linux/drivers/hwtracing/coresight/coresight.c
Mathieu Poirier 01081f5ab9 coresight: moving to new "hwtracing" directory
Keeping drivers related to HW tracing on ARM, i.e coresight,
under "drivers/coresight" doesn't make sense when other
architectures start rolling out technologies of the same
nature.

As such creating a new "drivers/hwtracing" directory where all
drivers of the same kind can reside, reducing namespace
pollution under "drivers/".

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:17:04 +02:00

721 lines
16 KiB
C

/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/coresight.h>
#include <linux/of_platform.h>
#include <linux/delay.h>
#include "coresight-priv.h"
static DEFINE_MUTEX(coresight_mutex);
static int coresight_id_match(struct device *dev, void *data)
{
int trace_id, i_trace_id;
struct coresight_device *csdev, *i_csdev;
csdev = data;
i_csdev = to_coresight_device(dev);
/*
* No need to care about oneself and components that are not
* sources or not enabled
*/
if (i_csdev == csdev || !i_csdev->enable ||
i_csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
return 0;
/* Get the source ID for both compoment */
trace_id = source_ops(csdev)->trace_id(csdev);
i_trace_id = source_ops(i_csdev)->trace_id(i_csdev);
/* All you need is one */
if (trace_id == i_trace_id)
return 1;
return 0;
}
static int coresight_source_is_unique(struct coresight_device *csdev)
{
int trace_id = source_ops(csdev)->trace_id(csdev);
/* this shouldn't happen */
if (trace_id < 0)
return 0;
return !bus_for_each_dev(&coresight_bustype, NULL,
csdev, coresight_id_match);
}
static int coresight_find_link_inport(struct coresight_device *csdev)
{
int i;
struct coresight_device *parent;
struct coresight_connection *conn;
parent = container_of(csdev->path_link.next,
struct coresight_device, path_link);
for (i = 0; i < parent->nr_outport; i++) {
conn = &parent->conns[i];
if (conn->child_dev == csdev)
return conn->child_port;
}
dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n",
dev_name(&parent->dev), dev_name(&csdev->dev));
return 0;
}
static int coresight_find_link_outport(struct coresight_device *csdev)
{
int i;
struct coresight_device *child;
struct coresight_connection *conn;
child = container_of(csdev->path_link.prev,
struct coresight_device, path_link);
for (i = 0; i < csdev->nr_outport; i++) {
conn = &csdev->conns[i];
if (conn->child_dev == child)
return conn->outport;
}
dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n",
dev_name(&csdev->dev), dev_name(&child->dev));
return 0;
}
static int coresight_enable_sink(struct coresight_device *csdev)
{
int ret;
if (!csdev->enable) {
if (sink_ops(csdev)->enable) {
ret = sink_ops(csdev)->enable(csdev);
if (ret)
return ret;
}
csdev->enable = true;
}
atomic_inc(csdev->refcnt);
return 0;
}
static void coresight_disable_sink(struct coresight_device *csdev)
{
if (atomic_dec_return(csdev->refcnt) == 0) {
if (sink_ops(csdev)->disable) {
sink_ops(csdev)->disable(csdev);
csdev->enable = false;
}
}
}
static int coresight_enable_link(struct coresight_device *csdev)
{
int ret;
int link_subtype;
int refport, inport, outport;
inport = coresight_find_link_inport(csdev);
outport = coresight_find_link_outport(csdev);
link_subtype = csdev->subtype.link_subtype;
if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
refport = inport;
else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
refport = outport;
else
refport = 0;
if (atomic_inc_return(&csdev->refcnt[refport]) == 1) {
if (link_ops(csdev)->enable) {
ret = link_ops(csdev)->enable(csdev, inport, outport);
if (ret)
return ret;
}
}
csdev->enable = true;
return 0;
}
static void coresight_disable_link(struct coresight_device *csdev)
{
int i, nr_conns;
int link_subtype;
int refport, inport, outport;
inport = coresight_find_link_inport(csdev);
outport = coresight_find_link_outport(csdev);
link_subtype = csdev->subtype.link_subtype;
if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
refport = inport;
nr_conns = csdev->nr_inport;
} else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
refport = outport;
nr_conns = csdev->nr_outport;
} else {
refport = 0;
nr_conns = 1;
}
if (atomic_dec_return(&csdev->refcnt[refport]) == 0) {
if (link_ops(csdev)->disable)
link_ops(csdev)->disable(csdev, inport, outport);
}
for (i = 0; i < nr_conns; i++)
if (atomic_read(&csdev->refcnt[i]) != 0)
return;
csdev->enable = false;
}
static int coresight_enable_source(struct coresight_device *csdev)
{
int ret;
if (!coresight_source_is_unique(csdev)) {
dev_warn(&csdev->dev, "traceID %d not unique\n",
source_ops(csdev)->trace_id(csdev));
return -EINVAL;
}
if (!csdev->enable) {
if (source_ops(csdev)->enable) {
ret = source_ops(csdev)->enable(csdev);
if (ret)
return ret;
}
csdev->enable = true;
}
atomic_inc(csdev->refcnt);
return 0;
}
static void coresight_disable_source(struct coresight_device *csdev)
{
if (atomic_dec_return(csdev->refcnt) == 0) {
if (source_ops(csdev)->disable) {
source_ops(csdev)->disable(csdev);
csdev->enable = false;
}
}
}
static int coresight_enable_path(struct list_head *path)
{
int ret = 0;
struct coresight_device *cd;
list_for_each_entry(cd, path, path_link) {
if (cd == list_first_entry(path, struct coresight_device,
path_link)) {
ret = coresight_enable_sink(cd);
} else if (list_is_last(&cd->path_link, path)) {
/*
* Don't enable the source just yet - this needs to
* happen at the very end when all links and sink
* along the path have been configured properly.
