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) << 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 #include <linux/thread_info.h>
30
31 #include <vdso/processor.h>
32
33 #include <asm/alternative.h>
34 #include <asm/cpufeature.h>
35 #include <asm/hw_breakpoint.h>
36 #include <asm/kasan.h>
37 #include <asm/lse.h>
38 #include <asm/pgtable-hwdef.h>
39 #include <asm/pointer_auth.h>
40 #include <asm/ptrace.h>
41 #include <asm/spectre.h>
42 #include <asm/types.h>
43
44 /*
45 * TASK_SIZE - the maximum size of a user space task.
46 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
47 */
48
49 #define DEFAULT_MAP_WINDOW_64 (UL(1) << VA_BITS_MIN)
50 #define TASK_SIZE_64 (UL(1) << vabits_actual)
51
52 #ifdef CONFIG_COMPAT
53 #if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
54 /*
55 * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
56 * by the compat vectors page.
57 */
58 #define TASK_SIZE_32 UL(0x100000000)
59 #else
60 #define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE)
61 #endif /* CONFIG_ARM64_64K_PAGES */
62 #define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
63 TASK_SIZE_32 : TASK_SIZE_64)
64 #define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
65 TASK_SIZE_32 : TASK_SIZE_64)
66 #define DEFAULT_MAP_WINDOW (test_thread_flag(TIF_32BIT) ? \
67 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
68 #else
69 #define TASK_SIZE TASK_SIZE_64
70 #define DEFAULT_MAP_WINDOW DEFAULT_MAP_WINDOW_64
71 #endif /* CONFIG_COMPAT */
72
73 #ifdef CONFIG_ARM64_FORCE_52BIT
74 #define STACK_TOP_MAX TASK_SIZE_64
75 #define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
76 #else
77 #define STACK_TOP_MAX DEFAULT_MAP_WINDOW_64
78 #define TASK_UNMAPPED_BASE (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
79 #endif /* CONFIG_ARM64_FORCE_52BIT */
80
81 #ifdef CONFIG_COMPAT
82 #define AARCH32_VECTORS_BASE 0xffff0000
83 #define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
84 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
85 #else
86 #define STACK_TOP STACK_TOP_MAX
87 #endif /* CONFIG_COMPAT */
88
89 #ifndef CONFIG_ARM64_FORCE_52BIT
90 #define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
91 DEFAULT_MAP_WINDOW)
92
93 #define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
94 base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
95 base)
96 #endif /* CONFIG_ARM64_FORCE_52BIT */
97
98 extern phys_addr_t arm64_dma_phys_limit;
99 #define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1)
100
101 struct debug_info {
102 #ifdef CONFIG_HAVE_HW_BREAKPOINT
103 /* Have we suspended stepping by a debugger? */
104 int suspended_step;
105 /* Allow breakpoints and watchpoints to be disabled for this thread. */
106 int bps_disabled;
107 int wps_disabled;
108 /* Hardware breakpoints pinned to this task. */
109 struct perf_event *hbp_break[ARM_MAX_BRP];
110 struct perf_event *hbp_watch[ARM_MAX_WRP];
111 #endif
112 };
113
114 struct cpu_context {
115 unsigned long x19;
116 unsigned long x20;
117 unsigned long x21;
118 unsigned long x22;
119 unsigned long x23;
120 unsigned long x24;
121 unsigned long x25;
122 unsigned long x26;
123 unsigned long x27;
124 unsigned long x28;
125 unsigned long fp;
126 unsigned long sp;
127 unsigned long pc;
128 };
129
130 struct thread_struct {
131 struct cpu_context cpu_context; /* cpu context */
132
133 /*
134 * Whitelisted fields for hardened usercopy:
135 * Maintainers must ensure manually that this contains no
136 * implicit padding.
