Completely rework the allocation/management of Rx buffers.

The firmware expects 3KB Rx buffers so we can't just map mbuf clusters
which are only 2KB.  Also it seems that Rx buffers must be aligned on
a 1KB boundary which is not necessary the case with mbuf clusters.
We want to make damn sure the firmware will not DMA anything outside the
mapped Rx buffers.  The size of the Rx buffers is probably configurable
but Intel will refuse to answer to any question regarding the
programmation of the chipset, and a dump of the device registers led to
nowhere.

1 files changed, 99 insertions, 68 deletions

diff --git a/sys/dev/pci/if_wpi.c b/sys/dev/pci/if_wpi.c
index b5a8cd315b8..cb4359551f9 100644
--- a/sys/dev/pci/if_wpi.c
+++ b/sys/dev/pci/if_wpi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_wpi.c,v 1.30 2006/08/20 14:01:07 damien Exp $	*/
+/*	$OpenBSD: if_wpi.c,v 1.31 2006/08/28 19:47:42 damien Exp $	*/
 
 /*-
  * Copyright (c) 2006
@@ -95,6 +95,10 @@ int		wpi_dma_contig_alloc(struct wpi_softc *, struct wpi_dma_info *,
 void		wpi_dma_contig_free(struct wpi_softc *, struct wpi_dma_info *);
 int		wpi_alloc_shared(struct wpi_softc *);
 void		wpi_free_shared(struct wpi_softc *);
+struct		wpi_rbuf *wpi_alloc_rbuf(struct wpi_softc *);
+void		wpi_free_rbuf(caddr_t, u_int, void *);
+int		wpi_alloc_rpool(struct wpi_softc *);
+void		wpi_free_rpool(struct wpi_softc *);
 int		wpi_alloc_rx_ring(struct wpi_softc *, struct wpi_rx_ring *);
 void		wpi_reset_rx_ring(struct wpi_softc *, struct wpi_rx_ring *);
 void		wpi_free_rx_ring(struct wpi_softc *, struct wpi_rx_ring *);
@@ -239,31 +243,36 @@ wpi_attach(struct device *parent, struct device *self, void *aux)
 		return;
 	}
 
+	if ((error = wpi_alloc_rpool(sc)) != 0) {
+		printf(": could not allocate Rx buffers\n");
+		goto fail1;
+	}
+
 	for (ac = 0; ac < 4; ac++) {
 		error = wpi_alloc_tx_ring(sc, &sc->txq[ac], WPI_TX_RING_COUNT,
 		    ac);
 		if (error != 0) {
 			printf(": could not allocate Tx ring %d\n", ac);
-			goto fail1;
+			goto fail2;
 		}
 	}
 
 	error = wpi_alloc_tx_ring(sc, &sc->cmdq, WPI_CMD_RING_COUNT, 4);
 	if (error != 0) {
 		printf(": could not allocate command ring\n");
-		goto fail1;
+		goto fail2;
 	}
 
 	error = wpi_alloc_tx_ring(sc, &sc->svcq, WPI_SVC_RING_COUNT, 5);
 	if (error != 0) {
 		printf(": could not allocate service ring\n");
-		goto fail2;
+		goto fail3;
 	}
 
 	error = wpi_alloc_rx_ring(sc, &sc->rxq);
 	if (error != 0) {
 		printf(": could not allocate Rx ring\n");
-		goto fail3;
+		goto fail4;
 	}
 
 	ic->ic_phytype = IEEE80211_T_OFDM;	/* not only, but not used */
@@ -357,11 +366,12 @@ wpi_attach(struct device *parent, struct device *self, void *aux)
 
 	return;
 
-fail3:	wpi_free_tx_ring(sc, &sc->svcq);
-fail2:	wpi_free_tx_ring(sc, &sc->cmdq);
-fail1:	while (--ac >= 0)
+fail4:	wpi_free_tx_ring(sc, &sc->svcq);
+fail3:	wpi_free_tx_ring(sc, &sc->cmdq);
+fail2:	while (--ac >= 0)
 		wpi_free_tx_ring(sc, &sc->txq[ac]);
-	wpi_free_shared(sc);
+	wpi_free_rpool(sc);
+fail1:	wpi_free_shared(sc);
 }
 
 int
@@ -381,6 +391,7 @@ wpi_detach(struct device *self, int flags)
 	wpi_free_tx_ring(sc, &sc->cmdq);
 	wpi_free_tx_ring(sc, &sc->svcq);
 	wpi_free_rx_ring(sc, &sc->rxq);
+	wpi_free_rpool(sc);
 	wpi_free_shared(sc);
 
 	if (sc->sc_ih != NULL) {
@@ -459,7 +470,8 @@ wpi_dma_contig_alloc(struct wpi_softc *sc, struct wpi_dma_info *dma,
 	bzero(dma->vaddr, size);
 
 	dma->paddr = dma->map->dm_segs[0].ds_addr;
-	*kvap = dma->vaddr;
+	if (kvap != NULL)
+		*kvap = dma->vaddr;
 
 	return 0;
 
