1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Based on arch/arm/include/asm/processor.h
4 *
5 * Copyright (C) 1995-1999 Russell King
6 * Copyright (C) 2012 ARM Ltd.
7 */
8 #ifndef __ASM_PROCESSOR_H
9 #define __ASM_PROCESSOR_H
10
11 #define KERNEL_DS UL(-1)
12 #define USER_DS ((UL(1) << MAX_USER_VA_BITS) - 1)
13
14 /*
15 * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is
16 * no point in shifting all network buffers by 2 bytes just to make some IP
17 * header fields appear aligned in memory, potentially sacrificing some DMA
18 * performance on some platforms.
19 */
20 #define NET_IP_ALIGN 0
21
22 #ifndef __ASSEMBLY__
23
24 #include <linux/build_bug.h>
25 #include <linux/cache.h>
26 #include <linux/init.h>
27 #include <linux/stddef.h>
28 #include <linux/string.h>
29
30 #include <asm/alternative.h>
31 #include <asm/cpufeature.h>
32 #include <asm/hw_breakpoint.h>
33 #include <asm/lse.h>
34 #include <asm/pgtable-hwdef.h>
35 #include <asm/pointer_auth.h>
36 #include <asm/ptrace.h>
37 #include <asm/types.h>
38
39 /*
40 * TASK_SIZE - the maximum size of a user space task.
41 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
42 */
43
44 #define DEFAULT_MAP_WINDOW_64 (UL(1) << VA_BITS_MIN)
45 #define TASK_SIZE_64 (UL(1) << vabits_actual)
46
47 #ifdef CONFIG_COMPAT
48 #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
49 /*
50 * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
51 * by the compat vectors page.
52 */
53 #define TASK_SIZE_32 UL(0x100000000)
54 #else
55 #define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE)
56 #endif /* CONFIG_ARM64_64K_PAGES */
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 #define DEFAULT_MAP_WINDOW (test_thread_flag(TIF_32BIT) ? \
62 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
63 #else
64 #define TASK_SIZE TASK_SIZE_64
65 #define DEFAULT_MAP_WINDOW DEFAULT_MAP_WINDOW_64
66 #endif /* CONFIG_COMPAT */
67
68 #ifdef CONFIG_ARM64_FORCE_52BIT
69 #define STACK_TOP_MAX TASK_SIZE_64
70 #define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
71 #else
72 #define STACK_TOP_MAX DEFAULT_MAP_WINDOW_64
73 #define TASK_UNMAPPED_BASE (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
74 #endif /* CONFIG_ARM64_FORCE_52BIT */
75
76 #ifdef CONFIG_COMPAT
77 #define AARCH32_VECTORS_BASE 0xffff0000
78 #define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
79 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
80 #else
81 #define STACK_TOP STACK_TOP_MAX
82 #endif /* CONFIG_COMPAT */
83
84 #ifndef CONFIG_ARM64_FORCE_52BIT
85 #define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
86 DEFAULT_MAP_WINDOW)
87
88 #define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
89 base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
90 base)
91 #endif /* CONFIG_ARM64_FORCE_52BIT */
92
93 extern phys_addr_t arm64_dma_phys_limit;
94 #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1)
95
96 struct debug_info {
97 #ifdef CONFIG_HAVE_HW_BREAKPOINT
98 /* Have we suspended stepping by a debugger? */
99 int suspended_step;
100 /* Allow breakpoints and watchpoints to be disabled for this thread. */
101 int bps_disabled;
102 int wps_disabled;
103 /* Hardware breakpoints pinned to this task. */
104 struct perf_event *hbp_break[ARM_MAX_BRP];
105 struct perf_event *hbp_watch[ARM_MAX_WRP];
106 #endif
107 };
108
109 struct cpu_context {
110 unsigned long x19;
111 unsigned long x20;
112 unsigned long x21;
113 unsigned long x22;
114 unsigned long x23;
115 unsigned long x24;
116 unsigned long x25;
117 unsigned long x26;
118 unsigned long x27;
119 unsigned long x28;
120 unsigned long fp;
121 unsigned long sp;
122 unsigned long pc;
123 };
124
125 struct thread_struct {
126 struct cpu_context cpu_context; /* cpu context */
127
128 /*
129 * Whitelisted fields for hardened usercopy:
130 * Maintainers must ensure manually that this contains no
131 * implicit padding.
