drm/fb_cma_helper: Implement fb_mmap callback
authorRobin Murphy <robin.murphy@arm.com>
Tue, 7 Jun 2016 12:18:09 +0000 (13:18 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 7 Jun 2016 19:43:12 +0000 (21:43 +0200)
commitce0c5757681052eb8965209129f28362c3a4d8a7
tree45b69cd544c5ec152fe78389b3910442952f1f66
parentcb76e3560a271ce570dff60869ddba1a08486c92
drm/fb_cma_helper: Implement fb_mmap callback

In the absence of an fb_mmap callback, the fbdev code falls back to a
naive implementation which relies upon the DMA address being the same
as the physical address, and the buffer being physically contiguous
from there. Whilst this often holds for standard CMA allocations via
the platform's regular DMA ops, if the allocation is provided by an
IOMMU then such assumptions can fall apart spectacularly.

To resolve this, reroute the fb_mmap call to the appropriate DMA API
implementation, as per the other cma_helper calls.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/8fd95ac1440e0f01daad6d4380be3a4c8fa61055.1465301219.git.robin.murphy@arm.com
drivers/gpu/drm/drm_fb_cma_helper.c