[PATCH] drm/xe: Get hwe domain specific FW to read RING_TIMESTAMP

[Michal Wajdeczko]

On 26.06.2024 00:13, Matt Roper wrote:
> On Tue, Jun 25, 2024 at 11:38:42PM +0800, Umesh Nerlige Ramappa wrote:
>> Per client engine utilization uses RING_TIMESTAMP to return drm-total-cycles to
>> the user. Current code uses XE_FW_GT to read this register on the first
>> available engine in a GT. When testing on DG2, it is observed that this value is
>> 0 when running test on some engines. To resolve that, get the hwe domain
>> specific FW for reading the engine timestamp.
>>
>> v2:
>> - update commit message
>> - use domain specific FW (Matt)
>>
>> Fixes: 188ced1e0ff8 ("drm/xe/client: Print runtime to fdinfo")
>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>> ---
>>  drivers/gpu/drm/xe/xe_drm_client.c | 7 +++++--
>>  drivers/gpu/drm/xe/xe_hw_engine.c  | 5 +++++
>>  drivers/gpu/drm/xe/xe_hw_engine.h  | 1 +
>>  3 files changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_drm_client.c b/drivers/gpu/drm/xe/xe_drm_client.c
>> index 4a19b771e3a0..886965e81465 100644
>> --- a/drivers/gpu/drm/xe/xe_drm_client.c
>> +++ b/drivers/gpu/drm/xe/xe_drm_client.c
>> @@ -260,13 +260,16 @@ static void show_run_ticks(struct drm_printer *p, struct drm_file *file)
>>  
>>  	/* Get the total GPU cycles */
>>  	for_each_gt(gt, xe, gt_id) {
>> +		enum xe_force_wake_domains fw;
>> +
>>  		hwe = xe_gt_any_hw_engine(gt);
>>  		if (!hwe)
>>  			continue;
>>  
>> -		xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
>> +		fw = xe_hw_engine_to_fw_domain(hwe);
>> +		xe_force_wake_get(gt_to_fw(gt), fw);
>>  		gpu_timestamp = xe_hw_engine_read_timestamp(hwe);
>> -		xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
>> +		xe_force_wake_put(gt_to_fw(gt), fw);
>>  		break;
>>  	}
>>  
>> diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
>> index 78b50d3a6501..97f43ba3a00f 100644
>> --- a/drivers/gpu/drm/xe/xe_hw_engine.c
>> +++ b/drivers/gpu/drm/xe/xe_hw_engine.c
>> @@ -1130,3 +1130,8 @@ u64 xe_hw_engine_read_timestamp(struct xe_hw_engine *hwe)
>>  {
>>  	return xe_mmio_read64_2x32(hwe->gt, RING_TIMESTAMP(hwe->mmio_base));
>>  }
>> +
>> +enum xe_force_wake_domains xe_hw_engine_to_fw_domain(struct xe_hw_engine *hwe)
>> +{
>> +	return hwe ? engine_infos[hwe->engine_id].domain : 0;
> 
> Not sure if we really need the ternary operator here since it wouldn't
> really make sense to call this function with a NULL hwe.  But it doesn't
> hurt anything either, so

except that now function returns value 0 which is not a valid enumerator
from enum xe_force_wake_domains, so I would suggest to assume that hwe
must be always != NULL and remove this trouble maker ternary operator

> 
> Reviewed-by: Matt Roper <matthew.d.roper at intel.com>
> 
>> +}
>> diff --git a/drivers/gpu/drm/xe/xe_hw_engine.h b/drivers/gpu/drm/xe/xe_hw_engine.h
>> index 7f2d27c0ba1a..900c8c991430 100644
>> --- a/drivers/gpu/drm/xe/xe_hw_engine.h
>> +++ b/drivers/gpu/drm/xe/xe_hw_engine.h
>> @@ -69,5 +69,6 @@ static inline bool xe_hw_engine_is_valid(struct xe_hw_engine *hwe)
>>  
>>  const char *xe_hw_engine_class_to_str(enum xe_engine_class class);
>>  u64 xe_hw_engine_read_timestamp(struct xe_hw_engine *hwe);
>> +enum xe_force_wake_domains xe_hw_engine_to_fw_domain(struct xe_hw_engine *hwe);
>>  
>>  #endif
>> -- 
>> 2.34.1
>>
>