Fix spelling typo in DocBook/drm.tmpl
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is leftover stuff from my previous doc round which I kinda wanted
to do but didn't yet due to rebase hell.

The modeset helpers and the probing helpers a independent and e.g.
i915 uses the probing stuff but has its own modeset infrastructure. It
hence makes to split this up. While at it add a DOC: comment for the
probing libraray.

It would be rather neat to pull some of the DocBook documenting these
two helpers into in-line DOC: comments. But unfortunately kerneldoc
doesn't support markdown or something similar to make nice-looking
documentation, so the current state is better.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>

Oops. This is a regression from

commit 5d7a9515
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Jan 4 22:31:20 2013 +0100

    drm/doc: updates for new framebuffer lifetime rules
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- Tune down yelling RETURNS.
- OCD align all the parameters the same.
- Add missing kerneldoc, which also means that we need to include the
  kerneldoc from the drm_modes.h header now.
- Add missing Returns: sections.
- General polish and clarification - especially the kerneldoc for the
  mode creation helpers seems to have been some good specimen of
  copypasta gone wrong.

All actual code changes have all been extracted into prep patches
since there was simply too much to polish.

v2: More polish for the command line modeline functions.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And clean it up so that there's no kerneldoc warnings. There's still a
lot to do with this one here.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

While at it do a tiny bit of interface cleanup and convert boolean
return values to bool. With this patch all exported functions and inline
helpers which are part of the drm_mm public interface are documented.

Also drop superflous extern function modifiers since most of drm_mm.h
doesn't use them - more consistent that way.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

kerneldoc polish will follow in the next patch.

Hopefully documenting the lru scan support a bit better spurs someone
to give this a shot in the ttm eviction code. At least in i915 it
helped quite a lot with memory thrashing on platforms where eviction
was (we've fixed that too meanwhile) fairly expensive.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I've done quite a bit of cleanups, clarifications and mostly
integrating kerneldoc. So I guess I should add myself.

Also split up the copyright notices per holder to make it clear which
year ranges are covered.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For giant hilarity the DocBook reference overview is only generated
when in a level 2 section, not in a level 3 section. So we need to
move this up a bit as a side-by-side section to the main PRIME
documentation.

Whatever.

To have a complete set of references add the missing kerneldoc for all
functions exported to modules with the exception of the file private
init/destroy functions - drivers have no business calling those, so
let's just drop the EXPORT_SYMBOL instead.

Also reflow the function parameters to align correctly and break at 80
chars - my OCD couldn't stand them while writing the kerneldoc ;-)
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

PRIME fds aren't actually GEM fds but are (like the modeset API)
independent of the underlying buffer manager, as long as that one uses
uint32_t as handles. So move that entire section out of the GEM
section and reword it a bit to clarify which parts of PRIME are
generic, and which are the mandatory pieces for GEM drivers to
correctly implement the GEM lifetime rules. The rewording mostly
consists of not mixing up GEM, PRIME and DRM.

I've considered adding some blurbs to the GEM object lifetime section
about interactions with dma-bufs, but then dropped that. As long as
drivers use the right helpers they should have this all implemented
correctly and hence can be regarded as an implementation detail of the
PRIME/GEM helpers. So no need to confuse driver writers with those
tricky interactions.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Thierry created such nice kerneldocs, it's a shame we've left them
lingering!

For the fun of it also add a bit of kerneldoc to the header so that we
can also include that. Just in case someone adds kerneldoc in there.

Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

By consolidating them all into one section at the very end. And to
make double-sure that no one gets confused start with a stern warning
against any use of them. And prefix all subsections with "Legacy".
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Stumbled over while reviewing all occurences in the DRM doc talking
about suspend/resume.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Those all died with

commit 0111be42
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Fri Oct 4 14:53:41 2013 +0300

    drm: Kill drm perf counter leftovers
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This should be done in the driver chapter instead.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently it's sitting in the mode setting helper section, which isn't
quite right. Looks much better in the memory management section next
to TTM and GEM.

