net/ipc_router/ipc_router_fifo_xprt.c - kernel/msm-4.9 - Gitiles

 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2018, The Linux Foundation. All rights reserved.
  */

 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/ipc_router_xprt.h>
 #include <linux/io.h>
 #include <linux/of_device.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/sched.h>
 #include <microvisor/microvisor.h>

 #define MODULE_NAME "ipc_router_fifo_xprt"
 #define XPRT_NAME_LEN 32

 #define FIFO_MAGIC_KEY 0x24495043 /* "$IPC" */
 #define FIFO_SIZE 0x4000
 #define FIFO_0_START 0x1000
 #define FIFO_1_START (FIFO_0_START + FIFO_SIZE)
 #define FIFO_MAGIC_IDX 0x0
 #define TAIL_0_IDX 0x1
 #define HEAD_0_IDX 0x2
 #define TAIL_1_IDX 0x3
 #define HEAD_1_IDX 0x4

 struct msm_ipc_pipe {
 	__le32 *tail;
 	__le32 *head;

 	void *fifo;
 	size_t length;
 };

 /**
  * ipcr_fifo_xprt - IPC Router's FIFO XPRT structure
  * @xprt: IPC Router XPRT structure to contain XPRT specific info.
  * @tx_pipe: TX FIFO specific info.
  * @rx_pipe: RX FIFO specific info.
  * @fifo_xprt_wq: Workqueue to queue read & other XPRT related works.
  * @in_pkt: Pointer to any partially read packet.
  * @read_work: Read Work to perform read operation from SMD.
  * @sft_close_complete: Variable to indicate completion of SSR handling
  *                      by IPC Router.
  * @xprt_version: IPC Router header version supported by this XPRT.
  * @driver: Platform drivers register by this XPRT.
  * @xprt_name: Name of the XPRT to be registered with IPC Router.
  */
 struct ipcr_fifo_xprt {
 	struct msm_ipc_router_xprt xprt;
 	struct msm_ipc_pipe tx_pipe;
 	struct msm_ipc_pipe rx_pipe;
 	struct workqueue_struct *xprt_wq;
 	struct rr_packet *in_pkt;
 	struct delayed_work read_work;
 	struct completion sft_close_complete;
 	unsigned int xprt_version;
 	struct platform_driver driver;
 	char xprt_name[XPRT_NAME_LEN];
 	void *fifo_base;
 	size_t fifo_size;
 	int tx_fifo_idx;
 	okl4_kcap_t kcap;
 };

 static void xprt_read_data(struct work_struct *work);
 static void ipcr_fifo_raise_virq(struct ipcr_fifo_xprt *xprtp);

 static size_t fifo_rx_avail(struct msm_ipc_pipe *pipe)
 {
 	u32 head;
 	u32 tail;

 	head = le32_to_cpu(*pipe->head);
 	tail = le32_to_cpu(*pipe->tail);

 	if (head < tail)
 		return pipe->length - tail + head;

 	return head - tail;
 }

 static void fifo_rx_peak(struct msm_ipc_pipe *pipe,
 			 void *data, unsigned int offset, size_t count)
 {
 	size_t len;
 	u32 tail;

 	tail = le32_to_cpu(*pipe->tail);
 	tail += offset;
 	if (tail >= pipe->length)
 		tail -= pipe->length;

 	len = min_t(size_t, count, pipe->length - tail);
 	if (len)
 		memcpy_fromio(data, pipe->fifo + tail, len);

 	if (len != count)
 		memcpy_fromio(data + len, pipe->fifo, (count - len));
 }

 static void fifo_rx_advance(struct msm_ipc_pipe *pipe, size_t count)
 {
 	u32 tail;

 	tail = le32_to_cpu(*pipe->tail);

 	tail += count;
 	if (tail > pipe->length)
 		tail -= pipe->length;

 	*pipe->tail = cpu_to_le32(tail);
 }

 static size_t fifo_tx_avail(struct msm_ipc_pipe *pipe)
 {
 	u32 head;
 	u32 tail;
 	u32 avail;

 	 head = le32_to_cpu(*pipe->head);
 	 tail = le32_to_cpu(*pipe->tail);

 	if (tail <= head)
 		avail = pipe->length - head + tail;
 	else
 		avail = tail - head;

 	return avail;
 }

 static void fifo_tx_write(struct msm_ipc_pipe *pipe,
 			  const void *data, size_t count)
 {
 	size_t len;
 	u32 head;

 	head = le32_to_cpu(*pipe->head);

 	len = min_t(size_t, count, pipe->length - head);
 	if (len)
 		memcpy_toio(pipe->fifo + head, data, len);

 	if (len != count)
 		memcpy_toio(pipe->fifo, data + len, count - len);

 	head += count;
 	if (head >= pipe->length)
 		head -= pipe->length;

