xref: /linux/arch/arm64/include/asm/processor.h (revision 7056741fd9fc14a65608549a4657cf5178f05f63)
1 /*
2  * Based on arch/arm/include/asm/processor.h
3  *
4  * Copyright (C) 1995-1999 Russell King
5  * Copyright (C) 2012 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 #ifndef __ASM_PROCESSOR_H
20 #define __ASM_PROCESSOR_H
21 
22 /*
23  * Default implementation of macro that returns current
24  * instruction pointer ("program counter").
25  */
26 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
27 
28 #ifdef __KERNEL__
29 
30 #include <linux/string.h>
31 
32 #include <asm/fpsimd.h>
33 #include <asm/hw_breakpoint.h>
34 #include <asm/ptrace.h>
35 #include <asm/types.h>
36 
37 #ifdef __KERNEL__
38 #define STACK_TOP_MAX		TASK_SIZE_64
39 #ifdef CONFIG_COMPAT
40 #define AARCH32_VECTORS_BASE	0xffff0000
41 #define STACK_TOP		(test_thread_flag(TIF_32BIT) ? \
42 				AARCH32_VECTORS_BASE : STACK_TOP_MAX)
43 #else
44 #define STACK_TOP		STACK_TOP_MAX
45 #endif /* CONFIG_COMPAT */
46 #endif /* __KERNEL__ */
47 
48 struct debug_info {
49 	/* Have we suspended stepping by a debugger? */
50 	int			suspended_step;
51 	/* Allow breakpoints and watchpoints to be disabled for this thread. */
52 	int			bps_disabled;
53 	int			wps_disabled;
54 	/* Hardware breakpoints pinned to this task. */
55 	struct perf_event	*hbp_break[ARM_MAX_BRP];
56 	struct perf_event	*hbp_watch[ARM_MAX_WRP];
57 };
58 
59 struct cpu_context {
60 	unsigned long x19;
61 	unsigned long x20;
62 	unsigned long x21;
63 	unsigned long x22;
64 	unsigned long x23;
65 	unsigned long x24;
66 	unsigned long x25;
67 	unsigned long x26;
68 	unsigned long x27;
69 	unsigned long x28;
70 	unsigned long fp;
71 	unsigned long sp;
72 	unsigned long pc;
73 };
74 
75 struct thread_struct {
76 	struct cpu_context	cpu_context;	/* cpu context */
77 	unsigned long		tp_value;
78 	struct fpsimd_state	fpsimd_state;
79 	unsigned long		fault_address;	/* fault info */
80 	struct debug_info	debug;		/* debugging */
81 };
82 
83 #define INIT_THREAD  {	}
84 
85 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
86 {
87 	memset(regs, 0, sizeof(*regs));
88 	regs->syscallno = ~0UL;
89 	regs->pc = pc;
90 }
91 
92 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
93 				unsigned long sp)
94 {
95 	unsigned long *stack = (unsigned long *)sp;
96 
97 	start_thread_common(regs, pc);
98 	regs->pstate = PSR_MODE_EL0t;
99 	regs->sp = sp;
100 	regs->regs[2] = stack[2];	/* x2 (envp) */
101 	regs->regs[1] = stack[1];	/* x1 (argv) */
102 	regs->regs[0] = stack[0];	/* x0 (argc) */
103 }
104 
105 #ifdef CONFIG_COMPAT
106 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
107 				       unsigned long sp)
108 {
109 	unsigned int *stack = (unsigned int *)sp;
110 
111 	start_thread_common(regs, pc);
112 	regs->pstate = COMPAT_PSR_MODE_USR;
113 	if (pc & 1)
114 		regs->pstate |= COMPAT_PSR_T_BIT;
115 	regs->compat_sp = sp;
116 	regs->regs[2] = stack[2];	/* x2 (envp) */
117 	regs->regs[1] = stack[1];	/* x1 (argv) */
118 	regs->regs[0] = stack[0];	/* x0 (argc) */
119 }
120 #endif
121 
122 /* Forward declaration, a strange C thing */
123 struct task_struct;
124 
125 /* Free all resources held by a thread. */
126 extern void release_thread(struct task_struct *);
127 
128 /* Prepare to copy thread state - unlazy all lazy status */
129 #define prepare_to_copy(tsk)	do { } while (0)
130 
131 unsigned long get_wchan(struct task_struct *p);
132 
133 #define cpu_relax()			barrier()
134 
135 /* Thread switching */
136 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
137 					 struct task_struct *next);
138 
139 /*
140  * Create a new kernel thread
141  */
142 extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
143 
144 #define task_pt_regs(p) \
145 	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
146 
147 #define KSTK_EIP(tsk)	task_pt_regs(tsk)->pc
148 #define KSTK_ESP(tsk)	task_pt_regs(tsk)->sp
149 
150 /*
151  * Prefetching support
152  */
153 #define ARCH_HAS_PREFETCH
154 static inline void prefetch(const void *ptr)
155 {
156 	asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
157 }
158 
159 #define ARCH_HAS_PREFETCHW
160 static inline void prefetchw(const void *ptr)
161 {
162 	asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
163 }
164 
165 #define ARCH_HAS_SPINLOCK_PREFETCH
166 static inline void spin_lock_prefetch(const void *x)
167 {
168 	prefetchw(x);
169 }
170 
171 #define HAVE_ARCH_PICK_MMAP_LAYOUT
172 
173 #endif
174 
175 #endif /* __ASM_PROCESSOR_H */
176