xref: /linux/arch/arm64/include/asm/processor.h (revision b8e85e6f3a09fc56b0ff574887798962ef8a8f80)
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 
103 extern phys_addr_t arm64_dma_phys_limit;
104 #define ARCH_LOW_ADDRESS_LIMIT	(arm64_dma_phys_limit - 1)
105 
106 struct 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 
119 enum vec_type {
120 	ARM64_VEC_SVE = 0,
121 	ARM64_VEC_SME,
122 	ARM64_VEC_MAX,
123 };
124 
125 enum fp_type {
126 	FP_STATE_CURRENT,	/* Save based on current task state. */
127 	FP_STATE_FPSIMD,
128 	FP_STATE_SVE,
129 };
130 
131 struct cpu_context {
132 	unsigned long x19;
133 	unsigned long x20;
134 	unsigned long x21;
135 	unsigned long x22;
136 	unsigned long x23;
137 	unsigned long x24;
138 	unsigned long x25;
139 	unsigned long x26;
140 	unsigned long x27;
141 	unsigned long x28;
142 	unsigned long fp;
143 	unsigned long sp;
144 	unsigned long pc;
145 };
146 
147 struct thread_struct {
148 	struct cpu_context	cpu_context;	/* cpu context */
149 
150 	/*
151 	 * Whitelisted fields for hardened usercopy:
152 	 * Maintainers must ensure manually that this contains no
153 	 * implicit padding.
154 	 */
155 	struct {
156 		unsigned long	tp_value;	/* TLS register */
157 		unsigned long	tp2_value;
158 		struct user_fpsimd_state fpsimd_state;
159 	} uw;
160 
161 	enum fp_type		fp_type;	/* registers FPSIMD or SVE? */
162 	unsigned int		fpsimd_cpu;
163 	void			*sve_state;	/* SVE registers, if any */
164 	void			*sme_state;	/* ZA and ZT state, if any */
165 	unsigned int		vl[ARM64_VEC_MAX];	/* vector length */
166 	unsigned int		vl_onexec[ARM64_VEC_MAX]; /* vl after next exec */
167 	unsigned long		fault_address;	/* fault info */
168 	unsigned long		fault_code;	/* ESR_EL1 value */
169 	struct debug_info	debug;		/* debugging */
170 
171 	struct user_fpsimd_state	kernel_fpsimd_state;
172 	unsigned int			kernel_fpsimd_cpu;
173 #ifdef CONFIG_ARM64_PTR_AUTH
174 	struct ptrauth_keys_user	keys_user;
175 #ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
176 	struct ptrauth_keys_kernel	keys_kernel;
177 #endif
178 #endif
179 #ifdef CONFIG_ARM64_MTE
180 	u64			mte_ctrl;
181 #endif
182 	u64			sctlr_user;
183 	u64			svcr;
184 	u64			tpidr2_el0;
185 };
186 
187 static inline unsigned int thread_get_vl(struct thread_struct *thread,
188 					 enum vec_type type)
189 {
190 	return thread->vl[type];
191 }
192 
193 static inline unsigned int thread_get_sve_vl(struct thread_struct *thread)
194 {
195 	return thread_get_vl(thread, ARM64_VEC_SVE);
196 }
197 
198 static inline unsigned int thread_get_sme_vl(struct thread_struct *thread)
199 {
200 	return thread_get_vl(thread, ARM64_VEC_SME);
201 }
202 
203 static inline unsigned int thread_get_cur_vl(struct thread_struct *thread)
204 {
205 	if (system_supports_sme() && (thread->svcr & SVCR_SM_MASK))
206 		return thread_get_sme_vl(thread);
207 	else
208 		return thread_get_sve_vl(thread);
209 }
210 
211 unsigned int task_get_vl(const struct task_struct *task, enum vec_type type);
212 void task_set_vl(struct task_struct *task, enum vec_type type,
213 		 unsigned long vl);
214 void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
215 			unsigned long vl);
216 unsigned int task_get_vl_onexec(const struct task_struct *task,
217 				enum vec_type type);
218 
219 static inline unsigned int task_get_sve_vl(const struct task_struct *task)
220 {
221 	return task_get_vl(task, ARM64_VEC_SVE);
222 }
223 
224 static inline unsigned int task_get_sme_vl(const struct task_struct *task)
225 {
226 	return task_get_vl(task, ARM64_VEC_SME);
227 }
228 
229 static inline void task_set_sve_vl(struct task_struct *task, unsigned long vl)
230 {
231 	task_set_vl(task, ARM64_VEC_SVE, vl);
232 }
233 
234 static inline unsigned int task_get_sve_vl_onexec(const struct task_struct *task)
235 {
236 	return task_get_vl_onexec(task, ARM64_VEC_SVE);
237 }
238 
239 static inline void task_set_sve_vl_onexec(struct task_struct *task,
240 					  unsigned long vl)
241 {
242 	task_set_vl_onexec(task, ARM64_VEC_SVE, vl);
243 }
244 
245 #define SCTLR_USER_MASK                                                        \
246 	(SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | SCTLR_ELx_ENDA | SCTLR_ELx_ENDB |   \
247 	 SCTLR_EL1_TCF0_MASK)
248 
249 static inline void arch_thread_struct_whitelist(unsigned long *offset,
250 						unsigned long *size)
251 {
252 	/* Verify that there is no padding among the whitelisted fields: */
253 	BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
254 		     sizeof_field(struct thread_struct, uw.tp_value) +
255 		     sizeof_field(struct thread_struct, uw.tp2_value) +