*/
;
} else {
ret = coresight_enable_link(cd);
}
if (ret)
goto err;
}
return 0;
err:
list_for_each_entry_continue_reverse(cd, path, path_link) {
if (cd == list_first_entry(path, struct coresight_device,
path_link)) {
coresight_disable_sink(cd);
} else if (list_is_last(&cd->path_link, path)) {
;
} else {
coresight_disable_link(cd);
}
}
return ret;
}
static int coresight_disable_path(struct list_head *path)
{
struct coresight_device *cd;
list_for_each_entry_reverse(cd, path, path_link) {
if (cd == list_first_entry(path, struct coresight_device,
path_link)) {
coresight_disable_sink(cd);
} else if (list_is_last(&cd->path_link, path)) {
/*
* The source has already been stopped, no need
* to do it again here.
*/
;
} else {
coresight_disable_link(cd);
}
}
return 0;
}
static int coresight_build_paths(struct coresight_device *csdev,
struct list_head *path,
bool enable)
{
int i, ret = -EINVAL;
struct coresight_connection *conn;
list_add(&csdev->path_link, path);
if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
csdev->activated) {
if (enable)
ret = coresight_enable_path(path);
else
ret = coresight_disable_path(path);
} else {
for (i = 0; i < csdev->nr_outport; i++) {
conn = &csdev->conns[i];
if (coresight_build_paths(conn->child_dev,
path, enable) == 0)
ret = 0;
}
}
if (list_first_entry(path, struct coresight_device, path_link) != csdev)
dev_err(&csdev->dev, "wrong device in %s\n", __func__);
list_del(&csdev->path_link);
return ret;
}
int coresight_enable(struct coresight_device *csdev)
{
int ret = 0;
LIST_HEAD(path);
mutex_lock(&coresight_mutex);
if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
ret = -EINVAL;
dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
goto out;
}
if (csdev->enable)
goto out;
if (coresight_build_paths(csdev, &path, true)) {
dev_err(&csdev->dev, "building path(s) failed\n");
goto out;
}
if (coresight_enable_source(csdev))
dev_err(&csdev->dev, "source enable failed\n");
out:
mutex_unlock(&coresight_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(coresight_enable);
void coresight_disable(struct coresight_device *csdev)
{
LIST_HEAD(path);
mutex_lock(&coresight_mutex);
if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
goto out;
}
if (!csdev->enable)
goto out;
coresight_disable_source(csdev);
if (coresight_build_paths(csdev, &path, false))
dev_err(&csdev->dev, "releasing path(s) failed\n");
out:
mutex_unlock(&coresight_mutex);
}
EXPORT_SYMBOL_GPL(coresight_disable);
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", (unsigned)csdev->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;
if (val)
csdev->activated = true;
else
csdev->activated = false;
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);
return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->enable);
}
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(csdev);
if (ret)
return ret;
} else {
coresight_disable(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);
static struct device_type coresight_dev_type[] = {
{
.name = "none",
},
{
.name = "sink",
.groups = coresight_sink_groups,
},
{
.name = "link",
},
{
.name = "linksink",
.groups = coresight_sink_groups,
},
{
.name = "source",
.groups = coresight_source_groups,
},
};
static void coresight_device_release(struct device *dev)
{
struct coresight_device *csdev = to_coresight_device(dev);
kfree(csdev);
}
static int coresight_orphan_match(struct device *dev, void *data)
{
int i;
bool still_orphan = false;
struct coresight_device *csdev, *i_csdev;
struct coresight_connection *conn;
csdev = data;
i_csdev = to_coresight_device(dev);
/* No need to check oneself */
if (csdev == i_csdev)
return 0;
/* Move on to another component if no connection is orphan */
if (!i_csdev->orphan)
return 0;
/*
* Circle throuch all the connection of that component. If we find
* an orphan connection whose name matches @csdev, link it.
*/
for (i = 0; i < i_csdev->nr_outport; i++) {
conn = &i_csdev->conns[i];
/* We have found at least one orphan connection */
if (conn->child_dev == NULL) {
/* Does it match this newly added device? */
if (!strcmp(dev_name(&csdev->dev), conn->child_name)) {
conn->child_dev = csdev;
} else {
/* This component still has an orphan */
still_orphan = true;
}
}
}
i_csdev->orphan = still_orphan;
/*
* Returning '0' ensures that all known component on the
* bus will be checked.
