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 extern long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE / sizeof(long)]; 38 extern unsigned long spin_shadow_stack; 39 40 #include <asm/processor.h> 41 #include <asm/csr.h> 42 43 /* 44 * low level task data that entry.S needs immediate access to 45 * - this struct should fit entirely inside of one cache line 46 * - if the members of this struct changes, the assembly constants 47 * in asm-offsets.c must be updated accordingly 48 * - thread_info is included in task_struct at an offset of 0. This means that 49 * tp points to both thread_info and task_struct. 50 */ 51 struct thread_info { 52 unsigned long flags; /* low level flags */ 53 int preempt_count; /* 0=>preemptible, <0=>BUG */ 54 /* 55 * These stack pointers are overwritten on every system call or 56 * exception. SP is also saved to the stack it can be recovered when 57 * overwritten. 58 */ 59 long kernel_sp; /* Kernel stack pointer */ 60 long user_sp; /* User stack pointer */ 61 int cpu; 62 unsigned long syscall_work; /* SYSCALL_WORK_ flags */ 63 }; 64 65 /* 66 * macros/functions for gaining access to the thread information structure 67 * 68 * preempt_count needs to be 1 initially, until the scheduler is functional. 69 */ 70 #define INIT_THREAD_INFO(tsk) \ 71 { \ 72 .flags = 0, \ 73 .preempt_count = INIT_PREEMPT_COUNT, \ 74 } 75 76 void arch_release_task_struct(struct task_struct *tsk); 77 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 78 79 #endif /* !__ASSEMBLY__ */ 80 81 /* 82 * thread information flags 83 * - these are process state flags that various assembly files may need to 84 * access 85 * - pending work-to-be-done flags are in lowest half-word 86 * - other flags in upper half-word(s) 87 */ 88 #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ 89 #define TIF_SIGPENDING 2 /* signal pending */ 90 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ 91 #define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */ 92 #define TIF_MEMDIE 5 /* is terminating due to OOM killer */ 93 #define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */ 94 #define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */ 95 #define TIF_32BIT 11 /* compat-mode 32bit process */ 96 97 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) 98 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 99 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 100 #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) 101 #define _TIF_UPROBE (1 << TIF_UPROBE) 102 103 #define _TIF_WORK_MASK \ 104 (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \ 105 _TIF_NOTIFY_SIGNAL | _TIF_UPROBE) 106 107 #endif /* _ASM_RISCV_THREAD_INFO_H */ 108