[ovs-dev] [PATCH 2/3] datapath: Add compile time check for rxhash

[Pravin B Shelar]

Some distribution kernel has backported skb->rxhash (e.g. RHEL)
Following patch allows use precalculated rxhash.

Signed-off-by: Pravin B Shelar <pshelar at nicira.com>
Reviewed-by: Thomas Graf <tgraf at redhat.com>
Acked-by: Jesse Gross <jesse at nicira.com>
---
 acinclude.m4                                 |    1 +
 datapath/linux/compat/flow_dissector.c       |    2 +-
 datapath/linux/compat/include/linux/skbuff.h |    2 +-
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/acinclude.m4 b/acinclude.m4
index f987fa0..94f9b61 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -240,6 +240,7 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
   # quoting rules.
   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [[[^@]]proto_data_valid],
                   [OVS_DEFINE([HAVE_PROTO_DATA_VALID])])
+  OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [rxhash])
   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_dst(],
                   [OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], 
diff --git a/datapath/linux/compat/flow_dissector.c b/datapath/linux/compat/flow_dissector.c
index f176f9a..7a0d09b 100644
--- a/datapath/linux/compat/flow_dissector.c
+++ b/datapath/linux/compat/flow_dissector.c
@@ -226,7 +226,7 @@ u32 __skb_get_rxhash(struct sk_buff *skb)
 	if (!hash)
 		hash = 1;
 
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,34)
+#ifdef HAVE_RXHASH
 	skb->rxhash = hash;
 #endif
 	return hash;
diff --git a/datapath/linux/compat/include/linux/skbuff.h b/datapath/linux/compat/include/linux/skbuff.h
index 3af3ddc..4f22600 100644
--- a/datapath/linux/compat/include/linux/skbuff.h
+++ b/datapath/linux/compat/include/linux/skbuff.h
@@ -220,7 +220,7 @@ static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
 extern u32 __skb_get_rxhash(struct sk_buff *skb);
 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
 {
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,34)
+#ifdef HAVE_RXHASH
 	if (skb->rxhash)
 		return skb->rxhash;
 #endif
-- 
1.7.1