[PATCH 1/7] MIPS: Implement setjmp

[Heinrich Schuchardt]

Am 17. Mai 2024 18:32:52 MESZ schrieb Jiaxun Yang <jiaxun.yang at flygoat.com>:
>Implement setjmp with o32/n64 ABI's standard stack frame.
>Note that those two ABIs slightly disagreed on placement of
>registers so they are being implemented in two different
>files.
>
>Signed-off-by: Jiaxun Yang <jiaxun.yang at flygoat.com>
>---
> arch/mips/include/asm/setjmp.h | 36 +++++++++++++++++++++++++++
> arch/mips/lib/Makefile         |  2 ++
> arch/mips/lib/setjmp32.S       | 51 ++++++++++++++++++++++++++++++++++++++
> arch/mips/lib/setjmp64.S       | 56 ++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 145 insertions(+)
>
>diff --git a/arch/mips/include/asm/setjmp.h b/arch/mips/include/asm/setjmp.h
>new file mode 100644
>index 000000000000..afa2ffb007e6
>--- /dev/null
>+++ b/arch/mips/include/asm/setjmp.h
>@@ -0,0 +1,36 @@
>+/* SPDX-License-Identifier: GPL-2.0+ */
>+/*
>+ * Copyright (c) 2024 Jiaxun Yang <jiaxun.yang at flygoat.com>
>+ */
>+
>+#ifndef _SETJMP_H_
>+#define _SETJMP_H_	1
>+
>+/*
>+ * This really should be opaque, but the EFI implementation wrongly
>+ * assumes that a 'struct jmp_buf_data' is defined.
>+ */
>+#if __mips == 64
>+struct jmp_buf_data {
>+	unsigned long ra;
>+	unsigned long sp;
>+	unsigned long fp;
>+	unsigned long gp;
>+	unsigned long s_regs[8];	/* s0 - s7 */
>+};
>+#else
>+struct jmp_buf_data {
>+	unsigned long ra;
>+	unsigned long sp;
>+	unsigned long s_regs[8];	/* s0 - s7 */
>+	unsigned long fp;
>+	unsigned long gp;
>+};

As the jumpbuffer is only used inside U-Boot we should be able to use the same register sequence independant of the bitness.

Best regards

Heinrich

>+#endif
>+
>+typedef struct jmp_buf_data jmp_buf[1];
>+
>+int setjmp(jmp_buf jmp);
>+void longjmp(jmp_buf jmp, int ret);
>+
>+#endif /* _SETJMP_H_ */
>diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile
>index 1621cc9a1ff9..e36dfd0547b5 100644
>--- a/arch/mips/lib/Makefile
>+++ b/arch/mips/lib/Makefile
>@@ -10,6 +10,8 @@ obj-y	+= reloc.o
> obj-y	+= stack.o
> obj-y	+= traps.o
> 
>+obj-$(CONFIG_32BIT) += setjmp32.o
>+obj-$(CONFIG_64BIT) += setjmp64.o
> obj-$(CONFIG_CMD_BOOTM) += bootm.o
> obj-$(CONFIG_CMD_GO) += boot.o
> obj-$(CONFIG_SPL_BUILD) += spl.o
>diff --git a/arch/mips/lib/setjmp32.S b/arch/mips/lib/setjmp32.S
>new file mode 100644
>index 000000000000..4a2661d29249
>--- /dev/null
>+++ b/arch/mips/lib/setjmp32.S
>@@ -0,0 +1,51 @@
>+/* SPDX-License-Identifier: GPL-2.0+ */
>+/*
>+ * Copyright (c) 2024 Jiaxun Yang <jiaxun.yang at flygoat.com>
>+ */
>+
>+#include <linux/linkage.h>
>+#include <asm/regdef.h>
>+
>+.pushsection .text.setjmp, "ax"
>+ENTRY(setjmp)
>+	sw      ra,  0(a0)
>+	sw      sp,  4(a0)
>+	sw      s0,  8(a0)
>+	sw      s1, 12(a0)
>+	sw      s2, 16(a0)
>+	sw      s3, 20(a0)
>+	sw      s4, 24(a0)
>+	sw      s5, 28(a0)
>+	sw      s6, 32(a0)
>+	sw      s7, 36(a0)
>+	sw      fp, 40(a0)
>+	sw      gp, 44(a0)
>+
>+	move	v0, zero
>+	jr	ra
>+ENDPROC(setjmp)
>+.popsection
>+
>+.pushsection .text.longjmp, "ax"
>+ENTRY(longjmp)
>+	lw      ra,  0(a0)
>+	lw      sp,  4(a0)
>+	lw      s0,  8(a0)
>+	lw      s1, 12(a0)
>+	lw      s2, 16(a0)
>+	lw      s3, 20(a0)
>+	lw      s4, 24(a0)
>+	lw      s5, 28(a0)
>+	lw      s6, 32(a0)
>+	lw      s7, 36(a0)
>+	lw      fp, 40(a0)
>+	lw      gp, 44(a0)
>+
>+	beqz	a1, 1f
>+	move	v0, a1
>+	jr	ra
>+1:
>+	li	v0, 1
>+	jr	ra
>+ENDPROC(longjmp)
>+.popsection
>diff --git a/arch/mips/lib/setjmp64.S b/arch/mips/lib/setjmp64.S
>new file mode 100644
>index 000000000000..6f615bb10014
>--- /dev/null
>+++ b/arch/mips/lib/setjmp64.S
>@@ -0,0 +1,56 @@
>+/* SPDX-License-Identifier: GPL-2.0+ */
>+/*
>+ * Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.
>+ * Copyright (c) 2017 Lemote Co.Ltd
>+ * 	Author: Heiher <r at hev.cc>
>+ * Copyright (c) 2024 Jiaxun Yang <jiaxun.yang at flygoat.com>
>+ */
>+
>+#include <linux/linkage.h>
>+#include <asm/regdef.h>
>+
>+.pushsection .text.setjmp, "ax"
>+ENTRY(setjmp)
>+	sd	ra, 0x00(a0)
>+	sd	sp, 0x08(a0)
>+	sd	fp, 0x10(a0)
>+	sd	gp, 0x18(a0)
>+
>+	sd	s0, 0x20(a0)
>+	sd	s1, 0x28(a0)
>+	sd	s2, 0x30(a0)
>+	sd	s3, 0x38(a0)
>+	sd	s4, 0x40(a0)
>+	sd	s5, 0x48(a0)
>+	sd	s6, 0x50(a0)
>+	sd	s7, 0x58(a0)
>+
>+	move	v0, zero
>+	jr	ra
>+ENDPROC(setjmp)
>+.popsection
>+
>+.pushsection .text.longjmp, "ax"
>+ENTRY(longjmp)
>+	ld	ra, 0x00(a0)
>+	ld	sp, 0x08(a0)
>+	ld	fp, 0x10(a0)
>+	ld	gp, 0x18(a0)
>+
>+	ld	s0, 0x20(a0)
>+	ld	s1, 0x28(a0)
>+	ld	s2, 0x30(a0)
>+	ld	s3, 0x38(a0)
>+	ld	s4, 0x40(a0)
>+	ld	s5, 0x48(a0)
>+	ld	s6, 0x50(a0)
>+	ld	s7, 0x58(a0)
>+
>+	beqz	a1, 1f
>+	move	v0, a1
>+	jr	ra
>+1:
>+	li	v0, 1
>+	jr	ra
>+ENDPROC(longjmp)
>+.popsection
>