_node(node);
-
-	WARN_ONCE(cache && cache->level != level,
-		  "cache level mismatch on lookup (got %d, expected %d)\n",
-		  cache->level, level);
-
-	if (!cache)
-		cache = cache_do_one_devnode(node, level);
-
-	return cache;
-}
-
-static void link_cache_lists(struct cache *smaller, struct cache *bigger)
-{
-	while (smaller->next_local) {
-		if (smaller->next_local == bigger)
-			return; /* already linked */
-		smaller = smaller->next_local;
-	}
-
-	smaller->next_local = bigger;
-}
-
-static void do_subsidiary_caches_debugcheck(struct cache *cache)
-{
-	WARN_ON_ONCE(cache->level != 1);
-	WARN_ON_ONCE(strcmp(cache->ofnode->type, "cpu"));
-}
-
-static void do_subsidiary_caches(struct cache *cache)
-{
-	struct device_node *subcache_node;
-	int level = cache->level;
-
-	do_subsidiary_caches_debugcheck(cache);
-
-	while ((subcache_node = of_find_next_cache_node(cache->ofnode))) {
-		struct cache *subcache;
-
-		level++;
-		subcache = cache_lookup_or_instantiate(subcache_node, level);
-		of_node_put(subcache_node);
-		if (!subcache)
-			break;
-
-		link_cache_lists(cache, subcache);
-		cache = subcache;
-	}
-}
-
-static struct cache *cache_chain_instantiate(unsigned int cpu_id)
+static void ci_leaf_init(struct cacheinfo *this_leaf,
+			 enum cache_type type, unsigned int level)
 {
-	struct device_node *cpu_node;
-	struct cache *cpu_cache = NULL;
-
-	pr_debug("creating cache object(s) for CPU %i\n", cpu_id);
-
-	cpu_node = of_get_cpu_node(cpu_id, NULL);
-	WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
-	if (!cpu_node)
-		goto out;
-
-	cpu_cache = cache_lookup_or_instantiate(cpu_node, 1);
-	if (!cpu_cache)
-		goto out;
-
-	do_subsidiary_caches(cpu_cache);
-
-	cache_cpu_set(cpu_cache, cpu_id);
-out:
-	of_node_put(cpu_node);
-
-	return cpu_cache;
+	this_leaf->level = level;
+	this_leaf->type = type;
+	cache_size(this_leaf);
+	cache_get_line_size(this_leaf);
+	cache_nr_sets(this_leaf);
+	cache_associativity(this_leaf);
 }
 
-static struct cache_dir *cacheinfo_create_cache_dir(unsigned int cpu_id)
+int init_cache_level(unsigned int cpu)
 {
-	struct cache_dir *cache_dir;
-	struct device *dev;
-	struct kobject *kobj = NULL;
-
-	dev = get_cpu_device(cpu_id);
-	WARN_ONCE(!dev, "no dev for CPU %i\n", cpu_id);
-	if (!dev)
-		goto err;
-
-	kobj = kobject_create_and_add("cache", &dev->kobj);
-	if (!kobj)
-		goto err;
-
-	cache_dir = kzalloc(sizeof(*cache_dir), GFP_KERNEL);
-	if (!cache_dir)
-		goto err;
-
-	cache_dir->kobj = kobj;
-
-	WARN_ON_ONCE(per_cpu(cache_dir_pcpu, cpu_id) != NULL);
-
-	per_cpu(cache_dir_pcpu, cpu_id) = cache_dir;
+	struct device_node *np;
+	struct device *cpu_dev = get_cpu_device(cpu);
+	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+	unsigned int level = 0, leaves = 0;
 
