// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2020 Linaro Limited, All rights reserved.
* Author: Mike Leach <[email protected]>
*/
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "coresight-config.h"
#include "coresight-etm-perf.h"
#include "coresight-syscfg.h"
#include "coresight-syscfg-configfs.h"
/*
* cscfg_ API manages configurations and features for the entire coresight
* infrastructure.
*
* It allows the loading of configurations and features, and loads these into
* coresight devices as appropriate.
*/
/* protect the cscsg_data and device */
static DEFINE_MUTEX(cscfg_mutex);
/* only one of these */
static struct cscfg_manager *cscfg_mgr;
/* load features and configuations into the lists */
/* get name feature instance from a coresight device list of features */
static struct cscfg_feature_csdev *
cscfg_get_feat_csdev(struct coresight_device *csdev, const char *name)
{
struct cscfg_feature_csdev *feat_csdev = NULL;
list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node) {
if (strcmp(feat_csdev->feat_desc->name, name) == 0)
return feat_csdev;
}
return NULL;
}
/* allocate the device config instance - with max number of used features */
static struct cscfg_config_csdev *
cscfg_alloc_csdev_cfg(struct coresight_device *csdev, int nr_feats)
{
struct cscfg_config_csdev *config_csdev = NULL;
struct device *dev = csdev->dev.parent;
/* this is being allocated using the devm for the coresight device */
config_csdev = devm_kzalloc(dev,
offsetof(struct cscfg_config_csdev, feats_csdev[nr_feats]),
GFP_KERNEL);
if (!config_csdev)
return NULL;
config_csdev->csdev = csdev;
return config_csdev;
}
/* Load a config into a device if there are any feature matches between config and device */
static int cscfg_add_csdev_cfg(struct coresight_device *csdev,
struct cscfg_config_desc *config_desc)
{
struct cscfg_config_csdev *config_csdev = NULL;
struct cscfg_feature_csdev *feat_csdev;
unsigned long flags;
int i;
/* look at each required feature and see if it matches any feature on the device */
for (i = 0; i < config_desc->nr_feat_refs; i++) {
/* look for a matching name */
feat_csdev = cscfg_get_feat_csdev(csdev, config_desc->feat_ref_names[i]);
if (feat_csdev) {
/*
* At least one feature on this device matches the config
* add a config instance to the device and a reference to the feature.
*/
if (!config_csdev) {
config_csdev = cscfg_alloc_csdev_cfg(csdev,
config_desc->nr_feat_refs);
if (!config_csdev)
return -ENOMEM;
config_csdev->config_desc = config_desc;
}
config_csdev->feats_csdev[config_csdev->nr_feat++] = feat_csdev;
}
}
/* if matched features, add config to device.*/
if (config_csdev) {
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
list_add(&config_csdev->node, &csdev->config_csdev_list);
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
}
return 0;
}
/*
* Add the config to the set of registered devices - call with mutex locked.
* Iterates through devices - any device that matches one or more of the
* configuration features will load it, the others will ignore it.
*/
static int cscfg_add_cfg_to_csdevs(struct cscfg_config_desc *config_desc)
{
struct cscfg_registered_csdev *csdev_item;
int err;
list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) {
err = cscfg_add_csdev_cfg(csdev_item->csdev, config_desc);
if (err)
return err;
}
return 0;
}
/*
* Allocate a feature object for load into a csdev.
* memory allocated using the csdev->dev object using devm managed allocator.
*/
static struct cscfg_feature_csdev *
cscfg_alloc_csdev_feat(struct coresight_device *csdev, struct cscfg_feature_desc *feat_desc)
{
struct cscfg_feature_csdev *feat_csdev = NULL;
struct device *dev = csdev->dev.parent;
int i;
feat_csdev = devm_kzalloc(dev, sizeof(struct cscfg_feature_csdev), GFP_KERNEL);
if (!feat_csdev)
return NULL;
/* parameters are optional - could be 0 */
feat_csdev->nr_params = feat_desc->nr_params;
/*
* if we need parameters, zero alloc the space here, the load routine in
* the csdev device driver will fill out some information according to
* feature descriptor.
*/
if (feat_csdev->nr_params) {
feat_csdev->params_csdev = devm_kcalloc(dev, feat_csdev->nr_params,
sizeof(struct cscfg_parameter_csdev),
GFP_KERNEL);
if (!feat_csdev->params_csdev)
return NULL;
/*
* fill in the feature reference in the param - other fields
* handled by loader in csdev.
*/
for (i = 0; i < feat_csdev->nr_params; i++)
feat_csdev->params_csdev[i].feat_csdev = feat_csdev;
}
/*
* Always have registers to program - again the load routine in csdev device
* will fill out according to feature descriptor and device requirements.
