[PATCH] powerpc: Add gcc 128-bit shift helpers

[Herbert Xu <herbert@gondor.apana.org.au>]

On Thu, May 15, 2025 at 08:06:09PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   484803582c77061b470ac64a634f25f89715be3f
> commit: c66d7ebbe2fa14e41913adb421090a7426f59786 [10914/11408] crypto: powerpc/poly1305 - Add SIMD fallback
> config: powerpc64-randconfig-002-20250515 (https://download.01.org/0day-ci/archive/20250515/202505152053.FrKekjCe-lkp@intel.com/config)
> compiler: powerpc64-linux-gcc (GCC) 8.5.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250515/202505152053.FrKekjCe-lkp@intel.com/reproduce)

Thanks for the report.  This patch should fix the problem.

---8<---
When optimising for size, gcc generates out-of-line calls for 128-bit
integer shifts.  Add these functions to avoid build errors.

Fixes: c66d7ebbe2fa ("crypto: powerpc/poly1305 - Add SIMD fallback")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505152053.FrKekjCe-lkp@intel.com/
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 1cd74673cbf7..a41c071c1652 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -87,3 +87,5 @@ obj-$(CONFIG_CRC_T10DIF_ARCH) += crc-t10dif-powerpc.o
 crc-t10dif-powerpc-y := crc-t10dif-glue.o crct10dif-vpmsum_asm.o
 
 obj-$(CONFIG_PPC64) += $(obj64-y)
+
+obj-$(CONFIG_ARCH_SUPPORTS_INT128) += tishift.o
diff --git a/arch/powerpc/lib/tishift.S b/arch/powerpc/lib/tishift.S
new file mode 100644
index 000000000000..79afef2d8d54
--- /dev/null
+++ b/arch/powerpc/lib/tishift.S
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2025 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+#include <asm/ppc_asm.h>
+#include <linux/export.h>
+
+_GLOBAL(__lshrti3)
+	cmplwi	r5,63
+	ble	1f
+	addi	r5,r5,-64
+	srd	r3,r4,r5
+	li	r4,0
+	blr
+1:
+	subfic	r7,r5,64
+	srd	r3,r3,r5
+	sld	r6,r4,r7
+	srd	r4,r4,r5
+	or	r3,r3,r6
+	blr
+EXPORT_SYMBOL(__lshrti3)
+
+_GLOBAL(__ashrti3)
+	cmplwi	r5,63
+	ble	1f
+	addi	r5,r5,-64
+	srad	r3,r4,r5
+	sradi	r4,r4,63
+	blr
+1:
+	subfic	r7,r5,64
+	srd	r3,r3,r5
+	sld	r6,r4,r7
+	srad	r4,r4,r5
+	or	r3,r3,r6
+	blr
+EXPORT_SYMBOL(__ashrti3)
+
+_GLOBAL(__ashlti3)
+	cmplwi	r5,63
+	ble	1f
+	addi	r5,r5,-64
+	sld	r4,r3,r5
+	li	r3,0
+	blr
+1:
+	subfic	r7,r5,64
+	sld	r4,r4,r5
+	srd	r6,r3,r7
+	sld	r3,r3,r5
+	or	r4,r4,r6
+	blr
+EXPORT_SYMBOL(__ashlti3)
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt