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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#define MTE_CTRL_GCR_USER_EXCL_SHIFT 0
20#define MTE_CTRL_GCR_USER_EXCL_MASK 0xffff
21
22#define MTE_CTRL_TCF_SYNC (1UL << 16)
23#define MTE_CTRL_TCF_ASYNC (1UL << 17)
24#define MTE_CTRL_TCF_ASYMM (1UL << 18)
25
26#ifndef __ASSEMBLY__
27
28#include <linux/build_bug.h>
29#include <linux/cache.h>
30#include <linux/init.h>
31#include <linux/stddef.h>
32#include <linux/string.h>
33#include <linux/thread_info.h>
34
35#include <vdso/processor.h>
36
37#include <asm/alternative.h>
38#include <asm/cpufeature.h>
39#include <asm/hw_breakpoint.h>
40#include <asm/kasan.h>
41#include <asm/lse.h>
42#include <asm/pgtable-hwdef.h>
43#include <asm/pointer_auth.h>
44#include <asm/ptrace.h>
45#include <asm/spectre.h>
46#include <asm/types.h>
47
48/*
49 * TASK_SIZE - the maximum size of a user space task.
50 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
51 */
52
53#define DEFAULT_MAP_WINDOW_64 (UL(1) << VA_BITS_MIN)
54#define TASK_SIZE_64 (UL(1) << vabits_actual)
55#define TASK_SIZE_MAX (UL(1) << VA_BITS)
56
57#ifdef CONFIG_COMPAT
58#if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
59/*
60 * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
61 * by the compat vectors page.
62 */
63#define TASK_SIZE_32 UL(0x100000000)
64#else
65#define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE)
66#endif /* CONFIG_ARM64_64K_PAGES */
67#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
68 TASK_SIZE_32 : TASK_SIZE_64)
69#define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
70 TASK_SIZE_32 : TASK_SIZE_64)
71#define DEFAULT_MAP_WINDOW (test_thread_flag(TIF_32BIT) ? \
72 TASK_SIZE_32 : DEFAULT_MAP_WINDOW_64)
73#else
74#define TASK_SIZE TASK_SIZE_64
75#define DEFAULT_MAP_WINDOW DEFAULT_MAP_WINDOW_64
76#endif /* CONFIG_COMPAT */
77
78#ifdef CONFIG_ARM64_FORCE_52BIT
79#define STACK_TOP_MAX TASK_SIZE_64
80#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
81#else
82#define STACK_TOP_MAX DEFAULT_MAP_WINDOW_64
83#define TASK_UNMAPPED_BASE (PAGE_ALIGN(DEFAULT_MAP_WINDOW / 4))
84#endif /* CONFIG_ARM64_FORCE_52BIT */
85
86#ifdef CONFIG_COMPAT
87#define AARCH32_VECTORS_BASE 0xffff0000
88#define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
89 AARCH32_VECTORS_BASE : STACK_TOP_MAX)
90#else
91#define STACK_TOP STACK_TOP_MAX
92#endif /* CONFIG_COMPAT */
93
94#ifndef CONFIG_ARM64_FORCE_52BIT
95#define arch_get_mmap_end(addr, len, flags) \
96 (((addr) > DEFAULT_MAP_WINDOW) ? TASK_SIZE : DEFAULT_MAP_WINDOW)
97
98#define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
99 base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
100 base)
101#endif /* CONFIG_ARM64_FORCE_52BIT */
102
103extern phys_addr_t arm64_dma_phys_limit;
104#define ARCH_LOW_ADDRESS_LIMIT (arm64_dma_phys_limit - 1)
105
106struct debug_info {
107#ifdef CONFIG_HAVE_HW_BREAKPOINT
108 /* Have we suspended stepping by a debugger? */
109 int suspended_step;
110 /* Allow breakpoints and watchpoints to be disabled for this thread. */
111 int bps_disabled;
112 int wps_disabled;
113 /* Hardware breakpoints pinned to this task. */
114 struct perf_event *hbp_break[ARM_MAX_BRP];
115 struct perf_event *hbp_watch[ARM_MAX_WRP];
116#endif
117};
118
119enum vec_type {
120 ARM64_VEC_SVE = 0,
121 ARM64_VEC_SME,
122 ARM64_VEC_MAX,
123};
124
125struct cpu_context {
126 unsigned long x19;
127 unsigned long x20;
128 unsigned long x21;
129 unsigned long x22;
130 unsigned long x23;
131 unsigned long x24;
132 unsigned long x25;
133 unsigned long x26;
134 unsigned long x27;
135 unsigned long x28;
136 unsigned long fp;
137 unsigned long sp;
138 unsigned long pc;
139};
140
141struct thread_struct {
142 struct cpu_context cpu_context; /* cpu context */
143
144 /*
145 * Whitelisted fields for hardened usercopy:
146 * Maintainers must ensure manually that this contains no
147 * implicit padding.
148 */
149 struct {
150 unsigned long tp_value; /* TLS register */
151 unsigned long tp2_value;
152 struct user_fpsimd_state fpsimd_state;
153 } uw;
154
155 unsigned int fpsimd_cpu;
156 void *sve_state; /* SVE registers, if any */
157 void *za_state; /* ZA register, if any */
158 unsigned int vl[ARM64_VEC_MAX]; /* vector length */
159 unsigned int vl_onexec[ARM64_VEC_MAX]; /* vl after next exec */
160 unsigned long fault_address; /* fault info */
161 unsigned long fault_code; /* ESR_EL1 value */
162 struct debug_info debug; /* debugging */
163#ifdef CONFIG_ARM64_PTR_AUTH
164 struct ptrauth_keys_user keys_user;
165#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
166 struct ptrauth_keys_kernel keys_kernel;
167#endif
168#endif
169#ifdef CONFIG_ARM64_MTE
170 u64 mte_ctrl;
171#endif
172 u64 sctlr_user;
173 u64 svcr;
174 u64 tpidr2_el0;
175};
176
177static inline unsigned int thread_get_vl(struct thread_struct *thread,
178 enum vec_type type)
179{
180 return thread->vl[type];
181}
182
183static inline unsigned int thread_get_sve_vl(struct thread_struct *thread)
184{
185 return thread_get_vl(thread, ARM64_VEC_SVE);
186}
187
188static inline unsigned int thread_get_sme_vl(struct thread_struct *thread)
189{
190 return thread_get_vl(thread, ARM64_VEC_SME);
191}
192
193static inline unsigned int thread_get_cur_vl(struct thread_struct *thread)
194{
195 if (system_supports_sme() && (thread->svcr & SVCR_SM_MASK))
196 return thread_get_sme_vl(thread);
197 else
198 return thread_get_sve_vl(thread);
199}
200
201unsigned int task_get_vl(const struct task_struct *task, enum vec_type type);
202void task_set_vl(struct task_struct *task, enum vec_type type,
203 unsigned long vl);
204void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
205 unsigned long vl);
206unsigned int task_get_vl_onexec(const struct task_struct *task,
207 enum vec_type type);
208
209static inline unsigned int task_get_sve_vl(const struct task_struct *task)
210{
211 return task_get_vl(task, ARM64_VEC_SVE);
212}
213
214static inline unsigned int task_get_sme_vl(const struct task_struct *task)
215{
216 return task_get_vl(task, ARM64_VEC_SME);
217}
218
219static inline void task_set_sve_vl(struct task_struct *task, unsigned long vl)
220{
221 task_set_vl(task, ARM64_VEC_SVE, vl);
222}
223
224static inline unsigned int task_get_sve_vl_onexec(const struct task_struct *task)
225{
226 return task_get_vl_onexec(task, ARM64_VEC_SVE);
227}
228
229static inline void task_set_sve_vl_onexec(struct task_struct *task,
230 unsigned long vl)
231{
232 task_set_vl_onexec(task, ARM64_VEC_SVE, vl);
233}
234
235#define SCTLR_USER_MASK \
236 (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | SCTLR_ELx_ENDA | SCTLR_ELx_ENDB | \
237 SCTLR_EL1_TCF0_MASK)
238
239static inline void arch_thread_struct_whitelist(unsigned long *offset,
240 unsigned long *size)
241{
242 /* Verify that there is no padding among the whitelisted fields: */
243 BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
244 sizeof_field(struct thread_struct, uw.tp_value) +
245 sizeof_field(struct thread_struct, uw.tp2_value) +
246 sizeof_field(struct thread_struct, uw.fpsimd_state));
247
248 *offset = offsetof(struct thread_struct, uw);
249 *size = sizeof_field(struct thread_struct, uw);
250}
251
252#ifdef CONFIG_COMPAT
253#define task_user_tls(t) \
254({ \
255 unsigned long *__tls; \
256 if (is_compat_thread(task_thread_info(t))) \
257 __tls = &(t)->thread.uw.tp2_value; \
258 else \
259 __tls = &(t)->thread.uw.tp_value; \
260 __tls; \
261 })
262#else
263#define task_user_tls(t) (&(t)->thread.uw.tp_value)
264#endif
265
266/* Sync TPIDR_EL0 back to thread_struct for current */
267void tls_preserve_current_state(void);
268
269#define INIT_THREAD { \
270 .fpsimd_cpu = NR_CPUS, \
271}
272
273static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
274{
275 s32 previous_syscall = regs->syscallno;
276 memset(regs, 0, sizeof(*regs));
277 regs->syscallno = previous_syscall;
278 regs->pc = pc;
279
280 if (system_uses_irq_prio_masking())
281 regs->pmr_save = GIC_PRIO_IRQON;
282}
283
