On Tue 14 Jul 12:50 PDT 2020, Mathieu Poirier wrote:
> 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.poir...@linaro.org>
> Reviewed-by: Arnaud Pouliquen <arnaud.pouliq...@st.com>
> Tested-by: Arnaud Pouliquen <arnaud.pouliq...@st.com>
Reviewed-by: Bjorn Andersson <bjorn.anders...@linaro.org>
> ---
> drivers/remoteproc/remoteproc_core.c | 18 ++++++++++++++++++
> drivers/remoteproc/remoteproc_sysfs.c | 16 ++++++++++++++--
> include/linux/remoteproc.h | 2 ++
> 3 files changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c
> b/drivers/remoteproc/remoteproc_core.c
> index 6b6e4ec8cf3a..099c76ab198f 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1624,6 +1624,14 @@ static int rproc_stop(struct rproc *rproc, bool
> crashed)
>
> rproc->state = RPROC_OFFLINE;
>
> + /*
> + * The remote processor has been stopped and is now offline, which means
> + * that the next time it is brought back online the remoteproc core will
> + * be responsible to load its firmware. As such it is no longer
> + * autonomous.
> + */
> + rproc->autonomous = false;
> +
> dev_info(dev, "stopped remote processor %s\n", rproc->name);
>
> return 0;
> @@ -2142,6 +2150,16 @@ int rproc_add(struct rproc *rproc)
> /* create debugfs entries */
> rproc_create_debug_dir(rproc);
>
> + /*
> + * Remind ourselves the remote processor has been attached to rather
> + * than booted by the remoteproc core. This is important because the
> + * RPROC_DETACHED state will be lost as soon as the remote processor
> + * has been attached to. Used in firmware_show() and reset in
> + * rproc_stop().
> + */
> + if (rproc->state == RPROC_DETACHED)
> + rproc->autonomous = true;
> +
> /* if rproc is marked always-on, request it to boot */
> if (rproc->auto_boot) {
> ret = rproc_trigger_auto_boot(rproc);
> diff --git a/drivers/remoteproc/remoteproc_sysfs.c
> b/drivers/remoteproc/remoteproc_sysfs.c
> index 264759713934..eea514cec50e 100644
> --- a/drivers/remoteproc/remoteproc_sysfs.c
> +++ b/drivers/remoteproc/remoteproc_sysfs.c
> @@ -15,8 +15,20 @@ static ssize_t firmware_show(struct device *dev, struct
> device_attribute *attr,
> char *buf)
> {
> struct rproc *rproc = to_rproc(dev);
> -
> - return sprintf(buf, "%s\n", rproc->firmware);
> + 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 */
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index bf6a310ba870..cf5e31556780 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -491,6 +491,7 @@ struct rproc_dump_segment {
> * @table_sz: size of @cached_table
> * @has_iommu: flag to indicate if remote processor is behind an MMU
> * @auto_boot: flag to indicate if remote processor should be auto-started
> + * @autonomous: true if an external entity has booted the remote processor
> * @dump_segments: list of segments in the firmware
> * @nb_vdev: number of vdev currently handled by rproc
> */
> @@ -524,6 +525,7 @@ struct rproc {
> size_t table_sz;
> bool has_iommu;
> bool auto_boot;
> + bool autonomous;
> struct list_head dump_segments;
> int nb_vdev;
> u8 elf_class;
> --
> 2.25.1
>
