Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1351 insertions, 0 deletions

diff --git a/drivers/platform/mellanox/mlxbf-tmfifo.c b/drivers/platform/mellanox/mlxbf-tmfifo.c
new file mode 100644
index 000000000..9925a6d94
--- /dev/null
+++ b/drivers/platform/mellanox/mlxbf-tmfifo.c
@@ -0,0 +1,1351 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Mellanox BlueField SoC TmFifo driver
+ *
+ * Copyright (C) 2019 Mellanox Technologies
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/circ_buf.h>
+#include <linux/efi.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#include <linux/virtio_config.h>
+#include <linux/virtio_console.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_net.h>
+#include <linux/virtio_ring.h>
+
+#include "mlxbf-tmfifo-regs.h"
+
+/* Vring size. */
+#define MLXBF_TMFIFO_VRING_SIZE			SZ_1K
+
+/* Console Tx buffer size. */
+#define MLXBF_TMFIFO_CON_TX_BUF_SIZE		SZ_32K
+
+/* Console Tx buffer reserved space. */
+#define MLXBF_TMFIFO_CON_TX_BUF_RSV_SIZE	8
+
+/* House-keeping timer interval. */
+#define MLXBF_TMFIFO_TIMER_INTERVAL		(HZ / 10)
+
+/* Virtual devices sharing the TM FIFO. */
+#define MLXBF_TMFIFO_VDEV_MAX		(VIRTIO_ID_CONSOLE + 1)
+
+/*
+ * Reserve 1/16 of TmFifo space, so console messages are not starved by
+ * the networking traffic.
+ */
+#define MLXBF_TMFIFO_RESERVE_RATIO		16
+
+/* Message with data needs at least two words (for header & data). */
+#define MLXBF_TMFIFO_DATA_MIN_WORDS		2
+
+struct mlxbf_tmfifo;
+
+/**
+ * mlxbf_tmfifo_vring - Structure of the TmFifo virtual ring
+ * @va: virtual address of the ring
+ * @dma: dma address of the ring
+ * @vq: pointer to the virtio virtqueue
+ * @desc: current descriptor of the pending packet
+ * @desc_head: head descriptor of the pending packet
+ * @drop_desc: dummy desc for packet dropping
+ * @cur_len: processed length of the current descriptor
+ * @rem_len: remaining length of the pending packet
+ * @pkt_len: total length of the pending packet
+ * @next_avail: next avail descriptor id
+ * @num: vring size (number of descriptors)
+ * @align: vring alignment size
+ * @index: vring index
+ * @vdev_id: vring virtio id (VIRTIO_ID_xxx)
+ * @fifo: pointer to the tmfifo structure
+ */
+struct mlxbf_tmfifo_vring {
+	void *va;
+	dma_addr_t dma;
+	struct virtqueue *vq;
+	struct vring_desc *desc;
+	struct vring_desc *desc_head;
+	struct vring_desc drop_desc;
+	int cur_len;
+	int rem_len;
+	u32 pkt_len;
+	u16 next_avail;
+	int num;
+	int align;
+	int index;
+	int vdev_id;
+	struct mlxbf_tmfifo *fifo;
+};
+
+/* Check whether vring is in drop mode. */
+#define IS_VRING_DROP(_r) ({ \
+	typeof(_r) (r) = (_r); \
+	(r->desc_head == &r->drop_desc ? true : false); })
+
+/* A stub length to drop maximum length packet. */
+#define VRING_DROP_DESC_MAX_LEN		GENMASK(15, 0)
+
+/* Interrupt types. */
+enum {
+	MLXBF_TM_RX_LWM_IRQ,
+	MLXBF_TM_RX_HWM_IRQ,
+	MLXBF_TM_TX_LWM_IRQ,
+	MLXBF_TM_TX_HWM_IRQ,
+	MLXBF_TM_MAX_IRQ
+};
+
+/* Ring types (Rx & Tx). */
+enum {
+	MLXBF_TMFIFO_VRING_RX,
+	MLXBF_TMFIFO_VRING_TX,
+	MLXBF_TMFIFO_VRING_MAX
+};
+
+/**
+ * mlxbf_tmfifo_vdev - Structure of the TmFifo virtual device
+ * @vdev: virtio device, in which the vdev.id.device field has the
+ *        VIRTIO_ID_xxx id to distinguish the virtual device.
+ * @status: status of the device
+ * @features: supported features of the device
+ * @vrings: array of tmfifo vrings of this device
+ * @config.cons: virtual console config -
+ *               select if vdev.id.device is VIRTIO_ID_CONSOLE
+ * @config.net: virtual network config -
+ *              select if vdev.id.device is VIRTIO_ID_NET
+ * @tx_buf: tx buffer used to buffer data before writing into the FIFO
+ */
+struct mlxbf_tmfifo_vdev {
+	struct virtio_device vdev;
+	u8 status;
+	u64 features;
+	struct mlxbf_tmfifo_vring vrings[MLXBF_TMFIFO_VRING_MAX];
+	union {
+		struct virtio_console_config cons;
+		struct virtio_net_config net;
+	} config;
+	struct circ_buf tx_buf;
+};
+
+/**
+ * mlxbf_tmfifo_irq_info - Structure of the interrupt information
+ * @fifo: pointer to the tmfifo structure
+ * @irq: interrupt number
+ * @index: index into the interrupt array
+ */
+struct mlxbf_tmfifo_irq_info {
+	struct mlxbf_tmfifo *fifo;
+	int irq;
+	int index;
+};
+
+/**
+ * mlxbf_tmfifo - Structure of the TmFifo
+ * @vdev: array of the virtual devices running over the TmFifo
+ * @lock: lock to protect the TmFifo access
+ * @rx_base: mapped register base address for the Rx FIFO
+ * @tx_base: mapped register base address for the Tx FIFO
+ * @rx_fifo_size: number of entries of the Rx FIFO
+ * @tx_fifo_size: number of entries of the Tx FIFO
+ * @pend_events: pending bits for deferred events
+ * @irq_info: interrupt information
+ * @work: work struct for deferred process
+ * @timer: background timer
+ * @vring: Tx/Rx ring
+ * @spin_lock: Tx/Rx spin lock
+ * @is_ready: ready flag
+ */
+struct mlxbf_tmfifo {
+	struct mlxbf_tmfifo_vdev *vdev[MLXBF_TMFIFO_VDEV_MAX];
+	struct mutex lock;		/* TmFifo lock */
+	void __iomem *rx_base;
+	void __iomem *tx_base;
+	int rx_fifo_size;
+	int tx_fifo_size;
+	unsigned long pend_events;
+	struct mlxbf_tmfifo_irq_info irq_info[MLXBF_TM_MAX_IRQ];
+	struct work_struct work;
+	struct timer_list timer;
+	struct mlxbf_tmfifo_vring *vring[2];
+	spinlock_t spin_lock[2];	/* spin lock */
+	bool is_ready;
+};
+
+/**
+ * mlxbf_tmfifo_msg_hdr - Structure of the TmFifo message header
+ * @type: message type
+ * @len: payload length in network byte order. Messages sent into the FIFO
+ *       will be read by the other side as data stream in the same byte order.
