[PATCH 07/14] drm/i915/guc/slpc: Add methods to set min/max frequency

[Michal Wajdeczko]

On 21.07.2021 18:11, Vinay Belgaumkar wrote:
> Add param set h2g helpers to set the min and max frequencies
> for use by SLPC.
> 
> v2: Address review comments (Michal W)
> 
> Signed-off-by: Sundaresan Sujaritha <sujaritha.sundaresan at intel.com>
> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 84 +++++++++++++++++++++
>  drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h |  2 +
>  2 files changed, 86 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
> index 48db2a8f67d1..b40c39ba4049 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
> @@ -109,6 +109,18 @@ static u32 slpc_get_state(struct intel_guc_slpc *slpc)
>  	return data->header.global_state;
>  }
>  
> +static int guc_action_slpc_set_param(struct intel_guc *guc, u8 id, u32 value)
> +{
> +	u32 request[] = {
> +		INTEL_GUC_ACTION_SLPC_REQUEST,
> + 		SLPC_EVENT(SLPC_EVENT_PARAMETER_SET, 2),
> +		id,
> +		value,
> +	};
> +
> + 	return intel_guc_send(guc, request, ARRAY_SIZE(request));

beware of possible non-zero data0 returned by guc_send()

> +}
> +
>  static bool slpc_is_running(struct intel_guc_slpc *slpc)
>  {
>  	return (slpc_get_state(slpc) == SLPC_GLOBAL_STATE_RUNNING);
> @@ -143,6 +155,15 @@ static int slpc_query_task_state(struct intel_guc_slpc *slpc)
>  	return ret;
>  }
>  
> +static int slpc_set_param(struct intel_guc_slpc *slpc, u8 id, u32 value)
> +{
> +	struct intel_guc *guc = slpc_to_guc(slpc);
> +
> +	GEM_BUG_ON(id >= SLPC_MAX_PARAM);
> +
> +	return guc_action_slpc_set_param(guc, id, value);
> +}
> +
>  static const char *slpc_state_string(struct intel_guc_slpc *slpc)
>  {
>  	const char *str = NULL;
> @@ -238,6 +259,69 @@ u32 slpc_decode_max_freq(struct intel_guc_slpc *slpc)
>  		GT_FREQUENCY_MULTIPLIER, GEN9_FREQ_SCALER);
>  }
>  
> +/**
> + * intel_guc_slpc_set_max_freq() - Set max frequency limit for SLPC.
> + * @slpc: pointer to intel_guc_slpc.
> + * @val: frequency (MHz)
> + *
> + * This function will invoke GuC SLPC action to update the max frequency
> + * limit for unslice.
> + *
> + * Return: 0 on success, non-zero error code on failure.
> + */
> +int intel_guc_slpc_set_max_freq(struct intel_guc_slpc *slpc, u32 val)
> +{
> +	int ret;
> +	struct drm_i915_private *i915 = slpc_to_i915(slpc);
> +	intel_wakeref_t wakeref;

nit: move "ret" as last

> +
> +	with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
> +		ret = slpc_set_param(slpc,
> +			       SLPC_PARAM_GLOBAL_MAX_GT_UNSLICE_FREQ_MHZ,
> +			       val);
> +		if (ret) {
> +			drm_err(&i915->drm,
> +				"Set max frequency unslice returned (%pe)\n", ERR_PTR(ret));
> +			/* Return standardized err code for sysfs */
> +			ret = -EIO;

maybe caller (hook in sysfs) can sanitize this error ?

Michal

> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +/**
> + * intel_guc_slpc_set_min_freq() - Set min frequency limit for SLPC.
> + * @slpc: pointer to intel_guc_slpc.
> + * @val: frequency (MHz)
> + *
> + * This function will invoke GuC SLPC action to update the min unslice
> + * frequency.
> + *
> + * Return: 0 on success, non-zero error code on failure.
> + */
> +int intel_guc_slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 val)
> +{
> +	int ret;
> +	struct intel_guc *guc = slpc_to_guc(slpc);
> +	struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
> +	intel_wakeref_t wakeref;
> +
> +	with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
> +		ret = slpc_set_param(slpc,
> +			       SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
> +			       val);
> +		if (ret) {
> +			drm_err(&i915->drm,
> +				"Set min frequency for unslice returned (%pe)\n", ERR_PTR(ret));
> +			/* Return standardized err code for sysfs */
> +			ret = -EIO;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
>  /*
>   * intel_guc_slpc_enable() - Start SLPC
>   * @slpc: pointer to intel_guc_slpc.
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
> index f02249ff5f1b..3a1a7eaafc12 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
> @@ -30,5 +30,7 @@ void intel_guc_slpc_init_early(struct intel_guc_slpc *slpc);
>  int intel_guc_slpc_init(struct intel_guc_slpc *slpc);
>  int intel_guc_slpc_enable(struct intel_guc_slpc *slpc);
>  void intel_guc_slpc_fini(struct intel_guc_slpc *slpc);
> +int intel_guc_slpc_set_max_freq(struct intel_guc_slpc *slpc, u32 val);
> +int intel_guc_slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 val);
>  
>  #endif
>