From 667c78afaec0ac500908e191e8f236e9578d7b1f Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Wed, 8 Dec 2010 12:39:12 -0800 Subject: xen: Provide a variant of __RING_SIZE() that is an integer constant expression Without this, gcc 4.5 won't compile xen-netfront and xen-blkfront, where this is being used to specify array sizes. Signed-off-by: Jan Beulich Signed-off-by: Jeremy Fitzhardinge Cc: Jens Axboe Cc: David Miller Cc: Stable Kernel Signed-off-by: Linus Torvalds --- include/xen/interface/io/ring.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'include/xen/interface') 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. -- cgit v1.2.3