 	/* Ensure ordering of fifo and head update */
 	wmb();

 	*pipe->head = cpu_to_le32(head);
 }

 /**
  * set_xprt_version() - Set IPC Router header version in the transport
  * @xprt: Reference to the transport structure.
  * @version: The version to be set in transport.
  */
 static void set_xprt_version(struct msm_ipc_router_xprt *xprt,
 			     unsigned int version)
 {
 	struct ipcr_fifo_xprt *xprtp;

 	if (!xprt)
 		return;
 	xprtp = container_of(xprt, struct ipcr_fifo_xprt, xprt);
 	xprtp->xprt_version = version;
 }

 static int get_xprt_version(struct msm_ipc_router_xprt *xprt)
 {
 	struct ipcr_fifo_xprt *xprtp;

 	if (!xprt)
 		return -EINVAL;
 	xprtp = container_of(xprt, struct ipcr_fifo_xprt, xprt);
 	return (int)xprtp->xprt_version;
 }

 static int get_xprt_option(struct msm_ipc_router_xprt *xprt)
 {
 	/* fragmented data is NOT supported */
 	return 0;
 }

 static int xprt_close(struct msm_ipc_router_xprt *xprt)
 {
 	return 0;
 }

 static void xprt_sft_close_done(struct msm_ipc_router_xprt *xprt)
 {
 	struct ipcr_fifo_xprt *xprtp;

 	if (!xprt)
 		return;

 	xprtp = container_of(xprt, struct ipcr_fifo_xprt, xprt);
 	complete_all(&xprtp->sft_close_complete);
 }

 static int xprt_write(void *data, uint32_t len,
 		      struct msm_ipc_router_xprt *xprt)
 {
 	struct rr_packet *pkt = (struct rr_packet *)data;
 	struct sk_buff *skb;
 	struct ipcr_fifo_xprt *xprtp;

 	xprtp = container_of(xprt, struct ipcr_fifo_xprt, xprt);

 	if (!pkt)
 		return -EINVAL;

 	if (!len || pkt->length != len)
 		return -EINVAL;

 	/* TODO: FIFO write : check if we can write full packet at one shot */
 	if (skb_queue_len(pkt->pkt_fragment_q) != 1) {
 		pr_err("IPC router core is given fragmented data\n");
 		return -EINVAL;
 	}
 	if (fifo_tx_avail(&xprtp->tx_pipe) < len) {
 		pr_err("No Space in FIFO\n");
 		return -EAGAIN;
 	}

 	skb_queue_walk(pkt->pkt_fragment_q, skb) {
 		fifo_tx_write(&xprtp->tx_pipe, skb->data, skb->len);
 	}

 	ipcr_fifo_raise_virq(xprtp);

 	return len;
 }

 static void xprt_read_data(struct work_struct *work)
 {
 	void *data;
 	size_t hdr_len;
 	size_t rx_avail;
 	size_t pkt_len;
 	struct rr_header_v1 hdr;
 	struct sk_buff *ipc_rtr_pkt;
 	struct ipcr_fifo_xprt *xprtp;
 	struct delayed_work *rwork = to_delayed_work(work);

 	xprtp = container_of(rwork, struct ipcr_fifo_xprt, read_work);

 	hdr_len = sizeof(struct rr_header_v1);
 	while (1) {
 		rx_avail = fifo_rx_avail(&xprtp->rx_pipe);
 		if (!rx_avail)
 			break;

 		fifo_rx_peak(&xprtp->rx_pipe, &hdr, 0, hdr_len);
 		pkt_len = ipc_router_peek_pkt_size((char *)&hdr);