Cc: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Split up the DocBook into the core drm part and a 2nd part for
driver documentation. As an example add a very (very!) basic
skeleton for i915.

v1: Typo fixes from Dieter.

Cc: Dieter Nützel <Dieter@nuetzel-hh.de>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The stylesheet doesn't allow this in normal paragraphs.

Cc: David Herrmann <dh.herrmann@gmail.com>
Acked-by: NDavid Herrmann <dh.herrmann@gmail.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fairly incomplete, but at least a start.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- This is _not_ a generic interface to create gem objects, but just an
  interface to make early boot services (like boot splash) with a
  generic KMS userspace driver possible. Hence it's better to move
  the documentation for this from the GEM section to the KMS section,
  next to the creation of framebuffer objects.

- Make it really clear that the returned handle isn't necessarily a
  GEM object (it can also be e.g. a TTM handle when running on top of
  vmwgfx).

- Add a paragraph to make it clear that this is just for unaccelarated
  userspace - gpu drivers need to have their own buffer object
  creation ioctl which is hardware specific.

v2: Clarify that the documentation doesn't just apply to GEM-based
drivers only but is now generally valid, as suggested by David.

v3: Polish the intro sentence a bit and one s/objects/handles/ for
clarification, both suggested by Laurent.

v4: More text polish from Laurent's review.

v5: More typo fixes from Dieter.

Cc: Dieter Nützel <Dieter@nuetzel-hh.de>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Render nodes provide an API for userspace to use non-privileged GPU
commands without any running DRM-Master. It is useful for offscreen
rendering, GPGPU clients, and normal render clients which do not perform
modesetting.

Compared to legacy clients, render clients no longer need any
authentication to perform client ioctls. Instead, user-space controls
render/client access to GPUs via filesystem access-modes on the
render-node. Once a render-node was opened, a client has full access to
the client/render operations on the GPU. However, no modesetting or ioctls
that affect global state are allowed on render nodes.

To prevent privilege-escalation, drivers must explicitly state that they
support render nodes. They must mark their render-only ioctls as
DRM_RENDER_ALLOW so render clients can use them. Furthermore, they must
support clients without any attached master.

If filesystem access-modes are not enough for fine-grained access control
to render nodes (very unlikely, considering the versaitlity of FS-ACLs),
you may still fall-back to fd-passing from server to client (which allows
arbitrary access-control). However, note that revoking access is
currently impossible and unlikely to get implemented.

Note: Render clients no longer have any associated DRM-Master as they are
supposed to be independent of any server state. DRM core highly depends on
file_priv->master to be non-NULL for modesetting/ctx/etc. commands.
Therefore, drivers must be very careful to not require DRM-Master if they
support DRIVER_RENDER.

So far render-nodes are protected by "drm_rnodes". As long as this
module-parameter is not set to 1, a driver will not create render nodes.
This allows us to experiment with the API a bit before we stabilize it.

v2: drop insecure GEM_FLINK to force use of dmabuf
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

It has way too much potential for driver writers to do stupid things
like delayed hw setup because the load sequence is somehow racy (e.g.
the imx driver in staging). So don't call it for modesetting drivers,
which reduces the complexity of the drm core -> driver interface a
notch.

v2: Don't forget to update DocBook.

v3: Go with Laurent's slightly more elaborate proposal for the DocBook
update. Add a few words on top of his diff to elaborate a bit on what
KMS drivers should and shouldn't do in lastclose. There was already a
paragraph present talking about restoring properties, I've simply
extended that one.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

I've forgotten this and shuffling all the little pieces into the
respective patches is rather cumbersome ...
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

A small helper to queue up work to do, from workqueue context, after a
flip.  Typically useful to defer unreffing buffers that may be read by
the display controller until vblank.

v1: original
v2: wire up docbook + couple docbook fixes
Signed-off-by: NRob Clark <robdclark@gmail.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

So I've stumbled over drm_fasync and wondered what it does. Digging
that up is quite a story.

First I've had to read up on what this does and ended up being rather
bewildered why peopled loved signals so much back in the days that
they've created SIGIO just for that ...

