1/*
2 * include/asm-xtensa/thread_info.h
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License.  See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 2001 - 2005 Tensilica Inc.
9 */
10
11#ifndef _XTENSA_THREAD_INFO_H
12#define _XTENSA_THREAD_INFO_H
13
14#ifdef __KERNEL__
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
25 *   must also be changed
26 */
27
28#ifndef __ASSEMBLY__
29
30struct thread_info {
31	struct task_struct	*task;		/* main task structure */
32	struct exec_domain	*exec_domain;	/* execution domain */
33	unsigned long		flags;		/* low level flags */
34	unsigned long		status;		/* thread-synchronous flags */
35	__u32			cpu;		/* current CPU */
36	__s32			preempt_count;	/* 0 => preemptable,< 0 => BUG*/
37
38	mm_segment_t		addr_limit;	/* thread address space */
39	struct restart_block    restart_block;
40
41
42};
43
44#else /* !__ASSEMBLY__ */
45
46/* offsets into the thread_info struct for assembly code access */
47#define TI_TASK		 0x00000000
48#define TI_EXEC_DOMAIN	 0x00000004
49#define TI_FLAGS	 0x00000008
50#define TI_STATUS	 0x0000000C
51#define TI_CPU		 0x00000010
52#define TI_PRE_COUNT	 0x00000014
53#define TI_ADDR_LIMIT	 0x00000018
54#define TI_RESTART_BLOCK 0x000001C
55
56#endif
57
58#define PREEMPT_ACTIVE		0x10000000
59
60/*
61 * macros/functions for gaining access to the thread information structure
62 *
63 * preempt_count needs to be 1 initially, until the scheduler is functional.
64 */
65
66#ifndef __ASSEMBLY__
67
68#define INIT_THREAD_INFO(tsk)			\
69{						\
70	.task		= &tsk,			\
71	.exec_domain	= &default_exec_domain,	\
72	.flags		= 0,			\
73	.cpu		= 0,			\
74	.preempt_count	= 1,			\
75	.addr_limit	= KERNEL_DS,		\
76	.restart_block = {			\
77		.fn = do_no_restart_syscall,	\
78	},					\
79}
80
81#define init_thread_info	(init_thread_union.thread_info)
82#define init_stack		(init_thread_union.stack)
83
84/* how to get the thread information struct from C */
85static inline struct thread_info *current_thread_info(void)
86{
87	struct thread_info *ti;
88	 __asm__("extui %0,a1,0,13\n\t"
89	         "xor %0, a1, %0" : "=&r" (ti) : );
90	return ti;
91}
92
93/* thread information allocation */
94#define alloc_thread_info(tsk) ((struct thread_info *) __get_free_pages(GFP_KERNEL,1))
95#define free_thread_info(ti) free_pages((unsigned long) (ti), 1)
96
97#else /* !__ASSEMBLY__ */
98
99/* how to get the thread information struct from ASM */
100#define GET_THREAD_INFO(reg,sp) \
101	extui reg, sp, 0, 13; \
102	xor   reg, sp, reg
103#endif
104
105
106/*
107 * thread information flags
108 * - these are process state flags that various assembly files may need to access
109 * - pending work-to-be-done flags are in LSW
110 * - other flags in MSW
111 */
112#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
113#define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
114#define TIF_SIGPENDING		2	/* signal pending */
115#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
116#define TIF_SINGLESTEP		4	/* restore singlestep on return to user mode */
117#define TIF_IRET		5	/* return with iret */
118#define TIF_MEMDIE		6
119#define TIF_RESTORE_SIGMASK	7	/* restore signal mask in do_signal() */
120#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
121
122#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
123#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
124#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
125#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
126#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
127#define _TIF_IRET		(1<<TIF_IRET)
128#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
129#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
130
131#define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
132#define _TIF_ALLWORK_MASK	0x0000FFFF	/* work to do on any return to u-space */
133
134/*
135 * Thread-synchronous status.
136 *
137 * This is different from the flags in that nobody else
138 * ever touches our thread-synchronous status, so we don't
139 * have to worry about atomic accesses.
140 */
141#define TS_USEDFPU		0x0001	/* FPU was used by this task this quantum (SMP) */
142
143#define THREAD_SIZE 8192	//(2*PAGE_SIZE)
144
145#endif	/* __KERNEL__ */
146#endif	/* _XTENSA_THREAD_INFO */
147