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

From: Iuliana Prodan <iuliana.prodan@nxp.com>
To: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: "Iuliana Prodan (OSS)" <iuliana.prodan@oss.nxp.com>,
	Bjorn Andersson <andersson@kernel.org>,
	Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	"S.J. Wang" <shengjiu.wang@nxp.com>,
	Fabio Estevam <festevam@gmail.com>,
	Daniel Baluta <daniel.baluta@nxp.com>,
	Mpuaudiosw <Mpuaudiosw@nxp.com>, linux-imx <linux-imx@nxp.com>,
	linux-remoteproc@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	LnxRevLi <LnxRevLi@nxp.com>
Subject: Re: [PATCH 1/2] remoteproc: imx_dsp_rproc: add mandatory find_loaded_rsc_table op
Date: Tue, 18 Jul 2023 18:40:53 +0300	[thread overview]
Message-ID: <03d7c703-81cb-20f9-aaf8-2ab8ca3e7138@nxp.com> (raw)
In-Reply-To: <ZLauY85b9SRC3z0x@p14s>

On 7/18/2023 6:23 PM, Mathieu Poirier wrote:
> On Tue, Jul 18, 2023 at 11:25:03AM +0300, Iuliana Prodan wrote:
>> 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.
> That is the part I'm interested in.  Don't we need the reserved-memory entries?
> Otherwise the M4 may not be able to access the memory chosen by the application
> processor, most likely leading to a crash.

This kernel module (imx_dsp_rproc) is used only for DSP.
For M4 core we use imx_rproc.

Iulia

>> 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
>>>>

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