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 <asm/ptrace.h>
12
13 /*
14 * This decides where the kernel will search for a free chunk of vm
15 * space during mmap's.
16 */
17 #define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
18
19 #define STACK_TOP TASK_SIZE
20 #define STACK_TOP_MAX STACK_TOP
21 #define STACK_ALIGN 16
22
23 #ifndef __ASSEMBLY__
24
25 struct task_struct;
26 struct pt_regs;
27
28 /* CPU-specific state of a task */
29 struct thread_struct {
30 /* Callee-saved registers */
31 unsigned long ra;
32 unsigned long sp; /* Kernel mode stack */
33 unsigned long s[12]; /* s[0]: frame pointer */
34 struct __riscv_d_ext_state fstate;
35 };
36
37 #define INIT_THREAD { \
38 .sp = sizeof(init_stack) + (long)&init_stack, \
39 }
40
41 #define task_pt_regs(tsk) \
42 ((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE \
43 - ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))
44
45 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->epc)
46 #define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
47
48
49 /* Do necessary setup to start up a newly executed thread. */
50 extern void start_thread(struct pt_regs *regs,
51 unsigned long pc, unsigned long sp);
52
53 /* Free all resources held by a thread. */
54 static inline void release_thread(struct task_struct *dead_task)
55 {
56 }
57
58 extern unsigned long get_wchan(struct task_struct *p);
59
60
61 static inline void cpu_relax(void)
62 {
63 #ifdef __riscv_muldiv
64 int dummy;
65 /* In lieu of a halt instruction, induce a long-latency stall. */
66 __asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
67 #endif
68 barrier();
69 }
70
71 static inline void wait_for_interrupt(void)
72 {
73 __asm__ __volatile__ ("wfi");
74 }
75
76 struct device_node;
77 int riscv_of_processor_hartid(struct device_node *node);
78
79 extern void riscv_fill_hwcap(void);
80
81 #endif /* __ASSEMBLY__ */
82
83 #endif /* _ASM_RISCV_PROCESSOR_H */
84
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.