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/*
* Copyright (c) 2012, The Linux Foundation. All rights reserved.
*/
#include <linux/kernel.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 <linux/pm_runtime.h>
#include "coresight-priv.h"
static DEFINE_MUTEX(coresight_mutex);
/**
* struct coresight_node - elements of a path, from source to sink
* @csdev: Address of an element.
* @link: hook to the list.
*/
struct coresight_node {
struct coresight_device *csdev;
struct list_head link;
};
/*
* 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);
/*
* 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;
/*
* When losing synchronisation a new barrier packet needs to be inserted at the
* beginning of the data collected in a buffer. That way the decoder knows that
* it needs to look for another sync sequence.
*/
const u32 barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};
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,
struct coresight_device *parent)
{
int i;
struct coresight_connection *conn;
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 -ENODEV;
}
static int coresight_find_link_outport(struct coresight_device *csdev,
struct coresight_device *child)
{
int i;
struct coresight_connection *conn;
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 -ENODEV;
}
static inline u32 coresight_read_claim_tags(void __iomem *base)
{
return readl_relaxed(base + CORESIGHT_CLAIMCLR);
}
static inline bool coresight_is_claimed_self_hosted(void __iomem *base)
{
return coresight_read_claim_tags(base) == CORESIGHT_CLAIM_SELF_HOSTED;
}
static inline bool coresight_is_claimed_any(void __iomem *base)
{
return coresight_read_claim_tags(base) != 0;
}
static inline void coresight_set_claim_tags(void __iomem *base)
{
writel_relaxed(CORESIGHT_CLAIM_SELF_HOSTED, base + CORESIGHT_CLAIMSET);
isb();
}
static inline void coresight_clear_claim_tags(void __iomem *base)
{
writel_relaxed(CORESIGHT_CLAIM_SELF_HOSTED, base + CORESIGHT_CLAIMCLR);
isb();
}
/*
* coresight_claim_device_unlocked : Claim the device for self-hosted usage
* to prevent an external tool from touching this device. As per PSCI
* standards, section "Preserving the execution context" => "Debug and Trace
* save and Restore", DBGCLAIM[1] is reserved for Self-hosted debug/trace and
* DBGCLAIM[0] is reserved for external tools.
*
* Called with CS_UNLOCKed for the component.
* Returns : 0 on success
*/
int coresight_claim_device_unlocked(void __iomem *base)
{
if (coresight_is_claimed_any(base))
return -EBUSY;
coresight_set_claim_tags(base);
if (coresight_is_claimed_self_hosted(base))
return 0;
/* There was a race setting the tags, clean up and fail */
coresight_clear_claim_tags(base);
return -EBUSY;
}
int coresight_claim_device(void __iomem *base)
{
int rc;
CS_UNLOCK(base);
rc = coresight_claim_device_unlocked(base);
CS_LOCK(base);
return rc;
}
/*
* coresight_disclaim_device_unlocked : Clear the claim tags for the device.
* Called with CS_UNLOCKed for the component.
*/
void coresight_disclaim_device_unlocked(void __iomem *base)
{
if (coresight_is_claimed_self_hosted(base))
coresight_clear_claim_tags(base);
else
/*
* The external agent may have not honoured our claim
* and has manipulated it. Or something else has seriously
* gone wrong in our driver.
*/
WARN_ON_ONCE(1);
}
void coresight_disclaim_device(void __iomem *base)
{
CS_UNLOCK(base);
coresight_disclaim_device_unlocked(base);
CS_LOCK(base);
}
static int coresight_enable_sink(struct coresight_device *csdev,
u32 mode, void *data)
{
int ret;
/*
* We need to make sure the "new" session is compatible with the
* existing "mode" of operation.
