Quoting Tvrtko Ursulin (2018-04-18 12:33:42)
> From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
>
> Currently our driver assumes BSD2 means hardware engine instance number
> two. This does not work for Icelake parts with two VCS engines, but which
> are hardware instances 0 and 2, and not 0 and 1 as with previous parts.
>
> This makes the second engine not discoverable via HAS_BSD2 get param, nor
> it can be targetted by execbuf.
>
> While we are working on the next generation execbuf put in a hack which
> allows discovery and access to this second VCS engine using legacy ABI.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> Cc: Jon Bloomfield <jon.bloomfield@xxxxxxxxx>
> Cc: Tony Ye <tony.ye@xxxxxxxxx>
> ---
> Compile tested only.
>
> Also, one could argue if this is just a temporary hack or could actually
> make sense to have this permanently in. It feels like the ABI semantics of
> BSD2 are blurry, or at least could be re-blurred for Gen11.
> ---
> drivers/gpu/drm/i915/i915_drv.c | 8 +++++++-
> drivers/gpu/drm/i915/i915_gem_execbuffer.c | 10 +++++++++-
> 2 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index b7dbeba72dec..a185366d9beb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -331,7 +331,13 @@ static int i915_getparam_ioctl(struct drm_device *dev, void *data,
> value = !!dev_priv->engine[VECS];
> break;
> case I915_PARAM_HAS_BSD2:
> - value = !!dev_priv->engine[VCS2];
> + /*
> + * FIXME: Temporary hack for Icelake.
> + *
> + * Make semantics of HAS_BSD2 "has second", or "has two" VDBOXes
> + * instead of "has VDBOX 2nd hardware instance".
> + */
> + value = dev_priv->engine[VCS2] || dev_priv->engine[VCS3];
There can be no temporary hacks for the uAPI... You either sign yourself
up to keep it working indefinitely or don't :)
Regards, Joonas
> break;
> case I915_PARAM_HAS_LLC:
> value = HAS_LLC(dev_priv);
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index c74f5df3fb5a..80b32460567d 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -2052,7 +2052,9 @@ eb_select_engine(struct drm_i915_private *dev_priv,
> return NULL;
> }
>
> - if (user_ring_id == I915_EXEC_BSD && HAS_BSD2(dev_priv)) {
> + if (user_ring_id == I915_EXEC_BSD &&
> + (INTEL_INFO(dev_priv)->ring_mask &
> + (ENGINE_MASK(_VCS(1)) | ENGINE_MASK(_VCS(2))))) {
> unsigned int bsd_idx = args->flags & I915_EXEC_BSD_MASK;
>
> if (bsd_idx == I915_EXEC_BSD_DEFAULT) {
> @@ -2068,6 +2070,12 @@ eb_select_engine(struct drm_i915_private *dev_priv,
> }
>
> engine = dev_priv->engine[_VCS(bsd_idx)];
> +
> + /*
> + * FIXME Temporarily map VCS2 to VCS1 on Icelake.
> + */
> + if (!engine && bsd_idx)
> + engine = dev_priv->engine[_VCS(2)];
> } else {
> engine = dev_priv->engine[user_ring_map[user_ring_id]];
> }
> --
> 2.14.1
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
