Unfortunately the latest InfiniBand software is not included in Linux

distributions but must be installed separately via the OFED package. The patch
below makes it easier to compile SCST-SRPT with the OFED kernel headers by
disabling the backported <linux/scatterlist.h> macro's when compiling with
OFED kernel headers. OFED namely has its own set of backported macro's. OFED
kernel headers are detected via the preprocessor symbol
__BACKPORT_LINUX_SCATTERLIST_H_TO_2_6_23__, which is defined in the OFED
header file <linux/scatterlist.h> only. This patch does not have any effect
when compiling SCST on a system where OFED has not been installed.

Signed-off-by: Bart Van Assche <bart.vanassche@gmail.com>
git-svn-id: https://scst.svn.sourceforge.net/svnroot/scst/trunk@824 d57e44dd-8a1f-0410-8b47-8ef2f437770f

diff --git a/scst/include/scst.h b/scst/include/scst.h
index f6af5fe..16424e6 100644 (file)
--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -2657,6 +2657,17 @@ void scst_aen_done(struct scst_aen *aen);
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24)
 
+/*
+ * The macro's sg_page(), sg_virt(), sg_init_table(), sg_assign_page() and
+ * sg_set_page() have been introduced in the 2.6.24 kernel. The definitions
+ * below are backports of the 2.6.24 macro's for older kernels. There is one
+ * exception however: when compiling SCST on a system with a pre-2.6.24 kernel
+ * (e.g. RHEL 5.x) where the OFED kernel headers have been installed, do not
+ * define the backported macro's because OFED has already defined these.
+ */
+
+#ifndef __BACKPORT_LINUX_SCATTERLIST_H_TO_2_6_23__
+
 static inline struct page *sg_page(struct scatterlist *sg)
 {
        return sg->page;
@@ -2685,6 +2696,8 @@ static inline void sg_set_page(struct scatterlist *sg, struct page *page,
        sg->length = len;
 }
 
+#endif
+
 #endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 24) */
 
 static inline void sg_clear(struct scatterlist *sg)