From: Oscar Mateo Date: Thu, 24 Jul 2014 16:04:13 +0000 (+0100) Subject: drm/i915/bdw: Introduce one context backing object per engine X-Git-Tag: fixes-against-v3.18-rc2~73^2~73^2~63 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c9e003af2d44d9f6eafe855448c41c9ac08ae895;p=pandora-kernel.git drm/i915/bdw: Introduce one context backing object per engine A context backing object only makes sense for a given engine (because it holds state data specific to that engine). In legacy ringbuffer sumission mode, the only MI_SET_CONTEXT we really perform is for the render engine, so one backing object is all we nee. With Execlists, however, we need backing objects for every engine, as contexts become the only way to submit workloads to the GPU. To tackle this problem, we multiplex the context struct to contain objects. Originally, I colored this code by instantiating one new context for every engine I wanted to use, but this change suggested by Brad Volkin makes it more elegant. v2: Leave the old backing object pointer behind. Daniel Vetter suggested using a union, but it makes more sense to keep rcs_state as a NULL pointer behind, to make sure no one uses it incorrectly when Execlists are enabled, similar to what he suggested for ring->buffer (Rusty's API level 5). v3: Use the name "state" instead of the too-generic "obj", so that it mirrors the name choice for the legacy rcs_state. Signed-off-by: Oscar Mateo Reviewed-by: Damien Lespiau Signed-off-by: Daniel Vetter --- Reading git-diff-tree failed