Re: [Intel-gfx] [PATCH 06/14] drm/i915/guc/slpc: Enable SLPC and add related H2G events

["Belgaumkar, Vinay" <vinay.belgaumkar@intel.com>]

On 7/21/2021 10:38 AM, Michal Wajdeczko wrote:
> 
> 
> On 21.07.2021 18:11, Vinay Belgaumkar wrote:
>> Add methods for interacting with GuC for enabling SLPC. Enable
>> SLPC after GuC submission has been established. GuC load will
>> fail if SLPC cannot be successfully initialized. Add various
>> helper methods to set/unset the parameters for SLPC. They can
>> be set using H2G calls or directly setting bits in the shared
>> data structure.
>>
>> This patch also removes the GEM_BUG_ON from guc_submission_disable().
>> The assumption when that was added was there would be no wakerefs
>> when it would be called. However, if we fail to enable slpc, we will
> 
> s/slpc/SLPC

done.
> 
>> still be holding a wakeref.
>>
>> v2: Address several review comments, add new helpers for
>> decoding the slpc min/max frequencies. Use masks instead of hardcoded
>> constants. (Michal W)
>>
>> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
>> Signed-off-by: Sundaresan Sujaritha <sujaritha.sundaresan@intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c   | 206 ++++++++++++++++++
>>   .../gpu/drm/i915/gt/uc/intel_guc_slpc_types.h |   2 +
>>   .../gpu/drm/i915/gt/uc/intel_guc_submission.c |   4 -
>>   drivers/gpu/drm/i915/gt/uc/intel_uc.c         |  10 +
>>   4 files changed, 218 insertions(+), 4 deletions(-)
>>
>> 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 a99d727b5bf0..48db2a8f67d1 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
>> @@ -45,6 +45,40 @@ void intel_guc_slpc_init_early(struct intel_guc_slpc *slpc)
>>   	guc->slpc_selected = __guc_slpc_selected(guc);
>>   }
>>   
>> +static void slpc_mem_set_param(struct slpc_shared_data *data,
>> +				u32 id, u32 value)
>> +{
>> +	GEM_BUG_ON(id >= SLPC_MAX_OVERRIDE_PARAMETERS);
>> +	/*
>> +	 * When the flag bit is set, corresponding value will be read
>> +	 * and applied by slpc.
>> +	 */
>> +	data->override_params.bits[id >> 5] |= (1 << (id % 32));
>> +	data->override_params.values[id] = value;
>> +}
>> +
>> +static void slpc_mem_set_enabled(struct slpc_shared_data *data,
>> +				u8 enable_id, u8 disable_id)
>> +{
>> +	/*
>> +	 * Enabling a param involves setting the enable_id
>> +	 * to 1 and disable_id to 0.
>> +	 */
>> +	slpc_mem_set_param(data, enable_id, 1);
>> +	slpc_mem_set_param(data, disable_id, 0);
>> +}
>> +
>> +static void slpc_mem_set_disabled(struct slpc_shared_data *data,
>> +				u8 enable_id, u8 disable_id)
>> +{
>> +	/*
>> +	 * Disabling a param involves setting the enable_id
>> +	 * to 0 and disable_id to 1.
>> +	 */
>> +	slpc_mem_set_param(data, disable_id, 1);
>> +	slpc_mem_set_param(data, enable_id, 0);
>> +}
>> +
>>   static int slpc_shared_data_init(struct intel_guc_slpc *slpc)
>>   {
>>   	struct intel_guc *guc = slpc_to_guc(slpc);
>> @@ -63,6 +97,116 @@ static int slpc_shared_data_init(struct intel_guc_slpc *slpc)
>>   	return err;
>>   }
>>   
>> +static u32 slpc_get_state(struct intel_guc_slpc *slpc)
>> +{
>> +	struct slpc_shared_data *data;
>> +
>> +	GEM_BUG_ON(!slpc->vma);
>> +
>> +	drm_clflush_virt_range(slpc->vaddr, sizeof(u32));
>> +	data = slpc->vaddr;
>> +
>> +	return data->header.global_state;
>> +}
>> +
>> +static bool slpc_is_running(struct intel_guc_slpc *slpc)
>> +{
>> +	return (slpc_get_state(slpc) == SLPC_GLOBAL_STATE_RUNNING);
>> +}
>> +
>> +static int guc_action_slpc_query(struct intel_guc *guc, u32 offset)
>> +{
>> +	u32 request[] = {
>> +		INTEL_GUC_ACTION_SLPC_REQUEST,
>> + 		SLPC_EVENT(SLPC_EVENT_QUERY_TASK_STATE, 2),
>> +		offset,
>> +		0,
>> +	};
>> +
>> + 	return intel_guc_send(guc, request, ARRAY_SIZE(request));
>> +}
>> +
>> +static int slpc_query_task_state(struct intel_guc_slpc *slpc)
>> +{
>> +	struct intel_guc *guc = slpc_to_guc(slpc);
>> +	struct drm_i915_private *i915 = slpc_to_i915(slpc);
>> +	u32 shared_data_gtt_offset = intel_guc_ggtt_offset(guc, slpc->vma);
>> +	int ret;
>> +
>> +	ret = guc_action_slpc_query(guc, shared_data_gtt_offset);
>> +	if (ret)
>> +		drm_err(&i915->drm, "Query task state data returned (%pe)\n",
>> +				ERR_PTR(ret));
>> +
>> +	drm_clflush_virt_range(slpc->vaddr, SLPC_PAGE_SIZE_BYTES);
>> +
>> +	return ret;
>> +}
>> +
>> +static const char *slpc_state_string(struct intel_guc_slpc *slpc)
>> +{
>> +	const char *str = NULL;
>> +	u32 state = slpc_get_state(slpc);
>> +
>> +	switch (state) {
>> +	case SLPC_GLOBAL_STATE_NOT_RUNNING:
>> +		str = "not running";
>> +		break;
>> +	case SLPC_GLOBAL_STATE_INITIALIZING:
>> +		str = "initializing";
>> +		break;
>> +	case SLPC_GLOBAL_STATE_RESETTING:
>> +		str = "resetting";
>> +		break;
>> +	case SLPC_GLOBAL_STATE_RUNNING:
>> +		str = "running";
>> +		break;
>> +	case SLPC_GLOBAL_STATE_SHUTTING_DOWN:
>> +		str = "shutting down";
>> +		break;
>> +	case SLPC_GLOBAL_STATE_ERROR:
>> +		str = "error";
>> +		break;
>> +	default:
>> +		str = "unknown";
>> +		break;
>> +	}
> 
> nit: you can split as:
> 
> static const char *
> slpc_global_state_to_string(enum slpc_global_state state)
> {
> 	switch (state) {
> 	case SLPC_GLOBAL_STATE_NOT_RUNNING:
> 		return "not running";
> 	case SLPC_GLOBAL_STATE_INITIALIZING:
> 		return "initializing";
> 	...
> 
> and
> 
> static const char *slpc_get_state_string(struct intel_guc_slpc *slpc)
> {
> 	return slpc_global_state_to_string(slpc_get_state(slpc));
> }

