[Mesa-stable] [Mesa-dev] [PATCH v3] radv: make sure to wait for CP DMA when needed

Bas Nieuwenhuizen bas at basnieuwenhuizen.nl
Wed Jul 11 08:49:39 UTC 2018


Reviewed-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>

On Mon, Jul 9, 2018 at 6:02 PM, Samuel Pitoiset
<samuel.pitoiset at gmail.com> wrote:
> This might fix some synchronization issues. I don't know if
> that will affect performance but it's required for correctness.
>
> v3: - wait for CP DMA in CmdPipelineBarrier()
>     - clear the busy value when CP_DMA_SYNC is requested
> v2: - wait for CP DMA in CmdWaitEvents()
>     - track if CP DMA is used
>
> CC: <mesa-stable at lists.freedesktop.org>
> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> ---
>  src/amd/vulkan/radv_cmd_buffer.c | 15 +++++++++++++
>  src/amd/vulkan/radv_private.h    |  5 +++++
>  src/amd/vulkan/si_cmd_buffer.c   | 36 ++++++++++++++++++++++++++++----
>  3 files changed, 52 insertions(+), 4 deletions(-)
>
> diff --git a/src/amd/vulkan/radv_cmd_buffer.c b/src/amd/vulkan/radv_cmd_buffer.c
> index 9da42fe03e..5dbdb3d996 100644
> --- a/src/amd/vulkan/radv_cmd_buffer.c
> +++ b/src/amd/vulkan/radv_cmd_buffer.c
> @@ -2596,6 +2596,11 @@ VkResult radv_EndCommandBuffer(
>                 si_emit_cache_flush(cmd_buffer);
>         }
>
> +       /* Make sure CP DMA is idle at the end of IBs because the kernel
> +        * doesn't wait for it.
> +        */
> +       si_cp_dma_wait_for_idle(cmd_buffer);
> +
>         vk_free(&cmd_buffer->pool->alloc, cmd_buffer->state.attachments);
>
>         if (!cmd_buffer->device->ws->cs_finalize(cmd_buffer->cs))
> @@ -4242,6 +4247,11 @@ radv_barrier(struct radv_cmd_buffer *cmd_buffer,
>                                              0);
>         }
>
> +       /* Make sure CP DMA is idle because the driver might have performed a
> +        * DMA operation for copying or filling buffers/images.
> +        */
> +       si_cp_dma_wait_for_idle(cmd_buffer);
> +
>         cmd_buffer->state.flush_bits |= dst_flush_bits;
>  }
>
> @@ -4292,6 +4302,11 @@ static void write_event(struct radv_cmd_buffer *cmd_buffer,
>                 VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT |
>                 VK_PIPELINE_STAGE_VERTEX_INPUT_BIT;
>
> +       /* Make sure CP DMA is idle because the driver might have performed a
> +        * DMA operation for copying or filling buffers/images.
> +        */
> +       si_cp_dma_wait_for_idle(cmd_buffer);
> +
>         /* TODO: Emit EOS events for syncing PS/CS stages. */
>
>         if (!(stageMask & ~top_of_pipe_flags)) {
> diff --git a/src/amd/vulkan/radv_private.h b/src/amd/vulkan/radv_private.h
> index 4e4b3a6037..2400de49a2 100644
> --- a/src/amd/vulkan/radv_private.h
> +++ b/src/amd/vulkan/radv_private.h
> @@ -979,6 +979,9 @@ struct radv_cmd_state {
>         uint32_t last_num_instances;
>         uint32_t last_first_instance;
>         uint32_t last_vertex_offset;
> +
> +       /* Whether CP DMA is busy/idle. */
> +       bool dma_is_busy;
>  };
>
>  struct radv_cmd_pool {
> @@ -1091,6 +1094,8 @@ void si_cp_dma_prefetch(struct radv_cmd_buffer *cmd_buffer, uint64_t va,
>                          unsigned size);
>  void si_cp_dma_clear_buffer(struct radv_cmd_buffer *cmd_buffer, uint64_t va,
>                             uint64_t size, unsigned value);
> +void si_cp_dma_wait_for_idle(struct radv_cmd_buffer *cmd_buffer);
> +
>  void radv_set_db_count_control(struct radv_cmd_buffer *cmd_buffer);
>  bool
>  radv_cmd_buffer_upload_alloc(struct radv_cmd_buffer *cmd_buffer,