+ *       The length needs to be encoded into network order so both sides
+ *       could understand it.
+ */
+struct mlxbf_tmfifo_msg_hdr {
+	u8 type;
+	__be16 len;
+	u8 unused[5];
+} __packed __aligned(sizeof(u64));
+
+/*
+ * Default MAC.
+ * This MAC address will be read from EFI persistent variable if configured.
+ * It can also be reconfigured with standard Linux tools.
+ */
+static u8 mlxbf_tmfifo_net_default_mac[ETH_ALEN] = {
+	0x00, 0x1A, 0xCA, 0xFF, 0xFF, 0x01
+};
+
+/* EFI variable name of the MAC address. */
+static efi_char16_t mlxbf_tmfifo_efi_name[] = L"RshimMacAddr";
+
+/* Maximum L2 header length. */
+#define MLXBF_TMFIFO_NET_L2_OVERHEAD	(ETH_HLEN + VLAN_HLEN)
+
+/* Supported virtio-net features. */
+#define MLXBF_TMFIFO_NET_FEATURES \
+	(BIT_ULL(VIRTIO_NET_F_MTU) | BIT_ULL(VIRTIO_NET_F_STATUS) | \
+	 BIT_ULL(VIRTIO_NET_F_MAC))
+
+#define mlxbf_vdev_to_tmfifo(d) container_of(d, struct mlxbf_tmfifo_vdev, vdev)
+
+/* Free vrings of the FIFO device. */
+static void mlxbf_tmfifo_free_vrings(struct mlxbf_tmfifo *fifo,
+				     struct mlxbf_tmfifo_vdev *tm_vdev)
+{
+	struct mlxbf_tmfifo_vring *vring;
+	int i, size;
+
+	for (i = 0; i < ARRAY_SIZE(tm_vdev->vrings); i++) {
+		vring = &tm_vdev->vrings[i];
+		if (vring->va) {
+			size = vring_size(vring->num, vring->align);
+			dma_free_coherent(tm_vdev->vdev.dev.parent, size,
+					  vring->va, vring->dma);
+			vring->va = NULL;
+			if (vring->vq) {
+				vring_del_virtqueue(vring->vq);
+				vring->vq = NULL;
+			}
+		}
+	}
+}
+
+/* Allocate vrings for the FIFO. */
+static int mlxbf_tmfifo_alloc_vrings(struct mlxbf_tmfifo *fifo,
+				     struct mlxbf_tmfifo_vdev *tm_vdev)
+{
+	struct mlxbf_tmfifo_vring *vring;
+	struct device *dev;
+	dma_addr_t dma;
+	int i, size;
+	void *va;
+
+	for (i = 0; i < ARRAY_SIZE(tm_vdev->vrings); i++) {
+		vring = &tm_vdev->vrings[i];
+		vring->fifo = fifo;
+		vring->num = MLXBF_TMFIFO_VRING_SIZE;
+		vring->align = SMP_CACHE_BYTES;
+		vring->index = i;
+		vring->vdev_id = tm_vdev->vdev.id.device;
+		vring->drop_desc.len = VRING_DROP_DESC_MAX_LEN;
+		dev = &tm_vdev->vdev.dev;
+
+		size = vring_size(vring->num, vring->align);
+		va = dma_alloc_coherent(dev->parent, size, &dma, GFP_KERNEL);
+		if (!va) {
+			mlxbf_tmfifo_free_vrings(fifo, tm_vdev);
+			dev_err(dev->parent, "dma_alloc_coherent failed\n");
+			return -ENOMEM;
+		}
+
+		vring->va = va;
+		vring->dma = dma;
+	}
+
+	return 0;
+}
+
+/* Disable interrupts of the FIFO device. */
+static void mlxbf_tmfifo_disable_irqs(struct mlxbf_tmfifo *fifo)
+{
+	int i, irq;
+
+	for (i = 0; i < MLXBF_TM_MAX_IRQ; i++) {
+		irq = fifo->irq_info[i].irq;
+		fifo->irq_info[i].irq = 0;
+		disable_irq(irq);
+	}
+}
+
+/* Interrupt handler. */
+static irqreturn_t mlxbf_tmfifo_irq_handler(int irq, void *arg)
+{
+	struct mlxbf_tmfifo_irq_info *irq_info = arg;
+
+	if (!test_and_set_bit(irq_info->index, &irq_info->fifo->pend_events))
+		schedule_work(&irq_info->fifo->work);
+
+	return IRQ_HANDLED;
+}
+
+/* Get the next packet descriptor from the vring. */
+static struct vring_desc *
+mlxbf_tmfifo_get_next_desc(struct mlxbf_tmfifo_vring *vring)
+{
+	const struct vring *vr = virtqueue_get_vring(vring->vq);
+	struct virtio_device *vdev = vring->vq->vdev;
+	unsigned int idx, head;
+
+	if (vring->next_avail == virtio16_to_cpu(vdev, vr->avail->idx))
+		return NULL;
+
+	/* Make sure 'avail->idx' is visible already. */
+	virtio_rmb(false);
+
+	idx = vring->next_avail % vr->num;
+	head = virtio16_to_cpu(vdev, vr->avail->ring[idx]);
+	if (WARN_ON(head >= vr->num))
+		return NULL;
+
+	vring->next_avail++;
+
+	return &vr->desc[head];
+}
+
+/* Release virtio descriptor. */
+static void mlxbf_tmfifo_release_desc(struct mlxbf_tmfifo_vring *vring,
+				      struct vring_desc *desc, u32 len)
+{
+	const struct vring *vr = virtqueue_get_vring(vring->vq);
+	struct virtio_device *vdev = vring->vq->vdev;
+	u16 idx, vr_idx;
+
+	vr_idx = virtio16_to_cpu(vdev, vr->used->idx);
+	idx = vr_idx % vr->num;
+	vr->used->ring[idx].id = cpu_to_virtio32(vdev, desc - vr->desc);
+	vr->used->ring[idx].len = cpu_to_virtio32(vdev, len);
+
+	/*
+	 * Virtio could poll and check the 'idx' to decide whether the desc is
+	 * done or not. Add a memory barrier here to make sure the update above
+	 * completes before updating the idx.