137 */
138 struct {
139 unsigned long tp_value; /* TLS register */
140 unsigned long tp2_value;
141 struct user_fpsimd_state fpsimd_state;
142 } uw;
143
144 unsigned int fpsimd_cpu;
145 void *sve_state; /* SVE registers, if any */
146 unsigned int sve_vl; /* SVE vector length */
147 unsigned int sve_vl_onexec; /* SVE vl after next exec */
148 unsigned long fault_address; /* fault info */
149 unsigned long fault_code; /* ESR_EL1 value */
150 struct debug_info debug; /* debugging */
151 #ifdef CONFIG_ARM64_PTR_AUTH
152 struct ptrauth_keys_user keys_user;
153 struct ptrauth_keys_kernel keys_kernel;
154 #endif
155 #ifdef CONFIG_ARM64_MTE
156 u64 sctlr_tcf0;
157 u64 gcr_user_incl;
158 #endif
159 };
160
arch_thread_struct_whitelist(unsigned long * offset,unsigned long * size)161 static inline void arch_thread_struct_whitelist(unsigned long *offset,
162 unsigned long *size)
163 {
164 /* Verify that there is no padding among the whitelisted fields: */
165 BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
166 sizeof_field(struct thread_struct, uw.tp_value) +
167 sizeof_field(struct thread_struct, uw.tp2_value) +
168 sizeof_field(struct thread_struct, uw.fpsimd_state));
169
170 *offset = offsetof(struct thread_struct, uw);
171 *size = sizeof_field(struct thread_struct, uw);
172 }
173
174 #ifdef CONFIG_COMPAT
175 #define task_user_tls(t) \
176 ({ \
177 unsigned long *__tls; \
178 if (is_compat_thread(task_thread_info(t))) \
179 __tls = &(t)->thread.uw.tp2_value; \
180 else \
181 __tls = &(t)->thread.uw.tp_value; \
182 __tls; \
183 })
184 #else
185 #define task_user_tls(t) (&(t)->thread.uw.tp_value)
186 #endif
187
188 /* Sync TPIDR_EL0 back to thread_struct for current */
189 void tls_preserve_current_state(void);
190
191 #define INIT_THREAD { \
192 .fpsimd_cpu = NR_CPUS, \
193 }
194
start_thread_common(struct pt_regs * regs,unsigned long pc)195 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
196 {
197 memset(regs, 0, sizeof(*regs));
198 forget_syscall(regs);
199 regs->pc = pc;
200
201 if (system_uses_irq_prio_masking())
202 regs->pmr_save = GIC_PRIO_IRQON;
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 spectre_v4_enable_task_mitigation(current);
211 regs->sp = sp;
212 }
213
214 #ifdef CONFIG_COMPAT
compat_start_thread(struct pt_regs * regs,unsigned long pc,unsigned long sp)215 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
216 unsigned long sp)
217 {
218 start_thread_common(regs, pc);
219 regs->pstate = PSR_AA32_MODE_USR;
220 if (pc & 1)
221 regs->pstate |= PSR_AA32_T_BIT;
222
223 #ifdef __AARCH64EB__
224 regs->pstate |= PSR_AA32_E_BIT;
225 #endif
226
227 spectre_v4_enable_task_mitigation(current);
228 regs->compat_sp = sp;
229 }
230 #endif
231
is_ttbr0_addr(unsigned long addr)232 static inline bool is_ttbr0_addr(unsigned long addr)
233 {
234 /* entry assembly clears tags for TTBR0 addrs */
235 return addr < TASK_SIZE;
236 }
237
is_ttbr1_addr(unsigned long addr)238 static inline bool is_ttbr1_addr(unsigned long addr)
239 {
240 /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
241 return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
242 }
243
244 /* Forward declaration, a strange C thing */
245 struct task_struct;
246
247 /* Free all resources held by a thread. */
248 extern void release_thread(struct task_struct *);
249
250 unsigned long get_wchan(struct task_struct *p);
251
252 /* Thread switching */
253 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
254 struct task_struct *next);
255
256 #define task_pt_regs(p) \
257 ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
258
259 #define KSTK_EIP(tsk) ((unsigned long)task_pt_regs(tsk)->pc)
260 #define KSTK_ESP(tsk) user_stack_pointer(task_pt_regs(tsk))
261
262 /*
263 * Prefetching support
264 */
265 #define ARCH_HAS_PREFETCH
prefetch(const void * ptr)266 static inline void prefetch(const void *ptr)
267 {
268 asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
269 }
270
271 #define ARCH_HAS_PREFETCHW
prefetchw(const void * ptr)272 static inline void prefetchw(const void *ptr)
273 {
274 asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
275 }
276
277 #define ARCH_HAS_SPINLOCK_PREFETCH
spin_lock_prefetch(const void * ptr)278 static inline void spin_lock_prefetch(const void *ptr)
279 {
280 asm volatile(ARM64_LSE_ATOMIC_INSN(
281 "prfm pstl1strm, %a0",
282 "nop") : : "p" (ptr));
283 }
284
285 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
286 extern void __init minsigstksz_setup(void);
287
288 /*
289 * Not at the top of the file due to a direct #include cycle between
290 * <asm/fpsimd.h> and <asm/processor.h>. Deferring this #include
291 * ensures that contents of processor.h are visible to fpsimd.h even if
292 * processor.h is included first.
293 *
294 * These prctl helpers are the only things in this file that require
295 * fpsimd.h. The core code expects them to be in this header.
296 */
297 #include <asm/fpsimd.h>
298
299 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
300 #define SVE_SET_VL(arg) sve_set_current_vl(arg)
301 #define SVE_GET_VL() sve_get_current_vl()
302
303 /* PR_PAC_RESET_KEYS prctl */
304 #define PAC_RESET_KEYS(tsk, arg) ptrauth_prctl_reset_keys(tsk, arg)
305
306 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
307 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
308 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
309 long get_tagged_addr_ctrl(struct task_struct *task);
310 #define SET_TAGGED_ADDR_CTRL(arg) set_tagged_addr_ctrl(current, arg)
311 #define GET_TAGGED_ADDR_CTRL() get_tagged_addr_ctrl(current)
312 #endif
313
314 /*
315 * For CONFIG_GCC_PLUGIN_STACKLEAK
316 *
317 * These need to be macros because otherwise we get stuck in a nightmare
318 * of header definitions for the use of task_stack_page.
319 */
320
321 #define current_top_of_stack() \
322 ({ \
323 struct stack_info _info; \
324 BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info)); \
325 _info.high; \
326 })
327 #define on_thread_stack() (on_task_stack(current, current_stack_pointer, NULL))
328
329 #endif /* __ASSEMBLY__ */
330 #endif /* __ASM_PROCESSOR_H */
331