XHCI_GET_CTX
slot = XHCI_GET_CTX(sc, xhci_dev_ctx, ctx_slot,
input = XHCI_GET_CTX(sc, xhci_input_dev_ctx, ctx_input,
slot = XHCI_GET_CTX(sc, xhci_input_dev_ctx, ctx_slot, buf_inp.buffer);
endp = XHCI_GET_CTX(sc, xhci_input_dev_ctx, ctx_ep[epno - 1],
slot = XHCI_GET_CTX(sc, xhci_input_dev_ctx, ctx_slot, buf_inp.buffer);
endp = XHCI_GET_CTX(sc, xhci_dev_ctx, ctx_ep[epno - 1],