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| author | Paul Mundt <lethal@linux-sh.org> | 2010-12-22 06:56:10 +0300 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2010-12-22 06:56:10 +0300 |
| commit | 7ccbefe07ea0a3570e44d1ec13a307552ee4dadd (patch) | |
| tree | ba0299694a9f3940f289b6a29cadab853906e3d2 /include/xen/interface/io/ring.h | |
| parent | 623eb15647fc35c5a8cd38985d5958240eb072c1 (diff) | |
| parent | 90a8a73c06cc32b609a880d48449d7083327e11a (diff) | |
| download | linux-7ccbefe07ea0a3570e44d1ec13a307552ee4dadd.tar.xz | |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'include/xen/interface/io/ring.h')
| -rw-r--r-- | include/xen/interface/io/ring.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/include/xen/interface/io/ring.h b/include/xen/interface/io/ring.h index e8cbf431c8cc..75271b9a8f61 100644 --- a/include/xen/interface/io/ring.h +++ b/include/xen/interface/io/ring.h @@ -24,8 +24,15 @@ typedef unsigned int RING_IDX; * A ring contains as many entries as will fit, rounded down to the nearest * power of two (so we can mask with (size-1) to loop around). */ -#define __RING_SIZE(_s, _sz) \ - (__RD32(((_sz) - (long)&(_s)->ring + (long)(_s)) / sizeof((_s)->ring[0]))) +#define __CONST_RING_SIZE(_s, _sz) \ + (__RD32(((_sz) - offsetof(struct _s##_sring, ring)) / \ + sizeof(((struct _s##_sring *)0)->ring[0]))) + +/* + * The same for passing in an actual pointer instead of a name tag. + */ +#define __RING_SIZE(_s, _sz) \ + (__RD32(((_sz) - (long)&(_s)->ring + (long)(_s)) / sizeof((_s)->ring[0]))) /* * Macros to make the correct C datatypes for a new kind of ring. |