[PATCH 12/13] drm/amdgpu:changes in gfx DMAframe scheme
Christian König
deathsimple at vodafone.de
Mon Mar 27 16:16:52 UTC 2017
Am 24.03.2017 um 11:38 schrieb Monk Liu:
> 1) Adapt to vulkan:
> Now use double SWITCH BUFFER to replace the 128 nops w/a,
> because when vulkan introduced, umd can insert 7 ~ 16 IBs
> per submit which makes 256 DW size cannot hold the whole
> DMAframe (if we still insert those 128 nops), CP team suggests
> use double SWITCH_BUFFERs, instead of tricky 128 NOPs w/a.
>
> 2) To fix the CE VM fault issue when MCBP introduced:
> Need one more COND_EXEC wrapping IB part (original one us
> for VM switch part).
>
> this change can fix vm fault issue caused by below scenario
> without this change:
>
>> CE passed original COND_EXEC (no MCBP issued this moment),
> proceed as normal.
>
>> DE catch up to this COND_EXEC, but this time MCBP issued,
> thus DE treats all following packages as NOP. The following
> VM switch packages now looks just as NOP to DE, so DE
> dosen't do VM flush at all.
>
>> Now CE proceeds to the first IBc, and triggers VM fault,
> because DE didn't do VM flush for this DMAframe.
>
> 3) change estimated alloc size for gfx9.
> with new DMAframe scheme, we need modify emit_frame_size
> for gfx9
>
> with above changes, no more 128 NOPs w/a after VM flush
So we are back to square one? Cause that is exactly what we used to have
which you replaced with the 128 NOPs.
>
> Change-Id: Ib3f92d9d5a81bfff0369a00f23e1e5891797089a
> Signed-off-by: Monk Liu <Monk.Liu at amd.com>
Sorry for the delay, have been busy with tracking down a hardware issue.
First of all please fix your editor to correctly indent your code. This
file once more doesn't has correct indentation.
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c | 8 ++--
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 77 +++++++++++++++++++++-------------
> drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c | 29 ++++++++-----
> 3 files changed, 69 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> index d103270..b300929 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
> @@ -167,9 +167,6 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs,
> return r;
> }
>
> - if (ring->funcs->init_cond_exec)
> - patch_offset = amdgpu_ring_init_cond_exec(ring);
> -
> if (vm) {
> amdgpu_ring_insert_nop(ring, extra_nop); /* prevent CE go too fast than DE */
>
> @@ -180,7 +177,10 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned num_ibs,
> }
> }
>
> - if (ring->funcs->emit_hdp_flush
> + if (ring->funcs->init_cond_exec)
> + patch_offset = amdgpu_ring_init_cond_exec(ring);
> +
> + if (ring->funcs->emit_hdp_flush
Ok, so the conditional execution shouldn't cover the VM flush any more.
That makes perfect sense.
Maybe split that up as separate patch? Would make reviewing and editing
this one easier.
> #ifdef CONFIG_X86_64
> && !(adev->flags & AMD_IS_APU)
> #endif
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 9ff445c..74be4fa 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -483,42 +483,59 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job)
> id->oa_size != job->oa_size);
> int r;
>
> - if (ring->funcs->emit_pipeline_sync && (
> - job->vm_needs_flush || gds_switch_needed ||
> - amdgpu_vm_ring_has_compute_vm_bug(ring)))
> - amdgpu_ring_emit_pipeline_sync(ring);
> + if (job->vm_needs_flush || gds_switch_needed ||
> + amdgpu_vm_is_gpu_reset(adev, id) ||
> + amdgpu_vm_ring_has_compute_vm_bug(ring)) {
> + unsigned patch_offset = 0;
>
> - if (ring->funcs->emit_vm_flush && (job->vm_needs_flush ||
> - amdgpu_vm_is_gpu_reset(adev, id))) {
> - struct fence *fence;
> - u64 pd_addr = amdgpu_vm_adjust_mc_addr(adev, job->vm_pd_addr);
> + if (ring->funcs->init_cond_exec)
> + patch_offset = amdgpu_ring_init_cond_exec(ring);
Ok, why are you inserting a cond_exec for the VM flush here?
