kernel/drivers/gpu/drm/vc4/vc4_validate.c, branch linux-4.17.y

drm/vc4_validate: Remove VLA usage

2018-03-16T22:51:52Z

In preparation to enabling -Wvla, remove VLA. In this particular case use macro ARRAY_SIZE so the length of array _bo_ can be computed at preprocessing time. The use of stack Variable Length Arrays needs to be avoided, as they can be a vector for stack exhaustion, which can be both a runtime bug or a security flaw. Also, in general, as code evolves it is easy to lose track of how big a VLA can get. Thus, we can end up having runtime failures that are hard to debug. Also, fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Gustavo A. R. Silva Signed-off-by: Eric Anholt Reviewed-by: Eric Anholt Link: https://patchwork.freedesktop.org/patch/msgid/20180313143151.GA27486@embeddedgus

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

2017-08-08T20:20:11Z

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 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

drm/vc4: fix spelling mistake: "dimesions" -> "dimensions"

2017-05-16T16:42:20Z

Trivial fix to spelling mistake in DRM_ERROR message and split over two lines to clean up a "line over 80 characters" checkpatch warning. Signed-off-by: Colin Ian King Reviewed-by: Eric Anholt Link: http://patchwork.freedesktop.org/patch/msgid/20170514170016.6802-1-colin.king@canonical.com

drm/vc4: Allow using more than 256MB of CMA memory.

2017-04-18T21:32:20Z

Until now, we've had to limit Raspberry Pi to 256MB of CMA memory to keep from triggering the hardware addressing bug between the tile binner and the tile alloc memory (where the top 4 bits come from the tile state data array's address). To work around that and allow more memory to be reserved for graphics, allocate a single BO to store tile state data arrays and tile alloc/overflow memory while the GPU is active, and make sure that that one BO doesn't happen to cross a 256MB boundary. With that in place, we can allocate textures and shaders anywhere in system memory (still contiguous, of course). Signed-off-by: Eric Anholt Link: http://patchwork.freedesktop.org/patch/msgid/20170327231025.19391-1-eric@anholt.net Reviewed-by: Boris Brezillon

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

2017-02-28T20:51:49Z

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 Acked-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170227201144.10970-4-eric@anholt.net

drm/vc4: Convert existing documentation to actual kerneldoc.

2017-02-28T20:51:48Z

I'm going to hook vc4 up to the sphinx build, so clean up its comments to not generate warnings when we do. Signed-off-by: Eric Anholt Acked-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170227201144.10970-2-eric@anholt.net

drm/vc4: Add fragment shader threading support

2016-11-16T21:25:26Z

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 Signed-off-by: Eric Anholt

drm/vc4: Add support for rendering with ETC1 textures.

2016-11-04T01:55:46Z

The validation for it ends up being quite simple, but I hadn't got around to it before merging the driver. For backwards compatibility, we also need to add a flag so that the userspace GL driver can easily tell if the kernel will allow ETC1 textures (on an old kernel, it will continue to convert to RGBA8) Signed-off-by: Eric Anholt

drm/vc4: Fix races when the CS reads from render targets.

2016-10-06T18:53:50Z

With the introduction of bin/render pipelining, the previous job may not be completed when we start binning the next one. If the previous job wrote our VBO, IB, or CS textures, then the binning stage might get stale or uninitialized results. Fixes the major rendering failure in glmark2 -b terrain. Signed-off-by: Eric Anholt Fixes: ca26d28bbaa3 ("drm/vc4: improve throughput by pipelining binning and rendering jobs") Cc: stable@vger.kernel.org

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

2016-07-15T22:19:50Z

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, 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