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

[Umesh Nerlige Ramappa]

On Wed, Jun 26, 2024 at 09:55:39AM +0200, Michal Wajdeczko wrote:
>
>
>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

Sure, I will drop the check.

>
>>
>> Reviewed-by: Matt Roper <matthew.d.roper at intel.com>
>>

Thanks,
Umesh
>>> +}
>>> 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
>>>
>>