[Intel-xe] [RFC PATCH v3 2/2] drm/xe/uapi: Add query engines uAPI

[Matthew Brost]

On Thu, Mar 23, 2023 at 09:43:24AM +0000, Matthew Auld wrote:
> On Thu, 23 Mar 2023 at 02:58, Matthew Brost <matthew.brost at intel.com> wrote:
> >
> > Not all hardware engines are created equally, certain instance have
> > unique capabilities or properties. Introduce a uAPI to query for both
> > capabilities and properties. The capabilities are represented by a bit
> > mask which is unique to each class. The properties are represented by a
> > name and value return in an array to the user.
> >
> > v3: s/xe_engine/xe_hw_engine
> >
> > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> > ---
> >  include/uapi/drm/xe_drm.h | 41 +++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 41 insertions(+)
> >
> > diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> > index 89596d353d3e..2f936fe2e452 100644
> > --- a/include/uapi/drm/xe_drm.h
> > +++ b/include/uapi/drm/xe_drm.h
> > @@ -119,6 +119,7 @@ struct xe_user_extension {
> >  #define DRM_XE_WAIT_USER_FENCE         0x0b
> >  #define DRM_XE_VM_MADVISE              0x0c
> >  #define DRM_XE_ENGINE_GET_PROPERTY     0x0d
> > +#define DRM_XE_HW_ENGINE_QUERY         0x0f
> >
> >  /* Must be kept compact -- no holes */
> >  #define DRM_IOCTL_XE_DEVICE_QUERY              DRM_IOWR(DRM_COMMAND_BASE + DRM_XE_DEVICE_QUERY, struct drm_xe_device_query)
> > @@ -135,6 +136,7 @@ struct xe_user_extension {
> >  #define DRM_IOCTL_XE_ENGINE_SET_PROPERTY       DRM_IOW( DRM_COMMAND_BASE + DRM_XE_ENGINE_SET_PROPERTY, struct drm_xe_engine_set_property)
> >  #define DRM_IOCTL_XE_WAIT_USER_FENCE           DRM_IOWR(DRM_COMMAND_BASE + DRM_XE_WAIT_USER_FENCE, struct drm_xe_wait_user_fence)
> >  #define DRM_IOCTL_XE_VM_MADVISE                        DRM_IOW( DRM_COMMAND_BASE + DRM_XE_VM_MADVISE, struct drm_xe_vm_madvise)
> > +#define DRM_IOCTL_XE_ENGINE_QUERY              DRM_IOWR(DRM_COMMAND_BASE + DRM_XE_HW_ENGINE_QUERY, struct drm_xe_hw_engine_query)
> >
> >  struct drm_xe_hw_engine_class_instance {
> >         __u16 engine_class;
> > @@ -253,6 +255,45 @@ struct drm_xe_device_query {
> >         __u64 reserved[2];
> >  };
> >
> > +struct drm_xe_hw_engine_query_property {
> > +       /** @name: name of the property */
> > +       __u64 name;
> > +
> > +       /** @value: value property */
> > +       __u64 value;
> > +
> > +       /** @reserved: reserved */
> > +       __u64 reserved[2];
> > +};
> > +
> > +struct drm_xe_hw_engine_query {
> > +       /** @extensions: pointer to the first extension struct, if any */
> > +       __u64 extensions;
> > +
> > +       /** @eci: engine class instance to query */
> > +       struct drm_xe_hw_engine_class_instance eci;
> > +
> > +       /** @capabilities: bit mask of capabilities, specific to each class */
> > +       __u64 capabilities;
> > +
> > +       /**
> > +        * @size: Size of the queried properties, if user passes in zero the KMD
> > +        * returns the size of the properties array, if user passes in the size
> > +        * of the properties array the KMD copies the properties to the user
> > +        * pointer.
> > +        */
> > +       __u32 size;
> 
> Just a drive-by-comment, AFAICT we need some kind of __u32 pad here?
> 

Probably should have that, world breaking change though so needs to be coordinated.

Matt

> > +
> > +       /**
> > +        * @properties: user pointer to which an array of  struct
> > +        * drm_xe_hw_engine_query_property are copied to if size is non-zero
> > +        */
> > +       __u64 properties;
> > +
> > +       /** @reserved: reserved */
> > +       __u64 reserved[2];
> > +};
> > +
> >  struct drm_xe_gem_create {
> >         /** @extensions: Pointer to the first extension struct, if any */
> >         __u64 extensions;
> > --
> > 2.34.1
> >