1 files changed, 871 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c
new file mode 100644
index 000000000000..f29c294413cf
--- /dev/null
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -0,0 +1,871 @@
+/*
+ * Copyright (c) 2012 Qualcomm Atheros, Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/hardirq.h>
+#include <net/ieee80211_radiotap.h>
+#include <linux/if_arp.h>
+#include <linux/moduleparam.h>
+
+#include "wil6210.h"
+#include "wmi.h"
+#include "txrx.h"
+
+static bool rtap_include_phy_info;
+module_param(rtap_include_phy_info, bool, S_IRUGO);
+MODULE_PARM_DESC(rtap_include_phy_info,
+		 " Include PHY info in the radiotap header, default - no");
+
+static inline int wil_vring_is_empty(struct vring *vring)
+{
+	return vring->swhead == vring->swtail;
+}
+
+static inline u32 wil_vring_next_tail(struct vring *vring)
+{
+	return (vring->swtail + 1) % vring->size;
+}
+
+static inline void wil_vring_advance_head(struct vring *vring, int n)
+{
+	vring->swhead = (vring->swhead + n) % vring->size;
+}
+
+static inline int wil_vring_is_full(struct vring *vring)
+{
+	return wil_vring_next_tail(vring) == vring->swhead;
+}
+/*
+ * Available space in Tx Vring
+ */
+static inline int wil_vring_avail_tx(struct vring *vring)
+{
+	u32 swhead = vring->swhead;
+	u32 swtail = vring->swtail;
+	int used = (vring->size + swhead - swtail) % vring->size;
+
+	return vring->size - used - 1;
+}
+
+static int wil_vring_alloc(struct wil6210_priv *wil, struct vring *vring)
+{
+	struct device *dev = wil_to_dev(wil);
+	size_t sz = vring->size * sizeof(vring->va[0]);
+	uint i;
+
+	BUILD_BUG_ON(sizeof(vring->va[0]) != 32);
+
+	vring->swhead = 0;
+	vring->swtail = 0;
+	vring->ctx = kzalloc(vring->size * sizeof(vring->ctx[0]), GFP_KERNEL);
+	if (!vring->ctx) {
+		wil_err(wil, "vring_alloc [%d] failed to alloc ctx mem\n",
+			vring->size);
+		vring->va = NULL;
+		return -ENOMEM;
+	}
+	/*
+	 * vring->va should be aligned on its size rounded up to power of 2
+	 * This is granted by the dma_alloc_coherent
+	 */
+	vring->va = dma_alloc_coherent(dev, sz, &vring->pa, GFP_KERNEL);
+	if (!vring->va) {
+		wil_err(wil, "vring_alloc [%d] failed to alloc DMA mem\n",
+			vring->size);
+		kfree(vring->ctx);
+		vring->ctx = NULL;
+		return -ENOMEM;
+	}
+	/* initially, all descriptors are SW owned
+	 * For Tx and Rx, ownership bit is at the same location, thus
+	 * we can use any
+	 */
+	for (i = 0; i < vring->size; i++) {
+		volatile struct vring_tx_desc *d = &(vring->va[i].tx);
+		d->dma.status = TX_DMA_STATUS_DU;
+	}
+
+	wil_dbg(wil, "vring[%d] 0x%p:0x%016llx 0x%p\n", vring->size,
+		vring->va, (unsigned long long)vring->pa, vring->ctx);
+
+	return 0;
+}
+
+static void wil_vring_free(struct wil6210_priv *wil, struct vring *vring,
+			   int tx)
+{
+	struct device *dev = wil_to_dev(wil);
+	size_t sz = vring->size * sizeof(vring->va[0]);
+
+	while (!wil_vring_is_empty(vring)) {
+		if (tx) {
+			volatile struct vring_tx_desc *d =
+					&vring->va[vring->swtail].tx;
+			dma_addr_t pa = d->dma.addr_low |
+					((u64)d->dma.addr_high << 32);
+			struct sk_buff *skb = vring->ctx[vring->swtail];
+			if (skb) {
+				dma_unmap_single(dev, pa, d->dma.length,
+						 DMA_TO_DEVICE);
