xref: /openbmc/linux/arch/arm64/include/asm/processor.h (revision cfbb9be8)
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 #define TASK_SIZE_64		(UL(1) << VA_BITS)
23 
24 #define KERNEL_DS	UL(-1)
25 #define USER_DS		(TASK_SIZE_64 - 1)
26 
27 #ifndef __ASSEMBLY__
28 
29 /*
30  * Default implementation of macro that returns current
31  * instruction pointer ("program counter").
32  */
33 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
34 
35 #ifdef __KERNEL__
36 
37 #include <linux/string.h>
38 
39 #include <asm/alternative.h>
40 #include <asm/fpsimd.h>
41 #include <asm/hw_breakpoint.h>
42 #include <asm/lse.h>
43 #include <asm/pgtable-hwdef.h>
44 #include <asm/ptrace.h>
45 #include <asm/types.h>
46 
47 /*
48  * TASK_SIZE - the maximum size of a user space task.
49  * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
50  */
51 #ifdef CONFIG_COMPAT
52 #define TASK_SIZE_32		UL(0x100000000)
53 #define TASK_SIZE		(test_thread_flag(TIF_32BIT) ? \
54 				TASK_SIZE_32 : TASK_SIZE_64)
55 #define TASK_SIZE_OF(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT) ? \
56 				TASK_SIZE_32 : TASK_SIZE_64)
57 #else
58 #define TASK_SIZE		TASK_SIZE_64
59 #endif /* CONFIG_COMPAT */
60 
61 #define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 4))
62 
63 #define STACK_TOP_MAX		TASK_SIZE_64
64 #ifdef CONFIG_COMPAT
65 #define AARCH32_VECTORS_BASE	0xffff0000
66 #define STACK_TOP		(test_thread_flag(TIF_32BIT) ? \
67 				AARCH32_VECTORS_BASE : STACK_TOP_MAX)
68 #else
69 #define STACK_TOP		STACK_TOP_MAX
70 #endif /* CONFIG_COMPAT */
71 
72 extern phys_addr_t arm64_dma_phys_limit;
73 #define ARCH_LOW_ADDRESS_LIMIT	(arm64_dma_phys_limit - 1)
74 
75 struct debug_info {
76 #ifdef CONFIG_HAVE_HW_BREAKPOINT
77 	/* Have we suspended stepping by a debugger? */
78 	int			suspended_step;
79 	/* Allow breakpoints and watchpoints to be disabled for this thread. */
80 	int			bps_disabled;
81 	int			wps_disabled;
82 	/* Hardware breakpoints pinned to this task. */
83 	struct perf_event	*hbp_break[ARM_MAX_BRP];
84 	struct perf_event	*hbp_watch[ARM_MAX_WRP];
85 #endif
86 };
87 
88 struct cpu_context {
89 	unsigned long x19;
90 	unsigned long x20;
91 	unsigned long x21;
92 	unsigned long x22;
93 	unsigned long x23;
94 	unsigned long x24;
95 	unsigned long x25;
96 	unsigned long x26;
97 	unsigned long x27;
98 	unsigned long x28;
99 	unsigned long fp;
100 	unsigned long sp;
101 	unsigned long pc;
102 };
103 
104 struct thread_struct {
105 	struct cpu_context	cpu_context;	/* cpu context */
106 	unsigned long		tp_value;	/* TLS register */
107 #ifdef CONFIG_COMPAT
108 	unsigned long		tp2_value;
109 #endif
110 	struct fpsimd_state	fpsimd_state;
111 	void			*sve_state;	/* SVE registers, if any */
112 	unsigned int		sve_vl;		/* SVE vector length */
113 	unsigned int		sve_vl_onexec;	/* SVE vl after next exec */
114 	unsigned long		fault_address;	/* fault info */
115 	unsigned long		fault_code;	/* ESR_EL1 value */
116 	struct debug_info	debug;		/* debugging */
117 };
118 
119 /*
120  * Everything usercopied to/from thread_struct is statically-sized, so
121  * no hardened usercopy whitelist is needed.
122  */
123 static inline void arch_thread_struct_whitelist(unsigned long *offset,
124 						unsigned long *size)
125 {
126 	*offset = *size = 0;
127 }
128 
129 #ifdef CONFIG_COMPAT
130 #define task_user_tls(t)						\
131 ({									\
132 	unsigned long *__tls;						\
133 	if (is_compat_thread(task_thread_info(t)))			\
134 		__tls = &(t)->thread.tp2_value;				\
135 	else								\
136 		__tls = &(t)->thread.tp_value;				\
137 	__tls;								\
138  })
139 #else
140 #define task_user_tls(t)	(&(t)->thread.tp_value)
141 #endif
142 
143 /* Sync TPIDR_EL0 back to thread_struct for current */
144 void tls_preserve_current_state(void);
145 
146 #define INIT_THREAD  {	}
147 
148 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
149 {
150 	memset(regs, 0, sizeof(*regs));
151 	forget_syscall(regs);
152 	regs->pc = pc;
153 }
154 
155 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
156 				unsigned long sp)
157 {
158 	start_thread_common(regs, pc);
159 	regs->pstate = PSR_MODE_EL0t;
160 	regs->sp = sp;
161 }
162 
163 #ifdef CONFIG_COMPAT
164 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
165 				       unsigned long sp)
166 {
167 	start_thread_common(regs, pc);
168 	regs->pstate = COMPAT_PSR_MODE_USR;
169 	if (pc & 1)
170 		regs->pstate |= COMPAT_PSR_T_BIT;
171 
172 #ifdef __AARCH64EB__
173 	regs->pstate |= COMPAT_PSR_E_BIT;
174 #endif
175 
176 	regs->compat_sp = sp;
177 }
178 #endif
179 
180 /* Forward declaration, a strange C thing */
181 struct task_struct;
182 
183 /* Free all resources held by a thread. */
184 extern void release_thread(struct task_struct *);
185 
186 unsigned long get_wchan(struct task_struct *p);
187 
188 static inline void cpu_relax(void)
189 {
190 	asm volatile("yield" ::: "memory");
191 }
192 
193 /* Thread switching */
194 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
195 					 struct task_struct *next);
196 
197 #define task_pt_regs(p) \
198 	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
199 
200 #define KSTK_EIP(tsk)	((unsigned long)task_pt_regs(tsk)->pc)
201 #define KSTK_ESP(tsk)	user_stack_pointer(task_pt_regs(tsk))
202 
203 /*
204  * Prefetching support
205  */
206 #define ARCH_HAS_PREFETCH
207 static inline void prefetch(const void *ptr)
208 {
209 	asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
210 }
211 
212 #define ARCH_HAS_PREFETCHW
213 static inline void prefetchw(const void *ptr)
214 {
215 	asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
216 }
217 
218 #define ARCH_HAS_SPINLOCK_PREFETCH
219 static inline void spin_lock_prefetch(const void *ptr)
220 {
221 	asm volatile(ARM64_LSE_ATOMIC_INSN(
222 		     "prfm pstl1strm, %a0",
223 		     "nop") : : "p" (ptr));
224 }
225 
226 #define HAVE_ARCH_PICK_MMAP_LAYOUT
227 
228 #endif
229 
230 int cpu_enable_pan(void *__unused);
231 int cpu_enable_cache_maint_trap(void *__unused);
232 int cpu_clear_disr(void *__unused);
233 
234 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
235 #define SVE_SET_VL(arg)	sve_set_current_vl(arg)
236 #define SVE_GET_VL()	sve_get_current_vl()
237 
238 #endif /* __ASSEMBLY__ */
239 #endif /* __ASM_PROCESSOR_H */
240