Re: [PATCH v2 10/12] remoteproc: stm32: Introduce new parse fw ops for synchronisation

Bjorn Andersson
2020-05-14T05:15:08Z

On Fri 24 Apr 13:25 PDT 2020, Mathieu Poirier wrote:

> Introduce new parse firmware rproc_ops functions to be used when
> synchonising with an MCU.
>
> Mainly based on the work published by Arnaud Pouliquen [1].
>
> [1]. https://patchwork.kernel.org/project/linux-remoteproc/list/?series=239877
>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> Reviewed-by: Loic Pallardy <loic.pallardy@st.com>
> ---
> drivers/remoteproc/stm32_rproc.c | 51 +++++++++++++++++++++++++++++++-
> 1 file changed, 50 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
> index 86d23c35d805..b8ae8aed5585 100644
> --- a/drivers/remoteproc/stm32_rproc.c
> +++ b/drivers/remoteproc/stm32_rproc.c
> @@ -215,7 +215,34 @@ static int stm32_rproc_elf_load_rsc_table(struct rproc *rproc,
> return 0;
> }
>
> -static int stm32_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
> +static int stm32_rproc_sync_elf_load_rsc_table(struct rproc *rproc,
> + const struct firmware *fw)
> +{
> + struct resource_table *table = NULL;
> + struct stm32_rproc *ddata = rproc->priv;
> +
> + if (ddata->rsc_va) {

Does it really make sense to try to sync with a remote that doesn't have
a resource table?

> + table = (struct resource_table *)ddata->rsc_va;
> + /* Assuming that the resource table fits in 1kB is fair */
> + rproc->cached_table = kmemdup(table, RSC_TBL_SIZE, GFP_KERNEL);

It's unfortunate that we need to create a clone of the resource table
that we found in ram, and then return the original memory when the core
ask for the loaded table...

I wonder if we somehow can avoid this in the core (i.e. skip overwriting
table_ptr with the cached_table during stop)

> + if (!rproc->cached_table)
> + return -ENOMEM;
> +
> + rproc->table_ptr = rproc->cached_table;
> + rproc->table_sz = RSC_TBL_SIZE;
> + return 0;
> + }
> +
> + rproc->cached_table = NULL;
> + rproc->table_ptr = NULL;
> + rproc->table_sz = 0;
> +
> + dev_warn(&rproc->dev, "no resource table found for this firmware\n");
> + return 0;
> +}
> +
> +static int stm32_rproc_parse_memory_regions(struct rproc *rproc,
> + const struct firmware *fw)
> {
> struct device *dev = rproc->dev.parent;
> struct device_node *np = dev->of_node;
> @@ -268,9 +295,30 @@ static int stm32_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
> index++;
> }
>
> + return 0;
> +}
> +
> +static int stm32_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
> +{
> + int ret = stm32_rproc_parse_memory_regions(rproc, fw);
> +
> + if (ret)
> + return ret;
> +
> return stm32_rproc_elf_load_rsc_table(rproc, fw);
> }
>
> +static int stm32_rproc_sync_parse_fw(struct rproc *rproc,
> + const struct firmware *fw)

Rather than having a function parse_fw that is passed no fw and return
some state that was setup in probe, how about just do this during probe?

Regards,
Bjorn

> +{
> + int ret = stm32_rproc_parse_memory_regions(rproc, fw);
> +
> + if (ret)
> + return ret;
> +
> + return stm32_rproc_sync_elf_load_rsc_table(rproc, fw);
> +}
> +
> static irqreturn_t stm32_rproc_wdg(int irq, void *data)
> {
> struct platform_device *pdev = data;
> @@ -544,6 +592,7 @@ static struct rproc_ops st_rproc_ops = {
> static __maybe_unused struct rproc_ops st_rproc_sync_ops = {
> .start = stm32_rproc_sync_start,
> .stop = stm32_rproc_stop,
> + .parse_fw = stm32_rproc_sync_parse_fw,
> };
>
> static const struct of_device_id stm32_rproc_match[] = {
> --
> 2.20.1
>