+	 */
+	virtio_mb(false);
+	vr->used->idx = cpu_to_virtio16(vdev, vr_idx + 1);
+}
+
+/* Get the total length of the descriptor chain. */
+static u32 mlxbf_tmfifo_get_pkt_len(struct mlxbf_tmfifo_vring *vring,
+				    struct vring_desc *desc)
+{
+	const struct vring *vr = virtqueue_get_vring(vring->vq);
+	struct virtio_device *vdev = vring->vq->vdev;
+	u32 len = 0, idx;
+
+	while (desc) {
+		len += virtio32_to_cpu(vdev, desc->len);
+		if (!(virtio16_to_cpu(vdev, desc->flags) & VRING_DESC_F_NEXT))
+			break;
+		idx = virtio16_to_cpu(vdev, desc->next);
+		desc = &vr->desc[idx];
+	}
+
+	return len;
+}
+
+static void mlxbf_tmfifo_release_pkt(struct mlxbf_tmfifo_vring *vring)
+{
+	struct vring_desc *desc_head;
+	u32 len = 0;
+
+	if (vring->desc_head) {
+		desc_head = vring->desc_head;
+		len = vring->pkt_len;
+	} else {
+		desc_head = mlxbf_tmfifo_get_next_desc(vring);
+		len = mlxbf_tmfifo_get_pkt_len(vring, desc_head);
+	}
+
+	if (desc_head)
+		mlxbf_tmfifo_release_desc(vring, desc_head, len);
+
+	vring->pkt_len = 0;
+	vring->desc = NULL;
+	vring->desc_head = NULL;
+}
+
+static void mlxbf_tmfifo_init_net_desc(struct mlxbf_tmfifo_vring *vring,
+				       struct vring_desc *desc, bool is_rx)
+{
+	struct virtio_device *vdev = vring->vq->vdev;
+	struct virtio_net_hdr *net_hdr;
+
+	net_hdr = phys_to_virt(virtio64_to_cpu(vdev, desc->addr));
+	memset(net_hdr, 0, sizeof(*net_hdr));
+}
+
+/* Get and initialize the next packet. */
+static struct vring_desc *
+mlxbf_tmfifo_get_next_pkt(struct mlxbf_tmfifo_vring *vring, bool is_rx)
+{
+	struct vring_desc *desc;
+
+	desc = mlxbf_tmfifo_get_next_desc(vring);
+	if (desc && is_rx && vring->vdev_id == VIRTIO_ID_NET)
+		mlxbf_tmfifo_init_net_desc(vring, desc, is_rx);
+
+	vring->desc_head = desc;
+	vring->desc = desc;
+
+	return desc;
+}
+
+/* House-keeping timer. */
+static void mlxbf_tmfifo_timer(struct timer_list *t)
+{
+	struct mlxbf_tmfifo *fifo = container_of(t, struct mlxbf_tmfifo, timer);
+	int rx, tx;
+
+	rx = !test_and_set_bit(MLXBF_TM_RX_HWM_IRQ, &fifo->pend_events);
+	tx = !test_and_set_bit(MLXBF_TM_TX_LWM_IRQ, &fifo->pend_events);
+
+	if (rx || tx)
+		schedule_work(&fifo->work);
+
+	mod_timer(&fifo->timer, jiffies + MLXBF_TMFIFO_TIMER_INTERVAL);
+}
+
+/* Copy one console packet into the output buffer. */
+static void mlxbf_tmfifo_console_output_one(struct mlxbf_tmfifo_vdev *cons,
+					    struct mlxbf_tmfifo_vring *vring,
+					    struct vring_desc *desc)
+{
+	const struct vring *vr = virtqueue_get_vring(vring->vq);
+	struct virtio_device *vdev = &cons->vdev;
+	u32 len, idx, seg;
+	void *addr;
+
+	while (desc) {
+		addr = phys_to_virt(virtio64_to_cpu(vdev, desc->addr));
+		len = virtio32_to_cpu(vdev, desc->len);
+
+		seg = CIRC_SPACE_TO_END(cons->tx_buf.head, cons->tx_buf.tail,
+					MLXBF_TMFIFO_CON_TX_BUF_SIZE);
+		if (len <= seg) {
+			memcpy(cons->tx_buf.buf + cons->tx_buf.head, addr, len);
+		} else {
+			memcpy(cons->tx_buf.buf + cons->tx_buf.head, addr, seg);
+			addr += seg;
+			memcpy(cons->tx_buf.buf, addr, len - seg);
+		}
+		cons->tx_buf.head = (cons->tx_buf.head + len) %
+			MLXBF_TMFIFO_CON_TX_BUF_SIZE;
+
+		if (!(virtio16_to_cpu(vdev, desc->flags) & VRING_DESC_F_NEXT))
+			break;
+		idx = virtio16_to_cpu(vdev, desc->next);
+		desc = &vr->desc[idx];
+	}
+}
+
+/* Copy console data into the output buffer. */
+static void mlxbf_tmfifo_console_output(struct mlxbf_tmfifo_vdev *cons,
+					struct mlxbf_tmfifo_vring *vring)
+{
+	struct vring_desc *desc;
+	u32 len, avail;
+
+	desc = mlxbf_tmfifo_get_next_desc(vring);
+	while (desc) {
+		/* Release the packet if not enough space. */
+		len = mlxbf_tmfifo_get_pkt_len(vring, desc);
+		avail = CIRC_SPACE(cons->tx_buf.head, cons->tx_buf.tail,
+				   MLXBF_TMFIFO_CON_TX_BUF_SIZE);
+		if (len + MLXBF_TMFIFO_CON_TX_BUF_RSV_SIZE > avail) {
+			mlxbf_tmfifo_release_desc(vring, desc, len);
+			break;
+		}
+
+		mlxbf_tmfifo_console_output_one(cons, vring, desc);
+		mlxbf_tmfifo_release_desc(vring, desc, len);
+		desc = mlxbf_tmfifo_get_next_desc(vring);
+	}
+}
+
+/* Get the number of available words in Rx FIFO for receiving. */
+static int mlxbf_tmfifo_get_rx_avail(struct mlxbf_tmfifo *fifo)
+{
+	u64 sts;
+
+	sts = readq(fifo->rx_base + MLXBF_TMFIFO_RX_STS);
+	return FIELD_GET(MLXBF_TMFIFO_RX_STS__COUNT_MASK, sts);
+}
+
+/* Get the number of available words in the TmFifo for sending. */
+static int mlxbf_tmfifo_get_tx_avail(struct mlxbf_tmfifo *fifo, int vdev_id)
+{
+	int tx_reserve;
+	u32 count;
+	u64 sts;
+
+	/* Reserve some room in FIFO for console messages. */
+	if (vdev_id == VIRTIO_ID_NET)
