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 */
27struct thread_info {
28	struct task_struct	*task;		/* main task structure */
29	unsigned long		flags;		/* low level flags */
30	unsigned long		status;		/* thread-synchronous flags */
31	__u32			homecache_cpu;	/* CPU we are homecached on */
32	__u32			cpu;		/* current CPU */
33	int			preempt_count;	/* 0 => preemptable,
34						   <0 => BUG */
35
36	mm_segment_t		addr_limit;	/* thread address space
37						   (KERNEL_DS or USER_DS) */
38	struct single_step_state *step_state;	/* single step state
39						   (if non-zero) */
40	int			align_ctl;	/* controls unaligned access */
41#ifdef __tilegx__
42	unsigned long		unalign_jit_tmp[4]; /* temp r0..r3 storage */
43	void __user		*unalign_jit_base; /* unalign fixup JIT base */
44#endif
45};
46
47/*
48 * macros/functions for gaining access to the thread information structure.
49 */
50#define INIT_THREAD_INFO(tsk)			\
51{						\
52	.task		= &tsk,			\
53	.flags		= 0,			\
54	.cpu		= 0,			\
55	.preempt_count	= INIT_PREEMPT_COUNT,	\
56	.addr_limit	= KERNEL_DS,		\
57	.step_state	= NULL,			\
58	.align_ctl	= 0,			\
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
80void arch_release_thread_info(struct thread_info *info);
81
82/* How to get the thread information struct from C. */
83register unsigned long stack_pointer __asm__("sp");
84
85#define current_thread_info() \
86  ((struct thread_info *)(stack_pointer & -THREAD_SIZE))
87
88/* Sit on a nap instruction until interrupted. */
89extern void smp_nap(void);
90
91/* Enable interrupts racelessly and nap forever: helper for arch_cpu_idle(). */
92extern void _cpu_idle(void);
93
94#else /* __ASSEMBLY__ */
95
96/*
97 * How to get the thread information struct from assembly.
98 * Note that we use different macros since different architectures
99 * have different semantics in their "mm" instruction and we would
100 * like to guarantee that the macro expands to exactly one instruction.
101 */
102#ifdef __tilegx__
103#define EXTRACT_THREAD_INFO(reg) mm reg, zero, LOG2_THREAD_SIZE, 63
104#else
105#define GET_THREAD_INFO(reg) mm reg, sp, zero, LOG2_THREAD_SIZE, 31
106#endif
107
108#endif /* !__ASSEMBLY__ */
109
110/*
111 * Thread information flags that various assembly files may need to access.
112 * Keep flags accessed frequently in low bits, particular since it makes
113 * it easier to build constants in assembly.
114 */
115#define TIF_SIGPENDING		0	/* signal pending */
116#define TIF_NEED_RESCHED	1	/* rescheduling necessary */
117#define TIF_SINGLESTEP		2	/* restore singlestep on return to
118					   user mode */
119#define TIF_ASYNC_TLB		3	/* got an async TLB fault in kernel */
120#define TIF_SYSCALL_TRACE	4	/* syscall trace active */
121#define TIF_SYSCALL_AUDIT	5	/* syscall auditing active */
122#define TIF_SECCOMP		6	/* secure computing */
123#define TIF_MEMDIE		7	/* OOM killer at work */
124#define TIF_NOTIFY_RESUME	8	/* callback before returning to user */
125#define TIF_SYSCALL_TRACEPOINT	9	/* syscall tracepoint instrumentation */
126#define TIF_POLLING_NRFLAG	10	/* idle is polling for TIF_NEED_RESCHED */
127#define TIF_NOHZ		11	/* in adaptive nohz mode */
128
129#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
130#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
131#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
132#define _TIF_ASYNC_TLB		(1<<TIF_ASYNC_TLB)
133#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
134#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
135#define _TIF_SECCOMP		(1<<TIF_SECCOMP)
136#define _TIF_MEMDIE		(1<<TIF_MEMDIE)
137#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
138#define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
139#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
140#define _TIF_NOHZ		(1<<TIF_NOHZ)
141
142/* Work to do on any return to user space. */
143#define _TIF_ALLWORK_MASK \
144	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_SINGLESTEP | \
145	 _TIF_ASYNC_TLB | _TIF_NOTIFY_RESUME | _TIF_NOHZ)
146
147/* Work to do at syscall entry. */
148#define _TIF_SYSCALL_ENTRY_WORK \
149	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
150
151/* Work to do at syscall exit. */
152#define _TIF_SYSCALL_EXIT_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)
153
154/*
155 * Thread-synchronous status.
156 *
157 * This is different from the flags in that nobody else
158 * ever touches our thread-synchronous status, so we don't
159 * have to worry about atomic accesses.
160 */
161#ifdef __tilegx__
162#define TS_COMPAT		0x0001	/* 32-bit compatibility mode */
163#endif
164#define TS_RESTORE_SIGMASK	0x0008	/* restore signal mask in do_signal */
165
166#ifndef __ASSEMBLY__
167#define HAVE_SET_RESTORE_SIGMASK	1
168static inline void set_restore_sigmask(void)
169{
170	struct thread_info *ti = current_thread_info();
171	ti->status |= TS_RESTORE_SIGMASK;
172	WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
173}
174static inline void clear_restore_sigmask(void)
175{
176	current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
177}
178static inline bool test_restore_sigmask(void)
179{
180	return current_thread_info()->status & TS_RESTORE_SIGMASK;
181}
182static inline bool test_and_clear_restore_sigmask(void)
183{
184	struct thread_info *ti = current_thread_info();
185	if (!(ti->status & TS_RESTORE_SIGMASK))
186		return false;
187	ti->status &= ~TS_RESTORE_SIGMASK;
188	return true;
189}
190#endif	/* !__ASSEMBLY__ */
191
192#endif /* _ASM_TILE_THREAD_INFO_H */
193