-	return cache_dir;
-err:
-	kobject_put(kobj);
-	return NULL;
-}
-
-static void cache_index_release(struct kobject *kobj)
-{
-	struct cache_index_dir *index;
-
-	index = kobj_to_cache_index_dir(kobj);
-
-	pr_debug("freeing index directory for L%d %s cache\n",
-		 index->cache->level, cache_type_string(index->cache));
-
-	kfree(index);
-}
-
-static ssize_t cache_index_show(struct kobject *k, struct attribute *attr, char *buf)
-{
-	struct kobj_attribute *kobj_attr;
-
-	kobj_attr = container_of(attr, struct kobj_attribute, attr);
-
-	return kobj_attr->show(k, kobj_attr, buf);
-}
-
-static struct cache *index_kobj_to_cache(struct kobject *k)
-{
-	struct cache_index_dir *index;
-
-	index = kobj_to_cache_index_dir(k);
-
-	return index->cache;
-}
-
-static ssize_t size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int size_kb;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_size_kb(cache, &size_kb))
-		return -ENODEV;
-
-	return sprintf(buf, "%uK\n", size_kb);
-}
-
-static struct kobj_attribute cache_size_attr =
-	__ATTR(size, 0444, size_show, NULL);
-
-
-static ssize_t line_size_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int line_size;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_get_line_size(cache, &line_size))
-		return -ENODEV;
-
-	return sprintf(buf, "%u\n", line_size);
-}
-
-static struct kobj_attribute cache_line_size_attr =
-	__ATTR(coherency_line_size, 0444, line_size_show, NULL);
-
-static ssize_t nr_sets_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int nr_sets;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_nr_sets(cache, &nr_sets))
+	if (!cpu_dev) {
+		pr_err("No cpu device for CPU %d\n", cpu);
 		return -ENODEV;
-
-	return sprintf(buf, "%u\n", nr_sets);
-}
-
-static struct kobj_attribute cache_nr_sets_attr =
-	__ATTR(number_of_sets, 0444, nr_sets_show, NULL);
-
-static ssize_t associativity_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	unsigned int associativity;
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	if (cache_associativity(cache, &associativity))
-		return -ENODEV;
-
-	return sprintf(buf, "%u\n", associativity);
-}
-
-static struct kobj_attribute cache_assoc_attr =
-	__ATTR(ways_of_associativity, 0444, associativity_show, NULL);
-
-static ssize_t type_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache *cache;
-
-	cache = index_kobj_to_cache(k);
-
-	return sprintf(buf, "%s\n", cache_type_string(cache));
-}
-
-static struct kobj_attribute cache_type_attr =
-	__ATTR(type, 0444, type_show, NULL);
-
-static ssize_t level_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache_index_dir *index;
-	struct cache *cache;
-
-	index = kobj_to_cache_index_dir(k);
-	cache = index->cache;
-
-	return sprintf(buf, "%d\n", cache->level);
-}
-
-static struct kobj_attribute cache_level_attr =
-	__ATTR(level, 0444, level_show, NULL);
-
-static ssize_t shared_cpu_map_show(struct kobject *k, struct kobj_attribute *attr, char *buf)
-{
-	struct cache_index_dir *index;
-	struct cache *cache;
-	int len;
-	int n = 0;
-
-	index = kobj_to_cache_index_dir(k);
-	cache = index->cache;
-	len = PAGE_SIZE - 2;
-
-	if (len > 1) {
-		n = cpumask_scnprintf(buf, len, &cache->shared_cpu_map);
-		buf[n++] = '\n';
-		buf[n] = '\0';
 	}
-	return n;
-}
-
-static struct kobj_attribute cache_shared_cpu_map_attr =
-	__ATTR(shared_cpu_map, 0444, shared_cpu_map_show, NULL);
-
-/* Attributes which should always be created -- the kobject/sysfs core
- * does this automatically via kobj_type->default_attrs.  This is the
- * minimum data required to uniquely identify a cache.
- */
-static struct attribute *cache_index_default_attrs[] = {
-	&cache_type_attr.attr,
-	&cache_level_attr.attr,
-	&cache_shared_cpu_map_attr.attr,
-	NULL,
-};
-
-/* Attributes which should be created if the cache device node has the
- * right properties -- see cacheinfo_create_index_opt_attrs
- */
-static struct kobj_attribute *cache_index_opt_attrs[] = {
-	&cache_size_attr,
-	&cache_line_size_attr,
-	&cache_nr_sets_attr,
-	&cache_assoc_attr,
-};
-
-static const struct sysfs_ops cache_index_ops = {
-	.show = cache_index_show,
-};
-
-static struct kobj_type cache_index_type = {
-	.release = cache_index_release,
-	.sysfs_ops = &cache_index_ops,
-	.default_attrs = cache_index_default_attrs,
-};
-
-static void cacheinfo_create_index_opt_attrs(struct cache_index_dir *dir)
-{
-	const char *cache_name;
-	const char *cache_type;
-	struct cache *cache;
-	char *buf;
-	int i;
-
-	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!buf)
-		return;
-
-	cache = dir->cache;
-	cache_name = cache->ofnode->full_name;
-	cache_type = cache_type_string(cache);
-
-	/* We don't want to create an attribute that can't provide a
-	 * meaningful value.  Check the return value of each optional
-	 * attribute's ->show method before registering the
-	 * attribute.
-	 */
-	for (i = 0; i < ARRAY_SIZE(cache_index_opt_attrs); i++) {
-		struct kobj_attribute *attr;
-		ssize_t rc;
-
-		attr = cache_index_opt_attrs[i];
-
-		rc = attr->show(&dir->kobj, attr, buf);
-		if (rc <= 0) {
-			pr_debug("not creating %s attribute for "
-				 "%s(%s) (rc = %zd)\n",
-				 attr->attr.name, cache_name,
-				 cache_type, rc);
-			continue;
-		}
-		if (sysfs_create_file(&dir->kobj, &attr->attr))
-			pr_debug("could not create %s attribute for %s(%s)\n",
-				 attr->attr.name, cache_name, cache_type);
+	np = cpu_dev->of_node;
+	if (!np) {
+		pr_err("Failed to find cpu%d device node\n", cpu);
+		return -ENOENT;
 	}
 
