// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2019, Linaro Limited, All rights reserved.
* Author: Mike Leach <[email protected]>
*/
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include "coresight-priv.h"
/*
* Use IDR to map the hash of the source's device name
* to the pointer of path for the source. The idr is for
* the sources which aren't associated with CPU.
*/
static DEFINE_IDR(path_idr);
/*
* When operating Coresight drivers from the sysFS interface, only a single
* path can exist from a tracer (associated to a CPU) to a sink.
*/
static DEFINE_PER_CPU(struct list_head *, tracer_path);
ssize_t coresight_simple_show_pair(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
struct cs_pair_attribute *cs_attr = container_of(attr, struct cs_pair_attribute, attr);
u64 val;
pm_runtime_get_sync(_dev->parent);
val = csdev_access_relaxed_read_pair(&csdev->access, cs_attr->lo_off, cs_attr->hi_off);
pm_runtime_put_sync(_dev->parent);
return sysfs_emit(buf, "0x%llx\n", val);
}
EXPORT_SYMBOL_GPL(coresight_simple_show_pair);
ssize_t coresight_simple_show32(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct coresight_device *csdev = container_of(_dev, struct coresight_device, dev);
struct cs_off_attribute *cs_attr = container_of(attr, struct cs_off_attribute, attr);
u64 val;
pm_runtime_get_sync(_dev->parent);
val = csdev_access_relaxed_read32(&csdev->access, cs_attr->off);
pm_runtime_put_sync(_dev->parent);
return sysfs_emit(buf, "0x%llx\n", val);
}
EXPORT_SYMBOL_GPL(coresight_simple_show32);
static int coresight_enable_source_sysfs(struct coresight_device *csdev,
enum cs_mode mode, void *data)
{
int ret;
/*
* Comparison with CS_MODE_SYSFS works without taking any device
* specific spinlock because the truthyness of that comparison can only
* change with coresight_mutex held, which we already have here.
*/
lockdep_assert_held(&coresight_mutex);
if (coresight_get_mode(csdev) != CS_MODE_SYSFS) {
ret = source_ops(csdev)->enable(csdev, data, mode);
if (ret)
return ret;
}
csdev->refcnt++;
return 0;
}
/**
* coresight_disable_source_sysfs - Drop the reference count by 1 and disable
* the device if there are no users left.
*
* @csdev: The coresight device to disable
* @data: Opaque data to pass on to the disable function of the source device.
* For example in perf mode this is a pointer to the struct perf_event.
*
* Returns true if the device has been disabled.
*/
static bool coresight_disable_source_sysfs(struct coresight_device *csdev,
void *data)
{
lockdep_assert_held(&coresight_mutex);
if (coresight_get_mode(csdev) != CS_MODE_SYSFS)
return false;
csdev->refcnt--;
if (csdev->refcnt == 0) {
coresight_disable_source(csdev, data);
return true;
}
return false;
}
/**
* coresight_find_activated_sysfs_sink - returns the first sink activated via
* sysfs using connection based search starting from the source reference.
*
* @csdev: Coresight source device reference
*/
static struct coresight_device *
coresight_find_activated_sysfs_sink(struct coresight_device *csdev)
{
int i;
struct coresight_device *sink = NULL;
if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
csdev->sysfs_sink_activated)
return csdev;
/*
* Recursively explore each port found on this element.
*/
for (i = 0; i < csdev->pdata->nr_outconns; i++) {
struct coresight_device *child_dev;
child_dev = csdev->pdata->out_conns[i]->dest_dev;
if (child_dev)
sink = coresight_find_activated_sysfs_sink(child_dev);
if (sink)
return sink;
}
return NULL;
}
/** coresight_validate_source - make sure a source has the right credentials to
* be used via sysfs.
* @csdev: the device structure for a source.
* @function: the function this was called from.
*
* Assumes the coresight_mutex is held.
*/
static int coresight_validate_source_sysfs(struct coresight_device *csdev,
const char *function)
{
u32 type, subtype;
type = csdev->type;
subtype = csdev->subtype.source_subtype;
if (type != CORESIGHT_DEV_TYPE_SOURCE) {
dev_err(&csdev->dev, "wrong device type in %s\n", function);
return -EINVAL;
}
if (subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_PROC &&
subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE &&
subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM &&
subtype != CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS) {
dev_err(&csdev->dev, "wrong device subtype in %s\n", function);
return -EINVAL;
}
return 0;
}
int coresight_enable_sysfs(struct coresight_device *csdev)
{
int cpu, ret = 0;
struct coresight_device *sink;
struct list_head *path;
enum coresight_dev_subtype_source subtype;
u32 hash;
subtype = csdev->subtype.source_subtype;
mutex_lock(&coresight_mutex);
ret = coresight_validate_source_sysfs(csdev, __func__);
if (ret)
goto out;
/*
* mode == SYSFS implies that it's already enabled. Don't look at the
* refcount to determine this because we don't claim the source until
* coresight_enable_source() so can still race with Perf mode which
* doesn't hold coresight_mutex.
