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 */ 53 struct 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 98 void arch_release_task_struct(struct task_struct *tsk); 99 int 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 */ 125