*/
feat_csdev->nr_regs = feat_desc->nr_regs;
feat_csdev->regs_csdev = devm_kcalloc(dev, feat_csdev->nr_regs,
sizeof(struct cscfg_regval_csdev),
GFP_KERNEL);
if (!feat_csdev->regs_csdev)
return NULL;
/* load the feature default values */
feat_csdev->feat_desc = feat_desc;
feat_csdev->csdev = csdev;
return feat_csdev;
}
/* load one feature into one coresight device */
static int cscfg_load_feat_csdev(struct coresight_device *csdev,
struct cscfg_feature_desc *feat_desc,
struct cscfg_csdev_feat_ops *ops)
{
struct cscfg_feature_csdev *feat_csdev;
unsigned long flags;
int err;
if (!ops->load_feat)
return -EINVAL;
feat_csdev = cscfg_alloc_csdev_feat(csdev, feat_desc);
if (!feat_csdev)
return -ENOMEM;
/* load the feature into the device */
err = ops->load_feat(csdev, feat_csdev);
if (err)
return err;
/* add to internal csdev feature list & initialise using reset call */
cscfg_reset_feat(feat_csdev);
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
list_add(&feat_csdev->node, &csdev->feature_csdev_list);
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
return 0;
}
/*
* Add feature to any matching devices - call with mutex locked.
* Iterates through devices - any device that matches the feature will be
* called to load it.
*/
static int cscfg_add_feat_to_csdevs(struct cscfg_feature_desc *feat_desc)
{
struct cscfg_registered_csdev *csdev_item;
int err;
list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) {
if (csdev_item->match_flags & feat_desc->match_flags) {
err = cscfg_load_feat_csdev(csdev_item->csdev, feat_desc, &csdev_item->ops);
if (err)
return err;
}
}
return 0;
}
/* check feature list for a named feature - call with mutex locked. */
static bool cscfg_match_list_feat(const char *name)
{
struct cscfg_feature_desc *feat_desc;
list_for_each_entry(feat_desc, &cscfg_mgr->feat_desc_list, item) {
if (strcmp(feat_desc->name, name) == 0)
return true;
}
return false;
}
/* check all feat needed for cfg are in the list - call with mutex locked. */
static int cscfg_check_feat_for_cfg(struct cscfg_config_desc *config_desc)
{
int i;
for (i = 0; i < config_desc->nr_feat_refs; i++)
if (!cscfg_match_list_feat(config_desc->feat_ref_names[i]))
return -EINVAL;
return 0;
}
/*
* load feature - add to feature list.
*/
static int cscfg_load_feat(struct cscfg_feature_desc *feat_desc)
{
int err;
struct cscfg_feature_desc *feat_desc_exist;
/* new feature must have unique name */
list_for_each_entry(feat_desc_exist, &cscfg_mgr->feat_desc_list, item) {
if (!strcmp(feat_desc_exist->name, feat_desc->name))
return -EEXIST;
}
/* add feature to any matching registered devices */
err = cscfg_add_feat_to_csdevs(feat_desc);
if (err)
return err;
list_add(&feat_desc->item, &cscfg_mgr->feat_desc_list);
return 0;
}
/*
* load config into the system - validate used features exist then add to
* config list.
*/
static int cscfg_load_config(struct cscfg_config_desc *config_desc)
{
int err;
struct cscfg_config_desc *config_desc_exist;
/* new configuration must have a unique name */
list_for_each_entry(config_desc_exist, &cscfg_mgr->config_desc_list, item) {
if (!strcmp(config_desc_exist->name, config_desc->name))
return -EEXIST;
}
/* validate features are present */
err = cscfg_check_feat_for_cfg(config_desc);
if (err)
return err;
/* add config to any matching registered device */
err = cscfg_add_cfg_to_csdevs(config_desc);
if (err)
return err;
/* add config to perf fs to allow selection */
err = etm_perf_add_symlink_cscfg(cscfg_device(), config_desc);
if (err)
return err;
list_add(&config_desc->item, &cscfg_mgr->config_desc_list);
atomic_set(&config_desc->active_cnt, 0);
return 0;
}
/* get a feature descriptor by name */
const struct cscfg_feature_desc *cscfg_get_named_feat_desc(const char *name)
{
const struct cscfg_feature_desc *feat_desc = NULL, *feat_desc_item;
mutex_lock(&cscfg_mutex);
list_for_each_entry(feat_desc_item, &cscfg_mgr->feat_desc_list, item) {
if (strcmp(feat_desc_item->name, name) == 0) {
feat_desc = feat_desc_item;
break;
}
}
mutex_unlock(&cscfg_mutex);
return feat_desc;
}
/* called with cscfg_mutex held */
static struct cscfg_feature_csdev *
cscfg_csdev_get_feat_from_desc(struct coresight_device *csdev,
struct cscfg_feature_desc *feat_desc)
{
struct cscfg_feature_csdev *feat_csdev;
list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node) {
if (feat_csdev->feat_desc == feat_desc)
return feat_csdev;
}
return NULL;
}
int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc,
int param_idx, u64 value)
{
int err = 0;
struct cscfg_feature_csdev *feat_csdev;
struct cscfg_registered_csdev *csdev_item;
mutex_lock(&cscfg_mutex);
/* check if any config active & return busy */
if (atomic_read(&cscfg_mgr->sys_active_cnt)) {
err = -EBUSY;
goto unlock_exit;
}
/* set the value */
if ((param_idx < 0) || (param_idx >= feat_desc->nr_params)) {
err = -EINVAL;
goto unlock_exit;
}
feat_desc->params_desc[param_idx].value = value;
/* update loaded instances.*/
list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) {
feat_csdev = cscfg_csdev_get_feat_from_desc(csdev_item->csdev, feat_desc);
if (feat_csdev)
feat_csdev->params_csdev[param_idx].current_value = value;
}
unlock_exit:
mutex_unlock(&cscfg_mutex);
return err;
}
/*
* Conditionally up reference count on owner to prevent unload.