+		tx_reserve = fifo->tx_fifo_size / MLXBF_TMFIFO_RESERVE_RATIO;
+	else
+		tx_reserve = 1;
+
+	sts = readq(fifo->tx_base + MLXBF_TMFIFO_TX_STS);
+	count = FIELD_GET(MLXBF_TMFIFO_TX_STS__COUNT_MASK, sts);
+	return fifo->tx_fifo_size - tx_reserve - count;
+}
+
+/* Console Tx (move data from the output buffer into the TmFifo). */
+static void mlxbf_tmfifo_console_tx(struct mlxbf_tmfifo *fifo, int avail)
+{
+	struct mlxbf_tmfifo_msg_hdr hdr;
+	struct mlxbf_tmfifo_vdev *cons;
+	unsigned long flags;
+	int size, seg;
+	void *addr;
+	u64 data;
+
+	/* Return if not enough space available. */
+	if (avail < MLXBF_TMFIFO_DATA_MIN_WORDS)
+		return;
+
+	cons = fifo->vdev[VIRTIO_ID_CONSOLE];
+	if (!cons || !cons->tx_buf.buf)
+		return;
+
+	/* Return if no data to send. */
+	size = CIRC_CNT(cons->tx_buf.head, cons->tx_buf.tail,
+			MLXBF_TMFIFO_CON_TX_BUF_SIZE);
+	if (size == 0)
+		return;
+
+	/* Adjust the size to available space. */
+	if (size + sizeof(hdr) > avail * sizeof(u64))
+		size = avail * sizeof(u64) - sizeof(hdr);
+
+	/* Write header. */
+	hdr.type = VIRTIO_ID_CONSOLE;
+	hdr.len = htons(size);
+	writeq(*(u64 *)&hdr, fifo->tx_base + MLXBF_TMFIFO_TX_DATA);
+
+	/* Use spin-lock to protect the 'cons->tx_buf'. */
+	spin_lock_irqsave(&fifo->spin_lock[0], flags);
+
+	while (size > 0) {
+		addr = cons->tx_buf.buf + cons->tx_buf.tail;
+
+		seg = CIRC_CNT_TO_END(cons->tx_buf.head, cons->tx_buf.tail,
+				      MLXBF_TMFIFO_CON_TX_BUF_SIZE);
+		if (seg >= sizeof(u64)) {
+			memcpy(&data, addr, sizeof(u64));
+		} else {
+			memcpy(&data, addr, seg);
+			memcpy((u8 *)&data + seg, cons->tx_buf.buf,
+			       sizeof(u64) - seg);
+		}
+		writeq(data, fifo->tx_base + MLXBF_TMFIFO_TX_DATA);
+
+		if (size >= sizeof(u64)) {
+			cons->tx_buf.tail = (cons->tx_buf.tail + sizeof(u64)) %
+				MLXBF_TMFIFO_CON_TX_BUF_SIZE;
+			size -= sizeof(u64);
+		} else {
+			cons->tx_buf.tail = (cons->tx_buf.tail + size) %
+				MLXBF_TMFIFO_CON_TX_BUF_SIZE;
+			size = 0;
+		}
+	}
+
+	spin_unlock_irqrestore(&fifo->spin_lock[0], flags);
+}
+
+/* Rx/Tx one word in the descriptor buffer. */
+static void mlxbf_tmfifo_rxtx_word(struct mlxbf_tmfifo_vring *vring,
+				   struct vring_desc *desc,
+				   bool is_rx, int len)
+{
+	struct virtio_device *vdev = vring->vq->vdev;
+	struct mlxbf_tmfifo *fifo = vring->fifo;
+	void *addr;
+	u64 data;
+
+	/* Get the buffer address of this desc. */
+	addr = phys_to_virt(virtio64_to_cpu(vdev, desc->addr));
+
+	/* Read a word from FIFO for Rx. */
+	if (is_rx)
+		data = readq(fifo->rx_base + MLXBF_TMFIFO_RX_DATA);
+
+	if (vring->cur_len + sizeof(u64) <= len) {
+		/* The whole word. */
+		if (is_rx) {
+			if (!IS_VRING_DROP(vring))
+				memcpy(addr + vring->cur_len, &data,
+				       sizeof(u64));
+		} else {
+			memcpy(&data, addr + vring->cur_len,
+			       sizeof(u64));
+		}
+		vring->cur_len += sizeof(u64);
+	} else {
+		/* Leftover bytes. */
+		if (is_rx) {
+			if (!IS_VRING_DROP(vring))
+				memcpy(addr + vring->cur_len, &data,
+				       len - vring->cur_len);
+		} else {
+			data = 0;
+			memcpy(&data, addr + vring->cur_len,
+			       len - vring->cur_len);
+		}
+		vring->cur_len = len;
+	}
+
+	/* Write the word into FIFO for Tx. */
+	if (!is_rx)
+		writeq(data, fifo->tx_base + MLXBF_TMFIFO_TX_DATA);
+}
+
+/*
+ * Rx/Tx packet header.
+ *
+ * In Rx case, the packet might be found to belong to a different vring since
+ * the TmFifo is shared by different services. In such case, the 'vring_change'
+ * flag is set.
+ */
+static void mlxbf_tmfifo_rxtx_header(struct mlxbf_tmfifo_vring *vring,
+				     struct vring_desc **desc,
+				     bool is_rx, bool *vring_change)
+{
+	struct mlxbf_tmfifo *fifo = vring->fifo;
+	struct virtio_net_config *config;
+	struct mlxbf_tmfifo_msg_hdr hdr;
+	int vdev_id, hdr_len;
+	bool drop_rx = false;
+
+	/* Read/Write packet header. */
+	if (is_rx) {
+		/* Drain one word from the FIFO. */
+		*(u64 *)&hdr = readq(fifo->rx_base + MLXBF_TMFIFO_RX_DATA);
+
+		/* Skip the length 0 packets (keepalive). */
+		if (hdr.len == 0)
+			return;
+
+		/* Check packet type. */
+		if (hdr.type == VIRTIO_ID_NET) {
+			vdev_id = VIRTIO_ID_NET;
+			hdr_len = sizeof(struct virtio_net_hdr);
+			config = &fifo->vdev[vdev_id]->config.net;
+			/* A legacy-only interface for now. */
+			if (ntohs(hdr.len) >
+			    __virtio16_to_cpu(virtio_legacy_is_little_endian(),
+					      config->mtu) +
+					      MLXBF_TMFIFO_NET_L2_OVERHEAD)
+				drop_rx = true;
+		} else {
+			vdev_id = VIRTIO_ID_CONSOLE;
+			hdr_len = 0;
+		}
+
+		/*
+		 * Check whether the new packet still belongs to this vring.
