[Intel-gfx] [PATCH v2] drm/i915: Introduce struct class_instance for engines across the uAPI

[Ye, Tony]

On 4/12/2019 8:10 PM, Tvrtko Ursulin wrote:
>
> On 12/04/2019 08:14, Chris Wilson wrote:
>> SSEU reprogramming of the context introduced the notion of engine class
>> and instance for a forwards compatible method of describing any engine
>> beyond the old execbuf interface. We wish to adopt this class:instance
>> description for more interfaces, so pull it out into a separate type for
>> userspace convenience.
>>
>> References: e46c2e99f600 ("drm/i915: Expose RPCS (SSEU) configuration 
>> to userspace (Gen11 only)")
>> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
>> Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin at intel.com>
>> Cc: Tony Ye <tony.ye at intel.com>
>> Cc: Andi Shyti <andi at etezian.org>
>> ---
>> Drop the union foible. It's only going to hinder a decision ;)
>> -Chris
>> ---
>>   drivers/gpu/drm/i915/i915_gem_context.c |  8 ++++----
>>   include/uapi/drm/i915_drm.h             | 16 ++++++++++++++--
>>   2 files changed, 18 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c 
>> b/drivers/gpu/drm/i915/i915_gem_context.c
>> index 7fc34ab6df87..dd728b26b5aa 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_context.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
>> @@ -1386,8 +1386,8 @@ static int set_sseu(struct i915_gem_context *ctx,
>>           return -EINVAL;
>>         engine = intel_engine_lookup_user(i915,
>> -                      user_sseu.engine_class,
>> -                      user_sseu.engine_instance);
>> +                      user_sseu.engine.engine_class,
>> +                      user_sseu.engine.engine_instance);
>>       if (!engine)
>>           return -EINVAL;
>>   @@ -1626,8 +1626,8 @@ static int get_sseu(struct i915_gem_context 
>> *ctx,
>>           return -EINVAL;
>>         engine = intel_engine_lookup_user(ctx->i915,
>> -                      user_sseu.engine_class,
>> -                      user_sseu.engine_instance);
>> +                      user_sseu.engine.engine_class,
>> +                      user_sseu.engine.engine_instance);
>>       if (!engine)
>>           return -EINVAL;
>>   diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
>> index 52051d24d89d..bbc453b1e50f 100644
>> --- a/include/uapi/drm/i915_drm.h
>> +++ b/include/uapi/drm/i915_drm.h
>> @@ -126,6 +126,19 @@ enum drm_i915_gem_engine_class {
>>       I915_ENGINE_CLASS_INVALID    = -1
>>   };
>>   +
>> +/*
>> + * There may be more than one engine fulfilling any role within the 
>> system.
>> + * Each engine of a class is given a unique instance number and 
>> therefore
>> + * any engine can be specified by its class:instance tuplet. APIs 
>> that allow
>> + * access to any engine in the system will use struct 
>> i915_engine_class_instance
>> + * for this identification.
>> + */
>> +struct i915_engine_class_instance {
>> +    __u16 engine_class; /* see enum drm_i915_gem_engine_class */
>> +    __u16 engine_instance;
>> +};
>> +
>>   /**
>>    * DOC: perf_events exposed by i915 through 
>> /sys/bus/event_sources/drivers/i915
>>    *
>> @@ -1525,8 +1538,7 @@ struct drm_i915_gem_context_param_sseu {
>>       /*
>>        * Engine class & instance to be configured or queried.
>>        */
>> -    __u16 engine_class;
>> -    __u16 engine_instance;
>> +    struct i915_engine_class_instance engine;
>>         /*
>>        * Unused for now. Must be cleared to zero.
>>
>
> This will definitely be tidier in the near future (despite a bit of 
> ugliness in engine.engine_*). I have also checked that this indeed is 
> part of 5.1 which hasn't been shipped yet.
>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>
> If we can get an ack from Joonas and Tony, to whom it probably falls 
> to do the media-driver change I think we are good to do.
>
> Regards,
>
> Tvrtko

Acked-by: Tony Ye <tony.ye at intel.com>

Regards, --Tony