[PATCH 1/2] drm/kfd: Add CU occupancy support to GFX11

[David Belanger <david.belanger@amd.com>]

Port changes from GFX9 to GFX11 mostly as-is.
Minor changes to register access code.

Assisted-by: Claude:Sonnet 4.6
Signed-off-by: David Belanger <david.belanger@amd.com>
---
 .../drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c    | 148 ++++++++++++++++++
 1 file changed, 148 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c
index 724beb96ed1aa..46042f72741b4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v11.c
@@ -807,6 +807,153 @@ static uint32_t kgd_gfx_v11_hqd_sdma_get_doorbell(struct amdgpu_device *adev,
 	return 0;
 }
 
+static void lock_spi_csq_mutexes(struct amdgpu_device *adev)
+{
+	mutex_lock(&adev->srbm_mutex);
+	mutex_lock(&adev->grbm_idx_mutex);
+
+}
+
+static void unlock_spi_csq_mutexes(struct amdgpu_device *adev)
+{
+	mutex_unlock(&adev->grbm_idx_mutex);
+	mutex_unlock(&adev->srbm_mutex);
+}
+
+/**
+ * get_wave_count: Read device registers to get number of waves in flight for
+ * a particular queue. The method also returns the doorbell offset associated
+ * with the queue.
+ *
+ * @adev: Handle of device whose registers are to be read
+ * @queue_idx: Index of queue in the queue-map bit-field
+ * @queue_cnt: Stores the wave count and doorbell offset for an active queue
+ * @inst: xcc's instance number on a multi-XCC setup
+ */
+static void get_wave_count(struct amdgpu_device *adev, int queue_idx,
+		struct kfd_cu_occupancy *queue_cnt, uint32_t inst)
+{
+	int pipe_idx;
+	int queue_slot;
+	unsigned int reg_val;
+	unsigned int wave_cnt;
+	/*
+	 * Program GRBM with appropriate MEID, PIPEID, QUEUEID and VMID
+	 * parameters to read out waves in flight. Get VMID if there are
+	 * non-zero waves in flight.
+	 */
+	pipe_idx = queue_idx / adev->gfx.mec.num_queue_per_pipe;
+	queue_slot = queue_idx % adev->gfx.mec.num_queue_per_pipe;
+	soc21_grbm_select(adev, 1, pipe_idx, queue_slot, 0);
+	reg_val = RREG32_SOC15_IP(GC, SOC15_REG_OFFSET(GC, 0,
+				  regSPI_CSQ_WF_ACTIVE_COUNT_0) + queue_slot);
+	wave_cnt = reg_val & SPI_CSQ_WF_ACTIVE_COUNT_0__COUNT_MASK;
+	if (wave_cnt != 0) {
+		queue_cnt->wave_cnt += wave_cnt;
+		queue_cnt->doorbell_off =
+			(RREG32_SOC15(GC, 0, regCP_HQD_PQ_DOORBELL_CONTROL) &
+			 CP_HQD_PQ_DOORBELL_CONTROL__DOORBELL_OFFSET_MASK) >>
+			 CP_HQD_PQ_DOORBELL_CONTROL__DOORBELL_OFFSET__SHIFT;
+	}
+}
+
+/**
+ * kgd_gfx_v11_get_cu_occupancy: Reads relevant registers associated with each
+ * shader engine and aggregates the number of waves that are in flight for the
+ * process whose pasid is provided as a parameter. The process could have ZERO
+ * or more queues running and submitting waves to compute units.
+ *
+ * @adev: Handle of device from which to get number of waves in flight
+ * @cu_occupancy: Array that gets filled with wave_cnt and doorbell offset
+ *		  for comparison later.
+ * @max_waves_per_cu: Output parameter updated with maximum number of waves
+ *                    possible per Compute Unit
+ * @inst: xcc's instance number on a multi-XCC setup
+ *
+ * Note: It's possible that the device has too many queues (oversubscription)
+ * in which case a VMID could be remapped to a different PASID. This could lead
+ * to an inaccurate wave count. Following is a high-level sequence:
+ *    Time T1: vmid = getVmid(); vmid is associated with Pasid P1
