xref: /openbmc/linux/arch/riscv/include/asm/processor.h (revision 2cc39179)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  */
5 
6 #ifndef _ASM_RISCV_PROCESSOR_H
7 #define _ASM_RISCV_PROCESSOR_H
8 
9 #include <linux/const.h>
10 
11 #include <vdso/processor.h>
12 
13 #include <asm/ptrace.h>
14 
15 /*
16  * This decides where the kernel will search for a free chunk of vm
17  * space during mmap's.
18  */
19 #define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE / 3)
20 
21 #define STACK_TOP		TASK_SIZE
22 #ifdef CONFIG_64BIT
23 #define STACK_TOP_MAX		TASK_SIZE_64
24 #else
25 #define STACK_TOP_MAX		TASK_SIZE
26 #endif
27 #define STACK_ALIGN		16
28 
29 #ifndef __ASSEMBLY__
30 
31 struct task_struct;
32 struct pt_regs;
33 
34 /* CPU-specific state of a task */
35 struct thread_struct {
36 	/* Callee-saved registers */
37 	unsigned long ra;
38 	unsigned long sp;	/* Kernel mode stack */
39 	unsigned long s[12];	/* s[0]: frame pointer */
40 	struct __riscv_d_ext_state fstate;
41 	unsigned long bad_cause;
42 };
43 
44 /* Whitelist the fstate from the task_struct for hardened usercopy */
45 static inline void arch_thread_struct_whitelist(unsigned long *offset,
46 						unsigned long *size)
47 {
48 	*offset = offsetof(struct thread_struct, fstate);
49 	*size = sizeof_field(struct thread_struct, fstate);
50 }
51 
52 #define INIT_THREAD {					\
53 	.sp = sizeof(init_stack) + (long)&init_stack,	\
54 }
55 
56 #define task_pt_regs(tsk)						\
57 	((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE		\
58 			    - ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))
59 
60 #define KSTK_EIP(tsk)		(task_pt_regs(tsk)->epc)
61 #define KSTK_ESP(tsk)		(task_pt_regs(tsk)->sp)
62 
63 
64 /* Do necessary setup to start up a newly executed thread. */
65 extern void start_thread(struct pt_regs *regs,
66 			unsigned long pc, unsigned long sp);
67 
68 /* Free all resources held by a thread. */
69 static inline void release_thread(struct task_struct *dead_task)
70 {
71 }
72 
73 extern unsigned long __get_wchan(struct task_struct *p);
74 
75 
76 static inline void wait_for_interrupt(void)
77 {
78 	__asm__ __volatile__ ("wfi");
79 }
80 
81 struct device_node;
82 int riscv_of_processor_hartid(struct device_node *node);
83 int riscv_of_parent_hartid(struct device_node *node);
84 
85 extern void riscv_fill_hwcap(void);
86 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
87 
88 #endif /* __ASSEMBLY__ */
89 
90 #endif /* _ASM_RISCV_PROCESSOR_H */
91