On Mon, Sep 8, 2014 at 5:22 PM, Ley Foon Tan <lftan@xxxxxxxxxx> wrote:
> Follow m68k futex implementation for !CONFIG_SMP.
>
> Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx>
> ---
> 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
>
Hi Arnd
Are you okay with this generic futex in asm-generic?
Regards
Ley Foon
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