Ok, done.

> 
> 
>> +
>> +	return str;
>> +}
>> +
>> +static int guc_action_slpc_reset(struct intel_guc *guc, u32 offset)
>> +{
>> +	u32 request[] = {
>> +		INTEL_GUC_ACTION_SLPC_REQUEST,
>> +		SLPC_EVENT(SLPC_EVENT_RESET, 2),
>> +		offset,
>> +		0,
>> +	};
>> +
>> + 	return intel_guc_send(guc, request, ARRAY_SIZE(request));
> 
> don't know details of H2G request/response message (btw, maybe you can
> include something in ABI.h) but be aware that guc_send() might return
> non-zero DATA0 so if you don't expect it, return -EPROTO
> 
>> +}
>> +
>> +static int slpc_reset(struct intel_guc_slpc *slpc)
>> +{
>> +	struct drm_i915_private *i915 = slpc_to_i915(slpc);
>> +	struct intel_guc *guc = slpc_to_guc(slpc);
>> +	u32 shared_data_gtt_offset = intel_guc_ggtt_offset(guc, slpc->vma);
> 
> just "offset" ?

yup.

> 
>> +	int ret;
>> +
>> +	ret = guc_action_slpc_reset(guc, shared_data_gtt_offset);
>> +
>> +	if (!ret) {
> 
> if (unlikely(ret < 0))
> 	return ret;
> 
>> +		if (wait_for(slpc_is_running(slpc), SLPC_RESET_TIMEOUT_MS)) {
>> +			drm_err(&i915->drm, "SLPC not enabled! State = %s\n",
>> +				  slpc_state_string(slpc));
>> +			return -EIO;
>> +		}
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>   int intel_guc_slpc_init(struct intel_guc_slpc *slpc)
>>   {
>>   	GEM_BUG_ON(slpc->vma);
>> @@ -70,6 +214,30 @@ int intel_guc_slpc_init(struct intel_guc_slpc *slpc)
>>   	return slpc_shared_data_init(slpc);
>>   }
>>   
>> +u32 slpc_decode_min_freq(struct intel_guc_slpc *slpc)
>> +{
>> +	struct slpc_shared_data *data = slpc->vaddr;
>> +
>> +	GEM_BUG_ON(!slpc->vma);
>> +
>> +	return	DIV_ROUND_CLOSEST(
>> +		REG_FIELD_GET(SLPC_MIN_UNSLICE_FREQ_MASK,
>> +			data->task_state_data.freq) *
>> +		GT_FREQUENCY_MULTIPLIER, GEN9_FREQ_SCALER);
>> +}
>> +
>> +u32 slpc_decode_max_freq(struct intel_guc_slpc *slpc)
>> +{
>> +	struct slpc_shared_data *data = slpc->vaddr;
>> +
>> +	GEM_BUG_ON(!slpc->vma);
>> +
>> +	return	DIV_ROUND_CLOSEST(
>> +		REG_FIELD_GET(SLPC_MAX_UNSLICE_FREQ_MASK,
>> +			data->task_state_data.freq) *
>> +		GT_FREQUENCY_MULTIPLIER, GEN9_FREQ_SCALER);
>> +}
>> +
>>   /*
>>    * intel_guc_slpc_enable() - Start SLPC
>>    * @slpc: pointer to intel_guc_slpc.
>> @@ -85,6 +253,44 @@ int intel_guc_slpc_init(struct intel_guc_slpc *slpc)
>>    */
>>   int intel_guc_slpc_enable(struct intel_guc_slpc *slpc)
>>   {
>> +	struct drm_i915_private *i915 = slpc_to_i915(slpc);
>> +	struct slpc_shared_data *data;
>> +	int ret;
>> +
>> +	GEM_BUG_ON(!slpc->vma);
>> +
>> +	memset(slpc->vaddr, 0, sizeof(struct slpc_shared_data));
>> +
>> +	data = slpc->vaddr;
>> +	data->header.size = sizeof(struct slpc_shared_data);
>> +
>> +	/* Enable only GTPERF task, disable others */
>> +	slpc_mem_set_enabled(data, SLPC_PARAM_TASK_ENABLE_GTPERF,
>> +				SLPC_PARAM_TASK_DISABLE_GTPERF);
>> +
>> +	slpc_mem_set_disabled(data, SLPC_PARAM_TASK_ENABLE_BALANCER,
>> +				SLPC_PARAM_TASK_DISABLE_BALANCER);
>> +
>> +	slpc_mem_set_disabled(data, SLPC_PARAM_TASK_ENABLE_DCC,
>> +				SLPC_PARAM_TASK_DISABLE_DCC);
>> +
>> +	ret = slpc_reset(slpc);
>> +	if (ret) {
> 
> if (unlikely(ret < 0)) ?

