Re: [PATCH v5] remoteproc: imx_dsp_rproc: add custom memory copy implementation for i.MX DSP Cores

Hi Mathieu,

On 3/1/2023 8:56 PM, Mathieu Poirier wrote:

On Wed, Mar 01, 2023 at 11:49:16AM -0700, Mathieu Poirier wrote:

quoted

Hi Iuliana,

On Tue, Feb 21, 2023 at 07:03:56PM +0200, Iuliana Prodan (OSS) wrote:

quoted

From: Iuliana Prodan <redacted>

The IRAM is part of the HiFi DSP.
According to hardware specification only 32-bits write are allowed
otherwise we get a Kernel panic.

Therefore add a custom memory copy and memset functions to deal with
the above restriction.

Signed-off-by: Iuliana Prodan <redacted>
---
Changes since v4
- use GENMASK;
- s/ioread32/readl;
- s/iowrite32/writel;
- use for loop with writel instead of __iowrite32_copy;
- update multi-line comment format.

This looks good now.  I will queue this on March 13th when 6.3-rc2 is out.

And out of curiosity, are the remote processors handled by imx_rproc.c also have
the same 32-bit write constraints?  If so, it would be nice to have a patch that
fixes that as well.  In such a case, imx_dsp_rproc_memcpy() and
imx_dsp_rproc_memset() should be renamed to something more generic and re-used
in imx_rproc.c.

None that I know of.

But, this restriction applies to any core who's writing to IRAM.
When one is writing from anywhere else in the system to IRAM, this is a PIF write.
And the inbound PIF writes are 32-bits at a time.

Thanks,

Iulia


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