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 
9 #include <asm-generic/sections.h>
10 
11 extern char __head_end[];
12 
13 #ifdef __powerpc64__
14 
15 extern char __start_interrupts[];
16 extern char __end_interrupts[];
17 
18 extern char __prom_init_toc_start[];
19 extern char __prom_init_toc_end[];
20 
21 #ifdef CONFIG_PPC_POWERNV
22 extern char start_real_trampolines[];
23 extern char end_real_trampolines[];
24 extern char start_virt_trampolines[];
25 extern char end_virt_trampolines[];
26 #endif
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 #ifdef PPC64_ELF_ABI_v1
58 
59 #define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
60 
61 #undef dereference_function_descriptor
62 static inline void *dereference_function_descriptor(void *ptr)
63 {
64 	struct ppc64_opd_entry *desc = ptr;
65 	void *p;
66 
67 	if (!get_kernel_nofault(p, (void *)&desc->funcaddr))
68 		ptr = p;
69 	return ptr;
70 }
71 
72 #undef dereference_kernel_function_descriptor
73 static inline void *dereference_kernel_function_descriptor(void *ptr)
74 {
75 	if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
76 		return ptr;
77 
78 	return dereference_function_descriptor(ptr);
79 }
80 #endif /* PPC64_ELF_ABI_v1 */
81 
82 #endif
83 
84 #endif /* __KERNEL__ */
85 #endif	/* _ASM_POWERPC_SECTIONS_H */
86