linux/drivers/interconnect/core.c
Marek Szyprowski 017496af28 interconnect: fix memory trashing in of_count_icc_providers()
of_count_icc_providers() function uses for_each_available_child_of_node()
helper to recursively check all the available nodes. This helper already
properly handles child nodes' reference count, so there is no need to do
it explicitly. Remove the excessive call to of_node_put(). This fixes
memory trashing when CONFIG_OF_DYNAMIC is enabled (for example
arm/multi_v7_defconfig).

Fixes: b1d681d8d3 ("interconnect: Add sync state support")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20201119103746.32564-1-m.szyprowski@samsung.com
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-11-20 16:01:35 +02:00

1136 lines
26 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Interconnect framework core driver
*
* Copyright (c) 2017-2019, Linaro Ltd.
* Author: Georgi Djakov <georgi.djakov@linaro.org>
*/
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/interconnect.h>
#include <linux/interconnect-provider.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/overflow.h>
#include "internal.h"
#define CREATE_TRACE_POINTS
#include "trace.h"
static DEFINE_IDR(icc_idr);
static LIST_HEAD(icc_providers);
static int providers_count;
static bool synced_state;
static DEFINE_MUTEX(icc_lock);
static struct dentry *icc_debugfs_dir;
static void icc_summary_show_one(struct seq_file *s, struct icc_node *n)
{
if (!n)
return;
seq_printf(s, "%-42s %12u %12u\n",
n->name, n->avg_bw, n->peak_bw);
}
static int icc_summary_show(struct seq_file *s, void *data)
{
struct icc_provider *provider;
seq_puts(s, " node tag avg peak\n");
seq_puts(s, "--------------------------------------------------------------------\n");
mutex_lock(&icc_lock);
list_for_each_entry(provider, &icc_providers, provider_list) {
struct icc_node *n;
list_for_each_entry(n, &provider->nodes, node_list) {
struct icc_req *r;
icc_summary_show_one(s, n);
hlist_for_each_entry(r, &n->req_list, req_node) {
u32 avg_bw = 0, peak_bw = 0;
if (!r->dev)
continue;
if (r->enabled) {
avg_bw = r->avg_bw;
peak_bw = r->peak_bw;
}
seq_printf(s, " %-27s %12u %12u %12u\n",
dev_name(r->dev), r->tag, avg_bw, peak_bw);
}
}
}
mutex_unlock(&icc_lock);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(icc_summary);
static void icc_graph_show_link(struct seq_file *s, int level,
struct icc_node *n, struct icc_node *m)
{
seq_printf(s, "%s\"%d:%s\" -> \"%d:%s\"\n",
level == 2 ? "\t\t" : "\t",
n->id, n->name, m->id, m->name);
}
static void icc_graph_show_node(struct seq_file *s, struct icc_node *n)
{
seq_printf(s, "\t\t\"%d:%s\" [label=\"%d:%s",
n->id, n->name, n->id, n->name);
seq_printf(s, "\n\t\t\t|avg_bw=%ukBps", n->avg_bw);
seq_printf(s, "\n\t\t\t|peak_bw=%ukBps", n->peak_bw);
seq_puts(s, "\"]\n");
}
static int icc_graph_show(struct seq_file *s, void *data)
{
struct icc_provider *provider;
struct icc_node *n;
int cluster_index = 0;
int i;
seq_puts(s, "digraph {\n\trankdir = LR\n\tnode [shape = record]\n");
mutex_lock(&icc_lock);
/* draw providers as cluster subgraphs */
cluster_index = 0;
list_for_each_entry(provider, &icc_providers, provider_list) {
seq_printf(s, "\tsubgraph cluster_%d {\n", ++cluster_index);
if (provider->dev)
seq_printf(s, "\t\tlabel = \"%s\"\n",
dev_name(provider->dev));
/* draw nodes */
list_for_each_entry(n, &provider->nodes, node_list)
icc_graph_show_node(s, n);
/* draw internal links */
list_for_each_entry(n, &provider->nodes, node_list)
for (i = 0; i < n->num_links; ++i)
if (n->provider == n->links[i]->provider)
icc_graph_show_link(s, 2, n,
n->links[i]);
seq_puts(s, "\t}\n");
}
/* draw external links */
list_for_each_entry(provider, &icc_providers, provider_list)
list_for_each_entry(n, &provider->nodes, node_list)
for (i = 0; i < n->num_links; ++i)
