Compared to wrapping the final kref_put with dev->struct_mutex this
allows us to only acquire the offset manager look both in the final
cleanup and in the lookup. Which has the upside that no locks leak out
of the core abstractions. But it means that we need to hold a
temporary reference to the object while checking mmap constraints, to
make sure the object doesn't disappear. Extended the critical region
would have worked too, but would result in more leaky locking.

Also, this is the final bit which required dev->struct_mutex in gem
core, now modern drivers can be completely struct_mutex free!

This needs a new drm_vma_offset_exact_lookup_locked and makes both
drm_vma_offset_exact_lookup and drm_vma_offset_lookup unused.

v2: Don't leak object references in failure paths (David).

v3: Add a comment from Chris explaining how the ordering works, with
the slight adjustment that I dropped any mention of struct_mutex since
with this patch it's now immaterial ot core gem.

Cc: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://mid.gmane.org/1444901623-18918-1-git-send-email-daniel.vetter@ffwll.chSigned-off-by: Daniel Vetter <daniel.vetter@intel.com>

It's duplicating (without using some of the helpers) drm_gem_mmap with
the addition that it can redirect to drm-buf mmap support. But prime
import/export was dropped in

commit 990ed272
Author: Rob Clark <robdclark@gmail.com>
Date:   Thu May 21 11:58:30 2015 -0400

    drm/vgem: drop DRIVER_PRIME (v2)

for now, so this is dead code. And since I want to rework the locking
for drm_gem_mmap it seems simpler to de-dupe this code for now and
then start over with the reworked one again, if we want to resurrect
this all indeed.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://mid.gmane.org/1444894601-5200-8-git-send-email-daniel.vetter@ffwll.chAcked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

In its original version, drm_framebuffer_init() returned a negative int
if drm_mode_object_get() failed (f453ba04, "DRM: add mode setting
support").

This was accidentally disabled by commit 4b096ac1 ("drm: revamp
locking around fb creation/destruction"). Thus, drm_framebuffer_init()
pretends success if drm_mode_object_get() failed.

Reinstate the original behaviour. Also fix erroneous kernel-doc of
drm_mode_object_get().

Fixes: 4b096ac1 ("drm: revamp locking around fb creation/
    destruction")
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Just a random thing I spotted while reading code - better safe than
sorry.

Link: http://mid.gmane.org/1444894601-5200-11-git-send-email-daniel.vetter@ffwll.chReviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

Pretty soon only some drivers will need dev->struct_mutex in their
gem_free_object callbacks. Hence it's really important to make sure
everything still keeps getting this right.

v2: Don't check for locking before we check for non-NULL obj. Spotted
by Dan Carpenter.

Link: http://mid.gmane.org/1444894601-5200-10-git-send-email-daniel.vetter@ffwll.chReviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

Since

commit 131e663b
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jul 9 23:32:33 2015 +0200

    drm/gem: rip out drm vma accounting for gem mmaps

there is no need for this any more.

v2: Fixup compile noise spotted by 0-day build.

Link: http://mid.gmane.org/1444894601-5200-9-git-send-email-daniel.vetter@ffwll.chReviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

Fixes userspace compilation error:

error: array type has incomplete element type
struct drm_clip_rect boxes[I810_NR_SAREA_CLIPRECTS];
Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Fixes compile error:

drm/r128_drm.h:156:23: error: array type has incomplete element type
  struct drm_clip_rect boxes[R128_NR_SAREA_CLIPRECTS];
Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Fixes compiler error:

drm/savage_drm.h:50:24: error: array type has incomplete element type
  struct drm_tex_region texList[SAVAGE_NR_TEX_HEAPS][SAVAGE_NR_TEX_REGIONS +
Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

This snippet...

    * Lock VMA manager for extended lookups. Only *_locked() VMA function calls
    * are allowed while holding this lock. All other contexts are blocked from VMA
    * until the lock is released via drm_vma_offset_unlock_lookup().

...causes markdown-enabled kernel-doc to barf:

    debian/build/build-doc/Documentation/DocBook/gpu.aux.xml:3247: parser error : Opening and ending tag mismatch: emphasis line 3247 and function
       *<function><emphasis>locked</function> VMA function calls are allowed while
                                             ^
    /root/airlied/debian/build/build-doc/Documentation/DocBook/gpu.aux.xml:3249: parser error : Opening and ending tag mismatch: function line 3249 and emphasis
       released via <function>drm</emphasis>vma_offset_unlock_lookup</function>.
                                            ^
    unable to parse /root/airlied/debian/build/build-doc/Documentation/DocBook/gpu.aux.xml

A quick workaround is to replace *_locked() by X_locked().

