[PATCH] parisc: Fix xmpyu usage in 32-bit kernel

[Helge Deller <deller@xxxxxx>]

Dave noticed that the libgcc.a which is linked into the kernel binary
uses the xmpyu assembler statement. This asm statement uses floating
point registers which are forbidden in the kernel, because we don't save
the FP regs at kernel entry.

Switch the parisc kernel to use the already existing shared copies of
some GCC library routines instead of linking in those from libgcc.

This patch avoids all uses of xmpyu in the 32-bit kernel, but the 64-bit
kernel still needs fixing.

Reported-by: John David Anglin <dave.anglin@xxxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index fc17285f4da1..e412d5c6c64f 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -36,6 +36,12 @@ config PARISC
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_CPU_DEVICES
 	select GENERIC_LIB_DEVMEM_IS_ALLOWED
+	select GENERIC_LIB_ASHLDI3
+	select GENERIC_LIB_ASHRDI3
+	select GENERIC_LIB_LSHRDI3
+	select GENERIC_LIB_MULDI3
+	select GENERIC_LIB_CMPDI2
+	select GENERIC_LIB_UCMPDI2
 	select SYSCTL_ARCH_UNALIGN_ALLOW
 	select SYSCTL_EXCEPTION_TRACE
 	select HAVE_MOD_ARCH_SPECIFIC
diff --git a/arch/parisc/kernel/parisc_ksyms.c b/arch/parisc/kernel/parisc_ksyms.c
index 00297e8e1c88..da8c99c5a8c6 100644
--- a/arch/parisc/kernel/parisc_ksyms.c
+++ b/arch/parisc/kernel/parisc_ksyms.c
@@ -92,18 +92,6 @@ EXPORT_SYMBOL($$divI_12);
 EXPORT_SYMBOL($$divI_14);
 EXPORT_SYMBOL($$divI_15);

-extern void __ashrdi3(void);
-extern void __ashldi3(void);
-extern void __lshrdi3(void);
-extern void __muldi3(void);
-extern void __ucmpdi2(void);
-
-EXPORT_SYMBOL(__ashrdi3);
-EXPORT_SYMBOL(__ashldi3);
-EXPORT_SYMBOL(__lshrdi3);
-EXPORT_SYMBOL(__muldi3);
-EXPORT_SYMBOL(__ucmpdi2);
-
 asmlinkage void * __canonicalize_funcptr_for_compare(void *);
 EXPORT_SYMBOL(__canonicalize_funcptr_for_compare);

diff --git a/arch/parisc/lib/Makefile b/arch/parisc/lib/Makefile
index 7b197667faf6..2bfafb3c9ae0 100644
--- a/arch/parisc/lib/Makefile
+++ b/arch/parisc/lib/Makefile
@@ -4,6 +4,6 @@
 #

 lib-y	:= lusercopy.o bitops.o checksum.o io.o memset.o memcpy.o \
-	   ucmpdi2.o delay.o
+	   delay.o

 obj-y	:= iomap.o
diff --git a/arch/parisc/lib/ucmpdi2.c b/arch/parisc/lib/ucmpdi2.c
deleted file mode 100644
index 8e6014a142ef..000000000000
--- a/arch/parisc/lib/ucmpdi2.c
+++ /dev/null
@@ -1,26 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <linux/module.h>
-
-union ull_union {
-	unsigned long long ull;
-	struct {
-		unsigned int high;
-		unsigned int low;
-	} ui;
-};
-
-int __ucmpdi2(unsigned long long a, unsigned long long b)
-{
-	union ull_union au = {.ull = a};
-	union ull_union bu = {.ull = b};
-
-	if (au.ui.high < bu.ui.high)
-		return 0;
-	else if (au.ui.high > bu.ui.high)
-		return 2;
-	if (au.ui.low < bu.ui.low)
-		return 0;
-	else if (au.ui.low > bu.ui.low)
-		return 2;
-	return 1;
-}