From patchwork series 435721

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=435721

arch/powerpc/include/asm/time.h

@@ -86,7 +86,7 @@ static inline unsigned long tb_ticks_since(unsigned long tstamp)
 #define mulhdu(x,y) \
 ({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
 #else
-extern u64 mulhdu(u64, u64);
+#define mulhdu(x, y)	mul_u64_u64_shr(x, y, 64)
 #endif
 
 extern void div128_by_32(u64 dividend_high, u64 dividend_low,

arch/powerpc/kernel/misc_32.S

@@ -27,32 +27,6 @@
 
 	.text
 
-/*
- * This returns the high 64 bits of the product of two 64-bit numbers.
- */
-_GLOBAL(mulhdu)
-	cmpwi	r6,0
-	cmpwi	cr1,r3,0
-	mr	r10,r4
-	mulhwu	r4,r4,r5
-	beq	1f
-	mulhwu	r0,r10,r6
-	mullw	r7,r10,r5
-	addc	r7,r0,r7
-	addze	r4,r4
-1:	beqlr	cr1		/* all done if high part of A is 0 */
-	mullw	r9,r3,r5
-	mulhwu	r10,r3,r5
-	beq	2f
-	mullw	r0,r3,r6
-	mulhwu	r8,r3,r6
-	addc	r7,r0,r7
-	adde	r4,r4,r8
-	addze	r10,r10
-2:	addc	r4,r4,r9
-	addze	r3,r10
-	blr
-
 /*
  * reloc_got2 runs through the .got2 section adding an offset
  * to each entry.