undo rev 1.10 "implement a zero-copy RX data path".

working with a fixed number of Rx buffers doesn't work well.
fixes problems with blocked incoming traffic.

2 files changed, 53 insertions, 65 deletions

diff --git a/sys/dev/usb/if_uath.c b/sys/dev/usb/if_uath.c
index af15c327ed0..0cb59f2047b 100644
--- a/sys/dev/usb/if_uath.c
+++ b/sys/dev/usb/if_uath.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_uath.c,v 1.29 2007/09/07 19:05:05 damien Exp $	*/
+/*	$OpenBSD: if_uath.c,v 1.30 2007/09/11 19:53:58 damien Exp $	*/
 
 /*-
  * Copyright (c) 2006
@@ -137,7 +137,6 @@ int	uath_alloc_tx_data_list(struct uath_softc *);
 void	uath_free_tx_data_list(struct uath_softc *);
 int	uath_alloc_rx_data_list(struct uath_softc *);
 void	uath_free_rx_data_list(struct uath_softc *);
-void	uath_free_rx_data(caddr_t, u_int, void *);
 int	uath_alloc_tx_cmd_list(struct uath_softc *);
 void	uath_free_tx_cmd_list(struct uath_softc *);
 int	uath_alloc_rx_cmd_list(struct uath_softc *);
@@ -454,15 +453,6 @@ uath_detach(struct device *self, int flags)
 	timeout_del(&sc->scan_to);
 	timeout_del(&sc->stat_to);
 
-	ieee80211_ifdetach(ifp);	/* free all nodes */
-	if_detach(ifp);
-
-	sc->sc_dying = 1;
-	DPRINTF(("reclaiming %d references\n", sc->sc_refcnt));
-	while (sc->sc_refcnt > 0)
-		(void)tsleep(UATH_COND_NOREF(sc), 0, "uathdet", 0);
-	DPRINTF(("all references reclaimed\n"));
-
 	/* abort and free xfers */
 	uath_free_tx_data_list(sc);
 	uath_free_rx_data_list(sc);
@@ -472,6 +462,9 @@ uath_detach(struct device *self, int flags)
 	/* close Tx/Rx pipes */
 	uath_close_pipes(sc);
 
+	ieee80211_ifdetach(ifp);	/* free all nodes */
+	if_detach(ifp);
+
 	splx(s);
 
 	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_udev,
@@ -595,8 +588,7 @@ uath_alloc_rx_data_list(struct uath_softc *sc)
 {
 	int i, error;
 
-	SLIST_INIT(&sc->rx_freelist);
-	for (i = 0; i < UATH_RX_DATA_POOL_COUNT; i++) {
+	for (i = 0; i < UATH_RX_DATA_LIST_COUNT; i++) {
 		struct uath_rx_data *data = &sc->rx_data[i];
 
 		data->sc = sc;	/* backpointer for callbacks */
@@ -608,14 +600,29 @@ uath_alloc_rx_data_list(struct uath_softc *sc)
 			error = ENOMEM;
 			goto fail;
 		}
-		data->buf = usbd_alloc_buffer(data->xfer, sc->rxbufsz);
-		if (data->buf == NULL) {
+		if (usbd_alloc_buffer(data->xfer, sc->rxbufsz) == NULL) {
 			printf("%s: could not allocate xfer buffer\n",
 			    sc->sc_dev.dv_xname);
 			error = ENOMEM;
 			goto fail;
 		}
-		SLIST_INSERT_HEAD(&sc->rx_freelist, data, next);
+
+		MGETHDR(data->m, M_DONTWAIT, MT_DATA);
+		if (data->m == NULL) {
+			printf("%s: could not allocate rx mbuf\n",
+			    sc->sc_dev.dv_xname);
+			error = ENOMEM;
+			goto fail;
+		}
+		MCLGET(data->m, M_DONTWAIT);
+		if (!(data->m->m_flags & M_EXT)) {
+			printf("%s: could not allocate rx mbuf cluster\n",
+			    sc->sc_dev.dv_xname);
+			error = ENOMEM;
+			goto fail;
+		}
+
+		data->buf = mtod(data->m, uint8_t *);
 	}
 	return 0;
 
@@ -631,23 +638,15 @@ uath_free_rx_data_list(struct uath_softc *sc)
 	/* make sure no transfers are pending */
 	usbd_abort_pipe(sc->data_rx_pipe);
 