if (n->provider != n->links[i]->provider)
icc_graph_show_link(s, 1, n,
n->links[i]);
mutex_unlock(&icc_lock);
seq_puts(s, "}");
return 0;
}
DEFINE_SHOW_ATTRIBUTE(icc_graph);
static struct icc_node *node_find(const int id)
{
return idr_find(&icc_idr, id);
}
static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
ssize_t num_nodes)
{
struct icc_node *node = dst;
struct icc_path *path;
int i;
path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL);
if (!path)
return ERR_PTR(-ENOMEM);
path->num_nodes = num_nodes;
for (i = num_nodes - 1; i >= 0; i--) {
node->provider->users++;
hlist_add_head(&path->reqs[i].req_node, &node->req_list);
path->reqs[i].node = node;
path->reqs[i].dev = dev;
path->reqs[i].enabled = true;
/* reference to previous node was saved during path traversal */
node = node->reverse;
}
return path;
}
static struct icc_path *path_find(struct device *dev, struct icc_node *src,
struct icc_node *dst)
{
struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
struct icc_node *n, *node = NULL;
struct list_head traverse_list;
struct list_head edge_list;
struct list_head visited_list;
size_t i, depth = 1;
bool found = false;
INIT_LIST_HEAD(&traverse_list);
INIT_LIST_HEAD(&edge_list);
INIT_LIST_HEAD(&visited_list);
list_add(&src->search_list, &traverse_list);
src->reverse = NULL;
do {
list_for_each_entry_safe(node, n, &traverse_list, search_list) {
if (node == dst) {
found = true;
list_splice_init(&edge_list, &visited_list);
list_splice_init(&traverse_list, &visited_list);
break;
}
for (i = 0; i < node->num_links; i++) {
struct icc_node *tmp = node->links[i];
if (!tmp) {
path = ERR_PTR(-ENOENT);
goto out;
}
if (tmp->is_traversed)
continue;
tmp->is_traversed = true;
tmp->reverse = node;
list_add_tail(&tmp->search_list, &edge_list);
}
}
if (found)
break;
list_splice_init(&traverse_list, &visited_list);
list_splice_init(&edge_list, &traverse_list);
/* count the hops including the source */
depth++;
} while (!list_empty(&traverse_list));
out:
/* reset the traversed state */
list_for_each_entry_reverse(n, &visited_list, search_list)
n->is_traversed = false;
if (found)
path = path_init(dev, dst, depth);
return path;
}
/*
* We want the path to honor all bandwidth requests, so the average and peak
* bandwidth requirements from each consumer are aggregated at each node.
* The aggregation is platform specific, so each platform can customize it by
* implementing its own aggregate() function.
*/
static int aggregate_requests(struct icc_node *node)
{
struct icc_provider *p = node->provider;
struct icc_req *r;
u32 avg_bw, peak_bw;
node->avg_bw = 0;
node->peak_bw = 0;
if (p->pre_aggregate)
p->pre_aggregate(node);
hlist_for_each_entry(r, &node->req_list, req_node) {
if (r->enabled) {
avg_bw = r->avg_bw;
peak_bw = r->peak_bw;
} else {
avg_bw = 0;
peak_bw = 0;
}
p->aggregate(node, r->tag, avg_bw, peak_bw,
&node->avg_bw, &node->peak_bw);
/* during boot use the initial bandwidth as a floor value */
if (!synced_state) {
node->avg_bw = max(node->avg_bw, node->init_avg);
node->peak_bw = max(node->peak_bw, node->init_peak);
}
}
return 0;
}
static int apply_constraints(struct icc_path *path)
{
struct icc_node *next, *prev = NULL;
struct icc_provider *p;
int ret = -EINVAL;
int i;
for (i = 0; i < path->num_nodes; i++) {
next = path->reqs[i].node;
p = next->provider;
/* both endpoints should be valid master-slave pairs */
if (!prev || (p != prev->provider && !p->inter_set)) {
prev = next;
continue;
}
/* set the constraints */
ret = p->set(prev, next);
if (ret)
goto out;
prev = next;
}
out:
return ret;
}
int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
{
*agg_avg += avg_bw;
*agg_peak = max(*agg_peak, peak_bw);
return 0;
}
EXPORT_SYMBOL_GPL(icc_std_aggregate);
/* of_icc_xlate_onecell() - Translate function using a single index.