+				dev_kfree_skb_any(skb);
+				vring->ctx[vring->swtail] = NULL;
+			} else {
+				dma_unmap_page(dev, pa, d->dma.length,
+					       DMA_TO_DEVICE);
+			}
+			vring->swtail = wil_vring_next_tail(vring);
+		} else { /* rx */
+			volatile struct vring_rx_desc *d =
+					&vring->va[vring->swtail].rx;
+			dma_addr_t pa = d->dma.addr_low |
+					((u64)d->dma.addr_high << 32);
+			struct sk_buff *skb = vring->ctx[vring->swhead];
+			dma_unmap_single(dev, pa, d->dma.length,
+					 DMA_FROM_DEVICE);
+			kfree_skb(skb);
+			wil_vring_advance_head(vring, 1);
+		}
+	}
+	dma_free_coherent(dev, sz, (void *)vring->va, vring->pa);
+	kfree(vring->ctx);
+	vring->pa = 0;
+	vring->va = NULL;
+	vring->ctx = NULL;
+}
+
+/**
+ * Allocate one skb for Rx VRING
+ *
+ * Safe to call from IRQ
+ */
+static int wil_vring_alloc_skb(struct wil6210_priv *wil, struct vring *vring,
+			       u32 i, int headroom)
+{
+	struct device *dev = wil_to_dev(wil);
+	unsigned int sz = RX_BUF_LEN;
+	volatile struct vring_rx_desc *d = &(vring->va[i].rx);
+	dma_addr_t pa;
+
+	/* TODO align */
+	struct sk_buff *skb = dev_alloc_skb(sz + headroom);
+	if (unlikely(!skb))
+		return -ENOMEM;
+
+	skb_reserve(skb, headroom);
+	skb_put(skb, sz);
+
+	pa = dma_map_single(dev, skb->data, skb->len, DMA_FROM_DEVICE);
+	if (unlikely(dma_mapping_error(dev, pa))) {
+		kfree_skb(skb);
+		return -ENOMEM;
+	}
+
+	d->dma.d0 = BIT(9) | RX_DMA_D0_CMD_DMA_IT;
+	d->dma.addr_low = lower_32_bits(pa);
+	d->dma.addr_high = (u16)upper_32_bits(pa);
+	/* ip_length don't care */
+	/* b11 don't care */
+	/* error don't care */
+	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
+	d->dma.length = sz;
+	vring->ctx[i] = skb;
+
+	return 0;
+}
+
+/**
+ * Adds radiotap header
+ *
+ * Any error indicated as "Bad FCS"
+ *
+ * Vendor data for 04:ce:14-1 (Wilocity-1) consists of:
+ *  - Rx descriptor: 32 bytes
+ *  - Phy info
+ */
+static void wil_rx_add_radiotap_header(struct wil6210_priv *wil,
+				       struct sk_buff *skb,
+				       volatile struct vring_rx_desc *d)
+{
+	struct wireless_dev *wdev = wil->wdev;
+	struct wil6210_rtap {
+		struct ieee80211_radiotap_header rthdr;
+		/* fields should be in the order of bits in rthdr.it_present */
+		/* flags */
+		u8 flags;
+		/* channel */
+		__le16 chnl_freq __aligned(2);
+		__le16 chnl_flags;
+		/* MCS */
+		u8 mcs_present;
+		u8 mcs_flags;
+		u8 mcs_index;
+	} __packed;
+	struct wil6210_rtap_vendor {
+		struct wil6210_rtap rtap;
+		/* vendor */
+		u8 vendor_oui[3] __aligned(2);
+		u8 vendor_ns;
+		__le16 vendor_skip;
+		u8 vendor_data[0];
+	} __packed;
+	struct wil6210_rtap_vendor *rtap_vendor;
+	int rtap_len = sizeof(struct wil6210_rtap);
+	int phy_length = 0; /* phy info header size, bytes */
+	static char phy_data[128];
+	struct ieee80211_channel *ch = wdev->preset_chandef.chan;
+
+	if (rtap_include_phy_info) {
+		rtap_len = sizeof(*rtap_vendor) + sizeof(*d);
+		/* calculate additional length */
+		if (d->dma.status & RX_DMA_STATUS_PHY_INFO) {
+			/**
+			 * PHY info starts from 8-byte boundary
+			 * there are 8-byte lines, last line may be partially
+			 * written (HW bug), thus FW configures for last line
+			 * to be excessive. Driver skips this last line.
