[Mesa-dev] [Mesa-stable] [PATCH v3] radv: make sure to wait for CP DMA when needed
Samuel Pitoiset
samuel.pitoiset at gmail.com
Thu Jul 12 08:03:35 UTC 2018
On 07/11/2018 06:52 PM, Dylan Baker wrote:
> Quoting Samuel Pitoiset (2018-07-09 09:02:58)
>> 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) | \
>
> Hi Samuel,
>
> I'm trying to get this to apply to 18.1 and having a heck of a time, git can't
> figure out how to apply this because of 8339ba827bf3f18463824206347665a45989b99e
> (radv: optimize vkCmd{Set,Reset}Event() a little bit), which doesn't seem
> suitable for stable and has other dependencies. I'm not confident in my ability
> to rebase this, if you'd still like this in 18.1, can you provide a patch that
> applies to the staging/18.1 branch in the main gitlab repo?
Hi Dylan,
Backport for 18.1 sent to mesa-stable. Thanks!
>
> Thanks,
> Dylan
>
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