There are 3 big benefits to suballocating a single big DMA buffer
for command submission:
1. Avoid hammering CMA. The old way of allocating and freeing a DMA
buffer for each submission was hitting some of the real slow
pathes in CMA, as this allocator was not designed for a concurrent
small buffers load.
2. Less TLB flushes on IOMMUv2. If a new command buffer is mapped into
the GPU address space the MMU TLBs need to be flushed. By having
one big buffer statically mapped to the GPU, a lot of those flushes
can be avoided.
3. No funky workarounds for GC3000. The FE TLB flush on GC3000 isn't
reliable. To work around that we tried to lay out the cmdbufs in
the GPU address space in a way to avoid this issue. This hasn't
always worked if the address space is crowded. A single statically
mapped buffer avoids the erratum completely.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
This will get more complex with the following changes, so move it
into its own place.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
This function had copies in 3 different files. Unify them in kernel.h.
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Acked-by: Daniel Vetter <daniel.vetter@intel.com> [drm/i915/]
Acked-by: Rob Clark <robdclark@gmail.com> [drm/msm/]
Acked-by: Lucas Stach <l.stach@pengutronix.de> [drm/etinav/]
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As we now store the etnaviv_vram_mapping, we no longer need to store
the iova itself: we can get this directly from the mapping structure.
Arrange for submit_bo() to return a pointer to etnaviv_gem_submit_bo,
and directly access mapping->iova when applying relocations.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Currently, we scan the list of mappings each time we want to operate on
the vram_mapping struct. Rather than repeatedly scanning these, look
them up once in the submission path, and then use _reference and
_unreference methods as necessary to manage this object.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
This adds the etnaviv DRM driver and hooks it up in Makefiles
and Kconfig.
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