284static inline void start_thread(struct pt_regs *regs, unsigned long pc,
285 unsigned long sp)
286{
287 start_thread_common(regs, pc);
288 regs->pstate = PSR_MODE_EL0t;
289 spectre_v4_enable_task_mitigation(current);
290 regs->sp = sp;
291}
292
293#ifdef CONFIG_COMPAT
294static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
295 unsigned long sp)
296{
297 start_thread_common(regs, pc);
298 regs->pstate = PSR_AA32_MODE_USR;
299 if (pc & 1)
300 regs->pstate |= PSR_AA32_T_BIT;
301
302#ifdef __AARCH64EB__
303 regs->pstate |= PSR_AA32_E_BIT;
304#endif
305
306 spectre_v4_enable_task_mitigation(current);
307 regs->compat_sp = sp;
308}
309#endif
310
311static inline bool is_ttbr0_addr(unsigned long addr)
312{
313 /* entry assembly clears tags for TTBR0 addrs */
314 return addr < TASK_SIZE;
315}
316
317static inline bool is_ttbr1_addr(unsigned long addr)
318{
319 /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
320 return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
321}
322
323/* Forward declaration, a strange C thing */
324struct task_struct;
325
326unsigned long __get_wchan(struct task_struct *p);
327
328void update_sctlr_el1(u64 sctlr);
329
330/* Thread switching */
331extern struct task_struct *cpu_switch_to(struct task_struct *prev,
332 struct task_struct *next);
333
334#define task_pt_regs(p) \
335 ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
336
337#define KSTK_EIP(tsk) ((unsigned long)task_pt_regs(tsk)->pc)
338#define KSTK_ESP(tsk) user_stack_pointer(task_pt_regs(tsk))
339
340/*
341 * Prefetching support
342 */
343#define ARCH_HAS_PREFETCH
344static inline void prefetch(const void *ptr)
345{
346 asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
347}
348
349#define ARCH_HAS_PREFETCHW
350static inline void prefetchw(const void *ptr)
351{
352 asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
353}
354
355#define ARCH_HAS_SPINLOCK_PREFETCH
356static inline void spin_lock_prefetch(const void *ptr)
357{
358 asm volatile(ARM64_LSE_ATOMIC_INSN(
359 "prfm pstl1strm, %a0",
360 "nop") : : "p" (ptr));
361}
362
363extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
364extern void __init minsigstksz_setup(void);
365
366/*
367 * Not at the top of the file due to a direct #include cycle between
368 * <asm/fpsimd.h> and <asm/processor.h>. Deferring this #include
369 * ensures that contents of processor.h are visible to fpsimd.h even if
370 * processor.h is included first.
371 *
372 * These prctl helpers are the only things in this file that require
373 * fpsimd.h. The core code expects them to be in this header.
374 */
375#include <asm/fpsimd.h>
376
377/* Userspace interface for PR_S[MV]E_{SET,GET}_VL prctl()s: */
378#define SVE_SET_VL(arg) sve_set_current_vl(arg)
379#define SVE_GET_VL() sve_get_current_vl()
380#define SME_SET_VL(arg) sme_set_current_vl(arg)
381#define SME_GET_VL() sme_get_current_vl()
382
383/* PR_PAC_RESET_KEYS prctl */
384#define PAC_RESET_KEYS(tsk, arg) ptrauth_prctl_reset_keys(tsk, arg)
385
386/* PR_PAC_{SET,GET}_ENABLED_KEYS prctl */
387#define PAC_SET_ENABLED_KEYS(tsk, keys, enabled) \
388 ptrauth_set_enabled_keys(tsk, keys, enabled)
389#define PAC_GET_ENABLED_KEYS(tsk) ptrauth_get_enabled_keys(tsk)
390
391#ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
392/* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
393long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
394long get_tagged_addr_ctrl(struct task_struct *task);
395#define SET_TAGGED_ADDR_CTRL(arg) set_tagged_addr_ctrl(current, arg)
396#define GET_TAGGED_ADDR_CTRL() get_tagged_addr_ctrl(current)
397#endif
398
399/*
400 * For CONFIG_GCC_PLUGIN_STACKLEAK
401 *
402 * These need to be macros because otherwise we get stuck in a nightmare
403 * of header definitions for the use of task_stack_page.
404 */
405
406/*
407 * The top of the current task's task stack
408 */
409#define current_top_of_stack() ((unsigned long)current->stack + THREAD_SIZE)
410#define on_thread_stack() (on_task_stack(current, current_stack_pointer, 1))
411
412#endif /* __ASSEMBLY__ */
413#endif /* __ASM_PROCESSOR_H */