* @spec: OF phandle args to map into an interconnect node.
* @data: private data (pointer to struct icc_onecell_data)
*
* This is a generic translate function that can be used to model simple
* interconnect providers that have one device tree node and provide
* multiple interconnect nodes. A single cell is used as an index into
* an array of icc nodes specified in the icc_onecell_data struct when
* registering the provider.
*/
struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec,
void *data)
{
struct icc_onecell_data *icc_data = data;
unsigned int idx = spec->args[0];
if (idx >= icc_data->num_nodes) {
pr_err("%s: invalid index %u\n", __func__, idx);
return ERR_PTR(-EINVAL);
}
return icc_data->nodes[idx];
}
EXPORT_SYMBOL_GPL(of_icc_xlate_onecell);
/**
* of_icc_get_from_provider() - Look-up interconnect node
* @spec: OF phandle args to use for look-up
*
* Looks for interconnect provider under the node specified by @spec and if
* found, uses xlate function of the provider to map phandle args to node.
*
* Returns a valid pointer to struct icc_node_data on success or ERR_PTR()
* on failure.
*/
struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec)
{
struct icc_node *node = ERR_PTR(-EPROBE_DEFER);
struct icc_node_data *data = NULL;
struct icc_provider *provider;
if (!spec)
return ERR_PTR(-EINVAL);
mutex_lock(&icc_lock);
list_for_each_entry(provider, &icc_providers, provider_list) {
if (provider->dev->of_node == spec->np) {
if (provider->xlate_extended) {
data = provider->xlate_extended(spec, provider->data);
if (!IS_ERR(data)) {
node = data->node;
break;
}
} else {
node = provider->xlate(spec, provider->data);
if (!IS_ERR(node))
break;
}
}
}
mutex_unlock(&icc_lock);
if (IS_ERR(node))
return ERR_CAST(node);
if (!data) {
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return ERR_PTR(-ENOMEM);
data->node = node;
}
return data;
}
EXPORT_SYMBOL_GPL(of_icc_get_from_provider);
static void devm_icc_release(struct device *dev, void *res)
{
icc_put(*(struct icc_path **)res);
}
struct icc_path *devm_of_icc_get(struct device *dev, const char *name)
{
struct icc_path **ptr, *path;
ptr = devres_alloc(devm_icc_release, sizeof(**ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
path = of_icc_get(dev, name);
if (!IS_ERR(path)) {
*ptr = path;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return path;
}
EXPORT_SYMBOL_GPL(devm_of_icc_get);
/**
* of_icc_get_by_index() - get a path handle from a DT node based on index
* @dev: device pointer for the consumer device
* @idx: interconnect path index
*
* This function will search for a path between two endpoints and return an
* icc_path handle on success. Use icc_put() to release constraints when they
* are not needed anymore.
* If the interconnect API is disabled, NULL is returned and the consumer
* drivers will still build. Drivers are free to handle this specifically,
* but they don't have to.
*
* Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
* when the API is disabled or the "interconnects" DT property is missing.
*/
struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
{
struct icc_path *path;
struct icc_node_data *src_data, *dst_data;
struct device_node *np;
struct of_phandle_args src_args, dst_args;
int ret;
if (!dev || !dev->of_node)
return ERR_PTR(-ENODEV);
np = dev->of_node;
/*
* When the consumer DT node do not have "interconnects" property
* return a NULL path to skip setting constraints.
*/
if (!of_find_property(np, "interconnects", NULL))
return NULL;
/*
* We use a combination of phandle and specifier for endpoint. For now
* lets support only global ids and extend this in the future if needed
* without breaking DT compatibility.