Then I wondered how this ever works, and what that strange "No-op."
comment right above it should mean. After all calling the core fasync
helper is pretty obviously not a noop. After reading through the
kernels FASYNC implementation I've noticed that signals are only sent
out to the processes attached with FASYNC by calling kill_fasync.

No merged drm driver has ever done that.

After more digging I've found out that the only driver that ever used
this is the so called GAMMA driver. I've frankly never heard of such a
gpu brand ever before. Now FASYNC seems to not have been the only bad
thing with that driver, since Dave Airlie removed it from the drm
driver with prejudice:

commit 1430163b4bbf7b00367ea1066c1c5fe85dbeefed
Author: Dave Airlie <airlied@linux.ie>
Date:   Sun Aug 29 12:04:35 2004 +0000

    Drop GAMMA DRM from a great height ...

Long story short, the drm fasync support seems to be doing absolutely
nothing. And the only user of it was never merged into the upstream
kernel. And we don't need any fops->fasync callback since the fcntl
implementation in the kernel already implements the noop case
correctly.

So stop this particular cargo-cult and rip it all out.

v2: Kill drm_fasync assignments in rcar (newly added) and imx drivers
(somehow I've missed that one in staging). Also drop the reference in
the drm DocBook. ARM compile-fail reported by Rob Clark.

v3: Move the removal of dev->buf_asnyc assignment in drm_setup to this
patch here.

v4: Actually git add ... tsk.

Cc: Dave Airlie <airlied@linux.ie>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Rob Clark <robdclark@gmail.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

If we want to map GPU memory into user-space, we need to linearize the
addresses to not confuse mm-core. Currently, GEM and TTM both implement
their own offset-managers to assign a pgoff to each object for user-space
CPU access. GEM uses a hash-table, TTM uses an rbtree.

This patch provides a unified implementation that can be used to replace
both. TTM allows partial mmaps with a given offset, so we cannot use
hashtables as the start address may not be known at mmap time. Hence, we
use the rbtree-implementation of TTM.

We could easily update drm_mm to use an rbtree instead of a linked list
for it's object list and thus drop the rbtree from the vma-manager.
However, this would slow down drm_mm object allocation for all other
use-cases (rbtree insertion) and add another 4-8 bytes to each mm node.
Hence, use the separate tree but allow for later migration.

This is a rewrite of the 2012-proposal by David Airlie <airlied@linux.ie>

v2:
 - fix Docbook integration
 - drop drm_mm_node_linked() and use drm_mm_node_allocated()
 - remove unjustified likely/unlikely usage (but keep for rbtree paths)
 - remove BUG_ON() as drm_mm already does that
 - clarify page-based vs. byte-based addresses
 - use drm_vma_node_reset() for initialization, too
v4:
 - allow external locking via drm_vma_offset_un/lock_lookup()
 - add locked lookup helper drm_vma_offset_lookup_locked()
v5:
 - fix drm_vma_offset_lookup() to correctly validate range-mismatches
   (fix (offset > start + pages))
 - fix drm_vma_offset_exact_lookup() to actually do what it says
 - remove redundant vm_pages member (add drm_vma_node_size() helper)
 - remove unneeded goto
 - fix documentation
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@gmail.com>

Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

The i915 driver has been fixed not to modify the mode argument of the
encoder mode_fixup operation. Remove the related comment from the
documentation.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Define the rules for using irqs from drm drivers.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NAnatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The 'struct' keyword was missing so struct drm_rect documentation never
ended up in the generated docs.

Also move the drm_rect documentations to a new section alognside the
various helper functions and add a short description about the intended
purpose of drm_rect.

v2: Move to new section and add general description
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

struct drm_rect represents a simple rectangle. The utility
functions are there to help driver writers.

v2: Moved the region stuff into its own file, made the smaller funcs
    static inline, used 64bit maths in the scaled clipping function to
    avoid overflows (instead it will saturate to INT_MIN or INT_MAX).
v3: Renamed drm_region to drm_rect, drm_region_clip to
    drm_rect_intersect, and drm_region_subsample to drm_rect_downscale.
v4: Renamed some function parameters, improve kernel-doc comments a bit,
    and actually generate documentation for drm_rect.[ch].
v5: s/RETUTRNS/RETURNS/
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Driver implementations of the drm_crtc's .page_flip() function are
required to update the crtc->fb field on success to reflect that the new
framebuffer is now in use. This is important to keep reference counting
on the framebuffers balanced.

