[PATCH v2 1/3] drm/amdgpu: Reject submissions with too many IBs.

[Bas Nieuwenhuizen]

Instead of failing somewhere in the scheduler after the
ioctl has already succeeded.

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2498
Signed-off-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_job.c  | 9 +++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 5 +++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h | 1 +
 3 files changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
index 995ee9ff65c9..8db6618b9049 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
@@ -113,6 +113,15 @@ int amdgpu_job_alloc(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	if (!entity)
 		return 0;
 
+	if (entity->rq && entity->rq->sched) {
+		struct amdgpu_ring *ring = to_amdgpu_ring(entity->rq->sched);
+
+		if (num_ibs > ring->max_ibs) {
+			DRM_DEBUG("Rejected a submission with too many IBs");
+			return -EINVAL;
+		}
+	}
+
 	return drm_sched_job_init(&(*job)->base, entity, owner);
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index dc474b809604..933cb95a0e30 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -324,6 +324,11 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
 	ring->max_dw = max_dw;
 	ring->hw_prio = hw_prio;
 
+	if (ring->funcs->emit_ib_size) {
+		ring->max_ibs =
+			(max_dw - ring->funcs->emit_frame_size) / ring->funcs->emit_ib_size;
+	}
+
 	if (!ring->no_scheduler) {
 		hw_ip = ring->funcs->type;
 		num_sched = &adev->gpu_sched[hw_ip][hw_prio].num_scheds;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
index 3989e755a5b4..7a295d80728b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
@@ -245,6 +245,7 @@ struct amdgpu_ring {
 	unsigned		ring_size;
 	unsigned		max_dw;
 	int			count_dw;
+	unsigned		max_ibs;
 	uint64_t		gpu_addr;
 	uint64_t		ptr_mask;
 	uint32_t		buf_mask;
-- 
2.40.0