On Fri, Oct 16, 2026 at 6:11 AM Victor Zhao <[email protected]> wrote:
>
> [why]
> GFX12.1 VF timestamp queries need a SMUIO Golden TSC sample, but
> direct SMUIO MMIO access is restricted on VF.
>
> [how]
> Read the consecutive SMUIO Golden TSC upper and lower registers with
> amdgpu_mes_rreg64() on GFX12.1 VF. Swap the returned dwords to
> reconstruct the counter value.
>
> v4: use SMUIO Golden TSC for GFX12.1 VF timestamp queries
>
> Signed-off-by: Victor Zhao <[email protected]>
> ---
> drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c
> b/drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c
> index d6f70d33201a0..93c8f8e449bf4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v12_1.c
> @@ -37,6 +37,7 @@
>
> #include "gc/gc_12_1_0_offset.h"
> #include "gc/gc_12_1_0_sh_mask.h"
> +#include "smuio/smuio_15_0_0_offset.h"
> #include "soc24_enum.h"
> #include "ivsrcid/gfx/irqsrcs_gfx_12_1_0.h"
>
> @@ -3168,10 +3169,35 @@ static int gfx_v12_1_wait_for_idle(struct
> amdgpu_ip_block *ip_block)
> return -ETIMEDOUT;
> }
>
> +static uint64_t gfx_v12_1_get_smuio_gpu_clock_counter(struct amdgpu_device
> *adev)
> +{
> + uint64_t clock = 0;
> + uint32_t reg;
> +
> + if (!down_read_trylock(&adev->reset_domain->sem))
> + return 0;
> + if (amdgpu_device_skip_hw_access(adev) ||
> + !adev->mes.ring[0].sched.ready)
> + goto unlock_reset;
> +
> + reg = SOC15_REG_OFFSET(SMUIO, 0, regGOLDEN_TSC_COUNT_UPPER);
> + if (amdgpu_mes_rreg64(adev, reg, 0, &clock))
I don't see this function in the current tree. Are you missing a patch?
Alex
> + goto unlock_reset;
> +
> + clock = (clock << 32) | (clock >> 32);
> +
> +unlock_reset:
> + up_read(&adev->reset_domain->sem);
> + return clock;
> +}
> +
> static uint64_t gfx_v12_1_get_gpu_clock_counter(struct amdgpu_device *adev)
> {
> uint64_t clock = 0;
>
> + if (amdgpu_sriov_vf(adev))
> + return gfx_v12_1_get_smuio_gpu_clock_counter(adev);
> +
> if (adev->smuio.funcs &&
> adev->smuio.funcs->get_gpu_clock_counter)
> clock = adev->smuio.funcs->get_gpu_clock_counter(adev);
> --
> 2.50.1
>