*/
ret = of_parse_phandle_with_args(np, "interconnects",
"#interconnect-cells", idx * 2,
&src_args);
if (ret)
return ERR_PTR(ret);
of_node_put(src_args.np);
ret = of_parse_phandle_with_args(np, "interconnects",
"#interconnect-cells", idx * 2 + 1,
&dst_args);
if (ret)
return ERR_PTR(ret);
of_node_put(dst_args.np);
src_data = of_icc_get_from_provider(&src_args);
if (IS_ERR(src_data)) {
dev_err_probe(dev, PTR_ERR(src_data), "error finding src node\n");
return ERR_CAST(src_data);
}
dst_data = of_icc_get_from_provider(&dst_args);
if (IS_ERR(dst_data)) {
dev_err_probe(dev, PTR_ERR(dst_data), "error finding dst node\n");
kfree(src_data);
return ERR_CAST(dst_data);
}
mutex_lock(&icc_lock);
path = path_find(dev, src_data->node, dst_data->node);
mutex_unlock(&icc_lock);
if (IS_ERR(path)) {
dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
goto free_icc_data;
}
if (src_data->tag && src_data->tag == dst_data->tag)
icc_set_tag(path, src_data->tag);
path->name = kasprintf(GFP_KERNEL, "%s-%s",
src_data->node->name, dst_data->node->name);
if (!path->name) {
kfree(path);
path = ERR_PTR(-ENOMEM);
}
free_icc_data:
kfree(src_data);
kfree(dst_data);
return path;
}
EXPORT_SYMBOL_GPL(of_icc_get_by_index);
/**
* of_icc_get() - get a path handle from a DT node based on name
* @dev: device pointer for the consumer device
* @name: interconnect path name
*
* This function will search for a path between two endpoints and return an
* icc_path handle on success. Use icc_put() to release constraints when they
* are not needed anymore.
* If the interconnect API is disabled, NULL is returned and the consumer
* drivers will still build. Drivers are free to handle this specifically,
* but they don't have to.
*
* Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
* when the API is disabled or the "interconnects" DT property is missing.
*/
struct icc_path *of_icc_get(struct device *dev, const char *name)
{
struct device_node *np;
int idx = 0;
if (!dev || !dev->of_node)
return ERR_PTR(-ENODEV);
np = dev->of_node;
/*
* When the consumer DT node do not have "interconnects" property
* return a NULL path to skip setting constraints.
*/
if (!of_find_property(np, "interconnects", NULL))
return NULL;
/*
* We use a combination of phandle and specifier for endpoint. For now
* lets support only global ids and extend this in the future if needed
* without breaking DT compatibility.
*/
if (name) {
idx = of_property_match_string(np, "interconnect-names", name);
if (idx < 0)
return ERR_PTR(idx);
}
return of_icc_get_by_index(dev, idx);
}
EXPORT_SYMBOL_GPL(of_icc_get);
/**
* icc_set_tag() - set an optional tag on a path
* @path: the path we want to tag
* @tag: the tag value
*
* This function allows consumers to append a tag to the requests associated
* with a path, so that a different aggregation could be done based on this tag.
*/
void icc_set_tag(struct icc_path *path, u32 tag)
{
int i;
if (!path)
return;
mutex_lock(&icc_lock);
for (i = 0; i < path->num_nodes; i++)
path->reqs[i].tag = tag;
mutex_unlock(&icc_lock);
}
EXPORT_SYMBOL_GPL(icc_set_tag);
/**
* icc_get_name() - Get name of the icc path
* @path: reference to the path returned by icc_get()
*
* This function is used by an interconnect consumer to get the name of the icc
* path.
*
* Returns a valid pointer on success, or NULL otherwise.
*/
const char *icc_get_name(struct icc_path *path)
{
if (!path)
return NULL;
return path->name;
}
EXPORT_SYMBOL_GPL(icc_get_name);
/**
* icc_set_bw() - set bandwidth constraints on an interconnect path
* @path: reference to the path returned by icc_get()
* @avg_bw: average bandwidth in kilobytes per second
* @peak_bw: peak bandwidth in kilobytes per second
*
* This function is used by an interconnect consumer to express its own needs
* in terms of bandwidth for a previously requested path between two endpoints.
* The requests are aggregated and each node is updated accordingly. The entire
* path is locked by a mutex to ensure that the set() is completed.
* The @path can be NULL when the "interconnects" DT properties is missing,
* which will mean that no constraints will be set.
*
* Returns 0 on success, or an appropriate error code otherwise.
*/
int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
{
struct icc_node *node;
u32 old_avg, old_peak;
size_t i;
int ret;
if (!path)
return 0;
if (WARN_ON(IS_ERR(path) || !path->num_nodes))
return -EINVAL;
mutex_lock(&icc_lock);
old_avg = path->reqs[0].avg_bw;
old_peak = path->reqs[0].peak_bw;
for (i = 0; i < path->num_nodes; i++) {
node = path->reqs[i].node;
/* update the consumer request for this path */
path->reqs[i].avg_bw = avg_bw;
path->reqs[i].peak_bw = peak_bw;
/* aggregate requests for this node */
aggregate_requests(node);
trace_icc_set_bw(path, node, i, avg_bw, peak_bw);
}
ret = apply_constraints(path);
if (ret) {
pr_debug("interconnect: error applying constraints (%d)\n",
ret);
for (i = 0; i < path->num_nodes; i++) {
node = path->reqs[i].node;
path->reqs[i].avg_bw = old_avg;
path->reqs[i].peak_bw = old_peak;
aggregate_requests(node);
}
apply_constraints(path);
}
mutex_unlock(&icc_lock);
trace_icc_set_bw_end(path, ret);
return ret;
}
EXPORT_SYMBOL_GPL(icc_set_bw);
static int __icc_enable(struct icc_path *path, bool enable)
{
int i;
if (!path)
return 0;
if (WARN_ON(IS_ERR(path) || !path->num_nodes))
return -EINVAL;
mutex_lock(&icc_lock);
for (i = 0; i < path->num_nodes; i++)
path->reqs[i].enabled = enable;
mutex_unlock(&icc_lock);
return icc_set_bw(path, path->reqs[0].avg_bw,
path->reqs[0].peak_bw);
}
int icc_enable(struct icc_path *path)
{
return __icc_enable(path, true);
}
EXPORT_SYMBOL_GPL(icc_enable);
int icc_disable(struct icc_path *path)
{
return __icc_enable(path, false);
}
EXPORT_SYMBOL_GPL(icc_disable);
/**
* icc_get() - return a handle for path between two endpoints
* @dev: the device requesting the path
* @src_id: source device port id
* @dst_id: destination device port id
*
* This function will search for a path between two endpoints and return an
* icc_path handle on success. Use icc_put() to release
* constraints when they are not needed anymore.
* If the interconnect API is disabled, NULL is returned and the consumer
* drivers will still build. Drivers are free to handle this specifically,
* but they don't have to.
*
* Return: icc_path pointer on success, ERR_PTR() on error or NULL if the
* interconnect API is disabled.
*/
struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id)
{
struct icc_node *src, *dst;
struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
mutex_lock(&icc_lock);
src = node_find(src_id);
if (!src)
goto out;
dst = node_find(dst_id);
if (!dst)
goto out;
path = path_find(dev, src, dst);
if (IS_ERR(path)) {
dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
goto out;
}
path->name = kasprintf(GFP_KERNEL, "%s-%s", src->name, dst->name);
if (!path->name) {
kfree(path);
path = ERR_PTR(-ENOMEM);
}
out:
mutex_unlock(&icc_lock);
return path;
}
EXPORT_SYMBOL_GPL(icc_get);
/**
* icc_put() - release the reference to the icc_path
* @path: interconnect path
*
* Use this function to release the constraints on a path when the path is
* no longer needed. The constraints will be re-aggregated.
