xref: /openbmc/linux/arch/arm64/include/asm/processor.h (revision 8dd3cdea)
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) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
96 				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_MAX,
122 };
123 
124 struct cpu_context {
125 	unsigned long x19;
126 	unsigned long x20;
127 	unsigned long x21;
128 	unsigned long x22;
129 	unsigned long x23;
130 	unsigned long x24;
131 	unsigned long x25;
132 	unsigned long x26;
133 	unsigned long x27;
134 	unsigned long x28;
135 	unsigned long fp;
136 	unsigned long sp;
137 	unsigned long pc;
138 };
139 
140 struct thread_struct {
141 	struct cpu_context	cpu_context;	/* cpu context */
142 
143 	/*
144 	 * Whitelisted fields for hardened usercopy:
145 	 * Maintainers must ensure manually that this contains no
146 	 * implicit padding.
147 	 */
148 	struct {
149 		unsigned long	tp_value;	/* TLS register */
150 		unsigned long	tp2_value;
151 		struct user_fpsimd_state fpsimd_state;
152 	} uw;
153 
154 	unsigned int		fpsimd_cpu;
155 	void			*sve_state;	/* SVE registers, if any */
156 	unsigned int		vl[ARM64_VEC_MAX];	/* vector length */
157 	unsigned int		vl_onexec[ARM64_VEC_MAX]; /* vl after next exec */
158 	unsigned long		fault_address;	/* fault info */
159 	unsigned long		fault_code;	/* ESR_EL1 value */
160 	struct debug_info	debug;		/* debugging */
161 #ifdef CONFIG_ARM64_PTR_AUTH
162 	struct ptrauth_keys_user	keys_user;
163 #ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
164 	struct ptrauth_keys_kernel	keys_kernel;
165 #endif
166 #endif
167 #ifdef CONFIG_ARM64_MTE
168 	u64			mte_ctrl;
169 #endif
170 	u64			sctlr_user;
171 };
172 
173 static inline unsigned int thread_get_vl(struct thread_struct *thread,
174 					 enum vec_type type)
175 {
176 	return thread->vl[type];
177 }
178 
179 static inline unsigned int thread_get_sve_vl(struct thread_struct *thread)
180 {
181 	return thread_get_vl(thread, ARM64_VEC_SVE);
182 }
183 
184 unsigned int task_get_vl(const struct task_struct *task, enum vec_type type);
185 void task_set_vl(struct task_struct *task, enum vec_type type,
186 		 unsigned long vl);
187 void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
188 			unsigned long vl);
189 unsigned int task_get_vl_onexec(const struct task_struct *task,
190 				enum vec_type type);
191 
192 static inline unsigned int task_get_sve_vl(const struct task_struct *task)
193 {
194 	return task_get_vl(task, ARM64_VEC_SVE);
195 }
196 
197 static inline void task_set_sve_vl(struct task_struct *task, unsigned long vl)
198 {
199 	task_set_vl(task, ARM64_VEC_SVE, vl);
200 }
201 
202 static inline unsigned int task_get_sve_vl_onexec(const struct task_struct *task)
203 {
204 	return task_get_vl_onexec(task, ARM64_VEC_SVE);
205 }
206 
207 static inline void task_set_sve_vl_onexec(struct task_struct *task,
208 					  unsigned long vl)
209 {
210 	task_set_vl_onexec(task, ARM64_VEC_SVE, vl);
211 }
212 
213 #define SCTLR_USER_MASK                                                        \
214 	(SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | SCTLR_ELx_ENDA | SCTLR_ELx_ENDB |   \
215 	 SCTLR_EL1_TCF0_MASK)
216 
217 static inline void arch_thread_struct_whitelist(unsigned long *offset,
218 						unsigned long *size)
219 {
220 	/* Verify that there is no padding among the whitelisted fields: */
221 	BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
222 		     sizeof_field(struct thread_struct, uw.tp_value) +
223 		     sizeof_field(struct thread_struct, uw.tp2_value) +
224 		     sizeof_field(struct thread_struct, uw.fpsimd_state));
225 
226 	*offset = offsetof(struct thread_struct, uw);
227 	*size = sizeof_field(struct thread_struct, uw);
228 }
229 
230 #ifdef CONFIG_COMPAT
231 #define task_user_tls(t)						\
232 ({									\
233 	unsigned long *__tls;						\
234 	if (is_compat_thread(task_thread_info(t)))			\
235 		__tls = &(t)->thread.uw.tp2_value;			\
236 	else								\
237 		__tls = &(t)->thread.uw.tp_value;			\
238 	__tls;								\
239  })
240 #else
241 #define task_user_tls(t)	(&(t)->thread.uw.tp_value)
242 #endif
243 
244 /* Sync TPIDR_EL0 back to thread_struct for current */
245 void tls_preserve_current_state(void);
246 
247 #define INIT_THREAD {				\
248 	.fpsimd_cpu = NR_CPUS,			\
249 }
250 
251 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
252 {
253 	memset(regs, 0, sizeof(*regs));
254 	forget_syscall(regs);