Cc: Danilo Cesar Lemes de Paula <danilo.cesar@collabora.co.uk>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
[danvet: Just drop the X_ too, the usual style is _unlocked, except
that _ seems to be what annoys markdown.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Requires Markdown support.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Following Daniel's renaming of the document.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

DRM is a lot more than a direct rendering manager nowadays, and there's
also a bunch of things worth documenting for gpu driver developers
outside of drivers/gpu/drm, like vgaarb, vga_switcheroo or the various
hardware buses like host1x and ipu-v3.

To avoid further confusion let's rename the top-level to reflect
reality.

And yes I'm already looking forward to when we need to replace the G
in GPU with a * ;-)

Inspired by a thread with Lukas since he refused to include the
vga_switcheroo docs into the drm docs because it's not drm.

Cc: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
[Lukas: Drop BUG() easter egg in i915_gem_execbuffer.c spotted by Jani
and fix typos in commit message.]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Drop unused drm_atomic and fix comment for drm_debug.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Add a new debug class for _verbose_ debug message from the vblank code.
That is message we spew out potentially for every vblank interrupt.
Thierry already got annoyed at the spew, and now I managed to lock up
my box with these debug prints (seems serial console + a few debug
prints every vblank aren't a good combination).

Or should I maybe call it DRM_DEBUG_IRQ?

Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

String literals get concatenated just fine on their own,
no need to use '\'.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Just one special case (since i915 lost its ums code, yay):
- radeon: Has slots for the old ums ioctls which don't have
  DRM_UNLOCKED, but all filled with drm_invalid_op. So ok to drop it
  everywhere.

Every other kms driver just has DRM_UNLOCKED for all their ioctls, as
they should.

v2: admgpu happened, include that one too. And i915 lost its UMS
support which means we can change all the i915 ioctls too.

v3: Rebased on top of new vmwgfx DX interface extensions.

v4: Rebase on top of render-node support in exynos.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

With the prep patches for i915 all kms drivers either have
DRM_UNLOCKED on all their ioctls. Or the ioctl always directly returns
with an invariant return value when in modeset mode. But that's only
the case for i915 and radeon. The drm core ioctls are unfortunately
too much a mess still to dare this.

Follow-up patches will remove DRM_UNLOCKED from all kms drivers to
prove that this is indeed the case.

Also update the documentation.

v2: Really only do this for driver ioctls, spotted by David Herrmann.
And drop spurious whitespace change.

Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

With kms all the data getparam looks at is actually invariant, and
certainly not protected by the global kms mutex. With ums all the
setup code is already racy as hell, so this won't make things any
worse.

I've done this change so that all ioctl still used by kms drivers
are marked as DRM_UNLOCKED, besides that we obviously don't need
it any more in kms mode.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drm_vblank_count() returns the software counter. We should not pretend
it's the hw counter since we use the hw counter to figuere out what the
software counter value should be. So instead provide a new function
drm_vblank_no_hw_counter() for drivers that don't have a real hw
counter. The new function simply returns 0, which is about the only
thing it can do.

Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Vincent Abriou <vincent.abriou@st.com>
[danvet: s/int pipe/unsigned int pipe/ to follow Thierry's interface
change.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

This continues the pattern started in commit cc1ef118 ("drm/irq:
Make pipe unsigned and name consistent"). This is applied to the public
APIs and driver callbacks, so pretty much all drivers need to be updated
to match the new prototypes.

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Jianwei Wang <jianwei.wang.chn@gmail.com>
Cc: Alison Wang <alison.wang@freescale.com>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mark Yao <mark.yao@rock-chips.com>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Avoid magic numbers and use the introduced defines.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Makes it cleaner to separate the two from rotation variable.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The following functions iterate over the client list, invoke client
callbacks or invoke handler callbacks without locking anything at all:

- Introduced by c8e9cf7b ("vga_switcheroo: Add a helper function to
  get the client state"):
  vga_switcheroo_get_client_state()

- Introduced by 0d69704a ("gpu/vga_switcheroo: add driver control
  power feature. (v3)"):
  vga_switcheroo_set_dynamic_switch()
  vga_switcheroo_runtime_suspend()
  vga_switcheroo_runtime_resume()
  vga_switcheroo_runtime_resume_hdmi_audio()

Refactor vga_switcheroo_runtime_resume_hdmi_audio() a bit to be able to
release vgasr_mutex immediately after iterating over the client list.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

If we couldn't get a high precisions vblank timestamp, we currently
store a zeroed timestamp instead and assume the next vblank irq to
get us something better. This makes sense when trying to update the
timestamp from eg. vblank enable. But if we do this from the vblank
irq we will never get a vblank timestamp unless we high precision
timestamps are available and succeeded. This break weston for instance
on drivers lacking high precision timestamps.

