Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* thread_info.h: i386 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 also be changed |
| 24 | */ |
| 25 | #ifndef __ASSEMBLY__ |
| 26 | |
| 27 | struct thread_info { |
| 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 */ |
Jesper Juhl | dcd497f | 2005-06-23 00:09:07 -0700 | [diff] [blame] | 33 | int preempt_count; /* 0 => preemptable, <0 => BUG */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
| 35 | |
| 36 | mm_segment_t addr_limit; /* thread address space: |
| 37 | 0-0xBFFFFFFF for user-thead |
| 38 | 0-0xFFFFFFFF for kernel-thread |
| 39 | */ |
Ingo Molnar | e6e5494 | 2006-06-27 02:53:50 -0700 | [diff] [blame] | 40 | void *sysenter_return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | struct restart_block restart_block; |
| 42 | |
| 43 | unsigned long previous_esp; /* ESP of the previous stack in case |
| 44 | of nested (IRQ) stacks |
| 45 | */ |
| 46 | __u8 supervisor_stack[0]; |
| 47 | }; |
| 48 | |
| 49 | #else /* !__ASSEMBLY__ */ |
| 50 | |
Sam Ravnborg | 86feeaa | 2005-09-09 19:28:28 +0200 | [diff] [blame] | 51 | #include <asm/asm-offsets.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | |
| 53 | #endif |
| 54 | |
| 55 | #define PREEMPT_ACTIVE 0x10000000 |
| 56 | #ifdef CONFIG_4KSTACKS |
| 57 | #define THREAD_SIZE (4096) |
| 58 | #else |
| 59 | #define THREAD_SIZE (8192) |
| 60 | #endif |
| 61 | |
| 62 | #define STACK_WARN (THREAD_SIZE/8) |
| 63 | /* |
| 64 | * macros/functions for gaining access to the thread information structure |
| 65 | * |
| 66 | * preempt_count needs to be 1 initially, until the scheduler is functional. |
| 67 | */ |
| 68 | #ifndef __ASSEMBLY__ |
| 69 | |
| 70 | #define INIT_THREAD_INFO(tsk) \ |
| 71 | { \ |
| 72 | .task = &tsk, \ |
| 73 | .exec_domain = &default_exec_domain, \ |
| 74 | .flags = 0, \ |
| 75 | .cpu = 0, \ |
| 76 | .preempt_count = 1, \ |
| 77 | .addr_limit = KERNEL_DS, \ |
| 78 | .restart_block = { \ |
| 79 | .fn = do_no_restart_syscall, \ |
| 80 | }, \ |
| 81 | } |
| 82 | |
| 83 | #define init_thread_info (init_thread_union.thread_info) |
| 84 | #define init_stack (init_thread_union.stack) |
| 85 | |
| 86 | |
Chuck Ebbert | c723e084 | 2006-06-27 02:53:47 -0700 | [diff] [blame] | 87 | /* how to get the current stack pointer from C */ |
| 88 | register unsigned long current_stack_pointer asm("esp") __attribute_used__; |
| 89 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | /* how to get the thread information struct from C */ |
| 91 | static inline struct thread_info *current_thread_info(void) |
| 92 | { |
Chuck Ebbert | c723e084 | 2006-06-27 02:53:47 -0700 | [diff] [blame] | 93 | return (struct thread_info *)(current_stack_pointer & ~(THREAD_SIZE - 1)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | } |
| 95 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | /* thread information allocation */ |
| 97 | #ifdef CONFIG_DEBUG_STACK_USAGE |
Christoph Lameter | b5637e6 | 2007-05-06 14:49:33 -0700 | [diff] [blame] | 98 | #define alloc_thread_info(tsk) ((struct thread_info *) \ |
| 99 | __get_free_pages(GFP_KERNEL| __GFP_ZERO, get_order(THREAD_SIZE))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | #else |
Christoph Lameter | b5637e6 | 2007-05-06 14:49:33 -0700 | [diff] [blame] | 101 | #define alloc_thread_info(tsk) ((struct thread_info *) \ |
| 102 | __get_free_pages(GFP_KERNEL, get_order(THREAD_SIZE))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | #endif |
| 104 | |
Christoph Lameter | b5637e6 | 2007-05-06 14:49:33 -0700 | [diff] [blame] | 105 | #define free_thread_info(info) free_pages((unsigned long)(info), get_order(THREAD_SIZE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | |
| 107 | #else /* !__ASSEMBLY__ */ |
| 108 | |
| 109 | /* how to get the thread information struct from ASM */ |
| 110 | #define GET_THREAD_INFO(reg) \ |
| 111 | movl $-THREAD_SIZE, reg; \ |
| 112 | andl %esp, reg |
| 113 | |
| 114 | /* use this one if reg already contains %esp */ |
| 115 | #define GET_THREAD_INFO_WITH_ESP(reg) \ |
| 116 | andl $-THREAD_SIZE, reg |
| 117 | |
| 118 | #endif |
| 119 | |