+			 */
+			int len = min_t(int, 8 + sizeof(phy_data),
+					wil_rxdesc_phy_length(d));
+			if (len > 8) {
+				void *p = skb_tail_pointer(skb);
+				void *pa = PTR_ALIGN(p, 8);
+				if (skb_tailroom(skb) >= len + (pa - p)) {
+					phy_length = len - 8;
+					memcpy(phy_data, pa, phy_length);
+				}
+			}
+		}
+		rtap_len += phy_length;
+	}
+
+	if (skb_headroom(skb) < rtap_len &&
+	    pskb_expand_head(skb, rtap_len, 0, GFP_ATOMIC)) {
+		wil_err(wil, "Unable to expand headrom to %d\n", rtap_len);
+		return;
+	}
+
+	rtap_vendor = (void *)skb_push(skb, rtap_len);
+	memset(rtap_vendor, 0, rtap_len);
+
+	rtap_vendor->rtap.rthdr.it_version = PKTHDR_RADIOTAP_VERSION;
+	rtap_vendor->rtap.rthdr.it_len = cpu_to_le16(rtap_len);
+	rtap_vendor->rtap.rthdr.it_present = cpu_to_le32(
+			(1 << IEEE80211_RADIOTAP_FLAGS) |
+			(1 << IEEE80211_RADIOTAP_CHANNEL) |
+			(1 << IEEE80211_RADIOTAP_MCS));
+	if (d->dma.status & RX_DMA_STATUS_ERROR)
+		rtap_vendor->rtap.flags |= IEEE80211_RADIOTAP_F_BADFCS;
+
+	rtap_vendor->rtap.chnl_freq = cpu_to_le16(ch ? ch->center_freq : 58320);
+	rtap_vendor->rtap.chnl_flags = cpu_to_le16(0);
+
+	rtap_vendor->rtap.mcs_present = IEEE80211_RADIOTAP_MCS_HAVE_MCS;
+	rtap_vendor->rtap.mcs_flags = 0;
+	rtap_vendor->rtap.mcs_index = wil_rxdesc_mcs(d);
+
+	if (rtap_include_phy_info) {
+		rtap_vendor->rtap.rthdr.it_present |= cpu_to_le32(1 <<
+				IEEE80211_RADIOTAP_VENDOR_NAMESPACE);
+		/* OUI for Wilocity 04:ce:14 */
+		rtap_vendor->vendor_oui[0] = 0x04;
+		rtap_vendor->vendor_oui[1] = 0xce;
+		rtap_vendor->vendor_oui[2] = 0x14;
+		rtap_vendor->vendor_ns = 1;
+		/* Rx descriptor + PHY data  */
+		rtap_vendor->vendor_skip = cpu_to_le16(sizeof(*d) +
+						       phy_length);
+		memcpy(rtap_vendor->vendor_data, (void *)d, sizeof(*d));
+		memcpy(rtap_vendor->vendor_data + sizeof(*d), phy_data,
+		       phy_length);
+	}
+}
+
+/*
+ * Fast swap in place between 2 registers
+ */
+static void wil_swap_u16(u16 *a, u16 *b)
+{
+	*a ^= *b;
+	*b ^= *a;
+	*a ^= *b;
+}
+
+static void wil_swap_ethaddr(void *data)
+{
+	struct ethhdr *eth = data;
+	u16 *s = (u16 *)eth->h_source;
+	u16 *d = (u16 *)eth->h_dest;
+
+	wil_swap_u16(s++, d++);
+	wil_swap_u16(s++, d++);
+	wil_swap_u16(s, d);
+}
+
+/**
+ * reap 1 frame from @swhead
+ *
+ * Safe to call from IRQ
+ */
+static struct sk_buff *wil_vring_reap_rx(struct wil6210_priv *wil,
+					 struct vring *vring)
+{
+	struct device *dev = wil_to_dev(wil);
+	struct net_device *ndev = wil_to_ndev(wil);
+	volatile struct vring_rx_desc *d;
+	struct sk_buff *skb;
