[AMD Public Use]
Some minor typos
> -----Original Message-----
> From: amd-gfx <amd-gfx-boun...@lists.freedesktop.org> On Behalf Of Ramesh
> Errabolu
> Sent: Friday, September 25, 2020 6:03 PM
> To: amd-gfx@lists.freedesktop.org
> Cc: Errabolu, Ramesh <ramesh.errab...@amd.com>
> Subject: [PATCH 2/3] drm/amd/amdgpu: Define and implement a function that
> collects
> number of waves that are in flight.
>
> [Why]
> Allow user to know how many compute units (CU) are in use at any given
> moment.
>
> [How]
> Read registers of SQ that give number of waves that are in flight
> of various queues. Use this information to determine number of CU's
> in use.
>
> Signed-off-by: Ramesh Errabolu <ramesh.errab...@amd.com>
> ---
> .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c | 176 +++++++++++++++++-
> .../gpu/drm/amd/include/kgd_kfd_interface.h | 12 ++
> 2 files changed, 187 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> index e6aede725197..87d4c8855805 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> @@ -38,7 +38,7 @@
> #include "soc15d.h"
> #include "mmhub_v1_0.h"
> #include "gfxhub_v1_0.h"
> -
> +#include "gfx_v9_0.h"
>
> enum hqd_dequeue_request_type {
> NO_ACTION = 0,
> @@ -706,6 +706,179 @@ void kgd_gfx_v9_set_vm_context_page_table_base(struct
> kgd_dev *kgd,
> gfxhub_v1_0_setup_vm_pt_regs(adev, vmid, page_table_base);
> }
>
> +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 particulare queue. The method also returns the VMID associated with the
particular
> + * queue.
> + *
> + * @adev: Handle of device whose registers are to be read
> + * @queue_idx: Index of queue in the queue-map bit-field
> + * @wave_cnt: Output parameter updated with number of waves in flight
> + * @vmid: Output parameter updated with VMID of queue whose wave count
> + * is being collected
> + */
> +static void get_wave_count(struct amdgpu_device *adev, int queue_idx,
> + int *wave_cnt, int *vmid)
> +{
> + int pipe_idx;
> + int queue_slot;
> + unsigned int reg_val;
> +
> + /*
> + * 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.
> + */
> + *vmid = 0xFF;
> + *wave_cnt = 0;
> + pipe_idx = queue_idx / adev->gfx.mec.num_queue_per_pipe;
> + queue_slot = queue_idx % adev->gfx.mec.num_queue_per_pipe;
> + soc15_grbm_select(adev, 1, pipe_idx, queue_slot, 0);
> + reg_val = RREG32(SOC15_REG_OFFSET(GC, 0, mmSPI_CSQ_WF_ACTIVE_COUNT_0) +
> + queue_slot);
> + *wave_cnt = reg_val & SPI_CSQ_WF_ACTIVE_COUNT_0__COUNT_MASK;
> + if (*wave_cnt != 0)
> + *vmid = (RREG32_SOC15(GC, 0, mmCP_HQD_VMID) &
> + CP_HQD_VMID__VMID_MASK) >> CP_HQD_VMID__VMID__SHIFT;
> +}
> +
> +/**
> + * @kgd_gfx_v9_get_cu_occupancy: Reads relevant registers associated with
> each
> + * shader engine and aggregates the number of waves that are in fight for the
in flight
> + * process whose pasid is provided as a parameter. The process could have
> ZERO
> + * or more queues running and submitting waves to compute units.
> + *
> + * @kgd: Handle of device from which to get number of waves in flight
> + * @pasid: Identifies the process for which this query call is invoked
> + * @wave_cnt: Output parameter updated with number of waves in flight that
> + * belong to process with given pasid
> + * @max_waves_per_cu: Output parameter updated with maximum number of waves
> + * possible per Compute Unit
> + *
> + * @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 in accurate wave count. Following is a high-level sequence:
to an inaccurate
> + * 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 fligth, read CP_HQD_VMID register to obtain
> VMID
flight
> + * of the wave(s).
> + *
> + * Determine if VMID from above step maps to pasid provided as parameter.
> If
> + * it matches agrregate the wave count. That the VMID will not match
> pasid is
> + * a normal condition i.e. a device is expected to support multiple queues
> + * from multiple proceses.
