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authorDwight Engen <dwight.engen@oracle.com>2014-12-11 20:26:15 +0300
committerDavid S. Miller <davem@davemloft.net>2014-12-12 05:52:45 +0300
commitfe47c3c2623d6914655f507a317a6b881bc7c6a4 (patch)
treeb9e30d272af800b1de1f59c7ebe661bc9ac7eb67 /arch/sparc/include/asm/vio.h
parent31f4888f51afb038f7f8e7e4b3f0a80587c92c9b (diff)
downloadlinux-fe47c3c2623d6914655f507a317a6b881bc7c6a4.tar.xz
vio: create routines for inc,dec vio dring indexes
Both sunvdc and sunvnet implemented distinct functionality for incrementing and decrementing dring indexes. Create common functions for use by both from the sunvnet versions, which were chosen since they will still work correctly in case a non power of two ring size is used. Signed-off-by: Dwight Engen <dwight.engen@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/include/asm/vio.h')
-rw-r--r--arch/sparc/include/asm/vio.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/vio.h b/arch/sparc/include/asm/vio.h
index fb124feb363b..8174f6cdbbbb 100644
--- a/arch/sparc/include/asm/vio.h
+++ b/arch/sparc/include/asm/vio.h
@@ -300,6 +300,21 @@ static inline u32 vio_dring_avail(struct vio_dring_state *dr,
((dr->prod - dr->cons) & (ring_size - 1)) - 1);
}
+static inline u32 vio_dring_next(struct vio_dring_state *dr, u32 index)
+{
+ if (++index == dr->num_entries)
+ index = 0;
+ return index;
+}
+
+static inline u32 vio_dring_prev(struct vio_dring_state *dr, u32 index)
+{
+ if (index == 0)
+ return dr->num_entries - 1;
+ else
+ return index - 1;
+}
+
#define VIO_MAX_TYPE_LEN 32
#define VIO_MAX_COMPAT_LEN 64