thread_info.h

Go to the documentation of this file.

/* thread_info.h: PowerPC low-level thread information
 * adapted from the i386 version by Paul Mackerras
 *
 * Copyright (C) 2002  David Howells ([email protected])
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 */

#ifndef _ASM_POWERPC_THREAD_INFO_H
#define _ASM_POWERPC_THREAD_INFO_H

#ifdef __KERNEL__

/* We have 8k stacks on ppc32 and 16k on ppc64 */

#if defined(CONFIG_PPC64)
#define THREAD_SHIFT        14
#elif defined(CONFIG_PPC_256K_PAGES)
#define THREAD_SHIFT        15
#else
#define THREAD_SHIFT        13
#endif

#define THREAD_SIZE     (1 << THREAD_SHIFT)

#ifdef CONFIG_PPC64
#define CURRENT_THREAD_INFO(dest, sp)   clrrdi dest, sp, THREAD_SHIFT
#else
#define CURRENT_THREAD_INFO(dest, sp)   rlwinm dest, sp, 0, 0, 31-THREAD_SHIFT
#endif

#ifndef __ASSEMBLY__
#include <linux/cache.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <linux/stringify.h>

/*
 * low level task data.
 */
struct thread_info {
    struct task_struct *task;       /* main task structure */
    struct exec_domain *exec_domain;    /* execution domain */
    int     cpu;            /* cpu we're on */
    int     preempt_count;      /* 0 => preemptable,
                           <0 => BUG */
    struct restart_block restart_block;
    unsigned long   local_flags;        /* private flags for thread */

    /* low level flags - has atomic operations done on it */
    unsigned long   flags ____cacheline_aligned_in_smp;
};

/*
 * macros/functions for gaining access to the thread information structure
 */
#define INIT_THREAD_INFO(tsk)           \
{                       \
    .task =     &tsk,           \
    .exec_domain =  &default_exec_domain,   \
    .cpu =      0,          \
    .preempt_count = INIT_PREEMPT_COUNT,    \
    .restart_block = {          \
        .fn = do_no_restart_syscall,    \
    },                  \
    .flags =    0,          \
}

#define init_thread_info    (init_thread_union.thread_info)
#define init_stack      (init_thread_union.stack)

#define THREAD_SIZE_ORDER   (THREAD_SHIFT - PAGE_SHIFT)

/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
    register unsigned long sp asm("r1");

    /* gcc4, at least, is smart enough to turn this into a single
     * rlwinm for ppc32 and clrrdi for ppc64 */
    return (struct thread_info *)(sp & ~(THREAD_SIZE-1));
}

#endif /* __ASSEMBLY__ */

#define PREEMPT_ACTIVE      0x10000000

/*
 * thread information flag bit numbers
 */
#define TIF_SYSCALL_TRACE   0   /* syscall trace active */
#define TIF_SIGPENDING      1   /* signal pending */
#define TIF_NEED_RESCHED    2   /* rescheduling necessary */
#define TIF_POLLING_NRFLAG  3   /* true if poll_idle() is polling
                       TIF_NEED_RESCHED */
#define TIF_32BIT       4   /* 32 bit binary */
#define TIF_PERFMON_WORK    5   /* work for pfm_handle_work() */
#define TIF_PERFMON_CTXSW   6   /* perfmon needs ctxsw calls */
#define TIF_SYSCALL_AUDIT   7   /* syscall auditing active */
#define TIF_SINGLESTEP      8   /* singlestepping active */
#define TIF_MEMDIE      9   /* is terminating due to OOM killer */
#define TIF_SECCOMP     10  /* secure computing */
#define TIF_RESTOREALL      11  /* Restore all regs (implies NOERROR) */
#define TIF_NOERROR     12  /* Force successful syscall return */
#define TIF_NOTIFY_RESUME   13  /* callback before returning to user */
#define TIF_UPROBE      14  /* breakpointed or single-stepping */
#define TIF_SYSCALL_TRACEPOINT  15  /* syscall tracepoint instrumentation */
#define TIF_EMULATE_STACK_STORE 16  /* Is an instruction emulation
                        for stack store? */

/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE  (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING     (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED   (1<<TIF_NEED_RESCHED)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_32BIT      (1<<TIF_32BIT)
#define _TIF_PERFMON_WORK   (1<<TIF_PERFMON_WORK)
#define _TIF_PERFMON_CTXSW  (1<<TIF_PERFMON_CTXSW)
#define _TIF_SYSCALL_AUDIT  (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SINGLESTEP     (1<<TIF_SINGLESTEP)
#define _TIF_SECCOMP        (1<<TIF_SECCOMP)
#define _TIF_RESTOREALL     (1<<TIF_RESTOREALL)
#define _TIF_NOERROR        (1<<TIF_NOERROR)
#define _TIF_NOTIFY_RESUME  (1<<TIF_NOTIFY_RESUME)
#define _TIF_UPROBE     (1<<TIF_UPROBE)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_EMULATE_STACK_STORE    (1<<TIF_EMULATE_STACK_STORE)
#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
                 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT)

#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
                 _TIF_NOTIFY_RESUME | _TIF_UPROBE)
#define _TIF_PERSYSCALL_MASK    (_TIF_RESTOREALL|_TIF_NOERROR)

/* Bits in local_flags */
/* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
#define TLF_NAPPING     0   /* idle thread enabled NAP mode */
#define TLF_SLEEPING        1   /* suspend code enabled SLEEP mode */
#define TLF_RESTORE_SIGMASK 2   /* Restore signal mask in do_signal */
#define TLF_LAZY_MMU        3   /* tlb_batch is active */
#define TLF_RUNLATCH        4   /* Is the runlatch enabled? */

#define _TLF_NAPPING        (1 << TLF_NAPPING)
#define _TLF_SLEEPING       (1 << TLF_SLEEPING)
#define _TLF_RESTORE_SIGMASK    (1 << TLF_RESTORE_SIGMASK)
#define _TLF_LAZY_MMU       (1 << TLF_LAZY_MMU)
#define _TLF_RUNLATCH       (1 << TLF_RUNLATCH)

#ifndef __ASSEMBLY__
#define HAVE_SET_RESTORE_SIGMASK    1
static inline void set_restore_sigmask(void)
{
    struct thread_info *ti = current_thread_info();
    ti->local_flags |= _TLF_RESTORE_SIGMASK;
    WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
}
static inline void clear_restore_sigmask(void)
{
    current_thread_info()->local_flags &= ~_TLF_RESTORE_SIGMASK;
}
static inline bool test_restore_sigmask(void)
{
    return current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK;
}
static inline bool test_and_clear_restore_sigmask(void)
{
    struct thread_info *ti = current_thread_info();
    if (!(ti->local_flags & _TLF_RESTORE_SIGMASK))
        return false;
    ti->local_flags &= ~_TLF_RESTORE_SIGMASK;
    return true;
}

static inline bool test_thread_local_flags(unsigned int flags)
{
    struct thread_info *ti = current_thread_info();
    return (ti->local_flags & flags) != 0;
}

#ifdef CONFIG_PPC64
#define is_32bit_task() (test_thread_flag(TIF_32BIT))
#else
#define is_32bit_task() (1)
#endif

#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)

#endif  /* !__ASSEMBLY__ */

#endif /* __KERNEL__ */

#endif /* _ASM_POWERPC_THREAD_INFO_H */