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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/*
12 * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is
13 * no point in shifting all network buffers by 2 bytes just to make some IP
14 * header fields appear aligned in memory, potentially sacrificing some DMA
15 * performance on some platforms.
16 */
17#define NET_IP_ALIGN 0
18
19#ifndef __ASSEMBLY__
20
21#include <linux/build_bug.h>
22#include <linux/cache.h>
23#include <linux/init.h>
24#include <linux/stddef.h>
25#include <linux/string.h>
26#include <linux/thread_info.h>
27
28#include <vdso/processor.h>
29
30#include <asm/alternative.h>
31#include <asm/cpufeature.h>
32#include <asm/hw_breakpoint.h>
33#include <asm/kasan.h>
34#include <asm/lse.h>
35#include <asm/pgtable-hwdef.h>
36#include <asm/pointer_auth.h>
37#include <asm/ptrace.h>
38#include <asm/spectre.h>
39#include <asm/types.h>
40
41/*
42 * TASK_SIZE - the maximum size of a user space task.
43 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
44 */
45
46#define DEFAULT_MAP_WINDOW_64 (UL(1) << VA_BITS_MIN)
47#define TASK_SIZE_64 (UL(1) << vabits_actual)
48#define TASK_SIZE_MAX (UL(1) << VA_BITS)
49
50#ifdef CONFIG_COMPAT
51#if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
52/*
53 * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
54 * by the compat vectors page.
55 */
56#define TASK_SIZE_32 UL(0x100000000)
57#else
58#define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE)
59#endif /* CONFIG_ARM64_64K_PAGES */
60#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
61 TASK_SIZE_32 : TASK_SIZE_64)
62#define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
63 TASK_SIZE_32 : TASK_SIZE_64)
64#define DEFAULT_MAP_WINDOW (test_thread_flag(TIF_32BIT) ? \
65 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
66#else
67#define TASK_SIZE TASK_SIZE_64
68#define DEFAULT_MAP_WINDOW DEFAULT_MAP_WINDOW_64
69#endif /* CONFIG_COMPAT */
70
71#ifdef CONFIG_ARM64_FORCE_52BIT
72#define STACK_TOP_MAX TASK_SIZE_64
73#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
74#else
75#define STACK_TOP_MAX DEFAULT_MAP_WINDOW_64
76#define TASK_UNMAPPED_BASE (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
77#endif /* CONFIG_ARM64_FORCE_52BIT */
78
79#ifdef CONFIG_COMPAT
80#define AARCH32_VECTORS_BASE 0xffff0000
81#define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
82 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
83#else
84#define STACK_TOP STACK_TOP_MAX
85#endif /* CONFIG_COMPAT */
86
87#ifndef CONFIG_ARM64_FORCE_52BIT
88#define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
89 DEFAULT_MAP_WINDOW)
90
91#define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
92 base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
93 base)
94#endif /* CONFIG_ARM64_FORCE_52BIT */
95
96extern phys_addr_t arm64_dma_phys_limit;
97extern phys_addr_t arm64_dma32_phys_limit;
98#define ARCH_LOW_ADDRESS_LIMIT ((arm64_dma_phys_limit ? : arm64_dma32_phys_limit) - 1)
99
100struct debug_info {
101#ifdef CONFIG_HAVE_HW_BREAKPOINT
102 /* Have we suspended stepping by a debugger? */
103 int suspended_step;
104 /* Allow breakpoints and watchpoints to be disabled for this thread. */
105 int bps_disabled;
106 int wps_disabled;
107 /* Hardware breakpoints pinned to this task. */
108 struct perf_event *hbp_break[ARM_MAX_BRP];
109 struct perf_event *hbp_watch[ARM_MAX_WRP];
110#endif
111};
112
113struct cpu_context {
114 unsigned long x19;
115 unsigned long x20;
116 unsigned long x21;
117 unsigned long x22;
118 unsigned long x23;
119 unsigned long x24;
120 unsigned long x25;
121 unsigned long x26;
122 unsigned long x27;
123 unsigned long x28;
124 unsigned long fp;
125 unsigned long sp;
126 unsigned long pc;
127};
128
129struct thread_struct {
130 struct cpu_context cpu_context; /* cpu context */
131
132 /*
133 * Whitelisted fields for hardened usercopy:
134 * Maintainers must ensure manually that this contains no
135 * implicit padding.
