![Alexander Shishkin](/assets/img/avatar_default.png)
Readability: a postfix increment is used on a pointer which is not used anywhere afterwards, which may send the reader looking through the function one extra time. Drop the unnecessary increment. Reported-by: Alan Cox <alan.cox@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>
485 lines
11 KiB
C
485 lines
11 KiB
C
/*
|
|
* System Trace Module (STM) master/channel allocation policy management
|
|
* Copyright (c) 2014, Intel Corporation.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms and conditions of the GNU General Public License,
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
* more details.
|
|
*
|
|
* A master/channel allocation policy allows mapping string identifiers to
|
|
* master and channel ranges, where allocation can be done.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/module.h>
|
|
#include <linux/device.h>
|
|
#include <linux/configfs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/stm.h>
|
|
#include "stm.h"
|
|
|
|
/*
|
|
* STP Master/Channel allocation policy configfs layout.
|
|
*/
|
|
|
|
struct stp_policy {
|
|
struct config_group group;
|
|
struct stm_device *stm;
|
|
};
|
|
|
|
struct stp_policy_node {
|
|
struct config_group group;
|
|
struct stp_policy *policy;
|
|
unsigned int first_master;
|
|
unsigned int last_master;
|
|
unsigned int first_channel;
|
|
unsigned int last_channel;
|
|
};
|
|
|
|
static struct configfs_subsystem stp_policy_subsys;
|
|
|
|
void stp_policy_node_get_ranges(struct stp_policy_node *policy_node,
|
|
unsigned int *mstart, unsigned int *mend,
|
|
unsigned int *cstart, unsigned int *cend)
|
|
{
|
|
*mstart = policy_node->first_master;
|
|
*mend = policy_node->last_master;
|
|
*cstart = policy_node->first_channel;
|
|
*cend = policy_node->last_channel;
|
|
}
|
|
|
|
static inline char *stp_policy_node_name(struct stp_policy_node *policy_node)
|
|
{
|
|
return policy_node->group.cg_item.ci_name ? : "<none>";
|
|
}
|
|
|
|
static inline struct stp_policy *to_stp_policy(struct config_item *item)
|
|
{
|
|
return item ?
|
|
container_of(to_config_group(item), struct stp_policy, group) :
|
|
NULL;
|
|
}
|
|
|
|
static inline struct stp_policy_node *
|
|
to_stp_policy_node(struct config_item *item)
|
|
{
|
|
return item ?
|
|
container_of(to_config_group(item), struct stp_policy_node,
|
|
group) :
|
|
NULL;
|
|
}
|
|
|
|
static ssize_t
|
|
stp_policy_node_masters_show(struct config_item *item, char *page)
|
|
{
|
|
struct stp_policy_node *policy_node = to_stp_policy_node(item);
|
|
ssize_t count;
|
|
|
|
count = sprintf(page, "%u %u\n", policy_node->first_master,
|
|
policy_node->last_master);
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t
|
|
stp_policy_node_masters_store(struct config_item *item, const char *page,
|
|
size_t count)
|
|
{
|
|
struct stp_policy_node *policy_node = to_stp_policy_node(item);
|
|
unsigned int first, last;
|
|
struct stm_device *stm;
|
|
char *p = (char *)page;
|
|
ssize_t ret = -ENODEV;
|
|
|
|
if (sscanf(p, "%u %u", &first, &last) != 2)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&stp_policy_subsys.su_mutex);
|
|
stm = policy_node->policy->stm;
|
|
if (!stm)
|
|
goto unlock;
|
|
|
|
/* must be within [sw_start..sw_end], which is an inclusive range */
|
|
if (first > last || first < stm->data->sw_start ||
|
|
last > stm->data->sw_end) {
|
|
ret = -ERANGE;
|
|
goto unlock;
|
|
}
|
|
|
|
ret = count;
|
|
policy_node->first_master = first;
|
|
policy_node->last_master = last;
|
|
|
|