*/
return 0;
}
static void coresight_fixup_orphan_conns(struct coresight_device *csdev)
{
/*
* No need to check for a return value as orphan connection(s)
* are hooked-up with each newly added component.
*/
bus_for_each_dev(&coresight_bustype, NULL,
csdev, coresight_orphan_match);
}
static int coresight_name_match(struct device *dev, void *data)
{
char *to_match;
struct coresight_device *i_csdev;
to_match = data;
i_csdev = to_coresight_device(dev);
if (!strcmp(to_match, dev_name(&i_csdev->dev)))
return 1;
return 0;
}
static void coresight_fixup_device_conns(struct coresight_device *csdev)
{
int i;
struct device *dev = NULL;
struct coresight_connection *conn;
for (i = 0; i < csdev->nr_outport; i++) {
conn = &csdev->conns[i];
dev = bus_find_device(&coresight_bustype, NULL,
(void *)conn->child_name,
coresight_name_match);
if (dev) {
conn->child_dev = to_coresight_device(dev);
} else {
csdev->orphan = true;
conn->child_dev = NULL;
}
}
}
/**
* coresight_timeout - loop until a bit has changed to a specific state.
* @addr: base address of the area of interest.
* @offset: address of a register, starting from @addr.
* @position: the position of the bit of interest.
* @value: the value the bit should have.
*
* Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
* TIMEOUT_US has elapsed, which ever happens first.
*/
int coresight_timeout(void __iomem *addr, u32 offset, int position, int value)
{
int i;
u32 val;
for (i = TIMEOUT_US; i > 0; i--) {
val = __raw_readl(addr + offset);
/* waiting on the bit to go from 0 to 1 */
if (value) {
if (val & BIT(position))
return 0;
/* waiting on the bit to go from 1 to 0 */
} else {
if (!(val & BIT(position)))
return 0;
}
/*
* Delay is arbitrary - the specification doesn't say how long
* we are expected to wait. Extra check required to make sure
* we don't wait needlessly on the last iteration.
*/
if (i - 1)
udelay(1);
}
return -EAGAIN;
}
struct bus_type coresight_bustype = {
.name = "coresight",
};
static int __init coresight_init(void)
{
return bus_register(&coresight_bustype);
}
postcore_initcall(coresight_init);
struct coresight_device *coresight_register(struct coresight_desc *desc)
{
int i;
int ret;
int link_subtype;
int nr_refcnts = 1;
atomic_t *refcnts = NULL;
struct coresight_device *csdev;
struct coresight_connection *conns;
csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
if (!csdev) {
ret = -ENOMEM;
goto err_kzalloc_csdev;
}
if (desc->type == CORESIGHT_DEV_TYPE_LINK ||
desc->type == CORESIGHT_DEV_TYPE_LINKSINK) {
link_subtype = desc->subtype.link_subtype;
if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
nr_refcnts = desc->pdata->nr_inport;
else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
nr_refcnts = desc->pdata->nr_outport;
}
refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
if (!refcnts) {
ret = -ENOMEM;
goto err_kzalloc_refcnts;
}
csdev->refcnt = refcnts;
csdev->nr_inport = desc->pdata->nr_inport;
csdev->nr_outport = desc->pdata->nr_outport;
conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
if (!conns) {
ret = -ENOMEM;
goto err_kzalloc_conns;
}
for (i = 0; i < csdev->nr_outport; i++) {
conns[i].outport = desc->pdata->outports[i];
conns[i].child_name = desc->pdata->child_names[i];
conns[i].child_port = desc->pdata->child_ports[i];
}
csdev->conns = conns;
csdev->type = desc->type;
csdev->subtype = desc->subtype;
csdev->ops = desc->ops;
csdev->orphan = false;
csdev->dev.type = &coresight_dev_type[desc->type];
csdev->dev.groups = desc->groups;
csdev->dev.parent = desc->dev;
csdev->dev.release = coresight_device_release;
csdev->dev.bus = &coresight_bustype;
dev_set_name(&csdev->dev, "%s", desc->pdata->name);
ret = device_register(&csdev->dev);
if (ret)
goto err_device_register;
mutex_lock(&coresight_mutex);
coresight_fixup_device_conns(csdev);
coresight_fixup_orphan_conns(csdev);
mutex_unlock(&coresight_mutex);
return csdev;
err_device_register:
kfree(conns);
err_kzalloc_conns:
kfree(refcnts);
err_kzalloc_refcnts:
kfree(csdev);
err_kzalloc_csdev:
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(coresight_register);
void coresight_unregister(struct coresight_device *csdev)
{
mutex_lock(&coresight_mutex);
kfree(csdev->conns);
device_unregister(&csdev->dev);
mutex_unlock(&coresight_mutex);
}
EXPORT_SYMBOL_GPL(coresight_unregister);
MODULE_LICENSE("GPL v2");