-	kfree(buf);
-}
-
-static void cacheinfo_create_index_dir(struct cache *cache, int index,
-				       struct cache_dir *cache_dir)
-{
-	struct cache_index_dir *index_dir;
-	int rc;
-
-	index_dir = kzalloc(sizeof(*index_dir), GFP_KERNEL);
-	if (!index_dir)
-		goto err;
-
-	index_dir->cache = cache;
-
-	rc = kobject_init_and_add(&index_dir->kobj, &cache_index_type,
-				  cache_dir->kobj, "index%d", index);
-	if (rc)
-		goto err;
-
-	index_dir->next = cache_dir->index;
-	cache_dir->index = index_dir;
-
-	cacheinfo_create_index_opt_attrs(index_dir);
-
-	return;
-err:
-	kfree(index_dir);
-}
-
-static void cacheinfo_sysfs_populate(unsigned int cpu_id,
-				     struct cache *cache_list)
-{
-	struct cache_dir *cache_dir;
-	struct cache *cache;
-	int index = 0;
-
-	cache_dir = cacheinfo_create_cache_dir(cpu_id);
-	if (!cache_dir)
-		return;
-
-	cache = cache_list;
-	while (cache) {
-		cacheinfo_create_index_dir(cache, index, cache_dir);
-		index++;
-		cache = cache->next_local;
+	while (np) {
+		leaves += cache_node_is_unified(np) ? 1 : 2;
+		level++;
+		of_node_put(np);
+		np = of_find_next_cache_node(np);
 	}
-}
+	this_cpu_ci->num_levels = level;
+	this_cpu_ci->num_leaves = leaves;
 
-void cacheinfo_cpu_online(unsigned int cpu_id)
-{
-	struct cache *cache;
-
-	cache = cache_chain_instantiate(cpu_id);
-	if (!cache)
-		return;
-
-	cacheinfo_sysfs_populate(cpu_id, cache);
-}
-
-/* functions needed to remove cache entry for cpu offline or suspend/resume */
-
-#if (defined(CONFIG_PPC_PSERIES) && defined(CONFIG_SUSPEND)) || \
-    defined(CONFIG_HOTPLUG_CPU)
-
-static struct cache *cache_lookup_by_cpu(unsigned int cpu_id)
-{
-	struct device_node *cpu_node;
-	struct cache *cache;
-
-	cpu_node = of_get_cpu_node(cpu_id, NULL);
-	WARN_ONCE(!cpu_node, "no OF node found for CPU %i\n", cpu_id);
-	if (!cpu_node)
-		return NULL;
-
-	cache = cache_lookup_by_node(cpu_node);
-	of_node_put(cpu_node);
-
-	return cache;
+	return 0;
 }
 
-static void remove_index_dirs(struct cache_dir *cache_dir)
+int populate_cache_leaves(unsigned int cpu)
 {
-	struct cache_index_dir *index;
-
-	index = cache_dir->index;
+	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
+	struct device *cpu_dev = get_cpu_device(cpu);
+	struct device_node *np;
+	unsigned int level, idx;
 
-	while (index) {
-		struct cache_index_dir *next;
-
-		next = index->next;
-		kobject_put(&index->kobj);
-		index = next;
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		pr_err("Failed to find cpu%d device node\n", cpu);
+		return -ENOENT;
 	}
-}
-
-static void remove_cache_dir(struct cache_dir *cache_dir)
-{
-	remove_index_dirs(cache_dir);
 