-	for (i = 0; i < UATH_RX_DATA_POOL_COUNT; i++)
-		if (sc->rx_data[i].xfer != NULL)
-			usbd_free_xfer(sc->rx_data[i].xfer);
-}
-
-void
-uath_free_rx_data(caddr_t buf, u_int size, void *arg)
-{
-	struct uath_rx_data *data = arg;
-	struct uath_softc *sc = data->sc;
+	for (i = 0; i < UATH_RX_DATA_LIST_COUNT; i++) {
+		struct uath_rx_data *data = &sc->rx_data[i];
 
-	/* put the buffer back in the free list */
-	SLIST_INSERT_HEAD(&sc->rx_freelist, data, next);
+		if (data->xfer != NULL)
+			usbd_free_xfer(data->xfer);
 
-	/* release reference to softc */
-	if (--sc->sc_refcnt == 0 && sc->sc_dying)
-		wakeup(UATH_COND_NOREF(sc));
+		if (data->m != NULL)
+			m_freem(data->m);
+	}
 }
 
 int
@@ -1185,9 +1184,8 @@ uath_data_rxeof(usbd_xfer_handle xfer, usbd_private_handle priv,
 	struct ifnet *ifp = &ic->ic_if;
 	struct ieee80211_frame *wh;
 	struct ieee80211_node *ni;
-	struct uath_rx_data *ndata;
 	struct uath_rx_desc *desc;
-	struct mbuf *m;
+	struct mbuf *mnew, *m;
 	uint32_t hdr;
 	int s, len;
 
@@ -1223,24 +1221,24 @@ uath_data_rxeof(usbd_xfer_handle xfer, usbd_private_handle priv,
 
 	/* there's probably a "bad CRC" flag somewhere in the descriptor.. */
 
-	MGETHDR(m, M_DONTWAIT, MT_DATA);
-	if (m == NULL) {
+	MGETHDR(mnew, M_DONTWAIT, MT_DATA);
+	if (mnew == NULL) {
+		printf("%s: could not allocate rx mbuf\n",
+		    sc->sc_dev.dv_xname);
 		ifp->if_ierrors++;
 		goto skip;
 	}
-
-	/* grab a new Rx buffer */
-	ndata = SLIST_FIRST(&sc->rx_freelist);
-	if (ndata == NULL) {
-		printf("%s: could not allocate Rx buffer\n",
+	MCLGET(mnew, M_DONTWAIT);
+	if (!(mnew->m_flags & M_EXT)) {
+		printf("%s: could not allocate rx mbuf cluster\n",
 		    sc->sc_dev.dv_xname);
-		m_freem(m);
+		m_freem(mnew);
 		ifp->if_ierrors++;
 		goto skip;
 	}
-	SLIST_REMOVE_HEAD(&sc->rx_freelist, next);
 
-	MEXTADD(m, data->buf, sc->rxbufsz, 0, uath_free_rx_data, data);
+	m = data->m;
+	data->m = mnew;
 
 	/* finalize mbuf */
 	m->m_pkthdr.rcvif = ifp;
@@ -1248,7 +1246,7 @@ uath_data_rxeof(usbd_xfer_handle xfer, usbd_private_handle priv,
 	m->m_pkthdr.len = m->m_len = betoh32(desc->len) -
 	    sizeof (struct uath_rx_desc) - IEEE80211_CRC_LEN;
 
-	data = ndata;
+	data->buf = mtod(data->m, uint8_t *);
 
 	wh = mtod(m, struct ieee80211_frame *);
 	if ((wh->i_fc[1] & IEEE80211_FC1_WEP) &&
@@ -1288,7 +1286,6 @@ uath_data_rxeof(usbd_xfer_handle xfer, usbd_private_handle priv,
 #endif
 
 	s = splnet();
-	sc->sc_refcnt++;
 	ni = ieee80211_find_rxnode(ic, wh);
 	ieee80211_input(ifp, m, ni, (int)betoh32(desc->rssi), 0);
 
