diff options
Diffstat (limited to 'include/asm-alpha')
| -rw-r--r-- | include/asm-alpha/futex.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/include/asm-alpha/futex.h b/include/asm-alpha/futex.h new file mode 100644 index 00000000000..2cac5ecd9d0 --- /dev/null +++ b/include/asm-alpha/futex.h @@ -0,0 +1,53 @@ +#ifndef _ASM_FUTEX_H +#define _ASM_FUTEX_H + +#ifdef __KERNEL__ + +#include <linux/futex.h> +#include <asm/errno.h> +#include <asm/uaccess.h> + +static inline int +futex_atomic_op_inuser (int encoded_op, int __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 = 0, ret, tem; + if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) + oparg = 1 << oparg; + + if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) + return -EFAULT; + + inc_preempt_count(); + + switch (op) { + case FUTEX_OP_SET: + case FUTEX_OP_ADD: + case FUTEX_OP_OR: + case FUTEX_OP_ANDN: + case FUTEX_OP_XOR: + default: + ret = -ENOSYS; + } + + dec_preempt_count(); + + if (!ret) { + 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; +} + +#endif +#endif |