text: /*
   * Copyright (C) 2002  David Howells (dhowells@redhat.com)
   * Copyright 2010 Tilera Corporation. All Rights Reserved.
   *
   *   This program is free software; you can redistribute it and/or
   *   modify it under the terms of the GNU General Public License
   *   as published by the Free Software Foundation, version 2.
   *
   *   This program is distributed in the hope that it will be useful, but
   *   WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
   *   NON INFRINGEMENT.  See the GNU General Public License for
   *   more details.
   */
  
  #ifndef _ASM_TILE_THREAD_INFO_H
  #define _ASM_TILE_THREAD_INFO_H
  
  #include <asm/processor.h>
  #include <asm/page.h>
  #ifndef __ASSEMBLY__
  
  /*
   * Low level task data that assembly code needs immediate access to.
   * The structure is placed at the bottom of the supervisor stack.
   */
  struct thread_info {
  	struct task_struct	*task;		/* main task structure */
  	unsigned long		flags;		/* low level flags */
  	unsigned long		status;		/* thread-synchronous flags */
  	__u32			homecache_cpu;	/* CPU we are homecached on */
  	__u32			cpu;		/* current CPU */
  	int			preempt_count;	/* 0 => preemptable,
  						   <0 => BUG */
  
  	mm_segment_t		addr_limit;	/* thread address space
  						   (KERNEL_DS or USER_DS) */
  	struct single_step_state *step_state;	/* single step state
  						   (if non-zero) */
  	int			align_ctl;	/* controls unaligned access */
  #ifdef __tilegx__
  	unsigned long		unalign_jit_tmp[4]; /* temp r0..r3 storage */
  	void __user		*unalign_jit_base; /* unalign fixup JIT base */
  #endif
  	bool in_backtrace;			/* currently doing backtrace? */
  };
  
  /*
   * macros/functions for gaining access to the thread information structure.
   */
  #define INIT_THREAD_INFO(tsk)			\
  {						\
  	.task		= &tsk,			\
  	.flags		= 0,			\
  	.cpu		= 0,			\
  	.preempt_count	= INIT_PREEMPT_COUNT,	\
  	.addr_limit	= KERNEL_DS,		\
  	.step_state	= NULL,			\
  	.align_ctl	= 0,			\
  }
  
  #define init_thread_info	(init_thread_union.thread_info)
  #define init_stack		(init_thread_union.stack)
  
  #endif /* !__ASSEMBLY__ */
  
  #if PAGE_SIZE < 8192
  #define THREAD_SIZE_ORDER (13 - PAGE_SHIFT)
  #else
  #define THREAD_SIZE_ORDER (0)
  #endif
  #define THREAD_SIZE_PAGES (1 << THREAD_SIZE_ORDER)
  
  #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
  #define LOG2_THREAD_SIZE (PAGE_SHIFT + THREAD_SIZE_ORDER)
  
  #define STACK_WARN             (THREAD_SIZE/8)
  
  #ifndef __ASSEMBLY__
  
  void arch_release_thread_stack(unsigned long *stack);
  
  /* How to get the thread information struct from C. */
  register unsigned long stack_pointer __asm__("sp");
  
  #define current_thread_info() \
    ((struct thread_info *)(stack_pointer & -THREAD_SIZE))
  
  /* Sit on a nap instruction until interrupted. */
  extern void smp_nap(void);
  
  /* Enable interrupts racelessly and nap forever: helper for arch_cpu_idle(). */
  extern void _cpu_idle(void);
  
  #else /* __ASSEMBLY__ */
  
  /*
   * How to get the thread information struct from assembly.
   * Note that we use different macros since different architectures
   * have different semantics in their "mm" instruction and we would
   * like to guarantee that the macro expands to exactly one instruction.
   */
  #ifdef __tilegx__
  #define EXTRACT_THREAD_INFO(reg) mm reg, zero, LOG2_THREAD_SIZE, 63
  #else
  #define GET_THREAD_INFO(reg) mm reg, sp, zero, LOG2_THREAD_SIZE, 31
  #endif
  
  #endif /* !__ASSEMBLY__ */
  
  /*
   * Thread information flags that various assembly files may need to access.
   * Keep flags accessed frequently in low bits, particular since it makes
   * it easier to build constants in assembly.
   */
  #define TIF_SIGPENDING		0	/* signal pending */
  #define TIF_NEED_RESCHED	1	/* rescheduling necessary */
  #define TIF_SINGLESTEP		2	/* restore singlestep on return to
  					   user mode */
  #define TIF_ASYNC_TLB		3	/* got an async TLB fault in kernel */
  #define TIF_SYSCALL_TRACE	4	/* syscall trace active */
  #define TIF_SYSCALL_AUDIT	5	/* syscall auditing active */
  #define TIF_SECCOMP		6	/* secure computing */
  #define TIF_MEMDIE		7	/* OOM killer at work */
  #define TIF_NOTIFY_RESUME	8	/* callback before returning to user */
  #define TIF_SYSCALL_TRACEPOINT	9	/* syscall tracepoint instrumentation */
  #define TIF_POLLING_NRFLAG	10	/* idle is polling for TIF_NEED_RESCHED */
  #define TIF_NOHZ		11	/* in adaptive nohz mode */
  
  #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
  #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
  #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
  #define _TIF_ASYNC_TLB		(1<<TIF_ASYNC_TLB)
  #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
  #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
  #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
  #define _TIF_MEMDIE		(1<<TIF_MEMDIE)
  #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
  #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
  #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
  #define _TIF_NOHZ		(1<<TIF_NOHZ)
  
  /* Work to do as we loop to exit to user space. */
  #define _TIF_WORK_MASK \
  	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
  	 _TIF_ASYNC_TLB | _TIF_NOTIFY_RESUME)
  
  /* Work to do on any return to user space. */
  #define _TIF_ALLWORK_MASK \
  	(_TIF_WORK_MASK | _TIF_SINGLESTEP | _TIF_NOHZ)
  
  /* Work to do at syscall entry. */
  #define _TIF_SYSCALL_ENTRY_WORK \
  	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_NOHZ)
  
  /* Work to do at syscall exit. */
  #define _TIF_SYSCALL_EXIT_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)
  
  /*
   * Thread-synchronous status.
   *
   * This is different from the flags in that nobody else
   * ever touches our thread-synchronous status, so we don't
   * have to worry about atomic accesses.
   */
  #ifdef __tilegx__
  #define TS_COMPAT		0x0001	/* 32-bit compatibility mode */
  #endif
  
  #endif /* _ASM_TILE_THREAD_INFO_H */
  