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
33struct debug_info {
34#ifdef CONFIG_HAVE_HW_BREAKPOINT
35	struct perf_event	*hbp[ARM_MAX_HBP_SLOTS];
36#endif
37};
38
39struct 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 */
72struct task_struct;
73
74/* Free all resources held by a thread. */
75extern void release_thread(struct task_struct *);
76
77unsigned 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
110static 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
119static 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