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 static inline int in_kernel_text(unsigned long addr)
21 {
22 	if (addr >= (unsigned long)_stext && addr < (unsigned long)__init_end)
23 		return 1;
24 
25 	return 0;
26 }
27 
28 static inline unsigned long kernel_toc_addr(void)
29 {
30 	/* Defined by the linker, see vmlinux.lds.S */
31 	extern unsigned long __toc_start;
32 
33 	/*
34 	 * The TOC register (r2) points 32kB into the TOC, so that 64kB of
35 	 * the TOC can be addressed using a single machine instruction.
36 	 */
37 	return (unsigned long)(&__toc_start) + 0x8000UL;
38 }
39 
40 static inline int overlaps_interrupt_vector_text(unsigned long start,
41 							unsigned long end)
42 {
43 	unsigned long real_start, real_end;
44 	real_start = __start_interrupts - _stext;
45 	real_end = __end_interrupts - _stext;
46 
47 	return start < (unsigned long)__va(real_end) &&
48 		(unsigned long)__va(real_start) < end;
49 }
50 
51 static inline int overlaps_kernel_text(unsigned long start, unsigned long end)
52 {
53 	return start < (unsigned long)__init_end &&
54 		(unsigned long)_stext < end;
55 }
56 
57 static inline int overlaps_kvm_tmp(unsigned long start, unsigned long end)
58 {
59 #ifdef CONFIG_KVM_GUEST
60 	extern char kvm_tmp[];
61 	return start < (unsigned long)kvm_tmp &&
62 		(unsigned long)&kvm_tmp[1024 * 1024] < end;
63 #else
64 	return 0;
65 #endif
66 }
67 
68 #ifdef PPC64_ELF_ABI_v1
69 
70 #define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
71 
72 #undef dereference_function_descriptor
73 static inline void *dereference_function_descriptor(void *ptr)
74 {
75 	struct ppc64_opd_entry *desc = ptr;
76 	void *p;
77 
78 	if (!probe_kernel_address(&desc->funcaddr, p))
79 		ptr = p;
80 	return ptr;
81 }
82 
83 #undef dereference_kernel_function_descriptor
84 static inline void *dereference_kernel_function_descriptor(void *ptr)
85 {
86 	if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
87 		return ptr;
88 
89 	return dereference_function_descriptor(ptr);
90 }
91 #endif /* PPC64_ELF_ABI_v1 */
92 
93 #endif
94 
95 #endif /* __KERNEL__ */
96 #endif	/* _ASM_POWERPC_SECTIONS_H */
97