[Mesa-dev] [PATCH 1/4] radeonsi: use CE suballocator for CP DMA realignment.

[Bas Nieuwenhuizen]

On Wed, Apr 20, 2016 at 2:13 AM, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
> On 19.04.2016 18:29, Bas Nieuwenhuizen wrote:
>>
>> I retract patch 1 and 2. Large scratch buffers are nice, but the
>> hardware only supports a 32-bit offset into it.
>
>
> Do you mean patch 2 and 3? Do you plan alternative patches to error out when
> there is an integer overflow? That's still kind of important...
>
> Cheers,
> Nicolai

Really, patch 1 and 2. I did patch 1 only so I did not need to make
the wole cp_dma work with pb_buffer.

Although I guess patch 3 can best be merged with the to be written
patch that checks that the resulting size fits in 32 bit.

- Bas

>
>>
>> - Bas
>>
>> On Wed, Apr 20, 2016 at 12:50 AM, Bas Nieuwenhuizen
>> <bas at basnieuwenhuizen.nl> wrote:
>>>
>>> Use the CE suballocator instead of the normal one as the usage
>>> is most similar to the CE, i.e. only read and written on GPU
>>> and not mapped to CPU.
>>>
>>> Signed-off-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
>>> ---
>>>   src/gallium/drivers/radeonsi/si_cp_dma.c | 27
>>> ++++++++++-----------------
>>>   1 file changed, 10 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/src/gallium/drivers/radeonsi/si_cp_dma.c
>>> b/src/gallium/drivers/radeonsi/si_cp_dma.c
>>> index 38e0ee6..264789d 100644
>>> --- a/src/gallium/drivers/radeonsi/si_cp_dma.c
>>> +++ b/src/gallium/drivers/radeonsi/si_cp_dma.c
>>> @@ -222,31 +222,24 @@ static void si_clear_buffer(struct pipe_context
>>> *ctx, struct pipe_resource *dst,
>>>    */
>>>   static void si_cp_dma_realign_engine(struct si_context *sctx, unsigned
>>> size)
>>>   {
>>> +
>>>          uint64_t va;
>>>          unsigned dma_flags = 0;
>>>          unsigned scratch_size = CP_DMA_ALIGNMENT * 2;
>>> +       unsigned offset;
>>> +       struct r600_resource *tmp_buf;
>>>
>>>          assert(size < CP_DMA_ALIGNMENT);
>>>
>>> -       /* Use the scratch buffer as the dummy buffer. The 3D engine
>>> should be
>>> -        * idle at this point.
>>> -        */
>>> -       if (!sctx->scratch_buffer ||
>>> -           sctx->scratch_buffer->b.b.width0 < scratch_size) {
>>> -               r600_resource_reference(&sctx->scratch_buffer, NULL);
>>> -               sctx->scratch_buffer =
>>> -                       si_resource_create_custom(&sctx->screen->b.b,
>>> -                                                 PIPE_USAGE_DEFAULT,
>>> -                                                 scratch_size);
>>> -               if (!sctx->scratch_buffer)
>>> -                       return;
>>> -               sctx->emit_scratch_reloc = true;
>>> -       }
>>> +       u_suballocator_alloc(sctx->ce_suballocator, scratch_size,
>>> &offset,
>>> +                            (struct pipe_resource**)&tmp_buf);
>>> +       if (!tmp_buf)
>>> +               return;
>>>
>>> -       si_cp_dma_prepare(sctx, &sctx->scratch_buffer->b.b,
>>> -                         &sctx->scratch_buffer->b.b, size, size,
>>> &dma_flags);
>>> +       si_cp_dma_prepare(sctx, &tmp_buf->b.b,
>>> +                         &tmp_buf->b.b, size, size, &dma_flags);
>>>
>>> -       va = sctx->scratch_buffer->gpu_address;
>>> +       va = tmp_buf->gpu_address + offset;
>>>          si_emit_cp_dma_copy_buffer(sctx, va, va + CP_DMA_ALIGNMENT,
>>> size,
>>>                                     dma_flags);
>>>   }
>>> --
>>> 2.8.0
>>>
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>