unlock:
|
|
mutex_unlock(&stp_policy_subsys.su_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
stp_policy_node_channels_show(struct config_item *item, char *page)
|
|
{
|
|
struct stp_policy_node *policy_node = to_stp_policy_node(item);
|
|
ssize_t count;
|
|
|
|
count = sprintf(page, "%u %u\n", policy_node->first_channel,
|
|
policy_node->last_channel);
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t
|
|
stp_policy_node_channels_store(struct config_item *item, const char *page,
|
|
size_t count)
|
|
{
|
|
struct stp_policy_node *policy_node = to_stp_policy_node(item);
|
|
unsigned int first, last;
|
|
struct stm_device *stm;
|
|
char *p = (char *)page;
|
|
ssize_t ret = -ENODEV;
|
|
|
|
if (sscanf(p, "%u %u", &first, &last) != 2)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&stp_policy_subsys.su_mutex);
|
|
stm = policy_node->policy->stm;
|
|
if (!stm)
|
|
goto unlock;
|
|
|
|
if (first > INT_MAX || last > INT_MAX || first > last ||
|
|
last >= stm->data->sw_nchannels) {
|
|
ret = -ERANGE;
|
|
goto unlock;
|
|
}
|
|
|
|
ret = count;
|
|
policy_node->first_channel = first;
|
|
policy_node->last_channel = last;
|
|
|
|
unlock:
|
|
mutex_unlock(&stp_policy_subsys.su_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void stp_policy_node_release(struct config_item *item)
|
|
{
|
|
kfree(to_stp_policy_node(item));
|
|
}
|
|
|
|
static struct configfs_item_operations stp_policy_node_item_ops = {
|
|
.release = stp_policy_node_release,
|
|
};
|
|
|
|
CONFIGFS_ATTR(stp_policy_node_, masters);
|
|
CONFIGFS_ATTR(stp_policy_node_, channels);
|
|
|
|
static struct configfs_attribute *stp_policy_node_attrs[] = {
|
|
&stp_policy_node_attr_masters,
|
|
&stp_policy_node_attr_channels,
|
|
NULL,
|
|
};
|
|
|
|
static struct config_item_type stp_policy_type;
|
|
static struct config_item_type stp_policy_node_type;
|
|
|
|
static struct config_group *
|
|
stp_policy_node_make(struct config_group *group, const char *name)
|
|
{
|
|
struct stp_policy_node *policy_node, *parent_node;
|
|
struct stp_policy *policy;
|
|
|
|
if (group->cg_item.ci_type == &stp_policy_type) {
|
|
policy = container_of(group, struct stp_policy, group);
|
|
} else {
|
|
parent_node = container_of(group, struct stp_policy_node,
|
|
group);
|
|
policy = parent_node->policy;
|
|
}
|
|
|
|
if (!policy->stm)
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
policy_node = kzalloc(sizeof(struct stp_policy_node), GFP_KERNEL);
|
|
if (!policy_node)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
config_group_init_type_name(&policy_node->group, name,
|
|
&stp_policy_node_type);
|
|
|
|
policy_node->policy = policy;
|
|
|
|
/* default values for the attributes */
|
|
policy_node->first_master = policy->stm->data->sw_start;
|
|
policy_node->last_master = policy->stm->data->sw_end;
|
|
policy_node->first_channel = 0;
|
|
policy_node->last_channel = policy->stm->data->sw_nchannels - 1;
|
|
|
|
return &policy_node->group;
|
|
}
|
|
|
|
static void
|
|
stp_policy_node_drop(struct config_group *group, struct config_item *item)
|
|
{
|
|
config_item_put(item);
|
|
}
|
|
|
|
static struct configfs_group_operations stp_policy_node_group_ops = {
|
|
.make_group = stp_policy_node_make,
|
|
.drop_item = stp_policy_node_drop,
|
|
};
|
|
|
|
static struct config_item_type stp_policy_node_type = {
|
|
.ct_item_ops = &stp_policy_node_item_ops,
|
|
.ct_group_ops = &stp_policy_node_group_ops,
|
|
.ct_attrs = stp_policy_node_attrs,
|
|
.ct_owner = THIS_MODULE,
|
|
};
|
|
|
|
/*
|
|
* Root group: policies.