+		 * If not, update the pkt_len of the new vring.
+		 */
+		if (vdev_id != vring->vdev_id) {
+			struct mlxbf_tmfifo_vdev *tm_dev2 = fifo->vdev[vdev_id];
+
+			if (!tm_dev2)
+				return;
+			vring->desc = *desc;
+			vring = &tm_dev2->vrings[MLXBF_TMFIFO_VRING_RX];
+			*vring_change = true;
+		}
+
+		if (drop_rx && !IS_VRING_DROP(vring)) {
+			if (vring->desc_head)
+				mlxbf_tmfifo_release_pkt(vring);
+			*desc = &vring->drop_desc;
+			vring->desc_head = *desc;
+			vring->desc = *desc;
+		}
+
+		vring->pkt_len = ntohs(hdr.len) + hdr_len;
+	} else {
+		/* Network virtio has an extra header. */
+		hdr_len = (vring->vdev_id == VIRTIO_ID_NET) ?
+			   sizeof(struct virtio_net_hdr) : 0;
+		vring->pkt_len = mlxbf_tmfifo_get_pkt_len(vring, *desc);
+		hdr.type = (vring->vdev_id == VIRTIO_ID_NET) ?
+			    VIRTIO_ID_NET : VIRTIO_ID_CONSOLE;
+		hdr.len = htons(vring->pkt_len - hdr_len);
+		writeq(*(u64 *)&hdr, fifo->tx_base + MLXBF_TMFIFO_TX_DATA);
+	}
+
+	vring->cur_len = hdr_len;
+	vring->rem_len = vring->pkt_len;
+	fifo->vring[is_rx] = vring;
+}
+
+/*
+ * Rx/Tx one descriptor.
+ *
+ * Return true to indicate more data available.
+ */
+static bool mlxbf_tmfifo_rxtx_one_desc(struct mlxbf_tmfifo_vring *vring,
+				       bool is_rx, int *avail)
+{
+	const struct vring *vr = virtqueue_get_vring(vring->vq);
+	struct mlxbf_tmfifo *fifo = vring->fifo;
+	struct virtio_device *vdev;
+	bool vring_change = false;
+	struct vring_desc *desc;
+	unsigned long flags;
+	u32 len, idx;
+
+	vdev = &fifo->vdev[vring->vdev_id]->vdev;
+
+	/* Get the descriptor of the next packet. */
+	if (!vring->desc) {
+		desc = mlxbf_tmfifo_get_next_pkt(vring, is_rx);
+		if (!desc) {
+			/* Drop next Rx packet to avoid stuck. */
+			if (is_rx) {
+				desc = &vring->drop_desc;
+				vring->desc_head = desc;
+				vring->desc = desc;
+			} else {
+				return false;
+			}
+		}
+	} else {
+		desc = vring->desc;
+	}
+
+	/* Beginning of a packet. Start to Rx/Tx packet header. */
+	if (vring->pkt_len == 0) {
+		mlxbf_tmfifo_rxtx_header(vring, &desc, is_rx, &vring_change);
+		(*avail)--;
+
+		/* Return if new packet is for another ring. */
+		if (vring_change)
+			return false;
+		goto mlxbf_tmfifo_desc_done;
+	}
+
+	/* Get the length of this desc. */
+	len = virtio32_to_cpu(vdev, desc->len);
+	if (len > vring->rem_len)
+		len = vring->rem_len;
+
+	/* Rx/Tx one word (8 bytes) if not done. */
+	if (vring->cur_len < len) {
+		mlxbf_tmfifo_rxtx_word(vring, desc, is_rx, len);
+		(*avail)--;
+	}
+
+	/* Check again whether it's done. */
+	if (vring->cur_len == len) {
+		vring->cur_len = 0;
+		vring->rem_len -= len;
+
+		/* Get the next desc on the chain. */
+		if (!IS_VRING_DROP(vring) && vring->rem_len > 0 &&
+		    (virtio16_to_cpu(vdev, desc->flags) & VRING_DESC_F_NEXT)) {
+			idx = virtio16_to_cpu(vdev, desc->next);
+			desc = &vr->desc[idx];
+			goto mlxbf_tmfifo_desc_done;
+		}
+
+		/* Done and release the packet. */
+		desc = NULL;
+		fifo->vring[is_rx] = NULL;
+		if (!IS_VRING_DROP(vring)) {
+			mlxbf_tmfifo_release_pkt(vring);
+		} else {
+			vring->pkt_len = 0;
+			vring->desc_head = NULL;
+			vring->desc = NULL;
+			return false;
+		}
+
+		/*
+		 * Make sure the load/store are in order before
+		 * returning back to virtio.