| 120 | /* |
| 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 |
| 125 | */ |
| 126 | #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ |
| 127 | #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ |
| 128 | #define TIF_SIGPENDING 2 /* signal pending */ |
| 129 | #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ |
| 130 | #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ |
| 131 | #define TIF_IRET 5 /* return with iret */ |
Laurent Vivier | ed75e8d | 2005-09-03 15:57:18 -0700 | [diff] [blame] | 132 | #define TIF_SYSCALL_EMU 6 /* syscall emulation active */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ |
| 134 | #define TIF_SECCOMP 8 /* secure computing */ |
David Howells | 283828f | 2006-01-18 17:44:00 -0800 | [diff] [blame] | 135 | #define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal() */ |
Andi Kleen | 495ab9c | 2006-06-26 13:59:11 +0200 | [diff] [blame] | 136 | #define TIF_MEMDIE 16 |
Stephane Eranian | b3cf257 | 2006-07-09 21:12:39 -0400 | [diff] [blame] | 137 | #define TIF_DEBUG 17 /* uses debug registers */ |
| 138 | #define TIF_IO_BITMAP 18 /* uses I/O bitmap */ |
Rafael J. Wysocki | 8a102ee | 2006-12-13 00:34:30 -0800 | [diff] [blame] | 139 | #define TIF_FREEZE 19 /* is freezing for suspend */ |
Andrea Arcangeli | cf99aba | 2007-07-15 23:41:33 -0700 | [diff] [blame] | 140 | #define TIF_NOTSC 20 /* TSC is not accessible in userland */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
| 142 | #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) |
| 143 | #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) |
| 144 | #define _TIF_SIGPENDING (1<<TIF_SIGPENDING) |
| 145 | #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) |
| 146 | #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP) |
| 147 | #define _TIF_IRET (1<<TIF_IRET) |
Laurent Vivier | ed75e8d | 2005-09-03 15:57:18 -0700 | [diff] [blame] | 148 | #define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT) |
| 150 | #define _TIF_SECCOMP (1<<TIF_SECCOMP) |
David Howells | 283828f | 2006-01-18 17:44:00 -0800 | [diff] [blame] | 151 | #define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK) |
Stephane Eranian | b3cf257 | 2006-07-09 21:12:39 -0400 | [diff] [blame] | 152 | #define _TIF_DEBUG (1<<TIF_DEBUG) |
| 153 | #define _TIF_IO_BITMAP (1<<TIF_IO_BITMAP) |
Rafael J. Wysocki | 8a102ee | 2006-12-13 00:34:30 -0800 | [diff] [blame] | 154 | #define _TIF_FREEZE (1<<TIF_FREEZE) |
Andrea Arcangeli | cf99aba | 2007-07-15 23:41:33 -0700 | [diff] [blame] | 155 | #define _TIF_NOTSC (1<<TIF_NOTSC) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | |
| 157 | /* work to do on interrupt/exception return */ |
| 158 | #define _TIF_WORK_MASK \ |
Chuck Ebbert | cfe91f9 | 2006-02-17 03:16:55 -0500 | [diff] [blame] | 159 | (0x0000FFFF & ~(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ |
| 160 | _TIF_SECCOMP | _TIF_SYSCALL_EMU)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | /* work to do on any return to u-space */ |
| 162 | #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP) |
| 163 | |
Stephane Eranian | b3cf257 | 2006-07-09 21:12:39 -0400 | [diff] [blame] | 164 | /* flags to check in __switch_to() */ |
Andrea Arcangeli | cf99aba | 2007-07-15 23:41:33 -0700 | [diff] [blame] | 165 | #define _TIF_WORK_CTXSW_NEXT (_TIF_IO_BITMAP | _TIF_NOTSC | _TIF_DEBUG) |
| 166 | #define _TIF_WORK_CTXSW_PREV (_TIF_IO_BITMAP | _TIF_NOTSC) |
Stephane Eranian | b3cf257 | 2006-07-09 21:12:39 -0400 | [diff] [blame] | 167 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | /* |
| 169 | * Thread-synchronous status. |
| 170 | * |
| 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. |
| 174 | */ |
| 175 | #define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */ |
Andi Kleen | 495ab9c | 2006-06-26 13:59:11 +0200 | [diff] [blame] | 176 | #define TS_POLLING 0x0002 /* True if in idle loop and not sleeping */ |
| 177 | |
Roman Zippel | c9f4f06 | 2007-05-09 02:35:16 -0700 | [diff] [blame] | 178 | #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | |
| 180 | #endif /* __KERNEL__ */ |
| 181 | |
| 182 | #endif /* _ASM_THREAD_INFO_H */ |