xtensa gcc-13 has changed multiplication handling and may now use
__umulsidi3 helper where it used to use __muldi3. As a result building
the kernel with the new gcc may fail with the following error:
linux/init/main.c:1287: undefined reference to `__umulsidi3'
Fix the build by providing __umulsidi3 implementation for xtensa.
Cc: stable@xxxxxxxxxxxxxxx # 5.18+
Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
---
arch/xtensa/kernel/xtensa_ksyms.c | 2 +
arch/xtensa/lib/Makefile | 2 +-
arch/xtensa/lib/umulsidi3.S | 230 ++++++++++++++++++++++++++++++
3 files changed, 233 insertions(+), 1 deletion(-)
create mode 100644 arch/xtensa/lib/umulsidi3.S
diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c
index b0bc8897c924..2a31b1ab0c9f 100644
--- a/arch/xtensa/kernel/xtensa_ksyms.c
+++ b/arch/xtensa/kernel/xtensa_ksyms.c
@@ -62,6 +62,7 @@ extern int __modsi3(int, int);
extern int __mulsi3(int, int);
extern unsigned int __udivsi3(unsigned int, unsigned int);
extern unsigned int __umodsi3(unsigned int, unsigned int);
+extern unsigned long long __umulsidi3(unsigned int, unsigned int);
EXPORT_SYMBOL(__ashldi3);
EXPORT_SYMBOL(__ashrdi3);
@@ -71,6 +72,7 @@ EXPORT_SYMBOL(__modsi3);
EXPORT_SYMBOL(__mulsi3);
EXPORT_SYMBOL(__udivsi3);
EXPORT_SYMBOL(__umodsi3);
+EXPORT_SYMBOL(__umulsidi3);
unsigned int __sync_fetch_and_and_4(volatile void *p, unsigned int v)
{
diff --git a/arch/xtensa/lib/Makefile b/arch/xtensa/lib/Makefile
index d4e9c397e3fd..7ecef0519a27 100644
--- a/arch/xtensa/lib/Makefile
+++ b/arch/xtensa/lib/Makefile
@@ -5,7 +5,7 @@
lib-y += memcopy.o memset.o checksum.o \
ashldi3.o ashrdi3.o lshrdi3.o \
- divsi3.o udivsi3.o modsi3.o umodsi3.o mulsi3.o \
+ divsi3.o udivsi3.o modsi3.o umodsi3.o mulsi3.o umulsidi3.o \
usercopy.o strncpy_user.o strnlen_user.o
lib-$(CONFIG_PCI) += pci-auto.o
lib-$(CONFIG_KCSAN) += kcsan-stubs.o
diff --git a/arch/xtensa/lib/umulsidi3.S b/arch/xtensa/lib/umulsidi3.S
new file mode 100644
index 000000000000..136081647942
--- /dev/null
+++ b/arch/xtensa/lib/umulsidi3.S
@@ -0,0 +1,230 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later WITH GCC-exception-2.0 */
+#include <linux/linkage.h>
+#include <asm/asmmacro.h>
+#include <asm/core.h>
+
+#if !XCHAL_HAVE_MUL16 && !XCHAL_HAVE_MUL32 && !XCHAL_HAVE_MAC16
+#define XCHAL_NO_MUL 1
+#endif
+
+ENTRY(__umulsidi3)
+
+#ifdef __XTENSA_CALL0_ABI__
+ abi_entry(32)
+ s32i a12, sp, 16
+ s32i a13, sp, 20
+ s32i a14, sp, 24
+ s32i a15, sp, 28
+#elif XCHAL_NO_MUL
+ /* This is not really a leaf function; allocate enough stack space
+ to allow CALL12s to a helper function. */
+ abi_entry(32)
+#else
+ abi_entry_default
+#endif
+
+#ifdef __XTENSA_EB__
+#define wh a2
+#define wl a3
+#else
+#define wh a3
+#define wl a2
+#endif /* __XTENSA_EB__ */
+
+ /* This code is taken from the mulsf3 routine in ieee754-sf.S.