@@ -1297,9 +1294,8 @@ uath_data_rxeof(usbd_xfer_handle xfer, usbd_private_handle priv,
 	splx(s);
 
 skip:	/* setup a new transfer */
-	usbd_setup_xfer(data->xfer, sc->data_rx_pipe, data, data->buf,
-	    sc->rxbufsz, USBD_SHORT_XFER_OK | USBD_NO_COPY, USBD_NO_TIMEOUT,
-	    uath_data_rxeof);
+	usbd_setup_xfer(xfer, sc->data_rx_pipe, data, data->buf, sc->rxbufsz,
+	    USBD_SHORT_XFER_OK, USBD_NO_TIMEOUT, uath_data_rxeof);
 	(void)usbd_transfer(data->xfer);
 }
 
@@ -1897,18 +1893,17 @@ uath_init(struct ifnet *ifp)
 	 * Queue Rx data xfers.
 	 */
 	for (i = 0; i < UATH_RX_DATA_LIST_COUNT; i++) {
-		struct uath_rx_data *data = SLIST_FIRST(&sc->rx_freelist);
+		struct uath_rx_data *data = &sc->rx_data[i];
 
 		usbd_setup_xfer(data->xfer, sc->data_rx_pipe, data, data->buf,
-		    sc->rxbufsz, USBD_SHORT_XFER_OK | USBD_NO_COPY,
-		    USBD_NO_TIMEOUT, uath_data_rxeof);
+		    sc->rxbufsz, USBD_SHORT_XFER_OK, USBD_NO_TIMEOUT,
+		    uath_data_rxeof);
 		error = usbd_transfer(data->xfer);
 		if (error != USBD_IN_PROGRESS && error != 0) {
 			printf("%s: could not queue Rx transfer\n",
 			    sc->sc_dev.dv_xname);
 			goto fail;
 		}
-		SLIST_REMOVE_HEAD(&sc->rx_freelist, next);
 	}
 
 	error = uath_cmd_read(sc, UATH_CMD_07, 0, NULL, &val,
diff --git a/sys/dev/usb/if_uathvar.h b/sys/dev/usb/if_uathvar.h
index 0d6a1271e9d..5ae648c724c 100644
--- a/sys/dev/usb/if_uathvar.h
+++ b/sys/dev/usb/if_uathvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_uathvar.h,v 1.5 2007/06/06 19:25:49 mk Exp $	*/
+/*	$OpenBSD: if_uathvar.h,v 1.6 2007/09/11 19:53:58 damien Exp $	*/
 
 /*-
  * Copyright (c) 2006
@@ -24,8 +24,6 @@
 #define UATH_RX_DATA_LIST_COUNT	1	/* 128 */
 #define UATH_RX_CMD_LIST_COUNT	1	/* 30 */
 
-#define UATH_RX_DATA_POOL_COUNT	(UATH_RX_DATA_LIST_COUNT + 24)
-
 #define UATH_DATA_TIMEOUT	10000
 #define UATH_CMD_TIMEOUT	1000
 
@@ -61,10 +59,10 @@ struct uath_tx_data {
 };
 
 struct uath_rx_data {
-	struct uath_softc		*sc;
-	usbd_xfer_handle		xfer;
-	uint8_t				*buf;
-	SLIST_ENTRY(uath_rx_data)	next;
+	struct uath_softc	*sc;
+	usbd_xfer_handle	xfer;
+	uint8_t			*buf;
+	struct mbuf		*m;
 };
 
 struct uath_tx_cmd {
@@ -92,7 +90,6 @@ struct uath_wme_settings {
 
 /* condvars */
 #define UATH_COND_INIT(sc)	((caddr_t)sc + 1)
-#define UATH_COND_NOREF(sc)	((caddr_t)sc + 2)
 
 /* flags for sending firmware commands */
 #define UATH_CMD_FLAG_ASYNC	(1 << 0)
@@ -106,16 +103,12 @@ struct uath_softc {
 					    enum ieee80211_state, int);
 
 	struct uath_tx_data		tx_data[UATH_TX_DATA_LIST_COUNT];
-	struct uath_rx_data		rx_data[UATH_RX_DATA_POOL_COUNT];
+	struct uath_rx_data		rx_data[UATH_RX_DATA_LIST_COUNT];
 
 	struct uath_tx_cmd		tx_cmd[UATH_TX_CMD_LIST_COUNT];
 	struct uath_rx_cmd		rx_cmd[UATH_RX_CMD_LIST_COUNT];
 
-	SLIST_HEAD(, uath_rx_data)	rx_freelist;
-
 	int				sc_flags;
-	int				sc_dying;
-	int				sc_refcnt;
 
 	int				data_idx;
 	int				cmd_idx;