1 /* thread_info.h: i386 low-level thread information
3 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
4 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
7 #ifndef _ASM_THREAD_INFO_H
8 #define _ASM_THREAD_INFO_H
12 #include <linux/compiler.h>
16 #include <asm/processor.h>
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 also be changed
28 struct task_struct
*task
; /* main task structure */
29 struct exec_domain
*exec_domain
; /* execution domain */
30 unsigned long flags
; /* low level flags */
31 unsigned long status
; /* thread-synchronous flags */
32 __u32 cpu
; /* current CPU */
33 int preempt_count
; /* 0 => preemptable, <0 => BUG */
36 mm_segment_t addr_limit
; /* thread address space:
37 0-0xBFFFFFFF for user-thead
38 0-0xFFFFFFFF for kernel-thread
40 void *sysenter_return
;
41 struct restart_block restart_block
;
43 unsigned long previous_esp
; /* ESP of the previous stack in case
44 of nested (IRQ) stacks
46 __u8 supervisor_stack
[0];
49 #else /* !__ASSEMBLY__ */
51 #include <asm/asm-offsets.h>
55 #define PREEMPT_ACTIVE 0x10000000
56 #ifdef CONFIG_4KSTACKS
57 #define THREAD_SIZE (4096)
59 #define THREAD_SIZE (8192)
62 #define STACK_WARN (THREAD_SIZE/8)
64 * macros/functions for gaining access to the thread information structure
66 * preempt_count needs to be 1 initially, until the scheduler is functional.
70 #define INIT_THREAD_INFO(tsk) \
73 .exec_domain = &default_exec_domain, \
77 .addr_limit = KERNEL_DS, \
79 .fn = do_no_restart_syscall, \
83 #define init_thread_info (init_thread_union.thread_info)
84 #define init_stack (init_thread_union.stack)
87 /* how to get the current stack pointer from C */
88 register unsigned long current_stack_pointer
asm("esp") __attribute_used__
;
90 /* how to get the thread information struct from C */
91 static inline struct thread_info
*current_thread_info(void)
93 return (struct thread_info
*)(current_stack_pointer
& ~(THREAD_SIZE
- 1));
96 /* thread information allocation */
97 #ifdef CONFIG_DEBUG_STACK_USAGE
98 #define alloc_thread_info(tsk) ((struct thread_info *) \
99 __get_free_pages(GFP_KERNEL| __GFP_ZERO, get_order(THREAD_SIZE)))
101 #define alloc_thread_info(tsk) ((struct thread_info *) \
102 __get_free_pages(GFP_KERNEL, get_order(THREAD_SIZE)))
105 #define free_thread_info(info) free_pages((unsigned long)(info), get_order(THREAD_SIZE))
107 #else /* !__ASSEMBLY__ */
109 /* how to get the thread information struct from ASM */
110 #define GET_THREAD_INFO(reg) \
111 movl $-THREAD_SIZE, reg; \
114 /* use this one if reg already contains %esp */
115 #define GET_THREAD_INFO_WITH_ESP(reg) \
116 andl $-THREAD_SIZE, reg
121 * thread information flags
122 * - these are process state flags that various assembly files may need to access
123 * - pending work-to-be-done flags are in LSW
124 * - other flags in MSW
126 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
127 #define TIF_SIGPENDING 1 /* signal pending */
128 #define TIF_NEED_RESCHED 2 /* rescheduling necessary */
129 #define TIF_SINGLESTEP 3 /* restore singlestep on return to user mode */
130 #define TIF_IRET 4 /* return with iret */
131 #define TIF_SYSCALL_EMU 5 /* syscall emulation active */
132 #define TIF_SYSCALL_AUDIT 6 /* syscall auditing active */
133 #define TIF_SECCOMP 7 /* secure computing */
134 #define TIF_RESTORE_SIGMASK 8 /* restore signal mask in do_signal() */
135 #define TIF_HRTICK_RESCHED 9 /* reprogram hrtick timer */
136 #define TIF_MEMDIE 16
137 #define TIF_DEBUG 17 /* uses debug registers */
138 #define TIF_IO_BITMAP 18 /* uses I/O bitmap */
139 #define TIF_FREEZE 19 /* is freezing for suspend */
140 #define TIF_NOTSC 20 /* TSC is not accessible in userland */
142 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
143 #define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
144 #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
145 #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
146 #define _TIF_IRET (1<<TIF_IRET)
147 #define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU)
148 #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
149 #define _TIF_SECCOMP (1<<TIF_SECCOMP)
150 #define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
151 #define _TIF_HRTICK_RESCHED (1<<TIF_HRTICK_RESCHED)
152 #define _TIF_DEBUG (1<<TIF_DEBUG)
153 #define _TIF_IO_BITMAP (1<<TIF_IO_BITMAP)
154 #define _TIF_FREEZE (1<<TIF_FREEZE)
155 #define _TIF_NOTSC (1<<TIF_NOTSC)
157 /* work to do on interrupt/exception return */
158 #define _TIF_WORK_MASK \
159 (0x0000FFFF & ~(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
160 _TIF_SECCOMP | _TIF_SYSCALL_EMU))
161 /* work to do on any return to u-space */
162 #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
164 /* flags to check in __switch_to() */
165 #define _TIF_WORK_CTXSW_NEXT (_TIF_IO_BITMAP | _TIF_NOTSC | _TIF_DEBUG)
166 #define _TIF_WORK_CTXSW_PREV (_TIF_IO_BITMAP | _TIF_NOTSC)
169 * Thread-synchronous status.
171 * This is different from the flags in that nobody else
172 * ever touches our thread-synchronous status, so we don't
173 * have to worry about atomic accesses.
175 #define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */
176 #define TS_POLLING 0x0002 /* True if in idle loop and not sleeping */
178 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
180 #endif /* __KERNEL__ */
182 #endif /* _ASM_THREAD_INFO_H */