xref: /openbmc/linux/arch/arm/include/asm/processor.h (revision 5b4fc395)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  *  arch/arm/include/asm/processor.h
4  *
5  *  Copyright (C) 1995-1999 Russell King
6  */
7 
8 #ifndef __ASM_ARM_PROCESSOR_H
9 #define __ASM_ARM_PROCESSOR_H
10 
11 #ifdef __KERNEL__
12 
13 #include <asm/hw_breakpoint.h>
14 #include <asm/ptrace.h>
15 #include <asm/types.h>
16 #include <asm/unified.h>
17 #include <asm/vdso/processor.h>
18 
19 #ifdef __KERNEL__
20 #define STACK_TOP	((current->personality & ADDR_LIMIT_32BIT) ? \
21 			 TASK_SIZE : TASK_SIZE_26)
22 #define STACK_TOP_MAX	TASK_SIZE
23 #endif
24 
25 struct debug_info {
26 #ifdef CONFIG_HAVE_HW_BREAKPOINT
27 	struct perf_event	*hbp[ARM_MAX_HBP_SLOTS];
28 #endif
29 };
30 
31 struct thread_struct {
32 							/* fault info	  */
33 	unsigned long		address;
34 	unsigned long		trap_no;
35 	unsigned long		error_code;
36 							/* debugging	  */
37 	struct debug_info	debug;
38 };
39 
40 /*
41  * Everything usercopied to/from thread_struct is statically-sized, so
42  * no hardened usercopy whitelist is needed.
43  */
44 static inline void arch_thread_struct_whitelist(unsigned long *offset,
45 						unsigned long *size)
46 {
47 	*offset = *size = 0;
48 }
49 
50 #define INIT_THREAD  {	}
51 
52 #define start_thread(regs,pc,sp)					\
53 ({									\
54 	unsigned long r7, r8, r9;					\
55 									\
56 	if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC)) {			\
57 		r7 = regs->ARM_r7;					\
58 		r8 = regs->ARM_r8;					\
59 		r9 = regs->ARM_r9;					\
60 	}								\
61 	memset(regs->uregs, 0, sizeof(regs->uregs));			\
62 	if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC) &&			\
63 	    current->personality & FDPIC_FUNCPTRS) {			\
64 		regs->ARM_r7 = r7;					\
65 		regs->ARM_r8 = r8;					\
66 		regs->ARM_r9 = r9;					\
67 		regs->ARM_r10 = current->mm->start_data;		\
68 	} else if (!IS_ENABLED(CONFIG_MMU))				\
69 		regs->ARM_r10 = current->mm->start_data;		\
70 	if (current->personality & ADDR_LIMIT_32BIT)			\
71 		regs->ARM_cpsr = USR_MODE;				\
72 	else								\
73 		regs->ARM_cpsr = USR26_MODE;				\
74 	if (elf_hwcap & HWCAP_THUMB && pc & 1)				\
75 		regs->ARM_cpsr |= PSR_T_BIT;				\
76 	regs->ARM_cpsr |= PSR_ENDSTATE;					\
77 	regs->ARM_pc = pc & ~1;		/* pc */			\
78 	regs->ARM_sp = sp;		/* sp */			\
79 })
80 
81 /* Forward declaration, a strange C thing */
82 struct task_struct;
83 
84 /* Free all resources held by a thread. */
85 extern void release_thread(struct task_struct *);
86 
87 unsigned long __get_wchan(struct task_struct *p);
88 
89 #define task_pt_regs(p) \
90 	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
91 
92 #define KSTK_EIP(tsk)	task_pt_regs(tsk)->ARM_pc
93 #define KSTK_ESP(tsk)	task_pt_regs(tsk)->ARM_sp
94 
95 #ifdef CONFIG_SMP
96 #define __ALT_SMP_ASM(smp, up)						\
97 	"9998:	" smp "\n"						\
98 	"	.pushsection \".alt.smp.init\", \"a\"\n"		\
99 	"	.align	2\n"						\
100 	"	.long	9998b - .\n"					\
101 	"	" up "\n"						\
102 	"	.popsection\n"
103 #else
104 #define __ALT_SMP_ASM(smp, up)	up
105 #endif
106 
107 /*
108  * Prefetching support - only ARMv5.
109  */
110 #if __LINUX_ARM_ARCH__ >= 5
111 
112 #define ARCH_HAS_PREFETCH
113 static inline void prefetch(const void *ptr)
114 {
115 	__asm__ __volatile__(
116 		"pld\t%a0"
117 		:: "p" (ptr));
118 }
119 
120 #if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
121 #define ARCH_HAS_PREFETCHW
122 static inline void prefetchw(const void *ptr)
123 {
124 	__asm__ __volatile__(
125 		".arch_extension	mp\n"
126 		__ALT_SMP_ASM(
127 			"pldw\t%a0",
128 			"pld\t%a0"
129 		)
130 		:: "p" (ptr));
131 }
132 #endif
133 #endif
134 
135 #endif
136 
137 #endif /* __ASM_ARM_PROCESSOR_H */
138