After rollover of the IOVA space, we want to get a low IOVA address,
otherwise the the games we play by remembering the last IOVA are
pointless. When we search for a free hole with DRM_MM_SEARCH_DEFAULT,
drm_mm will pop the next entry from the free holes stack, which will
likely be a high IOVA. By using DRM_MM_SEARCH_BELOW we can trick
drm_mm into reversing the search and provide us with a low IOVA.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Wladimir van der Laan <laanwj@gmail.com>

To make sure we don't place anything there which might confuse
the FE prefetcher. This gets rid of another case of FE MMU faults
when the address space gets crowded before triggering the reaper.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

At least on the GC3000 the FE MMU is not properly flushing stale TLB
entries. Make sure to map the cmdbufs with a big enough spacing in
the IOVAs to not hit old/prefetched TLB entries when jumping to a
newly mapped cmdbuf.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

All other parts are now in place, so implement the actual translation
step and hook it up, so the driver claims support for cores with
the new MMU.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

With MMUv2 all buffers need to be mapped through the MMU once it
is enabled. Align the buffer size to 4K, as the MMU is only able to
map page aligned buffers.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

With MMUv2 the command buffers need to be mapped through the MMU.
Split out the iova search and MMU reaping logic so it can be reused
for the cmdbuf mapping, where no GEM object is involved.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

The GPU virtual address for the command buffers differs depending on
the IOMMU version. Move the calculation of the iova into etnaviv
mmu, to enable proper dispatch.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

The GPU code doesn't need to deal with the IOMMU directly, instead
it can all be hidden behind the etnaviv mmu interface. Move the
last remaining part into etnaviv mmu.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

So we can call the v2 restore code once it is there.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

As the comment above the code states, the linear window is only
available on MMUv1. Don't try to use it on MMUv2.
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>