+		 */
+		virtio_mb(false);
+
+		/* Notify upper layer that packet is done. */
+		spin_lock_irqsave(&fifo->spin_lock[is_rx], flags);
+		vring_interrupt(0, vring->vq);
+		spin_unlock_irqrestore(&fifo->spin_lock[is_rx], flags);
+	}
+
+mlxbf_tmfifo_desc_done:
+	/* Save the current desc. */
+	vring->desc = desc;
+
+	return true;
+}
+
+/* Rx & Tx processing of a queue. */
+static void mlxbf_tmfifo_rxtx(struct mlxbf_tmfifo_vring *vring, bool is_rx)
+{
+	int avail = 0, devid = vring->vdev_id;
+	struct mlxbf_tmfifo *fifo;
+	bool more;
+
+	fifo = vring->fifo;
+
+	/* Return if vdev is not ready. */
+	if (!fifo || !fifo->vdev[devid])
+		return;
+
+	/* Return if another vring is running. */
+	if (fifo->vring[is_rx] && fifo->vring[is_rx] != vring)
+		return;
+
+	/* Only handle console and network for now. */
+	if (WARN_ON(devid != VIRTIO_ID_NET && devid != VIRTIO_ID_CONSOLE))
+		return;
+
+	do {
+		/* Get available FIFO space. */
+		if (avail == 0) {
+			if (is_rx)
+				avail = mlxbf_tmfifo_get_rx_avail(fifo);
+			else
+				avail = mlxbf_tmfifo_get_tx_avail(fifo, devid);
+			if (avail <= 0)
+				break;
+		}
+
+		/* Console output always comes from the Tx buffer. */
+		if (!is_rx && devid == VIRTIO_ID_CONSOLE) {
+			mlxbf_tmfifo_console_tx(fifo, avail);
+			break;
+		}
+
+		/* Handle one descriptor. */
+		more = mlxbf_tmfifo_rxtx_one_desc(vring, is_rx, &avail);
+	} while (more);
+}
+
+/* Handle Rx or Tx queues. */
+static void mlxbf_tmfifo_work_rxtx(struct mlxbf_tmfifo *fifo, int queue_id,
+				   int irq_id, bool is_rx)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev;
+	struct mlxbf_tmfifo_vring *vring;
+	int i;
+
+	if (!test_and_clear_bit(irq_id, &fifo->pend_events) ||
+	    !fifo->irq_info[irq_id].irq)
+		return;
+
+	for (i = 0; i < MLXBF_TMFIFO_VDEV_MAX; i++) {
+		tm_vdev = fifo->vdev[i];
+		if (tm_vdev) {
+			vring = &tm_vdev->vrings[queue_id];
+			if (vring->vq)
+				mlxbf_tmfifo_rxtx(vring, is_rx);
+		}
+	}
+}
+
+/* Work handler for Rx and Tx case. */
+static void mlxbf_tmfifo_work_handler(struct work_struct *work)
+{
+	struct mlxbf_tmfifo *fifo;
+
+	fifo = container_of(work, struct mlxbf_tmfifo, work);
+	if (!fifo->is_ready)
+		return;
+
+	mutex_lock(&fifo->lock);
+
+	/* Tx (Send data to the TmFifo). */
+	mlxbf_tmfifo_work_rxtx(fifo, MLXBF_TMFIFO_VRING_TX,
+			       MLXBF_TM_TX_LWM_IRQ, false);
+
+	/* Rx (Receive data from the TmFifo). */
+	mlxbf_tmfifo_work_rxtx(fifo, MLXBF_TMFIFO_VRING_RX,
+			       MLXBF_TM_RX_HWM_IRQ, true);
+
+	mutex_unlock(&fifo->lock);
+}
+
+/* The notify function is called when new buffers are posted. */
+static bool mlxbf_tmfifo_virtio_notify(struct virtqueue *vq)
+{
+	struct mlxbf_tmfifo_vring *vring = vq->priv;
+	struct mlxbf_tmfifo_vdev *tm_vdev;
+	struct mlxbf_tmfifo *fifo;
+	unsigned long flags;
+
+	fifo = vring->fifo;
+
+	/*
+	 * Virtio maintains vrings in pairs, even number ring for Rx
+	 * and odd number ring for Tx.
+	 */
+	if (vring->index & BIT(0)) {
+		/*
+		 * Console could make blocking call with interrupts disabled.
+		 * In such case, the vring needs to be served right away. For
+		 * other cases, just set the TX LWM bit to start Tx in the
+		 * worker handler.
+		 */
+		if (vring->vdev_id == VIRTIO_ID_CONSOLE) {
+			spin_lock_irqsave(&fifo->spin_lock[0], flags);
+			tm_vdev = fifo->vdev[VIRTIO_ID_CONSOLE];
+			mlxbf_tmfifo_console_output(tm_vdev, vring);
+			spin_unlock_irqrestore(&fifo->spin_lock[0], flags);
+			set_bit(MLXBF_TM_TX_LWM_IRQ, &fifo->pend_events);
+		} else if (test_and_set_bit(MLXBF_TM_TX_LWM_IRQ,
+					    &fifo->pend_events)) {
+			return true;
+		}
+	} else {
+		if (test_and_set_bit(MLXBF_TM_RX_HWM_IRQ, &fifo->pend_events))
+			return true;
+	}
+
+	schedule_work(&fifo->work);
+
+	return true;
+}
+
+/* Get the array of feature bits for this device. */
+static u64 mlxbf_tmfifo_virtio_get_features(struct virtio_device *vdev)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+
+	return tm_vdev->features;
+}
+
+/* Confirm device features to use. */
+static int mlxbf_tmfifo_virtio_finalize_features(struct virtio_device *vdev)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+
+	tm_vdev->features = vdev->features;
+
+	return 0;
+}
+
+/* Free virtqueues found by find_vqs(). */
+static void mlxbf_tmfifo_virtio_del_vqs(struct virtio_device *vdev)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+	struct mlxbf_tmfifo_vring *vring;
+	struct virtqueue *vq;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tm_vdev->vrings); i++) {
+		vring = &tm_vdev->vrings[i];
+
+		/* Release the pending packet. */
+		if (vring->desc)
+			mlxbf_tmfifo_release_pkt(vring);
+		vq = vring->vq;
+		if (vq) {
+			vring->vq = NULL;
+			vring_del_virtqueue(vq);
+		}
+	}
+}
+
+/* Create and initialize the virtual queues. */
+static int mlxbf_tmfifo_virtio_find_vqs(struct virtio_device *vdev,
+					unsigned int nvqs,
+					struct virtqueue *vqs[],
+					vq_callback_t *callbacks[],
+					const char * const names[],
+					const bool *ctx,
