From: Joerg Roedel <joerg.roedel@amd.com>
Date: Wed, 30 Jul 2008 05:33:42 +0000 (-0700)
Subject: introduce lower_32_bits() macro
X-Git-Tag: firefly_0821_release~18562
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=204b885e7322656284626949e51f292fe61313fa;p=firefly-linux-kernel-4.4.55.git

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 fdbbf72ca2eb..aaa998f65c7a 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -75,6 +75,12 @@ 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) ((u32)(n))
+
 #define	KERN_EMERG	"<0>"	/* system is unusable			*/
 #define	KERN_ALERT	"<1>"	/* action must be taken immediately	*/
 #define	KERN_CRIT	"<2>"	/* critical conditions			*/