[PATCH v4] DRM: add drm gem CMA helper

[Dave Airlie]

On Thu, Aug 9, 2012 at 2:31 AM, Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
> Hi Lars,
>
> On Wednesday 08 August 2012 18:25:30 Lars-Peter Clausen wrote:
>> On 08/08/2012 04:44 PM, Laurent Pinchart wrote:
>> > On Wednesday 27 June 2012 15:30:18 Sascha Hauer wrote:
>> >> Many embedded drm devices do not have a IOMMU and no dedicated
>> >> memory for graphics. These devices use CMA (Contiguous Memory
>> >> Allocator) backed graphics memory. This patch provides helper
>> >> functions to be able to share the code. The code technically does
>> >> not depend on CMA as the backend allocator, the name has been chosen
>> >> because cma makes for a nice, short but still descriptive function
>> >> prefix.
>> >>
>> >> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
>> >> ---
>> >>
>> >> changes since v3:
>> >> - *really* use DIV_ROUND_UP(args->width * args->bpp, 8) to calculate the
>> >> pitch changes since v2:
>> >> - make drm_gem_cma_create_with_handle static
>> >> - use DIV_ROUND_UP(args->width * args->bpp, 8) to calculate the pitch
>> >> - make drm_gem_cma_vm_ops const
>> >> - add missing #include <linux/export.h>
>> >> changes since v1:
>> >> - map whole buffer at mmap time, not page by page at fault time
>> >> - several cleanups as suggested by Lars-Peter Clausen and Laurent
>> >> Pinchart
>> >>
>> >>  drivers/gpu/drm/Kconfig              |    6 +
>> >>  drivers/gpu/drm/Makefile             |    1 +
>> >>  drivers/gpu/drm/drm_gem_cma_helper.c |  251
>> >>  +++++++++++++++++++++++++++++++
>> >>  include/drm/drm_gem_cma_helper.h     |   44 ++++++
>> >>  4 files changed, 302 insertions(+)
>> >>  create mode 100644 drivers/gpu/drm/drm_gem_cma_helper.c
>> >>  create mode 100644 include/drm/drm_gem_cma_helper.h
>> >>
>> >> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>> >> index dc5df12..8f362ec 100644
>> >> --- a/drivers/gpu/drm/Kconfig
>> >> +++ b/drivers/gpu/drm/Kconfig
>> >> @@ -53,6 +53,12 @@ config DRM_TTM
>> >>
>> >>      GPU memory types. Will be enabled automatically if a device driver
>> >>      uses it.
>> >>
>> >> +config DRM_GEM_CMA_HELPER
>> >> +  tristate
>> >> +  depends on DRM
>> >> +  help
>> >> +    Choose this if you need the GEM CMA helper functions
>> >> +
>> >>
>> >>  config DRM_TDFX
>> >>
>> >>    tristate "3dfx Banshee/Voodoo3+"
>> >>    depends on DRM && PCI
>> >>
>> >> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
>> >> index 0487ff6..8759cda 100644
>> >> --- a/drivers/gpu/drm/Makefile
>> >> +++ b/drivers/gpu/drm/Makefile
>> >> @@ -15,6 +15,7 @@ drm-y       :=   drm_auth.o drm_buffer.o drm_bufs.o
>> >> drm_cache.o \ drm_trace_points.o drm_global.o drm_prime.o
>> >>
>> >>  drm-$(CONFIG_COMPAT) += drm_ioc32.o
>> >>
>> >> +drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
>> >
>> > This results in a built failure for me with
>> >
>> > CONFIG_DRM=y
>> > CONFIG_DRM_KMS_HELPER=m
>> > # CONFIG_DRM_LOAD_EDID_FIRMWARE is not set
>> > CONFIG_DRM_GEM_CMA_HELPER=m
>> > CONFIG_DRM_KMS_CMA_HELPER=m
>> >
>> > drm_gem_cma_helper.o isn't compiled at all. Can you reproduce the problem
>> > ?
>>
>> The Kconfig entry needs to be bool instead of tristate.
>
> That's my preferred solution as well. I'll modify the patch in my tree, unless
> Sascha wants to submit a v5.

Oh I keep missing this, I've no objections to putting it into -next,
if someone sends one clean patch to the list with sign offs that I can
grab easily.

Dave.