[linux-block.git] / include / asm-i386 / thread_info.h

/* thread_info.h: i386 low-level thread information
 *
 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#ifdef __KERNEL__

#include <linux/config.h>
#include <linux/compiler.h>
#include <asm/page.h>

#ifndef __ASSEMBLY__
#include <asm/processor.h>
#endif

/*
 * low level task data that entry.S needs immediate access to
 * - this struct should fit entirely inside of one cache line
 * - this struct shares the supervisor stack pages
 * - if the contents of this structure are changed, the assembly constants must also be changed
 */
#ifndef __ASSEMBLY__

struct thread_info {
	struct task_struct	*task;		/* main task structure */
	struct exec_domain	*exec_domain;	/* execution domain */
	unsigned long		flags;		/* low level flags */
	unsigned long		status;		/* thread-synchronous flags */
	__u32			cpu;		/* current CPU */
	int			preempt_count;	/* 0 => preemptable, <0 => BUG */


	mm_segment_t		addr_limit;	/* thread address space:
					 	   0-0xBFFFFFFF for user-thead
						   0-0xFFFFFFFF for kernel-thread
						*/
	struct restart_block    restart_block;

	unsigned long           previous_esp;   /* ESP of the previous stack in case
						   of nested (IRQ) stacks
						*/
	__u8			supervisor_stack[0];
};

#else /* !__ASSEMBLY__ */

#include <asm/asm-offsets.h>

#endif

#define PREEMPT_ACTIVE		0x10000000
#ifdef CONFIG_4KSTACKS
#define THREAD_SIZE            (4096)
#else
#define THREAD_SIZE		(8192)
#endif

#define STACK_WARN             (THREAD_SIZE/8)
/*
 * macros/functions for gaining access to the thread information structure
 *
 * preempt_count needs to be 1 initially, until the scheduler is functional.
 */
#ifndef __ASSEMBLY__

#define INIT_THREAD_INFO(tsk)			\
{						\
	.task		= &tsk,			\
	.exec_domain	= &default_exec_domain,	\
	.flags		= 0,			\
	.cpu		= 0,			\
	.preempt_count	= 1,			\
	.addr_limit	= KERNEL_DS,		\
	.restart_block = {			\
		.fn = do_no_restart_syscall,	\
	},					\
}

#define init_thread_info	(init_thread_union.thread_info)
#define init_stack		(init_thread_union.stack)


/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
	struct thread_info *ti;
	__asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
	return ti;
}

/* how to get the current stack pointer from C */
register unsigned long current_stack_pointer asm("esp") __attribute_used__;

/* thread information allocation */
#ifdef CONFIG_DEBUG_STACK_USAGE
#define alloc_thread_info(tsk)					\
	({							\
		struct thread_info *ret;			\
								\
		ret = kmalloc(THREAD_SIZE, GFP_KERNEL);		\
		if (ret)					\
			memset(ret, 0, THREAD_SIZE);		\
		ret;						\
	})
#else
#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
#endif

#define free_thread_info(info)	kfree(info)
#define get_thread_info(ti) get_task_struct((ti)->task)
#define put_thread_info(ti) put_task_struct((ti)->task)

#else /* !__ASSEMBLY__ */

/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg) \
	movl $-THREAD_SIZE, reg; \
	andl %esp, reg

/* use this one if reg already contains %esp */
#define GET_THREAD_INFO_WITH_ESP(reg) \
	andl $-THREAD_SIZE, reg

#endif

/*
 * thread information flags
 * - these are process state flags that various assembly files may need to access
 * - pending work-to-be-done flags are in LSW
 * - other flags in MSW
 */
#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
#define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
#define TIF_SIGPENDING		2	/* signal pending */
#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
#define TIF_SINGLESTEP		4	/* restore singlestep on return to user mode */
#define TIF_IRET		5	/* return with iret */
#define TIF_SYSCALL_EMU		6	/* syscall emulation active */
#define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
#define TIF_SECCOMP		8	/* secure computing */
#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE		17

#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
#define _TIF_IRET		(1<<TIF_IRET)
#define _TIF_SYSCALL_EMU	(1<<TIF_SYSCALL_EMU)
#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP		(1<<TIF_SECCOMP)
#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)

/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK \
  (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP|\
		  _TIF_SECCOMP|_TIF_SYSCALL_EMU))
/* work to do on any return to u-space */
#define _TIF_ALLWORK_MASK	(0x0000FFFF & ~_TIF_SECCOMP)