*
* module loaded configs need to be locked in to prevent premature unload.
*/
static int cscfg_owner_get(struct cscfg_load_owner_info *owner_info)
{
if ((owner_info->type == CSCFG_OWNER_MODULE) &&
(!try_module_get(owner_info->owner_handle)))
return -EINVAL;
return 0;
}
/* conditionally lower ref count on an owner */
static void cscfg_owner_put(struct cscfg_load_owner_info *owner_info)
{
if (owner_info->type == CSCFG_OWNER_MODULE)
module_put(owner_info->owner_handle);
}
static void cscfg_remove_owned_csdev_configs(struct coresight_device *csdev, void *load_owner)
{
struct cscfg_config_csdev *config_csdev, *tmp;
if (list_empty(&csdev->config_csdev_list))
return;
list_for_each_entry_safe(config_csdev, tmp, &csdev->config_csdev_list, node) {
if (config_csdev->config_desc->load_owner == load_owner)
list_del(&config_csdev->node);
}
}
static void cscfg_remove_owned_csdev_features(struct coresight_device *csdev, void *load_owner)
{
struct cscfg_feature_csdev *feat_csdev, *tmp;
if (list_empty(&csdev->feature_csdev_list))
return;
list_for_each_entry_safe(feat_csdev, tmp, &csdev->feature_csdev_list, node) {
if (feat_csdev->feat_desc->load_owner == load_owner)
list_del(&feat_csdev->node);
}
}
/*
* Unregister all configuration and features from configfs owned by load_owner.
* Although this is called without the list mutex being held, it is in the
* context of an unload operation which are strictly serialised,
* so the lists cannot change during this call.
*/
static void cscfg_fs_unregister_cfgs_feats(void *load_owner)
{
struct cscfg_config_desc *config_desc;
struct cscfg_feature_desc *feat_desc;
list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if (config_desc->load_owner == load_owner)
cscfg_configfs_del_config(config_desc);
}
list_for_each_entry(feat_desc, &cscfg_mgr->feat_desc_list, item) {
if (feat_desc->load_owner == load_owner)
cscfg_configfs_del_feature(feat_desc);
}
}
/*
* removal is relatively easy - just remove from all lists, anything that
* matches the owner. Memory for the descriptors will be managed by the owner,
* memory for the csdev items is devm_ allocated with the individual csdev
* devices.
*/
static void cscfg_unload_owned_cfgs_feats(void *load_owner)
{
struct cscfg_config_desc *config_desc, *cfg_tmp;
struct cscfg_feature_desc *feat_desc, *feat_tmp;
struct cscfg_registered_csdev *csdev_item;
lockdep_assert_held(&cscfg_mutex);
/* remove from each csdev instance feature and config lists */
list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) {
/*
* for each csdev, check the loaded lists and remove if
* referenced descriptor is owned
*/
cscfg_remove_owned_csdev_configs(csdev_item->csdev, load_owner);
cscfg_remove_owned_csdev_features(csdev_item->csdev, load_owner);
}
/* remove from the config descriptor lists */
list_for_each_entry_safe(config_desc, cfg_tmp, &cscfg_mgr->config_desc_list, item) {
if (config_desc->load_owner == load_owner) {
etm_perf_del_symlink_cscfg(config_desc);
list_del(&config_desc->item);
}
}
/* remove from the feature descriptor lists */
list_for_each_entry_safe(feat_desc, feat_tmp, &cscfg_mgr->feat_desc_list, item) {
if (feat_desc->load_owner == load_owner) {
list_del(&feat_desc->item);
}
}
}
/*
* load the features and configs to the lists - called with list mutex held
*/
static int cscfg_load_owned_cfgs_feats(struct cscfg_config_desc **config_descs,
struct cscfg_feature_desc **feat_descs,
struct cscfg_load_owner_info *owner_info)
{
int i, err;
lockdep_assert_held(&cscfg_mutex);
/* load features first */
if (feat_descs) {
for (i = 0; feat_descs[i]; i++) {
err = cscfg_load_feat(feat_descs[i]);
if (err) {
pr_err("coresight-syscfg: Failed to load feature %s\n",
feat_descs[i]->name);
return err;
}
feat_descs[i]->load_owner = owner_info;
}
}
/* next any configurations to check feature dependencies */
if (config_descs) {
for (i = 0; config_descs[i]; i++) {
err = cscfg_load_config(config_descs[i]);
if (err) {
pr_err("coresight-syscfg: Failed to load configuration %s\n",
config_descs[i]->name);
return err;
}
config_descs[i]->load_owner = owner_info;
config_descs[i]->available = false;
}
}
return 0;
}
/* set configurations as available to activate at the end of the load process */
static void cscfg_set_configs_available(struct cscfg_config_desc **config_descs)
{
int i;
lockdep_assert_held(&cscfg_mutex);
if (config_descs) {
for (i = 0; config_descs[i]; i++)
config_descs[i]->available = true;
}
}
/*
* Create and register each of the configurations and features with configfs.
