From f6c01530fd987eb70e051580d831ac04ef920352 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Mon, 27 Feb 2017 12:11:43 -0800 Subject: 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 Acked-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170227201144.10970-4-eric@anholt.net --- drivers/gpu/drm/vc4/vc4_validate_shaders.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'drivers/gpu/drm/vc4/vc4_validate_shaders.c') diff --git a/drivers/gpu/drm/vc4/vc4_validate_shaders.c b/drivers/gpu/drm/vc4/vc4_validate_shaders.c index 5dba13dd1e9b..0b2df5c6efb4 100644 --- a/drivers/gpu/drm/vc4/vc4_validate_shaders.c +++ b/drivers/gpu/drm/vc4/vc4_validate_shaders.c @@ -24,16 +24,21 @@ /** * DOC: Shader validator for VC4. * - * The VC4 has no IOMMU between it and system memory, so a user with - * access to execute shaders could escalate privilege by overwriting - * system memory (using the VPM write address register in the - * general-purpose DMA mode) or reading system memory it shouldn't - * (reading it as a texture, or uniform data, or vertex data). + * Since the VC4 has no IOMMU between it and system memory, a user + * with access to execute shaders could escalate privilege by + * overwriting system memory (using the VPM write address register in + * the general-purpose DMA mode) or reading system memory it shouldn't + * (reading it as a texture, uniform data, or direct-addressed TMU + * lookup). * - * This walks over a shader BO, ensuring that its accesses are - * appropriately bounded, and recording how many texture accesses are - * made and where so that we can do relocations for them in the + * The shader validator walks over a shader's BO, ensuring that its + * accesses are appropriately bounded, and recording where texture + * accesses are made so that we can do relocations for them in the * uniform stream. + * + * Shader BO are immutable for their lifetimes (enforced by not + * allowing mmaps, GEM prime export, or rendering to from a CL), so + * this validation is only performed at BO creation time. */ #include "vc4_drv.h" -- cgit v1.2.3