Re: [PATCH v9 4/7] remoteproc: core: Add TEE interface support for firmware release

Bjorn Andersson
2024-09-26T03:48:38Z

On Fri, Aug 30, 2024 at 11:51:44AM GMT, Arnaud Pouliquen wrote:
> Add support for releasing remote processor firmware through
> the Trusted Execution Environment (TEE) interface.
>
> The tee_rproc_release_fw() function is called in the following cases:
>
> - An error occurs in rproc_start() between the loading of the segments and
> the start of the remote processor.
> - When rproc_release_fw is called on error or after stopping the remote
> processor.
>
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
> ---
> drivers/remoteproc/remoteproc_core.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 7694817f25d4..32052dedc149 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -29,6 +29,7 @@
> #include <linux/debugfs.h>
> #include <linux/rculist.h>
> #include <linux/remoteproc.h>
> +#include <linux/remoteproc_tee.h>
> #include <linux/iommu.h>
> #include <linux/idr.h>
> #include <linux/elf.h>
> @@ -1258,6 +1259,9 @@ static int rproc_alloc_registered_carveouts(struct rproc *rproc)
>
> static void rproc_release_fw(struct rproc *rproc)
> {
> + if (rproc->state == RPROC_OFFLINE && rproc->tee_interface)
> + tee_rproc_release_fw(rproc);

I don't like the idea of having op-tee specific calls made from the
core. If the problem is that we need to unroll something we did at load,
can we instead come up with a more generic mechanism to unload that? Or
can we perhaps postpone the tee interaction until start() to avoid the
gap?

PS. Most of the Qualcomm drivers are TEE-based...so the "tee_interface"
boolean check here is not very nice.

Regards,
Bjorn

> +
> /* Free the copy of the resource table */
> kfree(rproc->cached_table);
> rproc->cached_table = NULL;
> @@ -1348,7 +1352,7 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
> if (ret) {
> dev_err(dev, "failed to prepare subdevices for %s: %d\n",
> rproc->name, ret);
> - goto reset_table_ptr;
> + goto release_fw;
> }
>
> /* power up the remote processor */
> @@ -1376,7 +1380,9 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
> rproc->ops->stop(rproc);
> unprepare_subdevices:
> rproc_unprepare_subdevices(rproc);
> -reset_table_ptr:
> +release_fw:
> + if (rproc->tee_interface)
> + tee_rproc_release_fw(rproc);
> rproc->table_ptr = rproc->cached_table;
>
> return ret;
> --
> 2.25.1
>