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/* thread_info.h: description
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* Derived from include/asm-i386/thread_info.h
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H
#ifdef __KERNEL__
#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;
__u8 supervisor_stack[0];
};
#else /* !__ASSEMBLY__ */
/* offsets into the thread_info struct for assembly code access */
#define TI_TASK 0x00000000
#define TI_EXEC_DOMAIN 0x00000004
#define TI_FLAGS 0x00000008
#define TI_STATUS 0x0000000C
#define TI_CPU 0x00000010
#define TI_PRE_COUNT 0x00000014
#define TI_ADDR_LIMIT 0x00000018
#define TI_RESTART_BLOCK 0x0000001C
#endif
#define PREEMPT_ACTIVE 0x10000000
/*
* 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)
#ifdef CONFIG_SMALL_TASKS
#define THREAD_SIZE 4096
#else
#define THREAD_SIZE 8192
#endif
/* how to get the thread information struct from C */
register struct thread_info *__current_thread_info asm("gr15");
#define current_thread_info() ({ __current_thread_info; })
/* 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)
#else /* !__ASSEMBLY__ */
#define THREAD_SIZE 8192
#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_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17 /* OOM killer killed process */
#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_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
/*
* 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_USEDFPM 0x0001 /* FPU/Media was used by this task this quantum (SMP) */
#endif /* __KERNEL__ */
#endif /* _ASM_THREAD_INFO_H */
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