[Intel-gfx] [PATCH v2 6/9] drm/i915: expose command stream timestamp frequency to userspace

Lionel Landwerlin lionel.g.landwerlin at intel.com
Tue Nov 7 12:07:54 UTC 2017


On 07/11/17 11:30, Ewelina Musial wrote:
> On Thu, Nov 02, 2017 at 04:29:46PM +0000, 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).
>>
>> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin 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 | 99 ++++++++++++++++++++++++++++++++
>>   include/uapi/drm/i915_drm.h              |  6 ++
>>   6 files changed, 133 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
>> index 39883cd915db..0897fd616a1f 100644
>> --- a/drivers/gpu/drm/i915/i915_debugfs.c
>> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
>> @@ -3246,6 +3246,8 @@ 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\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 e7e9e061073b..fdd23e79fb46 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -416,6 +416,9 @@ 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 6cb7cd7f9420..4e804aaeaae1 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -886,6 +886,8 @@ struct intel_device_info {
>>   	/* Slice/subslice/EU info */
>>   	struct sseu_dev_info sseu;
>>   
>> +	uint64_t 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 a2223f01ee2a..f392f28f2cfa 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 (assuming Gen8+, documentation is fuzzy...) */
>> +#define GEN8_CTC_MODE			_MMIO(0xA26C)
>> +#define  GEN8_CTC_SOURCE_PARAMETER_MASK 1
>> +#define  GEN8_CTC_SOURCE_CRYSTAL_CLOCK	0
>> +#define  GEN8_CTC_SOURCE_DIVIDE_LOGIC	1
>> +#define  GEN8_CTC_SHIFT_PARAMETER_SHIFT	1
>> +#define  GEN8_CTC_SHIFT_PARAMETER_MASK	(0x3 << GEN8_CTC_SHIFT_PARAMETER_SHIFT)
>> +
>>   /* RPC unit config (Gen8+) */
>>   #define RPC_CONFIG	    _MMIO(0x0D08)
>>   
>> @@ -8865,6 +8880,12 @@ enum skl_power_gate {
>>   #define ILK_TIMESTAMP_HI	_MMIO(0x70070)
>>   #define IVB_TIMESTAMP_CTR	_MMIO(0x44070)
>>   
>> +#define GEN8_TIMESTAMP_OVERRIDE				_MMIO(0x44074)
>> +#define  GEN8_TIMESTAMP_OVERRIDE_US_COUNTER_SHIFT		0
>> +#define  GEN8_TIMESTAMP_OVERRIDE_US_COUNTER_MASK		0x3ff
>> +#define  GEN8_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_SHIFT	12
>> +#define  GEN8_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..9b71a9b6d80e 100644
>> --- a/drivers/gpu/drm/i915/intel_device_info.c
>> +++ b/drivers/gpu/drm/i915/intel_device_info.c
>> @@ -329,6 +329,100 @@ static void broadwell_sseu_info_init(struct drm_i915_private *dev_priv)
>>   	sseu->has_eu_pg = 0;
>>   }
>>   
>> +static u64 read_timestamp_frequency_from_divide(struct drm_i915_private *dev_priv)
>> +{
>> +	u32 ts_override = I915_READ(GEN8_TIMESTAMP_OVERRIDE);
>> +	u64 base_freq, frac_freq;
>> +
>> +	base_freq = ((ts_override & GEN8_TIMESTAMP_OVERRIDE_US_COUNTER_MASK) >>
>> +		     GEN8_TIMESTAMP_OVERRIDE_US_COUNTER_SHIFT) + 1;
>> +	base_freq *= 1000000;
>> +
>> +	frac_freq = ((ts_override &
>> +		      GEN8_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_MASK) >>
>> +		     GEN8_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)
>> +{
>> +	if (INTEL_GEN(dev_priv) <= 4) {
>> +		/* PRMs say:
>> +		 *
>> +		 *     "The value in this register increments once every 16
>> +		 *      hclks." ("CLKCFG" register)
>> +		 *
>> +		 * Since dev_priv->rawclk_freq stores the value in kHz divided
>> +		 * by 4, we just need to divide it again by 4.
>> +		 */
>> +		return (dev_priv->rawclk_freq * 1000) / 4;
>> +	} else if (INTEL_GEN(dev_priv) <= 7) {
>> +		/* 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 12500000;
>> +	} else if (INTEL_GEN(dev_priv) <= 9) {
>> +		u32 ctc_reg = I915_READ(GEN8_CTC_MODE);
>> +		u64 freq = 0;
>> +
>> +		if ((ctc_reg & GEN8_CTC_SOURCE_PARAMETER_MASK) == GEN8_CTC_SOURCE_DIVIDE_LOGIC)
>> +			freq = read_timestamp_frequency_from_divide(dev_priv);
>> +		else
>> +			freq = IS_GEN9_LP(dev_priv) ? 19200000 : 24000000;
> What means those values? It looks like some 'magic numbers' here.
> Some comment or define could be helpful.

That's 19.2MHz or 24MHz.
Thanks, will add.

>> +
>> +		/* 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 & GEN8_CTC_SHIFT_PARAMETER_MASK) >>
>> +			      GEN8_CTC_SHIFT_PARAMETER_SHIFT);
>> +
>> +		return freq;
>> +	} else if (INTEL_GEN(dev_priv) <= 10) {
>> +		u32 ctc_reg = I915_READ(GEN8_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 CTC_MODE &
>> +		 * RPM_CONFIG & CTC_MODE registers. CTC_MODE tells us which
>> +		 * one we should use.
>> +		 */
>> +		if ((ctc_reg & GEN8_CTC_SOURCE_PARAMETER_MASK) == GEN8_CTC_SOURCE_DIVIDE_LOGIC) {
>> +			freq = read_timestamp_frequency_from_divide(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;
>> +			freq = crystal_clock == GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ ?
>> +				19200000 : 24000000;
> The same here.
> - Ewelina
>> +		}
>> +
>> +		/* 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 +544,9 @@ 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 +562,6 @@ 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 125bde7d9504..c3ff0d4947af 100644
>> --- a/include/uapi/drm/i915_drm.h
>> +++ b/include/uapi/drm/i915_drm.h
>> @@ -450,6 +450,12 @@ typedef struct drm_i915_irq_wait {
>>    */
>>   #define I915_PARAM_HAS_EXEC_FENCE_ARRAY  49
>>   
>> +/* 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   50
>> +
>>   typedef struct drm_i915_getparam {
>>   	__s32 param;
>>   	/*
>> -- 
>> 2.15.0
>>
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