Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux

Pull drm updates from Dave Airlie:
 "This is the main drm pull request for 4.6 kernel.

  Overall the coolest thing here for me is the nouveau maxwell signed
  firmware support from NVidia, it's taken a long while to extract this
  from them.

  I also wish the ARM vendors just designed one set of display IP, ARM
  display block proliferation is definitely increasing.

  Core:
     - drm_event cleanups
     - Internal API cleanup making mode_fixup optional.
     - Apple GMUX vga switcheroo support.
     - DP AUX testing interface

  Panel:
     - Refactoring of DSI core for use over more transports.

  New driver:
     - ARM hdlcd driver

  i915:
     - FBC/PSR (framebuffer compression, panel self refresh) enabled by default.
     - Ongoing atomic display support work
     - Ongoing runtime PM work
     - Pixel clock limit checks
     - VBT DSI description support
     - GEM fixes
     - GuC firmware scheduler enhancements

  amdkfd:
     - Deferred probing fixes to avoid make file or link ordering.

  amdgpu/radeon:
     - ACP support for i2s audio support.
     - Command Submission/GPU scheduler/GPUVM optimisations
     - Initial GPU reset support for amdgpu

  vmwgfx:
     - Support for DX10 gen mipmaps
     - Pageflipping and other fixes.

  exynos:
     - Exynos5420 SoC support for FIMD
     - Exynos5422 SoC support for MIPI-DSI

  nouveau:
     - GM20x secure boot support - adds acceleration for Maxwell GPUs.
     - GM200 support
     - GM20B clock driver support
     - Power sensors work

  etnaviv:
     - Correctness fixes for GPU cache flushing
     - Better support for i.MX6 systems.

  imx-drm:
     - VBlank IRQ support
     - Fence support
     - OF endpoint support

  msm:
     - HDMI support for 8996 (snapdragon 820)
     - Adreno 430 support
     - Timestamp queries support

  virtio-gpu:
     - Fixes for Android support.

  rockchip:
     - Add support for Innosilicion HDMI

  rcar-du:
     - Support for 4 crtcs
     - R8A7795 support
     - RCar Gen 3 support

  omapdrm:
     - HDMI interlace output support
     - dma-buf import support
     - Refactoring to remove a lot of legacy code.

  tilcdc:
     - Rewrite of pageflipping code
     - dma-buf support
     - pinctrl support

  vc4:
     - HDMI modesetting bug fixes
     - Significant 3D performance improvement.

  fsl-dcu (FreeScale):
     - Lots of fixes

  tegra:
     - Two small fixes

  sti:
     - Atomic support for planes
     - Improved HDMI support"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (1063 commits)
  drm/amdgpu: release_pages requires linux/pagemap.h
  drm/sti: restore mode_fixup callback
  drm/amdgpu/gfx7: add MTYPE definition
  drm/amdgpu: removing BO_VAs shouldn't be interruptible
  drm/amd/powerplay: show uvd/vce power gate enablement for tonga.
  drm/amd/powerplay: show uvd/vce power gate info for fiji
  drm/amdgpu: use sched fence if possible
  drm/amdgpu: move ib.fence to job.fence
  drm/amdgpu: give a fence param to ib_free
  drm/amdgpu: include the right version of gmc header files for iceland
  drm/radeon: fix indentation.
  drm/amd/powerplay: add uvd/vce dpm enabling flag to fix the performance issue for CZ
  drm/amdgpu: switch back to 32bit hw fences v2
  drm/amdgpu: remove amdgpu_fence_is_signaled
  drm/amdgpu: drop the extra fence range check v2
  drm/amdgpu: signal fences directly in amdgpu_fence_process
  drm/amdgpu: cleanup amdgpu_fence_wait_empty v2
  drm/amdgpu: keep all fences in an RCU protected array v2
  drm/amdgpu: add number of hardware submissions to amdgpu_fence_driver_init_ring
  drm/amdgpu: RCU protected amd_sched_fence_release
  ...

1 files changed, 28 insertions, 12 deletions

diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt
index 480c8de3c2c4..32ac32e773e1 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -257,17 +257,15 @@ Access to a dma_buf from the kernel context involves three steps:
 
    Interface:
       int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
-				   size_t start, size_t len,
 				   enum dma_data_direction direction)
 
    This allows the exporter to ensure that the memory is actually available for
    cpu access - the exporter might need to allocate or swap-in and pin the
    backing storage. The exporter also needs to ensure that cpu access is
-   coherent for the given range and access direction. The range and access
-   direction can be used by the exporter to optimize the cache flushing, i.e.
-   access outside of the range or with a different direction (read instead of
-   write) might return stale or even bogus data (e.g. when the exporter needs to
-   copy the data to temporary storage).
+   coherent for the access direction. The direction can be used by the exporter
+   to optimize the cache flushing, i.e. access with a different direction (read
+   instead of write) might return stale or even bogus data (e.g. when the
+   exporter needs to copy the data to temporary storage).
 
    This step might fail, e.g. in oom conditions.
 
@@ -322,14 +320,13 @@ Access to a dma_buf from the kernel context involves three steps:
 
 3. Finish access
 
-   When the importer is done accessing the range specified in begin_cpu_access,
-   it needs to announce this to the exporter (to facilitate cache flushing and
-   unpinning of any pinned resources). The result of any dma_buf kmap calls
-   after end_cpu_access is undefined.
+   When the importer is done accessing the CPU, it needs to announce this to
+   the exporter (to facilitate cache flushing and unpinning of any pinned
+   resources). The result of any dma_buf kmap calls after end_cpu_access is
+   undefined.
 
    Interface:
       void dma_buf_end_cpu_access(struct dma_buf *dma_buf,
-				  size_t start, size_t len,
 				  enum dma_data_direction dir);
 
 
@@ -353,7 +350,26 @@ Being able to mmap an export dma-buf buffer object has 2 main use-cases:
    handles, too). So it's beneficial to support this in a similar fashion on
    dma-buf to have a good transition path for existing Android userspace.
 
-   No special interfaces, userspace simply calls mmap on the dma-buf fd.
+   No special interfaces, userspace simply calls mmap on the dma-buf fd, making
+   sure that the cache synchronization ioctl (DMA_BUF_IOCTL_SYNC) is *always*
+   used when the access happens. This is discussed next paragraphs.
+
+   Some systems might need some sort of cache coherency management e.g. when
+   CPU and GPU domains are being accessed through dma-buf at the same time. To
+   circumvent this problem there are begin/end coherency markers, that forward
+   directly to existing dma-buf device drivers vfunc hooks. Userspace can make
+   use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The sequence
+   would be used like following:
+     - mmap dma-buf fd
+     - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write
+       to mmap area 3. SYNC_END ioctl. This can be repeated as often as you
+       want (with the new data being consumed by the GPU or say scanout device)
+     - munmap once you don't need the buffer any more
+
+    Therefore, for correctness and optimal performance, systems with the memory
+    cache shared by the GPU and CPU i.e. the "coherent" and also the
+    "incoherent" are always required to use SYNC_START and SYNC_END before and
+    after, respectively, when accessing the mapped address.
 
 2. Supporting existing mmap interfaces in importers