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 #include <asm/kmem_layout.h>
15 
16 #define CURRENT_SHIFT KERNEL_STACK_SHIFT
17 
18 #ifndef __ASSEMBLY__
19 # include <asm/processor.h>
20 #endif
21 
22 /*
23  * low level task data that entry.S needs immediate access to
24  * - this struct should fit entirely inside of one cache line
25  * - this struct shares the supervisor stack pages
26  * - if the contents of this structure are changed, the assembly constants
27  *   must also be changed
28  */
29 
30 #ifndef __ASSEMBLY__
31 
32 #if XTENSA_HAVE_COPROCESSORS
33 
34 typedef struct xtregs_coprocessor {
35 	xtregs_cp0_t cp0;
36 	xtregs_cp1_t cp1;
37 	xtregs_cp2_t cp2;
38 	xtregs_cp3_t cp3;
39 	xtregs_cp4_t cp4;
40 	xtregs_cp5_t cp5;
41 	xtregs_cp6_t cp6;
42 	xtregs_cp7_t cp7;
43 } xtregs_coprocessor_t;
44 
45 #endif
46 
47 struct thread_info {
48 	struct task_struct	*task;		/* main task structure */
49 	unsigned long		flags;		/* low level flags */
50 	unsigned long		status;		/* thread-synchronous flags */
51 	__u32			cpu;		/* current CPU */
52 	__s32			preempt_count;	/* 0 => preemptable,< 0 => BUG*/
53 
54 	mm_segment_t		addr_limit;	/* thread address space */
55 
56 	unsigned long		cpenable;
57 
58 	/* Allocate storage for extra user states and coprocessor states. */
59 #if XTENSA_HAVE_COPROCESSORS
60 	xtregs_coprocessor_t	xtregs_cp;
61 #endif
62 	xtregs_user_t		xtregs_user;
63 };
64 
65 #endif
66 
67 /*
68  * macros/functions for gaining access to the thread information structure
69  */
70 
71 #ifndef __ASSEMBLY__
72 
73 #define INIT_THREAD_INFO(tsk)			\
74 {						\
75 	.task		= &tsk,			\
76 	.flags		= 0,			\
77 	.cpu		= 0,			\
78 	.preempt_count	= INIT_PREEMPT_COUNT,	\
79 	.addr_limit	= KERNEL_DS,		\
80 }
81 
82 /* how to get the thread information struct from C */
83 static inline struct thread_info *current_thread_info(void)
84 {
85 	struct thread_info *ti;
86 	 __asm__("extui %0, a1, 0, "__stringify(CURRENT_SHIFT)"\n\t"
87 	         "xor %0, a1, %0" : "=&r" (ti) : );
88 	return ti;
89 }
90 
91 #else /* !__ASSEMBLY__ */
92 
93 /* how to get the thread information struct from ASM */
94 #define GET_THREAD_INFO(reg,sp) \
95 	extui reg, sp, 0, CURRENT_SHIFT; \
96 	xor   reg, sp, reg
97 #endif
98 
99 
100 /*
101  * thread information flags
102  * - these are process state flags that various assembly files may need to access
103  * - pending work-to-be-done flags are in LSW
104  * - other flags in MSW
105  */
106 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
107 #define TIF_SIGPENDING		1	/* signal pending */
108 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
109 #define TIF_SINGLESTEP		3	/* restore singlestep on return to user mode */
110 #define TIF_MEMDIE		5	/* is terminating due to OOM killer */
111 #define TIF_RESTORE_SIGMASK	6	/* restore signal mask in do_signal() */
112 #define TIF_NOTIFY_RESUME	7	/* callback before returning to user */
113 #define TIF_DB_DISABLED		8	/* debug trap disabled for syscall */
114 
115 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
116 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
117 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
118 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
119 
120 #define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
121 #define _TIF_ALLWORK_MASK	0x0000FFFF	/* work to do on any return to u-space */
122 
123 /*
124  * Thread-synchronous status.
125  *
126  * This is different from the flags in that nobody else
127  * ever touches our thread-synchronous status, so we don't
128  * have to worry about atomic accesses.
129  */
130 #define TS_USEDFPU		0x0001	/* FPU was used by this task this quantum (SMP) */
131 
132 #define THREAD_SIZE KERNEL_STACK_SIZE
133 #define THREAD_SIZE_ORDER (KERNEL_STACK_SHIFT - PAGE_SHIFT)
134 
135 #endif	/* _XTENSA_THREAD_INFO */
136