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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#define SHADOW_OVERFLOW_STACK_SIZE (1024)
32
33#define IRQ_STACK_SIZE THREAD_SIZE
34
35#ifndef __ASSEMBLY__
36
37#include <asm/processor.h>
38#include <asm/csr.h>
39
40/*
41 * low level task data that entry.S needs immediate access to
42 * - this struct should fit entirely inside of one cache line
43 * - if the members of this struct changes, the assembly constants
44 * in asm-offsets.c must be updated accordingly
45 * - thread_info is included in task_struct at an offset of 0. This means that
46 * tp points to both thread_info and task_struct.
47 */
48struct thread_info {
49 unsigned long flags; /* low level flags */
50 int preempt_count; /* 0=>preemptible, <0=>BUG */
51 /*
52 * These stack pointers are overwritten on every system call or
53 * exception. SP is also saved to the stack it can be recovered when
54 * overwritten.
55 */
56 long kernel_sp; /* Kernel stack pointer */
57 long user_sp; /* User stack pointer */
58 int cpu;
59 unsigned long syscall_work; /* SYSCALL_WORK_ flags */
60#ifdef CONFIG_SHADOW_CALL_STACK
61 void *scs_base;
62 void *scs_sp;
63#endif
64};
65
66#ifdef CONFIG_SHADOW_CALL_STACK
67#define INIT_SCS \
68 .scs_base = init_shadow_call_stack, \
69 .scs_sp = init_shadow_call_stack,
70#else
71#define INIT_SCS
72#endif
73
74/*
75 * macros/functions for gaining access to the thread information structure
76 *
77 * preempt_count needs to be 1 initially, until the scheduler is functional.
78 */
79#define INIT_THREAD_INFO(tsk) \
80{ \
81 .flags = 0, \
82 .preempt_count = INIT_PREEMPT_COUNT, \
83 INIT_SCS \
84}
85
86void arch_release_task_struct(struct task_struct *tsk);
87int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
88
89#endif /* !__ASSEMBLY__ */
90
91/*
92 * thread information flags
93 * - these are process state flags that various assembly files may need to
94 * access
95 * - pending work-to-be-done flags are in lowest half-word
96 * - other flags in upper half-word(s)
97 */
98#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
99#define TIF_SIGPENDING 2 /* signal pending */
100#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
101#define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */
102#define TIF_MEMDIE 5 /* is terminating due to OOM killer */
103#define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */
104#define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */
105#define TIF_32BIT 11 /* compat-mode 32bit process */
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
113#define _TIF_WORK_MASK \
114 (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \
115 _TIF_NOTIFY_SIGNAL | _TIF_UPROBE)
116
117#endif /* _ASM_RISCV_THREAD_INFO_H */