commit 41315b793e upstream.
Rather than (incompletely [0]) re-implementing drm_gem_mmap() and
drm_gem_mmap_obj() helpers, call them directly from the rockchip mmap
routines.
Once the core functions return successfully, the rockchip mmap routines
can still use dma_mmap_attrs() to simply mmap the entire buffer.
[0] Previously, we were performing the mmap() without first taking a
reference on the underlying gem buffer. This could leak ptes if the gem
object is destroyed while userspace is still holding the mapping.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In general, the data in drm/rockchip GEM objects is never accessed by
the kernel. The objects are either accessed by a GPU, by display
controller DMA, or by mmap'ing them to user space. Thus, these
buffers need not be mapped into kernel address space.
The only exception is the fbdev framebuffer(s), which may be written
in-kernel by fbcon.
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
dma_alloc_attrs() returns NULL if it cannot allocate a dma buffer (or
mapping), not a negative error code.
Rerported-by: Pawel Osciak <posciak@chromium.org>
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
