[PATCH] introduce lower_32_bits() macro

[Joerg Roedel]

The file kernel.h contains the upper_32_bits macro. This patch adds the other
part, the lower_32_bits macro. Its first use will be in the driver for AMD
IOMMU.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
 include/linux/kernel.h |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index f9cd7a5..6fd2977 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -73,6 +73,12 @@ extern const char linux_proc_banner[];
  */
 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
 
+/**
+ * lower_32_bits - return bits 0-31 of a number
+ * @n: the number we're accessing
+ */
+#define lower_32_bits(n) ((n) & 0xffffffffULL)
+
 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
 #define	KERN_CRIT	"<2>"	/* critical conditions			*/
-- 
1.5.3.7


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