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    Subject[PATCH v5 01/29] asm-generic: add generic futex for !CONFIG_SMP
    Date
    Follow m68k futex implementation for !CONFIG_SMP.

    Signed-off-by: Ley Foon Tan <lftan@altera.com>
    Acked-by: Arnd Bergmann <arnd@arndb.de>
    ---
    include/asm-generic/futex.h | 82 +++++++++++++++++++++++++++++++++++++++++++++
    1 file changed, 82 insertions(+)

    diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h
    index 01f227e..f5650a5 100644
    --- a/include/asm-generic/futex.h
    +++ b/include/asm-generic/futex.h
    @@ -5,6 +5,87 @@
    #include <linux/uaccess.h>
    #include <asm/errno.h>

    +#ifndef CONFIG_SMP
    +static inline int
    +futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
    +{
    + int op = (encoded_op >> 28) & 7;
    + int cmp = (encoded_op >> 24) & 15;
    + int oparg = (encoded_op << 8) >> 20;
    + int cmparg = (encoded_op << 20) >> 20;
    + int oldval, ret;
    + u32 tmp;
    +
    + if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
    + oparg = 1 << oparg;
    +
    + pagefault_disable(); /* implies preempt_disable() */
    +
    + ret = -EFAULT;
    + if (unlikely(get_user(oldval, uaddr) != 0))
    + goto out_pagefault_enable;
    +
    + ret = 0;
    + tmp = oldval;
    +
    + switch (op) {
    + case FUTEX_OP_SET:
    + tmp = oparg;
    + break;
    + case FUTEX_OP_ADD:
    + tmp += oparg;
    + break;
    + case FUTEX_OP_OR:
    + tmp |= oparg;
    + break;
    + case FUTEX_OP_ANDN:
    + tmp &= ~oparg;
    + break;
    + case FUTEX_OP_XOR:
    + tmp ^= oparg;
    + break;
    + default:
    + ret = -ENOSYS;
    + }
    +
    + if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0))
    + ret = -EFAULT;
    +
    +out_pagefault_enable:
    + pagefault_enable(); /* subsumes preempt_enable() */
    +
    + if (ret == 0) {
    + switch (cmp) {
    + case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
    + case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
    + case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
    + case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
    + case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
    + case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
    + default: ret = -ENOSYS;
    + }
    + }
    + return ret;
    +}
    +
    +static inline int
    +futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
    + u32 oldval, u32 newval)
    +{
    + u32 val;
    +
    + if (unlikely(get_user(val, uaddr) != 0))
    + return -EFAULT;
    +
    + if (val == oldval && unlikely(put_user(newval, uaddr) != 0))
    + return -EFAULT;
    +
    + *uval = val;
    +
    + return 0;
    +}
    +
    +#else
    static inline int
    futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
    {
    @@ -54,4 +135,5 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
    return -ENOSYS;
    }

    +#endif /* CONFIG_SMP */
    #endif
    --
    1.8.2.1


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