From 9e2793f6e4e2ca452457e459f013cc8e6b08a789 Mon Sep 17 00:00:00 2001 From: Dave Gordon Date: Thu, 14 Jul 2016 14:52:03 +0100 Subject: [PATCH] drm/i915: compile-time consistency check on __EXEC_OBJECT flags Two different sets of flag bits are stored in the 'flags' member of a 'struct drm_i915_gem_exec_object2', and they're defined in two different source files, increasing the risk of an accidental clash. Some flags in this field are supplied by the user; these are defined in i915_drm.h, and they start from the LSB and work up. Other flags are defined in i915_gem_execbuffer, for internal use within that file only; they start from the MSB and work down. So here we add a compile-time check that the two sets of flags do not overlap, which would cause all sorts of confusion. Signed-off-by: Dave Gordon Reviewed-by: Daniel Vetter Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1468504324-12690-1-git-send-email-david.s.gordon@intel.com --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 12 ++++++++---- include/uapi/drm/i915_drm.h | 11 ++++++----- 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 1978633e7549..1bb1f251eafc 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -34,10 +34,11 @@ #include #include -#define __EXEC_OBJECT_HAS_PIN (1<<31) -#define __EXEC_OBJECT_HAS_FENCE (1<<30) -#define __EXEC_OBJECT_NEEDS_MAP (1<<29) -#define __EXEC_OBJECT_NEEDS_BIAS (1<<28) +#define __EXEC_OBJECT_HAS_PIN (1<<31) +#define __EXEC_OBJECT_HAS_FENCE (1<<30) +#define __EXEC_OBJECT_NEEDS_MAP (1<<29) +#define __EXEC_OBJECT_NEEDS_BIAS (1<<28) +#define __EXEC_OBJECT_INTERNAL_FLAGS (0xf<<28) /* all of the above */ #define BATCH_OFFSET_BIAS (256*1024) @@ -1007,6 +1008,9 @@ validate_exec_list(struct drm_device *dev, unsigned invalid_flags; int i; + /* INTERNAL flags must not overlap with external ones */ + BUILD_BUG_ON(__EXEC_OBJECT_INTERNAL_FLAGS & ~__EXEC_OBJECT_UNKNOWN_FLAGS); + invalid_flags = __EXEC_OBJECT_UNKNOWN_FLAGS; if (USES_FULL_PPGTT(dev)) invalid_flags |= EXEC_OBJECT_NEEDS_GTT; diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index d7e81a3886fd..51b9360bb376 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -698,12 +698,13 @@ struct drm_i915_gem_exec_object2 { */ __u64 offset; -#define EXEC_OBJECT_NEEDS_FENCE (1<<0) -#define EXEC_OBJECT_NEEDS_GTT (1<<1) -#define EXEC_OBJECT_WRITE (1<<2) +#define EXEC_OBJECT_NEEDS_FENCE (1<<0) +#define EXEC_OBJECT_NEEDS_GTT (1<<1) +#define EXEC_OBJECT_WRITE (1<<2) #define EXEC_OBJECT_SUPPORTS_48B_ADDRESS (1<<3) -#define EXEC_OBJECT_PINNED (1<<4) -#define __EXEC_OBJECT_UNKNOWN_FLAGS -(EXEC_OBJECT_PINNED<<1) +#define EXEC_OBJECT_PINNED (1<<4) +/* All remaining bits are MBZ and RESERVED FOR FUTURE USE */ +#define __EXEC_OBJECT_UNKNOWN_FLAGS (-(EXEC_OBJECT_PINNED<<1)) __u64 flags; __u64 rsvd1;