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/build_bug.h>
38 #include <linux/cache.h>
39 #include <linux/init.h>
40 #include <linux/stddef.h>
41 #include <linux/string.h>
42
43 #include <asm/alternative.h>
44 #include <asm/cpufeature.h>
45 #include <asm/hw_breakpoint.h>
46 #include <asm/lse.h>
47 #include <asm/pgtable-hwdef.h>
48 #include <asm/ptrace.h>
49 #include <asm/types.h>
50
51 /*
52 * TASK_SIZE - the maximum size of a user space task.
53 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
54 */
55 #ifdef CONFIG_COMPAT
56 #define TASK_SIZE_32 UL(0x100000000)
57 #define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
58 TASK_SIZE_32 : TASK_SIZE_64)
59 #define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
60 TASK_SIZE_32 : TASK_SIZE_64)
61 #else
62 #define TASK_SIZE TASK_SIZE_64
63 #endif /* CONFIG_COMPAT */
64
65 #define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
66
67 #define STACK_TOP_MAX TASK_SIZE_64
68 #ifdef CONFIG_COMPAT
69 #define AARCH32_VECTORS_BASE 0xffff0000
70 #define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
71 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
72 #else
73 #define STACK_TOP STACK_TOP_MAX
74 #endif /* CONFIG_COMPAT */
75
76 extern phys_addr_t arm64_dma_phys_limit;
77 #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1)
78
79 struct debug_info {
80 #ifdef CONFIG_HAVE_HW_BREAKPOINT
81 /* Have we suspended stepping by a debugger? */
82 int suspended_step;
83 /* Allow breakpoints and watchpoints to be disabled for this thread. */
84 int bps_disabled;
85 int wps_disabled;
86 /* Hardware breakpoints pinned to this task. */
87 struct perf_event *hbp_break[ARM_MAX_BRP];
88 struct perf_event *hbp_watch[ARM_MAX_WRP];
89 #endif
90 };
91
92 struct cpu_context {
93 unsigned long x19;
94 unsigned long x20;
95 unsigned long x21;
96 unsigned long x22;
97 unsigned long x23;
98 unsigned long x24;
99 unsigned long x25;
100 unsigned long x26;
101 unsigned long x27;
102 unsigned long x28;
103 unsigned long fp;
104 unsigned long sp;
105 unsigned long pc;
106 };
107
108 struct thread_struct {
109 struct cpu_context cpu_context; /* cpu context */
110
111 /*
112 * Whitelisted fields for hardened usercopy:
113 * Maintainers must ensure manually that this contains no
114 * implicit padding.
115 */
116 struct {
117 unsigned long tp_value; /* TLS register */
118 unsigned long tp2_value;
119 struct user_fpsimd_state fpsimd_state;
120 } uw;
121
122 unsigned int fpsimd_cpu;
123 void *sve_state; /* SVE registers, if any */
124 unsigned int sve_vl; /* SVE vector length */
125 unsigned int sve_vl_onexec; /* SVE vl after next exec */
126 unsigned long fault_address; /* fault info */
127 unsigned long fault_code; /* ESR_EL1 value */
128 struct debug_info debug; /* debugging */
129 };
130
arch_thread_struct_whitelist(unsigned long * offset,unsigned long * size)131 static inline void arch_thread_struct_whitelist(unsigned long *offset,
132 unsigned long *size)
133 {
134 /* Verify that there is no padding among the whitelisted fields: */
135 BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
136 sizeof_field(struct thread_struct, uw.tp_value) +
137 sizeof_field(struct thread_struct, uw.tp2_value) +
138 sizeof_field(struct thread_struct, uw.fpsimd_state));
139
140 *offset = offsetof(struct thread_struct, uw);
141 *size = sizeof_field(struct thread_struct, uw);
142 }
143
144 #ifdef CONFIG_COMPAT
145 #define task_user_tls(t) \
146 ({ \
147 unsigned long *__tls; \
148 if (is_compat_thread(task_thread_info(t))) \
149 __tls = &(t)->thread.uw.tp2_value; \
150 else \
151 __tls = &(t)->thread.uw.tp_value; \
152 __tls; \
153 })
154 #else
155 #define task_user_tls(t) (&(t)->thread.uw.tp_value)
156 #endif
157
158 /* Sync TPIDR_EL0 back to thread_struct for current */
159 void tls_preserve_current_state(void);
160
