1 /*
2  *  Port on Texas Instruments TMS320C6x architecture
3  *
4  *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
5  *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
6  *
7  *  Updated for 2.6.3x: Mark Salter <msalter@redhat.com>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2 as
11  *  published by the Free Software Foundation.
12  */
13 #ifndef _ASM_C6X_THREAD_INFO_H
14 #define _ASM_C6X_THREAD_INFO_H
15 
16 #ifdef __KERNEL__
17 
18 #include <asm/page.h>
19 
20 #ifdef CONFIG_4KSTACKS
21 #define THREAD_SIZE		4096
22 #define THREAD_SHIFT		12
23 #define THREAD_SIZE_ORDER	0
24 #else
25 #define THREAD_SIZE		8192
26 #define THREAD_SHIFT		13
27 #define THREAD_SIZE_ORDER	1
28 #endif
29 
30 #define THREAD_START_SP		(THREAD_SIZE - 8)
31 
32 #ifndef __ASSEMBLY__
33 
34 typedef struct {
35 	unsigned long seg;
36 } mm_segment_t;
37 
38 /*
39  * low level task data.
40  */
41 struct thread_info {
42 	struct task_struct	*task;		/* main task structure */
43 	unsigned long		flags;		/* low level flags */
44 	int			cpu;		/* cpu we're on */
45 	int			preempt_count;	/* 0 = preemptable, <0 = BUG */
46 	mm_segment_t		addr_limit;	/* thread address space */
47 };
48 
49 /*
50  * macros/functions for gaining access to the thread information structure
51  *
52  * preempt_count needs to be 1 initially, until the scheduler is functional.
53  */
54 #define INIT_THREAD_INFO(tsk)			\
55 {						\
56 	.task		= &tsk,			\
57 	.flags		= 0,			\
58 	.cpu		= 0,			\
59 	.preempt_count	= INIT_PREEMPT_COUNT,	\
60 	.addr_limit	= KERNEL_DS,		\
61 }
62 
63 #define init_thread_info	(init_thread_union.thread_info)
64 #define init_stack		(init_thread_union.stack)
65 
66 /* get the thread information struct of current task */
67 static inline __attribute__((const))
current_thread_info(void)68 struct thread_info *current_thread_info(void)
69 {
70 	struct thread_info *ti;
71 	asm volatile (" clr   .s2 B15,0,%1,%0\n"
72 		      : "=b" (ti)
73 		      : "Iu5" (THREAD_SHIFT - 1));
74 	return ti;
75 }
76 
77 #define get_thread_info(ti)	get_task_struct((ti)->task)
78 #define put_thread_info(ti)	put_task_struct((ti)->task)
79 #endif /* __ASSEMBLY__ */
80 
81 /*
82  * thread information flag bit numbers
83  * - pending work-to-be-done flags are in LSW
84  * - other flags in MSW
85  */
86 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
87 #define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
88 #define TIF_SIGPENDING		2	/* signal pending */
89 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
90 #define TIF_RESTORE_SIGMASK	4	/* restore signal mask in do_signal() */
91 
92 #define TIF_MEMDIE		17	/* OOM killer killed process */
93 
94 #define TIF_WORK_MASK		0x00007FFE /* work on irq/exception return */
95 #define TIF_ALLWORK_MASK	0x00007FFF /* work on any return to u-space */
96 
97 #endif /* __KERNEL__ */
98 
99 #endif /* _ASM_C6X_THREAD_INFO_H */
100