drm/tegra: falcon: Set DMACTX field on DMA transactions

The DMACTX field determines which context, as specified in the
TRANSCFG register, is used. While during boot it doesn't matter
which is used, later on it matters and this value is reused by
the firmware.

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

drm/tegra: falcon: Clarify address usage

Rename paddr -> iova and vaddr -> virt to make it clearer how these
addresses are used. This is important for a subsequent patch that makes
a distinction between the physical address (physical address of the
system memory from the CPU's point of view) and the IOVA (physical
address of the system memory from the device's point of view).

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

drm/tegra: Remove memory allocation from Falcon library

Having to provide allocator hooks to the Falcon library is somewhat
cumbersome and it doesn't give the users of the library a lot of
flexibility to deal with allocations. Instead, remove the notion of
Falcon "operations" and let drivers deal with the memory allocations
themselves.

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

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drm/tegra: Add falcon helper library

Add a set of falcon helper routines for use by the tegradrm client drivers
of the various falcon-based engines.

The falcon is a microcontroller that acts as a frontend for the rest of a
particular Tegra engine. In order to properly utilize these engines, the
frontend must be booted before pushing any commands.

Based on work by Andrew Chew <achew@nvidia.com>

Signed-off-by: Andrew Chew <achew@nvidia.com>
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>