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linux-next/drivers/remoteproc/remoteproc_sysfs.c
Mathieu Poirier 4a4dca1941 remoteproc: Properly handle firmware name when attaching
This patch prevents the firmware image name from being displayed when
the remoteproc core is attaching to a remote processor. This is needed
needed since there is no guarantee about the nature of the firmware
image that is loaded by the external entity.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Link: https://lore.kernel.org/r/20200714195035.1426873-10-mathieu.poirier@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2020-07-16 23:06:15 -07:00

175 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Remote Processor Framework
*/
#include <linux/remoteproc.h>
#include <linux/slab.h>
#include "remoteproc_internal.h"
#define to_rproc(d) container_of(d, struct rproc, dev)
/* Expose the loaded / running firmware name via sysfs */
static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct rproc *rproc = to_rproc(dev);
const char *firmware = rproc->firmware;
/*
* If the remote processor has been started by an external
* entity we have no idea of what image it is running. As such
* simply display a generic string rather then rproc->firmware.
*
* Here we rely on the autonomous flag because a remote processor
* may have been attached to and currently in a running state.
*/
if (rproc->autonomous)
firmware = "unknown";
return sprintf(buf, "%s\n", firmware);
}
/* Change firmware name via sysfs */
static ssize_t firmware_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct rproc *rproc = to_rproc(dev);
char *p;
int err, len = count;
err = mutex_lock_interruptible(&rproc->lock);
if (err) {
dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err);
return -EINVAL;
}
if (rproc->state != RPROC_OFFLINE) {
dev_err(dev, "can't change firmware while running\n");
err = -EBUSY;
goto out;
}
len = strcspn(buf, "\n");
if (!len) {
dev_err(dev, "can't provide a NULL firmware\n");
err = -EINVAL;
goto out;
}
p = kstrndup(buf, len, GFP_KERNEL);
if (!p) {
err = -ENOMEM;
goto out;
}
kfree(rproc->firmware);
rproc->firmware = p;
out:
mutex_unlock(&rproc->lock);
return err ? err : count;
}
static DEVICE_ATTR_RW(firmware);
/*
* A state-to-string lookup table, for exposing a human readable state
* via sysfs. Always keep in sync with enum rproc_state
*/
static const char * const rproc_state_string[] = {
[RPROC_OFFLINE] = "offline",
[RPROC_SUSPENDED] = "suspended",
[RPROC_RUNNING] = "running",
[RPROC_CRASHED] = "crashed",
[RPROC_DELETED] = "deleted",
[RPROC_DETACHED] = "detached",
[RPROC_LAST] = "invalid",
};
/* Expose the state of the remote processor via sysfs */
static ssize_t state_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct rproc *rproc = to_rproc(dev);
unsigned int state;
state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
return sprintf(buf, "%s\n", rproc_state_string[state]);
}
/* Change remote processor state via sysfs */
static ssize_t state_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct rproc *rproc = to_rproc(dev);
int ret = 0;
if (sysfs_streq(buf, "start")) {
if (rproc->state == RPROC_RUNNING)
return -EBUSY;
ret = rproc_boot(rproc);
if (ret)
dev_err(&rproc->dev, "Boot failed: %d\n", ret);
} else if (sysfs_streq(buf, "stop")) {
if (rproc->state != RPROC_RUNNING)
return -EINVAL;
rproc_shutdown(rproc);
} else {
dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
ret = -EINVAL;
}
return ret ? ret : count;
}
static DEVICE_ATTR_RW(state);
/* Expose the name of the remote processor via sysfs */
static ssize_t name_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct rproc *rproc = to_rproc(dev);
return sprintf(buf, "%s\n", rproc->name);
}
static DEVICE_ATTR_RO(name);
static struct attribute *rproc_attrs[] = {
&dev_attr_firmware.attr,
&dev_attr_state.attr,
&dev_attr_name.attr,
NULL
};
static const struct attribute_group rproc_devgroup = {
.attrs = rproc_attrs
};
static const struct attribute_group *rproc_devgroups[] = {
&rproc_devgroup,
NULL
};
struct class rproc_class = {
.name = "remoteproc",
.dev_groups = rproc_devgroups,
};
int __init rproc_init_sysfs(void)
{
/* create remoteproc device class for sysfs */
int err = class_register(&rproc_class);
if (err)
pr_err("remoteproc: unable to register class\n");
return err;
}
void __exit rproc_exit_sysfs(void)
{
class_unregister(&rproc_class);
}