Programming CP_HQD_QUEUE_PRIORITY enables a queue to take priority over
other queues on the same pipe. Multiple queues on a pipe are timesliced
so this gives us full precedence over other queues.
Programming CP_HQD_PIPE_PRIORITY changes the SPI_ARB_PRIORITY of the
wave as follows:
0x2: CS_H
0x1: CS_M
0x0: CS_L
The SPI block will then dispatch work according to the policy set by
SPI_ARB_PRIORITY. In the current policy CS_H is higher priority than
gfx.
In order to prevent getting stuck in loops of resources bouncing between
GFX and high priority compute and introducing further latency, we
statically reserve a portion of the pipe.
v2: fix srbm_select to ring->queue and use ring->funcs->type
v3: use AMD_SCHED_PRIORITY_* instead of AMDGPU_CTX_PRIORITY_*
v4: switch int to enum amd_sched_priority
v5: corresponding changes for srbm_lock
v6: change CU reservation to PIPE_PERCENT allocation
v7: use kiq instead of MMIO
v8: back to MMIO, and make the implementation sleep safe.
v9: corresponding changes for splitting HIGH into _HW/_SW
Acked-by: Christian König <christian.koenig at amd.com>
Signed-off-by: Andres Rodriguez <andresx7 at gmail.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 4 ++
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +
drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c | 105 +++++++++++++++++++++++++++++
3 files changed, 111 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index b1e8cd9..7c6fca6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1114,6 +1114,10 @@ struct amdgpu_gfx {
bool in_suspend;
/* NGG */
struct amdgpu_ngg ngg;
+
+ /* pipe reservation */
+ struct mutex pipe_reserve_mutex;
+ DECLARE_BITMAP (pipe_reserve_bitmap, AMDGPU_MAX_COMPUTE_QUEUES);
};
int amdgpu_ib_get(struct amdgpu_device *adev, struct amdgpu_vm *vm,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index ae4387f..d7303d3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2019,6 +2019,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
adev->vm_manager.vm_pte_num_rings = 0;
adev->gart.gart_funcs = NULL;
adev->fence_context = dma_fence_context_alloc(AMDGPU_MAX_RINGS);
+ bitmap_zero(adev->gfx.pipe_reserve_bitmap, AMDGPU_MAX_COMPUTE_QUEUES);
adev->smc_rreg = &amdgpu_invalid_rreg;
adev->smc_wreg = &amdgpu_invalid_wreg;
@@ -2047,6 +2048,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
mutex_init(&adev->pm.mutex);
mutex_init(&adev->gfx.gpu_clock_mutex);
mutex_init(&adev->srbm_mutex);
+ mutex_init(&adev->gfx.pipe_reserve_mutex);
mutex_init(&adev->grbm_idx_mutex);
mutex_init(&adev->mn_lock);
hash_init(adev->mn_hash);
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index 1429242..bee5ef4 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -6461,6 +6461,110 @@ static void gfx_v8_0_ring_set_wptr_compute(struct amdgpu_ring *ring)
WDOORBELL32(ring->doorbell_index, lower_32_bits(ring->wptr));
}
+static void gfx_v8_0_ring_set_pipe_percent(struct amdgpu_ring *ring,
+ bool acquire)
+{
+ struct amdgpu_device *adev = ring->adev;
+ int pipe_num, tmp, reg;
+ int pipe_percent = acquire ? SPI_WCL_PIPE_PERCENT_GFX__VALUE_MASK : 0x1;
+
+ pipe_num = ring->me * adev->gfx.mec.num_pipe_per_mec + ring->pipe;
+
+ /* first me only has 2 entries, GFX and HP3D */
