diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2010-12-08 12:39:12 -0800 |
|---|---|---|
| committer | AK <andi@firstfloor.org> | 2011-02-06 11:03:40 -0800 |
| commit | 92bc7287b38e4eb45ff34b1cd1b543da9d1e71bd (patch) | |
| tree | 1611c0bffb69855896009ce47370026f064dd59a /include | |
| parent | 78dd4b02b5d68c4d64557152a35941150f90ff82 (diff) | |
xen: Provide a variant of __RING_SIZE() that is an integer constant expression
commit 667c78afaec0ac500908e191e8f236e9578d7b1f upstream.
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 <jbeulich@novell.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
| -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. |