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Merge "coresight: add support to enable multiple coresight paths"

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qctecmdr 2022-08-02 23:04:28 -07:00 committed by Gerrit - the friendly Code Review server
commit 25f6e27b02
1 changed files with 58 additions and 45 deletions
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103
drivers/hwtracing/coresight/coresight-core.c
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@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2012, The Linux Foundation. All rights reserved.
* Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
*/
#include <linux/kernel.h>
@ -37,18 +38,16 @@ struct coresight_node {
};
/*
* When operating Coresight drivers from the sysFS interface, only a single
* path can exist from a tracer (associated to a CPU) to a sink.
* struct coresight_path - path from source to sink
* @path: Address of path list.
* @link: hook to the list.
*/
static DEFINE_PER_CPU(struct list_head *, tracer_path);
struct coresight_path {
struct list_head *path;
struct list_head link;
};
/*
* As of this writing only a single STM can be found in CS topologies. Since
* there is no way to know if we'll ever see more and what kind of
* configuration they will enact, for the time being only define a single path
* for STM.
*/
static struct list_head *stm_path;
static LIST_HEAD(cs_active_paths);
/*
* When losing synchronisation a new barrier packet needs to be inserted at the
@ -355,6 +354,7 @@ static void coresight_disable_sink(struct coresight_device *csdev)
return;
coresight_control_assoc_ectdev(csdev, false);
csdev->enable = false;
csdev->activated = false;
}
static int coresight_enable_link(struct coresight_device *csdev,
@ -590,6 +590,20 @@ int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data)
goto out;
}
static struct coresight_device *coresight_get_source(struct list_head *path)
{
struct coresight_device *csdev;
if (!path)
return NULL;
csdev = list_first_entry(path, struct coresight_node, link)->csdev;
if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
return NULL;
return csdev;
}
struct coresight_device *coresight_get_sink(struct list_head *path)
{
struct coresight_device *csdev;
@ -1086,9 +1100,23 @@ static int coresight_validate_source(struct coresight_device *csdev,
return 0;
}
static int coresight_store_path(struct list_head *path)
{
struct coresight_path *node;
node = kzalloc(sizeof(struct coresight_path), GFP_KERNEL);
if (!node)
return -ENOMEM;
node->path = path;
list_add(&node->link, &cs_active_paths);
return 0;
}
int coresight_enable(struct coresight_device *csdev)
{
int cpu, ret = 0;
int ret = 0;
struct coresight_device *sink;
struct list_head *path;
enum coresight_dev_subtype_source subtype;
@ -1133,26 +1161,9 @@ int coresight_enable(struct coresight_device *csdev)
if (ret)
goto err_source;
switch (subtype) {
case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
/*
* When working from sysFS it is important to keep track
* of the paths that were created so that they can be
* undone in 'coresight_disable()'. Since there can only
* be a single session per tracer (when working from sysFS)
* a per-cpu variable will do just fine.
*/
cpu = source_ops(csdev)->cpu_id(csdev);
per_cpu(tracer_path, cpu) = path;
break;
case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
stm_path = path;
break;
default:
/* We can't be here */
break;
}
ret = coresight_store_path(path);
if (ret)
goto err_source;
out:
mutex_unlock(&coresight_mutex);
return ret;
@ -1168,8 +1179,11 @@ EXPORT_SYMBOL_GPL(coresight_enable);
void coresight_disable(struct coresight_device *csdev)
{
int cpu, ret;
int ret;
struct list_head *path = NULL;
struct coresight_path *cspath = NULL;
struct coresight_path *cspath_next = NULL;
struct coresight_device *src_csdev = NULL;
mutex_lock(&coresight_mutex);
@ -1180,21 +1194,20 @@ void coresight_disable(struct coresight_device *csdev)
if (!csdev->enable || !coresight_disable_source(csdev))
goto out;
switch (csdev->subtype.source_subtype) {
case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
cpu = source_ops(csdev)->cpu_id(csdev);
path = per_cpu(tracer_path, cpu);
per_cpu(tracer_path, cpu) = NULL;
break;
case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
path = stm_path;
stm_path = NULL;
break;
default:
/* We can't be here */
break;
list_for_each_entry_safe(cspath, cspath_next, &cs_active_paths, link) {
src_csdev = coresight_get_source(cspath->path);
if (!src_csdev)
continue;
if (src_csdev == csdev) {
path = cspath->path;
list_del(&cspath->link);
kfree(cspath);
}
}
if (path == NULL)
goto out;
coresight_disable_path(path);
coresight_release_path(path);