[PATCH v2] xtensa: add __bswap{si,di}2 helpers

From: Max Filippov
Date: Fri May 12 2023 - 05:02:24 EST


gcc-13 may generate calls for __bswap{si,di}2. This breaks the kernel
build when optimization for size is selected. Add __bswap{si,di}2
helpers to fix that.

Fixes: 19c5699f9aff ("xtensa: don't link with libgcc")
Signed-off-by: Max Filippov <jcmvbkbc@xxxxxxxxx>
---
Changes v1->v2:
- add declarations and EXPORT_SYMBOL

arch/xtensa/kernel/xtensa_ksyms.c | 4 ++++
arch/xtensa/lib/Makefile | 2 +-
arch/xtensa/lib/bswapdi2.S | 21 +++++++++++++++++++++
arch/xtensa/lib/bswapsi2.S | 16 ++++++++++++++++
4 files changed, 42 insertions(+), 1 deletion(-)
create mode 100644 arch/xtensa/lib/bswapdi2.S
create mode 100644 arch/xtensa/lib/bswapsi2.S

diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c
index 2a31b1ab0c9f..17a7ef86fd0d 100644
--- a/arch/xtensa/kernel/xtensa_ksyms.c
+++ b/arch/xtensa/kernel/xtensa_ksyms.c
@@ -56,6 +56,8 @@ EXPORT_SYMBOL(empty_zero_page);
*/
extern long long __ashrdi3(long long, int);
extern long long __ashldi3(long long, int);
+extern long long __bswapdi2(long long);
+extern int __bswapsi2(int);
extern long long __lshrdi3(long long, int);
extern int __divsi3(int, int);
extern int __modsi3(int, int);
@@ -66,6 +68,8 @@ extern unsigned long long __umulsidi3(unsigned int, unsigned int);

EXPORT_SYMBOL(__ashldi3);
EXPORT_SYMBOL(__ashrdi3);
+EXPORT_SYMBOL(__bswapdi2);
+EXPORT_SYMBOL(__bswapsi2);
EXPORT_SYMBOL(__lshrdi3);
EXPORT_SYMBOL(__divsi3);
EXPORT_SYMBOL(__modsi3);
diff --git a/arch/xtensa/lib/Makefile b/arch/xtensa/lib/Makefile
index 7ecef0519a27..c9c2614188f7 100644
--- a/arch/xtensa/lib/Makefile
+++ b/arch/xtensa/lib/Makefile
@@ -4,7 +4,7 @@
#

lib-y += memcopy.o memset.o checksum.o \
- ashldi3.o ashrdi3.o lshrdi3.o \
+ ashldi3.o ashrdi3.o bswapdi2.o bswapsi2.o lshrdi3.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
diff --git a/arch/xtensa/lib/bswapdi2.S b/arch/xtensa/lib/bswapdi2.S
new file mode 100644
index 000000000000..d8e52e05eba6
--- /dev/null
+++ b/arch/xtensa/lib/bswapdi2.S
@@ -0,0 +1,21 @@
+/* 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>
+
+ENTRY(__bswapdi2)
+
+ abi_entry_default
+ ssai 8
+ srli a4, a2, 16
+ src a4, a4, a2
+ src a4, a4, a4
+ src a4, a2, a4
+ srli a2, a3, 16
+ src a2, a2, a3
+ src a2, a2, a2
+ src a2, a3, a2
+ mov a3, a4
+ abi_ret_default
+
+ENDPROC(__bswapdi2)
diff --git a/arch/xtensa/lib/bswapsi2.S b/arch/xtensa/lib/bswapsi2.S
new file mode 100644
index 000000000000..9c1de1344f79
--- /dev/null
+++ b/arch/xtensa/lib/bswapsi2.S
@@ -0,0 +1,16 @@
+/* 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>
+
+ENTRY(__bswapsi2)
+
+ abi_entry_default
+ ssai 8
+ srli a3, a2, 16
+ src a3, a3, a2
+ src a3, a3, a3
+ src a2, a2, a3
+ abi_ret_default
+
+ENDPROC(__bswapsi2)
--
2.30.2