*/
if (coresight_get_mode(csdev) == CS_MODE_SYSFS) {
/*
* There could be multiple applications driving the software
* source. So keep the refcount for each such user when the
* source is already enabled.
*/
if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
csdev->refcnt++;
goto out;
}
sink = coresight_find_activated_sysfs_sink(csdev);
if (!sink) {
ret = -EINVAL;
goto out;
}
path = coresight_build_path(csdev, sink);
if (IS_ERR(path)) {
pr_err("building path(s) failed\n");
ret = PTR_ERR(path);
goto out;
}
ret = coresight_enable_path(path, CS_MODE_SYSFS, NULL);
if (ret)
goto err_path;
ret = coresight_enable_source_sysfs(csdev, CS_MODE_SYSFS, NULL);
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:
case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM:
case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
/*
* Use the hash of source's device name as ID
* and map the ID to the pointer of the path.
*/
hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));
ret = idr_alloc_u32(&path_idr, path, &hash, hash, GFP_KERNEL);
if (ret)
goto err_source;
break;
default:
/* We can't be here */
break;
}
out:
mutex_unlock(&coresight_mutex);
return ret;
err_source:
coresight_disable_path(path);
err_path:
coresight_release_path(path);
goto out;
}
EXPORT_SYMBOL_GPL(coresight_enable_sysfs);
void coresight_disable_sysfs(struct coresight_device *csdev)
{
int cpu, ret;
struct list_head *path = NULL;
u32 hash;
mutex_lock(&coresight_mutex);
ret = coresight_validate_source_sysfs(csdev, __func__);
if (ret)
goto out;
if (!coresight_disable_source_sysfs(csdev, NULL))
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:
case CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM:
case CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS:
hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));
/* Find the path by the hash. */
path = idr_find(&path_idr, hash);
if (path == NULL) {
pr_err("Path is not found for %s\n", dev_name(&csdev->dev));
goto out;
}
idr_remove(&path_idr, hash);
break;
default:
/* We can't be here */
break;
}
coresight_disable_path(path);
coresight_release_path(path);
out:
mutex_unlock(&coresight_mutex);
}
EXPORT_SYMBOL_GPL(coresight_disable_sysfs);
static ssize_t enable_sink_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct coresight_device *csdev = to_coresight_device(dev);
return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->sysfs_sink_activated);
}
static ssize_t enable_sink_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
int ret;
unsigned long val;
struct coresight_device *csdev = to_coresight_device(dev);
ret = kstrtoul(buf, 10, &val);
if (ret)
return ret;
csdev->sysfs_sink_activated = !!val;
return size;
}
static DEVICE_ATTR_RW(enable_sink);
static ssize_t enable_source_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct coresight_device *csdev = to_coresight_device(dev);
guard(mutex)(&coresight_mutex);
return scnprintf(buf, PAGE_SIZE, "%u\n",
coresight_get_mode(csdev) == CS_MODE_SYSFS);
}
static ssize_t enable_source_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
int ret = 0;
unsigned long val;
struct coresight_device *csdev = to_coresight_device(dev);
ret = kstrtoul(buf, 10, &val);
if (ret)
return ret;
if (val) {
ret = coresight_enable_sysfs(csdev);
if (ret)
return ret;
} else {
coresight_disable_sysfs(csdev);
}
return size;
}
static DEVICE_ATTR_RW(enable_source);
static struct attribute *coresight_sink_attrs[] = {
&dev_attr_enable_sink.attr,
NULL,
};
ATTRIBUTE_GROUPS(coresight_sink);
static struct attribute *coresight_source_attrs[] = {
&dev_attr_enable_source.attr,
NULL,
};
ATTRIBUTE_GROUPS(coresight_source);
const struct device_type coresight_dev_type[] = {
[CORESIGHT_DEV_TYPE_SINK] = {
.name = "sink",
.groups = coresight_sink_groups,
},
[CORESIGHT_DEV_TYPE_LINK] = {
.name = "link",
},
[CORESIGHT_DEV_TYPE_LINKSINK] = {
.name = "linksink",
.groups = coresight_sink_groups,
},
[CORESIGHT_DEV_TYPE_SOURCE] = {
.name = "source",
.groups = coresight_source_groups,
},
[CORESIGHT_DEV_TYPE_HELPER] = {
.name = "helper",
}
};
/* Ensure the enum matches the names and groups */
static_assert(ARRAY_SIZE(coresight_dev_type) == CORESIGHT_DEV_TYPE_MAX);
/*
* Connections group - links attribute.
* Count of created links between coresight components in the group.