136 */
137 struct {
138 unsigned long tp_value; /* TLS register */
139 unsigned long tp2_value;
140 struct user_fpsimd_state fpsimd_state;
141 } uw;
142
143 unsigned int fpsimd_cpu;
144 void *sve_state; /* SVE registers, if any */
145 unsigned int sve_vl; /* SVE vector length */
146 unsigned int sve_vl_onexec; /* SVE vl after next exec */
147 unsigned long fault_address; /* fault info */
148 unsigned long fault_code; /* ESR_EL1 value */
149 struct debug_info debug; /* debugging */
150#ifdef CONFIG_ARM64_PTR_AUTH
151 struct ptrauth_keys_user keys_user;
152 struct ptrauth_keys_kernel keys_kernel;
153#endif
154#ifdef CONFIG_ARM64_MTE
155 u64 sctlr_tcf0;
156 u64 gcr_user_excl;
157#endif
158};
159
160static inline void arch_thread_struct_whitelist(unsigned long *offset,
161 unsigned long *size)
162{
163 /* Verify that there is no padding among the whitelisted fields: */
164 BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
165 sizeof_field(struct thread_struct, uw.tp_value) +
166 sizeof_field(struct thread_struct, uw.tp2_value) +
167 sizeof_field(struct thread_struct, uw.fpsimd_state));
168
169 *offset = offsetof(struct thread_struct, uw);
170 *size = sizeof_field(struct thread_struct, uw);
171}
172
173#ifdef CONFIG_COMPAT
174#define task_user_tls(t) \
175({ \
176 unsigned long *__tls; \
177 if (is_compat_thread(task_thread_info(t))) \
178 __tls = &(t)->thread.uw.tp2_value; \
179 else \
180 __tls = &(t)->thread.uw.tp_value; \
181 __tls; \
182 })
183#else
184#define task_user_tls(t) (&(t)->thread.uw.tp_value)
185#endif
186
187/* Sync TPIDR_EL0 back to thread_struct for current */
188void tls_preserve_current_state(void);
189
190#define INIT_THREAD { \
191 .fpsimd_cpu = NR_CPUS, \
192}
193
194static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
195{
196 memset(regs, 0, sizeof(*regs));
197 forget_syscall(regs);
198 regs->pc = pc;
199
200 if (system_uses_irq_prio_masking())
201 regs->pmr_save = GIC_PRIO_IRQON;
202}
203
204static inline void start_thread(struct pt_regs *regs, unsigned long pc,
205 unsigned long sp)
206{
207 start_thread_common(regs, pc);
208 regs->pstate = PSR_MODE_EL0t;
209 spectre_v4_enable_task_mitigation(current);
210 regs->sp = sp;
211}
212
213#ifdef CONFIG_COMPAT
214static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
215 unsigned long sp)
216{
217 start_thread_common(regs, pc);
218 regs->pstate = PSR_AA32_MODE_USR;
219 if (pc & 1)
220 regs->pstate |= PSR_AA32_T_BIT;
221
222#ifdef __AARCH64EB__
223 regs->pstate |= PSR_AA32_E_BIT;
224#endif
225
226 spectre_v4_enable_task_mitigation(current);
227 regs->compat_sp = sp;
228}
229#endif
230
231static inline bool is_ttbr0_addr(unsigned long addr)
232{
233 /* entry assembly clears tags for TTBR0 addrs */
234 return addr < TASK_SIZE;
235}
236
237static inline bool is_ttbr1_addr(unsigned long addr)
238{
239 /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
240 return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
241}
242
243/* Forward declaration, a strange C thing */
244struct task_struct;
245
246/* Free all resources held by a thread. */
247extern void release_thread(struct task_struct *);
248
249unsigned long get_wchan(struct task_struct *p);
250
251/* Thread switching */
252extern struct task_struct *cpu_switch_to(struct task_struct *prev,
253 struct task_struct *next);
254
255#define task_pt_regs(p) \
256 ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
257
258#define KSTK_EIP(tsk) ((unsigned long)task_pt_regs(tsk)->pc)
259#define KSTK_ESP(tsk) user_stack_pointer(task_pt_regs(tsk))
260
261/*
262 * Prefetching support
263 */
264#define ARCH_HAS_PREFETCH
265static inline void prefetch(const void *ptr)
266{
267 asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
268}
269
270#define ARCH_HAS_PREFETCHW
271static inline void prefetchw(const void *ptr)
272{
273 asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
274}
275
276#define ARCH_HAS_SPINLOCK_PREFETCH
277static inline void spin_lock_prefetch(const void *ptr)
278{
279 asm volatile(ARM64_LSE_ATOMIC_INSN(
280 "prfm pstl1strm, %a0",
281 "nop") : : "p" (ptr));
282}
283
284extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
285extern void __init minsigstksz_setup(void);
286
287/*
288 * Not at the top of the file due to a direct #include cycle between
289 * <asm/fpsimd.h> and <asm/processor.h>. Deferring this #include
290 * ensures that contents of processor.h are visible to fpsimd.h even if
291 * processor.h is included first.
292 *
293 * These prctl helpers are the only things in this file that require
294 * fpsimd.h. The core code expects them to be in this header.
295 */
296#include <asm/fpsimd.h>
297
298/* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
299#define SVE_SET_VL(arg) sve_set_current_vl(arg)
300#define SVE_GET_VL() sve_get_current_vl()
301
302/* PR_PAC_RESET_KEYS prctl */
303#define PAC_RESET_KEYS(tsk, arg) ptrauth_prctl_reset_keys(tsk, arg)
304
305#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
306/* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
307long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
308long get_tagged_addr_ctrl(struct task_struct *task);
309#define SET_TAGGED_ADDR_CTRL(arg) set_tagged_addr_ctrl(current, arg)
310#define GET_TAGGED_ADDR_CTRL() get_tagged_addr_ctrl(current)
311#endif
312
313/*
314 * For CONFIG_GCC_PLUGIN_STACKLEAK
315 *
316 * These need to be macros because otherwise we get stuck in a nightmare
317 * of header definitions for the use of task_stack_page.
318 */
319
320#define current_top_of_stack() \
321({ \
322 struct stack_info _info; \
323 BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info)); \
324 _info.high; \
325})
326#define on_thread_stack() (on_task_stack(current, current_stack_pointer, NULL))
327
328#endif /* __ASSEMBLY__ */
329#endif /* __ASM_PROCESSOR_H */