diff options
Diffstat (limited to 'xen/public/io/ring.h')
| -rw-r--r-- | xen/public/io/ring.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/xen/public/io/ring.h b/xen/public/io/ring.h index 6ce1d0d4..8669564b 100644 --- a/xen/public/io/ring.h +++ b/xen/public/io/ring.h @@ -50,6 +50,12 @@ 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 __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]))) |