 		if (pkt_len < 0) {
 			pr_err("%s invalid pkt_len %zu\n", __func__, pkt_len);
 			break;
 		}
 		if (!xprtp->in_pkt) {
 			xprtp->in_pkt = create_pkt(NULL);
 			if (!xprtp->in_pkt)
 				break;
 		}
 		ipc_rtr_pkt = alloc_skb(pkt_len, GFP_KERNEL);
 		if (!ipc_rtr_pkt) {
 			release_pkt(xprtp->in_pkt);
 			xprtp->in_pkt = NULL;
 			break;
 		}
 		data = skb_put(ipc_rtr_pkt, pkt_len);
 		do {
 			rx_avail = fifo_rx_avail(&xprtp->rx_pipe);
 			if (rx_avail >= pkt_len) {
 				fifo_rx_peak(&xprtp->rx_pipe, data, 0, pkt_len);
 				fifo_rx_advance(&xprtp->rx_pipe, pkt_len);
 				break;
 			}
 			pr_debug("%s wait for FULL PKT [avail: len][%zu:%zu]\n",
 				 __func__, rx_avail, pkt_len);
 			/* wait for complete packet written into FIFO */
 			msleep(20);
 		} while (1);

 		skb_queue_tail(xprtp->in_pkt->pkt_fragment_q, ipc_rtr_pkt);
 		xprtp->in_pkt->length = pkt_len;
 		msm_ipc_router_xprt_notify(&xprtp->xprt,
 					   IPC_ROUTER_XPRT_EVENT_DATA,
 					   (void *)xprtp->in_pkt);
 		release_pkt(xprtp->in_pkt);
 		xprtp->in_pkt = NULL;
 	}
 }

 static void ipcr_fifo_raise_virq(struct ipcr_fifo_xprt *xprtp)
 {
 	okl4_error_t err;
 	unsigned long payload = 0xffff;

 	err = _okl4_sys_vinterrupt_raise(xprtp->kcap, payload);
 }

 static irqreturn_t ipcr_fifo_virq_handler(int irq, void *dev_id)
 {
 	struct ipcr_fifo_xprt *xprtp = dev_id;

 	queue_delayed_work(xprtp->xprt_wq, &xprtp->read_work, 0);
 	return IRQ_HANDLED;
 }

 /**
  * ipcr_fifo_config_init() - init FIFO xprt configs
  *
  * @return: 0 on success, standard Linux error codes on error.
  *
  * This function is called to initialize the FIFO XPRT pointer with
  * the FIFO XPRT configurations either from device tree or static arrays.
  */
 static int ipcr_fifo_config_init(struct ipcr_fifo_xprt *xprtp)
 {
 	__le32 *descs;

 	descs = xprtp->fifo_base;
 	descs[FIFO_MAGIC_IDX] = FIFO_MAGIC_KEY;

 	if (xprtp->tx_fifo_idx) {
 		xprtp->tx_pipe.tail = &descs[TAIL_0_IDX];
 		xprtp->tx_pipe.head = &descs[HEAD_0_IDX];
 		xprtp->tx_pipe.fifo = xprtp->fifo_base + FIFO_0_START;
 		xprtp->tx_pipe.length = FIFO_SIZE;

 		xprtp->rx_pipe.tail = &descs[TAIL_1_IDX];
 		xprtp->rx_pipe.head = &descs[HEAD_1_IDX];
 		xprtp->rx_pipe.fifo = xprtp->fifo_base + FIFO_1_START;
 		xprtp->rx_pipe.length = FIFO_SIZE;
 	} else {
 		xprtp->tx_pipe.tail = &descs[TAIL_1_IDX];
 		xprtp->tx_pipe.head = &descs[HEAD_1_IDX];
 		xprtp->tx_pipe.fifo = xprtp->fifo_base + FIFO_1_START;
 		xprtp->tx_pipe.length = FIFO_SIZE;

 		xprtp->rx_pipe.tail = &descs[TAIL_0_IDX];
 		xprtp->rx_pipe.head = &descs[HEAD_0_IDX];
 		xprtp->rx_pipe.fifo = xprtp->fifo_base + FIFO_0_START;
 		xprtp->rx_pipe.length = FIFO_SIZE;
 	}

 	/* Reset respective index */
 	*xprtp->tx_pipe.head = 0;
 	*xprtp->rx_pipe.tail = 0;

 	xprtp->xprt.link_id = 1;
 	xprtp->xprt_version = 1;

 	strlcpy(xprtp->xprt_name, "IPCR_FIFO_XPRT", XPRT_NAME_LEN);
 	xprtp->xprt.name = xprtp->xprt_name;

 	xprtp->xprt.set_version = set_xprt_version;
 	xprtp->xprt.get_version = get_xprt_version;
 	xprtp->xprt.get_option = get_xprt_option;
 	xprtp->xprt.read_avail = NULL;
 	xprtp->xprt.read = NULL;
 	xprtp->xprt.write_avail = NULL;
 	xprtp->xprt.write = xprt_write;
 	xprtp->xprt.close = xprt_close;
 	xprtp->xprt.sft_close_done = xprt_sft_close_done;
 	xprtp->xprt.priv = NULL;

 	xprtp->in_pkt = NULL;
 	xprtp->xprt_wq = create_singlethread_workqueue(xprtp->xprt_name);
 	if (!xprtp->xprt_wq)
 		return -EFAULT;

