linux/drivers/gpu/drm
Daniel Vetter bfb899282f drm: only take the crtc lock for ->cursor_set
First convert ->cursor_set to only take the crtc lock, since that
seems to be the function with the least amount of state - the core
ioctl function doesn't check anything which can change at runtime, so
we don't have any object lifetime issues to contend.

The only thing which is important is that the driver's implementation
doesn't touch any state outside of that single crtc which is not yet
properly protected by other locking:

- ast: access the global ast->cache_kmap. Luckily we only have on crtc
  on this driver, so this is fine. Add a comment.

- gma500: calls gma_power_begin|and and psb_gtt_pin|unpin, both which
  have their own locking to protect their state. Everything else is
  crtc-local.

- i915: touches a bit of global gem state, all protected by the One
  Lock to Rule Them All (dev->struct_mutex).

- nouveau: Pre-nv50 is all nice, nv50+ uses the evo channels to queue
  up all display changes. And some of these channels are device
  global. But this is fine now since the previous patch introduced an
  evo channel mutex.

- radeon: Uses some indirect register access for cursor updates, but
  with the previous patches to protect these indirect 2-register
  access patterns with a spinlock, this should be fine now, too.

- vmwgfx: I have no idea how that works - update_cursor_position
  doesn't take any per-crtc argument and I haven't figured out any
  other place where this could be set in some form of a side-channel.
  But vmwgfx definitely has more than one crtc (or at least can
  register more than one), so I have no idea how this is supposed to
  not fail with the current code already. Hence take the easy way out
  and simply acquire all locks (which requires dropping the crtc lock
  the core acquired for us). That way it's not worse off for
  consistency than the old code.

Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-01-20 22:16:55 +01:00
..
ast drm: only take the crtc lock for ->cursor_set 2013-01-20 22:16:55 +01:00
cirrus drm/<drivers>: Unified handling of unimplemented fb->create_handle 2013-01-20 15:57:57 +01:00
exynos Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux 2013-01-08 16:08:10 -08:00
gma500 drm/gma500: use drm_modeset_lock_all 2013-01-20 22:16:49 +01:00
i2c drm: encapsulate crtc->set_config calls 2013-01-20 15:57:58 +01:00
i810 UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
i915 drm/i915: use drm_modeset_lock_all 2013-01-20 22:16:47 +01:00
mga UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
mgag200 drm/<drivers>: Unified handling of unimplemented fb->create_handle 2013-01-20 15:57:57 +01:00
nouveau drm: encapsulate crtc->set_config calls 2013-01-20 15:57:58 +01:00
r128 UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
radeon drm/<drivers>: reorder framebuffer init sequence 2013-01-20 15:29:24 +01:00
savage Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2012-10-03 23:29:23 -07:00
shmobile drm/shmobile: use drm_modeset_lock_all 2013-01-20 22:16:51 +01:00
sis UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
tdfx UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
tegra Revert "drm: tegra: protect DC register access with mutex" 2012-12-30 21:58:20 +10:00
ttm drm/ttm: fix fence locking in ttm_buffer_object_transfer 2013-01-08 18:35:31 +10:00
udl drm/<drivers>: Unified handling of unimplemented fb->create_handle 2013-01-20 15:57:57 +01:00
via UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
vmwgfx drm: only take the crtc lock for ->cursor_set 2013-01-20 22:16:55 +01:00
ati_pcigart.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_agpsupport.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_auth.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_buffer.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_bufs.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_cache.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2012-10-03 23:29:23 -07:00
drm_context.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_crtc_helper.c drm: add drm_modeset_lock|unlock_all 2013-01-20 22:16:38 +01:00
drm_crtc.c drm: only take the crtc lock for ->cursor_set 2013-01-20 22:16:55 +01:00
drm_debugfs.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_dma.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_dp_helper.c drm/doc: add new dp helpers into drm DocBook 2012-11-28 20:26:53 +10:00
drm_drv.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2012-10-03 23:29:23 -07:00
drm_edid_load.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2012-10-03 23:29:23 -07:00
drm_edid_modes.h Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2012-10-03 23:29:23 -07:00
drm_edid.c Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel into drm-next 2012-12-16 06:05:03 +00:00
drm_encoder_slave.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_fb_cma_helper.c drm/<drivers>: reorder framebuffer init sequence 2013-01-20 15:29:24 +01:00
drm_fb_helper.c drm: add drm_modeset_lock|unlock_all 2013-01-20 22:16:38 +01:00
drm_fops.c drm: set dev_mapping before calling drm_open_helper 2012-11-07 10:51:15 +10:00
drm_gem_cma_helper.c DRM: Add DRM GEM CMA helper 2012-09-18 12:28:21 +02:00
drm_gem.c mm: kill vma flag VM_RESERVED and mm->reserved_vm counter 2012-10-09 16:22:19 +09:00
drm_global.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_hashtab.c drm: Add a hash-tab rcu-safe API 2012-11-28 18:36:05 +10:00
drm_info.c drm/debugfs: remove redundant info from gem_names 2012-10-23 10:15:04 +10:00
drm_ioc32.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_ioctl.c drm: add support for monotonic vblank timestamps 2012-11-20 16:06:16 +10:00
drm_irq.c drm: hold event_lock while accessing vblank_event_list 2012-11-29 03:30:34 -08:00
drm_lock.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_memory.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_mm.c drm: Only evict the blocks required to create the requested hole 2013-01-08 11:52:02 +01:00
drm_modes.c drm: Constify some function arguments 2012-11-07 10:09:16 +10:00
drm_pci.c drm/pci: add missing variable initialization 2012-11-29 18:20:31 +10:00
drm_platform.c drm: platform: Don't initialize driver-private data 2012-10-23 10:15:11 +10:00
drm_prime.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_proc.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_scatter.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_stub.c drm: add support for monotonic vblank timestamps 2012-11-20 16:06:16 +10:00
drm_sysfs.c drm: remove legacy drm_connector_property fxns 2012-11-30 10:30:48 -06:00
drm_trace_points.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_trace.h
drm_usb.c UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/ 2012-10-02 18:01:07 +01:00
drm_vm.c mm: kill vma flag VM_RESERVED and mm->reserved_vm counter 2012-10-09 16:22:19 +09:00
Kconfig drm: Add NVIDIA Tegra20 support 2012-11-20 15:43:41 +10:00
Makefile drm: only build ati_pcigart if PCI enabled 2012-11-28 20:12:29 +10:00
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