1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
4 * Copyright (C) 2012 Regents of the University of California
5 * Copyright (C) 2017 SiFive
6 */
7
8#ifndef _ASM_RISCV_THREAD_INFO_H
9#define _ASM_RISCV_THREAD_INFO_H
10
11#include <asm/page.h>
12#include <linux/const.h>
13
14/* thread information allocation */
15#define THREAD_SIZE_ORDER	CONFIG_THREAD_SIZE_ORDER
16#define THREAD_SIZE		(PAGE_SIZE << THREAD_SIZE_ORDER)
17
18/*
19 * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
20 * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
21 * assembly.
22 */
23#ifdef CONFIG_VMAP_STACK
24#define THREAD_ALIGN            (2 * THREAD_SIZE)
25#else
26#define THREAD_ALIGN            THREAD_SIZE
27#endif
28
29#define THREAD_SHIFT            (PAGE_SHIFT + THREAD_SIZE_ORDER)
30#define OVERFLOW_STACK_SIZE     SZ_4K
31
32#define IRQ_STACK_SIZE		THREAD_SIZE
33
34#ifndef __ASSEMBLY__
35
36#include <asm/processor.h>
37#include <asm/csr.h>
38
39/*
40 * low level task data that entry.S needs immediate access to
41 * - this struct should fit entirely inside of one cache line
42 * - if the members of this struct changes, the assembly constants
43 *   in asm-offsets.c must be updated accordingly
44 * - thread_info is included in task_struct at an offset of 0.  This means that
45 *   tp points to both thread_info and task_struct.
46 */
47struct thread_info {
48	unsigned long		flags;		/* low level flags */
49	int                     preempt_count;  /* 0=>preemptible, <0=>BUG */
50	/*
51	 * These stack pointers are overwritten on every system call or
52	 * exception.  SP is also saved to the stack it can be recovered when
53	 * overwritten.
54	 */
55	long			kernel_sp;	/* Kernel stack pointer */
56	long			user_sp;	/* User stack pointer */
57	int			cpu;
58	unsigned long		syscall_work;	/* SYSCALL_WORK_ flags */
59#ifdef CONFIG_SHADOW_CALL_STACK
60	void			*scs_base;
61	void			*scs_sp;
62#endif
63};
64
65#ifdef CONFIG_SHADOW_CALL_STACK
66#define INIT_SCS							\
67	.scs_base	= init_shadow_call_stack,			\
68	.scs_sp		= init_shadow_call_stack,
69#else
70#define INIT_SCS
71#endif
72
73/*
74 * macros/functions for gaining access to the thread information structure
75 *
76 * preempt_count needs to be 1 initially, until the scheduler is functional.
77 */
78#define INIT_THREAD_INFO(tsk)			\
79{						\
80	.flags		= 0,			\
81	.preempt_count	= INIT_PREEMPT_COUNT,	\
82	INIT_SCS				\
83}
84
85void arch_release_task_struct(struct task_struct *tsk);
86int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
87
88#endif /* !__ASSEMBLY__ */
89
90/*
91 * thread information flags
92 * - these are process state flags that various assembly files may need to
93 *   access
94 * - pending work-to-be-done flags are in lowest half-word
95 * - other flags in upper half-word(s)
96 */
97#define TIF_NOTIFY_RESUME	1	/* callback before returning to user */
98#define TIF_SIGPENDING		2	/* signal pending */
99#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
100#define TIF_RESTORE_SIGMASK	4	/* restore signal mask in do_signal() */
101#define TIF_MEMDIE		5	/* is terminating due to OOM killer */
102#define TIF_NOTIFY_SIGNAL	9	/* signal notifications exist */
103#define TIF_UPROBE		10	/* uprobe breakpoint or singlestep */
104#define TIF_32BIT		11	/* compat-mode 32bit process */
105#define TIF_RISCV_V_DEFER_RESTORE	12 /* restore Vector before returing to user */
106
107#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
108#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
109#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
110#define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
111#define _TIF_UPROBE		(1 << TIF_UPROBE)
112#define _TIF_RISCV_V_DEFER_RESTORE	(1 << TIF_RISCV_V_DEFER_RESTORE)
113
114#define _TIF_WORK_MASK \
115	(_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \
116	 _TIF_NOTIFY_SIGNAL | _TIF_UPROBE)
117
118#endif /* _ASM_RISCV_THREAD_INFO_H */
119