+ *    Time T2: passId = getPasId(vmid); vmid is associated with Pasid P2
+ * In the sequence above wave count obtained from time T1 will be incorrectly
+ * lost or added to total wave count.
+ *
+ * The registers that provide the waves in flight are:
+ *
+ *  SPI_CSQ_WF_ACTIVE_STATUS - bit-map of queues per pipe. The bit is ON if a
+ *  queue is slotted, OFF if there is no queue. A process could have ZERO or
+ *  more queues slotted and submitting waves to be run on compute units. Even
+ *  when there is a queue it is possible there could be zero wave fronts, this
+ *  can happen when queue is waiting on top-of-pipe events - e.g. waitRegMem
+ *  command
+ *
+ *  For each bit that is ON from above:
+ *
+ *    Read (SPI_CSQ_WF_ACTIVE_COUNT_0 + queue_idx) register. It provides the
+ *    number of waves that are in flight for the queue at specified index. The
+ *    index ranges from 0 to 7.
+ *
+ *    If non-zero waves are in flight, store the corresponding doorbell offset
+ *    of the queue, along with the wave count.
+ *
+ *    Determine if the queue belongs to the process by comparing the doorbell
+ *    offset against the process's queues. If it matches, aggregate the wave
+ *    count for the process.
+ *
+ *  Reading registers referenced above involves programming GRBM appropriately
+ */
+static void kgd_gfx_v11_get_cu_occupancy(struct amdgpu_device *adev,
+				struct kfd_cu_occupancy *cu_occupancy,
+				int *max_waves_per_cu, uint32_t inst)
+{
+	int qidx;
+	int se_idx;
+	int se_cnt;
+	int queue_map;
+	int max_queue_cnt;
+	DECLARE_BITMAP(cp_queue_bitmap, AMDGPU_MAX_QUEUES);
+
+	lock_spi_csq_mutexes(adev);
+	soc21_grbm_select(adev, 1, 0, 0, 0);
+
+	/*
+	 * Iterate through the shader engines and arrays of the device
+	 * to get number of waves in flight
+	 */
+	bitmap_complement(cp_queue_bitmap, adev->gfx.mec_bitmap[0].queue_bitmap,
+			  AMDGPU_MAX_QUEUES);
+	max_queue_cnt = adev->gfx.mec.num_pipe_per_mec *
+			adev->gfx.mec.num_queue_per_pipe;
+	se_cnt = adev->gfx.config.max_shader_engines;
+	for (se_idx = 0; se_idx < se_cnt; se_idx++) {
+		amdgpu_gfx_select_se_sh(adev, se_idx, 0, 0xffffffff, inst);
+		queue_map = RREG32_SOC15(GC, 0,
+					 regSPI_CSQ_WF_ACTIVE_STATUS);
+
+		for (qidx = 0; qidx < max_queue_cnt; qidx++) {
+			/* Skip queues that are not associated with
+			 * compute functions
+			 */
+			if (!test_bit(qidx, cp_queue_bitmap))
+				continue;
+
+			if (!(queue_map & (1 << qidx)))
+				continue;
+
+			/* Get number of waves in flight and aggregate them */
+			get_wave_count(adev, qidx, &cu_occupancy[qidx], inst);
+		}
+	}
+
+	amdgpu_gfx_select_se_sh(adev, 0xffffffff, 0xffffffff, 0xffffffff, inst);
+	soc21_grbm_select(adev, 0, 0, 0, 0);
+	unlock_spi_csq_mutexes(adev);
+
+	/* Update the output parameters and return */
+	*max_waves_per_cu = adev->gfx.cu_info.simd_per_cu *
+				adev->gfx.cu_info.max_waves_per_simd;
+}
+
 const struct kfd2kgd_calls gfx_v11_kfd2kgd = {
 	.program_sh_mem_settings = program_sh_mem_settings_v11,
 	.set_pasid_vmid_mapping = set_pasid_vmid_mapping_v11,
@@ -832,5 +979,6 @@ const struct kfd2kgd_calls gfx_v11_kfd2kgd = {
 	.clear_address_watch = kgd_gfx_v11_clear_address_watch,
 	.hqd_get_pq_addr = kgd_gfx_v11_hqd_get_pq_addr,
 	.hqd_reset = kgd_gfx_v11_hqd_reset,
+	.get_cu_occupancy = kgd_gfx_v11_get_cu_occupancy,
 	.hqd_sdma_get_doorbell = kgd_gfx_v11_hqd_sdma_get_doorbell
 };
-- 
2.51.1