Re: [PATCH 3/3] remoteproc: Add coredump sysfs attribute

Mathieu Poirier
2020-04-23T20:48:02Z

On Thu, Apr 16, 2020 at 11:38:32AM -0700, Rishabh Bhatnagar wrote:
> Add coredump sysfs attribute to configure the type of memory dump.
> User can select between default or inline coredump functionality.
> Also coredump collection can be disabled through this interface.
> This functionality can be configured differently for different
> remote processors.
> This provides an option to dynamically configure the dump type
> based on userpsace capability.
>
> Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
> ---
> drivers/remoteproc/remoteproc_sysfs.c | 57 +++++++++++++++++++++++++++++++++++
> 1 file changed, 57 insertions(+)
>
> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
> index 7f8536b..d112664 100644
> --- a/drivers/remoteproc/remoteproc_sysfs.c
> +++ b/drivers/remoteproc/remoteproc_sysfs.c
> @@ -9,6 +9,62 @@
>
> #define to_rproc(d) container_of(d, struct rproc, dev)
>
> +/*
> + * A coredump-configuration-to-string lookup table, for exposing a
> + * human readable configuration via sysfs. Always keep in sync with
> + * enum rproc_coredump_conf
> + */
> +static const char * const rproc_coredump_str[] = {
> + [COREDUMP_DEFAULT] = "default",
> + [COREDUMP_INLINE] = "inline",
> + [COREDUMP_DISABLED] = "disabled",
> +};
> +
> +/* Expose the current coredump configuration via sysfs */
> +static ssize_t coredump_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct rproc *rproc = to_rproc(dev);
> +
> + return sprintf(buf, "%s\n", rproc_coredump_str[rproc->coredump_conf]);
> +}
> +
> +/* Change the coredump configuration via sysfs */
> +static ssize_t coredump_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct rproc *rproc = to_rproc(dev);
> + int err;
> +
> + 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_CRASHED) {
> + dev_err(dev, "can't change coredump configuration\n");
> + err = -EBUSY;
> + goto out;
> + }
> +
> + if (sysfs_streq(buf, "disable"))
> + rproc->coredump_conf = COREDUMP_DISABLED;
> + else if (sysfs_streq(buf, "inline"))
> + rproc->coredump_conf = COREDUMP_INLINE;
> + else if (sysfs_streq(buf, "default"))
> + rproc->coredump_conf = COREDUMP_DEFAULT;
> + else {
> + dev_err(dev, "Invalid coredump configuration\n");
> + err = -EINVAL;
> + }
> +out:
> + mutex_unlock(&rproc->lock);
> +
> + return err ? err : count;
> +}
> +static DEVICE_ATTR_RW(coredump);
> +
> /* Expose the loaded / running firmware name via sysfs */
> static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
> char *buf)
> @@ -127,6 +183,7 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
> &dev_attr_firmware.attr,
> &dev_attr_state.attr,
> &dev_attr_name.attr,
> + &dev_attr_coredump.attr,

This new entry needs to be documented in [1]. The set also needs to be rebased
on rproc-next.

Thanks,
Mathieu

[1]. https://elixir.bootlin.com/linux/v5.7-rc2/source/Documentation/ABI/testing/sysfs-class-remoteproc

> NULL
> };
>
> --
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