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