+ return result & RIO_PORT_N_ERR_STS_PORT_OK;
+}
+
+/**
+ * rio_lock_device - Acquires host device lock for specified device
+ * @port: Master port to send transaction
+ * @destid: Destination ID for device/switch
+ * @hopcount: Hopcount to reach switch
+ * @wait_ms: Max wait time in msec (0 = no timeout)
+ *
+ * Attepts to acquire host device lock for specified device
+ * Returns 0 if device lock acquired or EINVAL if timeout expires.
+ */
+static int
+rio_lock_device(struct rio_mport *port, u16 destid, u8 hopcount, int wait_ms)
+{
+ u32 result;
+ int tcnt = 0;
+
+ /* Attempt to acquire device lock */
+ rio_mport_write_config_32(port, destid, hopcount,
+ RIO_HOST_DID_LOCK_CSR, port->host_deviceid);
+ rio_mport_read_config_32(port, destid, hopcount,
+ RIO_HOST_DID_LOCK_CSR, &result);
+
+ while (result != port->host_deviceid) {
+ if (wait_ms != 0 && tcnt == wait_ms) {
+ pr_debug("RIO: timeout when locking device %x:%x\n",
+ destid, hopcount);
+ return -EINVAL;
+ }
+
+ /* Delay a bit */
+ mdelay(1);
+ tcnt++;
+ /* Try to acquire device lock again */
+ rio_mport_write_config_32(port, destid,
+ hopcount,
+ RIO_HOST_DID_LOCK_CSR,
+ port->host_deviceid);
+ rio_mport_read_config_32(port, destid,
+ hopcount,
+ RIO_HOST_DID_LOCK_CSR, &result);
+ }
+
+ return 0;
+}
+
+/**
+ * rio_unlock_device - Releases host device lock for specified device
+ * @port: Master port to send transaction
+ * @destid: Destination ID for device/switch
+ * @hopcount: Hopcount to reach switch
+ *
+ * Returns 0 if device lock released or EINVAL if fails.
+ */
+static int
+rio_unlock_device(struct rio_mport *port, u16 destid, u8 hopcount)
+{
+ u32 result;
+
+ /* Release device lock */
+ rio_mport_write_config_32(port, destid,
+ hopcount,
+ RIO_HOST_DID_LOCK_CSR,
+ port->host_deviceid);
+ rio_mport_read_config_32(port, destid, hopcount,
+ RIO_HOST_DID_LOCK_CSR, &result);
+ if ((result & 0xffff) != 0xffff) {
+ pr_debug("RIO: badness when releasing device lock %x:%x\n",
+ destid, hopcount);
+ return -EINVAL;
+ }
+
+ return 0;