To fix this, zero the timestamp only when not called from vbl irq.
When called from the irq, we still want the timestamp, even if not
perfect.

This fixes a regression from
4dfd6486 drm: Use vblank timestamps to guesstimate how many vblanks were missed

Cc: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Reported-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Surprisingly kbuild can't cope with tristates in the
<module>-$(CONFIG_FOO) pattern. This patch hacks up a solution.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Michal Marek <mmarek@suse.com>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

This was only used for the ums+gem combo, so ripe for removal now that
we only have kms code left.

v2: Drop fence_reg_start since it's now unused, noticed by Ville.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

They're only used in the drm ioctl table, and there they're excluded
when AGP support is disabled. So this is just dead code ripe for
removal.
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

drm core enforces now for DRIVER_MODESET that all ioctls are unlocked.
And all the old nasty ones from drm core aren't allowed for modern
drivers any more. Hence this is no longer needed.
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

As usual pull it into the drm docbook template, too. And again as
usual I've decided to only document stuff exported to drivers, so all
the old leftover markup from the shared drm repo days lost the magic
** signature.
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

And use it in radeon to replace all the ioctls no longer valid in kms
mode. I plan to also use this later on when nuking the ums support for
i915.

Note that setting the function pointer in the ioctl table to NULL
would amount to the same, but that results in some debug output from
the drm_ioctl() function. I've figured it's cleaner to have a
special-purpose function.

Cc: Alex Deucher <alexdeucher@gmail.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

We already express the drm/agp depencies correctly in Kconfig, so we
can rip this remnant from the shared drm core days.

Aside: Pretty much all the #ifdefs in radeon/nouveau could be killed
if ttm would provide dummy functions. I'm not going to volunteer for
that though.

v2: Use IS_ENABLED(CONFIG_AGP) as suggested by Ville

v3: Polish from Ville's review.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com> (v2)
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

->load is deprecated, bus functions are deprecated and everyone
should use drm_dev_alloc&register.

So update the .tmpl (and pull a bunch of the overview docs into the
sourcecode to increase chances that it'll stay in sync in the future)
and add notes to functions which are deprecated. I didn't bother to
clean up and document the unload sequence similarly since that one is
still a bit a mess: drm_dev_unregister does way too much,
drm_unplug_dev does what _unregister should be doing but then has the
complication of promising something it doesn't actually do (it doesn't
unplug existing open fds for instance, only prevents new ones).

Motivated since I don't want to hunt every new driver for usage of
drm_platform_init any more ;-)

v2: Reword the deprecation note for ->load a bit, using Laurent's
suggestion as an example (but making the wording a bit stronger even).
Fix spelling in commit message.

v3: More spelling fixes from Laurent.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Acked-by: David Herrmann <dh.herrmann@gmail.com> (v2)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Another attempt at drm-misc for 4.4 ...
- better atomic helpers for runtime pm drivers
- atomic fbdev
- dp aux i2c STATUS_UPDATE handling (for short i2c replies from the sink)
- bunch of constify patches
- inital kerneldoc for vga switcheroo
- some vblank code cleanups from Ville and Thierry
- various polish all over

* tag 'topic/drm-misc-2015-09-25' of git://anongit.freedesktop.org/drm-intel: (57 commits)
  drm/irq: Add drm_crtc_vblank_count_and_time()
  drm/irq: Rename drm_crtc -> crtc
  drm: drm_atomic_crtc_get_property should be static
  drm/gma500: Remove DP_LINK_STATUS_SIZE redefinition
  vga_switcheroo: Set active attribute to false for audio clients
  drm/core: Preserve the fb id on close.
  drm/core: Preserve the framebuffer after removing it.
  drm: Use vblank timestamps to guesstimate how many vblanks were missed
  drm: store_vblank() is never called with NULL timestamp
  drm: Clean up drm_calc_vbltimestamp_from_scanoutpos() vbl_status
  drm: Limit the number of .get_vblank_counter() retries
  drm: Pass flags to drm_update_vblank_count()
  drm/i915: Fix vblank count variable types
  drm: Kill pixeldur_ns
  drm: Stop using linedur_ns and pixeldur_ns for vblank timestamps
  drm: Move timestamping constants into drm_vblank_crtc
  drm/fbdev: Update legacy plane->fb refcounting for atomic restore
  drm: fix kernel-doc warnings in drm_crtc.h
  vga_switcheroo: Sort headers alphabetically
  drm: Spell vga_switcheroo consistently
  ...

Pull x86 fixes from Thomas Gleixner:
 "Two bugfixes from Andy addressing at least some of the subtle NMI
  related wreckage which has been reported by Sasha Levin"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/nmi/64: Fix a paravirt stack-clobbering bug in the NMI code
  x86/paravirt: Replace the paravirt nop with a bona fide empty function