*/
if (sink_ops(csdev)->enable) {
ret = sink_ops(csdev)->enable(csdev, mode, data);
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,
struct coresight_device *parent,
struct coresight_device *child)
{
int ret;
int link_subtype;
int refport, inport, outport;
if (!parent || !child)
return -EINVAL;
inport = coresight_find_link_inport(csdev, parent);
outport = coresight_find_link_outport(csdev, child);
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 (refport < 0)
return refport;
if (atomic_inc_return(&csdev->refcnt[refport]) == 1) {
if (link_ops(csdev)->enable) {
ret = link_ops(csdev)->enable(csdev, inport, outport);
if (ret) {
atomic_dec(&csdev->refcnt[refport]);
return ret;
}
}
}
csdev->enable = true;
return 0;
}
static void coresight_disable_link(struct coresight_device *csdev,
struct coresight_device *parent,
struct coresight_device *child)
{
int i, nr_conns;
int link_subtype;
int refport, inport, outport;
if (!parent || !child)
return;
inport = coresight_find_link_inport(csdev, parent);
outport = coresight_find_link_outport(csdev, child);
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, u32 mode)
{
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, NULL, mode);
if (ret)
return ret;
}
csdev->enable = true;
}
atomic_inc(csdev->refcnt);
return 0;
}
/**
* coresight_disable_source - Drop the reference count by 1 and disable
* the device if there are no users left.
*
* @csdev - The coresight device to disable
*
* Returns true if the device has been disabled.
*/
static bool coresight_disable_source(struct coresight_device *csdev)
{
if (atomic_dec_return(csdev->refcnt) == 0) {
if (source_ops(csdev)->disable)
source_ops(csdev)->disable(csdev, NULL);
csdev->enable = false;
}
return !csdev->enable;
}
/*
* coresight_disable_path_from : Disable components in the given path beyond
* @nd in the list. If @nd is NULL, all the components, except the SOURCE are
* disabled.
*/
static void coresight_disable_path_from(struct list_head *path,
struct coresight_node *nd)
{
u32 type;
struct coresight_device *csdev, *parent, *child;
if (!nd)
nd = list_first_entry(path, struct coresight_node, link);
list_for_each_entry_continue(nd, path, link) {
csdev = nd->csdev;
type = csdev->type;
/*
* ETF devices are tricky... They can be a link or a sink,
* depending on how they are configured. If an ETF has been
* "activated" it will be configured as a sink, otherwise
* go ahead with the link configuration.
*/
if (type == CORESIGHT_DEV_TYPE_LINKSINK)
type = (csdev == coresight_get_sink(path)) ?
CORESIGHT_DEV_TYPE_SINK :
CORESIGHT_DEV_TYPE_LINK;
switch (type) {
case CORESIGHT_DEV_TYPE_SINK:
coresight_disable_sink(csdev);
break;
case CORESIGHT_DEV_TYPE_SOURCE:
/*
* We skip the first node in the path assuming that it
* is the source. So we don't expect a source device in
* the middle of a path.
*/
WARN_ON(1);
break;
case CORESIGHT_DEV_TYPE_LINK:
parent = list_prev_entry(nd, link)->csdev;
child = list_next_entry(nd, link)->csdev;
coresight_disable_link(csdev, parent, child);
break;
default:
break;
}
}
}
void coresight_disable_path(struct list_head *path)
{
coresight_disable_path_from(path, NULL);
}
int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data)
{
int ret = 0;
u32 type;
struct coresight_node *nd;
struct coresight_device *csdev, *parent, *child;
list_for_each_entry_reverse(nd, path, link) {
csdev = nd->csdev;
type = csdev->type;
/*
* ETF devices are tricky... They can be a link or a sink,
* depending on how they are configured. If an ETF has been
* "activated" it will be configured as a sink, otherwise
* go ahead with the link configuration.
*/
if (type == CORESIGHT_DEV_TYPE_LINKSINK)
type = (csdev == coresight_get_sink(path)) ?
CORESIGHT_DEV_TYPE_SINK :
CORESIGHT_DEV_TYPE_LINK;
switch (type) {
case CORESIGHT_DEV_TYPE_SINK:
ret = coresight_enable_sink(csdev, mode, sink_data);
/*
* Sink is the first component turned on. If we
* failed to enable the sink, there are no components
* that need disabling. Disabling the path here
* would mean we could disrupt an existing session.
*/
if (ret)
goto out;
break;
case CORESIGHT_DEV_TYPE_SOURCE:
/* sources are enabled from either sysFS or Perf */
break;
case CORESIGHT_DEV_TYPE_LINK:
parent = list_prev_entry(nd, link)->csdev;
child = list_next_entry(nd, link)->csdev;
ret = coresight_enable_link(csdev, parent, child);
if (ret)
goto err;
break;
default:
goto err;
}
}
out:
return ret;
err:
coresight_disable_path_from(path, nd);
goto out;
}
struct coresight_device *coresight_get_sink(struct list_head *path)
{
struct coresight_device *csdev;
if (!path)
return NULL;
csdev = list_last_entry(path, struct coresight_node, link)->csdev;
if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
return NULL;
return csdev;
}
static int coresight_enabled_sink(struct device *dev, void *data)
{
bool *reset = data;
struct coresight_device *csdev = to_coresight_device(dev);
if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
csdev->activated) {
/*
* Now that we have a handle on the sink for this session,
* disable the sysFS "enable_sink" flag so that possible
* concurrent perf session that wish to use another sink don't
* trip on it. Doing so has no ramification for the current
* session.
