xref: /openbmc/linux/arch/arm64/include/asm/processor.h (revision 48ca54e3)
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 struct 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 
141 struct 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 
177 static inline unsigned int thread_get_vl(struct thread_struct *thread,
178 					 enum vec_type type)
179 {
180 	return thread->vl[type];
181 }
182 
183 static inline unsigned int thread_get_sve_vl(struct thread_struct *thread)
184 {
185 	return thread_get_vl(thread, ARM64_VEC_SVE);
186 }
187 
188 static inline unsigned int thread_get_sme_vl(struct thread_struct *thread)
189 {
190 	return thread_get_vl(thread, ARM64_VEC_SME);
191 }
192 
193 static 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 
201 unsigned int task_get_vl(const struct task_struct *task, enum vec_type type);
202 void task_set_vl(struct task_struct *task, enum vec_type type,
203 		 unsigned long vl);
204 void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
205 			unsigned long vl);
206 unsigned int task_get_vl_onexec(const struct task_struct *task,
207 				enum vec_type type);
208 
209 static inline unsigned int task_get_sve_vl(const struct task_struct *task)
210 {
211 	return task_get_vl(task, ARM64_VEC_SVE);
212 }
213 
214 static inline unsigned int task_get_sme_vl(const struct task_struct *task)
215 {
216 	return task_get_vl(task, ARM64_VEC_SME);
217 }
218 
219 static 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 
224 static 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 
229 static 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 
239 static 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 */
267 void tls_preserve_current_state(void);
268 
269 #define INIT_THREAD {				\
270 	.fpsimd_cpu = NR_CPUS,			\
271 }
272 
273 static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
274 {
275 	memset(regs, 0, sizeof(*regs));
276 	forget_syscall(regs);
277 	regs->pc = pc;
278 
279 	if (system_uses_irq_prio_masking())
280 		regs->pmr_save = GIC_PRIO_IRQON;
281 }
282 
283 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
284 				unsigned long sp)
285 {
286 	start_thread_common(regs, pc);
287 	regs->pstate = PSR_MODE_EL0t;
288 	spectre_v4_enable_task_mitigation(current);
289 	regs->sp = sp;
290 }
291 
292 #ifdef CONFIG_COMPAT
293 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
294 				       unsigned long sp)
295 {
296 	start_thread_common(regs, pc);
297 	regs->pstate = PSR_AA32_MODE_USR;
298 	if (pc & 1)
299 		regs->pstate |= PSR_AA32_T_BIT;
300 
301 #ifdef __AARCH64EB__
302 	regs->pstate |= PSR_AA32_E_BIT;
303 #endif
304 
305 	spectre_v4_enable_task_mitigation(current);
306 	regs->compat_sp = sp;
307 }
308 #endif
309 
310 static inline bool is_ttbr0_addr(unsigned long addr)
311 {
312 	/* entry assembly clears tags for TTBR0 addrs */
313 	return addr < TASK_SIZE;
314 }
315 
316 static inline bool is_ttbr1_addr(unsigned long addr)
317 {
318 	/* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
319 	return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
320 }
321 
322 /* Forward declaration, a strange C thing */
323 struct task_struct;
324 
325 /* Free all resources held by a thread. */
326 extern void release_thread(struct task_struct *);
327 
328 unsigned long __get_wchan(struct task_struct *p);
329 
330 void update_sctlr_el1(u64 sctlr);
331 
332 /* Thread switching */
333 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
334 					 struct task_struct *next);
335 
336 #define task_pt_regs(p) \
337 	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
338 
339 #define KSTK_EIP(tsk)	((unsigned long)task_pt_regs(tsk)->pc)
340 #define KSTK_ESP(tsk)	user_stack_pointer(task_pt_regs(tsk))
341 
342 /*
343  * Prefetching support
344  */
345 #define ARCH_HAS_PREFETCH
346 static inline void prefetch(const void *ptr)
347 {
348 	asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
349 }
350 
351 #define ARCH_HAS_PREFETCHW
352 static inline void prefetchw(const void *ptr)
353 {
354 	asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
355 }
356 
357 #define ARCH_HAS_SPINLOCK_PREFETCH
358 static inline void spin_lock_prefetch(const void *ptr)
359 {
360 	asm volatile(ARM64_LSE_ATOMIC_INSN(
361 		     "prfm pstl1strm, %a0",
362 		     "nop") : : "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 /*
402  * For CONFIG_GCC_PLUGIN_STACKLEAK
403  *
404  * These need to be macros because otherwise we get stuck in a nightmare
405  * of header definitions for the use of task_stack_page.
406  */
407 
408 /*
409  * The top of the current task's task stack
410  */
411 #define current_top_of_stack()	((unsigned long)current->stack + THREAD_SIZE)
412 #define on_thread_stack()	(on_task_stack(current, current_stack_pointer, 1, NULL))
413 
414 #endif /* __ASSEMBLY__ */
415 #endif /* __ASM_PROCESSOR_H */
416