[PATCH 13/16] drm/amdgpu/gfx11: rework kernel queue priority handling

[Alex Deucher <alexander.deucher@amd.com>]

Rather than setting a higher queue priority which could
starve a lower priority queue, enable longer quantums
for high priority kernel queues. This will avoid
starvation, but provide longer runtime for high priority
queues.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
index 121290f8b4930..6426270e9eb55 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
@@ -4130,6 +4130,12 @@ static int gfx_v11_0_gfx_mqd_init(struct amdgpu_device *adev, void *m,
 	/* set up time quantum */
 	tmp = regCP_GFX_HQD_QUANTUM_DEFAULT;
 	tmp = REG_SET_FIELD(tmp, CP_GFX_HQD_QUANTUM, QUANTUM_EN, 1);
+	/* increase the duration of a high priority kernel queue */
+	if (prop->kernel_queue &&
+	    (prop->hqd_pipe_priority == AMDGPU_GFX_PIPE_PRIO_HIGH))
+		tmp = REG_SET_FIELD(tmp, CP_GFX_HQD_QUANTUM, QUANTUM_DURATION, 20);
+	else
+		tmp = REG_SET_FIELD(tmp, CP_GFX_HQD_QUANTUM, QUANTUM_DURATION, 10);
 	mqd->cp_gfx_hqd_quantum = tmp;
 
 	/* set up gfx hqd base. this is similar as CP_RB_BASE */
@@ -4400,7 +4406,12 @@ static int gfx_v11_0_compute_mqd_init(struct amdgpu_device *adev, void *m,
 
 	tmp = REG_SET_FIELD(0, CP_HQD_QUANTUM, QUANTUM_EN, 1);
 	tmp = REG_SET_FIELD(tmp, CP_HQD_QUANTUM, QUANTUM_SCALE, 1);
-	tmp = REG_SET_FIELD(tmp, CP_HQD_QUANTUM, QUANTUM_DURATION, 1);
+	/* increase the duration of a high priority kernel queue */
+	if (prop->kernel_queue &&
+	    (prop->hqd_pipe_priority == AMDGPU_GFX_PIPE_PRIO_HIGH))
+		tmp = REG_SET_FIELD(tmp, CP_HQD_QUANTUM, QUANTUM_DURATION, 2);
+	else
+		tmp = REG_SET_FIELD(tmp, CP_HQD_QUANTUM, QUANTUM_DURATION, 1);
 	mqd->cp_hqd_quantum = tmp;
 
 	mqd->cp_hqd_active = prop->hqd_active;
-- 
2.53.0