Linux kernel mirror (for testing)
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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#include <linux/sizes.h>
14
15/* thread information allocation */
16#ifdef CONFIG_KASAN
17#define KASAN_STACK_ORDER 1
18#else
19#define KASAN_STACK_ORDER 0
20#endif
21#define THREAD_SIZE_ORDER (CONFIG_THREAD_SIZE_ORDER + KASAN_STACK_ORDER)
22#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
23
24/*
25 * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by
26 * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry
27 * assembly.
28 */
29#ifdef CONFIG_VMAP_STACK
30#define THREAD_ALIGN (2 * THREAD_SIZE)
31#else
32#define THREAD_ALIGN THREAD_SIZE
33#endif
34
35#define THREAD_SHIFT (PAGE_SHIFT + THREAD_SIZE_ORDER)
36#define OVERFLOW_STACK_SIZE SZ_4K
37
38#define IRQ_STACK_SIZE THREAD_SIZE
39
40#ifndef __ASSEMBLER__
41
42#include <asm/processor.h>
43#include <asm/csr.h>
44
45/*
46 * low level task data that entry.S needs immediate access to
47 * - this struct should fit entirely inside of one cache line
48 * - if the members of this struct changes, the assembly constants
49 * in asm-offsets.c must be updated accordingly
50 * - thread_info is included in task_struct at an offset of 0. This means that
51 * tp points to both thread_info and task_struct.
52 */
53struct thread_info {
54 unsigned long flags; /* low level flags */
55 int preempt_count; /* 0=>preemptible, <0=>BUG */
56 /*
57 * These stack pointers are overwritten on every system call or
58 * exception. SP is also saved to the stack it can be recovered when
59 * overwritten.
60 */
61 long kernel_sp; /* Kernel stack pointer */
62 long user_sp; /* User stack pointer */
63 int cpu;
64 unsigned long syscall_work; /* SYSCALL_WORK_ flags */
65#ifdef CONFIG_SHADOW_CALL_STACK
66 void *scs_base;
67 void *scs_sp;
68#endif
69#ifdef CONFIG_64BIT
70 /*
71 * Used in handle_exception() to save a0, a1 and a2 before knowing if we
72 * can access the kernel stack.
73 */
74 unsigned long a0, a1, a2;
75#endif
76};
77
78#ifdef CONFIG_SHADOW_CALL_STACK
79#define INIT_SCS \
80 .scs_base = init_shadow_call_stack, \
81 .scs_sp = init_shadow_call_stack,
82#else
83#define INIT_SCS
84#endif
85
86/*
87 * macros/functions for gaining access to the thread information structure
88 *
89 * preempt_count needs to be 1 initially, until the scheduler is functional.
90 */
91#define INIT_THREAD_INFO(tsk) \
92{ \
93 .flags = 0, \
94 .preempt_count = INIT_PREEMPT_COUNT, \
95 INIT_SCS \
96}
97
98void arch_release_task_struct(struct task_struct *tsk);
99int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
100
101#endif /* !__ASSEMBLER__ */
102
103/*
104 * thread information flags
105 * - these are process state flags that various assembly files may need to
106 * access
107 * - pending work-to-be-done flags are in lowest half-word
108 * - other flags in upper half-word(s)
109 */
110
111/*
112 * Tell the generic TIF infrastructure which bits riscv supports
113 */
114#define HAVE_TIF_NEED_RESCHED_LAZY
115#define HAVE_TIF_RESTORE_SIGMASK
116
117#include <asm-generic/thread_info_tif.h>
118
119#define TIF_32BIT 16 /* compat-mode 32bit process */
120#define TIF_RISCV_V_DEFER_RESTORE 17 /* restore Vector before returing to user */
121
122#define _TIF_RISCV_V_DEFER_RESTORE BIT(TIF_RISCV_V_DEFER_RESTORE)
123
124#endif /* _ASM_RISCV_THREAD_INFO_H */