*/
if (*reset)
csdev->activated = false;
return 1;
}
return 0;
}
/**
* coresight_get_enabled_sink - returns the first enabled sink found on the bus
* @deactivate: Whether the 'enable_sink' flag should be reset
*
* When operated from perf the deactivate parameter should be set to 'true'.
* That way the "enabled_sink" flag of the sink that was selected can be reset,
* allowing for other concurrent perf sessions to choose a different sink.
*
* When operated from sysFS users have full control and as such the deactivate
* parameter should be set to 'false', hence mandating users to explicitly
* clear the flag.
*/
struct coresight_device *coresight_get_enabled_sink(bool deactivate)
{
struct device *dev = NULL;
dev = bus_find_device(&coresight_bustype, NULL, &deactivate,
coresight_enabled_sink);
return dev ? to_coresight_device(dev) : NULL;
}
/*
* coresight_grab_device - Power up this device and any of the helper
* devices connected to it for trace operation. Since the helper devices
* don't appear on the trace path, they should be handled along with the
* the master device.
*/
static void coresight_grab_device(struct coresight_device *csdev)
{
int i;
for (i = 0; i < csdev->nr_outport; i++) {
struct coresight_device *child = csdev->conns[i].child_dev;
if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
pm_runtime_get_sync(child->dev.parent);
}
pm_runtime_get_sync(csdev->dev.parent);
}
/*
* coresight_drop_device - Release this device and any of the helper
* devices connected to it.
*/
static void coresight_drop_device(struct coresight_device *csdev)
{
int i;
pm_runtime_put(csdev->dev.parent);
for (i = 0; i < csdev->nr_outport; i++) {
struct coresight_device *child = csdev->conns[i].child_dev;
if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
pm_runtime_put(child->dev.parent);
}
}
/**
* _coresight_build_path - recursively build a path from a @csdev to a sink.
* @csdev: The device to start from.
* @path: The list to add devices to.
*
* The tree of Coresight device is traversed until an activated sink is
* found. From there the sink is added to the list along with all the
* devices that led to that point - the end result is a list from source
* to sink. In that list the source is the first device and the sink the
* last one.
*/
static int _coresight_build_path(struct coresight_device *csdev,
struct coresight_device *sink,
struct list_head *path)
{
int i;
bool found = false;
struct coresight_node *node;
/* An activated sink has been found. Enqueue the element */
if (csdev == sink)
goto out;
/* Not a sink - recursively explore each port found on this element */
for (i = 0; i < csdev->nr_outport; i++) {
struct coresight_device *child_dev = csdev->conns[i].child_dev;
if (child_dev &&
_coresight_build_path(child_dev, sink, path) == 0) {
found = true;
break;
}
}
if (!found)
return -ENODEV;
out:
/*
* A path from this element to a sink has been found. The elements
* leading to the sink are already enqueued, all that is left to do
* is tell the PM runtime core we need this element and add a node
* for it.
*/
node = kzalloc(sizeof(struct coresight_node), GFP_KERNEL);
if (!node)
return -ENOMEM;
coresight_grab_device(csdev);
node->csdev = csdev;
list_add(&node->link, path);
return 0;
}
struct list_head *coresight_build_path(struct coresight_device *source,
struct coresight_device *sink)
{
struct list_head *path;
int rc;
if (!sink)
return ERR_PTR(-EINVAL);
path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
if (!path)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(path);
rc = _coresight_build_path(source, sink, path);
if (rc) {
kfree(path);
return ERR_PTR(rc);
}
return path;
}
/**
* coresight_release_path - release a previously built path.
* @path: the path to release.
*
* Go through all the elements of a path and 1) removed it from the list and
* 2) free the memory allocated for each node.