 	INIT_DELAYED_WORK(&xprtp->read_work, xprt_read_data);

 	msm_ipc_router_xprt_notify(&xprtp->xprt,
 				   IPC_ROUTER_XPRT_EVENT_OPEN,
 				   NULL);

 	if (fifo_rx_avail(&xprtp->rx_pipe))
 		queue_delayed_work(xprtp->xprt_wq, &xprtp->read_work, 0);

 	return 0;
 }

 /**
  * ipcr_fifo_xprt_probe() - Probe an FIFO xprt
  *
  * @pdev: Platform device corresponding to FIFO xprt.
  *
  * @return: 0 on success, standard Linux error codes on error.
  *
  * This function is called when the underlying device tree driver registers
  * a platform device, mapped to an FIFO transport.
  */
 static int ipcr_fifo_xprt_probe(struct platform_device *pdev)
 {
 	int irq;
 	int ret;
 	struct resource *r;
 	struct device *parent;
 	struct ipcr_fifo_xprt *xprtp;
 	struct device_node *ipc_irq_np;
 	struct device_node *ipc_shm_np;
 	struct platform_device *ipc_shm_dev;

 	xprtp = devm_kzalloc(&pdev->dev, sizeof(*xprtp), GFP_KERNEL);
 	if (IS_ERR_OR_NULL(xprtp))
 		return -ENOMEM;

 	parent = &pdev->dev;
 	ipc_irq_np = parent->of_node;

 	irq = platform_get_irq(pdev, 0);

 	if (irq >= 0) {
 		ret = devm_request_irq(parent, irq, ipcr_fifo_virq_handler,
 				       IRQF_TRIGGER_RISING, dev_name(parent),
 				       xprtp);
 		if (ret < 0)
 			return -ENODEV;
 	}

 	/* this kcap is required to raise VIRQ */
 	ret = of_property_read_u32(ipc_irq_np, "reg", &xprtp->kcap);
 	if (ret < 0)
 		return -ENODEV;

 	ipc_shm_np = of_parse_phandle(ipc_irq_np, "qcom,ipc-shm", 0);
 	if (!ipc_shm_np)
 		return -ENODEV;

 	ipc_shm_dev = of_find_device_by_node(ipc_shm_np);
 	if (!ipc_shm_dev)
 		return -ENODEV;

 	r = platform_get_resource(ipc_shm_dev, IORESOURCE_MEM, 0);
 	if (!r) {
 		pr_err("%s failed to get shared FIFO\n", __func__);
 		return -ENODEV;
 	}

 	xprtp->tx_fifo_idx = of_property_read_bool(ipc_shm_np,
 						   "qcom,tx-is-first");

 	xprtp->fifo_size = resource_size(r);
 	xprtp->fifo_base = devm_ioremap_nocache(&pdev->dev, r->start,
 						resource_size(r));
 	if (!xprtp->fifo_base) {
 		pr_err("%s ioreamp_nocache() failed\n", __func__);
 		return -ENOMEM;
 	}

 	ret = ipcr_fifo_config_init(xprtp);
 	if (ret) {
 		IPC_RTR_ERR("%s init failed ret[%d]\n", __func__, ret);
 		return ret;
 	}

 	return 0;
 }

 static const struct of_device_id ipcr_fifo_xprt_match_table[] = {
 	{ .compatible = "qcom,ipcr-fifo-xprt" },
 	{},
 };

 static struct platform_driver ipcr_fifo_xprt_driver = {
 	.probe = ipcr_fifo_xprt_probe,
 	.driver = {
 		.name = MODULE_NAME,
 		.owner = THIS_MODULE,
 		.of_match_table = ipcr_fifo_xprt_match_table,
 	 },
 };

 static int __init ipcr_fifo_xprt_init(void)
 {
 	int rc;

 	rc = platform_driver_register(&ipcr_fifo_xprt_driver);
 	if (rc) {
 		IPC_RTR_ERR("%s: driver register failed %d\n", __func__, rc);
 		return rc;
 	}

 	return 0;
 }

 module_init(ipcr_fifo_xprt_init);
 MODULE_DESCRIPTION("IPC Router FIFO XPRT");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/* Copyright (c) 2018, The Linux Foundation. All rights reserved.
	*/

