Hello Alex,
On 05/15/2018 10:53 PM, Alex Elder wrote:
> From: Bjorn Andersson <bjorn.anders...@linaro.org>
>
> On rare occasions a subdevice might need to prepare some hardware
> resources before a remote processor is booted, and clean up some
> state after it has been shut down.
>
> One such example is the IP Accelerator found in various Qualcomm
> platforms, which is accessed directly from both the modem remoteproc
> and the application subsystem and requires an intricate lockstep
> process when bringing the modem up and down.
>
> [el...@linaro.org: minor description and comment edits]
>
> Signed-off-by: Bjorn Andersson <bjorn.anders...@linaro.org>
> Acked-by: Alex Elder <el...@linaro.org>
> ---
> drivers/remoteproc/remoteproc_core.c | 56 ++++++++++++++++++++++++++--
> include/linux/remoteproc.h | 4 ++
> 2 files changed, 57 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c
> b/drivers/remoteproc/remoteproc_core.c
> index 2ede7ae6f5bc..283b258f5e0f 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -776,6 +776,30 @@ static int rproc_handle_resources(struct rproc *rproc,
> return ret;
> }
>
> +static int rproc_prepare_subdevices(struct rproc *rproc)
> +{
> + struct rproc_subdev *subdev;
> + int ret;
> +
> + list_for_each_entry(subdev, &rproc->subdevs, node) {
> + if (subdev->prepare) {
> + ret = subdev->prepare(subdev);
> + if (ret)
> + goto unroll_preparation;
> + }
> + }
> +
> + return 0;
> +
> +unroll_preparation:
> + list_for_each_entry_continue_reverse(subdev, &rproc->subdevs, node) {
> + if (subdev->unprepare)
> + subdev->unprepare(subdev);
> + }
Here you could call rproc_unprepare_subdevices instead of duplicating
the code.
regards
Arnaud
> +
> + return ret;
> +}
> +
> static int rproc_start_subdevices(struct rproc *rproc)
> {
> struct rproc_subdev *subdev;
> @@ -810,6 +834,16 @@ static void rproc_stop_subdevices(struct rproc *rproc,
> bool crashed)
> }
> }
>
> +static void rproc_unprepare_subdevices(struct rproc *rproc)
> +{
> + struct rproc_subdev *subdev;
> +
> + list_for_each_entry_reverse(subdev, &rproc->subdevs, node) {
> + if (subdev->unprepare)
> + subdev->unprepare(subdev);
> + }
> +}
> +
> /**
> * rproc_coredump_cleanup() - clean up dump_segments list
> * @rproc: the remote processor handle
> @@ -902,11 +936,18 @@ static int rproc_start(struct rproc *rproc, const
> struct firmware *fw)
> rproc->table_ptr = loaded_table;
> }
>
> + ret = rproc_prepare_subdevices(rproc);
> + if (ret) {
> + dev_err(dev, "failed to prepare subdevices for %s: %d\n",
> + rproc->name, ret);
> + return ret;
> + }
> +
> /* power up the remote processor */
> ret = rproc->ops->start(rproc);
> if (ret) {
> dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret);
> - return ret;
> + goto unprepare_subdevices;
> }
>
> /* Start any subdevices for the remote processor */
> @@ -914,8 +955,7 @@ static int rproc_start(struct rproc *rproc, const struct
> firmware *fw)
> if (ret) {
> dev_err(dev, "failed to probe subdevices for %s: %d\n",
> rproc->name, ret);
> - rproc->ops->stop(rproc);
> - return ret;
> + goto stop_rproc;
> }
>
> rproc->state = RPROC_RUNNING;
> @@ -923,6 +963,14 @@ static int rproc_start(struct rproc *rproc, const struct
> firmware *fw)
> dev_info(dev, "remote processor %s is now up\n", rproc->name);
>
> return 0;
> +
> +stop_rproc:
> + rproc->ops->stop(rproc);
> +
> +unprepare_subdevices:
> + rproc_unprepare_subdevices(rproc);
> +
> + return ret;
> }
>
> /*
> @@ -1035,6 +1083,8 @@ static int rproc_stop(struct rproc *rproc, bool crashed)
> return ret;
> }
>
> + rproc_unprepare_subdevices(rproc);
> +
> rproc->state = RPROC_OFFLINE;
>
> dev_info(dev, "stopped remote processor %s\n", rproc->name);
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 8f1426330cca..e3c5d856b6da 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -477,15 +477,19 @@ struct rproc {
> /**
> * struct rproc_subdev - subdevice tied to a remoteproc
> * @node: list node related to the rproc subdevs list
> + * @prepare: prepare function, called before the rproc is started
> * @start: start function, called after the rproc has been started
> * @stop: stop function, called before the rproc is stopped; the @crashed
> * parameter indicates if this originates from a recovery
> + * @unprepare: unprepare function, called after the rproc has been stopped
> */
> struct rproc_subdev {
> struct list_head node;
>
> + int (*prepare)(struct rproc_subdev *subdev);
> int (*start)(struct rproc_subdev *subdev);
> void (*stop)(struct rproc_subdev *subdev, bool crashed);
> + void (*unprepare)(struct rproc_subdev *subdev);
> };
>
> /* we currently support only two vrings per rvdev */
>
