linux/drivers/gpu/drm
Daniel Vetter c2fcd274bc drm: Add atomic/plane helpers
This is the first cut of atomic helper code. As-is it's only useful to
implement a pure atomic interface for plane updates.

Later patches will integrate this with the crtc helpers so that full
atomic updates are possible. We also need a pile of helpers to aid
drivers in transitioning from the legacy world to the shiny new atomic
age. Finally we need helpers to implement legacy ioctls on top of the
atomic interface.

The design of the overall helpers<->driver interaction is fairly
simple, but has an unfortunate large interface:

- We have ->atomic_check callbacks for crtcs and planes. The idea is
  that connectors don't need any checking, and if they do they can
  adjust the relevant crtc driver-private state. So no connector hooks
  should be needed. Also the crtc helpers integration will do the
  ->best_encoder checks, so no need for that.

- Framebuffer pinning needs to be done before we can commit to the hw
  state. This is especially important for async updates where we must
  pin all buffers before returning to userspace, so that really only
  hw failures can happen in the asynchronous worker.

  Hence we add ->prepare_fb and ->cleanup_fb hooks for this resources
  management.

- The actual atomic plane commit can't fail (except hw woes), so has
  void return type. It has three stages:
  1. Prepare all affected crtcs with crtc->atomic_begin. Drivers can
     use this to unset the GO bit or similar latches to prevent plane
     updates.
  2. Update plane state by looping over all changed planes and calling
     plane->atomic_update. Presuming the hardware is sane and has GO
     bits drivers can simply bash the state into the hardware in this
     function. Other drivers might use this to precompute hw state for
     the final step.
  3. Finally latch the update for the next vblank with
     crtc->atomic_flush. Note that this function doesn't need to wait
     for the vblank to happen even for the synchronous case.

v2: Clear drm_<obj>_state->state to NULL when swapping in state.

v3: Add TODO that we don't short-circuit plane updates for now. Likely
no one will care.

v4: Squash in a bit of polish that somehow landed in the wrong (later)
patche.

v5: Integrate atomic functions into the drm docbook and fixup the
kerneldoc.

v6: Fixup fixup patch squashing fumble.

v7: Don't touch the legacy plane state plane->fb and plane->crtc. This
is only used by the legacy ioctl code in the drm core, and that code
already takes care of updating the pointers in all relevant cases.
This is in stark contrast to connector->encoder->crtc links on the
modeset side, which we still need to set since the core doesn't touch
them.

Also some more kerneldoc polish.

v8: Drop outdated comment.

v9: Handle the state->state pointer correctly: Only clearing the
->state pointer when assigning the state to the kms object isn't good
enough. We also need to re-link the swapped out state into the
drm_atomic_state structure.

v10: Shuffle the misplaced docbook template hunk around that Sean spotted.

Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-11-05 18:07:01 +01:00
..
armada drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
ast drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
bochs drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
bridge
cirrus drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
exynos drm: Extract <drm/drm_gem.h> 2014-09-24 11:43:41 +10:00
gma500 drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
i2c drm/tda998x: update for new drm connector APIs. 2014-08-05 10:34:33 +10:00
i810 drm: move drm_mmap to <drm/drm_legacy.h> 2014-09-24 11:43:07 +10:00
i915 Merge tag 'drm-intel-next-2014-10-03-no-ppgtt' of git://anongit.freedesktop.org/drm-intel into drm-next 2014-10-28 12:37:58 +10:00
mga drm: move drm_mmap to <drm/drm_legacy.h> 2014-09-24 11:43:07 +10:00
mgag200 drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
msm drm: Pass dma-buf as argument to gem_prime_import_sg_table 2014-09-30 14:04:00 +02:00
nouveau drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
omapdrm drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
panel drm/panel/simple: add optronics B101XTN01.0 (v3) 2014-09-10 11:19:07 -04:00
qxl drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
r128 drm: move drm_mmap to <drm/drm_legacy.h> 2014-09-24 11:43:07 +10:00
radeon drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
rcar-du drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
savage drm: move drm_mmap to <drm/drm_legacy.h> 2014-09-24 11:43:07 +10:00
shmobile drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
sis drm: move drm_mmap to <drm/drm_legacy.h> 2014-09-24 11:43:07 +10:00
sti drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
tdfx drm: move drm_mmap to <drm/drm_legacy.h> 2014-09-24 11:43:07 +10:00
tegra drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
tilcdc drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
ttm drm/ttm: Don't evict BOs outside of the requested placement range 2014-10-16 18:34:08 -04:00
udl drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
via drm: move drm_mmap to <drm/drm_legacy.h> 2014-09-24 11:43:07 +10:00
vmwgfx drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h 2014-11-05 00:14:55 +01:00
ati_pcigart.c drm: split ati_pcigart.h out of drmP.h 2014-09-12 14:11:14 +10:00
drm_agpsupport.c drm: move AGP definitions harder 2014-09-10 17:40:11 +10:00
drm_atomic_helper.c drm: Add atomic/plane helpers 2014-11-05 18:07:01 +01:00
drm_atomic.c drm: Global atomic state handling 2014-11-05 18:05:36 +01:00
drm_auth.c drm: Move piles of functions from drmP.h to drm_internal.h 2014-09-12 11:16:29 +02:00
drm_bufs.c drm: Move __drm_pci_free to drm_legacy.h 2014-09-12 11:08:56 +02:00
drm_cache.c
drm_context.c drm: mark drm_context support as legacy 2014-08-05 19:38:12 +02:00
drm_crtc_helper.c
drm_crtc_internal.h
drm_crtc.c drm: Drop grab fpriv->fbs_lock in drm_fb_release 2014-09-25 17:13:40 +02:00
drm_debugfs.c drm: Move piles of functions from drmP.h to drm_internal.h 2014-09-12 11:16:29 +02:00
drm_dma.c drm: Move legacy buffer structures to <drm/drm_legacy.h> 2014-09-12 15:28:12 +02:00
drm_dp_helper.c
drm_dp_mst_topology.c drm/mst: rework payload table allocation to conform better. 2014-10-13 14:40:53 +10:00
drm_drv.c drm/core: use helper to check driver features 2014-10-03 10:38:56 +02:00
drm_edid_load.c
drm_edid.c drm/edid: Add missing interlaced flag to 576i@100 modes. 2014-10-01 11:36:20 +02:00
drm_encoder_slave.c
drm_fb_cma_helper.c
drm_fb_helper.c Merge tag 'drm-intel-next-2014-09-01' of git://anongit.freedesktop.org/drm-intel into drm-next 2014-09-03 08:30:48 +10:00
drm_flip_work.c
drm_fops.c drm/core: use helper to check driver features 2014-10-03 10:38:56 +02:00
drm_gem_cma_helper.c drm: Pass dma-buf as argument to gem_prime_import_sg_table 2014-09-30 14:04:00 +02:00
drm_gem.c drm/core: use helper to check driver features 2014-10-03 10:38:56 +02:00
drm_global.c
drm_hashtab.c list: fix order of arguments for hlist_add_after(_rcu) 2014-08-06 18:01:24 -07:00
drm_info.c drm: Extract <drm/drm_gem.h> 2014-09-24 11:43:41 +10:00
drm_internal.h drm: Move internal debugfs functions to drm_internal.h 2014-09-24 11:43:35 +10:00
drm_ioc32.c
drm_ioctl.c drm: Purge ioctl forward declarations from drmP.h 2014-09-12 15:27:47 +02:00
drm_irq.c drm: Improve debug output for drm_wait_one_vblank 2014-09-24 12:09:23 +02:00
drm_legacy.h drm: Create drm legacy driver header 2014-09-12 11:08:55 +02:00
drm_lock.c drm: unexport drm_global_mutex 2014-09-12 11:19:47 +02:00
drm_memory.c drm: Move drm_memory.c map support declarations to <drm/drm_legacy.h> 2014-09-12 15:28:12 +02:00
drm_mipi_dsi.c drm/mipi-dsi: consider low power transmission 2014-09-20 00:56:08 +09:00
drm_mm.c
drm_modes.c drm: Perform cmdline mode parsing during connector initialisation 2014-08-06 14:50:12 +02:00
drm_modeset_lock.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-10-14 09:39:08 +02:00
drm_of.c
drm_panel.c
drm_pci.c drm: Move legacy buffer structures to <drm/drm_legacy.h> 2014-09-12 15:28:12 +02:00
drm_plane_helper.c
drm_platform.c drm: Goody bye, drm_bus! 2014-09-10 17:43:10 +10:00
drm_prime.c drm: Pass dma-buf as argument to gem_prime_import_sg_table 2014-09-30 14:04:00 +02:00
drm_probe_helper.c drm: Perform cmdline mode parsing during connector initialisation 2014-08-06 14:50:12 +02:00
drm_rect.c
drm_scatter.c drm: Move sg functions into drm_legacy.h 2014-09-12 11:08:54 +02:00
drm_sysfs.c drm: Move piles of functions from drmP.h to drm_internal.h 2014-09-12 11:16:29 +02:00
drm_trace_points.c
drm_trace.h
drm_vm.c drm: Move drm_vm_open_locked into drm_internal.h 2014-09-24 11:43:20 +10:00
drm_vma_manager.c
Kconfig drm: merge drm_usb into udl 2014-09-10 17:43:27 +10:00
Makefile drm: Add atomic/plane helpers 2014-11-05 18:07:01 +01:00
README.drm

************************************************************
* For the very latest on DRI development, please see:      *
*     http://dri.freedesktop.org/                          *
************************************************************

The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).

The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:

    1. The DRM provides synchronized access to the graphics hardware via
       the use of an optimized two-tiered lock.

    2. The DRM enforces the DRI security policy for access to the graphics
       hardware by only allowing authenticated X11 clients access to
       restricted regions of memory.

    3. The DRM provides a generic DMA engine, complete with multiple
       queues and the ability to detect the need for an OpenGL context
       switch.

    4. The DRM is extensible via the use of small device-specific modules
       that rely extensively on the API exported by the DRM module.


Documentation on the DRI is available from:
    http://dri.freedesktop.org/wiki/Documentation
    http://sourceforge.net/project/showfiles.php?group_id=387
    http://dri.sourceforge.net/doc/

For specific information about kernel-level support, see:

    The Direct Rendering Manager, Kernel Support for the Direct Rendering
    Infrastructure
    http://dri.sourceforge.net/doc/drm_low_level.html

    Hardware Locking for the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/hardware_locking_low_level.html

    A Security Analysis of the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/security_low_level.html