+ if (ring->me > 0)
+ pipe_num -= 2;
+
+ /* There is a bug in the GFX pipes that results in a HS
+ * deadlock if the pipe is restricted to a percentage
+ * lower than 17 */
+ if (ring->funcs->type != AMDGPU_RING_TYPE_COMPUTE && pipe_percent < 17)
+ pipe_percent = 17;
+
+ reg = mmSPI_WCL_PIPE_PERCENT_GFX + pipe_num;
+ tmp = RREG32(reg);
+ tmp = REG_SET_FIELD(tmp, SPI_WCL_PIPE_PERCENT_GFX, VALUE, pipe_percent);
+ WREG32(reg, tmp);
+}
+
+static void gfx_v8_0_pipe_reserve_resources(struct amdgpu_device *adev,
+ struct amdgpu_ring *ring,
+ bool acquire)
+{
+ int i, pipe;
+ bool reserve;
+ struct amdgpu_ring *iring;
+
+ mutex_lock(&adev->gfx.pipe_reserve_mutex);
+ pipe = amdgpu_gfx_queue_to_bit(adev, ring->me, ring->pipe, 0);
+ if (acquire)
+ set_bit(pipe, adev->gfx.pipe_reserve_bitmap);
+ else
+ clear_bit(pipe, adev->gfx.pipe_reserve_bitmap);
+
+ if (!bitmap_weight(adev->gfx.pipe_reserve_bitmap, AMDGPU_MAX_COMPUTE_QUEUES)) {
+ /* Clear all reservations - everyone reacquires all resources */
+ for (i = 0; i < adev->gfx.num_gfx_rings; ++i)
+ gfx_v8_0_ring_set_pipe_percent(&adev->gfx.gfx_ring[i],
+ true);
+
+ for (i = 0; i < adev->gfx.num_compute_rings; ++i)
+ gfx_v8_0_ring_set_pipe_percent(&adev->gfx.compute_ring[i],
+ true);
+ } else {
+ /* Lower all pipes without a current reservation */
+ for (i = 0; i < adev->gfx.num_gfx_rings; ++i) {
+ iring = &adev->gfx.gfx_ring[i];
+ pipe = amdgpu_gfx_queue_to_bit(adev,
+ iring->me,
+ iring->pipe,
+ 0);
+ reserve = test_bit(pipe, adev->gfx.pipe_reserve_bitmap);
+ gfx_v8_0_ring_set_pipe_percent(iring, reserve);
+ }
+
+ for (i = 0; i < adev->gfx.num_compute_rings; ++i) {
+ iring = &adev->gfx.compute_ring[i];
+ pipe = amdgpu_gfx_queue_to_bit(adev,
+ iring->me,
+ iring->pipe,
+ 0);
+ reserve = test_bit(pipe, adev->gfx.pipe_reserve_bitmap);
+ gfx_v8_0_ring_set_pipe_percent(iring, reserve);
+ }
+ }
+
+ mutex_unlock(&adev->gfx.pipe_reserve_mutex);
+}
+
+static void gfx_v8_0_hqd_set_priority(struct amdgpu_device *adev,
+ struct amdgpu_ring *ring,
+ bool acquire)
+{
+ uint32_t pipe_priority = acquire ? 0x2 : 0x0;
+ uint32_t queue_priority = acquire ? 0xf : 0x0;
+
+ mutex_lock(&adev->srbm_mutex);
+ vi_srbm_select(adev, ring->me, ring->pipe, ring->queue, 0);
+
+ WREG32(mmCP_HQD_PIPE_PRIORITY, pipe_priority);
+ WREG32(mmCP_HQD_QUEUE_PRIORITY, queue_priority);
+
+ vi_srbm_select(adev, 0, 0, 0, 0);
+ mutex_unlock(&adev->srbm_mutex);
+}
+static void gfx_v8_0_ring_set_priority_compute(struct amdgpu_ring *ring,
+ enum amd_sched_priority priority)
+{
+ struct amdgpu_device *adev = ring->adev;
+ bool acquire = priority == AMD_SCHED_PRIORITY_HIGH_HW;
+
+ if (ring->funcs->type != AMDGPU_RING_TYPE_COMPUTE)
+ return;
+
+ gfx_v8_0_hqd_set_priority(adev, ring, acquire);
+ gfx_v8_0_pipe_reserve_resources(adev, ring, acquire);
+}
+
static void gfx_v8_0_ring_emit_fence_compute(struct amdgpu_ring *ring,
u64 addr, u64 seq,
unsigned flags)
@@ -6906,6 +7010,7 @@ static const struct amdgpu_ring_funcs gfx_v8_0_ring_funcs_compute = {
.test_ib = gfx_v8_0_ring_test_ib,
.insert_nop = amdgpu_ring_insert_nop,
.pad_ib = amdgpu_ring_generic_pad_ib,
+ .set_priority = gfx_v8_0_ring_set_priority_compute,
};
static const struct amdgpu_ring_funcs gfx_v8_0_ring_funcs_kiq = {
--
2.9.3
