Hello Bjorn,
On 9/26/24 05:51, Bjorn Andersson wrote:
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
As proposed in [1] an alternative could be to define a new rproc_ops->release_fw operation that will be initialized to tee_rproc_release_fw in the platform driver.
can we perhaps postpone the tee interaction until start() to avoid the gap?
In such a case, the management of the resource table should also be postponed as the firmware has to be authenticated first.
The OP-TEE implementation authenticates the firmware during the load (in-destination memory authentication), so the sequence is: 1) Load the firmware. 2) Get the resource table and initialize resources. 3) Start the firmware.
The tee_rproc_release_fw() is used if something goes wrong during step 2 an3.
From my perspective, this would result in an alternative boot sequence, as we have today for "attach". I proposed this approach in my V3 [2]. But this add complexity in remote proc core.
Please, could you align with Mathieu to define how we should move forward to address your concerns?
[1]https://lkml.org/lkml/2024/9/18/612 [2]https://lore.kernel.org/lkml/8af59b01-53cf-4fc4-9946-6c630fb7b38e@quicinc.co...
Thanks and Regards, Arnaud
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);return ret; -- 2.25.1