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 #ifdef CONFIG_KASAN 15 #define KASAN_STACK_ORDER 1 16 #else 17 #define KASAN_STACK_ORDER 0 18 #endif 19 20 /* thread information allocation */ 21 #ifdef CONFIG_64BIT 22 #define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER) 23 #else 24 #define THREAD_SIZE_ORDER (1 + KASAN_STACK_ORDER) 25 #endif 26 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) 27 28 /* 29 * By aligning VMAP'd stacks to 2 * THREAD_SIZE, we can detect overflow by 30 * checking sp & (1 << THREAD_SHIFT), which we can do cheaply in the entry 31 * assembly. 32 */ 33 #ifdef CONFIG_VMAP_STACK 34 #define THREAD_ALIGN (2 * THREAD_SIZE) 35 #else 36 #define THREAD_ALIGN THREAD_SIZE 37 #endif 38 39 #define THREAD_SHIFT (PAGE_SHIFT + THREAD_SIZE_ORDER) 40 #define OVERFLOW_STACK_SIZE SZ_4K 41 #define SHADOW_OVERFLOW_STACK_SIZE (1024) 42 43 #ifndef __ASSEMBLY__ 44 45 extern long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE / sizeof(long)]; 46 extern unsigned long spin_shadow_stack; 47 48 #include <asm/processor.h> 49 #include <asm/csr.h> 50 51 /* 52 * low level task data that entry.S needs immediate access to 53 * - this struct should fit entirely inside of one cache line 54 * - if the members of this struct changes, the assembly constants 55 * in asm-offsets.c must be updated accordingly 56 * - thread_info is included in task_struct at an offset of 0. This means that 57 * tp points to both thread_info and task_struct. 58 */ 59 struct thread_info { 60 unsigned long flags; /* low level flags */ 61 int preempt_count; /* 0=>preemptible, <0=>BUG */ 62 /* 63 * These stack pointers are overwritten on every system call or 64 * exception. SP is also saved to the stack it can be recovered when 65 * overwritten. 66 */ 67 long kernel_sp; /* Kernel stack pointer */ 68 long user_sp; /* User stack pointer */ 69 int cpu; 70 unsigned long syscall_work; /* SYSCALL_WORK_ flags */ 71 }; 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 } 83 84 #endif /* !__ASSEMBLY__ */ 85 86 /* 87 * thread information flags 88 * - these are process state flags that various assembly files may need to 89 * access 90 * - pending work-to-be-done flags are in lowest half-word 91 * - other flags in upper half-word(s) 92 */ 93 #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ 94 #define TIF_SIGPENDING 2 /* signal pending */ 95 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ 96 #define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */ 97 #define TIF_MEMDIE 5 /* is terminating due to OOM killer */ 98 #define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */ 99 #define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */ 100 #define TIF_32BIT 11 /* compat-mode 32bit process */ 101 102 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) 103 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 104 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 105 #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) 106 #define _TIF_UPROBE (1 << TIF_UPROBE) 107 108 #define _TIF_WORK_MASK \ 109 (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \ 110 _TIF_NOTIFY_SIGNAL | _TIF_UPROBE) 111 112 #endif /* _ASM_RISCV_THREAD_INFO_H */ 113