@@ -497,7 +509,6 @@ wpi_alloc_shared(struct wpi_softc *sc)
 		printf("%s: could not allocate shared area DMA memory\n",
 		    sc->sc_dev.dv_xname);
 	}
-
 	return error;
 }
 
@@ -507,10 +518,73 @@ wpi_free_shared(struct wpi_softc *sc)
 	wpi_dma_contig_free(sc, &sc->shared_dma);
 }
 
+struct wpi_rbuf *
+wpi_alloc_rbuf(struct wpi_softc *sc)
+{
+	struct wpi_rbuf *rbuf;
+
+	rbuf = SLIST_FIRST(&sc->rxq.freelist);
+	if (rbuf == NULL)
+		return NULL;
+	SLIST_REMOVE_HEAD(&sc->rxq.freelist, next);
+	return rbuf;
+}
+
+/*
+ * This is called automatically by the network stack when the mbuf to which our
+ * Rx buffer is attached is freed.
+ */
+void
+wpi_free_rbuf(caddr_t buf, u_int size, void *arg)
+{
+	struct wpi_rbuf *rbuf = arg;
+	struct wpi_softc *sc = rbuf->sc;
+
+	/* put the buffer back in the free list */
+	SLIST_INSERT_HEAD(&sc->rxq.freelist, rbuf, next);
+}
+
+int
+wpi_alloc_rpool(struct wpi_softc *sc)
+{
+	struct wpi_rx_ring *ring = &sc->rxq;
+	struct wpi_rbuf *rbuf;
+	int i, error;
+
+	/* allocate a big chunk of DMA'able memory.. */
+	error = wpi_dma_contig_alloc(sc, &ring->buf_dma, NULL,
+	    WPI_RBUF_COUNT * WPI_RBUF_SIZE, PAGE_SIZE, BUS_DMA_NOWAIT);
+	if (error != 0) {
+		printf("%s: could not allocate Rx buffers DMA memory\n",
+		    sc->sc_dev.dv_xname);
+		return error;
+	}
+
+	/* ..and split it into 3KB chunks */
+	SLIST_INIT(&ring->freelist);
+	for (i = 0; i < WPI_RBUF_COUNT; i++) {
+		rbuf = &ring->rbuf[i];
+
+		rbuf->sc = sc;	/* backpointer for callbacks */
+		rbuf->vaddr = ring->buf_dma.vaddr + i * WPI_RBUF_SIZE;
+		rbuf->paddr = ring->buf_dma.paddr + i * WPI_RBUF_SIZE;
+
+		SLIST_INSERT_HEAD(&ring->freelist, rbuf, next);
+	}
+	return 0;
+}
+
+void
+wpi_free_rpool(struct wpi_softc *sc)
+{
+	wpi_dma_contig_free(sc, &sc->rxq.buf_dma);
+}
+
 int
 wpi_alloc_rx_ring(struct wpi_softc *sc, struct wpi_rx_ring *ring)
 {
 	struct wpi_rx_data *data;
+	struct wpi_rbuf *rbuf;
 	int i, error;
 
 	ring->cur = 0;
@@ -525,19 +599,11 @@ wpi_alloc_rx_ring(struct wpi_softc *sc, struct wpi_rx_ring *ring)
 	}
 
 	/*
-	 * Allocate Rx buffers.
+	 * Setup Rx buffers.
 	 */
 	for (i = 0; i < WPI_RX_RING_COUNT; i++) {
 		data = &ring->data[i];
 
-		error = bus_dmamap_create(sc->sc_dmat, MCLBYTES, 1, MCLBYTES,
-		    0, BUS_DMA_NOWAIT, &data->map);
-		if (error != 0) {
-			printf("%s: could not create rx buf DMA map\n",
-			    sc->sc_dev.dv_xname);
-			goto fail;
-		}
-
 		MGETHDR(data->m, M_DONTWAIT, MT_DATA);
 		if (data->m == NULL) {
 			printf("%s: could not allocate rx mbuf\n",
@@ -545,27 +611,19 @@ wpi_alloc_rx_ring(struct wpi_softc *sc, struct wpi_rx_ring *ring)
 			error = ENOMEM;
 			goto fail;
 		}
-
-		MCLGET(data->m, M_DONTWAIT);
-		if (!(data->m->m_flags & M_EXT)) {
+		if ((rbuf = wpi_alloc_rbuf(sc)) == NULL) {
 			m_freem(data->m);
 			data->m = NULL;
-			printf("%s: could not allocate rx mbuf cluster\n",
+			printf("%s: could not allocate rx buffer\n",
 			    sc->sc_dev.dv_xname);
 			error = ENOMEM;
 			goto fail;
 		}
+		/* attach Rx buffer to mbuf */
+		MEXTADD(data->m, rbuf->vaddr, WPI_RBUF_SIZE, 0, wpi_free_rbuf,
+		    rbuf);
 