* Called without mutex being held.
*/
static int cscfg_fs_register_cfgs_feats(struct cscfg_config_desc **config_descs,
struct cscfg_feature_desc **feat_descs)
{
int i, err;
if (feat_descs) {
for (i = 0; feat_descs[i]; i++) {
err = cscfg_configfs_add_feature(feat_descs[i]);
if (err)
return err;
}
}
if (config_descs) {
for (i = 0; config_descs[i]; i++) {
err = cscfg_configfs_add_config(config_descs[i]);
if (err)
return err;
}
}
return 0;
}
/**
* cscfg_load_config_sets - API function to load feature and config sets.
*
* Take a 0 terminated array of feature descriptors and/or configuration
* descriptors and load into the system.
* Features are loaded first to ensure configuration dependencies can be met.
*
* To facilitate dynamic loading and unloading, features and configurations
* have a "load_owner", to allow later unload by the same owner. An owner may
* be a loadable module or configuration dynamically created via configfs.
* As later loaded configurations can use earlier loaded features, creating load
* dependencies, a load order list is maintained. Unload is strictly in the
* reverse order to load.
*
* @config_descs: 0 terminated array of configuration descriptors.
* @feat_descs: 0 terminated array of feature descriptors.
* @owner_info: Information on the owner of this set.
*/
int cscfg_load_config_sets(struct cscfg_config_desc **config_descs,
struct cscfg_feature_desc **feat_descs,
struct cscfg_load_owner_info *owner_info)
{
int err = 0;
mutex_lock(&cscfg_mutex);
if (cscfg_mgr->load_state != CSCFG_NONE) {
mutex_unlock(&cscfg_mutex);
return -EBUSY;
}
cscfg_mgr->load_state = CSCFG_LOAD;
/* first load and add to the lists */
err = cscfg_load_owned_cfgs_feats(config_descs, feat_descs, owner_info);
if (err)
goto err_clean_load;
/* add the load owner to the load order list */
list_add_tail(&owner_info->item, &cscfg_mgr->load_order_list);
if (!list_is_singular(&cscfg_mgr->load_order_list)) {
/* lock previous item in load order list */
err = cscfg_owner_get(list_prev_entry(owner_info, item));
if (err)
goto err_clean_owner_list;
}
/*
* make visible to configfs - configfs manipulation must occur outside
* the list mutex lock to avoid circular lockdep issues with configfs
* built in mutexes and semaphores. This is safe as it is not possible
* to start a new load/unload operation till the current one is done.
*/
mutex_unlock(&cscfg_mutex);
/* create the configfs elements */
err = cscfg_fs_register_cfgs_feats(config_descs, feat_descs);
mutex_lock(&cscfg_mutex);
if (err)
goto err_clean_cfs;
/* mark any new configs as available for activation */
cscfg_set_configs_available(config_descs);
goto exit_unlock;
err_clean_cfs:
/* cleanup after error registering with configfs */
cscfg_fs_unregister_cfgs_feats(owner_info);
if (!list_is_singular(&cscfg_mgr->load_order_list))
cscfg_owner_put(list_prev_entry(owner_info, item));
err_clean_owner_list:
list_del(&owner_info->item);
err_clean_load:
cscfg_unload_owned_cfgs_feats(owner_info);
exit_unlock:
cscfg_mgr->load_state = CSCFG_NONE;
mutex_unlock(&cscfg_mutex);
return err;
}
EXPORT_SYMBOL_GPL(cscfg_load_config_sets);
/**
* cscfg_unload_config_sets - unload a set of configurations by owner.
