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drm/i915: compile-time consistency check on __EXEC_OBJECT flags

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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 <david.s.gordon@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1468504324-12690-1-git-send-email-david.s.gordon@intel.com
This commit is contained in:
Dave Gordon 2016-07-14 14:52:03 +01:00 committed by Daniel Vetter
parent a87848750e
commit 9e2793f6e4
2 changed files with 14 additions and 9 deletions
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12
drivers/gpu/drm/i915/i915_gem_execbuffer.c
View file

@ -34,10 +34,11 @@
#include <linux/dma_remapping.h>
#include <linux/uaccess.h>
#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;

11
include/uapi/drm/i915_drm.h
View file

@ -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;