> diff --git a/src/amd/vulkan/si_cmd_buffer.c b/src/amd/vulkan/si_cmd_buffer.c
> index 454fd8c39c..6d566a918d 100644
> --- a/src/amd/vulkan/si_cmd_buffer.c
> +++ b/src/amd/vulkan/si_cmd_buffer.c
> @@ -1040,7 +1040,6 @@ static void si_emit_cp_dma(struct radv_cmd_buffer *cmd_buffer,
>         struct radeon_cmdbuf *cs = cmd_buffer->cs;
>         uint32_t header = 0, command = 0;
>
> -       assert(size);
>         assert(size <= cp_dma_max_byte_count(cmd_buffer));
>
>         radeon_check_space(cmd_buffer->device->ws, cmd_buffer->cs, 9);
> @@ -1099,9 +1098,14 @@ static void si_emit_cp_dma(struct radv_cmd_buffer *cmd_buffer,
>          * indices. If we wanted to execute CP DMA in PFP, this packet
>          * should precede it.
>          */
> -       if ((flags & CP_DMA_SYNC) && cmd_buffer->queue_family_index == RADV_QUEUE_GENERAL) {
> -               radeon_emit(cs, PKT3(PKT3_PFP_SYNC_ME, 0, cmd_buffer->state.predicating));
> -               radeon_emit(cs, 0);
> +       if (flags & CP_DMA_SYNC) {
> +               if (cmd_buffer->queue_family_index == RADV_QUEUE_GENERAL) {
> +                       radeon_emit(cs, PKT3(PKT3_PFP_SYNC_ME, 0, cmd_buffer->state.predicating));
> +                       radeon_emit(cs, 0);
> +               }
> +
> +               /* CP will see the sync flag and wait for all DMAs to complete. */
> +               cmd_buffer->state.dma_is_busy = false;
>         }
>
>         if (unlikely(cmd_buffer->device->trace_bo))
> @@ -1165,6 +1169,8 @@ void si_cp_dma_buffer_copy(struct radv_cmd_buffer *cmd_buffer,
>         uint64_t main_src_va, main_dest_va;
>         uint64_t skipped_size = 0, realign_size = 0;
>
> +       /* Assume that we are not going to sync after the last DMA operation. */
> +       cmd_buffer->state.dma_is_busy = true;
>
>         if (cmd_buffer->device->physical_device->rad_info.family <= CHIP_CARRIZO ||
>             cmd_buffer->device->physical_device->rad_info.family == CHIP_STONEY) {
> @@ -1228,6 +1234,9 @@ void si_cp_dma_clear_buffer(struct radv_cmd_buffer *cmd_buffer, uint64_t va,
>
>         assert(va % 4 == 0 && size % 4 == 0);
>
> +       /* Assume that we are not going to sync after the last DMA operation. */
> +       cmd_buffer->state.dma_is_busy = true;
> +
>         while (size) {
>                 unsigned byte_count = MIN2(size, cp_dma_max_byte_count(cmd_buffer));
>                 unsigned dma_flags = CP_DMA_CLEAR;
> @@ -1243,6 +1252,25 @@ void si_cp_dma_clear_buffer(struct radv_cmd_buffer *cmd_buffer, uint64_t va,
>         }
>  }
>
> +void si_cp_dma_wait_for_idle(struct radv_cmd_buffer *cmd_buffer)
> +{
> +       if (cmd_buffer->device->physical_device->rad_info.chip_class < CIK)
> +               return;
> +
> +       if (!cmd_buffer->state.dma_is_busy)
> +               return;
> +
> +       /* Issue a dummy DMA that copies zero bytes.
> +        *
> +        * The DMA engine will see that there's no work to do and skip this
> +        * DMA request, however, the CP will see the sync flag and still wait
> +        * for all DMAs to complete.
> +        */
> +       si_emit_cp_dma(cmd_buffer, 0, 0, 0, CP_DMA_SYNC);
> +
> +       cmd_buffer->state.dma_is_busy = false;
> +}
> +
>  /* For MSAA sample positions. */
>  #define FILL_SREG(s0x, s0y, s1x, s1y, s2x, s2y, s3x, s3y)  \
>         (((s0x) & 0xf) | (((unsigned)(s0y) & 0xf) << 4) |                  \
> --
> 2.18.0
>
> _______________________________________________
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> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev


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