*
* Dynamic unload of configuration and feature sets is done on the basis of
* the load owner of that set. Later loaded configurations can depend on
* features loaded earlier.
*
* Therefore, unload is only possible if:-
* 1) no configurations are active.
* 2) the set being unloaded was the last to be loaded to maintain dependencies.
*
* Once the unload operation commences, we disallow any configuration being
* made active until it is complete.
*
* @owner_info: Information on owner for set being unloaded.
*/
int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info)
{
int err = 0;
struct cscfg_load_owner_info *load_list_item = NULL;
mutex_lock(&cscfg_mutex);
if (cscfg_mgr->load_state != CSCFG_NONE) {
mutex_unlock(&cscfg_mutex);
return -EBUSY;
}
/* unload op in progress also prevents activation of any config */
cscfg_mgr->load_state = CSCFG_UNLOAD;
/* cannot unload if anything is active */
if (atomic_read(&cscfg_mgr->sys_active_cnt)) {
err = -EBUSY;
goto exit_unlock;
}
/* cannot unload if not last loaded in load order */
if (!list_empty(&cscfg_mgr->load_order_list)) {
load_list_item = list_last_entry(&cscfg_mgr->load_order_list,
struct cscfg_load_owner_info, item);
if (load_list_item != owner_info)
load_list_item = NULL;
}
if (!load_list_item) {
err = -EINVAL;
goto exit_unlock;
}
/* remove from configfs - again outside the scope of the list mutex */
mutex_unlock(&cscfg_mutex);
cscfg_fs_unregister_cfgs_feats(owner_info);
mutex_lock(&cscfg_mutex);
/* unload everything from lists belonging to load_owner */
cscfg_unload_owned_cfgs_feats(owner_info);
/* remove from load order list */
if (!list_is_singular(&cscfg_mgr->load_order_list)) {
/* unlock previous item in load order list */
cscfg_owner_put(list_prev_entry(owner_info, item));
}
list_del(&owner_info->item);
exit_unlock:
cscfg_mgr->load_state = CSCFG_NONE;
mutex_unlock(&cscfg_mutex);
return err;
}
EXPORT_SYMBOL_GPL(cscfg_unload_config_sets);
/* Handle coresight device registration and add configs and features to devices */
/* iterate through config lists and load matching configs to device */
static int cscfg_add_cfgs_csdev(struct coresight_device *csdev)
{
struct cscfg_config_desc *config_desc;
int err = 0;
list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
err = cscfg_add_csdev_cfg(csdev, config_desc);
if (err)
break;
}
return err;
}
/* iterate through feature lists and load matching features to device */
static int cscfg_add_feats_csdev(struct coresight_device *csdev,
u32 match_flags,
struct cscfg_csdev_feat_ops *ops)
{
struct cscfg_feature_desc *feat_desc;
int err = 0;
if (!ops->load_feat)
return -EINVAL;
list_for_each_entry(feat_desc, &cscfg_mgr->feat_desc_list, item) {
if (feat_desc->match_flags & match_flags) {
err = cscfg_load_feat_csdev(csdev, feat_desc, ops);
if (err)
break;
}
}
return err;
}
/* Add coresight device to list and copy its matching info */
static int cscfg_list_add_csdev(struct coresight_device *csdev,
u32 match_flags,
struct cscfg_csdev_feat_ops *ops)
{
struct cscfg_registered_csdev *csdev_item;
/* allocate the list entry structure */
csdev_item = kzalloc(sizeof(struct cscfg_registered_csdev), GFP_KERNEL);
if (!csdev_item)
return -ENOMEM;
csdev_item->csdev = csdev;
csdev_item->match_flags = match_flags;
csdev_item->ops.load_feat = ops->load_feat;
list_add(&csdev_item->item, &cscfg_mgr->csdev_desc_list);
INIT_LIST_HEAD(&csdev->feature_csdev_list);
INIT_LIST_HEAD(&csdev->config_csdev_list);
spin_lock_init(&csdev->cscfg_csdev_lock);
return 0;
}
/* remove a coresight device from the list and free data */
static void cscfg_list_remove_csdev(struct coresight_device *csdev)
{
struct cscfg_registered_csdev *csdev_item, *tmp;
list_for_each_entry_safe(csdev_item, tmp, &cscfg_mgr->csdev_desc_list, item) {
if (csdev_item->csdev == csdev) {
list_del(&csdev_item->item);
kfree(csdev_item);
break;
}
}
}
/**
* cscfg_register_csdev - register a coresight device with the syscfg manager.
*
* Registers the coresight device with the system. @match_flags used to check
* if the device is a match for registered features. Any currently registered
* configurations and features that match the device will be loaded onto it.
*
* @csdev: The coresight device to register.
* @match_flags: Matching information to load features.
* @ops: Standard operations supported by the device.
