+# LN_EXPORT_KMAP_TO_PAGE
+#
+# 3.10 Export kmap_to_page
+#
+AC_DEFUN([LN_EXPORT_KMAP_TO_PAGE], [
+LB_CHECK_EXPORT([kmap_to_page], [mm/highmem.c],
+ [AC_DEFINE(HAVE_KMAP_TO_PAGE, 1,
+ [kmap_to_page is exported by the kernel])])
+]) # LN_EXPORT_KMAP_TO_PAG
+
+#
+# LN_CONFIG_SOCK_ACCEPT
+#
+# 4.11 commit cdfbabfb2f0ce983fdaa42f20e5f7842178fc01e added a flag
+# to handle a possible lockdep condition kernel socket accept.
+#
+AC_DEFUN([LN_CONFIG_SOCK_ACCEPT], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if 'struct sock' accept function requires a bool argument],
+kern_sock_flag, [
+ #include <linux/net.h>
+],[
+ ((struct socket *)0)->ops->accept(NULL, NULL, O_NONBLOCK, false);
+],[
+ AC_DEFINE(HAVE_KERN_SOCK_ACCEPT_FLAG_ARG, 1,
+ ['struct sock' accept function requires bool argument])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LN_CONFIG_SOCK_ACCEPT
+
+#
+# LN_CONFIG_SOCK_GETNAME
+#
+# 4.17 commit 9b2c45d479d0fb8647c9e83359df69162b5fbe5f getname()
+# does not take the length *int argument and returns the length
+#
+AC_DEFUN([LN_CONFIG_SOCK_GETNAME], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if 'getname' has two args],
+kern_sock_getname_2args, [
+ #include <linux/net.h>
+],[
+ kernel_getsockname(NULL, NULL);
+],[
+ AC_DEFINE(HAVE_KERN_SOCK_GETNAME_2ARGS, 1,
+ ['getname' has two args])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LN_CONFIG_SOCK_GETNAME
+
+#
+# LN_IB_DEVICE_OPS_EXISTS
+#
+# kernel 5.0 commit 521ed0d92ab0db3edd17a5f4716b7f698f4fce61
+# RDMA/core: Introduce ib_device_ops
+# ... introduces the ib_device_ops structure that defines all the
+# InfiniBand device operations in one place ...
+#
+AC_DEFUN([LN_IB_DEVICE_OPS_EXISTS], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if struct ib_device_ops is defined],
+ib_device_ops_test, [
+ #include <rdma/ib_verbs.h>
+],[
+ int x = offsetof(struct ib_device_ops, unmap_fmr);
+ x = x;
+ (void)x;
+],[
+ AC_DEFINE(HAVE_IB_DEVICE_OPS, 1,
+ [if struct ib_device_ops is defined])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LN_IB_DEVICE_OPS_EXISTS
+
+#
+# LN_IB_SG_DMA_ADDRESS_EXISTS
+#
+# kernel 5.1 commit a163afc88556e099271a7b423295bc5176fcecce
+# IB/core: Remove ib_sg_dma_address() and ib_sg_dma_len()
+# ... when dma_ops existed (3.6) ib_sg_dma_address() was not trivial ...
+#
+AC_DEFUN([LN_IB_SG_DMA_ADDRESS_EXISTS], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if ib_sg_dma_address wrapper exists],
+ib_sg_dma_address_test, [
+ #include <rdma/ib_verbs.h>
+],[
+ u64 x = ib_sg_dma_address(NULL, NULL);
+ x = x;
+ (void)x;
+],[
+ AC_DEFINE(HAVE_IB_SG_DMA_ADDRESS, 1,
+ [if ib_sg_dma_address wrapper exists])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LN_IB_SG_DMA_ADDRESS_EXISTS
+
+#