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| author | Ingo Molnar <mingo@elte.hu> | 2010-12-23 09:48:41 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-12-23 09:48:41 +0100 |
| commit | 26e20a108caca6231c6a5ec659f815a866904751 (patch) | |
| tree | 36932c208a9e8994bfd7ed4eaf48b9c33f71fbe3 /include/xen/interface/io/ring.h | |
| parent | 691513f70d3957939a318da970987b876c720861 (diff) | |
| parent | 90a8a73c06cc32b609a880d48449d7083327e11a (diff) | |
Merge commit 'v2.6.37-rc7' into x86/security
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. |