[Intel-gfx] [PATCH 6/7] drm/i915: expose command stream timestamp frequency to userspace

Sagar Arun Kamble sagar.a.kamble at intel.com
Mon Nov 13 09:15:35 UTC 2017



On 11/11/2017 12:38 AM, Lionel Landwerlin wrote:
> We use to have this fixed per generation, but starting with CNL userspace
> cannot tell just off the PCI ID. Let's make this information available. This
> is particularly useful for performance monitoring where much of the
> normalization work is done using those timestamps (this include pipeline
> statistics in both GL & Vulkan as well as OA reports).
>
> v2: Use variables for 24MHz/19.2MHz values (Ewelina)
>      Renamed function & coding style (Sagar)
>
> v3: Fix frequency read on Broadwell (Sagar)
>      Fix missing divide by 4 on <= gen4 (Sagar)
>
> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> Tested-by: Rafael Antognolli <rafael.antognolli at intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_debugfs.c      |   2 +
>   drivers/gpu/drm/i915/i915_drv.c          |   3 +
>   drivers/gpu/drm/i915/i915_drv.h          |   2 +
>   drivers/gpu/drm/i915/i915_reg.h          |  21 ++++++
>   drivers/gpu/drm/i915/intel_device_info.c | 107 +++++++++++++++++++++++++++++++
>   include/uapi/drm/i915_drm.h              |   6 ++
>   6 files changed, 141 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 533ba096b9a6..57485f29d7c9 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -3245,6 +3245,8 @@ static int i915_engine_info(struct seq_file *m, void *unused)
>   		   yesno(dev_priv->gt.awake));
>   	seq_printf(m, "Global active requests: %d\n",
>   		   dev_priv->gt.active_requests);
> +	seq_printf(m, "CS timestamp frequency: %llu Hz\n",
> +		   dev_priv->info.cs_timestamp_frequency);
>   
>   	p = drm_seq_file_printer(m);
>   	for_each_engine(engine, dev_priv, id)
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index d97fe9c9439a..dbd04d5f75ee 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -419,6 +419,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
>   		if (!value)
>   			return -ENODEV;
>   		break;
> +	case I915_PARAM_CS_TIMESTAMP_FREQUENCY:
> +		value = INTEL_INFO(dev_priv)->cs_timestamp_frequency;
> +		break;
>   	default:
>   		DRM_DEBUG("Unknown parameter %d\n", param->param);
>   		return -EINVAL;
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 9f26c34e0e52..ebc49ca58eb7 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -885,6 +885,8 @@ struct intel_device_info {
>   	/* Slice/subslice/EU info */
>   	struct sseu_dev_info sseu;
>   
> +	u64 cs_timestamp_frequency;
> +
>   	struct color_luts {
>   		u16 degamma_lut_size;
>   		u16 gamma_lut_size;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 7aa7dc0c336b..ec9faa11e305 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -1119,9 +1119,24 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
>   
>   /* RPM unit config (Gen8+) */
>   #define RPM_CONFIG0	    _MMIO(0x0D00)
> +#define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT	3
> +#define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK	(1 << GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT)
> +#define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ	0
> +#define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ	1
> +#define  GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT	1
> +#define  GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK	(0x3 << GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT)
> +
>   #define RPM_CONFIG1	    _MMIO(0x0D04)
>   #define  GEN10_GT_NOA_ENABLE  (1 << 9)
>   
> +/* GPM unit config (Gen9+) */
> +#define CTC_MODE			_MMIO(0xA26C)
> +#define  CTC_SOURCE_PARAMETER_MASK 1
> +#define  CTC_SOURCE_CRYSTAL_CLOCK	0
> +#define  CTC_SOURCE_DIVIDE_LOGIC	1
> +#define  CTC_SHIFT_PARAMETER_SHIFT	1
> +#define  CTC_SHIFT_PARAMETER_MASK	(0x3 << CTC_SHIFT_PARAMETER_SHIFT)
> +
>   /* RCP unit config (Gen8+) */
>   #define RCP_CONFIG	    _MMIO(0x0D08)
>   
> @@ -8866,6 +8881,12 @@ enum skl_power_gate {
>   #define ILK_TIMESTAMP_HI	_MMIO(0x70070)
>   #define IVB_TIMESTAMP_CTR	_MMIO(0x44070)
>   
> +#define GEN9_TIMESTAMP_OVERRIDE				_MMIO(0x44074)
> +#define  GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_SHIFT	0
> +#define  GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_MASK	0x3ff
> +#define  GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_SHIFT	12
> +#define  GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_MASK	(0xf << 12)
> +
>   #define _PIPE_FRMTMSTMP_A		0x70048
>   #define PIPE_FRMTMSTMP(pipe)		\
>   			_MMIO_PIPE2(pipe, _PIPE_FRMTMSTMP_A)
> diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