+					struct irq_affinity *desc)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+	struct mlxbf_tmfifo_vring *vring;
+	struct virtqueue *vq;
+	int i, ret, size;
+
+	if (nvqs > ARRAY_SIZE(tm_vdev->vrings))
+		return -EINVAL;
+
+	for (i = 0; i < nvqs; ++i) {
+		if (!names[i]) {
+			ret = -EINVAL;
+			goto error;
+		}
+		vring = &tm_vdev->vrings[i];
+
+		/* zero vring */
+		size = vring_size(vring->num, vring->align);
+		memset(vring->va, 0, size);
+		vq = vring_new_virtqueue(i, vring->num, vring->align, vdev,
+					 false, false, vring->va,
+					 mlxbf_tmfifo_virtio_notify,
+					 callbacks[i], names[i]);
+		if (!vq) {
+			dev_err(&vdev->dev, "vring_new_virtqueue failed\n");
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		vq->num_max = vring->num;
+
+		vq->priv = vring;
+
+		/* Make vq update visible before using it. */
+		virtio_mb(false);
+
+		vqs[i] = vq;
+		vring->vq = vq;
+	}
+
+	return 0;
+
+error:
+	mlxbf_tmfifo_virtio_del_vqs(vdev);
+	return ret;
+}
+
+/* Read the status byte. */
+static u8 mlxbf_tmfifo_virtio_get_status(struct virtio_device *vdev)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+
+	return tm_vdev->status;
+}
+
+/* Write the status byte. */
+static void mlxbf_tmfifo_virtio_set_status(struct virtio_device *vdev,
+					   u8 status)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+
+	tm_vdev->status = status;
+}
+
+/* Reset the device. Not much here for now. */
+static void mlxbf_tmfifo_virtio_reset(struct virtio_device *vdev)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+
+	tm_vdev->status = 0;
+}
+
+/* Read the value of a configuration field. */
+static void mlxbf_tmfifo_virtio_get(struct virtio_device *vdev,
+				    unsigned int offset,
+				    void *buf,
+				    unsigned int len)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+
+	if ((u64)offset + len > sizeof(tm_vdev->config))
+		return;
+
+	memcpy(buf, (u8 *)&tm_vdev->config + offset, len);
+}
+
+/* Write the value of a configuration field. */
+static void mlxbf_tmfifo_virtio_set(struct virtio_device *vdev,
+				    unsigned int offset,
+				    const void *buf,
+				    unsigned int len)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+
+	if ((u64)offset + len > sizeof(tm_vdev->config))
+		return;
+
+	memcpy((u8 *)&tm_vdev->config + offset, buf, len);
+}
+
+static void tmfifo_virtio_dev_release(struct device *device)
+{
+	struct virtio_device *vdev =
+			container_of(device, struct virtio_device, dev);
+	struct mlxbf_tmfifo_vdev *tm_vdev = mlxbf_vdev_to_tmfifo(vdev);
+
+	kfree(tm_vdev);
+}
+
+/* Virtio config operations. */
+static const struct virtio_config_ops mlxbf_tmfifo_virtio_config_ops = {
+	.get_features = mlxbf_tmfifo_virtio_get_features,
+	.finalize_features = mlxbf_tmfifo_virtio_finalize_features,
+	.find_vqs = mlxbf_tmfifo_virtio_find_vqs,
+	.del_vqs = mlxbf_tmfifo_virtio_del_vqs,
+	.reset = mlxbf_tmfifo_virtio_reset,
+	.set_status = mlxbf_tmfifo_virtio_set_status,
+	.get_status = mlxbf_tmfifo_virtio_get_status,
+	.get = mlxbf_tmfifo_virtio_get,
+	.set = mlxbf_tmfifo_virtio_set,
+};
+
+/* Create vdev for the FIFO. */
+static int mlxbf_tmfifo_create_vdev(struct device *dev,
+				    struct mlxbf_tmfifo *fifo,
+				    int vdev_id, u64 features,
+				    void *config, u32 size)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev, *reg_dev = NULL;
+	int ret;
+
+	mutex_lock(&fifo->lock);
+
+	tm_vdev = fifo->vdev[vdev_id];
+	if (tm_vdev) {
+		dev_err(dev, "vdev %d already exists\n", vdev_id);
+		ret = -EEXIST;
+		goto fail;
+	}
+
+	tm_vdev = kzalloc(sizeof(*tm_vdev), GFP_KERNEL);
+	if (!tm_vdev) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	tm_vdev->vdev.id.device = vdev_id;
+	tm_vdev->vdev.config = &mlxbf_tmfifo_virtio_config_ops;
+	tm_vdev->vdev.dev.parent = dev;
+	tm_vdev->vdev.dev.release = tmfifo_virtio_dev_release;
+	tm_vdev->features = features;
+	if (config)
+		memcpy(&tm_vdev->config, config, size);
+
+	if (mlxbf_tmfifo_alloc_vrings(fifo, tm_vdev)) {
+		dev_err(dev, "unable to allocate vring\n");
+		ret = -ENOMEM;
+		goto vdev_fail;
+	}
+
+	/* Allocate an output buffer for the console device. */
+	if (vdev_id == VIRTIO_ID_CONSOLE)
+		tm_vdev->tx_buf.buf = devm_kmalloc(dev,
+						   MLXBF_TMFIFO_CON_TX_BUF_SIZE,
+						   GFP_KERNEL);
+	fifo->vdev[vdev_id] = tm_vdev;
+
+	/* Register the virtio device. */
+	ret = register_virtio_device(&tm_vdev->vdev);
+	reg_dev = tm_vdev;
+	if (ret) {
+		dev_err(dev, "register_virtio_device failed\n");
+		goto vdev_fail;
+	}
+
+	mutex_unlock(&fifo->lock);
+	return 0;
+
+vdev_fail:
+	mlxbf_tmfifo_free_vrings(fifo, tm_vdev);
+	fifo->vdev[vdev_id] = NULL;
+	if (reg_dev)
+		put_device(&tm_vdev->vdev.dev);
+	else
+		kfree(tm_vdev);
+fail:
+	mutex_unlock(&fifo->lock);
+	return ret;
+}
+
+/* Delete vdev for the FIFO. */
+static int mlxbf_tmfifo_delete_vdev(struct mlxbf_tmfifo *fifo, int vdev_id)
+{
+	struct mlxbf_tmfifo_vdev *tm_vdev;
+
+	mutex_lock(&fifo->lock);
+
+	/* Unregister vdev. */
+	tm_vdev = fifo->vdev[vdev_id];
+	if (tm_vdev) {
