On Tuesday, April 17, 2018 5:24:56 PM PDT Lionel Landwerlin wrote:
> v2: Add comment breaking down where the frequency values come from (Ken)
>
> Signed-off-by: Lionel Landwerlin <lionel.g.landwer...@intel.com>
> ---
> .../drivers/dri/i965/brw_performance_query.c | 49 +++++++++++++++++++
> .../drivers/dri/i965/brw_performance_query.h | 12 +++++
> 2 files changed, 61 insertions(+)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_performance_query.c
> b/src/mesa/drivers/dri/i965/brw_performance_query.c
> index 32cf96a333d..03ba4942070 100644
> --- a/src/mesa/drivers/dri/i965/brw_performance_query.c
> +++ b/src/mesa/drivers/dri/i965/brw_performance_query.c
> @@ -1341,6 +1341,54 @@ brw_is_perf_query_ready(struct gl_context *ctx,
> return false;
> }
>
> +static void
> +gen8_read_report_clock_ratios(const uint32_t *report,
> + uint64_t *slice_freq_hz,
> + uint64_t *unslice_freq_hz)
> +{
> + /* The lower 16bits of the RPT_ID field of the OA reports contains a
> + * snapshot of the bits coming from the RP_FREQ_NORMAL register and is
> + * divided this way :
> + *
> + * RPT_ID[31:25]: RP_FREQ_NORMAL[20:14] (low
> squashed_slice_clock_frequency)
> + * RPT_ID[10:9]: RP_FREQ_NORMAL[22:21] (high
> squashed_slice_clock_frequency)
> + * RPT_ID[8:0]: RP_FREQ_NORMAL[31:23] (squashed_unslice_clock_frequency)
> + *
> + * Slice/Unslice frequency values from the RP_FREQ_NORMAL register are
> + * multiples of 16.66MHz.
> + */
> +
> + uint32_t unslice_freq = report[0] & 0x1ff;
> + uint32_t slice_freq_low = (report[0] >> 25) & 0x7f;
> + uint32_t slice_freq_high = (report[0] >> 9) & 0x3;
> + uint32_t slice_freq = slice_freq_low | (slice_freq_high << 7);
> +
> + *slice_freq_hz = slice_freq * 16666000ULL;
> + *unslice_freq_hz = unslice_freq * 16666000ULL;Thanks! The comments are really helpful. I'm unclear whether the RPT_ID fields exist on BDW. Some docs seem to indicate so, but they're really a mess. I was also wondering if we wanted a bit more precision on the 16.66 approximation, but it's probably always going to be a bit off, and this seems good enough. Reviewed-by: Kenneth Graunke <kenn...@whitecape.org>
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