Instead of our own duplicated one. This fixes a bug in the driver
unload code if DRM_FBDEV_EMULATION=n but DRM_I915_FBDEV=y because we
try to unregister the nonexistent fbdev drm_framebuffer.

Cc: Archit Taneja <architt@codeaurora.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reported-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Without this when a MST connector is removed drm_atomic_helper_set_config
can complain about set->mode && !set->num_connectors.

------------[ cut here ]------------
WARNING: CPU: 2 PID: 2403 at drivers/gpu/drm/drm_atomic_helper.c:1673 drm_atomic_helper_set_config+0x22e/0x420()
CPU: 2 PID: 2403 Comm: kms_flip Not tainted 4.2.0-rc5 #4233
Hardware name: NUC5i7RYB, BIOS RYBDWi35.86A.0246.2015.0309.1355 03/09/2015
 ffffffff81ac75e8 ffff88004e4ffbf8 ffffffff81714c34 0000000080000000
 0000000000000000 ffff88004e4ffc38 ffffffff8107bf81 ffff88004e4ffc48
 ffff8800d8ca0690 ffff8800d8d7a080 ffff8800d8cc2290 ffff8800d07bc9f0
Call Trace:
 [<ffffffff81714c34>] dump_stack+0x4f/0x7b
 [<ffffffff8107bf81>] warn_slowpath_common+0x81/0xc0
 [<ffffffff8107c065>] warn_slowpath_null+0x15/0x20
 [<ffffffff813d9e3e>] drm_atomic_helper_set_config+0x22e/0x420
 [<ffffffff813da174>] ? drm_atomic_helper_plane_set_property+0x84/0xc0
 [<ffffffff813ee101>] drm_mode_set_config_internal+0x61/0x100
 [<ffffffff813dc4ed>] restore_fbdev_mode+0xbd/0xe0
 [<ffffffff813de1e4>] drm_fb_helper_restore_fbdev_mode_unlocked+0x24/0x70
 [<ffffffffc0123d11>] intel_fbdev_restore_mode+0x21/0x80 [i915]
 [<ffffffffc014bf69>] i915_driver_lastclose+0x9/0x10 [i915]
 [<ffffffff813e2429>] drm_lastclose+0x29/0x130
 [<ffffffff813e2844>] drm_release+0x314/0x500
 [<ffffffff81194795>] __fput+0xe5/0x1f0
 [<ffffffff811948d9>] ____fput+0x9/0x10
 [<ffffffff810968d8>] task_work_run+0x88/0xb0
 [<ffffffff8107d53f>] do_exit+0x37f/0xa90
 [<ffffffff8127e258>] ? selinux_file_ioctl+0x48/0xc0
 [<ffffffff81277dfe>] ? security_file_ioctl+0x3e/0x60
 [<ffffffff8107ec80>] do_group_exit+0x40/0xa0
 [<ffffffff8107ecef>] SyS_exit_group+0xf/0x10
 [<ffffffff8171bdd7>] entry_SYSCALL_64_fastpath+0x12/0x6a
---[ end trace 0daf358c49351567 ]---
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We want to make sure that no one tries to acquire more locks and
states, and ww mutexes provide debug facilities for that. So use them.

v2: Only call acquire_done when ->atomic_check was successful to avoid
falling over an -EDEADLK (spotted by Maarten).

Cc: Rob Clark <robdclark@gmail.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

In

commit 6f75cea6
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Nov 19 18:38:07 2014 +0100

    drm/atomic: Only destroy connector states with connection mutex held

I tried to fix races of atomic commits against connector
hot-unplugging. The idea is to ensure lifetimes by holding the
connection_mutex long enough. That works for synchronous commits, but
not for async ones.

For async atomic commit we really need to fix up connector lifetimes
for real. But that's a much bigger task, so just add more duct-tape:
For cleaning up connector states we currently don't need the connector
itself. So NULL it out and remove the locking check. Of course that
check was to protect the entire sequence, but the modeset itself
should be save since currently DP MST hot-removal does a dpms-off. And
that should synchronize with any outstanding async atomic commit.

