Linux 4.12-rc7

Needed at least rc6 for drm-misc-next-fixes, may as well go to rc7

drm/tegra: Changes for v4.13-rc1

This starts off with the addition of more documentation for the host1x
and DRM drivers and finishes with a slew of fixes and enhancements for
the staging IOCTLs as a result of the awesome work done by Dmitry and
Erik on the grate reverse-engineering effort.

* tag 'drm/tegra/for-4.13-rc1' of git://anongit.freedesktop.org/tegra/linux:
  gpu: host1x: At first try a non-blocking allocation for the gather copy
  gpu: host1x: Refactor channel allocation code
  gpu: host1x: Remove unused host1x_cdma_stop() definition
  gpu: host1x: Remove unused 'struct host1x_cmdbuf'
  gpu: host1x: Check waits in the firewall
  gpu: host1x: Correct swapped arguments in the is_addr_reg() definition
  gpu: host1x: Forbid unrelated SETCLASS opcode in the firewall
  gpu: host1x: Forbid RESTART opcode in the firewall
  gpu: host1x: Forbid relocation address shifting in the firewall
  gpu: host1x: Do not leak BO's phys address to userspace
  gpu: host1x: Correct host1x_job_pin() error handling
  gpu: host1x: Initialize firewall class to the job's one
  drm/tegra: dc: Disable plane if it is invisible
  drm/tegra: dc: Apply clipping to the plane
  drm/tegra: dc: Avoid reset asserts on Tegra20
  drm/tegra: Check syncpoint ID in the 'submit' IOCTL
  drm/tegra: Correct copying of waitchecks and disable them in the 'submit' IOCTL
  drm/tegra: Check for malformed offsets and sizes in the 'submit' IOCTL
  drm/tegra: Add driver documentation
  gpu: host1x: Flesh out kerneldoc

The blocking gather copy allocation is a major performance downside of the
Host1x firewall, it may take hundreds milliseconds which is unacceptable
for the real-time graphics operations. Let's try a non-blocking allocation
first as a least invasive solution, it makes opentegra (Xorg driver)
performance indistinguishable with/without the firewall.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

This is largely a rewrite of the Host1x channel allocation code, bringing
several changes:

- The previous code could deadlock due to an interaction
  between the 'reflock' mutex and CDMA timeout handling.
  This gets rid of the mutex.
- Support for more than 32 channels, required for Tegra186
- General refactoring, including better encapsulation
  of channel ownership handling into channel.c

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

There is no host1x_cdma_stop() in the code, let's remove its definition
from the header file.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Erik Faye-Lund <kusmabite@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

The struct host1x_cmdbuf is unused, let's remove it.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Erik Faye-Lund <kusmabite@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Check waits in the firewall in a way it is done for relocations.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Several channels could be made to write the same unit concurrently via
the SETCLASS opcode, trusting userspace is a bad idea. It should be
possible to drop the per-client channel reservation and add a per-unit
locking by inserting MLOCK's to the command stream to re-allow the
SETCLASS opcode, but it will be much more work. Let's forbid the
unit-unrelated class changes for now.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Erik Faye-Lund <kusmabite@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

The RESTART opcode terminates the gather and restarts the CDMA fetching
from a specified word << 2 relative to the CDMA start address. That
shouldn't be allowed to be done by userspace.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Erik Faye-Lund <kusmabite@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Incorrectly shifted relocation address will cause a lower memory
corruption and likely a hang on a write or a read of an arbitrary data
in case of IOMMU absence. As of now, there is no known use for the
address shifting and adding a proper shifts / sizes validation is a much
more work. Let's forbid shifts in the firewall till a proper validation
is implemented.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Erik Faye-Lund <kusmabite@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>