x86: Add implementations of setjmp() and longjmp()

Bring in these functions from Linux v4.4. They will be needed for EFI loader
support.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
index 2667e0b..f5b8c9e 100644 (file)
--- a/arch/x86/cpu/Makefile
+++ b/arch/x86/cpu/Makefile
@@ -10,7 +10,7 @@
 
 extra-y        = start.o
 obj-$(CONFIG_X86_RESET_VECTOR) += resetvec.o start16.o
-obj-y  += interrupts.o cpu.o cpu_x86.o call64.o
+obj-y  += interrupts.o cpu.o cpu_x86.o call64.o setjmp.o
 
 AFLAGS_REMOVE_call32.o := -mregparm=3 \
        $(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32)

diff --git a/arch/x86/cpu/setjmp.S b/arch/x86/cpu/setjmp.S
new file mode 100644 (file)
index 0000000..2ea1c6c
--- /dev/null
+++ b/arch/x86/cpu/setjmp.S
@@ -0,0 +1,61 @@
+/*
+ * Written by H. Peter Anvin <hpa@zytor.com>
+ * Brought in from Linux v4.4 and modified for U-Boot
+ * From Linux arch/um/sys-i386/setjmp.S
+ *
+ * SPDX-License-Identifier:    GPL-2.0
+ */
+
+#define _REGPARM
+
+/*
+ * The jmp_buf is assumed to contain the following, in order:
+ *     %ebx
+ *     %esp
+ *     %ebp
+ *     %esi
+ *     %edi
+ *     <return address>
+ */
+
+       .text
+       .align 4
+       .globl setjmp
+       .type setjmp, @function
+setjmp:
+#ifdef _REGPARM
+       movl %eax, %edx
+#else
+       movl 4(%esp), %edx
+#endif
+       popl %ecx               /* Return address, and adjust the stack */
+       xorl %eax, %eax         /* Return value */
+       movl %ebx, (%edx)
+       movl %esp, 4(%edx)      /* Post-return %esp! */
+       pushl %ecx              /* Make the call/return stack happy */
+       movl %ebp, 8(%edx)
+       movl %esi, 12(%edx)
+       movl %edi, 16(%edx)
+       movl %ecx, 20(%edx)     /* Return address */
+       ret
+
+       /* Provide function size if needed */
+       .size setjmp, .-setjmp
+
+       .align 4
+       .globl longjmp
+       .type longjmp, @function
+longjmp:
+#ifdef _REGPARM
+       xchgl %eax, %edx
+#else
+       movl 4(%esp), %edx      /* jmp_ptr address */
+#endif
+       movl (%edx), %ebx
+       movl 4(%edx), %esp
+       movl 8(%edx), %ebp
+       movl 12(%edx), %esi
+       movl 16(%edx), %edi
+       jmp *20(%edx)
+
+       .size longjmp, .-longjmp

diff --git a/arch/x86/include/asm/setjmp.h b/arch/x86/include/asm/setjmp.h
new file mode 100644 (file)
index 0000000..1feaa89
--- /dev/null
+++ b/arch/x86/include/asm/setjmp.h
@@ -0,0 +1,24 @@
+/*
+ * Written by H. Peter Anvin <hpa@zytor.com>
+ * Brought in from Linux v4.4 and modified for U-Boot
+ * From Linux arch/um/sys-i386/setjmp.S
+ *
+ * SPDX-License-Identifier:    GPL-2.0
+ */
+
+#ifndef __setjmp_h
+#define __setjmp_h
+
+struct jmp_buf_data {
+       unsigned int __ebx;
+       unsigned int __esp;
+       unsigned int __ebp;
+       unsigned int __esi;
+       unsigned int __edi;
+       unsigned int __eip;
+};
+
+int setjmp(struct jmp_buf_data *jmp_buf);
+void longjmp(struct jmp_buf_data *jmp_buf, int val);
+
+#endif