	#include <linux/delay.h>
	#include <linux/interrupt.h>
	#include <linux/ipc_router_xprt.h>
	#include <linux/io.h>
	#include <linux/of_device.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/types.h>
	#include <linux/skbuff.h>
	#include <linux/sched.h>
	#include <microvisor/microvisor.h>

	#define MODULE_NAME "ipc_router_fifo_xprt"
	#define XPRT_NAME_LEN 32

	#define FIFO_MAGIC_KEY 0x24495043 /* "$IPC" */
	#define FIFO_SIZE 0x4000
	#define FIFO_0_START 0x1000
	#define FIFO_1_START (FIFO_0_START + FIFO_SIZE)
	#define FIFO_MAGIC_IDX 0x0
	#define TAIL_0_IDX 0x1
	#define HEAD_0_IDX 0x2
	#define TAIL_1_IDX 0x3
	#define HEAD_1_IDX 0x4

	struct msm_ipc_pipe {
	__le32 *tail;
	__le32 *head;

	void *fifo;
	size_t length;
	};

	/**
	* ipcr_fifo_xprt - IPC Router's FIFO XPRT structure
	* @xprt: IPC Router XPRT structure to contain XPRT specific info.
	* @tx_pipe: TX FIFO specific info.
	* @rx_pipe: RX FIFO specific info.
	* @fifo_xprt_wq: Workqueue to queue read & other XPRT related works.
	* @in_pkt: Pointer to any partially read packet.
	* @read_work: Read Work to perform read operation from SMD.
	* @sft_close_complete: Variable to indicate completion of SSR handling
	* by IPC Router.
	* @xprt_version: IPC Router header version supported by this XPRT.
	* @driver: Platform drivers register by this XPRT.
	* @xprt_name: Name of the XPRT to be registered with IPC Router.
	*/
	struct ipcr_fifo_xprt {
	struct msm_ipc_router_xprt xprt;
	struct msm_ipc_pipe tx_pipe;
	struct msm_ipc_pipe rx_pipe;
	struct workqueue_struct *xprt_wq;
	struct rr_packet *in_pkt;
	struct delayed_work read_work;
	struct completion sft_close_complete;
	unsigned int xprt_version;
	struct platform_driver driver;
	char xprt_name[XPRT_NAME_LEN];
	void *fifo_base;
	size_t fifo_size;
	int tx_fifo_idx;
	okl4_kcap_t kcap;
	};

	static void xprt_read_data(struct work_struct *work);
	static void ipcr_fifo_raise_virq(struct ipcr_fifo_xprt *xprtp);

	static size_t fifo_rx_avail(struct msm_ipc_pipe *pipe)
	{
	u32 head;
	u32 tail;

	head = le32_to_cpu(*pipe->head);
	tail = le32_to_cpu(*pipe->tail);

	if (head < tail)
	return pipe->length - tail + head;

	return head - tail;
	}

	static void fifo_rx_peak(struct msm_ipc_pipe *pipe,
	void *data, unsigned int offset, size_t count)
	{
	size_t len;
	u32 tail;

	tail = le32_to_cpu(*pipe->tail);
	tail += offset;
	if (tail >= pipe->length)
	tail -= pipe->length;

	len = min_t(size_t, count, pipe->length - tail);
	if (len)
	memcpy_fromio(data, pipe->fifo + tail, len);

	if (len != count)
	memcpy_fromio(data + len, pipe->fifo, (count - len));
	}

	static void fifo_rx_advance(struct msm_ipc_pipe *pipe, size_t count)
	{
	u32 tail;

	tail = le32_to_cpu(*pipe->tail);

	tail += count;
	if (tail > pipe->length)
	tail -= pipe->length;