*/
int cscfg_register_csdev(struct coresight_device *csdev,
u32 match_flags,
struct cscfg_csdev_feat_ops *ops)
{
int ret = 0;
mutex_lock(&cscfg_mutex);
/* add device to list of registered devices */
ret = cscfg_list_add_csdev(csdev, match_flags, ops);
if (ret)
goto reg_csdev_unlock;
/* now load any registered features and configs matching the device. */
ret = cscfg_add_feats_csdev(csdev, match_flags, ops);
if (ret) {
cscfg_list_remove_csdev(csdev);
goto reg_csdev_unlock;
}
ret = cscfg_add_cfgs_csdev(csdev);
if (ret) {
cscfg_list_remove_csdev(csdev);
goto reg_csdev_unlock;
}
pr_info("CSCFG registered %s", dev_name(&csdev->dev));
reg_csdev_unlock:
mutex_unlock(&cscfg_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(cscfg_register_csdev);
/**
* cscfg_unregister_csdev - remove coresight device from syscfg manager.
*
* @csdev: Device to remove.
*/
void cscfg_unregister_csdev(struct coresight_device *csdev)
{
mutex_lock(&cscfg_mutex);
cscfg_list_remove_csdev(csdev);
mutex_unlock(&cscfg_mutex);
}
EXPORT_SYMBOL_GPL(cscfg_unregister_csdev);
/**
* cscfg_csdev_reset_feats - reset features for a CoreSight device.
*
* Resets all parameters and register values for any features loaded
* into @csdev to their default values.
*
* @csdev: The CoreSight device.
*/
void cscfg_csdev_reset_feats(struct coresight_device *csdev)
{
struct cscfg_feature_csdev *feat_csdev;
unsigned long flags;
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
if (list_empty(&csdev->feature_csdev_list))
goto unlock_exit;
list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node)
cscfg_reset_feat(feat_csdev);
unlock_exit:
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
}
EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats);
/*
* This activate configuration for either perf or sysfs. Perf can have multiple
* active configs, selected per event, sysfs is limited to one.
*
* Increments the configuration descriptor active count and the global active
* count.
*
* @cfg_hash: Hash value of the selected configuration name.
*/
static int _cscfg_activate_config(unsigned long cfg_hash)
{
struct cscfg_config_desc *config_desc;
int err = -EINVAL;
if (cscfg_mgr->load_state == CSCFG_UNLOAD)
return -EBUSY;
list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if ((unsigned long)config_desc->event_ea->var == cfg_hash) {
/* if we happen upon a partly loaded config, can't use it */
if (config_desc->available == false)
return -EBUSY;
/* must ensure that config cannot be unloaded in use */
err = cscfg_owner_get(config_desc->load_owner);
if (err)
break;
/*
* increment the global active count - control changes to
* active configurations
*/
atomic_inc(&cscfg_mgr->sys_active_cnt);
/*
* mark the descriptor as active so enable config on a
* device instance will use it
*/
atomic_inc(&config_desc->active_cnt);
err = 0;
dev_dbg(cscfg_device(), "Activate config %s.\n", config_desc->name);
break;
}
}
return err;
}
static void _cscfg_deactivate_config(unsigned long cfg_hash)
{
struct cscfg_config_desc *config_desc;
list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if ((unsigned long)config_desc->event_ea->var == cfg_hash) {
atomic_dec(&config_desc->active_cnt);
atomic_dec(&cscfg_mgr->sys_active_cnt);
cscfg_owner_put(config_desc->load_owner);
dev_dbg(cscfg_device(), "Deactivate config %s.\n", config_desc->name);
break;
}
}
}
/*
* called from configfs to set/clear the active configuration for use when
* using sysfs to control trace.
*/
int cscfg_config_sysfs_activate(struct cscfg_config_desc *config_desc, bool activate)
{
unsigned long cfg_hash;
int err = 0;
mutex_lock(&cscfg_mutex);
cfg_hash = (unsigned long)config_desc->event_ea->var;
if (activate) {
/* cannot be a current active value to activate this */
if (cscfg_mgr->sysfs_active_config) {
err = -EBUSY;
goto exit_unlock;
}
err = _cscfg_activate_config(cfg_hash);
if (!err)
cscfg_mgr->sysfs_active_config = cfg_hash;
} else {
/* disable if matching current value */
if (cscfg_mgr->sysfs_active_config == cfg_hash) {
_cscfg_deactivate_config(cfg_hash);
cscfg_mgr->sysfs_active_config = 0;
} else
err = -EINVAL;
}
exit_unlock:
mutex_unlock(&cscfg_mutex);
return err;
}
/* set the sysfs preset value */
void cscfg_config_sysfs_set_preset(int preset)
{
mutex_lock(&cscfg_mutex);
cscfg_mgr->sysfs_active_preset = preset;
mutex_unlock(&cscfg_mutex);
}
/*
* Used by a device to get the config and preset selected as active in configfs,
* when using sysfs to control trace.