|
|
*/
|
|
static ssize_t stp_policy_device_show(struct config_item *item,
|
|
char *page)
|
|
{
|
|
struct stp_policy *policy = to_stp_policy(item);
|
|
ssize_t count;
|
|
|
|
count = sprintf(page, "%s\n",
|
|
(policy && policy->stm) ?
|
|
policy->stm->data->name :
|
|
"<none>");
|
|
|
|
return count;
|
|
}
|
|
|
|
CONFIGFS_ATTR_RO(stp_policy_, device);
|
|
|
|
static struct configfs_attribute *stp_policy_attrs[] = {
|
|
&stp_policy_attr_device,
|
|
NULL,
|
|
};
|
|
|
|
void stp_policy_unbind(struct stp_policy *policy)
|
|
{
|
|
struct stm_device *stm = policy->stm;
|
|
|
|
/*
|
|
* stp_policy_release() will not call here if the policy is already
|
|
* unbound; other users should not either, as no link exists between
|
|
* this policy and anything else in that case
|
|
*/
|
|
if (WARN_ON_ONCE(!policy->stm))
|
|
return;
|
|
|
|
lockdep_assert_held(&stm->policy_mutex);
|
|
|
|
stm->policy = NULL;
|
|
policy->stm = NULL;
|
|
|
|
stm_put_device(stm);
|
|
}
|
|
|
|
static void stp_policy_release(struct config_item *item)
|
|
{
|
|
struct stp_policy *policy = to_stp_policy(item);
|
|
struct stm_device *stm = policy->stm;
|
|
|
|
/* a policy *can* be unbound and still exist in configfs tree */
|
|
if (!stm)
|
|
return;
|
|
|
|
mutex_lock(&stm->policy_mutex);
|
|
stp_policy_unbind(policy);
|
|
mutex_unlock(&stm->policy_mutex);
|
|
|
|
kfree(policy);
|
|
}
|
|
|
|
static struct configfs_item_operations stp_policy_item_ops = {
|
|
.release = stp_policy_release,
|
|
};
|
|
|
|
static struct configfs_group_operations stp_policy_group_ops = {
|
|
.make_group = stp_policy_node_make,
|
|
};
|
|
|
|
static struct config_item_type stp_policy_type = {
|
|
.ct_item_ops = &stp_policy_item_ops,
|
|
.ct_group_ops = &stp_policy_group_ops,
|
|
.ct_attrs = stp_policy_attrs,
|
|
.ct_owner = THIS_MODULE,
|
|
};
|
|
|
|
static struct config_group *
|
|
stp_policies_make(struct config_group *group, const char *name)
|
|
{
|
|
struct config_group *ret;
|
|
struct stm_device *stm;
|
|
char *devname, *p;
|
|
|
|
devname = kasprintf(GFP_KERNEL, "%s", name);
|
|
if (!devname)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/*
|
|
* node must look like <device_name>.<policy_name>, where
|
|
* <device_name> is the name of an existing stm device; may
|
|
* contain dots;
|
|
* <policy_name> is an arbitrary string; may not contain dots
|
|
*/
|
|
p = strrchr(devname, '.');
|
|
if (!p) {
|
|
kfree(devname);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
*p = '\0';
|
|
|
|
stm = stm_find_device(devname);
|
|
kfree(devname);
|
|
|
|
if (!stm)
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
mutex_lock(&stm->policy_mutex);
|
|
if (stm->policy) {
|
|
ret = ERR_PTR(-EBUSY);
|
|
goto unlock_policy;
|
|
}
|
|
|
|
stm->policy = kzalloc(sizeof(*stm->policy), GFP_KERNEL);
|
|
if (!stm->policy) {