>
> - trace_amdgpu_vm_flush(pd_addr, ring->idx, job->vm_id);
> - amdgpu_ring_emit_vm_flush(ring, job->vm_id, pd_addr);
> + if (ring->funcs->emit_pipeline_sync &&
> + (job->vm_needs_flush || gds_switch_needed ||
> + amdgpu_vm_ring_has_compute_vm_bug(ring)))
> + amdgpu_ring_emit_pipeline_sync(ring);
>
> - r = amdgpu_fence_emit(ring, &fence);
> - if (r)
> - return r;
> + if (ring->funcs->emit_vm_flush && (job->vm_needs_flush ||
> + amdgpu_vm_is_gpu_reset(adev, id))) {
> + struct fence *fence;
> + u64 pd_addr = amdgpu_vm_adjust_mc_addr(adev, job->vm_pd_addr);
>
> - mutex_lock(&adev->vm_manager.lock);
> - fence_put(id->last_flush);
> - id->last_flush = fence;
> - mutex_unlock(&adev->vm_manager.lock);
> - }
> + trace_amdgpu_vm_flush(pd_addr, ring->idx, job->vm_id);
> + amdgpu_ring_emit_vm_flush(ring, job->vm_id, pd_addr);
>
> - if (gds_switch_needed) {
> - id->gds_base = job->gds_base;
> - id->gds_size = job->gds_size;
> - id->gws_base = job->gws_base;
> - id->gws_size = job->gws_size;
> - id->oa_base = job->oa_base;
> - id->oa_size = job->oa_size;
> - amdgpu_ring_emit_gds_switch(ring, job->vm_id,
> - job->gds_base, job->gds_size,
> - job->gws_base, job->gws_size,
> - job->oa_base, job->oa_size);
> - }
> + r = amdgpu_fence_emit(ring, &fence);
> + if (r)
> + return r;
>
> + mutex_lock(&adev->vm_manager.lock);
> + fence_put(id->last_flush);
> + id->last_flush = fence;
> + mutex_unlock(&adev->vm_manager.lock);
> + }
> +
> + if (gds_switch_needed) {
> + id->gds_base = job->gds_base;
> + id->gds_size = job->gds_size;
> + id->gws_base = job->gws_base;
> + id->gws_size = job->gws_size;
> + id->oa_base = job->oa_base;
> + id->oa_size = job->oa_size;
> + amdgpu_ring_emit_gds_switch(ring, job->vm_id,
> + job->gds_base, job->gds_size,
> + job->gws_base, job->gws_size,
> + job->oa_base, job->oa_size);
> + }
> +
> + if (ring->funcs->patch_cond_exec)
> + amdgpu_ring_patch_cond_exec(ring, patch_offset);
> +
> + /* the double SWITCH_BUFFER here *cannot* be skipped by COND_EXEC */
> + if (ring->funcs->emit_switch_buffer) {
> + amdgpu_ring_emit_switch_buffer(ring);
> + amdgpu_ring_emit_switch_buffer(ring);
> + }
> + }
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> index ce6fa03..eb8551b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> @@ -3134,8 +3134,6 @@ static void gfx_v9_0_ring_emit_vm_flush(struct amdgpu_ring *ring,
> /* sync PFP to ME, otherwise we might get invalid PFP reads */
> amdgpu_ring_write(ring, PACKET3(PACKET3_PFP_SYNC_ME, 0));
> amdgpu_ring_write(ring, 0x0);
> - /* Emits 128 dw nop to prevent CE access VM before vm_flush finish */
> - amdgpu_ring_insert_nop(ring, 128);
If this isn't needed any more you should remove that from gfx8 and gfx7
as well.
Regards,
Christian.
> }
> }
>
> @@ -3629,15 +3627,24 @@ static const struct amdgpu_ring_funcs gfx_v9_0_ring_funcs_gfx = {
> .get_rptr = gfx_v9_0_ring_get_rptr_gfx,
> .get_wptr = gfx_v9_0_ring_get_wptr_gfx,
> .set_wptr = gfx_v9_0_ring_set_wptr_gfx,
> - .emit_frame_size =
> - 20 + /* gfx_v9_0_ring_emit_gds_switch */
> - 7 + /* gfx_v9_0_ring_emit_hdp_flush */
> - 5 + /* gfx_v9_0_ring_emit_hdp_invalidate */
> - 8 + 8 + 8 +/* gfx_v9_0_ring_emit_fence x3 for user fence, vm fence */
> - 7 + /* gfx_v9_0_ring_emit_pipeline_sync */
> - 128 + 66 + /* gfx_v9_0_ring_emit_vm_flush */
> - 2 + /* gfx_v9_ring_emit_sb */
> - 3, /* gfx_v9_ring_emit_cntxcntl */
> + .emit_frame_size = /* totally 242 maximum if 16 IBs */
> + 5 + /* COND_EXEC */
> + 7 + /* PIPELINE_SYNC */
> + 46 + /* VM_FLUSH */
> + 8 + /* FENCE for VM_FLUSH */
> + 20 + /* GDS switch */
> + 4 + /* double SWITCH_BUFFER,
> + the first COND_EXEC jump to the place just
> + prior to this double SWITCH_BUFFER */
> + 5 + /* COND_EXEC */
> + 7 + /* HDP_flush */
> + 4 + /* VGT_flush */
> + 14 + /* CE_META */
> + 31 + /* DE_META */
> + 3 + /* CNTX_CTRL */
> + 5 + /* HDP_INVL */
> + 8 + 8 + /* FENCE x2 */
> + 2, /* SWITCH_BUFFER */
> .emit_ib_size = 4, /* gfx_v9_0_ring_emit_ib_gfx */
> .emit_ib = gfx_v9_0_ring_emit_ib_gfx,
> .emit_fence = gfx_v9_0_ring_emit_fence,
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