While at it, document this requirement to keep others from falling into
the same trap.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add a reference section about the EDID helper functions to the DRM
documentation.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>

Now that the fbdev helper interface for drivers is trimmed down,
update the kerneldoc for all the remaining exported functions.

I've tried to beat the DocBook a bit by reordering the function
references a bit into a more sensible ordering. But that didn't work
out at all. Hence just extend the in-code DOC: section a bit.

Also remove the LOCKING: sections - especially for the setup functions
they're totally bogus. But that's not a documentation problem, but
simply an artifact of the current rather hazardous locking around drm
init and even more so around fbdev setup ...

v2: Some further improvements:
- Also add documentation for drm_fb_helper_single_add_all_connectors,
  Dave Airlie didn't want me to kill this one from the fb helper
  interface.
- Update docs for drm_fb_helper_fill_var/fix - they should be used
  from the driver's ->fb_probe callback to setup the fbdev info
  structure.
- Clarify what the ->fb_probe callback should all do - it needs to
  setup both the fbdev info and allocate the drm framebuffer used as
  backing storage.
- Add basic documentaation for the drm_fb_helper_funcs driver callback
  vfunc.

v3: Implement clarifications Laurent Pinchart suggested in his review.

v4: Fix another mispelling Laurent spotted.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Instead of reimplementing all of the dma_buf functionality in every driver,
create helpers drm_prime_import and drm_prime_export that implement them in
terms of new, lower-level hook functions:

  gem_prime_pin: callback when a buffer is created, used to pin buffers into GTT
  gem_prime_get_sg_table: convert a drm_gem_object to an sg_table for export
  gem_prime_import_sg_table: convert an sg_table into a drm_gem_object
  gem_prime_vmap, gem_prime_vunmap: map and unmap an object

These hooks are optional; drivers can opt in by using drm_gem_prime_import and
drm_gem_prime_export as the .gem_prime_import and .gem_prime_export fields of
struct drm_driver.

v2:
- Drop .begin_cpu_access.  None of the drivers this code replaces implemented
  it.  Having it here was a leftover from when I was trying to include i915 in
  this rework.
- Use mutex_lock instead of mutex_lock_interruptible, as these three drivers
  did.  This patch series shouldn't change that behavior.
- Rename helpers to gem_prime_get_sg_table and gem_prime_import_sg_table.
  Rename struct sg_table* variables to 'sgt' for clarity.
- Update drm.tmpl for these new hooks.

v3:
- Pass the vaddr down to the driver.  This lets drivers that just call vunmap on
  the pointer avoid having to store the pointer in their GEM private structures.
- Move documentation into a /** DOC */ comment in drm_prime.c and include it in
  drm.tmpl with a !P line.  I tried to use !F lines to include documentation of
  the individual functions from drmP.h, but the docproc / kernel-doc scripts
  barf on that file, so hopefully this is good enough for now.
- apply refcount fix from commit be8a42ae
  ("drm/prime: drop reference on imported dma-buf come from gem")
Signed-off-by: NAaron Plattner <aplattner@nvidia.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Now that framebuffer are reference-counted for all use-sites, update
the documentation accordingly to stress the new rules for
initialization and teardown.

Also add a short paragraph about the implications for drivers of the
new locking rules.
Reviewed-by: NRob Clark <rob@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And do a quick pass to adjust them to the last few (years?) of changes
...

This time actually compile-tested ;-)
Reviewed-by: NRob Clark <rob@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I didn't bother with documenting the really trivial new "extract
something from dpcd" helpers, but the i2c over aux ch is now
documented a bit.

v2: Clarify the comment for i2c_dp_aux_add_bus a bit.

v3: Fix more spelling fail spotted by Laurent Pinchart.
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>