Several multi-line comments added at the vsp1 patch series
violate the Kernel CodingStyle. Fix them.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

When display lists are linked in a chain, they will be processed
automatically by the hardware, with each list linking to the next. Only
on the last display list will the frame end interrupt be fired to mark
the completion event.

Upon frame-end, the chain will be iterated to release each display list
back to the free list.

The chained lists use case (image partitioning) can require up to 64
lists per frame in the worst case scenario, bump up the number of
preallocated lists.
Signed-off-by: NKieran Bingham <kieran+renesas@bingham.xyz>
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Freeing a fragment requires freeing DMA coherent memory, which can be
performed with interrupts disabled as per the DMA mapping API contract.
The fragments can't thus be freed synchronously when a display list is
recycled. Instead, move the fragments to a garbage list and use a work
queue to run the garbage collection.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Display lists support up to 8 bodies but we currently use a single one.
To support preparing display lists for large look-up tables, add support
for multi-body display lists.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The vsp1_dl_list_put() function expects to be called with the display
list manager lock held. This assumption is correct for calls from within
the vsp1_dl.c file, but not for the external calls. Fix it by taking the
lock inside the function and providing an unlocked version for the
internal callers.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The field takes positive values only, make it unsigned.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Don't restrict display list usage to the DRM pipeline, use them
unconditionally. This prepares the driver to support the request API.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Display lists can operate in header or headerless mode. The headerless
mode is only available on WPF0, to be used with the display engine. All
other WPF instances can only use display lists in header mode.

Implement support for header mode to prepare for display list usage on
WPFs other than 0.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Each WPF can process display lists independently, move the manager to
the WPF to reflect that and prepare for display list support for non-DRM
pipelines.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This clarifies the API and prepares display list support for being used
to implement the request API.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Make sure display list usage is correctly disabled by always setting up
the corresponding registers, including when the display list feature
isn't used.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This allows getting rid of the vsp1_device::use_dl field.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

I noticed this while merging the drm tree and checking for stragglers:
the vsp1 driver still used dma_[alloc|free]_writecombine() that got
renamed in commit f6e45661 ("dma, mm/pat: Rename
dma_*_writecombine() to dma_*_wc()")

I should have noticed back in the media merge (commit bace3db5), but
better late than never.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Display lists contain lists of registers and associated values to be
applied atomically by the hardware. They lower the pressure on interrupt
processing delays when reprogramming the device as settings can be
prepared well in advance and queued to the hardware without waiting for
the end of the current frame.

Display list support is currently limited to the DRM pipeline.
Signed-off-by: NKoji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>