	*pipe->tail = cpu_to_le32(tail);
	}

	static size_t fifo_tx_avail(struct msm_ipc_pipe *pipe)
	{
	u32 head;
	u32 tail;
	u32 avail;

	head = le32_to_cpu(*pipe->head);
	tail = le32_to_cpu(*pipe->tail);

	if (tail <= head)
	avail = pipe->length - head + tail;
	else
	avail = tail - head;

	return avail;
	}

	static void fifo_tx_write(struct msm_ipc_pipe *pipe,
	const void *data, size_t count)
	{
	size_t len;
	u32 head;

	head = le32_to_cpu(*pipe->head);

	len = min_t(size_t, count, pipe->length - head);
	if (len)
	memcpy_toio(pipe->fifo + head, data, len);

	if (len != count)
	memcpy_toio(pipe->fifo, data + len, count - len);

	head += count;
	if (head >= pipe->length)
	head -= pipe->length;

	/* Ensure ordering of fifo and head update */
	wmb();

	*pipe->head = cpu_to_le32(head);
	}

	/**
	* set_xprt_version() - Set IPC Router header version in the transport
	* @xprt: Reference to the transport structure.
	* @version: The version to be set in transport.
	*/
	static void set_xprt_version(struct msm_ipc_router_xprt *xprt,
	unsigned int version)
	{
	struct ipcr_fifo_xprt *xprtp;

	if (!xprt)
	return;
	xprtp = container_of(xprt, struct ipcr_fifo_xprt, xprt);
	xprtp->xprt_version = version;
	}

	static int get_xprt_version(struct msm_ipc_router_xprt *xprt)
	{
	struct ipcr_fifo_xprt *xprtp;

	if (!xprt)
	return -EINVAL;
	xprtp = container_of(xprt, struct ipcr_fifo_xprt, xprt);
	return (int)xprtp->xprt_version;
	}

	static int get_xprt_option(struct msm_ipc_router_xprt *xprt)
	{
	/* fragmented data is NOT supported */
	return 0;
	}

	static int xprt_close(struct msm_ipc_router_xprt *xprt)
	{
	return 0;
	}

	static void xprt_sft_close_done(struct msm_ipc_router_xprt *xprt)
	{
	struct ipcr_fifo_xprt *xprtp;

	if (!xprt)
	return;

	xprtp = container_of(xprt, struct ipcr_fifo_xprt, xprt);
	complete_all(&xprtp->sft_close_complete);
	}

	static int xprt_write(void *data, uint32_t len,
	struct msm_ipc_router_xprt *xprt)
	{
	struct rr_packet pkt = (struct rr_packet )data;
	struct sk_buff *skb;
	struct ipcr_fifo_xprt *xprtp;

	xprtp = container_of(xprt, struct ipcr_fifo_xprt, xprt);

	if (!pkt)
	return -EINVAL;

	if (!len \|\| pkt->length != len)
	return -EINVAL;

	/* TODO: FIFO write : check if we can write full packet at one shot */
	if (skb_queue_len(pkt->pkt_fragment_q) != 1) {
	pr_err("IPC router core is given fragmented data\n");
	return -EINVAL;
	}
	if (fifo_tx_avail(&xprtp->tx_pipe) < len) {
	pr_err("No Space in FIFO\n");
	return -EAGAIN;
	}

	skb_queue_walk(pkt->pkt_fragment_q, skb) {
	fifo_tx_write(&xprtp->tx_pipe, skb->data, skb->len);
	}

	ipcr_fifo_raise_virq(xprtp);

	return len;
	}

	static void xprt_read_data(struct work_struct *work)
	{
	void *data;
	size_t hdr_len;
	size_t rx_avail;
	size_t pkt_len;
	struct rr_header_v1 hdr;
	struct sk_buff *ipc_rtr_pkt;
	struct ipcr_fifo_xprt *xprtp;
	struct delayed_work *rwork = to_delayed_work(work);

	xprtp = container_of(rwork, struct ipcr_fifo_xprt, read_work);

	hdr_len = sizeof(struct rr_header_v1);
	while (1) {
	rx_avail = fifo_rx_avail(&xprtp->rx_pipe);
	if (!rx_avail)
	break;

	fifo_rx_peak(&xprtp->rx_pipe, &hdr, 0, hdr_len);
	pkt_len = ipc_router_peek_pkt_size((char *)&hdr);