Or at least that's my hope, this is all a giant mess.
Reported-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Spotted while reading code for random reasons.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

It really doesn't protect anything which doesn't have other locks
already. It also doesn't seem to be wired up into the driver unload
code fwiw, but that's a different issue.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This is only called in driver load/unload paths, no need to grab any
locks at all. Also, ttm takes care of itself anyway.

Cc: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Since David Herrmann's mmap vma manager rework we don't need to grab
dev->struct_mutex any more to prevent races when looking up the mmap
offset. Drop it and instead don't forget to use the unref_unlocked
variant (since the drm core still cares).

Aside: I stumbled over the mmap handler which directly does a
dma_mmap_attrs. But totally fails to grab a reference on the
underlying object and hence looks like it happily just leaks the ptes
since there's no guarantee the mmap isn't still around when
gem_free_object is called. Which the kerneldoc of dma_mmap_attrs
explicitly forbids.

v2: Fixup compile fail 0-day spotted.

Cc: Mark Yao <mark.yao@rock-chips.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Since David Herrmann's mmap vma manager rework we don't need to grab
dev->struct_mutex any more to prevent races when looking up the mmap
offset. Drop it and instead don't forget to use the unref_unlocked
variant (since the drm core still cares).

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Since David Herrmann's mmap vma manager rework we don't need to grab
dev->struct_mutex any more to prevent races when looking up the mmap
offset. Drop it and instead don't forget to use the unref_unlocked
variant (since the drm core still cares).
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Looking up an obj, immediate dropping the acquired reference and then
continuing to use it isn't how this is supposed to work. Fix this by
holding a reference for the entire function.

While at it stop grabbing dev->struct_mutex, it doesn't protect
anything here.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Since David Herrmann's mmap vma manager rework we don't need to grab
dev->struct_mutex any more to prevent races when looking up the mmap
offset. Drop it and instead don't forget to use the unref_unlocked
variant (since the drm core still cares).
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Since David Herrmann's mmap vma manager rework we don't need to grab
dev->struct_mutex any more to prevent races when looking up the mmap
offset. Drop it and instead don't forget to use the unref_unlocked
variant (since the drm core still cares).
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Since David Herrmann's mmap vma manager rework we don't need to grab
dev->struct_mutex any more to prevent races when looking up the mmap
offset. Drop it and instead don't forget to use the unref_unlocked
variant (since the drm core still cares).
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

BUG_ON kills the driver, WARN_ON is much friendlier. And usually nothing
bad happens when the locking is slightly busted.

v2: Fix typos in commit message Thierry spotted.
Reviewed-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Legacy fbdev emulation support via DRM is achieved through KMS FB helpers.
Most modesetting drivers enable provide fbdev emulation by default by
selecting KMS FB helpers. A few provide a separate Kconfig option for the
user to enable or disbale fbdev emulation.

Enabling fbdev emulation is finally a distro-level decision. Having a top
level Kconfig option for fbdev emulation helps by providing a uniform way
to enable/disable fbdev emulation for any modesetting driver. It also lets
us remove unnecessary driver specific Kconfig options that causes bloat.

With a top level Kconfig in place, we can stub out the fb helper functions
when not needed without breaking functionality. Having stub functions also
prevents drivers to require wrapping fb helper function calls with #ifdefs.

DRM_FBDEV_EMULATION defaults to y since many drivers enable fbdev
emulation by default and majority of distributions expect the fbdev
interface in the kernel.
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If CONFIG_MAGIC_SYSRQ is not set:

    drivers/gpu/drm/drm_fb_helper.c:390:13: warning: 'drm_fb_helper_force_kernel_mode' defined but not used [-Wunused-function]
     static bool drm_fb_helper_force_kernel_mode(void)
		 ^

Move drm_fb_helper_force_kernel_mode() inside the existing #ifdef to fix
this.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As of commit 5ea1f752 ("drm: add
drm_fb_helper_restore_fbdev_mode_unlocked()"),
drm_fb_helper_restore_fbdev_mode() is no longer public, and drivers
should call drm_fb_helper_restore_fbdev_mode_unlocked() from their
->lastclose callbacks instead.