/*
 * Thread-synchronous status.
 *
 * This is different from the flags in that nobody else
 * ever touches our thread-synchronous status, so we don't
 * have to worry about atomic accesses.
 */
#define TS_USEDFPU		0x0001	/* FPU was used by this task this quantum (SMP) */

#endif /* __KERNEL__ */

#endif /* _ASM_THREAD_INFO_H */
Commit	Line	Data
1da177e4 LT	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
	12	#include <linux/config.h>
	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 also be changed
	25	*/
	26	#ifndef __ASSEMBLY__
	27
	28	struct thread_info {
	29	struct task_struct task; / main task structure */
	30	struct exec_domain exec_domain; / execution domain */
	31	unsigned long flags; /* low level flags */
	32	unsigned long status; /* thread-synchronous flags */
	33	__u32 cpu; /* current CPU */
dcd497f9	34	int preempt_count; /* 0 => preemptable, <0 => BUG */
1da177e4 LT	35
	36
	37	mm_segment_t addr_limit; /* thread address space:
	38	0-0xBFFFFFFF for user-thead
	39	0-0xFFFFFFFF for kernel-thread
	40	*/
	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
86feeaa8	51	#include <asm/asm-offsets.h>
1da177e4 LT	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
	87	/* how to get the thread information struct from C */
	88	static inline struct thread_info *current_thread_info(void)
	89	{
	90	struct thread_info *ti;
	91	__asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
	92	return ti;
	93	}
	94
	95	/* how to get the current stack pointer from C */
	96	register unsigned long current_stack_pointer asm("esp") __attribute_used__;
	97
	98	/* thread information allocation */
	99	#ifdef CONFIG_DEBUG_STACK_USAGE
	100	#define alloc_thread_info(tsk) \
	101	({ \
	102	struct thread_info *ret; \
	103	\
	104	ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
	105	if (ret) \
	106	memset(ret, 0, THREAD_SIZE); \
	107	ret; \
	108	})
	109	#else
	110	#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
	111	#endif
	112
	113	#define free_thread_info(info) kfree(info)
	114	#define get_thread_info(ti) get_task_struct((ti)->task)
	115	#define put_thread_info(ti) put_task_struct((ti)->task)
116
117	#else /* !__ASSEMBLY__ */
118
119	/* how to get the thread information struct from ASM */
120	#define GET_THREAD_INFO(reg) \
121	movl $-THREAD_SIZE, reg; \
122	andl %esp, reg
123
124	/* use this one if reg already contains %esp */
125	#define GET_THREAD_INFO_WITH_ESP(reg) \
126	andl $-THREAD_SIZE, reg
127
128	#endif
129
130	/*
131	* thread information flags
132	* - these are process state flags that various assembly files may need to access
133	* - pending work-to-be-done flags are in LSW
134	* - other flags in MSW
135	*/
136	#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
137	#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
138	#define TIF_SIGPENDING 2 /* signal pending */
139	#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
140	#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
141	#define TIF_IRET 5 /* return with iret */
ed75e8d5	142	#define TIF_SYSCALL_EMU 6 /* syscall emulation active */
1da177e4 LT	143	#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
	144	#define TIF_SECCOMP 8 /* secure computing */
	145	#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
	146	#define TIF_MEMDIE 17
	147
	148	#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
	149	#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
	150	#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
	151	#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
	152	#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
	153	#define _TIF_IRET (1<<TIF_IRET)
ed75e8d5	154	#define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU)
1da177e4 LT	155	#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
	156	#define _TIF_SECCOMP (1<<TIF_SECCOMP)
	157	#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
	158
	159	/* work to do on interrupt/exception return */
	160	#define _TIF_WORK_MASK \
ed75e8d5 LV	161	(0x0000FFFF & ~(_TIF_SYSCALL_TRACE\|_TIF_SYSCALL_AUDIT\|_TIF_SINGLESTEP\|\
ed75e8d5 LV	162	_TIF_SECCOMP\|_TIF_SYSCALL_EMU))
1da177e4 LT	163	/* work to do on any return to u-space */
	164	#define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
	165
	166	/*
	167	* Thread-synchronous status.
	168	*
	169	* This is different from the flags in that nobody else
	170	* ever touches our thread-synchronous status, so we don't
	171	* have to worry about atomic accesses.
	172	*/
	173	#define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */
	174
	175	#endif /* __KERNEL__ */
	176
	177	#endif /* _ASM_THREAD_INFO_H */