+	dma_addr_t pa;
+	unsigned int sz = RX_BUF_LEN;
+	u8 ftype;
+	u8 ds_bits;
+
+	if (wil_vring_is_empty(vring))
+		return NULL;
+
+	d = &(vring->va[vring->swhead].rx);
+	if (!(d->dma.status & RX_DMA_STATUS_DU)) {
+		/* it is not error, we just reached end of Rx done area */
+		return NULL;
+	}
+
+	pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
+	skb = vring->ctx[vring->swhead];
+	dma_unmap_single(dev, pa, sz, DMA_FROM_DEVICE);
+	skb_trim(skb, d->dma.length);
+
+	wil->stats.last_mcs_rx = wil_rxdesc_mcs(d);
+
+	/* use radiotap header only if required */
+	if (ndev->type == ARPHRD_IEEE80211_RADIOTAP)
+		wil_rx_add_radiotap_header(wil, skb, d);
+
+	wil_dbg_TXRX(wil, "Rx[%3d] : %d bytes\n", vring->swhead, d->dma.length);
+	wil_hex_dump_TXRX("Rx ", DUMP_PREFIX_NONE, 32, 4,
+			  (const void *)d, sizeof(*d), false);
+
+	wil_vring_advance_head(vring, 1);
+
+	/* no extra checks if in sniffer mode */
+	if (ndev->type != ARPHRD_ETHER)
+		return skb;
+	/*
+	 * Non-data frames may be delivered through Rx DMA channel (ex: BAR)
+	 * Driver should recognize it by frame type, that is found
+	 * in Rx descriptor. If type is not data, it is 802.11 frame as is
+	 */
+	ftype = wil_rxdesc_ftype(d) << 2;
+	if (ftype != IEEE80211_FTYPE_DATA) {
+		wil_dbg_TXRX(wil, "Non-data frame ftype 0x%08x\n", ftype);
+		/* TODO: process it */
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	if (skb->len < ETH_HLEN) {
+		wil_err(wil, "Short frame, len = %d\n", skb->len);
+		/* TODO: process it (i.e. BAR) */
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	ds_bits = wil_rxdesc_ds_bits(d);
+	if (ds_bits == 1) {
+		/*
+		 * HW bug - in ToDS mode, i.e. Rx on AP side,
+		 * addresses get swapped
+		 */
+		wil_swap_ethaddr(skb->data);
+	}
+
+	return skb;
+}
+
+/**
+ * allocate and fill up to @count buffers in rx ring
+ * buffers posted at @swtail
+ */
+static int wil_rx_refill(struct wil6210_priv *wil, int count)
+{
+	struct net_device *ndev = wil_to_ndev(wil);
+	struct vring *v = &wil->vring_rx;
+	u32 next_tail;
+	int rc = 0;
+	int headroom = ndev->type == ARPHRD_IEEE80211_RADIOTAP ?
+			WIL6210_RTAP_SIZE : 0;
+
+	for (; next_tail = wil_vring_next_tail(v),
+			(next_tail != v->swhead) && (count-- > 0);
+			v->swtail = next_tail) {
+		rc = wil_vring_alloc_skb(wil, v, v->swtail, headroom);
+		if (rc) {
+			wil_err(wil, "Error %d in wil_rx_refill[%d]\n",
+				rc, v->swtail);
+			break;
+		}
+	}
+	iowrite32(v->swtail, wil->csr + HOSTADDR(v->hwtail));
+
+	return rc;
+}
+
+/*
+ * Pass Rx packet to the netif. Update statistics.
