xref: /openbmc/linux/arch/arm/include/asm/processor.h (revision 2c684d89)
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 #define INIT_THREAD  {	}
49 
50 #ifdef CONFIG_MMU
51 #define nommu_start_thread(regs) do { } while (0)
52 #else
53 #define nommu_start_thread(regs) regs->ARM_r10 = current->mm->start_data
54 #endif
55 
56 #define start_thread(regs,pc,sp)					\
57 ({									\
58 	memset(regs->uregs, 0, sizeof(regs->uregs));			\
59 	if (current->personality & ADDR_LIMIT_32BIT)			\
60 		regs->ARM_cpsr = USR_MODE;				\
61 	else								\
62 		regs->ARM_cpsr = USR26_MODE;				\
63 	if (elf_hwcap & HWCAP_THUMB && pc & 1)				\
64 		regs->ARM_cpsr |= PSR_T_BIT;				\
65 	regs->ARM_cpsr |= PSR_ENDSTATE;					\
66 	regs->ARM_pc = pc & ~1;		/* pc */			\
67 	regs->ARM_sp = sp;		/* sp */			\
68 	nommu_start_thread(regs);					\
69 })
70 
71 /* Forward declaration, a strange C thing */
72 struct task_struct;
73 
74 /* Free all resources held by a thread. */
75 extern void release_thread(struct task_struct *);
76 
77 unsigned long get_wchan(struct task_struct *p);
78 
79 #if __LINUX_ARM_ARCH__ == 6 || defined(CONFIG_ARM_ERRATA_754327)
80 #define cpu_relax()			smp_mb()
81 #else
82 #define cpu_relax()			barrier()
83 #endif
84 
85 #define cpu_relax_lowlatency()                cpu_relax()
86 
87 #define task_pt_regs(p) \
88 	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
89 
90 #define KSTK_EIP(tsk)	task_pt_regs(tsk)->ARM_pc
91 #define KSTK_ESP(tsk)	task_pt_regs(tsk)->ARM_sp
92 
93 #ifdef CONFIG_SMP
94 #define __ALT_SMP_ASM(smp, up)						\
95 	"9998:	" smp "\n"						\
96 	"	.pushsection \".alt.smp.init\", \"a\"\n"		\
97 	"	.long	9998b\n"					\
98 	"	" up "\n"						\
99 	"	.popsection\n"
100 #else
101 #define __ALT_SMP_ASM(smp, up)	up
102 #endif
103 
104 /*
105  * Prefetching support - only ARMv5.
106  */
107 #if __LINUX_ARM_ARCH__ >= 5
108 
109 #define ARCH_HAS_PREFETCH
110 static inline void prefetch(const void *ptr)
111 {
112 	__asm__ __volatile__(
113 		"pld\t%a0"
114 		:: "p" (ptr));
115 }
116 
117 #if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
118 #define ARCH_HAS_PREFETCHW
119 static inline void prefetchw(const void *ptr)
120 {
121 	__asm__ __volatile__(
122 		".arch_extension	mp\n"
123 		__ALT_SMP_ASM(
124 			WASM(pldw)		"\t%a0",
125 			WASM(pld)		"\t%a0"
126 		)
127 		:: "p" (ptr));
128 }
129 #endif
130 #endif
131 
132 #define HAVE_ARCH_PICK_MMAP_LAYOUT
133 
134 #endif
135 
136 #endif /* __ASM_ARM_PROCESSOR_H */
137