161 #define INIT_THREAD { \
162 .fpsimd_cpu = NR_CPUS, \
163 }
164
start_thread_common(struct pt_regs * regs,unsigned long pc)165 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
166 {
167 memset(regs, 0, sizeof(*regs));
168 forget_syscall(regs);
169 regs->pc = pc;
170 }
171
start_thread(struct pt_regs * regs,unsigned long pc,unsigned long sp)172 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
173 unsigned long sp)
174 {
175 start_thread_common(regs, pc);
176 regs->pstate = PSR_MODE_EL0t;
177 regs->sp = sp;
178 }
179
180 #ifdef CONFIG_COMPAT
compat_start_thread(struct pt_regs * regs,unsigned long pc,unsigned long sp)181 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
182 unsigned long sp)
183 {
184 start_thread_common(regs, pc);
185 regs->pstate = PSR_AA32_MODE_USR;
186 if (pc & 1)
187 regs->pstate |= PSR_AA32_T_BIT;
188
189 #ifdef __AARCH64EB__
190 regs->pstate |= PSR_AA32_E_BIT;
191 #endif
192
193 regs->compat_sp = sp;
194 }
195 #endif
196
197 /* Forward declaration, a strange C thing */
198 struct task_struct;
199
200 /* Free all resources held by a thread. */
201 extern void release_thread(struct task_struct *);
202
203 unsigned long get_wchan(struct task_struct *p);
204
cpu_relax(void)205 static inline void cpu_relax(void)
206 {
207 asm volatile("yield" ::: "memory");
208 }
209
210 /* Thread switching */
211 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
212 struct task_struct *next);
213
214 #define task_pt_regs(p) \
215 ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
216
217 #define KSTK_EIP(tsk) ((unsigned long)task_pt_regs(tsk)->pc)
218 #define KSTK_ESP(tsk) user_stack_pointer(task_pt_regs(tsk))
219
220 /*
221 * Prefetching support
222 */
223 #define ARCH_HAS_PREFETCH
prefetch(const void * ptr)224 static inline void prefetch(const void *ptr)
225 {
226 asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
227 }
228
229 #define ARCH_HAS_PREFETCHW
prefetchw(const void * ptr)230 static inline void prefetchw(const void *ptr)
231 {
232 asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
233 }
234
235 #define ARCH_HAS_SPINLOCK_PREFETCH
spin_lock_prefetch(const void * ptr)236 static inline void spin_lock_prefetch(const void *ptr)
237 {
238 asm volatile(ARM64_LSE_ATOMIC_INSN(
239 "prfm pstl1strm, %a0",
240 "nop") : : "p" (ptr));
241 }
242
243 #define HAVE_ARCH_PICK_MMAP_LAYOUT
244
245 #endif
246
247 void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused);
248 void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused);
249 void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused);
250
251 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
252 extern void __init minsigstksz_setup(void);
253
254 /*
255 * Not at the top of the file due to a direct #include cycle between
256 * <asm/fpsimd.h> and <asm/processor.h>. Deferring this #include
257 * ensures that contents of processor.h are visible to fpsimd.h even if
258 * processor.h is included first.
259 *
260 * These prctl helpers are the only things in this file that require
261 * fpsimd.h. The core code expects them to be in this header.
262 */
263 #include <asm/fpsimd.h>
264
265 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
266 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
267 #define SVE_GET_VL() sve_get_current_vl()
268
269 /*
270 * For CONFIG_GCC_PLUGIN_STACKLEAK
271 *
272 * These need to be macros because otherwise we get stuck in a nightmare
273 * of header definitions for the use of task_stack_page.
274 */
275
276 #define current_top_of_stack() \
277 ({ \
278 struct stack_info _info; \
279 BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info)); \
280 _info.high; \
281 })
282 #define on_thread_stack() (on_task_stack(current, current_stack_pointer, NULL))
283
284 #endif /* __ASSEMBLY__ */
285 #endif /* __ASM_PROCESSOR_H */
286
