MIPS: Use generic GCC library routines from lib/

The commit b35cd988 ("lib: Add shared copies of some GCC library
routines") makes it possible to share generic GCC library routines by
several architectures.

This commit removes several generic GCC library routines from
arch/mips/lib/ in favour of similar routines from lib/.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
[Matt Redfearn] Use GENERIC_LIB_* named Kconfig entries
Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/19051/Signed-off-by: James Hogan <jhogan@kernel.org>

arch/mips/Kconfig

@@ -22,6 +22,11 @@ config MIPS
 	select GENERIC_CPU_AUTOPROBE
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
+	select GENERIC_LIB_ASHLDI3
+	select GENERIC_LIB_ASHRDI3
+	select GENERIC_LIB_CMPDI2
+	select GENERIC_LIB_LSHRDI3
+	select GENERIC_LIB_UCMPDI2
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
 	select GENERIC_SMP_IDLE_THREAD

arch/mips/lib/Makefile

@@ -16,5 +16,4 @@ obj-$(CONFIG_CPU_R3000)		+= r3k_dump_tlb.o
 obj-$(CONFIG_CPU_TX39XX)	+= r3k_dump_tlb.o
 
 # libgcc-style stuff needed in the kernel
-obj-y += ashldi3.o ashrdi3.o bswapsi.o bswapdi.o cmpdi2.o lshrdi3.o multi3.o \
-	 ucmpdi2.o
+obj-y += bswapsi.o bswapdi.o multi3.o

arch/mips/lib/ashldi3.c

-// SPDX-License-Identifier: GPL-2.0
-#include <linux/export.h>
-
-#include "libgcc.h"
-
-long long notrace __ashldi3(long long u, word_type b)
-{
-	DWunion uu, w;
-	word_type bm;
-
-	if (b == 0)
-		return u;
-
-	uu.ll = u;
-	bm = 32 - b;
-
-	if (bm <= 0) {
-		w.s.low = 0;
-		w.s.high = (unsigned int) uu.s.low << -bm;
-	} else {
-		const unsigned int carries = (unsigned int) uu.s.low >> bm;
-
-		w.s.low = (unsigned int) uu.s.low << b;
-		w.s.high = ((unsigned int) uu.s.high << b) | carries;
-	}
-
-	return w.ll;
-}
-
-EXPORT_SYMBOL(__ashldi3);

arch/mips/lib/ashrdi3.c

-// SPDX-License-Identifier: GPL-2.0
-#include <linux/export.h>
-
-#include "libgcc.h"
-
-long long notrace __ashrdi3(long long u, word_type b)
-{
-	DWunion uu, w;
-	word_type bm;
-
-	if (b == 0)
-		return u;
-
-	uu.ll = u;
-	bm = 32 - b;
-
-	if (bm <= 0) {
-		/* w.s.high = 1..1 or 0..0 */
-		w.s.high =
-		    uu.s.high >> 31;
-		w.s.low = uu.s.high >> -bm;
-	} else {
-		const unsigned int carries = (unsigned int) uu.s.high << bm;
-
-		w.s.high = uu.s.high >> b;
-		w.s.low = ((unsigned int) uu.s.low >> b) | carries;
-	}
-
-	return w.ll;
-}
-
-EXPORT_SYMBOL(__ashrdi3);

arch/mips/lib/cmpdi2.c

-// SPDX-License-Identifier: GPL-2.0
-#include <linux/export.h>
-
-#include "libgcc.h"
-
-word_type notrace __cmpdi2(long long a, long long b)
-{
-	const DWunion au = {
-		.ll = a
-	};
-	const DWunion bu = {
-		.ll = b
-	};
-
-	if (au.s.high < bu.s.high)
-		return 0;
-	else if (au.s.high > bu.s.high)
-		return 2;
-
-	if ((unsigned int) au.s.low < (unsigned int) bu.s.low)
-		return 0;
-	else if ((unsigned int) au.s.low > (unsigned int) bu.s.low)
-		return 2;
-
-	return 1;
-}
-
-EXPORT_SYMBOL(__cmpdi2);

arch/mips/lib/lshrdi3.c

-// SPDX-License-Identifier: GPL-2.0
-#include <linux/export.h>
-
-#include "libgcc.h"
-
-long long notrace __lshrdi3(long long u, word_type b)
-{
-	DWunion uu, w;
-	word_type bm;
-
-	if (b == 0)
-		return u;
-
-	uu.ll = u;
-	bm = 32 - b;
-
-	if (bm <= 0) {
-		w.s.high = 0;
-		w.s.low = (unsigned int) uu.s.high >> -bm;
-	} else {
-		const unsigned int carries = (unsigned int) uu.s.high << bm;
-
-		w.s.high = (unsigned int) uu.s.high >> b;
-		w.s.low = ((unsigned int) uu.s.low >> b) | carries;
-	}
-
-	return w.ll;
-}
-
-EXPORT_SYMBOL(__lshrdi3);

arch/mips/lib/ucmpdi2.c

-// SPDX-License-Identifier: GPL-2.0
-#include <linux/export.h>
-
-#include "libgcc.h"
-
-word_type notrace __ucmpdi2(unsigned long long a, unsigned long long b)
-{
-	const DWunion au = {.ll = a};
-	const DWunion bu = {.ll = b};
-
-	if ((unsigned int) au.s.high < (unsigned int) bu.s.high)
-		return 0;
-	else if ((unsigned int) au.s.high > (unsigned int) bu.s.high)
-		return 2;
-	if ((unsigned int) au.s.low < (unsigned int) bu.s.low)
-		return 0;
-	else if ((unsigned int) au.s.low > (unsigned int) bu.s.low)
-		return 2;
-	return 1;
-}
-
-EXPORT_SYMBOL(__ucmpdi2);