1/* thread_info.h: x86_64 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 7#ifndef _ASM_THREAD_INFO_H 8#define _ASM_THREAD_INFO_H 9 10#ifdef __KERNEL__ 11 12#include <asm/page.h> 13#include <asm/types.h> 14#include <asm/pda.h> 15 16/* 17 * low level task data that entry.S needs immediate access to 18 * - this struct should fit entirely inside of one cache line 19 * - this struct shares the supervisor stack pages 20 */ 21#ifndef __ASSEMBLY__ 22struct task_struct; 23struct exec_domain; 24#include <asm/mmsegment.h> 25 26struct thread_info { 27 struct task_struct *task; /* main task structure */ 28 struct exec_domain *exec_domain; /* execution domain */ 29 __u32 flags; /* low level flags */ 30 __u32 status; /* thread synchronous flags */ 31 __u32 cpu; /* current CPU */ 32 int preempt_count; /* 0 => preemptable, <0 => BUG */ 33 34 mm_segment_t addr_limit; 35 struct restart_block restart_block; 36}; 37#endif 38 39/* 40 * macros/functions for gaining access to the thread information structure 41 * preempt_count needs to be 1 initially, until the scheduler is functional. 42 */ 43#ifndef __ASSEMBLY__ 44#define INIT_THREAD_INFO(tsk) \ 45{ \ 46 .task = &tsk, \ 47 .exec_domain = &default_exec_domain, \ 48 .flags = 0, \ 49 .cpu = 0, \ 50 .preempt_count = 1, \ 51 .addr_limit = KERNEL_DS, \ 52 .restart_block = { \ 53 .fn = do_no_restart_syscall, \ 54 }, \ 55} 56 57#define init_thread_info (init_thread_union.thread_info) 58#define init_stack (init_thread_union.stack) 59 60static inline struct thread_info *current_thread_info(void) 61{ 62 struct thread_info *ti; 63 ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE); 64 return ti; 65} 66 67/* do not use in interrupt context */ 68static inline struct thread_info *stack_thread_info(void) 69{ 70 struct thread_info *ti; 71 __asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1))); 72 return ti; 73} 74 75/* thread information allocation */ 76#ifdef CONFIG_DEBUG_STACK_USAGE 77#define alloc_thread_info(tsk) \ 78 ({ \ 79 struct thread_info *ret; \ 80 \ 81 ret = ((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER)); \ 82 if (ret) \ 83 memset(ret, 0, THREAD_SIZE); \ 84 ret; \ 85 }) 86#else 87#define alloc_thread_info(tsk) \ 88 ((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER)) 89#endif 90 91#define free_thread_info(ti) free_pages((unsigned long) (ti), THREAD_ORDER) 92 93#else /* !__ASSEMBLY__ */ 94 95/* how to get the thread information struct from ASM */ 96#define GET_THREAD_INFO(reg) \ 97 movq %gs:pda_kernelstack,reg ; \ 98 subq $(THREAD_SIZE-PDA_STACKOFFSET),reg 99 100#endif 101 102/* 103 * thread information flags 104 * - these are process state flags that various assembly files may need to access 105 * - pending work-to-be-done flags are in LSW 106 * - other flags in MSW 107 * Warning: layout of LSW is hardcoded in entry.S 108 */ 109#define TIF_SYSCALL_TRACE 0 /* syscall trace active */ 110#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ 111#define TIF_SIGPENDING 2 /* signal pending */ 112#define TIF_NEED_RESCHED 3 /* rescheduling necessary */ 113#define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/ 114#define TIF_IRET 5 /* force IRET */ 115#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ 116#define TIF_SECCOMP 8 /* secure computing */ 117#define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal */ 118/* 16 free */ 119#define TIF_IA32 17 /* 32bit process */ 120#define TIF_FORK 18 /* ret_from_fork */ 121#define TIF_ABI_PENDING 19 122#define TIF_MEMDIE 20 123#define TIF_DEBUG 21 /* uses debug registers */ 124#define TIF_IO_BITMAP 22 /* uses I/O bitmap */ 125#define TIF_FREEZE 23 /* is freezing for suspend */ 126 127#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) 128#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) 129#define _TIF_SIGPENDING (1<<TIF_SIGPENDING) 130#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP) 131#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) 132#define _TIF_IRET (1<<TIF_IRET) 133#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT) 134#define _TIF_SECCOMP (1<<TIF_SECCOMP) 135#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK) 136#define _TIF_IA32 (1<<TIF_IA32) 137#define _TIF_FORK (1<<TIF_FORK) 138#define _TIF_ABI_PENDING (1<<TIF_ABI_PENDING) 139#define _TIF_DEBUG (1<<TIF_DEBUG) 140#define _TIF_IO_BITMAP (1<<TIF_IO_BITMAP) 141#define _TIF_FREEZE (1<<TIF_FREEZE) 142 143/* work to do on interrupt/exception return */ 144#define _TIF_WORK_MASK \ 145 (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP|_TIF_SECCOMP)) 146/* work to do on any return to user space */ 147#define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP) 148 149/* flags to check in __switch_to() */ 150#define _TIF_WORK_CTXSW (_TIF_DEBUG|_TIF_IO_BITMAP) 151 152#define PREEMPT_ACTIVE 0x10000000 153 154/* 155 * Thread-synchronous status. 156 * 157 * This is different from the flags in that nobody else 158 * ever touches our thread-synchronous status, so we don't 159 * have to worry about atomic accesses. 160 */ 161#define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */ 162#define TS_COMPAT 0x0002 /* 32bit syscall active */ 163#define TS_POLLING 0x0004 /* true if in idle loop and not sleeping */ 164 165#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING) 166 167#endif /* __KERNEL__ */ 168 169#endif /* _ASM_THREAD_INFO_H */ 170