On Thu, Jul 09, 2026 at 07:12:39PM +0530, Akhil P Oommen wrote:

On 7/7/2026 10:09 PM, Dmitry Baryshkov wrote:

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On Tue, Jul 07, 2026 at 05:02:43PM +0200, Anna Maniscalco wrote:

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On 7/6/26 5:04 PM, Dmitry Baryshkov wrote:

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On Sun, Jul 05, 2026 at 09:13:37PM +0200, Anna Maniscalco wrote:

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In order to associate the SID used by LPAC to it's own domain and
context bank we need a separate node on the DTS.

Can we use iommu-map instead of adding a new device using the same
addresses? You provide zero explanations, but it seems like you are
trying to separate a part of the GPU into a separate device, but it's
unnecessary.

What I was trying to say is that we need to map sid0 and sid1 to different
context banks.

From what I recall, so long as we use the same dt node, the iommu drivert
provides no way of doing this.

What kgsl does is having a node for the iommu and then subnodes for gfx lpac
and secure.

The address on the lpac device doesn't really matter. I have very limted
knowledge of DTSs but I think we could just leave it out altogether?

I think, you were poined to the Glymur Iris patches. Another option is
the QDA driver being submitted too. Both ot them use iommu-map to
describe the same usecase - a set of SIDs which are used by the device
but which should not be a part of the defaut set. With it in place you
don't need to have separate qcom,lpac devices, no additional properties,
etc. 

I'd recommend following the same approach.

iiuc, the conclusion in this recent thread is to use child nodes for a
similar case:
https://lore.kernel.org/all/20260618151745.GD231643@ziepe.ca/ (local)

Let me check internally.

-Akhil

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Add the code to look up that node on initialization.

Signed-off-by: Anna Maniscalco <redacted>
---
  drivers/gpu/drm/msm/adreno/adreno_gpu.c | 21 ++++++++++++++++++++-
  drivers/gpu/drm/msm/msm_gpu.h           |  1 +
  2 files changed, 21 insertions(+), 1 deletion(-)

Best regards,
-- 
Anna Maniscalco [off-list ref]

-- 
With best wishes
Dmitry