132 */
133 struct {
134 unsigned long tp_value; /* TLS register */
135 unsigned long tp2_value;
136 struct user_fpsimd_state fpsimd_state;
137 } uw;
138
139 unsigned int fpsimd_cpu;
140 void *sve_state; /* SVE registers, if any */
141 unsigned int sve_vl; /* SVE vector length */
142 unsigned int sve_vl_onexec; /* SVE vl after next exec */
143 unsigned long fault_address; /* fault info */
144 unsigned long fault_code; /* ESR_EL1 value */
145 struct debug_info debug; /* debugging */
146 #ifdef CONFIG_ARM64_PTR_AUTH
147 struct ptrauth_keys keys_user;
148 #endif
149 };
150
arch_thread_struct_whitelist(unsigned long * offset,unsigned long * size)151 static inline void arch_thread_struct_whitelist(unsigned long *offset,
152 unsigned long *size)
153 {
154 /* Verify that there is no padding among the whitelisted fields: */
155 BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
156 sizeof_field(struct thread_struct, uw.tp_value) +
157 sizeof_field(struct thread_struct, uw.tp2_value) +
158 sizeof_field(struct thread_struct, uw.fpsimd_state));
159
160 *offset = offsetof(struct thread_struct, uw);
161 *size = sizeof_field(struct thread_struct, uw);
162 }
163
164 #ifdef CONFIG_COMPAT
165 #define task_user_tls(t) \
166 ({ \
167 unsigned long *__tls; \
168 if (is_compat_thread(task_thread_info(t))) \
169 __tls = &(t)->thread.uw.tp2_value; \
170 else \
171 __tls = &(t)->thread.uw.tp_value; \
172 __tls; \
173 })
174 #else
175 #define task_user_tls(t) (&(t)->thread.uw.tp_value)
176 #endif
177
178 /* Sync TPIDR_EL0 back to thread_struct for current */
179 void tls_preserve_current_state(void);
180
181 #define INIT_THREAD { \
182 .fpsimd_cpu = NR_CPUS, \
183 }
184
start_thread_common(struct pt_regs * regs,unsigned long pc)185 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
186 {
187 memset(regs, 0, sizeof(*regs));
188 forget_syscall(regs);
189 regs->pc = pc;
190
191 if (system_uses_irq_prio_masking())
192 regs->pmr_save = GIC_PRIO_IRQON;
193 }
194
set_ssbs_bit(struct pt_regs * regs)195 static inline void set_ssbs_bit(struct pt_regs *regs)
196 {
197 regs->pstate |= PSR_SSBS_BIT;
198 }
199
set_compat_ssbs_bit(struct pt_regs * regs)200 static inline void set_compat_ssbs_bit(struct pt_regs *regs)
201 {
202 regs->pstate |= PSR_AA32_SSBS_BIT;
203 }
204
start_thread(struct pt_regs * regs,unsigned long pc,unsigned long sp)205 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
206 unsigned long sp)
207 {
208 start_thread_common(regs, pc);
209 regs->pstate = PSR_MODE_EL0t;
210
211 if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
212 set_ssbs_bit(regs);
213
214 regs->sp = sp;
215 }
216
217 #ifdef CONFIG_COMPAT
compat_start_thread(struct pt_regs * regs,unsigned long pc,unsigned long sp)218 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
219 unsigned long sp)
220 {
221 start_thread_common(regs, pc);
222 regs->pstate = PSR_AA32_MODE_USR;
223 if (pc & 1)
224 regs->pstate |= PSR_AA32_T_BIT;
225
226 #ifdef __AARCH64EB__
227 regs->pstate |= PSR_AA32_E_BIT;
228 #endif
229
230 if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
231 set_compat_ssbs_bit(regs);
232
233 regs->compat_sp = sp;
234 }
235 #endif
236
237 /* Forward declaration, a strange C thing */
238 struct task_struct;
239
240 /* Free all resources held by a thread. */
241 extern void release_thread(struct task_struct *);
242
243 unsigned long get_wchan(struct task_struct *p);
244
cpu_relax(void)245 static inline void cpu_relax(void)
246 {
247 asm volatile("yield" ::: "memory");
248 }
249
250 /* Thread switching */
251 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
252 struct task_struct *next);
253
254 #define task_pt_regs(p) \
255 ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
256
257 #define KSTK_EIP(tsk) ((unsigned long)task_pt_regs(tsk)->pc)
258 #define KSTK_ESP(tsk) user_stack_pointer(task_pt_regs(tsk))
259
260 /*
261 * Prefetching support
262 */
263 #define ARCH_HAS_PREFETCH
prefetch(const void * ptr)264 static inline void prefetch(const void *ptr)
265 {
266 asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
267 }
268
269 #define ARCH_HAS_PREFETCHW
prefetchw(const void * ptr)270 static inline void prefetchw(const void *ptr)
271 {
272 asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
273 }
274
275 #define ARCH_HAS_SPINLOCK_PREFETCH
spin_lock_prefetch(const void * ptr)276 static inline void spin_lock_prefetch(const void *ptr)
277 {
278 asm volatile(ARM64_LSE_ATOMIC_INSN(
279 "prfm pstl1strm, %a0",
280 "nop") : : "p" (ptr));
281 }
282
283 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
284 extern void __init minsigstksz_setup(void);
285
286 /*
287 * Not at the top of the file due to a direct #include cycle between
288 * <asm/fpsimd.h> and <asm/processor.h>. Deferring this #include
289 * ensures that contents of processor.h are visible to fpsimd.h even if
290 * processor.h is included first.
291 *
292 * These prctl helpers are the only things in this file that require
293 * fpsimd.h. The core code expects them to be in this header.
294 */
295 #include <asm/fpsimd.h>
296
297 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
298 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
299 #define SVE_GET_VL() sve_get_current_vl()
300
301 /* PR_PAC_RESET_KEYS prctl */
302 #define PAC_RESET_KEYS(tsk, arg) ptrauth_prctl_reset_keys(tsk, arg)
303
304 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
305 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
306 long set_tagged_addr_ctrl(unsigned long arg);
307 long get_tagged_addr_ctrl(void);
308 #define SET_TAGGED_ADDR_CTRL(arg) set_tagged_addr_ctrl(arg)
309 #define GET_TAGGED_ADDR_CTRL() get_tagged_addr_ctrl()
310 #endif
311
312 /*
313 * For CONFIG_GCC_PLUGIN_STACKLEAK
314 *
315 * These need to be macros because otherwise we get stuck in a nightmare
316 * of header definitions for the use of task_stack_page.
317 */
318
319 #define current_top_of_stack() \
320 ({ \
321 struct stack_info _info; \
322 BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info)); \
323 _info.high; \
324 })
325 #define on_thread_stack() (on_task_stack(current, current_stack_pointer, NULL))
326
327 #endif /* __ASSEMBLY__ */
328 #endif /* __ASM_PROCESSOR_H */
329
