On Wed, Sep 07, 2022 at 01:30:41PM -0700, Lucas De Marchi wrote:
> Continue converting the driver to the convention of last version first,
> extending it to the future platforms. Now, any GRAPHICS_VER >= 11 will
> be handled by the first branch.
>
> With the new ranges it's easier to see what platform a branch started to
> be taken. Besides the >= 11 change, the branch taken for GRAPHICS_VER == 10
> is also different, but currently there is no such platform in i915.
>
> Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
> Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
> ---
> .../gpu/drm/i915/gt/intel_gt_clock_utils.c | 77 +++++++++----------
> 1 file changed, 37 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c b/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
> index d5d1b04dbcad..93608c9349fd 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
> @@ -78,77 +78,74 @@ static u32 read_clock_frequency(struct intel_uncore *uncore)
> u32 f19_2_mhz = 19200000;
> u32 f24_mhz = 24000000;
>
> - if (GRAPHICS_VER(uncore->i915) <= 4) {
> - /*
> - * PRMs say:
> - *
> - * "The value in this register increments once every 16
> - * hclks." (through the “Clocking Configuration”
> - * (“CLKCFG”) MCHBAR register)
> - */
> - return RUNTIME_INFO(uncore->i915)->rawclk_freq * 1000 / 16;
> - } else if (GRAPHICS_VER(uncore->i915) <= 8) {
> - /*
> - * PRMs say:
> - *
> - * "The PCU TSC counts 10ns increments; this timestamp
> - * reflects bits 38:3 of the TSC (i.e. 80ns granularity,
> - * rolling over every 1.5 hours).
> - */
> - return f12_5_mhz;
> - } else if (GRAPHICS_VER(uncore->i915) <= 9) {
Is there a good reason each of these branches isn't just its own function?
> + if (GRAPHICS_VER(uncore->i915) >= 11) {
> u32 ctc_reg = intel_uncore_read(uncore, CTC_MODE);
> u32 freq = 0;
>
> + /*
> + * First figure out the reference frequency. There are 2 ways
> + * we can compute the frequency, either through the
> + * TIMESTAMP_OVERRIDE register or through RPM_CONFIG. CTC_MODE
> + * tells us which one we should use.
> + */
> if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) {
> freq = read_reference_ts_freq(uncore);
> } else {
> - freq = IS_GEN9_LP(uncore->i915) ? f19_2_mhz : f24_mhz;
> + u32 c0 = intel_uncore_read(uncore, RPM_CONFIG0);
> +
> + if (GRAPHICS_VER(uncore->i915) >= 11)
> + freq = gen11_get_crystal_clock_freq(uncore, c0);
> + else
> + freq = gen9_get_crystal_clock_freq(uncore, c0);
>
> /*
> * Now figure out how the command stream's timestamp
> * register increments from this frequency (it might
> * increment only every few clock cycle).
> */
> - freq >>= 3 - ((ctc_reg & CTC_SHIFT_PARAMETER_MASK) >>
> - CTC_SHIFT_PARAMETER_SHIFT);
> + freq >>= 3 - ((c0 & GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK) >>
> + GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT);
> }
>
> return freq;
> - } else if (GRAPHICS_VER(uncore->i915) <= 12) {
> + } else if (GRAPHICS_VER(uncore->i915) >= 9) {
> u32 ctc_reg = intel_uncore_read(uncore, CTC_MODE);
> u32 freq = 0;
>
> - /*
> - * First figure out the reference frequency. There are 2 ways
> - * we can compute the frequency, either through the
> - * TIMESTAMP_OVERRIDE register or through RPM_CONFIG. CTC_MODE
> - * tells us which one we should use.
> - */
> if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) {
> freq = read_reference_ts_freq(uncore);
> } else {
> - u32 c0 = intel_uncore_read(uncore, RPM_CONFIG0);
> -
> - if (GRAPHICS_VER(uncore->i915) >= 11)
> - freq = gen11_get_crystal_clock_freq(uncore, c0);
> - else
> - freq = gen9_get_crystal_clock_freq(uncore, c0);
> + freq = IS_GEN9_LP(uncore->i915) ? f19_2_mhz : f24_mhz;
>
> /*
> * Now figure out how the command stream's timestamp
> * register increments from this frequency (it might
> * increment only every few clock cycle).
> */
> - freq >>= 3 - ((c0 & GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK) >>
> - GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT);
> + freq >>= 3 - ((ctc_reg & CTC_SHIFT_PARAMETER_MASK) >>
> + CTC_SHIFT_PARAMETER_SHIFT);
> }
>
> return freq;
> + } else if (GRAPHICS_VER(uncore->i915) >= 5) {
> + /*
> + * PRMs say:
> + *
> + * "The PCU TSC counts 10ns increments; this timestamp
> + * reflects bits 38:3 of the TSC (i.e. 80ns granularity,
> + * rolling over every 1.5 hours).
> + */
> + return f12_5_mhz;
> + } else {
> + /*
> + * PRMs say:
> + *
> + * "The value in this register increments once every 16
> + * hclks." (through the “Clocking Configuration”
> + * (“CLKCFG”) MCHBAR register)
> + */
> + return RUNTIME_INFO(uncore->i915)->rawclk_freq * 1000 / 16;
> }
> -
> - MISSING_CASE("Unknown gen, unable to read command streamer timestamp frequency\n");
> - return 0;
> }
>
> void intel_gt_init_clock_frequency(struct intel_gt *gt)
> --
> 2.37.2
--
Ville Syrjälä
Intel
