Re: [PATCH] accel/qaic: Support for 0 resize slice execution in BO

[Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>]

On Fri, Oct 27, 2023 at 10:43:30AM -0600, Jeffrey Hugo wrote:
> From: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
> 
> Add support to partially execute a slice which is resized to zero.
> Executing a zero size slice in a BO should mean that there is no DMA
> transfers involved but you should still configure doorbell and semaphores.
> 
> For example consider a BO of size 18K and it is sliced into 3 6K slices
> and user calls partial execute ioctl with resize as 10K.
> slice 0 - size is 6k and offset is 0, so resize of 10K will not cut short
>           this slice hence we send the entire slice for execution.
> slice 1 - size is 6k and offset is 6k, so resize of 10K will cut short this
>           slice and only the first 4k should be DMA along with configuring
>           doorbell and semaphores.
> slice 2 - size is 6k and offset is 12k, so resize of 10k will cut short
>           this slice and no DMA transfer would be involved but we should
>           would configure doorbell and semaphores.
> 
> This change begs to change the behavior of 0 resize. Currently, 0 resize
> partial execute ioctl behaves exactly like execute ioctl i.e. no resize.
> After this patch all the slice in BO should behave exactly like slice 2 in
> above example.
> 
> Refactor copy_partial_exec_reqs() to make it more readable and less
> complex.
> 
> Signed-off-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>
> Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
> Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>