> index db03d179fc85..78bf7374fbdd 100644
> --- a/drivers/gpu/drm/i915/intel_device_info.c
> +++ b/drivers/gpu/drm/i915/intel_device_info.c
> @@ -329,6 +329,108 @@ static void broadwell_sseu_info_init(struct drm_i915_private *dev_priv)
>   	sseu->has_eu_pg = 0;
>   }
>   
> +static u64 read_reference_ts_freq(struct drm_i915_private *dev_priv)
> +{
> +	u32 ts_override = I915_READ(GEN9_TIMESTAMP_OVERRIDE);
> +	u64 base_freq, frac_freq;
> +
> +	base_freq = ((ts_override & GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_MASK) >>
> +		     GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_SHIFT) + 1;
> +	base_freq *= 1000000;
> +
> +	frac_freq = ((ts_override &
> +		      GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_MASK) >>
> +		     GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_SHIFT);
> +	if (frac_freq != 0)
> +		frac_freq = 1000000 / (frac_freq + 1);
> +
> +	return base_freq + frac_freq;
> +}
> +
> +static u64 read_timestamp_frequency(struct drm_i915_private *dev_priv)
> +{
> +	u64 f12_5_mhz = 12500000;
> +	u64 f19_2_mhz = 19200000;
> +	u64 f24_mhz = 24000000;
> +
> +	if (INTEL_GEN(dev_priv) <= 4) {
> +		/* PRMs say:
> +		 *
> +		 *     "The value in this register increments once every 16
> +		 *      hclks." (through the “Clocking Configuration”
> +		 *      (“CLKCFG”) MCHBAR register)
> +		 */
> +		return (dev_priv->rawclk_freq * 1000) / 16;
> +	} else if (INTEL_GEN(dev_priv) <= 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 (INTEL_GEN(dev_priv) <= 9) {
> +		u32 ctc_reg = I915_READ(CTC_MODE);
> +		u64 freq = 0;
> +
> +		if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) {
> +			freq = read_reference_ts_freq(dev_priv);
> +		} else {
> +			freq = IS_GEN9_LP(dev_priv) ? 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 - ((ctc_reg & CTC_SHIFT_PARAMETER_MASK) >>
> +				      CTC_SHIFT_PARAMETER_SHIFT);
> +		}
> +
> +		return freq;
> +	} else if (INTEL_GEN(dev_priv) <= 10) {
> +		u32 ctc_reg = I915_READ(CTC_MODE);
> +		u64 freq = 0;
> +		u32 rpm_config_reg = 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(dev_priv);
> +		} else {
> +			u32 crystal_clock;
> +
> +			rpm_config_reg = I915_READ(RPM_CONFIG0);
> +			crystal_clock = (rpm_config_reg &
> +					 GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
> +				GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
> +			switch (crystal_clock) {
> +			case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
> +				freq = f19_2_mhz;
> +				break;
> +			case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
> +				freq = f24_mhz;
> +				break;
> +			}
> +		}
> +
> +		/* Now figure out how the command stream's timestamp register
> +		 * increments from this frequency (it might increment only
> +		 * every few clock cycle).
> +		 */
> +		freq >>= 3 - ((rpm_config_reg &
> +			       GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK) >>
> +			      GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT);
> +
> +		return freq;
> +	}
> +
> +	DRM_ERROR("Unknown gen, unable to compute command stream timestamp frequency\n");
> +	return 0;
> +}
> +
>   /*
>    * Determine various intel_device_info fields at runtime.
>    *
> @@ -450,6 +552,9 @@ void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
>   	else if (INTEL_GEN(dev_priv) >= 10)
>   		gen10_sseu_info_init(dev_priv);
>   
> +	/* Initialize command stream timestamp frequency */
> +	info->cs_timestamp_frequency = read_timestamp_frequency(dev_priv);
> +
>   	DRM_DEBUG_DRIVER("slice mask: %04x\n", info->sseu.slice_mask);
>   	DRM_DEBUG_DRIVER("slice total: %u\n", hweight8(info->sseu.slice_mask));
>   	DRM_DEBUG_DRIVER("subslice total: %u\n",
> @@ -465,4 +570,6 @@ void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
>   			 info->sseu.has_subslice_pg ? "y" : "n");
>   	DRM_DEBUG_DRIVER("has EU power gating: %s\n",
>   			 info->sseu.has_eu_pg ? "y" : "n");
> +	DRM_DEBUG_DRIVER("CS timestamp frequency: %llu\n",
> +			 info->cs_timestamp_frequency);
>   }
> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index 6c02ced663f8..b57985929553 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -481,6 +481,12 @@ typedef struct drm_i915_irq_wait {
>    */
>   #define I915_PARAM_HAS_CONTEXT_ISOLATION 50
>   
> +/* Frequency of the command streamer timestamps given by the *_TIMESTAMP
> + * registers. This used to be fixed per platform but from CNL onwards, this
> + * might vary depending on the parts.
> + */
> +#define I915_PARAM_CS_TIMESTAMP_FREQUENCY 51
> +
>   typedef struct drm_i915_getparam {
>   	__s32 param;
>   	/*



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