256 		     sizeof_field(struct thread_struct, uw.fpsimd_state));
257 
258 	*offset = offsetof(struct thread_struct, uw);
259 	*size = sizeof_field(struct thread_struct, uw);
260 }
261 
262 #ifdef CONFIG_COMPAT
263 #define task_user_tls(t)						\
264 ({									\
265 	unsigned long *__tls;						\
266 	if (is_compat_thread(task_thread_info(t)))			\
267 		__tls = &(t)->thread.uw.tp2_value;			\
268 	else								\
269 		__tls = &(t)->thread.uw.tp_value;			\
270 	__tls;								\
271  })
272 #else
273 #define task_user_tls(t)	(&(t)->thread.uw.tp_value)
274 #endif
275 
276 /* Sync TPIDR_EL0 back to thread_struct for current */
277 void tls_preserve_current_state(void);
278 
279 #define INIT_THREAD {				\
280 	.fpsimd_cpu = NR_CPUS,			\
281 }
282 
283 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
284 {
285 	s32 previous_syscall = regs->syscallno;
286 	memset(regs, 0, sizeof(*regs));
287 	regs->syscallno = previous_syscall;
288 	regs->pc = pc;
289 
290 	if (system_uses_irq_prio_masking())
291 		regs->pmr_save = GIC_PRIO_IRQON;
292 }
293 
294 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
295 				unsigned long sp)
296 {
297 	start_thread_common(regs, pc);
298 	regs->pstate = PSR_MODE_EL0t;
299 	spectre_v4_enable_task_mitigation(current);
300 	regs->sp = sp;
301 }
302 
303 #ifdef CONFIG_COMPAT
304 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
305 				       unsigned long sp)
306 {
307 	start_thread_common(regs, pc);
308 	regs->pstate = PSR_AA32_MODE_USR;
309 	if (pc & 1)
310 		regs->pstate |= PSR_AA32_T_BIT;
311 
312 #ifdef __AARCH64EB__
313 	regs->pstate |= PSR_AA32_E_BIT;
314 #endif
315 
316 	spectre_v4_enable_task_mitigation(current);
317 	regs->compat_sp = sp;
318 }
319 #endif
320 
321 static __always_inline bool is_ttbr0_addr(unsigned long addr)
322 {
323 	/* entry assembly clears tags for TTBR0 addrs */
324 	return addr < TASK_SIZE;
325 }
326 
327 static __always_inline bool is_ttbr1_addr(unsigned long addr)
328 {
329 	/* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
330 	return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
331 }
332 
333 /* Forward declaration, a strange C thing */
334 struct task_struct;
335 
336 unsigned long __get_wchan(struct task_struct *p);
337 
338 void update_sctlr_el1(u64 sctlr);
339 
340 /* Thread switching */
341 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
342 					 struct task_struct *next);
343 
344 #define task_pt_regs(p) \
345 	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
346 
347 #define KSTK_EIP(tsk)	((unsigned long)task_pt_regs(tsk)->pc)
348 #define KSTK_ESP(tsk)	user_stack_pointer(task_pt_regs(tsk))
349 
350 /*
351  * Prefetching support
352  */
353 #define ARCH_HAS_PREFETCH
354 static inline void prefetch(const void *ptr)
355 {
356 	asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
357 }
358 
359 #define ARCH_HAS_PREFETCHW
360 static inline void prefetchw(const void *ptr)
361 {
362 	asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
363 }
364 
365 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
366 extern void __init minsigstksz_setup(void);
367 
368 /*
369  * Not at the top of the file due to a direct #include cycle between
370  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
371  * ensures that contents of processor.h are visible to fpsimd.h even if
372  * processor.h is included first.
373  *
374  * These prctl helpers are the only things in this file that require
375  * fpsimd.h.  The core code expects them to be in this header.
376  */
377 #include <asm/fpsimd.h>
378 
379 /* Userspace interface for PR_S[MV]E_{SET,GET}_VL prctl()s: */
380 #define SVE_SET_VL(arg)	sve_set_current_vl(arg)
381 #define SVE_GET_VL()	sve_get_current_vl()
382 #define SME_SET_VL(arg)	sme_set_current_vl(arg)
383 #define SME_GET_VL()	sme_get_current_vl()
384 
385 /* PR_PAC_RESET_KEYS prctl */
386 #define PAC_RESET_KEYS(tsk, arg)	ptrauth_prctl_reset_keys(tsk, arg)
387 
388 /* PR_PAC_{SET,GET}_ENABLED_KEYS prctl */
389 #define PAC_SET_ENABLED_KEYS(tsk, keys, enabled)				\
390 	ptrauth_set_enabled_keys(tsk, keys, enabled)
391 #define PAC_GET_ENABLED_KEYS(tsk) ptrauth_get_enabled_keys(tsk)
392 
393 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
394 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
395 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
396 long get_tagged_addr_ctrl(struct task_struct *task);
397 #define SET_TAGGED_ADDR_CTRL(arg)	set_tagged_addr_ctrl(current, arg)
398 #define GET_TAGGED_ADDR_CTRL()		get_tagged_addr_ctrl(current)
399 #endif
400 
401 #endif /* __ASSEMBLY__ */
402 #endif /* __ASM_PROCESSOR_H */
403