From: Jens Axboe <axboe@suse.de>
Date: Wed, 9 Nov 2005 08:24:14 +0000 (+0100)
Subject: [PATCH] Add generic_ffz for use for archs without an optimized version
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=2fa6471f93a50697668b232e7605e7350cfde86d;p=disktools.git

[PATCH] Add generic_ffz for use for archs without an optimized version
---

diff --git a/arch-alpha.h b/arch-alpha.h
index b1b1e8a..09293bd 100644
--- a/arch-alpha.h
+++ b/arch-alpha.h
@@ -13,5 +13,6 @@
 #endif
 
 #define nop	do { } while (0)
+#define ffz(v)	generic_ffz((v))
 
 #endif
diff --git a/arch-s390.h b/arch-s390.h
index 956dccf..b7048ad 100644
--- a/arch-s390.h
+++ b/arch-s390.h
@@ -13,5 +13,6 @@
 #endif
 
 #define nop	asm volatile ("diag 0,0,68" : : : "memory")
+#define ffz(v)	generic_ffz((v))
 
 #endif
diff --git a/arch.h b/arch.h
index 44d09e9..4ea55bc 100644
--- a/arch.h
+++ b/arch.h
@@ -10,6 +10,17 @@ enum {
 	arch_alpha,
 };
 
+static inline unsigned long generic_ffz(unsigned long word)
+{
+	int i;
+
+	for (i = 0; i < sizeof(word) * 8; i++)
+		if ((word & (1UL << i)) == 0)
+			return i;
+
+	return -1;
+}
+
 #if defined(__i386__)
 #include "arch-x86.h"
 #elif defined(__x86_64__)