/arch/tile/include/asm/thread_info.h

  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	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. */
 81register 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
 87extern struct thread_info *alloc_thread_info_node(struct task_struct *task, int node);
 88extern void free_thread_info(struct thread_info *info);
 89
 90/* Sit on a nap instruction until interrupted. */
 91extern void smp_nap(void);
 92
 93/* Enable interrupts racelessly and nap forever: helper for cpu_idle(). */
 94extern void _cpu_idle(void);
 95
 96/* Switch boot idle thread to a freshly-allocated stack and free old stack. */
 97extern 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/* how to get the thread information struct from ASM */
104#ifdef __tilegx__
105#define GET_THREAD_INFO(reg) move reg, sp; mm reg, zero, LOG2_THREAD_SIZE, 63
106#else
107#define GET_THREAD_INFO(reg) mm reg, sp, zero, LOG2_THREAD_SIZE, 31
108#endif
109
110#endif /* !__ASSEMBLY__ */
111
112#define PREEMPT_ACTIVE		0x10000000
113
114/*
115 * Thread information flags that various assembly files may need to access.
116 * Keep flags accessed frequently in low bits, particular since it makes
117 * it easier to build constants in assembly.
118 */
119#define TIF_SIGPENDING		0	/* signal pending */
120#define TIF_NEED_RESCHED	1	/* rescheduling necessary */
121#define TIF_SINGLESTEP		2	/* restore singlestep on return to
122					   user mode */
123#define TIF_ASYNC_TLB		3	/* got an async TLB fault in kernel */
124#define TIF_SYSCALL_TRACE	4	/* syscall trace active */
125#define TIF_SYSCALL_AUDIT	5	/* syscall auditing active */
126#define TIF_SECCOMP		6	/* secure computing */
127#define TIF_MEMDIE		7	/* OOM killer at work */
128#define TIF_NOTIFY_RESUME	8	/* callback before returning to user */
129
130#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
131#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
132#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
133#define _TIF_ASYNC_TLB		(1<<TIF_ASYNC_TLB)
134#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
135#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
136#define _TIF_SECCOMP		(1<<TIF_SECCOMP)
137#define _TIF_MEMDIE		(1<<TIF_MEMDIE)
138#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
139
140/* Work to do on any return to user space. */
141#define _TIF_ALLWORK_MASK \
142  (_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SINGLESTEP|\
143   _TIF_ASYNC_TLB|_TIF_NOTIFY_RESUME)
144
145/*
146 * Thread-synchronous status.
147 *
148 * This is different from the flags in that nobody else
149 * ever touches our thread-synchronous status, so we don't
150 * have to worry about atomic accesses.
151 */
152#ifdef __tilegx__
153#define TS_COMPAT		0x0001	/* 32-bit compatibility mode */
154#endif
155#define TS_POLLING		0x0004	/* in idle loop but not sleeping */
156#define TS_RESTORE_SIGMASK	0x0008	/* restore signal mask in do_signal */
157
158#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
159
160#ifndef __ASSEMBLY__
161#define HAVE_SET_RESTORE_SIGMASK	1
162static inline void set_restore_sigmask(void)
163{
164	struct thread_info *ti = current_thread_info();
165	ti->status |= TS_RESTORE_SIGMASK;
166	set_bit(TIF_SIGPENDING, &ti->flags);
167}
168#endif	/* !__ASSEMBLY__ */
169
170#endif /* _ASM_TILE_THREAD_INFO_H */