From: Paul Mackerras <paulus@samba.org>
Date: Wed, 12 Mar 2008 22:39:55 +0000 (+1100)
Subject: [POWERPC] Add __ucmpdi2 for 64-bit comparisons in 32-bit kernels
X-Git-Tag: v3.12-rc1~22410^2~10
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=95ff54f5176a36f65522e46c670a571728328b10;p=kernel%2Fkernel-generic.git

[POWERPC] Add __ucmpdi2 for 64-bit comparisons in 32-bit kernels

Some drivers (such as V4L2) have code that causes gcc to generate
calls to __ucmpdi2 when compiling for 32-bit powerpc, which results
in either a link-time error or a module that can't be loaded, as
we don't currently have a __ucmpdi2.  This adds one so these drivers
can be used.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---

diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 5c2e253..9d2c566 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -785,6 +785,21 @@ _GLOBAL(__lshrdi3)
 	or	r4,r4,r7	# LSW |= t2
 	blr
 
+/*
+ * 64-bit comparison: __ucmpdi2(u64 a, u64 b)
+ * Returns 0 if a < b, 1 if a == b, 2 if a > b.
+ */
+_GLOBAL(__ucmpdi2)
+	cmplw	r3,r5
+	li	r3,1
+	bne	1f
+	cmplw	r4,r6
+	beqlr
+1:	li	r3,0
+	bltlr
+	li	r3,2
+	blr
+
 _GLOBAL(abs)
 	srawi	r4,r3,31
 	xor	r3,r3,r4
diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c
index aa9ff35..3e52122 100644
--- a/arch/powerpc/kernel/ppc_ksyms.c
+++ b/arch/powerpc/kernel/ppc_ksyms.c
@@ -149,6 +149,8 @@ long long __lshrdi3(long long, int);
 EXPORT_SYMBOL(__ashrdi3);
 EXPORT_SYMBOL(__ashldi3);
 EXPORT_SYMBOL(__lshrdi3);
+int __ucmpdi2(unsigned long long, unsigned long long);
+EXPORT_SYMBOL(__ucmpdi2);
 #endif
 
 EXPORT_SYMBOL(memcpy);