+ */
+static void wil_netif_rx_any(struct sk_buff *skb, struct net_device *ndev)
+{
+	int rc;
+	unsigned int len = skb->len;
+
+	if (in_interrupt())
+		rc = netif_rx(skb);
+	else
+		rc = netif_rx_ni(skb);
+
+	if (likely(rc == NET_RX_SUCCESS)) {
+		ndev->stats.rx_packets++;
+		ndev->stats.rx_bytes += len;
+
+	} else {
+		ndev->stats.rx_dropped++;
+	}
+}
+
+/**
+ * Proceed all completed skb's from Rx VRING
+ *
+ * Safe to call from IRQ
+ */
+void wil_rx_handle(struct wil6210_priv *wil)
+{
+	struct net_device *ndev = wil_to_ndev(wil);
+	struct vring *v = &wil->vring_rx;
+	struct sk_buff *skb;
+
+	if (!v->va) {
+		wil_err(wil, "Rx IRQ while Rx not yet initialized\n");
+		return;
+	}
+	wil_dbg_TXRX(wil, "%s()\n", __func__);
+	while (NULL != (skb = wil_vring_reap_rx(wil, v))) {
+		wil_hex_dump_TXRX("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
+				  skb->data, skb_headlen(skb), false);
+
+		skb_orphan(skb);
+
+		if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
+			skb->dev = ndev;
+			skb_reset_mac_header(skb);
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			skb->pkt_type = PACKET_OTHERHOST;
+			skb->protocol = htons(ETH_P_802_2);
+
+		} else {
+			skb->protocol = eth_type_trans(skb, ndev);
+		}
+
+		wil_netif_rx_any(skb, ndev);
+	}
+	wil_rx_refill(wil, v->size);
+}
+
+int wil_rx_init(struct wil6210_priv *wil)
+{
+	struct net_device *ndev = wil_to_ndev(wil);
+	struct wireless_dev *wdev = wil->wdev;
+	struct vring *vring = &wil->vring_rx;
+	int rc;
+	struct wmi_cfg_rx_chain_cmd cmd = {
+		.action = WMI_RX_CHAIN_ADD,
+		.rx_sw_ring = {
+			.max_mpdu_size = cpu_to_le16(RX_BUF_LEN),
+		},
+		.mid = 0, /* TODO - what is it? */
+		.decap_trans_type = WMI_DECAP_TYPE_802_3,
+	};
+	struct {
+		struct wil6210_mbox_hdr_wmi wmi;
+		struct wmi_cfg_rx_chain_done_event evt;
+	} __packed evt;
+
+	vring->size = WIL6210_RX_RING_SIZE;
+	rc = wil_vring_alloc(wil, vring);
+	if (rc)
+		return rc;
+
+	cmd.rx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
+	cmd.rx_sw_ring.ring_size = cpu_to_le16(vring->size);
+	if (wdev->iftype == NL80211_IFTYPE_MONITOR) {
+		struct ieee80211_channel *ch = wdev->preset_chandef.chan;
+
+		cmd.sniffer_cfg.mode = cpu_to_le32(WMI_SNIFFER_ON);
+		if (ch)
+			cmd.sniffer_cfg.channel = ch->hw_value - 1;
+		cmd.sniffer_cfg.phy_info_mode =
+			cpu_to_le32(ndev->type == ARPHRD_IEEE80211_RADIOTAP);
+		cmd.sniffer_cfg.phy_support =
+			cpu_to_le32((wil->monitor_flags & MONITOR_FLAG_CONTROL)
+				    ? WMI_SNIFFER_CP : WMI_SNIFFER_DP);
+	}
+	/* typical time for secure PCP is 840ms */
+	rc = wmi_call(wil, WMI_CFG_RX_CHAIN_CMDID, &cmd, sizeof(cmd),
+		      WMI_CFG_RX_CHAIN_DONE_EVENTID, &evt, sizeof(evt), 2000);
+	if (rc)
+		goto err_free;
+
+	vring->hwtail = le32_to_cpu(evt.evt.rx_ring_tail_ptr);
+
+	wil_dbg(wil, "Rx init: status %d tail 0x%08x\n",
+		le32_to_cpu(evt.evt.status), vring->hwtail);
+
+	rc = wil_rx_refill(wil, vring->size);
+	if (rc)
+		goto err_free;
+
+	return 0;
+ err_free:
