introduce lower_32_bits() macro
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.
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index fdbbf72..aaa998f 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -75,6 +75,12 @@
*/
#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) ((u32)(n))
+
#define KERN_EMERG "<0>" /* system is unusable */
#define KERN_ALERT "<1>" /* action must be taken immediately */
#define KERN_CRIT "<2>" /* critical conditions */