*/
void cscfg_config_sysfs_get_active_cfg(unsigned long *cfg_hash, int *preset)
{
mutex_lock(&cscfg_mutex);
*preset = cscfg_mgr->sysfs_active_preset;
*cfg_hash = cscfg_mgr->sysfs_active_config;
mutex_unlock(&cscfg_mutex);
}
EXPORT_SYMBOL_GPL(cscfg_config_sysfs_get_active_cfg);
/**
* cscfg_activate_config - Mark a configuration descriptor as active.
*
* This will be seen when csdev devices are enabled in the system.
* Only activated configurations can be enabled on individual devices.
* Activation protects the configuration from alteration or removal while
* active.
*
* Selection by hash value - generated from the configuration name when it
* was loaded and added to the cs_etm/configurations file system for selection
* by perf.
*
* @cfg_hash: Hash value of the selected configuration name.
*/
int cscfg_activate_config(unsigned long cfg_hash)
{
int err = 0;
mutex_lock(&cscfg_mutex);
err = _cscfg_activate_config(cfg_hash);
mutex_unlock(&cscfg_mutex);
return err;
}
EXPORT_SYMBOL_GPL(cscfg_activate_config);
/**
* cscfg_deactivate_config - Mark a config descriptor as inactive.
*
* Decrement the configuration and global active counts.
*
* @cfg_hash: Hash value of the selected configuration name.
*/
void cscfg_deactivate_config(unsigned long cfg_hash)
{
mutex_lock(&cscfg_mutex);
_cscfg_deactivate_config(cfg_hash);
mutex_unlock(&cscfg_mutex);
}
EXPORT_SYMBOL_GPL(cscfg_deactivate_config);
/**
* cscfg_csdev_enable_active_config - Enable matching active configuration for device.
*
* Enables the configuration selected by @cfg_hash if the configuration is supported
* on the device and has been activated.
*
* If active and supported the CoreSight device @csdev will be programmed with the
* configuration, using @preset parameters.
*
* Should be called before driver hardware enable for the requested device, prior to
* programming and enabling the physical hardware.
*
* @csdev: CoreSight device to program.
* @cfg_hash: Selector for the configuration.
* @preset: Preset parameter values to use, 0 for current / default values.
*/
int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
unsigned long cfg_hash, int preset)
{
struct cscfg_config_csdev *config_csdev_active = NULL, *config_csdev_item;
const struct cscfg_config_desc *config_desc;
unsigned long flags;
int err = 0;
/* quickly check global count */
if (!atomic_read(&cscfg_mgr->sys_active_cnt))
return 0;
/*
* Look for matching configuration - set the active configuration
* context if found.
*/
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
list_for_each_entry(config_csdev_item, &csdev->config_csdev_list, node) {
config_desc = config_csdev_item->config_desc;
if ((atomic_read(&config_desc->active_cnt)) &&
((unsigned long)config_desc->event_ea->var == cfg_hash)) {
config_csdev_active = config_csdev_item;
csdev->active_cscfg_ctxt = (void *)config_csdev_active;
break;
}
}
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
/*
* If found, attempt to enable
*/
if (config_csdev_active) {
/*
* Call the generic routine that will program up the internal
* driver structures prior to programming up the hardware.
* This routine takes the driver spinlock saved in the configs.
*/
err = cscfg_csdev_enable_config(config_csdev_active, preset);
if (!err) {
/*
* Successful programming. Check the active_cscfg_ctxt
* pointer to ensure no pre-emption disabled it via
* cscfg_csdev_disable_active_config() before
* we could start.
*
* Set enabled if OK, err if not.
*/
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
if (csdev->active_cscfg_ctxt)
config_csdev_active->enabled = true;
else
err = -EBUSY;
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
}
}
return err;
}
EXPORT_SYMBOL_GPL(cscfg_csdev_enable_active_config);
/**
* cscfg_csdev_disable_active_config - disable an active config on the device.
*
* Disables the active configuration on the CoreSight device @csdev.
* Disable will save the values of any registers marked in the configurations
* as save on disable.
*
* Should be called after driver hardware disable for the requested device,
* after disabling the physical hardware and reading back registers.
*
* @csdev: The CoreSight device.
*/
void cscfg_csdev_disable_active_config(struct coresight_device *csdev)
{
struct cscfg_config_csdev *config_csdev;
unsigned long flags;
/*
* Check if we have an active config, and that it was successfully enabled.
* If it was not enabled, we have no work to do, otherwise mark as disabled.
* Clear the active config pointer.
