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authorIngo Molnar <mingo@elte.hu>2011-01-07 14:14:15 +0100
committerIngo Molnar <mingo@elte.hu>2011-01-07 14:14:15 +0100
commit1c2a48cf65580a276552151eb8f78d78c55b828e (patch)
tree68ed0628a276b33cb5aa0ad4899c1afe0a33a69d /include/xen/interface/io/ring.h
parent0aa002fe602939370e9476e5ec32b562000a0425 (diff)
parentcb600d2f83c854ec3d6660063e4466431999489b (diff)
Merge branch 'linus' into x86/apic-cleanups
Conflicts: arch/x86/include/asm/io_apic.h Merge reason: Resolve the conflict, update to a more recent -rc base Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/xen/interface/io/ring.h')
-rw-r--r--include/xen/interface/io/ring.h11
1 files changed, 9 insertions, 2 deletions
diff --git a/include/xen/interface/io/ring.h b/include/xen/interface/io/ring.h
index e8cbf431c8ccf..75271b9a8f61b 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.