-	/* Remove cache dir from sysfs */
-	kobject_del(cache_dir->kobj);
-
-	kobject_put(cache_dir->kobj);
-
-	kfree(cache_dir);
-}
-
-static void cache_cpu_clear(struct cache *cache, int cpu)
-{
-	while (cache) {
-		struct cache *next = cache->next_local;
-
-		WARN_ONCE(!cpumask_test_cpu(cpu, &cache->shared_cpu_map),
-			  "CPU %i not accounted in %s(%s)\n",
-			  cpu, cache->ofnode->full_name,
-			  cache_type_string(cache));
-
-		cpumask_clear_cpu(cpu, &cache->shared_cpu_map);
-
-		/* Release the cache object if all the cpus using it
-		 * are offline */
-		if (cpumask_empty(&cache->shared_cpu_map))
-			release_cache(cache);
-
-		cache = next;
+	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
+	     idx < this_cpu_ci->num_leaves; idx++, level++) {
+		if (!this_leaf)
+			return -EINVAL;
+
+		this_leaf->of_node = np;
+		if (cache_node_is_unified(np)) {
+			ci_leaf_init(this_leaf++, CACHE_TYPE_UNIFIED, level);
+		} else {
+			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
+			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
+		}
+		np = of_find_next_cache_node(np);
 	}
+	return 0;
 }
 
-void cacheinfo_cpu_offline(unsigned int cpu_id)
-{
-	struct cache_dir *cache_dir;
-	struct cache *cache;
-
-	/* Prevent userspace from seeing inconsistent state - remove
-	 * the sysfs hierarchy first */
-	cache_dir = per_cpu(cache_dir_pcpu, cpu_id);
-
-	/* careful, sysfs population may have failed */
-	if (cache_dir)
-		remove_cache_dir(cache_dir);
-
-	per_cpu(cache_dir_pcpu, cpu_id) = NULL;
-
-	/* clear the CPU's bit in its cache chain, possibly freeing
-	 * cache objects */
-	cache = cache_lookup_by_cpu(cpu_id);
-	if (cache)
-		cache_cpu_clear(cache, cpu_id);
-}
-#endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */
diff --git a/arch/powerpc/kernel/cacheinfo.h b/arch/powerpc/kernel/cacheinfo.h
deleted file mode 100644
index a7b74d36acd7..000000000000
--- a/arch/powerpc/kernel/cacheinfo.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef _PPC_CACHEINFO_H
-#define _PPC_CACHEINFO_H
-
-/* These are just hooks for sysfs.c to use. */
-extern void cacheinfo_cpu_online(unsigned int cpu_id);
-extern void cacheinfo_cpu_offline(unsigned int cpu_id);
-
-#endif /* _PPC_CACHEINFO_H */
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 67fd2fd2620a..6e9c5a8141bb 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -19,8 +19,6 @@
 #include <asm/pmc.h>
 #include <asm/firmware.h>
 
-#include "cacheinfo.h"
-
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>
 #include <asm/lppaca.h>
@@ -743,7 +741,6 @@ static void register_cpu_online(unsigned int cpu)
 		device_create_file(s, &dev_attr_altivec_idle_wait_time);
 	}
 #endif
-	cacheinfo_cpu_online(cpu);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -824,7 +821,6 @@ static void unregister_cpu_online(unsigned int cpu)
 		device_remove_file(s, &dev_attr_altivec_idle_wait_time);
 	}
 #endif
-	cacheinfo_cpu_offline(cpu);
 }
 
 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
@@ -988,8 +984,7 @@ static int __init topology_init(void)
 	int cpu;
 
 	register_nodes();
-
-	cpu_notifier_register_begin();
+	register_cpu_notifier(&sysfs_cpu_nb);
 
 	for_each_possible_cpu(cpu) {
 		struct cpu *c = &per_cpu(cpu_devices, cpu);
@@ -1013,11 +1008,6 @@ static int __init topology_init(void)
 		if (cpu_online(cpu))
 			register_cpu_online(cpu);
 	}
-
-	__register_cpu_notifier(&sysfs_cpu_nb);
-
-	cpu_notifier_register_done();
-
 #ifdef CONFIG_PPC64
 	sysfs_create_dscr_default();
 #endif /* CONFIG_PPC64 */
-- 
1.8.3.2