+	wil_vring_free(wil, vring, 0);
+
+	return rc;
+}
+
+void wil_rx_fini(struct wil6210_priv *wil)
+{
+	struct vring *vring = &wil->vring_rx;
+
+	if (vring->va) {
+		int rc;
+		struct wmi_cfg_rx_chain_cmd cmd = {
+			.action = cpu_to_le32(WMI_RX_CHAIN_DEL),
+			.rx_sw_ring = {
+				.max_mpdu_size = cpu_to_le16(RX_BUF_LEN),
+			},
+		};
+		struct {
+			struct wil6210_mbox_hdr_wmi wmi;
+			struct wmi_cfg_rx_chain_done_event cfg;
+		} __packed wmi_rx_cfg_reply;
+
+		rc = wmi_call(wil, WMI_CFG_RX_CHAIN_CMDID, &cmd, sizeof(cmd),
+			      WMI_CFG_RX_CHAIN_DONE_EVENTID,
+			      &wmi_rx_cfg_reply, sizeof(wmi_rx_cfg_reply),
+			      100);
+		wil_vring_free(wil, vring, 0);
+	}
+}
+
+int wil_vring_init_tx(struct wil6210_priv *wil, int id, int size,
+		      int cid, int tid)
+{
+	int rc;
+	struct wmi_vring_cfg_cmd cmd = {
+		.action = cpu_to_le32(WMI_VRING_CMD_ADD),
+		.vring_cfg = {
+			.tx_sw_ring = {
+				.max_mpdu_size = cpu_to_le16(TX_BUF_LEN),
+			},
+			.ringid = id,
+			.cidxtid = (cid & 0xf) | ((tid & 0xf) << 4),
+			.encap_trans_type = WMI_VRING_ENC_TYPE_802_3,
+			.mac_ctrl = 0,
+			.to_resolution = 0,
+			.agg_max_wsize = 16,
+			.schd_params = {
+				.priority = cpu_to_le16(0),
+				.timeslot_us = cpu_to_le16(0xfff),
+			},
+		},
+	};
+	struct {
+		struct wil6210_mbox_hdr_wmi wmi;
+		struct wmi_vring_cfg_done_event cmd;
+	} __packed reply;
+	struct vring *vring = &wil->vring_tx[id];
+
+	if (vring->va) {
+		wil_err(wil, "Tx ring [%d] already allocated\n", id);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	vring->size = size;
+	rc = wil_vring_alloc(wil, vring);
+	if (rc)
+		goto out;
+
+	cmd.vring_cfg.tx_sw_ring.ring_mem_base = cpu_to_le64(vring->pa);
+	cmd.vring_cfg.tx_sw_ring.ring_size = cpu_to_le16(vring->size);
+
+	rc = wmi_call(wil, WMI_VRING_CFG_CMDID, &cmd, sizeof(cmd),
+		      WMI_VRING_CFG_DONE_EVENTID, &reply, sizeof(reply), 100);
+	if (rc)
+		goto out_free;
+
+	if (reply.cmd.status != WMI_VRING_CFG_SUCCESS) {
+		wil_err(wil, "Tx config failed, status 0x%02x\n",
+			reply.cmd.status);
+		goto out_free;
+	}
+	vring->hwtail = le32_to_cpu(reply.cmd.tx_vring_tail_ptr);
+
+	return 0;
+ out_free:
+	wil_vring_free(wil, vring, 1);
+ out:
+
+	return rc;
+}
+
+void wil_vring_fini_tx(struct wil6210_priv *wil, int id)
+{
+	struct vring *vring = &wil->vring_tx[id];
+
+	if (!vring->va)
+		return;
+
+	wil_vring_free(wil, vring, 1);
+}
+
+static struct vring *wil_find_tx_vring(struct wil6210_priv *wil,
+				       struct sk_buff *skb)
+{
+	struct vring *v = &wil->vring_tx[0];
+
+	if (v->va)
+		return v;
+
+	return NULL;
+}
+
+static int wil_tx_desc_map(volatile struct vring_tx_desc *d,
+			   dma_addr_t pa, u32 len)
+{
+	d->dma.addr_low = lower_32_bits(pa);
+	d->dma.addr_high = (u16)upper_32_bits(pa);
+	d->dma.ip_length = 0;
+	/* 0..6: mac_length; 7:ip_version 0-IP6 1-IP4*/
+	d->dma.b11 = 0/*14 | BIT(7)*/;
+	d->dma.error = 0;
+	d->dma.status = 0; /* BIT(0) should be 0 for HW_OWNED */
+	d->dma.length = len;
+	d->dma.d0 = 0;
+	d->mac.d[0] = 0;
