[PATCH v3 10/16] powerpc: Implement initjmp/setjmp/longjmp

[Ahmad Fatoum]

From: Sascha Hauer <s.hauer at pengutronix.de>

Implementation has been taken from newlib as this is much simpler than
the glibc version.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 arch/powerpc/Kconfig              |  1 +
 arch/powerpc/include/asm/setjmp.h | 21 ++++++++
 arch/powerpc/lib/Makefile         |  2 +-
 arch/powerpc/lib/setjmp.S         | 86 +++++++++++++++++++++++++++++++
 4 files changed, 109 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/include/asm/setjmp.h
 create mode 100644 arch/powerpc/lib/setjmp.S

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 90ec7b1702e9..376c1bf42b5e 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -6,6 +6,7 @@ config PPC
 	select HAS_CACHE
 	select GENERIC_FIND_NEXT_BIT
 	select OFTREE
+	select HAS_ARCH_SJLJ
 	default y
 
 choice
diff --git a/arch/powerpc/include/asm/setjmp.h b/arch/powerpc/include/asm/setjmp.h
new file mode 100644
index 000000000000..c558415c99d9
--- /dev/null
+++ b/arch/powerpc/include/asm/setjmp.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2017 Theobroma Systems Design und Consulting GmbH
+ * (C) Copyright 2016 Alexander Graf <agraf at suse.de>
+ */
+
+#ifndef _SETJMP_H_
+#define _SETJMP_H_	1
+
+#include <asm/types.h>
+
+typedef struct __jmp_buf_internal_tag {
+	long int __regs[24];
+} jmp_buf[1];
+
+int setjmp(jmp_buf jmp) __attribute__((returns_twice));
+void longjmp(jmp_buf jmp, int ret) __attribute__((noreturn));
+
+int initjmp(jmp_buf jmp, void __noreturn (*func)(void), void *stack_top);
+
+#endif /* _SETJMP_H_ */
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index ba2f078b6277..405351c19929 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -9,4 +9,4 @@ obj-$(CONFIG_CMD_BOOTM) += ppclinux.o
 obj-$(CONFIG_MODULES) += module.o
 obj-y += crtsavres.o
 obj-y += reloc.o
-
+obj-y += setjmp.o
diff --git a/arch/powerpc/lib/setjmp.S b/arch/powerpc/lib/setjmp.S
new file mode 100644
index 000000000000..021a57eebc3c
--- /dev/null
+++ b/arch/powerpc/lib/setjmp.S
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/*
+ * This is a simple version of setjmp and longjmp for the PowerPC.
+ * Ian Lance Taylor, Cygnus Support, 9 Feb 1994.
+ */
+
+#include <linux/linkage.h>
+#include <asm/ppc_asm.tmpl>
+
+ENTRY(setjmp)
+	addi	r3,r3,7		# align to 8 byte boundary
+	rlwinm	r3,r3,0,0,28
+	stw	r1,0(r3)	# offset 0
+	stwu	r2,4(r3)	# offset 4
+	stwu	r13,4(r3)	# offset 8
+	stwu	r14,4(r3)	# offset 12
+	stwu	r15,4(r3)	# offset 16
+	stwu	r16,4(r3)	# offset 20
+	stwu	r17,4(r3)	# offset 24
+	stwu	r18,4(r3)	# offset 28
+	stwu	r19,4(r3)	# offset 32
+	stwu	r20,4(r3)	# offset 36
+	stwu	r21,4(r3)	# offset 40
+	stwu	r22,4(r3)	# offset 44
+	stwu	r23,4(r3)	# offset 48
+	stwu	r24,4(r3)	# offset 52
+	stwu	r25,4(r3)	# offset 56
+	stwu	r26,4(r3)	# offset 60
+	stwu	r27,4(r3)	# offset 64
+	stwu	r28,4(r3)	# offset 68
+	stwu	r29,4(r3)	# offset 72
+	stwu	r30,4(r3)	# offset 76
+	stwu	r31,4(r3)	# offset 80
+	mflr	r4
+	stwu	r4,4(r3)	# offset 84
+	mfcr	r4
+	stwu	r4,4(r3)	# offset 88
+
+	li	r3,0
+	blr
+END(setjmp)
+
+ENTRY(longjmp)
+	addi	r3,r3,7		# align to 8 byte boundary
+	rlwinm	r3,r3,0,0,28
+	lwz	r1,0(r3)	# offset 0
+	lwzu	r2,4(r3)	# offset 4
+	lwzu	r13,4(r3)	# offset 8
+	lwzu	r14,4(r3)	# offset 12
+	lwzu	r15,4(r3)	# offset 16
+	lwzu	r16,4(r3)	# offset 20
+	lwzu	r17,4(r3)	# offset 24
+	lwzu	r18,4(r3)	# offset 28
+	lwzu	r19,4(r3)	# offset 32
+	lwzu	r20,4(r3)	# offset 36
+	lwzu	r21,4(r3)	# offset 40
+	lwzu	r22,4(r3)	# offset 44
+	lwzu	r23,4(r3)	# offset 48
+	lwzu	r24,4(r3)	# offset 52
+	lwzu	r25,4(r3)	# offset 56
+	lwzu	r26,4(r3)	# offset 60
+	lwzu	r27,4(r3)	# offset 64
+	lwzu	r28,4(r3)	# offset 68
+	lwzu	r29,4(r3)	# offset 72
+	lwzu	r30,4(r3)	# offset 76
+	lwzu	r31,4(r3)	# offset 80
+	lwzu	r5,4(r3)	# offset 84
+	mtlr	r5
+	lwzu	r5,4(r3)	# offset 88
+	mtcrf	255,r5
+
+	mr.	r3,r4
+	bclr+	4,2
+	li	r3,1
+	blr
+END(longjmp)
+
+ENTRY(initjmp)
+	addi	r3,r3,7		# align to 8 byte boundary
+	rlwinm	r3,r3,0,0,28
+	stw	r5,0(r3)	# offset 0
+	stwu	r4,88(r3)	# offset 88
+	li	r3,0
+	blr
+END(initjmp)
-- 
2.29.2