-		error = bus_dmamap_load(sc->sc_dmat, data->map,
-		    mtod(data->m, void *), MCLBYTES, NULL, BUS_DMA_NOWAIT |
-		    BUS_DMA_READ);
-		if (error != 0) {
-			printf("%s: could not load rx buf DMA map\n",
-			    sc->sc_dev.dv_xname);
-			goto fail;
-		}
-
-		ring->desc[i] = htole32(data->map->dm_segs[0].ds_addr);
+		ring->desc[i] = htole32(rbuf->paddr);
 	}
 
 	return 0;
@@ -599,19 +657,13 @@ wpi_reset_rx_ring(struct wpi_softc *sc, struct wpi_rx_ring *ring)
 void
 wpi_free_rx_ring(struct wpi_softc *sc, struct wpi_rx_ring *ring)
 {
-	struct wpi_rx_data *data;
 	int i;
 
 	wpi_dma_contig_free(sc, &ring->desc_dma);
 
 	for (i = 0; i < WPI_RX_RING_COUNT; i++) {
-		data = &ring->data[i];
-
-		if (data->m != NULL) {
-			bus_dmamap_unload(sc->sc_dmat, data->map);
-			m_freem(data->m);
-		}
-		bus_dmamap_destroy(sc->sc_dmat, data->map);
+		if (ring->data[i].m != NULL)
+			m_freem(ring->data[i].m);
 	}
 }
 
@@ -1066,10 +1118,10 @@ wpi_rx_intr(struct wpi_softc *sc, struct wpi_rx_desc *desc,
 	struct wpi_rx_stat *stat;
 	struct wpi_rx_head *head;
 	struct wpi_rx_tail *tail;
+	struct wpi_rbuf *rbuf;
 	struct ieee80211_frame *wh;
 	struct ieee80211_node *ni;
 	struct mbuf *m, *mnew;
-	int error;
 
 	stat = (struct wpi_rx_stat *)(desc + 1);
 
@@ -1104,38 +1156,19 @@ wpi_rx_intr(struct wpi_softc *sc, struct wpi_rx_desc *desc,
 		ifp->if_ierrors++;
 		return;
 	}
-
-	MCLGET(mnew, M_DONTWAIT);
-	if (!(mnew->m_flags & M_EXT)) {
-		m_freem(mnew);
-		ifp->if_ierrors++;
-		return;
-	}
-
-	bus_dmamap_unload(sc->sc_dmat, data->map);
-
-	error = bus_dmamap_load(sc->sc_dmat, data->map, mtod(mnew, void *),
-	    MCLBYTES, NULL, BUS_DMA_NOWAIT);
-	if (error != 0) {
+	if ((rbuf = wpi_alloc_rbuf(sc)) == NULL) {
 		m_freem(mnew);
-
-		/* try to reload the old mbuf */
-		error = bus_dmamap_load(sc->sc_dmat, data->map,
-		    mtod(data->m, void *), MCLBYTES, NULL, BUS_DMA_NOWAIT);
-		if (error != 0) {
-			/* very unlikely that it will fail... */
-			panic("%s: could not load old rx mbuf",
-			    sc->sc_dev.dv_xname);
-		}
 		ifp->if_ierrors++;
 		return;
 	}
+ 	/* attach Rx buffer to mbuf */
+	MEXTADD(mnew, rbuf->vaddr, WPI_RBUF_SIZE, 0, wpi_free_rbuf, rbuf);
 
 	m = data->m;
 	data->m = mnew;
 
 	/* update Rx descriptor */
-	ring->desc[ring->cur] = htole32(data->map->dm_segs[0].ds_addr);
+	ring->desc[ring->cur] = htole32(rbuf->paddr);
 
 	/* finalize mbuf */
 	m->m_pkthdr.rcvif = ifp;
@@ -1575,7 +1608,6 @@ wpi_tx_data(struct wpi_softc *sc, struct mbuf *m0, struct ieee80211_node *ni,
 			m_freem(m0);
 			return ENOMEM;
 		}
-
 		M_DUP_PKTHDR(mnew, m0);
 		if (m0->m_pkthdr.len > MHLEN) {
 			MCLGET(mnew, M_DONTWAIT);
@@ -2096,7 +2128,6 @@ wpi_scan(struct wpi_softc *sc, uint16_t flags)
 		    sc->sc_dev.dv_xname);
 		return ENOMEM;
 	}
-
 	MCLGET(data->m, M_DONTWAIT);
 	if (!(data->m->m_flags & M_EXT)) {
 		m_freem(data->m);