1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_SECTIONS_H
3 #define _ASM_POWERPC_SECTIONS_H
4 #ifdef __KERNEL__
5 
6 #include <linux/elf.h>
7 #include <linux/uaccess.h>
8 #include <asm-generic/sections.h>
9 
10 extern char __head_end[];
11 
12 #ifdef __powerpc64__
13 
14 extern char __start_interrupts[];
15 extern char __end_interrupts[];
16 
17 extern char __prom_init_toc_start[];
18 extern char __prom_init_toc_end[];
19 
20 #ifdef CONFIG_PPC_POWERNV
21 extern char start_real_trampolines[];
22 extern char end_real_trampolines[];
23 extern char start_virt_trampolines[];
24 extern char end_virt_trampolines[];
25 #endif
26 
27 static inline int in_kernel_text(unsigned long addr)
28 {
29 	if (addr >= (unsigned long)_stext && addr < (unsigned long)__init_end)
30 		return 1;
31 
32 	return 0;
33 }
34 
35 static inline unsigned long kernel_toc_addr(void)
36 {
37 	/* Defined by the linker, see vmlinux.lds.S */
38 	extern unsigned long __toc_start;
39 
40 	/*
41 	 * The TOC register (r2) points 32kB into the TOC, so that 64kB of
42 	 * the TOC can be addressed using a single machine instruction.
43 	 */
44 	return (unsigned long)(&__toc_start) + 0x8000UL;
45 }
46 
47 static inline int overlaps_interrupt_vector_text(unsigned long start,
48 							unsigned long end)
49 {
50 	unsigned long real_start, real_end;
51 	real_start = __start_interrupts - _stext;
52 	real_end = __end_interrupts - _stext;
53 
54 	return start < (unsigned long)__va(real_end) &&
55 		(unsigned long)__va(real_start) < end;
56 }
57 
58 static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
59 {
60 	return start < (unsigned long)__init_end &&
61 		(unsigned long)_stext < end;
62 }
63 
64 #ifdef PPC64_ELF_ABI_v1
65 
66 #define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
67 
68 #undef dereference_function_descriptor
69 static inline void *dereference_function_descriptor(void *ptr)
70 {
71 	struct ppc64_opd_entry *desc = ptr;
72 	void *p;
73 
74 	if (!probe_kernel_address(&desc->funcaddr, p))
75 		ptr = p;
76 	return ptr;
77 }
78 
79 #undef dereference_kernel_function_descriptor
80 static inline void *dereference_kernel_function_descriptor(void *ptr)
81 {
82 	if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
83 		return ptr;
84 
85 	return dereference_function_descriptor(ptr);
86 }
87 #endif /* PPC64_ELF_ABI_v1 */
88 
89 #endif
90 
91 #endif /* __KERNEL__ */
92 #endif	/* _ASM_POWERPC_SECTIONS_H */
93