drm/tegra: Changes for v5.3-rc1

This contains a couple of small improvements and cleanups for the Tegra
DRM driver.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621150753.19550-1-thierry.reding@gmail.com

So there is no need to check for a value that can never happen.  No need
to check the return value all anyway, as any debugfs call can take the
result of this function as an option just fine.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Based on 1 normalized pattern(s):

  this software is licensed under the terms of the gnu general public
  license version 2 as published by the free software foundation and
  may be copied distributed and modified under those terms this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Logical devices created by the host1x bus infrastructure don't need to
be associated with a device tree node. Doing so will cause the driver
core to attempt to hook up IOMMU operations and fail because it is not
a real device.

However, for backwards-compatibility, we need to provide various OF_*
uevent variables that were previously provided by of_device_uevent() and
which are parsed by libdrm in userspace when querying the available
devices. Do this by implementing a uevent callback for the host1x bus.

Signed-off-by: Thierry Reding <treding@nvidia.com>

Recent versions of the DMA API debug code have started to warn about
violations of the maximum DMA segment size. This is because the segment
size defaults to 64 KiB, which can easily be exceeded in large buffer
allocations such as used in DRM/KMS for framebuffers.

Technically the Tegra SMMU and ARM SMMU don't have a maximum segment
size (they map individual pages irrespective of whether they are
contiguous or not), so the choice of 4 MiB is a bit arbitrary here. The
maximum segment size is a 32-bit unsigned integer, though, so we can't
set it to the correct maximum size, which would be the size of the
aperture.

Signed-off-by: Thierry Reding <treding@nvidia.com>

When deferring probe, avoid logging a confusing error message. While at
it, make the error message more informational.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If SMMU support is not available, fall back to programming the bypass
stream ID (0x7f).

Fixes: de5469c21ff9 ("gpu: host1x: Program the channel stream ID")
Suggested-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
[treding@nvidia.com: rebase this on top of a later build fix]
Signed-off-by: Thierry Reding <treding@nvidia.com>

In case the IOMMU API is not available compiling host1x fails with
the following error:

  In file included from drivers/gpu/host1x/hw/host1x06.c:27:
  drivers/gpu/host1x/hw/channel_hw.c: In function ‘host1x_channel_set_streamid’:
  drivers/gpu/host1x/hw/channel_hw.c:118:30: error: implicit declaration of function
    ‘dev_iommu_fwspec_get’; did you mean ‘iommu_fwspec_free’?  [-Werror=implicit-function-declaration]
  struct iommu_fwspec *spec = dev_iommu_fwspec_get(channel->dev->parent);
                              ^~~~~~~~~~~~~~~~~~~~
                              iommu_fwspec_free

Fixes: de5469c21ff9 ("gpu: host1x: Program the channel stream ID")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>