1. 06 Jul, 2012 1 commit
  2. 08 Dec, 2011 2 commits
    • Rob Clark's avatar
      drm/omap: add GEM support for tiled/dmm buffers · f7f9f453
      Rob Clark authored
      
      
      TILER/DMM provides two features for omapdrm GEM objects:
      1) providing a physically contiguous view to discontiguous memory
         for hw initiators that cannot otherwise support discontiguous
         buffers (DSS scanout, IVAHD video decode/encode, etc)
      2) providing untiling for 2d tiled buffers, which are used in some
         cases to provide rotation and reduce memory bandwidth for hw
         initiators that tend to access data in 2d block patterns.
      
      For 2d tiled buffers, there are some additional complications when
      it comes to userspace mmap'ings.  For non-tiled buffers, the original
      (potentially physically discontiguous) pages are used to back the
      mmap.  For tiled buffers, we need to mmap via the tiler/dmm region to
      provide an unswizzled view of the buffer.  But (a) the buffer is not
      necessarily pinned in TILER all the time (it can be unmapped when
      there is no DMA access to the buffer), and (b) when they are they
      are pinned, they not necessarily page aligned from the perspective of
      the CPU.  And non-page aligned userspace buffer mapping is evil.
      
      To solve this, we reserve one or more small regions in each of the 2d
      containers when the driver is loaded to use as a "user-GART" where we
      can create a second page-aligned mapping of parts of the buffer being
      accessed from userspace.  Page faulting is used to evict and remap
      different regions of whichever buffers are being accessed from user-
      space.
      Signed-off-by: default avatarRob Clark <rob@ti.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      f7f9f453
    • Andy Gross's avatar
      drm/omap: DMM/TILER support for OMAP4+ platform · 71e8831f
      Andy Gross authored
      
      
      Dynamic Memory Manager (DMM) is a hardware block in the OMAP4+
      processor that contains at least one TILER instance.  TILER, or
      Tiling and Isometric Lightweight Engine for Rotation, provides
      IOMMU capabilities through the use of a physical address translation
      table.  The TILER also provides zero cost rotation and mirroring.
      
      The TILER provides both 1D and 2D access by providing different views
      or address ranges that can be used to access the physical memory that
      has been mapped in through the PAT.  Access to the 1D view results in
      linear access to the underlying memory.  Access to the 2D views result
      in tiled access to the underlying memory resulted in increased
      efficiency.
      
      The TILER address space is managed by a tiler container manager (TCM)
      and allocates the address space through the use of the Simple Tiler
      Allocation algorithm (SiTA).  The purpose of the algorithm is to keep
      fragmentation of the address space as low as possible.
      Signed-off-by: default avatarAndy Gross <andy.gross@ti.com>
      Signed-off-by: default avatarRob Clark <rob@ti.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      71e8831f
  3. 26 Nov, 2011 1 commit
    • Rob Clark's avatar
      staging: add omapdrm DRM/KMS driver for TI OMAP platforms · cd5351f4
      Rob Clark authored
      A DRM display driver for TI OMAP platform.  Similar to omapfb (fbdev)
      and omap_vout (v4l2 display) drivers in the past, this driver uses the
      DSS2 driver to access the display hardware, including support for
      HDMI, DVI, and various types of LCD panels.  And it implements GEM
      support for buffer allocation (for KMS as well as offscreen buffers
      used by the xf86-video-omap userspace xorg driver).
      
      The driver maps CRTCs to overlays, encoders to overlay-managers, and
      connectors to dssdev's.  Note that this arrangement might change slightly
      when support for drm_plane overlays is added.
      
      For GEM support, non-scanout buffers are using the shmem backed pages
      provided by GEM core (In drm_gem_object_init()).  In the case of scanout
      buffers, which need to be physically contiguous, those are allocated
      with CMA and use drm_gem_private_object_init().
      
      See userspace xorg driver:
      git://github.com/robclark/xf86-video-omap.git
      
      Refer to this link for CMA (Continuous Memory Allocator):
      http://lkml.org/lkml/2011/8/19/302
      
      Links to previous versions of the patch:
      v1: http://lwn.net/Articles/458137/
      v2: http://patches.linaro.org/4156/
      v3: http://patches.linaro.org/4688/
      v4: http://patches.linaro.org/4791/
      
      
      
      History:
      
      v5: move headers from include/drm at Greg KH's request, minor rebasing
          on 3.2-rc1, pull in private copies of drm_gem_{get,put}_pages()
          because "drm/gem: add functions to get/put pages" patch is not
          merged yet
      v4: bit of rework of encoder/connector _dpms() code, modeset_init()
          rework to not use nested functions, update TODO.txt
      v3: minor cleanups, improved error handling for dev_load(), some minor
          API changes that will be needed later for tiled buffer support
      v2: replace omap_vram with CMA for scanout buffer allocation, remove
          unneeded functions, use dma_addr_t for physical addresses, error
          handling cleanup, refactor attach/detach pages into common drm
          functions, split non-userspace-facing API into omap_priv.h, remove
          plugin API
      
      v1: original
      Signed-off-by: default avatarRob Clark <rob@ti.com>
      Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      cd5351f4