Re: [PATCH RFC 16/18] accel/qda: Add FastRPC-based DSP memory mapping support

[Krzysztof Kozlowski <krzk@kernel.org>]

On 23/02/2026 20:09, Ekansh Gupta wrote:
> Add a DRM_QDA_MAP ioctl and supporting FastRPC plumbing to map GEM
> backed buffers into the DSP virtual address space. The new
> qda_mem_map UAPI structure allows userspace to request legacy MMAP
> style mappings or handle-based MEM_MAP mappings with attributes, and
> encodes flags, offsets and optional virtual address hints that are
> forwarded to the DSP.
> 
> On the FastRPC side new method identifiers FASTRPC_RMID_INIT_MMAP
> and FASTRPC_RMID_INIT_MEM_MAP are introduced together with message
> structures for map requests and responses. The fastrpc_prepare_args
> path is extended to build the appropriate request headers, serialize
> the physical page information derived from a GEM object into a
> fastrpc_phy_page array and pack the arguments into the shared message
> buffer used by the existing invoke infrastructure.
> 
> The qda_ioctl_mmap() handler dispatches mapping requests based on the
> qda_mem_map request type, reusing the generic fastrpc_invoke()
> machinery and the RPMsg transport to communicate with the DSP. This
> provides the foundation for explicit buffer mapping into the DSP
> address space for subsequent FastRPC calls, aligned with the
> traditional FastRPC user space model.
> 
> Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
> ---
>  arch/arm64/configs/defconfig    |   2 +

Not relevan there. Don't stuff other subsystem code into your patches.
Especially without any reasons (your commit msg must explain WHY you are
doing things).

>  drivers/accel/qda/qda_drv.c     |   1 +
>  drivers/accel/qda/qda_fastrpc.c | 217 ++++++++++++++++++++++++++++++++++++++++
>  drivers/accel/qda/qda_fastrpc.h |  64 ++++++++++++
>  drivers/accel/qda/qda_ioctl.c   |  24 +++++
>  drivers/accel/qda/qda_ioctl.h   |  13 +++
>  include/uapi/drm/qda_accel.h    |  44 +++++++-
>  7 files changed, 364 insertions(+), 1 deletion(-)
> 



Best regards,
Krzysztof