*/
void icc_put(struct icc_path *path)
{
struct icc_node *node;
size_t i;
int ret;
if (!path || WARN_ON(IS_ERR(path)))
return;
ret = icc_set_bw(path, 0, 0);
if (ret)
pr_err("%s: error (%d)\n", __func__, ret);
mutex_lock(&icc_lock);
for (i = 0; i < path->num_nodes; i++) {
node = path->reqs[i].node;
hlist_del(&path->reqs[i].req_node);
if (!WARN_ON(!node->provider->users))
node->provider->users--;
}
mutex_unlock(&icc_lock);
kfree_const(path->name);
kfree(path);
}
EXPORT_SYMBOL_GPL(icc_put);
static struct icc_node *icc_node_create_nolock(int id)
{
struct icc_node *node;
/* check if node already exists */
node = node_find(id);
if (node)
return node;
node = kzalloc(sizeof(*node), GFP_KERNEL);
if (!node)
return ERR_PTR(-ENOMEM);
id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
if (id < 0) {
WARN(1, "%s: couldn't get idr\n", __func__);
kfree(node);
return ERR_PTR(id);
}
node->id = id;
return node;
}
/**
* icc_node_create() - create a node
* @id: node id
*
* Return: icc_node pointer on success, or ERR_PTR() on error
*/
struct icc_node *icc_node_create(int id)
{
struct icc_node *node;
mutex_lock(&icc_lock);
node = icc_node_create_nolock(id);
mutex_unlock(&icc_lock);
return node;
}
EXPORT_SYMBOL_GPL(icc_node_create);
/**
* icc_node_destroy() - destroy a node
* @id: node id
*/
void icc_node_destroy(int id)
{
struct icc_node *node;
mutex_lock(&icc_lock);
node = node_find(id);
if (node) {
idr_remove(&icc_idr, node->id);
WARN_ON(!hlist_empty(&node->req_list));
}
mutex_unlock(&icc_lock);
kfree(node);
}
EXPORT_SYMBOL_GPL(icc_node_destroy);
/**
* icc_link_create() - create a link between two nodes
* @node: source node id
* @dst_id: destination node id
*
* Create a link between two nodes. The nodes might belong to different
* interconnect providers and the @dst_id node might not exist (if the
* provider driver has not probed yet). So just create the @dst_id node
* and when the actual provider driver is probed, the rest of the node
* data is filled.
*
* Return: 0 on success, or an error code otherwise
*/
int icc_link_create(struct icc_node *node, const int dst_id)
{
struct icc_node *dst;
struct icc_node **new;
int ret = 0;
if (!node->provider)
return -EINVAL;
mutex_lock(&icc_lock);
dst = node_find(dst_id);
if (!dst) {
dst = icc_node_create_nolock(dst_id);
if (IS_ERR(dst)) {
ret = PTR_ERR(dst);
goto out;
}
}
new = krealloc(node->links,
(node->num_links + 1) * sizeof(*node->links),
GFP_KERNEL);
if (!new) {
ret = -ENOMEM;
goto out;
}
node->links = new;
node->links[node->num_links++] = dst;
out:
mutex_unlock(&icc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(icc_link_create);
/**
* icc_link_destroy() - destroy a link between two nodes
* @src: pointer to source node
* @dst: pointer to destination node
*
* Return: 0 on success, or an error code otherwise
*/
int icc_link_destroy(struct icc_node *src, struct icc_node *dst)
{
struct icc_node **new;
size_t slot;
int ret = 0;
if (IS_ERR_OR_NULL(src))
return -EINVAL;
if (IS_ERR_OR_NULL(dst))
return -EINVAL;
mutex_lock(&icc_lock);
for (slot = 0; slot < src->num_links; slot++)
if (src->links[slot] == dst)
break;
if (WARN_ON(slot == src->num_links)) {
ret = -ENXIO;
goto out;
}
src->links[slot] = src->links[--src->num_links];
new = krealloc(src->links, src->num_links * sizeof(*src->links),
GFP_KERNEL);
if (new)
src->links = new;
out:
mutex_unlock(&icc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(icc_link_destroy);
/**
* icc_node_add() - add interconnect node to interconnect provider
* @node: pointer to the interconnect node
* @provider: pointer to the interconnect provider
*/
void icc_node_add(struct icc_node *node, struct icc_provider *provider)
{
mutex_lock(&icc_lock);
node->provider = provider;
list_add_tail(&node->node_list, &provider->nodes);
/* get the initial bandwidth values and sync them with hardware */
