drm/gem: rename GEM CMA helpers to GEM DMA helpers

Rename "GEM CMA" helpers to "GEM DMA" helpers - considering the
hierarchy of APIs (mm/cma -> dma -> gem dma) calling them "GEM
DMA" seems to be more applicable.

Besides that, commit e57924d4ae80 ("drm/doc: Task to rename CMA helpers")
requests to rename the CMA helpers and implies that people seem to be
confused about the naming.

In order to do this renaming the following script was used:

```
#!/bin/bash

DIRS="drivers/gpu include/drm Documentation/gpu"

REGEX_SYM_UPPER="[0-9A-Z_\-]"
REGEX_SYM_LOWER="[0-9a-z_\-]"

REGEX_GREP_UPPER="(${REGEX_SYM_UPPER}*)(GEM)_CMA_(${REGEX_SYM_UPPER}*)"
REGEX_GREP_LOWER="(${REGEX_SYM_LOWER}*)(gem)_cma_(${REGEX_SYM_LOWER}*)"

REGEX_SED_UPPER="s/${REGEX_GREP_UPPER}/\1\2_DMA_\3/g"
REGEX_SED_LOWER="s/${REGEX_GREP_LOWER}/\1\2_dma_\3/g"

# Find all upper case 'CMA' symbols and replace them with 'DMA'.
for ff in $(grep -REHl "${REGEX_GREP_UPPER}" $DIRS)
do
sed -i -E "$REGEX_SED_UPPER" $ff
done

# Find all lower case 'cma' symbols and replace them with 'dma'.
for ff in $(grep -REHl "${REGEX_GREP_LOWER}" $DIRS)
do
sed -i -E "$REGEX_SED_LOWER" $ff
done

# Replace all occurrences of 'CMA' / 'cma' in comments and
# documentation files with 'DMA' / 'dma'.
for ff in $(grep -RiHl " cma " $DIRS)
do
sed -i -E "s/ cma / dma /g" $ff
sed -i -E "s/ CMA / DMA /g" $ff
done

# Rename all 'cma_obj's to 'dma_obj'.
for ff in $(grep -RiHl "cma_obj" $DIRS)
do
sed -i -E "s/cma_obj/dma_obj/g" $ff
done
```

Only a few more manual modifications were needed, e.g. reverting the
following modifications in some DRM Kconfig files

- select CMA if HAVE_DMA_CONTIGUOUS
+ select DMA if HAVE_DMA_CONTIGUOUS

as well as manually picking the occurrences of 'CMA'/'cma' in comments and
documentation which relate to "GEM CMA", but not "FB CMA".

Also drivers/gpu/drm/Makefile was fixed up manually after renaming
drm_gem_cma_helper.c to drm_gem_dma_helper.c.

This patch is compile-time tested building a x86_64 kernel with
`make allyesconfig && make drivers/gpu/drm`.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com> #drivers/gpu/drm/arm
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220802000405.949236-4-dakr@redhat.com

drm/vc4: Warn if some v3d code is run on BCM2711

The BCM2711 has a separate driver for the v3d, and thus we can't call
into any of the driver entrypoints that rely on the v3d being there.

Let's add a bunch of checks and complain loudly if that ever happen.

Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220610115149.964394-15-maxime@cerno.tech

drm/vc4: Fix memory leak during BO teardown

During BO teardown, an indirect list 'uniform_addr_offsets' wasn't being
freed leading to leaking many 128B allocations. Fix the memory leak by
releasing it at teardown time.

Cc: stable@vger.kernel.org
Fixes: 6d45c81d229d ("drm/vc4: Add support for branching in shader validation.")
Signed-off-by: Daniel J Blueman <daniel@quora.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20180402071035.25356-1-daniel@quora.org

drm/vc4: Demote user-accessible DRM_ERROR paths to DRM_DEBUG.

Userspace shouldn't be able to spam dmesg by passing bad arguments.
This has particularly become an issues since we started using a bad
argument to set_tiling to detect if set_tiling was supported.

Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: 83753117f1de ("drm/vc4: Add get/set tiling ioctls.")
Link: https://patchwork.freedesktop.org/patch/msgid/20170725162733.28007-1-eric@anholt.net
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

drm/vc4: Extend and edit documentation for output from the RST

I had written most of my comments as if I was describing the
individual code files the way I used to for doxygen, while for RST we
want to describe things in a more chapter/section way where there's no
obvious relation to .c files.

Additionally, several of the files had stub descriptions that I've
taken this opportunity to extend.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170227201144.10970-4-eric@anholt.net

drm/vc4: Add fragment shader threading support

FS threading brings performance improvements of 0-20% in glmark2.

The validation code checks for thread switch signals and ensures that
the registers of the other thread are not touched, and that our clamps
are not live across thread switches. It also checks that the
threading and branching instructions do not interfere.

(Original patch by Jonas, changes by anholt for style cleanup,
removing validation the kernel doesn't need to do, and adding the flag
for userspace).

v2: Minor style fixes from checkpatch.

Signed-off-by: Jonas Pfeil <pfeiljonas@gmx.de>
Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Fix termination of the initial scan for branch targets.

The loop is scanning until the original max_ip (size of the BO), but
we want to not examine any code after the PROG_END's delay slots.
There was a block trying to do that, except that we had some early
continue statements if the signal wasn't a PROG_END or a BRANCH.

The failure mode would be that a valid shader is rejected because some
undefined memory after the PROG_END slots is parsed as a branch and
the rest of its setup is illegal. I haven't seen this in the wild,
but valgrind was complaining when about this up in the userland
simulator mode.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Allow some more signals to be packed with uniform resets.

The intent was to make sure people don't sneak in a small immediate or
something to change the interpretation of the uniform update args, but
these signals are just fine.

Fixes a validation failure in the current X server on some Render
operation.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Fix a "the the" typo in a comment.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Add support for branching in shader validation.

We're already checking that branch instructions are between the start
of the shader and the proper PROG_END sequence. The other thing we
need to make branching safe is to verify that the shader doesn't read
past the end of the uniforms stream.

To do that, we require that at any basic block reading uniforms have
the following instructions:

load_imm temp, <next offset within uniform stream>
add unif_addr, temp, unif

The instructions are generated by userspace, and the kernel verifies
that the load_imm is of the expected offset, and that the add adds it
to a uniform. We track which uniform in the stream that is, and at
draw call time fix up the uniform stream to have the address of the
start of the shader's uniforms at that location.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Add a bitmap of branch targets during shader validation.

This isn't used yet, it's just a first step toward loop validation.
During the main parsing of instructions, we need to know when we hit a
new basic block so that we can reset validated state.

v2: Fix a stray semicolon after an if block. (caught by kbuild test).

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Move validation's current/max ip into the validation struct.

Reduces the argument count for some of the functions, and will be used
more with the upcoming looping support.

Signed-off-by: Eric Anholt <eric@anholt.net>

drm/vc4: Add an API for creating GPU shaders in GEM BOs.

Since we have no MMU, the kernel needs to validate that the submitted
shader code won't make any accesses to memory that the user doesn't
control, which involves banning some operations (general purpose DMA
writes), and tracking where we need to write out pointers for other
operations (texture sampling). Once it's validated, we return a GEM
BO containing the shader, which doesn't allow mapping for write or
exporting to other subsystems.

v2: Use __u32-style types.

Signed-off-by: Eric Anholt <eric@anholt.net>