	if (pkt_len < 0) {
	pr_err("%s invalid pkt_len %zu\n", __func__, pkt_len);
	break;
	}
	if (!xprtp->in_pkt) {
	xprtp->in_pkt = create_pkt(NULL);
	if (!xprtp->in_pkt)
	break;
	}
	ipc_rtr_pkt = alloc_skb(pkt_len, GFP_KERNEL);
	if (!ipc_rtr_pkt) {
	release_pkt(xprtp->in_pkt);
	xprtp->in_pkt = NULL;
	break;
	}
	data = skb_put(ipc_rtr_pkt, pkt_len);
	do {
	rx_avail = fifo_rx_avail(&xprtp->rx_pipe);
	if (rx_avail >= pkt_len) {
	fifo_rx_peak(&xprtp->rx_pipe, data, 0, pkt_len);
	fifo_rx_advance(&xprtp->rx_pipe, pkt_len);
	break;
	}
	pr_debug("%s wait for FULL PKT [avail: len][%zu:%zu]\n",
	__func__, rx_avail, pkt_len);
	/* wait for complete packet written into FIFO */
	msleep(20);
	} while (1);

	skb_queue_tail(xprtp->in_pkt->pkt_fragment_q, ipc_rtr_pkt);
	xprtp->in_pkt->length = pkt_len;
	msm_ipc_router_xprt_notify(&xprtp->xprt,
	IPC_ROUTER_XPRT_EVENT_DATA,
	(void *)xprtp->in_pkt);
	release_pkt(xprtp->in_pkt);
	xprtp->in_pkt = NULL;
	}
	}

	static void ipcr_fifo_raise_virq(struct ipcr_fifo_xprt *xprtp)
	{
	okl4_error_t err;
	unsigned long payload = 0xffff;

	err = _okl4_sys_vinterrupt_raise(xprtp->kcap, payload);
	}

	static irqreturn_t ipcr_fifo_virq_handler(int irq, void *dev_id)
	{
	struct ipcr_fifo_xprt *xprtp = dev_id;

	queue_delayed_work(xprtp->xprt_wq, &xprtp->read_work, 0);
	return IRQ_HANDLED;
	}

	/**
	* ipcr_fifo_config_init() - init FIFO xprt configs
	*
	* @return: 0 on success, standard Linux error codes on error.
	*
	* This function is called to initialize the FIFO XPRT pointer with
	* the FIFO XPRT configurations either from device tree or static arrays.
	*/
	static int ipcr_fifo_config_init(struct ipcr_fifo_xprt *xprtp)
	{
	__le32 *descs;

	descs = xprtp->fifo_base;
	descs[FIFO_MAGIC_IDX] = FIFO_MAGIC_KEY;

	if (xprtp->tx_fifo_idx) {
	xprtp->tx_pipe.tail = &descs[TAIL_0_IDX];
	xprtp->tx_pipe.head = &descs[HEAD_0_IDX];
	xprtp->tx_pipe.fifo = xprtp->fifo_base + FIFO_0_START;
	xprtp->tx_pipe.length = FIFO_SIZE;

	xprtp->rx_pipe.tail = &descs[TAIL_1_IDX];
	xprtp->rx_pipe.head = &descs[HEAD_1_IDX];
	xprtp->rx_pipe.fifo = xprtp->fifo_base + FIFO_1_START;
	xprtp->rx_pipe.length = FIFO_SIZE;
	} else {
	xprtp->tx_pipe.tail = &descs[TAIL_1_IDX];
	xprtp->tx_pipe.head = &descs[HEAD_1_IDX];
	xprtp->tx_pipe.fifo = xprtp->fifo_base + FIFO_1_START;
	xprtp->tx_pipe.length = FIFO_SIZE;

	xprtp->rx_pipe.tail = &descs[TAIL_0_IDX];
	xprtp->rx_pipe.head = &descs[HEAD_0_IDX];
	xprtp->rx_pipe.fifo = xprtp->fifo_base + FIFO_0_START;
	xprtp->rx_pipe.length = FIFO_SIZE;
	}

	/* Reset respective index */
	*xprtp->tx_pipe.head = 0;
	*xprtp->rx_pipe.tail = 0;

	xprtp->xprt.link_id = 1;
	xprtp->xprt_version = 1;

	strlcpy(xprtp->xprt_name, "IPCR_FIFO_XPRT", XPRT_NAME_LEN);
	xprtp->xprt.name = xprtp->xprt_name;

	xprtp->xprt.set_version = set_xprt_version;
	xprtp->xprt.get_version = get_xprt_version;
	xprtp->xprt.get_option = get_xprt_option;
	xprtp->xprt.read_avail = NULL;
	xprtp->xprt.read = NULL;
	xprtp->xprt.write_avail = NULL;
	xprtp->xprt.write = xprt_write;
	xprtp->xprt.close = xprt_close;
	xprtp->xprt.sft_close_done = xprt_sft_close_done;
	xprtp->xprt.priv = NULL;

	xprtp->in_pkt = NULL;
	xprtp->xprt_wq = create_singlethread_workqueue(xprtp->xprt_name);
	if (!xprtp->xprt_wq)
	return -EFAULT;

