xref: /openbmc/linux/arch/arm/include/asm/processor.h (revision 9be08a27)
1 /*
2  *  arch/arm/include/asm/processor.h
3  *
4  *  Copyright (C) 1995-1999 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #ifndef __ASM_ARM_PROCESSOR_H
12 #define __ASM_ARM_PROCESSOR_H
13 
14 /*
15  * Default implementation of macro that returns current
16  * instruction pointer ("program counter").
17  */
18 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
19 
20 #ifdef __KERNEL__
21 
22 #include <asm/hw_breakpoint.h>
23 #include <asm/ptrace.h>
24 #include <asm/types.h>
25 #include <asm/unified.h>
26 
27 #ifdef __KERNEL__
28 #define STACK_TOP	((current->personality & ADDR_LIMIT_32BIT) ? \
29 			 TASK_SIZE : TASK_SIZE_26)
30 #define STACK_TOP_MAX	TASK_SIZE
31 #endif
32 
33 struct debug_info {
34 #ifdef CONFIG_HAVE_HW_BREAKPOINT
35 	struct perf_event	*hbp[ARM_MAX_HBP_SLOTS];
36 #endif
37 };
38 
39 struct thread_struct {
40 							/* fault info	  */
41 	unsigned long		address;
42 	unsigned long		trap_no;
43 	unsigned long		error_code;
44 							/* debugging	  */
45 	struct debug_info	debug;
46 };
47 
48 /*
49  * Everything usercopied to/from thread_struct is statically-sized, so
50  * no hardened usercopy whitelist is needed.
51  */
52 static inline void arch_thread_struct_whitelist(unsigned long *offset,
53 						unsigned long *size)
54 {
55 	*offset = *size = 0;
56 }
57 
58 #define INIT_THREAD  {	}
59 
60 #define start_thread(regs,pc,sp)					\
61 ({									\
62 	unsigned long r7, r8, r9;					\
63 									\
64 	if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC)) {			\
65 		r7 = regs->ARM_r7;					\
66 		r8 = regs->ARM_r8;					\
67 		r9 = regs->ARM_r9;					\
68 	}								\
69 	memset(regs->uregs, 0, sizeof(regs->uregs));			\
70 	if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC) &&			\
71 	    current->personality & FDPIC_FUNCPTRS) {			\
72 		regs->ARM_r7 = r7;					\
73 		regs->ARM_r8 = r8;					\
74 		regs->ARM_r9 = r9;					\
75 		regs->ARM_r10 = current->mm->start_data;		\
76 	} else if (!IS_ENABLED(CONFIG_MMU))				\
77 		regs->ARM_r10 = current->mm->start_data;		\
78 	if (current->personality & ADDR_LIMIT_32BIT)			\
79 		regs->ARM_cpsr = USR_MODE;				\
80 	else								\
81 		regs->ARM_cpsr = USR26_MODE;				\
82 	if (elf_hwcap & HWCAP_THUMB && pc & 1)				\
83 		regs->ARM_cpsr |= PSR_T_BIT;				\
84 	regs->ARM_cpsr |= PSR_ENDSTATE;					\
85 	regs->ARM_pc = pc & ~1;		/* pc */			\
86 	regs->ARM_sp = sp;		/* sp */			\
87 })
88 
89 /* Forward declaration, a strange C thing */
90 struct task_struct;
91 
92 /* Free all resources held by a thread. */
93 extern void release_thread(struct task_struct *);
94 
95 unsigned long get_wchan(struct task_struct *p);
96 
97 #if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)
98 #define cpu_relax()			smp_mb()
99 #else
100 #define cpu_relax()			barrier()
101 #endif
102 
103 #define task_pt_regs(p) \
104 	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
105 
106 #define KSTK_EIP(tsk)	task_pt_regs(tsk)->ARM_pc
107 #define KSTK_ESP(tsk)	task_pt_regs(tsk)->ARM_sp
108 
109 #ifdef CONFIG_SMP
110 #define __ALT_SMP_ASM(smp, up)						\
111 	"9998:	" smp "\n"						\
112 	"	.pushsection \".alt.smp.init\", \"a\"\n"		\
113 	"	.long	9998b\n"					\
114 	"	" up "\n"						\
115 	"	.popsection\n"
116 #else
117 #define __ALT_SMP_ASM(smp, up)	up
118 #endif
119 
120 /*
121  * Prefetching support - only ARMv5.
122  */
123 #if __LINUX_ARM_ARCH__ >= 5
124 
125 #define ARCH_HAS_PREFETCH
126 static inline void prefetch(const void *ptr)
127 {
128 	__asm__ __volatile__(
129 		"pld\t%a0"
130 		:: "p" (ptr));
131 }
132 
133 #if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
134 #define ARCH_HAS_PREFETCHW
135 static inline void prefetchw(const void *ptr)
136 {
137 	__asm__ __volatile__(
138 		".arch_extension	mp\n"
139 		__ALT_SMP_ASM(
140 			WASM(pldw)		"\t%a0",
141 			WASM(pld)		"\t%a0"
142 		)
143 		:: "p" (ptr));
144 }
145 #endif
146 #endif
147 
148 #define HAVE_ARCH_PICK_MMAP_LAYOUT
149 
150 #endif
151 
152 #endif /* __ASM_ARM_PROCESSOR_H */
153