255 	regs->pc = pc;
256 
257 	if (system_uses_irq_prio_masking())
258 		regs->pmr_save = GIC_PRIO_IRQON;
259 }
260 
261 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
262 				unsigned long sp)
263 {
264 	start_thread_common(regs, pc);
265 	regs->pstate = PSR_MODE_EL0t;
266 	spectre_v4_enable_task_mitigation(current);
267 	regs->sp = sp;
268 }
269 
270 #ifdef CONFIG_COMPAT
271 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
272 				       unsigned long sp)
273 {
274 	start_thread_common(regs, pc);
275 	regs->pstate = PSR_AA32_MODE_USR;
276 	if (pc & 1)
277 		regs->pstate |= PSR_AA32_T_BIT;
278 
279 #ifdef __AARCH64EB__
280 	regs->pstate |= PSR_AA32_E_BIT;
281 #endif
282 
283 	spectre_v4_enable_task_mitigation(current);
284 	regs->compat_sp = sp;
285 }
286 #endif
287 
288 static inline bool is_ttbr0_addr(unsigned long addr)
289 {
290 	/* entry assembly clears tags for TTBR0 addrs */
291 	return addr < TASK_SIZE;
292 }
293 
294 static inline bool is_ttbr1_addr(unsigned long addr)
295 {
296 	/* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
297 	return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
298 }
299 
300 /* Forward declaration, a strange C thing */
301 struct task_struct;
302 
303 /* Free all resources held by a thread. */
304 extern void release_thread(struct task_struct *);
305 
306 unsigned long __get_wchan(struct task_struct *p);
307 
308 void update_sctlr_el1(u64 sctlr);
309 
310 /* Thread switching */
311 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
312 					 struct task_struct *next);
313 
314 #define task_pt_regs(p) \
315 	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
316 
317 #define KSTK_EIP(tsk)	((unsigned long)task_pt_regs(tsk)->pc)
318 #define KSTK_ESP(tsk)	user_stack_pointer(task_pt_regs(tsk))
319 
320 /*
321  * Prefetching support
322  */
323 #define ARCH_HAS_PREFETCH
324 static inline void prefetch(const void *ptr)
325 {
326 	asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
327 }
328 
329 #define ARCH_HAS_PREFETCHW
330 static inline void prefetchw(const void *ptr)
331 {
332 	asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
333 }
334 
335 #define ARCH_HAS_SPINLOCK_PREFETCH
336 static inline void spin_lock_prefetch(const void *ptr)
337 {
338 	asm volatile(ARM64_LSE_ATOMIC_INSN(
339 		     "prfm pstl1strm, %a0",
340 		     "nop") : : "p" (ptr));
341 }
342 
343 extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
344 extern void __init minsigstksz_setup(void);
345 
346 /*
347  * Not at the top of the file due to a direct #include cycle between
348  * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
349  * ensures that contents of processor.h are visible to fpsimd.h even if
350  * processor.h is included first.
351  *
352  * These prctl helpers are the only things in this file that require
353  * fpsimd.h.  The core code expects them to be in this header.
354  */
355 #include <asm/fpsimd.h>
356 
357 /* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
358 #define SVE_SET_VL(arg)	sve_set_current_vl(arg)
359 #define SVE_GET_VL()	sve_get_current_vl()
360 
361 /* PR_PAC_RESET_KEYS prctl */
362 #define PAC_RESET_KEYS(tsk, arg)	ptrauth_prctl_reset_keys(tsk, arg)
363 
364 /* PR_PAC_{SET,GET}_ENABLED_KEYS prctl */
365 #define PAC_SET_ENABLED_KEYS(tsk, keys, enabled)				\
366 	ptrauth_set_enabled_keys(tsk, keys, enabled)
367 #define PAC_GET_ENABLED_KEYS(tsk) ptrauth_get_enabled_keys(tsk)
368 
369 #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI
370 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */
371 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg);
372 long get_tagged_addr_ctrl(struct task_struct *task);
373 #define SET_TAGGED_ADDR_CTRL(arg)	set_tagged_addr_ctrl(current, arg)
374 #define GET_TAGGED_ADDR_CTRL()		get_tagged_addr_ctrl(current)
375 #endif
376 
377 /*
378  * For CONFIG_GCC_PLUGIN_STACKLEAK
379  *
380  * These need to be macros because otherwise we get stuck in a nightmare
381  * of header definitions for the use of task_stack_page.
382  */
383 
384 #define current_top_of_stack()								\
385 ({											\
386 	struct stack_info _info;							\
387 	BUG_ON(!on_accessible_stack(current, current_stack_pointer, 1, &_info));	\
388 	_info.high;									\
389 })
390 #define on_thread_stack()	(on_task_stack(current, current_stack_pointer, 1, NULL))
391 
392 #endif /* __ASSEMBLY__ */
393 #endif /* __ASM_PROCESSOR_H */
394