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];
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
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