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@xxxxxxxxxxx>
>> ---
>> 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.