	INIT_DELAYED_WORK(&xprtp->read_work, xprt_read_data);

	msm_ipc_router_xprt_notify(&xprtp->xprt,
	IPC_ROUTER_XPRT_EVENT_OPEN,
	NULL);

	if (fifo_rx_avail(&xprtp->rx_pipe))
	queue_delayed_work(xprtp->xprt_wq, &xprtp->read_work, 0);

	return 0;
	}

	/**
	* ipcr_fifo_xprt_probe() - Probe an FIFO xprt
	*
	* @pdev: Platform device corresponding to FIFO xprt.
	*
	* @return: 0 on success, standard Linux error codes on error.
	*
	* This function is called when the underlying device tree driver registers
	* a platform device, mapped to an FIFO transport.
	*/
	static int ipcr_fifo_xprt_probe(struct platform_device *pdev)
	{
	int irq;
	int ret;
	struct resource *r;
	struct device *parent;
	struct ipcr_fifo_xprt *xprtp;
	struct device_node *ipc_irq_np;
	struct device_node *ipc_shm_np;
	struct platform_device *ipc_shm_dev;

	xprtp = devm_kzalloc(&pdev->dev, sizeof(*xprtp), GFP_KERNEL);
	if (IS_ERR_OR_NULL(xprtp))
	return -ENOMEM;

	parent = &pdev->dev;
	ipc_irq_np = parent->of_node;

	irq = platform_get_irq(pdev, 0);

	if (irq >= 0) {
	ret = devm_request_irq(parent, irq, ipcr_fifo_virq_handler,
	IRQF_TRIGGER_RISING, dev_name(parent),
	xprtp);
	if (ret < 0)
	return -ENODEV;
	}

	/* this kcap is required to raise VIRQ */
	ret = of_property_read_u32(ipc_irq_np, "reg", &xprtp->kcap);
	if (ret < 0)
	return -ENODEV;

	ipc_shm_np = of_parse_phandle(ipc_irq_np, "qcom,ipc-shm", 0);
	if (!ipc_shm_np)
	return -ENODEV;

	ipc_shm_dev = of_find_device_by_node(ipc_shm_np);
	if (!ipc_shm_dev)
	return -ENODEV;

	r = platform_get_resource(ipc_shm_dev, IORESOURCE_MEM, 0);
	if (!r) {
	pr_err("%s failed to get shared FIFO\n", __func__);
	return -ENODEV;
	}

	xprtp->tx_fifo_idx = of_property_read_bool(ipc_shm_np,
	"qcom,tx-is-first");

	xprtp->fifo_size = resource_size(r);
	xprtp->fifo_base = devm_ioremap_nocache(&pdev->dev, r->start,
	resource_size(r));
	if (!xprtp->fifo_base) {
	pr_err("%s ioreamp_nocache() failed\n", __func__);
	return -ENOMEM;
	}

	ret = ipcr_fifo_config_init(xprtp);
	if (ret) {
	IPC_RTR_ERR("%s init failed ret[%d]\n", __func__, ret);
	return ret;
	}

	return 0;
	}

	static const struct of_device_id ipcr_fifo_xprt_match_table[] = {
	{ .compatible = "qcom,ipcr-fifo-xprt" },
	{},
	};

	static struct platform_driver ipcr_fifo_xprt_driver = {
	.probe = ipcr_fifo_xprt_probe,
	.driver = {
	.name = MODULE_NAME,
	.owner = THIS_MODULE,
	.of_match_table = ipcr_fifo_xprt_match_table,
	},
	};

	static int __init ipcr_fifo_xprt_init(void)
	{
	int rc;

	rc = platform_driver_register(&ipcr_fifo_xprt_driver);
	if (rc) {
	IPC_RTR_ERR("%s: driver register failed %d\n", __func__, rc);
	return rc;
	}

	return 0;
	}

	module_init(ipcr_fifo_xprt_init);
	MODULE_DESCRIPTION("IPC Router FIFO XPRT");
	MODULE_LICENSE("GPL v2");