*/
void coresight_release_path(struct list_head *path)
{
struct coresight_device *csdev;
struct coresight_node *nd, *next;
list_for_each_entry_safe(nd, next, path, link) {
csdev = nd->csdev;
coresight_drop_device(csdev);
list_del(&nd->link);
kfree(nd);
}
kfree(path);
path = NULL;
}
/** coresight_validate_source - make sure a source has the right credentials
* @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(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) {
dev_err(&csdev->dev, "wrong device subtype in %s\n", function);
return -EINVAL;
}
return 0;
}
int coresight_enable(struct coresight_device *csdev)
{
int cpu, ret = 0;
struct coresight_device *sink;
struct list_head *path;
enum coresight_dev_subtype_source subtype;
subtype = csdev->subtype.source_subtype;
mutex_lock(&coresight_mutex);
ret = coresight_validate_source(csdev, __func__);
if (ret)
goto out;
if (csdev->enable) {
/*
* 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)
atomic_inc(csdev->refcnt);
goto out;
}
/*
* Search for a valid sink for this session but don't reset the
* "enable_sink" flag in sysFS. Users get to do that explicitly.
*/
sink = coresight_get_enabled_sink(false);
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(csdev, CS_MODE_SYSFS);
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;
}
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);
void coresight_disable(struct coresight_device *csdev)
{
int cpu, ret;
struct list_head *path = NULL;
mutex_lock(&coresight_mutex);
ret = coresight_validate_source(csdev, __func__);
if (ret)
goto out;
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;
}
coresight_disable_path(path);
coresight_release_path(path);
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", 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", 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,
},
{
.name = "helper",
},
};
static void coresight_device_release(struct device *dev)
{
struct coresight_device *csdev = to_coresight_device(dev);
kfree(csdev->conns);
kfree(csdev->refcnt);
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 (conn->child_name &&
!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 void coresight_fixup_device_conns(struct coresight_device *csdev)
{
int i;
for (i = 0; i < csdev->nr_outport; i++) {
struct coresight_connection *conn = &csdev->conns[i];
struct device *dev = NULL;
if (conn->child_name)
dev = bus_find_device_by_name(&coresight_bustype, NULL,
conn->child_name);
if (dev) {
conn->child_dev = to_coresight_device(dev);
/* and put reference from 'bus_find_device()' */
put_device(dev);
} else {
csdev->orphan = true;
conn->child_dev = NULL;
}
}
}
static int coresight_remove_match(struct device *dev, void *data)
{
int i;
struct coresight_device *csdev, *iterator;
struct coresight_connection *conn;
csdev = data;
iterator = to_coresight_device(dev);
/* No need to check oneself */
if (csdev == iterator)
return 0;
/*
* Circle throuch all the connection of that component. If we find
* a connection whose name matches @csdev, remove it.
*/
for (i = 0; i < iterator->nr_outport; i++) {
conn = &iterator->conns[i];
if (conn->child_dev == NULL)
continue;
if (!strcmp(dev_name(&csdev->dev), conn->child_name)) {
iterator->orphan = true;
conn->child_dev = NULL;
/* No need to continue */
break;
}
}
/*
* Returning '0' ensures that all known component on the
* bus will be checked.
*/
return 0;
}
static void coresight_remove_conns(struct coresight_device *csdev)
{
bus_for_each_dev(&coresight_bustype, NULL,
csdev, coresight_remove_match);
}
/**
* 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 ret;
int link_subtype;
int nr_refcnts = 1;
atomic_t *refcnts = NULL;
struct coresight_device *csdev;
csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
if (!csdev) {
ret = -ENOMEM;
goto err_out;
}
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_free_csdev;
}
csdev->refcnt = refcnts;
csdev->nr_inport = desc->pdata->nr_inport;
csdev->nr_outport = desc->pdata->nr_outport;
csdev->conns = desc->pdata->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) {
put_device(&csdev->dev);
/*
* All resources are free'd explicitly via
* coresight_device_release(), triggered from put_device().
*/
goto err_out;
}
mutex_lock(&coresight_mutex);
coresight_fixup_device_conns(csdev);
coresight_fixup_orphan_conns(csdev);
mutex_unlock(&coresight_mutex);
return csdev;
err_free_csdev:
kfree(csdev);
err_out:
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(coresight_register);
void coresight_unregister(struct coresight_device *csdev)
{
/* Remove references of that device in the topology */
coresight_remove_conns(csdev);
device_unregister(&csdev->dev);
}
EXPORT_SYMBOL_GPL(coresight_unregister);
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