Re: [PATCH 1/2] remoteproc: imx_dsp_rproc: add mandatory find_loaded_rsc_table op

[Iuliana Prodan <iuliana.prodan@nxp.com>]

On 7/17/2023 8:42 PM, Mathieu Poirier wrote:
> On Thu, Jul 13, 2023 at 01:42:20AM +0300, Iuliana Prodan (OSS) wrote:
>> From: Iuliana Prodan <iuliana.prodan@nxp.com>
>>
>> Add the .find_loaded_rsc_table operation for i.MX DSP.
>> We need it for inter-process communication between DSP
>> and main core.
>>
>> This callback is used to find the resource table (defined
>> in remote processor linker script) where the address of the
>> vrings along with the other allocated resources (carveouts etc)
>> are stored.
>> If this is not found, the vrings are not allocated and
>> the IPC between cores will not work.
> Is there a constraint on the system memory the M4 can address?  If so there
> will be a need to declare address ranges for vrings and buffers in reserved
> memory in the DT.
>
> Thanks,
> Mathieu

Hi Mathieu,

No, there is no constraint on memory.

We want the Cortex A core to communicate with the HiFi4 DSP.
The Cortex A is in charge of starting the DSP and loading the firmware 
in HiFi4's memory.
When using rpmsg for IPC, the Cortex A needs to find the resource table 
(defined in the DSP linker script) and this is done using 
.find_loaded_rsc_table callback.

For the DT, we are using a (not upstream) device tree where we have the 
reserved-memory for dsp_vdev0vring0, dsp_vdev0vring1 and dsp_vdev0buffer.

Iulia


>> Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
>> ---
>>   drivers/remoteproc/imx_dsp_rproc.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/remoteproc/imx_dsp_rproc.c b/drivers/remoteproc/imx_dsp_rproc.c
>> index d95fa5586189..b5634507d953 100644
>> --- a/drivers/remoteproc/imx_dsp_rproc.c
>> +++ b/drivers/remoteproc/imx_dsp_rproc.c
>> @@ -941,6 +941,7 @@ static const struct rproc_ops imx_dsp_rproc_ops = {
>>   	.kick		= imx_dsp_rproc_kick,
>>   	.load		= imx_dsp_rproc_elf_load_segments,
>>   	.parse_fw	= imx_dsp_rproc_parse_fw,
>> +	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
>>   	.sanity_check	= rproc_elf_sanity_check,
>>   	.get_boot_addr	= rproc_elf_get_boot_addr,
>>   };
>> -- 
>> 2.17.1
>>