|
|
ret = ERR_PTR(-ENOMEM);
|
|
goto unlock_policy;
|
|
}
|
|
|
|
config_group_init_type_name(&stm->policy->group, name,
|
|
&stp_policy_type);
|
|
stm->policy->stm = stm;
|
|
|
|
ret = &stm->policy->group;
|
|
|
|
unlock_policy:
|
|
mutex_unlock(&stm->policy_mutex);
|
|
|
|
if (IS_ERR(ret))
|
|
stm_put_device(stm);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct configfs_group_operations stp_policies_group_ops = {
|
|
.make_group = stp_policies_make,
|
|
};
|
|
|
|
static struct config_item_type stp_policies_type = {
|
|
.ct_group_ops = &stp_policies_group_ops,
|
|
.ct_owner = THIS_MODULE,
|
|
};
|
|
|
|
static struct configfs_subsystem stp_policy_subsys = {
|
|
.su_group = {
|
|
.cg_item = {
|
|
.ci_namebuf = "stp-policy",
|
|
.ci_type = &stp_policies_type,
|
|
},
|
|
},
|
|
};
|
|
|
|
/*
|
|
* Lock the policy mutex from the outside
|
|
*/
|
|
static struct stp_policy_node *
|
|
__stp_policy_node_lookup(struct stp_policy *policy, char *s)
|
|
{
|
|
struct stp_policy_node *policy_node, *ret;
|
|
struct list_head *head = &policy->group.cg_children;
|
|
struct config_item *item;
|
|
char *start, *end = s;
|
|
|
|
if (list_empty(head))
|
|
return NULL;
|
|
|
|
/* return the first entry if everything else fails */
|
|
item = list_entry(head->next, struct config_item, ci_entry);
|
|
ret = to_stp_policy_node(item);
|
|
|
|
next:
|
|
for (;;) {
|
|
start = strsep(&end, "/");
|
|
if (!start)
|
|
break;
|
|
|
|
if (!*start)
|
|
continue;
|
|
|
|
list_for_each_entry(item, head, ci_entry) {
|
|
policy_node = to_stp_policy_node(item);
|
|
|
|
if (!strcmp(start,
|
|
policy_node->group.cg_item.ci_name)) {
|
|
ret = policy_node;
|
|
|
|
if (!end)
|
|
goto out;
|
|
|
|
head = &policy_node->group.cg_children;
|
|
goto next;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
|
|
struct stp_policy_node *
|
|
stp_policy_node_lookup(struct stm_device *stm, char *s)
|
|
{
|
|
struct stp_policy_node *policy_node = NULL;
|
|
|
|
mutex_lock(&stp_policy_subsys.su_mutex);
|
|
|
|
mutex_lock(&stm->policy_mutex);
|
|
if (stm->policy)
|
|
policy_node = __stp_policy_node_lookup(stm->policy, s);
|
|
mutex_unlock(&stm->policy_mutex);
|
|
|
|
if (policy_node)
|
|
config_item_get(&policy_node->group.cg_item);
|
|
mutex_unlock(&stp_policy_subsys.su_mutex);
|
|
|
|
return policy_node;
|
|
}
|
|
|
|
void stp_policy_node_put(struct stp_policy_node *policy_node)
|
|
{
|
|
config_item_put(&policy_node->group.cg_item);
|
|
}
|
|
|
|
int __init stp_configfs_init(void)
|
|
{
|
|
int err;
|
|
|
|
config_group_init(&stp_policy_subsys.su_group);
|
|
mutex_init(&stp_policy_subsys.su_mutex);
|
|
err = configfs_register_subsystem(&stp_policy_subsys);
|
|
|
|
return err;
|
|
}
|
|
|
|
void __exit stp_configfs_exit(void)
|
|
{
|
|
configfs_unregister_subsystem(&stp_policy_subsys);
|
|
}
|