+		unregister_virtio_device(&tm_vdev->vdev);
+		mlxbf_tmfifo_free_vrings(fifo, tm_vdev);
+		fifo->vdev[vdev_id] = NULL;
+	}
+
+	mutex_unlock(&fifo->lock);
+
+	return 0;
+}
+
+/* Read the configured network MAC address from efi variable. */
+static void mlxbf_tmfifo_get_cfg_mac(u8 *mac)
+{
+	efi_guid_t guid = EFI_GLOBAL_VARIABLE_GUID;
+	unsigned long size = ETH_ALEN;
+	u8 buf[ETH_ALEN];
+	efi_status_t rc;
+
+	rc = efi.get_variable(mlxbf_tmfifo_efi_name, &guid, NULL, &size, buf);
+	if (rc == EFI_SUCCESS && size == ETH_ALEN)
+		ether_addr_copy(mac, buf);
+	else
+		ether_addr_copy(mac, mlxbf_tmfifo_net_default_mac);
+}
+
+/* Set TmFifo thresolds which is used to trigger interrupts. */
+static void mlxbf_tmfifo_set_threshold(struct mlxbf_tmfifo *fifo)
+{
+	u64 ctl;
+
+	/* Get Tx FIFO size and set the low/high watermark. */
+	ctl = readq(fifo->tx_base + MLXBF_TMFIFO_TX_CTL);
+	fifo->tx_fifo_size =
+		FIELD_GET(MLXBF_TMFIFO_TX_CTL__MAX_ENTRIES_MASK, ctl);
+	ctl = (ctl & ~MLXBF_TMFIFO_TX_CTL__LWM_MASK) |
+		FIELD_PREP(MLXBF_TMFIFO_TX_CTL__LWM_MASK,
+			   fifo->tx_fifo_size / 2);
+	ctl = (ctl & ~MLXBF_TMFIFO_TX_CTL__HWM_MASK) |
+		FIELD_PREP(MLXBF_TMFIFO_TX_CTL__HWM_MASK,
+			   fifo->tx_fifo_size - 1);
+	writeq(ctl, fifo->tx_base + MLXBF_TMFIFO_TX_CTL);
+
+	/* Get Rx FIFO size and set the low/high watermark. */
+	ctl = readq(fifo->rx_base + MLXBF_TMFIFO_RX_CTL);
+	fifo->rx_fifo_size =
+		FIELD_GET(MLXBF_TMFIFO_RX_CTL__MAX_ENTRIES_MASK, ctl);
+	ctl = (ctl & ~MLXBF_TMFIFO_RX_CTL__LWM_MASK) |
+		FIELD_PREP(MLXBF_TMFIFO_RX_CTL__LWM_MASK, 0);
+	ctl = (ctl & ~MLXBF_TMFIFO_RX_CTL__HWM_MASK) |
+		FIELD_PREP(MLXBF_TMFIFO_RX_CTL__HWM_MASK, 1);
+	writeq(ctl, fifo->rx_base + MLXBF_TMFIFO_RX_CTL);
+}
+
+static void mlxbf_tmfifo_cleanup(struct mlxbf_tmfifo *fifo)
+{
+	int i;
+
+	fifo->is_ready = false;
+	del_timer_sync(&fifo->timer);
+	mlxbf_tmfifo_disable_irqs(fifo);
+	cancel_work_sync(&fifo->work);
+	for (i = 0; i < MLXBF_TMFIFO_VDEV_MAX; i++)
+		mlxbf_tmfifo_delete_vdev(fifo, i);
+}
+
+/* Probe the TMFIFO. */
+static int mlxbf_tmfifo_probe(struct platform_device *pdev)
+{
+	struct virtio_net_config net_config;
+	struct device *dev = &pdev->dev;
+	struct mlxbf_tmfifo *fifo;
+	int i, rc;
+
+	fifo = devm_kzalloc(dev, sizeof(*fifo), GFP_KERNEL);
+	if (!fifo)
+		return -ENOMEM;
+
+	spin_lock_init(&fifo->spin_lock[0]);
+	spin_lock_init(&fifo->spin_lock[1]);
+	INIT_WORK(&fifo->work, mlxbf_tmfifo_work_handler);
+	mutex_init(&fifo->lock);
+
+	/* Get the resource of the Rx FIFO. */
+	fifo->rx_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(fifo->rx_base))
+		return PTR_ERR(fifo->rx_base);
+
+	/* Get the resource of the Tx FIFO. */
+	fifo->tx_base = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(fifo->tx_base))
+		return PTR_ERR(fifo->tx_base);
+
+	platform_set_drvdata(pdev, fifo);
+
+	timer_setup(&fifo->timer, mlxbf_tmfifo_timer, 0);
+
+	for (i = 0; i < MLXBF_TM_MAX_IRQ; i++) {
+		fifo->irq_info[i].index = i;
+		fifo->irq_info[i].fifo = fifo;
+		fifo->irq_info[i].irq = platform_get_irq(pdev, i);
+		rc = devm_request_irq(dev, fifo->irq_info[i].irq,
+				      mlxbf_tmfifo_irq_handler, 0,
+				      "tmfifo", &fifo->irq_info[i]);
+		if (rc) {
+			dev_err(dev, "devm_request_irq failed\n");
+			fifo->irq_info[i].irq = 0;
+			return rc;
+		}
+	}
+
+	mlxbf_tmfifo_set_threshold(fifo);
+
+	/* Create the console vdev. */
+	rc = mlxbf_tmfifo_create_vdev(dev, fifo, VIRTIO_ID_CONSOLE, 0, NULL, 0);
+	if (rc)
+		goto fail;
+
+	/* Create the network vdev. */
+	memset(&net_config, 0, sizeof(net_config));
+
+	/* A legacy-only interface for now. */
+	net_config.mtu = __cpu_to_virtio16(virtio_legacy_is_little_endian(),
+					   ETH_DATA_LEN);
+	net_config.status = __cpu_to_virtio16(virtio_legacy_is_little_endian(),
+					      VIRTIO_NET_S_LINK_UP);
+	mlxbf_tmfifo_get_cfg_mac(net_config.mac);
+	rc = mlxbf_tmfifo_create_vdev(dev, fifo, VIRTIO_ID_NET,
+				      MLXBF_TMFIFO_NET_FEATURES, &net_config,
+				      sizeof(net_config));
+	if (rc)
+		goto fail;
+
+	mod_timer(&fifo->timer, jiffies + MLXBF_TMFIFO_TIMER_INTERVAL);
+
+	/* Make all updates visible before setting the 'is_ready' flag. */
+	virtio_mb(false);
+
+	fifo->is_ready = true;
+	return 0;
+
+fail:
+	mlxbf_tmfifo_cleanup(fifo);
+	return rc;
+}
+
+/* Device remove function. */
+static int mlxbf_tmfifo_remove(struct platform_device *pdev)
+{
+	struct mlxbf_tmfifo *fifo = platform_get_drvdata(pdev);
+
+	mlxbf_tmfifo_cleanup(fifo);
+
+	return 0;
+}
+
+static const struct acpi_device_id mlxbf_tmfifo_acpi_match[] = {
+	{ "MLNXBF01", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, mlxbf_tmfifo_acpi_match);
+
+static struct platform_driver mlxbf_tmfifo_driver = {
+	.probe = mlxbf_tmfifo_probe,
+	.remove = mlxbf_tmfifo_remove,
+	.driver = {
+		.name = "bf-tmfifo",
+		.acpi_match_table = mlxbf_tmfifo_acpi_match,
+	},
+};
+
+module_platform_driver(mlxbf_tmfifo_driver);
+
+MODULE_DESCRIPTION("Mellanox BlueField SoC TmFifo Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Mellanox Technologies");