+	d->mac.d[1] = 0;
+	d->mac.d[2] = 0;
+	d->mac.ucode_cmd = 0;
+	/* use dst index 0 */
+	d->mac.d[1] |= BIT(MAC_CFG_DESC_TX_1_DST_INDEX_EN_POS) |
+		       (0 << MAC_CFG_DESC_TX_1_DST_INDEX_POS);
+	/* translation type:  0 - bypass; 1 - 802.3; 2 - native wifi */
+	d->mac.d[2] = BIT(MAC_CFG_DESC_TX_2_SNAP_HDR_INSERTION_EN_POS) |
+		      (1 << MAC_CFG_DESC_TX_2_L2_TRANSLATION_TYPE_POS);
+
+	return 0;
+}
+
+static int wil_tx_vring(struct wil6210_priv *wil, struct vring *vring,
+			struct sk_buff *skb)
+{
+	struct device *dev = wil_to_dev(wil);
+	volatile struct vring_tx_desc *d;
+	u32 swhead = vring->swhead;
+	int avail = wil_vring_avail_tx(vring);
+	int nr_frags = skb_shinfo(skb)->nr_frags;
+	uint f;
+	int vring_index = vring - wil->vring_tx;
+	uint i = swhead;
+	dma_addr_t pa;
+
+	wil_dbg_TXRX(wil, "%s()\n", __func__);
+
+	if (avail < vring->size/8)
+		netif_tx_stop_all_queues(wil_to_ndev(wil));
+	if (avail < 1 + nr_frags) {
+		wil_err(wil, "Tx ring full. No space for %d fragments\n",
+			1 + nr_frags);
+		return -ENOMEM;
+	}
+	d = &(vring->va[i].tx);
+
+	/* FIXME FW can accept only unicast frames for the peer */
+	memcpy(skb->data, wil->dst_addr[vring_index], ETH_ALEN);
+
+	pa = dma_map_single(dev, skb->data,
+			skb_headlen(skb), DMA_TO_DEVICE);
+
+	wil_dbg_TXRX(wil, "Tx skb %d bytes %p -> %#08llx\n", skb_headlen(skb),
+		     skb->data, (unsigned long long)pa);
+	wil_hex_dump_TXRX("Tx ", DUMP_PREFIX_OFFSET, 16, 1,
+			  skb->data, skb_headlen(skb), false);
+
+	if (unlikely(dma_mapping_error(dev, pa)))
+		return -EINVAL;
+	/* 1-st segment */
+	wil_tx_desc_map(d, pa, skb_headlen(skb));
+	d->mac.d[2] |= ((nr_frags + 1) <<
+		       MAC_CFG_DESC_TX_2_NUM_OF_DESCRIPTORS_POS);
+	/* middle segments */
+	for (f = 0; f < nr_frags; f++) {
+		const struct skb_frag_struct *frag =
+				&skb_shinfo(skb)->frags[f];
+		int len = skb_frag_size(frag);
+		i = (swhead + f + 1) % vring->size;
+		d = &(vring->va[i].tx);
+		pa = skb_frag_dma_map(dev, frag, 0, skb_frag_size(frag),
+				DMA_TO_DEVICE);
+		if (unlikely(dma_mapping_error(dev, pa)))
+			goto dma_error;
+		wil_tx_desc_map(d, pa, len);
+		vring->ctx[i] = NULL;
+	}
+	/* for the last seg only */
+	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_EOP_POS);
+	d->dma.d0 |= BIT(9); /* BUG: undocumented bit */
+	d->dma.d0 |= BIT(DMA_CFG_DESC_TX_0_CMD_DMA_IT_POS);
+	d->dma.d0 |= (vring_index << DMA_CFG_DESC_TX_0_QID_POS);
+
+	wil_hex_dump_TXRX("Tx ", DUMP_PREFIX_NONE, 32, 4,
+			  (const void *)d, sizeof(*d), false);
+
+	/* advance swhead */
+	wil_vring_advance_head(vring, nr_frags + 1);
+	wil_dbg_TXRX(wil, "Tx swhead %d -> %d\n", swhead, vring->swhead);
+	iowrite32(vring->swhead, wil->csr + HOSTADDR(vring->hwtail));
+	/* hold reference to skb
+	 * to prevent skb release before accounting
+	 * in case of immediate "tx done"
+	 */
+	vring->ctx[i] = skb_get(skb);
+
+	return 0;
+ dma_error:
+	/* unmap what we have mapped */
+	/* Note: increment @f to operate with positive index */