if (provider->get_bw) {
provider->get_bw(node, &node->init_avg, &node->init_peak);
} else {
node->init_avg = INT_MAX;
node->init_peak = INT_MAX;
}
node->avg_bw = node->init_avg;
node->peak_bw = node->init_peak;
if (provider->aggregate)
provider->aggregate(node, 0, node->init_avg, node->init_peak,
&node->avg_bw, &node->peak_bw);
provider->set(node, node);
node->avg_bw = 0;
node->peak_bw = 0;
mutex_unlock(&icc_lock);
}
EXPORT_SYMBOL_GPL(icc_node_add);
/**
* icc_node_del() - delete interconnect node from interconnect provider
* @node: pointer to the interconnect node
*/
void icc_node_del(struct icc_node *node)
{
mutex_lock(&icc_lock);
list_del(&node->node_list);
mutex_unlock(&icc_lock);
}
EXPORT_SYMBOL_GPL(icc_node_del);
/**
* icc_nodes_remove() - remove all previously added nodes from provider
* @provider: the interconnect provider we are removing nodes from
*
* Return: 0 on success, or an error code otherwise
*/
int icc_nodes_remove(struct icc_provider *provider)
{
struct icc_node *n, *tmp;
if (WARN_ON(IS_ERR_OR_NULL(provider)))
return -EINVAL;
list_for_each_entry_safe_reverse(n, tmp, &provider->nodes, node_list) {
icc_node_del(n);
icc_node_destroy(n->id);
}
return 0;
}
EXPORT_SYMBOL_GPL(icc_nodes_remove);
/**
* icc_provider_add() - add a new interconnect provider
* @provider: the interconnect provider that will be added into topology
*
* Return: 0 on success, or an error code otherwise
*/
int icc_provider_add(struct icc_provider *provider)
{
if (WARN_ON(!provider->set))
return -EINVAL;
if (WARN_ON(!provider->xlate && !provider->xlate_extended))
return -EINVAL;
mutex_lock(&icc_lock);
INIT_LIST_HEAD(&provider->nodes);
list_add_tail(&provider->provider_list, &icc_providers);
mutex_unlock(&icc_lock);
dev_dbg(provider->dev, "interconnect provider added to topology\n");
return 0;
}
EXPORT_SYMBOL_GPL(icc_provider_add);
/**
* icc_provider_del() - delete previously added interconnect provider
* @provider: the interconnect provider that will be removed from topology
*
* Return: 0 on success, or an error code otherwise
*/
int icc_provider_del(struct icc_provider *provider)
{
mutex_lock(&icc_lock);
if (provider->users) {
pr_warn("interconnect provider still has %d users\n",
provider->users);
mutex_unlock(&icc_lock);
return -EBUSY;
}
if (!list_empty(&provider->nodes)) {
pr_warn("interconnect provider still has nodes\n");
mutex_unlock(&icc_lock);
return -EBUSY;
}
list_del(&provider->provider_list);
mutex_unlock(&icc_lock);
return 0;
}
EXPORT_SYMBOL_GPL(icc_provider_del);
static int of_count_icc_providers(struct device_node *np)
{
struct device_node *child;
int count = 0;
for_each_available_child_of_node(np, child) {
if (of_property_read_bool(child, "#interconnect-cells"))
count++;
count += of_count_icc_providers(child);
}
return count;
}
void icc_sync_state(struct device *dev)
{
struct icc_provider *p;
struct icc_node *n;
static int count;
count++;
if (count < providers_count)
return;
mutex_lock(&icc_lock);
synced_state = true;
list_for_each_entry(p, &icc_providers, provider_list) {
dev_dbg(p->dev, "interconnect provider is in synced state\n");
list_for_each_entry(n, &p->nodes, node_list) {
if (n->init_avg || n->init_peak) {
aggregate_requests(n);
p->set(n, n);
}
}
}
mutex_unlock(&icc_lock);
}
EXPORT_SYMBOL_GPL(icc_sync_state);
static int __init icc_init(void)
{
struct device_node *root = of_find_node_by_path("/");
providers_count = of_count_icc_providers(root);
of_node_put(root);
icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
debugfs_create_file("interconnect_summary", 0444,
icc_debugfs_dir, NULL, &icc_summary_fops);
debugfs_create_file("interconnect_graph", 0444,
icc_debugfs_dir, NULL, &icc_graph_fops);
return 0;
}
device_initcall(icc_init);
MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
MODULE_DESCRIPTION("Interconnect Driver Core");
MODULE_LICENSE("GPL v2");