*/
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
config_csdev = (struct cscfg_config_csdev *)csdev->active_cscfg_ctxt;
if (config_csdev) {
if (!config_csdev->enabled)
config_csdev = NULL;
else
config_csdev->enabled = false;
}
csdev->active_cscfg_ctxt = NULL;
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
/* true if there was an enabled active config */
if (config_csdev)
cscfg_csdev_disable_config(config_csdev);
}
EXPORT_SYMBOL_GPL(cscfg_csdev_disable_active_config);
/* Initialise system configuration management device. */
struct device *cscfg_device(void)
{
return cscfg_mgr ? &cscfg_mgr->dev : NULL;
}
/* Must have a release function or the kernel will complain on module unload */
static void cscfg_dev_release(struct device *dev)
{
mutex_lock(&cscfg_mutex);
kfree(cscfg_mgr);
cscfg_mgr = NULL;
mutex_unlock(&cscfg_mutex);
}
/* a device is needed to "own" some kernel elements such as sysfs entries. */
static int cscfg_create_device(void)
{
struct device *dev;
int err = -ENOMEM;
mutex_lock(&cscfg_mutex);
if (cscfg_mgr) {
err = -EINVAL;
goto create_dev_exit_unlock;
}
cscfg_mgr = kzalloc(sizeof(struct cscfg_manager), GFP_KERNEL);
if (!cscfg_mgr)
goto create_dev_exit_unlock;
/* initialise the cscfg_mgr structure */
INIT_LIST_HEAD(&cscfg_mgr->csdev_desc_list);
INIT_LIST_HEAD(&cscfg_mgr->feat_desc_list);
INIT_LIST_HEAD(&cscfg_mgr->config_desc_list);
INIT_LIST_HEAD(&cscfg_mgr->load_order_list);
atomic_set(&cscfg_mgr->sys_active_cnt, 0);
cscfg_mgr->load_state = CSCFG_NONE;
/* setup the device */
dev = cscfg_device();
dev->release = cscfg_dev_release;
dev->init_name = "cs_system_cfg";
err = device_register(dev);
if (err)
put_device(dev);
create_dev_exit_unlock:
mutex_unlock(&cscfg_mutex);
return err;
}
/*
* Loading and unloading is generally on user discretion.
* If exiting due to coresight module unload, we need to unload any configurations that remain,
* before we unregister the configfs intrastructure.
*
* Do this by walking the load_owner list and taking appropriate action, depending on the load
* owner type.
*/
static void cscfg_unload_cfgs_on_exit(void)
{
struct cscfg_load_owner_info *owner_info = NULL;
/*
* grab the mutex - even though we are exiting, some configfs files
* may still be live till we dump them, so ensure list data is
* protected from a race condition.
*/
mutex_lock(&cscfg_mutex);
while (!list_empty(&cscfg_mgr->load_order_list)) {
/* remove in reverse order of loading */
owner_info = list_last_entry(&cscfg_mgr->load_order_list,
struct cscfg_load_owner_info, item);
/* action according to type */
switch (owner_info->type) {
case CSCFG_OWNER_PRELOAD:
/*
* preloaded descriptors are statically allocated in
* this module - just need to unload dynamic items from
* csdev lists, and remove from configfs directories.
*/
pr_info("cscfg: unloading preloaded configurations\n");
break;
case CSCFG_OWNER_MODULE:
/*
* this is an error - the loadable module must have been unloaded prior
* to the coresight module unload. Therefore that module has not
* correctly unloaded configs in its own exit code.
* Nothing to do other than emit an error string as the static descriptor
* references we need to unload will have disappeared with the module.
*/
pr_err("cscfg: ERROR: prior module failed to unload configuration\n");
goto list_remove;
}
/* remove from configfs - outside the scope of the list mutex */
mutex_unlock(&cscfg_mutex);
cscfg_fs_unregister_cfgs_feats(owner_info);
mutex_lock(&cscfg_mutex);
/* Next unload from csdev lists. */
cscfg_unload_owned_cfgs_feats(owner_info);
list_remove:
/* remove from load order list */
list_del(&owner_info->item);
}
mutex_unlock(&cscfg_mutex);
}
static void cscfg_clear_device(void)
{
cscfg_unload_cfgs_on_exit();
cscfg_configfs_release(cscfg_mgr);
device_unregister(cscfg_device());
}
/* Initialise system config management API device */
int __init cscfg_init(void)
{
int err = 0;
/* create the device and init cscfg_mgr */
err = cscfg_create_device();
if (err)
return err;
/* initialise configfs subsystem */
err = cscfg_configfs_init(cscfg_mgr);
if (err)
goto exit_err;
/* preload built-in configurations */
err = cscfg_preload(THIS_MODULE);
if (err)
goto exit_err;
dev_info(cscfg_device(), "CoreSight Configuration manager initialised");
return 0;
exit_err:
cscfg_clear_device();
return err;
}
void cscfg_exit(void)
{
cscfg_clear_device();
}
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