--- drivers/block/nvme.c	2011-05-12 13:52:17.000000000 -0400
+++ drivers/block/nvme.c	2011-05-12 01:24:57.000000000 -0400
@@ -41,6 +41,65 @@
 #include <linux/types.h>
 #include <linux/version.h>
 
+/* In v2.6.35, the REQ and BIO_RW flags were unified.  The FUA flag
+ * doesn't have the same meaning as barrier, so don't ship this code
+ * into production on earlier kernels.
+ */
+#ifndef REQ_RAHEAD
+#define REQ_RAHEAD	(1 << BIO_RW_AHEAD)
+#define REQ_FLUSH	(1 << BIO_RW_BARRIER)
+#undef REQ_FUA
+#define REQ_FUA		(1 << BIO_RW_BARRIER)
+#warning FUA is broken
+#endif
+
+#ifndef RHEL_RELEASE_CODE
+#define RHEL_RELEASE_CODE 0
+#define RHEL_RELEASE_VERSION(x, y)	1
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,35)
+
+#if RHEL_RELEASE_CODE < RHEL_RELEASE_VERSION(6,0)
+#define AFFINITY_HINT
+#endif
+
+#endif
+
+#ifdef AFFINITY_HINT
+/* Since 2.6.35, we've exposed irq_set_affinity_hint to modules.  Bodge
+ * it for earlier kernels by looking up the address of irq_set_affinity
+ * in kallsyms and passing it as a module parameter */
+static unsigned long irq_set_affinity_sym;
+module_param(irq_set_affinity_sym, ulong, 0);
+
+static int irq_set_affinity_hint(unsigned int irq, const struct cpumask *mask)
+{
+	int (*set_affinity)(unsigned int, const struct cpumask *);
+	if (!irq_set_affinity_sym)
+		return 0;
+	if (!mask)
+		return 0;
+	set_affinity = (void *)irq_set_affinity_sym;
+	return set_affinity(irq, mask);
+}
+#endif
+
+/* 2.6.34 introduced this offset */
+#ifndef POISON_POINTER_DELTA
+#define POISON_POINTER_DELTA	0
+#endif
+
+/* 2.6.34 renamed this function */
+#ifndef for_each_set_bit
+#define for_each_set_bit for_each_bit
+#endif
+
+/* A lie anyway; I haven't added support for the DSM command yet */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,33) && RHEL_RELEASE_CODE < RHEL_RELEASE_VERSION(6,0)
+#define QUEUE_FLAG_DISCARD	0
+#endif
+
 #define NVME_Q_DEPTH 1024
 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
 #define CQ_SIZE(depth)		(depth * sizeof(struct nvme_completion))