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Message-ID: <f070f6e0-275c-1937-2bde-adee0c1fd08e@imgtec.com>
Date: Thu, 13 Oct 2016 15:25:54 +0100
From: Matt Redfearn <matt.redfearn@...tec.com>
To: loic pallardy <loic.pallardy@...com>,
Bjorn Andersson <bjorn.andersson@...aro.org>,
Ohad Ben-Cohen <ohad@...ery.com>
CC: <linux-remoteproc@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/4] remoteproc: Add a sysfs interface for firmware and
state
Hi Loic,
On 13/10/16 14:56, loic pallardy wrote:
>
>
> On 10/11/2016 03:39 PM, Matt Redfearn wrote:
>> This patch adds a sysfs interface to rproc allowing the firmware name
>> and processor state to be changed dynamically.
>>
>> State was previously available in debugfs, and is replicated here. The
>> firmware file allows retrieval of the running firmware name, and a new
>> one to be specified at run time, so long as the remote processor has
>> been stopped.
>>
>> Signed-off-by: Matt Redfearn <matt.redfearn@...tec.com>
>>
>> ---
>>
>> Documentation/ABI/testing/sysfs-class-remoteproc | 50 +++++++++
>> drivers/remoteproc/Makefile | 1 +
>> drivers/remoteproc/remoteproc_core.c | 3 +
>> drivers/remoteproc/remoteproc_internal.h | 5 +
>> drivers/remoteproc/remoteproc_sysfs.c | 132
>> +++++++++++++++++++++++
>> 5 files changed, 191 insertions(+)
>> create mode 100644 Documentation/ABI/testing/sysfs-class-remoteproc
>> create mode 100644 drivers/remoteproc/remoteproc_sysfs.c
>>
>> diff --git a/Documentation/ABI/testing/sysfs-class-remoteproc
>> b/Documentation/ABI/testing/sysfs-class-remoteproc
>> new file mode 100644
>> index 000000000000..d188afebc8ba
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-class-remoteproc
>> @@ -0,0 +1,50 @@
>> +What: /sys/class/remoteproc/.../firmware
>> +Date: October 2016
>> +Contact: Matt Redfearn <matt.redfearn@...tec.com>
>> +Description: Remote processor firmware
>> +
>> + Reports the name of the firmware currently loaded to the
>> + remote processor.
>> +
>> + To change the running firmware, ensure the remote processor is
>> + stopped (using /sys/class/remoteproc/.../state) and write a
>> new filename.
>> +
>> +What: /sys/class/remoteproc/.../state
>> +Date: October 2016
>> +Contact: Matt Redfearn <matt.redfearn@...tec.com>
>> +Description: Remote processor state
>> +
>> + Reports the state of the remote processor, which will be one
>> of:
>> +
>> + "offline"
>> + "suspended"
>> + "running"
>> + "crashed"
>> + "invalid"
>> +
>> + "offline" means the remote processor is powered off.
>> +
>> + "suspended" means that the remote processor is suspended and
>> + must be woken to receive messages.
>> +
>> + "running" is the normal state of an available remote processor
>> +
>> + "crashed" indicates that a problem/crash has been detected on
>> + the remote processor.
>> +
>> + "invalid" is returned if the remote processor is in an
>> + unknown state.
>> +
>> + Writing this file controls the state of the remote processor.
>> + The following states can be written:
>> +
>> + "start"
>> + "stop"
>> +
>> + Writing "start" will attempt to start the processor running the
>> + firmware indicated by, or written to,
>> + /sys/class/remoteproc/.../firmware. The remote processor should
>> + transition to "running" state.
>> +
>> + Writing "stop" will attempt to halt the remote processor and
>> + return it to the "offline" state.
>> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
>> index 92d3758bd15c..666258bd80aa 100644
>> --- a/drivers/remoteproc/Makefile
>> +++ b/drivers/remoteproc/Makefile
>> @@ -5,6 +5,7 @@
>> obj-$(CONFIG_REMOTEPROC) += remoteproc.o
>> remoteproc-y := remoteproc_core.o
>> remoteproc-y += remoteproc_debugfs.o
>> +remoteproc-y += remoteproc_sysfs.o
>> remoteproc-y += remoteproc_virtio.o
>> remoteproc-y += remoteproc_elf_loader.o
>> obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o
>> diff --git a/drivers/remoteproc/remoteproc_core.c
>> b/drivers/remoteproc/remoteproc_core.c
>> index 2152b484f314..642c5b58fec5 100644
>> --- a/drivers/remoteproc/remoteproc_core.c
>> +++ b/drivers/remoteproc/remoteproc_core.c
>> @@ -1455,6 +1455,7 @@ struct rproc *rproc_alloc(struct device *dev,
>> const char *name,
>> device_initialize(&rproc->dev);
>> rproc->dev.parent = dev;
>> rproc->dev.type = &rproc_type;
>> + rproc->dev.class = &rproc_class;
>>
>> /* Assign a unique device index and name */
>> rproc->index = ida_simple_get(&rproc_dev_index, 0, 0, GFP_KERNEL);
>> @@ -1580,6 +1581,7 @@ EXPORT_SYMBOL(rproc_report_crash);
>>
>> static int __init remoteproc_init(void)
>> {
>> + rproc_init_sysfs();
>> rproc_init_debugfs();
>>
>> return 0;
>> @@ -1591,6 +1593,7 @@ static void __exit remoteproc_exit(void)
>> ida_destroy(&rproc_dev_index);
>>
>> rproc_exit_debugfs();
>> + rproc_exit_sysfs();
>> }
>> module_exit(remoteproc_exit);
>>
>> diff --git a/drivers/remoteproc/remoteproc_internal.h
>> b/drivers/remoteproc/remoteproc_internal.h
>> index 837faf2677a6..2beb86ddfacc 100644
>> --- a/drivers/remoteproc/remoteproc_internal.h
>> +++ b/drivers/remoteproc/remoteproc_internal.h
>> @@ -64,6 +64,11 @@ void rproc_create_debug_dir(struct rproc *rproc);
>> void rproc_init_debugfs(void);
>> void rproc_exit_debugfs(void);
>>
>> +/* from remoteproc_sysfs.c */
>> +extern struct class rproc_class;
> struct class rproc_class should be static to remoteproc_sysfs.c file.
> It will be better to create a new interface like rproc_register_sysfs
> to associate rproc_class to rproc device.
It would be nice if that were possible, but since the class has to
associated with the devices created within remoteproc_core, as it stands
we must have visibility of this symbol there, see above the change to
drivers/remoteproc/remoteproc_core.c line 1455.
The alternative would be a utility function in remoteproc_sysfs.c to
associate the class with an rproc device, it depends what the preference
would be.
Thanks,
Matt
>
>> +int rproc_init_sysfs(void);
>> +void rproc_exit_sysfs(void);
>> +
>> void rproc_free_vring(struct rproc_vring *rvring);
>> int rproc_alloc_vring(struct rproc_vdev *rvdev, int i);
>>
>> diff --git a/drivers/remoteproc/remoteproc_sysfs.c
>> b/drivers/remoteproc/remoteproc_sysfs.c
>> new file mode 100644
>> index 000000000000..892599863ca6
>> --- /dev/null
>> +++ b/drivers/remoteproc/remoteproc_sysfs.c
>> @@ -0,0 +1,132 @@
>> +/*
>> + * Remote Processor Framework
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * 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/remoteproc.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);
>> +
>> + if (rproc->firmware)
>> + return sprintf(buf, "%s\n", rproc->firmware);
>> + else
>> + return sprintf(buf, "unknown");
>> +}
>> +
>> +/* 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);
>> + int err;
>> +
>> + err = rproc_change_firmware(rproc, buf);
>> + 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[] = {
>> + "offline",
>> + "suspended",
>> + "running",
>> + "crashed",
>> + "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 scnprintf(buf, 30, "%.28s (%d)\n",
>> + rproc_state_string[state], rproc->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;
>> + int len = count;
>> +
>> + if (buf[len - 1] == '\n')
>> + len--;
>> +
>> + if (!strncmp(buf, "start", len)) {
>> + if (rproc->state == RPROC_RUNNING)
>> + return -EBUSY;
>> +
>> + ret = rproc_boot(rproc);
>> + if (ret)
>> + dev_err(&rproc->dev, "Boot failed: %d\n", ret);
>> + } else if (!strncmp(buf, "stop", len)) {
>> + rproc_shutdown(rproc);
>> + } else {
>> + dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
>> + ret = -EINVAL;
>> + }
>> + return ret ? ret : count;
>> +}
>> +static DEVICE_ATTR_RW(state);
>> +
>> +static const struct attribute *rproc_attrs[] = {
>> + &dev_attr_firmware.attr,
>> + &dev_attr_state.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 = {
> static ?
>
> Regards,
> Loic
>> + .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);
>> +}
>>
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