+ See more comments there. */
+
+#if XCHAL_HAVE_MUL32_HIGH
+ mull a6, a2, a3
+ muluh wh, a2, a3
+ mov wl, a6
+
+#else /* ! MUL32_HIGH */
+
+#if defined(__XTENSA_CALL0_ABI__) && XCHAL_NO_MUL
+ /* a0 and a8 will be clobbered by calling the multiply function
+ but a8 is not used here and need not be saved. */
+ s32i a0, sp, 0
+#endif
+
+#if XCHAL_HAVE_MUL16 || XCHAL_HAVE_MUL32
+
+#define a2h a4
+#define a3h a5
+
+ /* Get the high halves of the inputs into registers. */
+ srli a2h, a2, 16
+ srli a3h, a3, 16
+
+#define a2l a2
+#define a3l a3
+
+#if XCHAL_HAVE_MUL32 && !XCHAL_HAVE_MUL16
+ /* Clear the high halves of the inputs. This does not matter
+ for MUL16 because the high bits are ignored. */
+ extui a2, a2, 0, 16
+ extui a3, a3, 0, 16
+#endif
+#endif /* MUL16 || MUL32 */
+
+
+#if XCHAL_HAVE_MUL16
+
+#define do_mul(dst, xreg, xhalf, yreg, yhalf) \
+ mul16u dst, xreg ## xhalf, yreg ## yhalf
+
+#elif XCHAL_HAVE_MUL32
+
+#define do_mul(dst, xreg, xhalf, yreg, yhalf) \
+ mull dst, xreg ## xhalf, yreg ## yhalf
+
+#elif XCHAL_HAVE_MAC16
+
+/* The preprocessor insists on inserting a space when concatenating after
+ a period in the definition of do_mul below. These macros are a workaround
+ using underscores instead of periods when doing the concatenation. */
+#define umul_aa_ll umul.aa.ll
+#define umul_aa_lh umul.aa.lh
+#define umul_aa_hl umul.aa.hl
+#define umul_aa_hh umul.aa.hh
+
+#define do_mul(dst, xreg, xhalf, yreg, yhalf) \
+ umul_aa_ ## xhalf ## yhalf xreg, yreg; \
+ rsr dst, ACCLO
+
+#else /* no multiply hardware */
+
+#define set_arg_l(dst, src) \
+ extui dst, src, 0, 16
+#define set_arg_h(dst, src) \
+ srli dst, src, 16
+
+#ifdef __XTENSA_CALL0_ABI__
+#define do_mul(dst, xreg, xhalf, yreg, yhalf) \
+ set_arg_ ## xhalf (a13, xreg); \
+ set_arg_ ## yhalf (a14, yreg); \
+ call0 .Lmul_mulsi3; \
+ mov dst, a12
+#else
+#define do_mul(dst, xreg, xhalf, yreg, yhalf) \
+ set_arg_ ## xhalf (a14, xreg); \
+ set_arg_ ## yhalf (a15, yreg); \
+ call12 .Lmul_mulsi3; \
+ mov dst, a14
+#endif /* __XTENSA_CALL0_ABI__ */
+
+#endif /* no multiply hardware */
+
+ /* Add pp1 and pp2 into a6 with carry-out in a9. */
+ do_mul(a6, a2, l, a3, h) /* pp 1 */
+ do_mul(a11, a2, h, a3, l) /* pp 2 */
+ movi a9, 0
+ add a6, a6, a11
+ bgeu a6, a11, 1f
+ addi a9, a9, 1
+1:
+ /* Shift the high half of a9/a6 into position in a9. Note that
+ this value can be safely incremented without any carry-outs. */
+ ssai 16
+ src a9, a9, a6
+
+ /* Compute the low word into a6. */
+ do_mul(a11, a2, l, a3, l) /* pp 0 */
+ sll a6, a6
+ add a6, a6, a11
+ bgeu a6, a11, 1f
+ addi a9, a9, 1
+1:
+ /* Compute the high word into wh. */
+ do_mul(wh, a2, h, a3, h) /* pp 3 */
+ add wh, wh, a9
+ mov wl, a6
+
+#endif /* !MUL32_HIGH */
+
+#if defined(__XTENSA_CALL0_ABI__) && XCHAL_NO_MUL
+ /* Restore the original return address. */
+ l32i a0, sp, 0
+#endif
+#ifdef __XTENSA_CALL0_ABI__
+ l32i a12, sp, 16
+ l32i a13, sp, 20
+ l32i a14, sp, 24
+ l32i a15, sp, 28
+ abi_ret(32)
+#else
+ abi_ret_default
+#endif
+
+#if XCHAL_NO_MUL
+
+ .macro do_addx2 dst, as, at, tmp
+#if XCHAL_HAVE_ADDX
+ addx2 \dst, \as, \at
+#else
+ slli \tmp, \as, 1
+ add \dst, \tmp, \at
+#endif
+ .endm
+
+ .macro do_addx4 dst, as, at, tmp
+#if XCHAL_HAVE_ADDX
+ addx4 \dst, \as, \at
+#else
+ slli \tmp, \as, 2
+ add \dst, \tmp, \at
+#endif
+ .endm
+
+ .macro do_addx8 dst, as, at, tmp
+#if XCHAL_HAVE_ADDX
+ addx8 \dst, \as, \at
+#else
+ slli \tmp, \as, 3
+ add \dst, \tmp, \at
+#endif
+ .endm
+
+ /* For Xtensa processors with no multiply hardware, this simplified
+ version of _mulsi3 is used for multiplying 16-bit chunks of
+ the floating-point mantissas. When using CALL0, this function
+ uses a custom ABI: the inputs are passed in a13 and a14, the
+ result is returned in a12, and a8 and a15 are clobbered. */
+ .align 4
+.Lmul_mulsi3:
+ abi_entry_default
+
+ .macro mul_mulsi3_body dst, src1, src2, tmp1, tmp2
+ movi \dst, 0
+1: add \tmp1, \src2, \dst
+ extui \tmp2, \src1, 0, 1
+ movnez \dst, \tmp1, \tmp2
+
+ do_addx2 \tmp1, \src2, \dst, \tmp1
+ extui \tmp2, \src1, 1, 1
+ movnez \dst, \tmp1, \tmp2
+
+ do_addx4 \tmp1, \src2, \dst, \tmp1
+ extui \tmp2, \src1, 2, 1
+ movnez \dst, \tmp1, \tmp2
+
+ do_addx8 \tmp1, \src2, \dst, \tmp1
+ extui \tmp2, \src1, 3, 1
+ movnez \dst, \tmp1, \tmp2
+
+ srli \src1, \src1, 4
+ slli \src2, \src2, 4
+ bnez \src1, 1b
+ .endm
+
+#ifdef __XTENSA_CALL0_ABI__
+ mul_mulsi3_body a12, a13, a14, a15, a8
+#else
+ /* The result will be written into a2, so save that argument in a4. */
+ mov a4, a2
+ mul_mulsi3_body a2, a4, a3, a5, a6
+#endif
+ abi_ret_default
+#endif /* XCHAL_NO_MUL */
+
+ENDPROC(__umulsidi3)
--
2.30.2