*/
static ssize_t nr_links_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct coresight_device *csdev = to_coresight_device(dev);
return sprintf(buf, "%d\n", csdev->nr_links);
}
static DEVICE_ATTR_RO(nr_links);
static struct attribute *coresight_conns_attrs[] = {
&dev_attr_nr_links.attr,
NULL,
};
static struct attribute_group coresight_conns_group = {
.attrs = coresight_conns_attrs,
.name = "connections",
};
/*
* Create connections group for CoreSight devices.
* This group will then be used to collate the sysfs links between
* devices.
*/
int coresight_create_conns_sysfs_group(struct coresight_device *csdev)
{
int ret = 0;
if (!csdev)
return -EINVAL;
ret = sysfs_create_group(&csdev->dev.kobj, &coresight_conns_group);
if (ret)
return ret;
csdev->has_conns_grp = true;
return ret;
}
void coresight_remove_conns_sysfs_group(struct coresight_device *csdev)
{
if (!csdev)
return;
if (csdev->has_conns_grp) {
sysfs_remove_group(&csdev->dev.kobj, &coresight_conns_group);
csdev->has_conns_grp = false;
}
}
int coresight_add_sysfs_link(struct coresight_sysfs_link *info)
{
int ret = 0;
if (!info)
return -EINVAL;
if (!info->orig || !info->target ||
!info->orig_name || !info->target_name)
return -EINVAL;
if (!info->orig->has_conns_grp || !info->target->has_conns_grp)
return -EINVAL;
/* first link orig->target */
ret = sysfs_add_link_to_group(&info->orig->dev.kobj,
coresight_conns_group.name,
&info->target->dev.kobj,
info->orig_name);
if (ret)
return ret;
/* second link target->orig */
ret = sysfs_add_link_to_group(&info->target->dev.kobj,
coresight_conns_group.name,
&info->orig->dev.kobj,
info->target_name);
/* error in second link - remove first - otherwise inc counts */
if (ret) {
sysfs_remove_link_from_group(&info->orig->dev.kobj,
coresight_conns_group.name,
info->orig_name);
} else {
info->orig->nr_links++;
info->target->nr_links++;
}
return ret;
}
EXPORT_SYMBOL_GPL(coresight_add_sysfs_link);
void coresight_remove_sysfs_link(struct coresight_sysfs_link *info)
{
if (!info)
return;
if (!info->orig || !info->target ||
!info->orig_name || !info->target_name)
return;
sysfs_remove_link_from_group(&info->orig->dev.kobj,
coresight_conns_group.name,
info->orig_name);
sysfs_remove_link_from_group(&info->target->dev.kobj,
coresight_conns_group.name,
info->target_name);
info->orig->nr_links--;
info->target->nr_links--;
}
EXPORT_SYMBOL_GPL(coresight_remove_sysfs_link);
/*
* coresight_make_links: Make a link for a connection from a @orig
* device to @target, represented by @conn.
*
* e.g, for devOrig[output_X] -> devTarget[input_Y] is represented
* as two symbolic links :
*
* /sys/.../devOrig/out:X -> /sys/.../devTarget/
* /sys/.../devTarget/in:Y -> /sys/.../devOrig/
*
* The link names are allocated for a device where it appears. i.e, the
* "out" link on the master and "in" link on the slave device.
* The link info is stored in the connection record for avoiding
* the reconstruction of names for removal.
*/
int coresight_make_links(struct coresight_device *orig,
struct coresight_connection *conn,
struct coresight_device *target)
{
int ret = -ENOMEM;
char *outs = NULL, *ins = NULL;
struct coresight_sysfs_link *link = NULL;
/* Helper devices aren't shown in sysfs */
if (conn->dest_port == -1 && conn->src_port == -1)
return 0;
do {
outs = devm_kasprintf(&orig->dev, GFP_KERNEL,
"out:%d", conn->src_port);
if (!outs)
break;
ins = devm_kasprintf(&target->dev, GFP_KERNEL,
"in:%d", conn->dest_port);
if (!ins)
break;
link = devm_kzalloc(&orig->dev,
sizeof(struct coresight_sysfs_link),
GFP_KERNEL);
if (!link)
break;
link->orig = orig;
link->target = target;
link->orig_name = outs;
link->target_name = ins;
ret = coresight_add_sysfs_link(link);
if (ret)
break;
conn->link = link;
return 0;
} while (0);
return ret;
}
/*
* coresight_remove_links: Remove the sysfs links for a given connection @conn,
* from @orig device to @target device. See coresight_make_links() for more
* details.
*/
void coresight_remove_links(struct coresight_device *orig,
struct coresight_connection *conn)
{
if (!orig || !conn->link)
return;
coresight_remove_sysfs_link(conn->link);
devm_kfree(&conn->dest_dev->dev, conn->link->target_name);
devm_kfree(&orig->dev, conn->link->orig_name);
devm_kfree(&orig->dev, conn->link);
conn->link = NULL;
}
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