> + *
> + * Reading registers referenced above involves programming GRBM
> appropriately
> + */
> +static void kgd_gfx_v9_get_cu_occupancy(struct kgd_dev *kgd, int pasid,
> + int *pasid_wave_cnt, int *max_waves_per_cu)
> +{
> + int qidx;
> + int vmid;
> + int se_idx;
> + int sh_idx;
> + int se_cnt;
> + int sh_cnt;
> + int wave_cnt;
> + int queue_map;
> + int pasid_tmp;
> + int max_queue_cnt;
> + int vmid_wave_cnt = 0;
> + struct amdgpu_device *adev;
> + DECLARE_BITMAP(cp_queue_bitmap, KGD_MAX_QUEUES);
> +
> + adev = get_amdgpu_device(kgd);
> + lock_spi_csq_mutexes(adev);
> + soc15_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.queue_bitmap,
> + KGD_MAX_QUEUES);
> + max_queue_cnt = adev->gfx.mec.num_pipe_per_mec *
> + adev->gfx.mec.num_queue_per_pipe;
> + sh_cnt = adev->gfx.config.max_sh_per_se;
> + se_cnt = adev->gfx.config.max_shader_engines;
> + for (se_idx = 0; se_idx < se_cnt; se_idx++) {
> + for (sh_idx = 0; sh_idx < sh_cnt; sh_idx++) {
> +
> + gfx_v9_0_select_se_sh(adev, se_idx, sh_idx, 0xffffffff);
> + queue_map = RREG32(SOC15_REG_OFFSET(GC, 0,
> + mmSPI_CSQ_WF_ACTIVE_STATUS));
> +
> + /*
> + * Assumption: queue map encodes following schema: four
> + * pipes per each micro-engine, with each pipe mapping
> + * eight queues. This schema is true for GFX9 devices
> + * and must be verified for newer device families
> + */
> + for (qidx = 0; qidx < max_queue_cnt; qidx++) {
> +
> + /* Skip qeueus 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, &wave_cnt, &vmid);
> + if (wave_cnt != 0) {
> + pasid_tmp =
> + RREG32(SOC15_REG_OFFSET(OSSSYS, 0,
> + mmIH_VMID_0_LUT) + vmid);
> + if (pasid_tmp == pasid)
> + vmid_wave_cnt += wave_cnt;
> + }
> + }
> + }
> + }
> +
> + gfx_v9_0_select_se_sh(adev, 0xffffffff, 0xffffffff, 0xffffffff);
> + soc15_grbm_select(adev, 0, 0, 0, 0);
> + unlock_spi_csq_mutexes(adev);
> +
> + /* Update the output parameters and return */
> + *pasid_wave_cnt = vmid_wave_cnt;
> + *max_waves_per_cu = adev->gfx.cu_info.simd_per_cu *
> + adev->gfx.cu_info.max_waves_per_simd;
> +}
> +
> const struct kfd2kgd_calls gfx_v9_kfd2kgd = {
> .program_sh_mem_settings = kgd_gfx_v9_program_sh_mem_settings,
> .set_pasid_vmid_mapping = kgd_gfx_v9_set_pasid_vmid_mapping,
> @@ -726,4 +899,5 @@ const struct kfd2kgd_calls gfx_v9_kfd2kgd = {
> .get_atc_vmid_pasid_mapping_info =
> kgd_gfx_v9_get_atc_vmid_pasid_mapping_info,
> .set_vm_context_page_table_base =
> kgd_gfx_v9_set_vm_context_page_table_base,
> + .get_cu_occupancy = kgd_gfx_v9_get_cu_occupancy,
> };
> diff --git a/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
> b/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
> index fc592f60e6a0..e37b4b9f626d 100644
> --- a/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
> +++ b/drivers/gpu/drm/amd/include/kgd_kfd_interface.h
> @@ -212,6 +212,15 @@ struct tile_config {
> * IH ring entry. This function allows the KFD ISR to get the VMID
> * from the fault status register as early as possible.
> *
> + * @get_cu_occupancy: Function pointer that returns to caller the number
> + * of wave fronts that are in flight for all of the queues of a process
> + * as identified by its pasid. It is important to note that the value
> + * returned by this function is a snapshot of current moment and cannot
> + * guarantee any minimum for the number of waves in-flight. This function
> + * is defined for devices that belong to GFX9 and later GFX families. Care
> + * must be taken in calling this function as it is not defined for devices
> + * that belong to GFX8 and below GFX families.
> + *
> * This structure contains function pointers to services that the kgd driver
> * provides to amdkfd driver.
> *
> @@ -286,6 +295,9 @@ struct kfd2kgd_calls {
> void (*set_vm_context_page_table_base)(struct kgd_dev *kgd,
> uint32_t vmid, uint64_t page_table_base);
> uint32_t (*read_vmid_from_vmfault_reg)(struct kgd_dev *kgd);
> +
> + void (*get_cu_occupancy)(struct kgd_dev *kgd, int pasid, int *wave_cnt,
> + int *max_waves_per_cu);
> };
>
> #endif /* KGD_KFD_INTERFACE_H_INCLUDED */
> --
> 2.27.0
>
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