1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* thread_info.h: Meta low-level thread information 3 * 4 * Copyright (C) 2002 David Howells (dhowells@redhat.com) 5 * - Incorporating suggestions made by Linus Torvalds and Dave Miller 6 * 7 * Meta port by Imagination Technologies 8 */ 9 10 #ifndef _ASM_THREAD_INFO_H 11 #define _ASM_THREAD_INFO_H 12 13 #include <linux/compiler.h> 14 #include <asm/page.h> 15 16 #ifndef __ASSEMBLY__ 17 #include <asm/processor.h> 18 #endif 19 20 /* 21 * low level task data that entry.S needs immediate access to 22 * - this struct should fit entirely inside of one cache line 23 * - this struct shares the supervisor stack pages 24 * - if the contents of this structure are changed, the assembly constants must 25 * also be changed 26 */ 27 #ifndef __ASSEMBLY__ 28 29 /* This must be 8 byte aligned so we can ensure stack alignment. */ 30 struct thread_info { 31 struct task_struct *task; /* main task structure */ 32 unsigned long flags; /* low level flags */ 33 unsigned long status; /* thread-synchronous flags */ 34 u32 cpu; /* current CPU */ 35 int preempt_count; /* 0 => preemptable, <0 => BUG */ 36 37 mm_segment_t addr_limit; /* thread address space */ 38 39 u8 supervisor_stack[0] __aligned(8); 40 }; 41 42 #else /* !__ASSEMBLY__ */ 43 44 #include <generated/asm-offsets.h> 45 46 #endif 47 48 #ifdef CONFIG_4KSTACKS 49 #define THREAD_SHIFT 12 50 #else 51 #define THREAD_SHIFT 13 52 #endif 53 54 #if THREAD_SHIFT >= PAGE_SHIFT 55 #define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT) 56 #else 57 #define THREAD_SIZE_ORDER 0 58 #endif 59 60 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) 61 62 #define STACK_WARN (THREAD_SIZE/8) 63 /* 64 * macros/functions for gaining access to the thread information structure 65 */ 66 #ifndef __ASSEMBLY__ 67 68 #define INIT_THREAD_INFO(tsk) \ 69 { \ 70 .task = &tsk, \ 71 .flags = 0, \ 72 .cpu = 0, \ 73 .preempt_count = INIT_PREEMPT_COUNT, \ 74 .addr_limit = KERNEL_DS, \ 75 } 76 77 #define init_thread_info (init_thread_union.thread_info) 78 #define init_stack (init_thread_union.stack) 79 80 /* how to get the current stack pointer from C */ 81 register unsigned long current_stack_pointer asm("A0StP") __used; 82 83 /* how to get the thread information struct from C */ current_thread_info(void)84static inline struct thread_info *current_thread_info(void) 85 { 86 return (struct thread_info *)(current_stack_pointer & 87 ~(THREAD_SIZE - 1)); 88 } 89 90 #define __HAVE_ARCH_KSTACK_END kstack_end(void * addr)91static inline int kstack_end(void *addr) 92 { 93 return addr == (void *) (((unsigned long) addr & ~(THREAD_SIZE - 1)) 94 + sizeof(struct thread_info)); 95 } 96 97 #endif 98 99 /* 100 * thread information flags 101 * - these are process state flags that various assembly files may need to 102 * access 103 * - pending work-to-be-done flags are in LSW 104 * - other flags in MSW 105 */ 106 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ 107 #define TIF_SIGPENDING 1 /* signal pending */ 108 #define TIF_NEED_RESCHED 2 /* rescheduling necessary */ 109 #define TIF_SINGLESTEP 3 /* restore singlestep on return to user 110 mode */ 111 #define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */ 112 #define TIF_SECCOMP 5 /* secure computing */ 113 #define TIF_RESTORE_SIGMASK 6 /* restore signal mask in do_signal() */ 114 #define TIF_NOTIFY_RESUME 7 /* callback before returning to user */ 115 #define TIF_MEMDIE 8 /* is terminating due to OOM killer */ 116 #define TIF_SYSCALL_TRACEPOINT 9 /* syscall tracepoint instrumentation */ 117 118 119 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) 120 #define _TIF_SIGPENDING (1<<TIF_SIGPENDING) 121 #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) 122 #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP) 123 #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT) 124 #define _TIF_SECCOMP (1<<TIF_SECCOMP) 125 #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) 126 #define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK) 127 #define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT) 128 129 /* work to do in syscall trace */ 130 #define _TIF_WORK_SYSCALL_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \ 131 _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \ 132 _TIF_SYSCALL_TRACEPOINT) 133 134 /* work to do on any return to u-space */ 135 #define _TIF_ALLWORK_MASK (_TIF_SYSCALL_TRACE | _TIF_SIGPENDING | \ 136 _TIF_NEED_RESCHED | _TIF_SYSCALL_AUDIT | \ 137 _TIF_SINGLESTEP | _TIF_RESTORE_SIGMASK | \ 138 _TIF_NOTIFY_RESUME) 139 140 /* work to do on interrupt/exception return */ 141 #define _TIF_WORK_MASK (_TIF_ALLWORK_MASK & ~(_TIF_SYSCALL_TRACE | \ 142 _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP)) 143 144 #endif /* _ASM_THREAD_INFO_H */ 145