ok.

> 
>> +		drm_err(&i915->drm, "SLPC Reset event returned (%pe)\n",
>> +				ERR_PTR(ret));
>> +		return ret;
>> +	}
>> +
>> +	drm_info(&i915->drm, "SLPC state: %s\n", slpc_state_string(slpc));
> 
> do we expect here something else than "running" ?
No, changed this to enabled instead, fixes the ordering below as well.

> 
>> +
>> +	slpc_query_task_state(slpc);
>> +
>> +	/* min and max frequency limits being used by SLPC */
>> +	drm_info(&i915->drm, "SLPC min freq: %u Mhz, max is %u Mhz\n",
>> +			slpc_decode_min_freq(slpc),
>> +			slpc_decode_max_freq(slpc));
>> +
>> +
>>   	return 0;
>>   }
>>   
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h
>> index 214a449e78f2..c417992b1346 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h
>> @@ -9,6 +9,8 @@
>>   #include <linux/types.h>
>>   #include "abi/guc_actions_slpc_abi.h"
>>   
>> +#define SLPC_RESET_TIMEOUT_MS 5
>> +
>>   struct intel_guc_slpc {
>>   
>>   	struct i915_vma *vma;
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>> index 9083bd4adb22..142e44dc5bf1 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
>> @@ -2506,10 +2506,6 @@ void intel_guc_submission_enable(struct intel_guc *guc)
>>   
>>   void intel_guc_submission_disable(struct intel_guc *guc)
>>   {
>> -	struct intel_gt *gt = guc_to_gt(guc);
>> -
>> -	GEM_BUG_ON(gt->awake); /* GT should be parked first */
>> ->  	/* Note: By the time we're here, GuC may have already been reset */
>>   }
>>   
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
>> index e6bd9406c7b2..3f2aa83c5c45 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
>> @@ -506,6 +506,14 @@ static int __uc_init_hw(struct intel_uc *uc)
>>   		 "submission",
>>   		 enableddisabled(intel_uc_uses_guc_submission(uc)));
>>   
>> +	if (intel_uc_uses_guc_slpc(uc)) {
>> +		ret = intel_guc_slpc_enable(&guc->slpc);
>> +		if (ret)
>> +			goto err_submission;
>> +		drm_info(&i915->drm, "GuC SLPC %s\n",
>> +			 enableddisabled(intel_uc_uses_guc_slpc(uc)));
> 
> there will be (in this order):
> 
> 	"GuC submission enabled\n"
> 	"SLPC state: running\n"
> 	"SLPC min freq: %u Mhz, max is %u Mhz\n"
> 	"GuC SLPC enabled\n"
> 
> is this what you wanted ?

Fixed now.
Thanks,
Vinay.
> 
> Michal
> 
>> +	}
>> +
>>   	if (intel_uc_uses_huc(uc)) {
>>   		drm_info(&i915->drm, "%s firmware %s version %u.%u %s:%s\n",
>>   			 intel_uc_fw_type_repr(INTEL_UC_FW_TYPE_HUC),
>> @@ -520,6 +528,8 @@ static int __uc_init_hw(struct intel_uc *uc)
>>   	/*
>>   	 * We've failed to load the firmware :(
>>   	 */
>> +err_submission:
>> +	intel_guc_submission_disable(guc);
>>   err_log_capture:
>>   	__uc_capture_load_err_log(uc);
>>   err_out:
>>
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