1 /*
2 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation, version 2.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
12 * NON INFRINGEMENT. See the GNU General Public License for
13 * more details.
14 */
15
16 #ifndef _ASM_TILE_THREAD_INFO_H
17 #define _ASM_TILE_THREAD_INFO_H
18
19 #include <asm/processor.h>
20 #include <asm/page.h>
21 #ifndef __ASSEMBLY__
22
23 /*
24 * Low level task data that assembly code needs immediate access to.
25 * The structure is placed at the bottom of the supervisor stack.
26 */
27 struct thread_info {
28 struct task_struct *task; /* main task structure */
29 struct exec_domain *exec_domain; /* execution domain */
30 unsigned long flags; /* low level flags */
31 unsigned long status; /* thread-synchronous flags */
32 __u32 homecache_cpu; /* CPU we are homecached on */
33 __u32 cpu; /* current CPU */
34 int preempt_count; /* 0 => preemptable,
35 <0 => BUG */
36
37 mm_segment_t addr_limit; /* thread address space
38 (KERNEL_DS or USER_DS) */
39 struct restart_block restart_block;
40 struct single_step_state *step_state; /* single step state
41 (if non-zero) */
42 };
43
44 /*
45 * macros/functions for gaining access to the thread information structure.
46 */
47 #define INIT_THREAD_INFO(tsk) \
48 { \
49 .task = &tsk, \
50 .exec_domain = &default_exec_domain, \
51 .flags = 0, \
52 .cpu = 0, \
53 .preempt_count = INIT_PREEMPT_COUNT, \
54 .addr_limit = KERNEL_DS, \
55 .restart_block = { \
56 .fn = do_no_restart_syscall, \
57 }, \
58 .step_state = NULL, \
59 }
60
61 #define init_thread_info (init_thread_union.thread_info)
62 #define init_stack (init_thread_union.stack)
63
64 #endif /* !__ASSEMBLY__ */
65
66 #if PAGE_SIZE < 8192
67 #define THREAD_SIZE_ORDER (13 - PAGE_SHIFT)
68 #else
69 #define THREAD_SIZE_ORDER (0)
70 #endif
71 #define THREAD_SIZE_PAGES (1 << THREAD_SIZE_ORDER)
72
73 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
74 #define LOG2_THREAD_SIZE (PAGE_SHIFT + THREAD_SIZE_ORDER)
75
76 #define STACK_WARN (THREAD_SIZE/8)
77
78 #ifndef __ASSEMBLY__
79
80 /* How to get the thread information struct from C. */
81 register unsigned long stack_pointer __asm__("sp");
82
83 #define current_thread_info() \
84 ((struct thread_info *)(stack_pointer & -THREAD_SIZE))
85
86 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
87 extern struct thread_info *alloc_thread_info_node(struct task_struct *task, int node);
88 extern void free_thread_info(struct thread_info *info);
89
90 /* Sit on a nap instruction until interrupted. */
91 extern void smp_nap(void);
92
93 /* Enable interrupts racelessly and nap forever: helper for cpu_idle(). */
94 extern void _cpu_idle(void);
95
96 /* Switch boot idle thread to a freshly-allocated stack and free old stack. */
97 extern void cpu_idle_on_new_stack(struct thread_info *old_ti,
98 unsigned long new_sp,
99 unsigned long new_ss10);
100
101 #else /* __ASSEMBLY__ */
102
103 /*
104 * How to get the thread information struct from assembly.
105 * Note that we use different macros since different architectures
106 * have different semantics in their "mm" instruction and we would
107 * like to guarantee that the macro expands to exactly one instruction.
108 */
109 #ifdef __tilegx__
110 #define EXTRACT_THREAD_INFO(reg) mm reg, zero, LOG2_THREAD_SIZE, 63
111 #else
112 #define GET_THREAD_INFO(reg) mm reg, sp, zero, LOG2_THREAD_SIZE, 31
113 #endif
114
115 #endif /* !__ASSEMBLY__ */
116
117 #define PREEMPT_ACTIVE 0x10000000
118
119 /*
120 * Thread information flags that various assembly files may need to access.
121 * Keep flags accessed frequently in low bits, particular since it makes
122 * it easier to build constants in assembly.
123 */
124 #define TIF_SIGPENDING 0 /* signal pending */
125 #define TIF_NEED_RESCHED 1 /* rescheduling necessary */
126 #define TIF_SINGLESTEP 2 /* restore singlestep on return to
127 user mode */
128 #define TIF_ASYNC_TLB 3 /* got an async TLB fault in kernel */
129 #define TIF_SYSCALL_TRACE 4 /* syscall trace active */
130 #define TIF_SYSCALL_AUDIT 5 /* syscall auditing active */
131 #define TIF_SECCOMP 6 /* secure computing */
132 #define TIF_MEMDIE 7 /* OOM killer at work */
133 #define TIF_NOTIFY_RESUME 8 /* callback before returning to user */
134
135 #define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
136 #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
137 #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
138 #define _TIF_ASYNC_TLB (1<<TIF_ASYNC_TLB)
139 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
140 #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
141 #define _TIF_SECCOMP (1<<TIF_SECCOMP)
142 #define _TIF_MEMDIE (1<<TIF_MEMDIE)
143 #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
144
145 /* Work to do on any return to user space. */
146 #define _TIF_ALLWORK_MASK \
147 (_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SINGLESTEP|\
148 _TIF_ASYNC_TLB|_TIF_NOTIFY_RESUME)
149
150 /*
151 * Thread-synchronous status.
152 *
153 * This is different from the flags in that nobody else
154 * ever touches our thread-synchronous status, so we don't
155 * have to worry about atomic accesses.
156 */
157 #ifdef __tilegx__
158 #define TS_COMPAT 0x0001 /* 32-bit compatibility mode */
159 #endif
160 #define TS_POLLING 0x0004 /* in idle loop but not sleeping */
161 #define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal */
162
163 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
164
165 #ifndef __ASSEMBLY__
166 #define HAVE_SET_RESTORE_SIGMASK 1
set_restore_sigmask(void)167 static inline void set_restore_sigmask(void)
168 {
169 struct thread_info *ti = current_thread_info();
170 ti->status |= TS_RESTORE_SIGMASK;
171 set_bit(TIF_SIGPENDING, &ti->flags);
172 }
173 #endif /* !__ASSEMBLY__ */
174
175 #endif /* _ASM_TILE_THREAD_INFO_H */
176