[PATCH] remoteproc: pru: Fix firmware loading crashes on K3 SoCs

[Suman Anna]

On 3/25/21 3:09 PM, Suman Anna wrote:
> On 3/25/21 12:36 PM, Mathieu Poirier wrote:
>> On Wed, 24 Mar 2021 at 11:09, Suman Anna <s-anna at ti.com> wrote:
>>>
>>> On 3/23/21 6:20 PM, Mathieu Poirier wrote:
>>>> On Mon, Mar 15, 2021 at 03:58:59PM -0500, Suman Anna wrote:
>>>>> The K3 PRUs are 32-bit processors and in general have some limitations
>>>>> in using the standard ARMv8 memcpy function for loading firmware segments,
>>>>> so the driver already uses a custom memcpy implementation. This added
>>>>> logic however is limited to only IRAMs at the moment, but the loading
>>>>> into Data RAMs is not completely ok either and does generate a kernel
>>>>> crash for unaligned accesses.
>>>>>
>>>>> Fix these crashes by removing the existing IRAM logic limitation and
>>>>> extending the custom memcpy usage to Data RAMs as well for all K3 SoCs.
>>>>>
>>>>> Fixes: 1d39f4d19921 ("remoteproc: pru: Add support for various PRU cores on K3 AM65x SoCs")
>>>>> Signed-off-by: Suman Anna <s-anna at ti.com>
>>>>
>>>> Probably a good idea to CC stable as well...
>>>>
>>>> Reviewed-by: Mathieu Poirier <mathieu.poirier at linaro.org>
>>>
>>> Thanks Mathieu. This patch is already staged on Bjorn's rproc-fixes branch
>>> though and part of linux-next since next-20210319. I have posted an additional
>>> 3-patch series for some more PRU fixes. Do you want me to post a v2 for those
>>> with stable Cc'd?
>>
>> I didn't notice Bjorn had already picked it up.  Since the object is
>> now public there is no need to send a V2 for this one.  I haven't
>> looked at your other 3-patch series but if you think it is stable
>> material then yes, please send a new revision that CC stable.
> 
> Alright, will do.

On a second thought, we don't have any dts nodes in-kernel yet (5.13-rc1 would
be the first kernel with PRU nodes), so those are not critical for v5.11 kernel.
As long as they get fixed in either the current v5.12-rc's or by v5.13-rc1, we
will be fine.

regards
Suman

> 
> regards
> Suman
> 
>>
>> Mathieu
>>
>>>
>>> regards
>>> Suman
>>>
>>>>
>>>>> ---
>>>>>  drivers/remoteproc/pru_rproc.c | 2 +-
>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
>>>>> index 2667919d76b3..16979c1cd2f4 100644
>>>>> --- a/drivers/remoteproc/pru_rproc.c
>>>>> +++ b/drivers/remoteproc/pru_rproc.c
>>>>> @@ -585,7 +585,7 @@ pru_rproc_load_elf_segments(struct rproc *rproc, const struct firmware *fw)
>>>>>                      break;
>>>>>              }
>>>>>
>>>>> -            if (pru->data->is_k3 && is_iram) {
>>>>> +            if (pru->data->is_k3) {
>>>>>                      ret = pru_rproc_memcpy(ptr, elf_data + phdr->p_offset,
>>>>>                                             filesz);
>>>>>                      if (ret) {
>>>>> --
>>>>> 2.30.1
>>>>>
>>>
>