+	for (f++; f > 0; f--) {
+		i = (swhead + f) % vring->size;
+		d = &(vring->va[i].tx);
+		d->dma.status = TX_DMA_STATUS_DU;
+		pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
+		if (vring->ctx[i])
+			dma_unmap_single(dev, pa, d->dma.length, DMA_TO_DEVICE);
+		else
+			dma_unmap_page(dev, pa, d->dma.length, DMA_TO_DEVICE);
+	}
+
+	return -EINVAL;
+}
+
+
+netdev_tx_t wil_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct wil6210_priv *wil = ndev_to_wil(ndev);
+	struct vring *vring;
+	int rc;
+
+	wil_dbg_TXRX(wil, "%s()\n", __func__);
+	if (!test_bit(wil_status_fwready, &wil->status)) {
+		wil_err(wil, "FW not ready\n");
+		goto drop;
+	}
+	if (!test_bit(wil_status_fwconnected, &wil->status)) {
+		wil_err(wil, "FW not connected\n");
+		goto drop;
+	}
+	if (wil->wdev->iftype == NL80211_IFTYPE_MONITOR) {
+		wil_err(wil, "Xmit in monitor mode not supported\n");
+		goto drop;
+	}
+	if (skb->protocol == cpu_to_be16(ETH_P_PAE)) {
+		rc = wmi_tx_eapol(wil, skb);
+	} else {
+		/* find vring */
+		vring = wil_find_tx_vring(wil, skb);
+		if (!vring) {
+			wil_err(wil, "No Tx VRING available\n");
+			goto drop;
+		}
+		/* set up vring entry */
+		rc = wil_tx_vring(wil, vring, skb);
+	}
+	switch (rc) {
+	case 0:
+		ndev->stats.tx_packets++;
+		ndev->stats.tx_bytes += skb->len;
+		dev_kfree_skb_any(skb);
+		return NETDEV_TX_OK;
+	case -ENOMEM:
+		return NETDEV_TX_BUSY;
+	default:
+		; /* goto drop; */
+		break;
+	}
+ drop:
+	netif_tx_stop_all_queues(ndev);
+	ndev->stats.tx_dropped++;
+	dev_kfree_skb_any(skb);
+
+	return NET_XMIT_DROP;
+}
+
+/**
+ * Clean up transmitted skb's from the Tx VRING
+ *
+ * Safe to call from IRQ
+ */
+void wil_tx_complete(struct wil6210_priv *wil, int ringid)
+{
+	struct device *dev = wil_to_dev(wil);
+	struct vring *vring = &wil->vring_tx[ringid];
+
+	if (!vring->va) {
+		wil_err(wil, "Tx irq[%d]: vring not initialized\n", ringid);
+		return;
+	}
+
+	wil_dbg_TXRX(wil, "%s(%d)\n", __func__, ringid);
+
+	while (!wil_vring_is_empty(vring)) {
+		volatile struct vring_tx_desc *d = &vring->va[vring->swtail].tx;
+		dma_addr_t pa;
+		struct sk_buff *skb;
+		if (!(d->dma.status & TX_DMA_STATUS_DU))
+			break;
+
+		wil_dbg_TXRX(wil,
+			     "Tx[%3d] : %d bytes, status 0x%02x err 0x%02x\n",
+			     vring->swtail, d->dma.length, d->dma.status,
+			     d->dma.error);
+		wil_hex_dump_TXRX("TxC ", DUMP_PREFIX_NONE, 32, 4,
+				  (const void *)d, sizeof(*d), false);
+
+		pa = d->dma.addr_low | ((u64)d->dma.addr_high << 32);
+		skb = vring->ctx[vring->swtail];
+		if (skb) {
+			dma_unmap_single(dev, pa, d->dma.length, DMA_TO_DEVICE);
+			dev_kfree_skb_any(skb);
+			vring->ctx[vring->swtail] = NULL;
+		} else {
+			dma_unmap_page(dev, pa, d->dma.length, DMA_TO_DEVICE);
+		}
+		d->dma.addr_low = 0;
+		d->dma.addr_high = 0;
+		d->dma.length = 0;
+		d->dma.status = TX_DMA_STATUS_DU;
+		vring->swtail = wil_vring_next_tail(vring);
+	}
+	if (wil_vring_avail_tx(vring) > vring->size/4)
+		netif_tx_wake_all_queues(wil_to_ndev(wil));
+}