Update the documentation to reflect this, and absorb the one liner
drm_fb_helper_restore_fbdev_mode() into its single caller.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag and there
is no need to do that again from its callers. Drop it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NSinclair Yeh <syeh@vmware.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- add missing header for virtgpu_fb.c

Cc: David Airlie <airlied@linux.ie>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- Fixed PTR_ERR issue mentioned by kbuild bot

Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- remove unused variable device in bochsfb_create

Cc: David Airlie <airlied@linux.ie>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- remove unused variable pdev in nouveau_fbcon_create

Cc: David Airlie <airlied@linux.ie>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- No changes

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- Fix build break because of missing include of drm_fb_helper in
  radeon_drv.c

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- remove unused goto label 'out'

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v3:
- Update error handling for new drm_fb_helper funcs. Check using IS_ERR()
  instead of checking for NULL.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>

v2:
- No changes

Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly.

v3:
- Don't touch remove_conflicting_framebuffers

v2:
- Remove stray goto label out_iounmap

Cc: Thierry Reding <treding@nvidia.com>
Cc: Zach Reizner <zachr@google.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With

commit 7a3f3d66
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jul 9 23:44:28 2015 +0200

    drm: Check locking in drm_for_each_connector

we started checking the locking in drm_for_each_connector but somehow
I totally missed drm_mode_config_reset. There's no problem there since
this function should only be called in single-threaded contexts
(driver load or resume), so just wrap the loop with the right lock.

v2: Drink coffee and all that ...

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reported-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

The last user is gone, no need for trylocking any more in this legacy
helper.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Since the panic handling is gone this is only used for force-restoring
the fbdev/fbcon from sysrq, and that's done with a work item. No need
any more to do trylocks, we can just do normal locking.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Trying to do anything with kms drivers when oopsing has become a
failing proposition. But since we can end up in the fbdev code simply
due to the console unblanking that's done unconditionally just
removing our panic handler isn't enough. We need to block all fbdev
callbacks when oopsing.

There was already one in the blank handler, but it failed silently.
That makes it impossible for drivers (like i915) who subclass these
functions to figure this out.

Instead consistently return -EBUSY so that everyone knows that we
really don't want to be bothered right now. This also allows us to
remove a pile of FIXMEs from the i915 fbdev code (since due to the
failure code they now won't attempt to grab dangerous locks any more).

Cc: Dave Airlie <airlied@gmail.com>
Cc: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v2:
- remove unused variable device in udlfb_create

Cc: David Airlie <airlied@linux.ie>
Cc: Haixia Shi <hshi@chromium.org>
Cc: "Stéphane Marchesin" <marcheu@chromium.org>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

Cc: David Airlie <airlied@linux.ie>
Cc: Frediano Ziglio <fziglio@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v2:
- removed unused variable 'device' in psbfb_create

Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Reviewed-by: NPatrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v2:
- Remove unnecessary dealloc cmap in error handling path

Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

Cc: Rob Clark <robdclark@gmail.com>
Cc: Stephane Viau <sviau@codeaurora.org>
Cc: Hai Li <hali@codeaurora.org>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

v2:
- Fix up error handling path in tegra_fbdev_probe

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: "Terje Bergström" <tbergstrom@nvidia.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use the newly created wrapper drm_fb_helper functions instead of calling
core fbdev functions directly. They also simplify the fb_info creation.

Cleaned up the error handling in astfb_create a bit.

v2:
- removed unused variable 'device' in astfb_create

Cc: David Airlie <airlied@linux.ie>
Cc: "Y.C. Chen" <yc_chen@aspeedtech.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: NArchit Taneja <architt@codeaurora.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>