Merge tag 'rpmsg-v4.14' of git://github.com/andersson/remoteproc

Pull rpmsg updates from Bjorn Andersson:
"This extends the Qualcomm GLINK implementation to support the
additional features used for communicating with modem and DSP
coprocessors in modern Qualcomm platforms.

In addition to this there's support for placing virtio RPMSG buffers
in non-System RAM"

* tag 'rpmsg-v4.14' of git://github.com/andersson/remoteproc: (29 commits)
rpmsg: glink: initialize ret to zero to ensure error status check is correct
rpmsg: glink: fix null pointer dereference on a null intent
dt-bindings: soc: qcom: Extend GLINK to cover SMEM
remoteproc: qcom: adsp: Allow defining GLINK edge
rpmsg: glink: Export symbols from common code
rpmsg: glink: Release idr lock before returning on error
rpmsg: glink: Handle remote rx done command
rpmsg: glink: Request for intents when unavailable
rpmsg: glink: Use the intents passed by remote
rpmsg: glink: Receive and store the remote intent buffers
rpmsg: glink: Add announce_create ops and preallocate intents
rpmsg: glink: Add rx done command
rpmsg: glink: Make RX FIFO peak accessor to take an offset
rpmsg: glink: Use the local intents when receiving data
rpmsg: glink: Add support for TX intents
rpmsg: glink: Fix idr_lock from mutex to spinlock
rpmsg: glink: Add support for transport version negotiation
rpmsg: glink: Introduce glink smem based transport
rpmsg: glink: Do a mbox_free_channel in remove
rpmsg: glink: Return -EAGAIN when there is no FIFO space
...

Documentation/devicetree/bindings/remoteproc/qcom,adsp.txt

···
 
 
 = SUBNODES
-The adsp node may have an subnode named "smd-edge" that describes the SMD edge,
-channels and devices related to the ADSP.  See ../soc/qcom/qcom,smd.txt for
-details on how to describe the SMD edge.
+The adsp node may have an subnode named either "smd-edge" or "glink-edge" that
+describes the communication edge, channels and devices related to the ADSP.
+See ../soc/qcom/qcom,smd.txt and ../soc/qcom/qcom,glink.txt for details on how
+to describe these.
 
 
 = EXAMPLE

Documentation/devicetree/bindings/remoteproc/qcom,q6v5.txt

···
 	Value type: <phandle>
 	Definition: reference to the reserved-memory for the region
 
+The Hexagon node may also have an subnode named either "smd-edge" or
+"glink-edge" that describes the communication edge, channels and devices
+related to the Hexagon.  See ../soc/qcom/qcom,smd.txt and
+../soc/qcom/qcom,glink.txt for details on how to describe these.
+
 = EXAMPLE
 The following example describes the resources needed to boot control the
 Hexagon, as it is found on MSM8974 boards.

Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt

···
-Qualcomm RPM GLINK binding
+Qualcomm GLINK edge binding
 
-This binding describes the Qualcomm RPM GLINK, a fifo based mechanism for
-communication with the Resource Power Management system on various Qualcomm
-platforms.
+This binding describes a Qualcomm GLINK edge, a fifo based mechanism for
+communication between subsystem-pairs on various Qualcomm platforms. Two types
+of edges can be described by the binding; the GLINK RPM edge and a SMEM based
+edge.
 
 - compatible:
-	Usage: required
+	Usage: required for glink-rpm
 	Value type: <stringlist>
 	Definition: must be "qcom,glink-rpm"
 
···
 		    signal this processor about communication related events
 
 - qcom,rpm-msg-ram:
-	Usage: required
+	Usage: required for glink-rpm
 	Value type: <prop-encoded-array>
 	Definition: handle to RPM message memory resource
 

drivers/remoteproc/Kconfig

···
 	depends on OF && ARCH_QCOM
 	depends on QCOM_SMEM
 	depends on RPMSG_QCOM_SMD || (COMPILE_TEST && RPMSG_QCOM_SMD=n)
+	depends on RPMSG_QCOM_GLINK_SMEM || RPMSG_QCOM_GLINK_SMEM=n
 	select MFD_SYSCON
 	select QCOM_MDT_LOADER
 	select QCOM_RPROC_COMMON

drivers/remoteproc/qcom_adsp_pil.c

···
 	void *mem_region;
 	size_t mem_size;
 
+	struct qcom_rproc_glink glink_subdev;
 	struct qcom_rproc_subdev smd_subdev;
 	struct qcom_rproc_ssr ssr_subdev;
 };
···
 		goto free_rproc;
 	}
 
+	qcom_add_glink_subdev(rproc, &adsp->glink_subdev);
 	qcom_add_smd_subdev(rproc, &adsp->smd_subdev);
 	qcom_add_ssr_subdev(rproc, &adsp->ssr_subdev, desc->ssr_name);
 
···
 	qcom_smem_state_put(adsp->state);
 	rproc_del(adsp->rproc);
 
+	qcom_remove_glink_subdev(adsp->rproc, &adsp->glink_subdev);
 	qcom_remove_smd_subdev(adsp->rproc, &adsp->smd_subdev);
 	qcom_remove_ssr_subdev(adsp->rproc, &adsp->ssr_subdev);
 	rproc_free(adsp->rproc);

drivers/remoteproc/qcom_common.c

···
 #include <linux/module.h>
 #include <linux/notifier.h>
 #include <linux/remoteproc.h>
+#include <linux/rpmsg/qcom_glink.h>
 #include <linux/rpmsg/qcom_smd.h>
 
 #include "remoteproc_internal.h"
 #include "qcom_common.h"
 
+#define to_glink_subdev(d) container_of(d, struct qcom_rproc_glink, subdev)
 #define to_smd_subdev(d) container_of(d, struct qcom_rproc_subdev, subdev)
 #define to_ssr_subdev(d) container_of(d, struct qcom_rproc_ssr, subdev)
 
···
 	return &table;
 }
 EXPORT_SYMBOL_GPL(qcom_mdt_find_rsc_table);
+
+static int glink_subdev_probe(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_glink *glink = to_glink_subdev(subdev);
+
+	glink->edge = qcom_glink_smem_register(glink->dev, glink->node);
+
+	return IS_ERR(glink->edge) ? PTR_ERR(glink->edge) : 0;
+}
+
+static void glink_subdev_remove(struct rproc_subdev *subdev)
+{
+	struct qcom_rproc_glink *glink = to_glink_subdev(subdev);
+
+	qcom_glink_smem_unregister(glink->edge);
+	glink->edge = NULL;
+}
+
+/**
+ * qcom_add_glink_subdev() - try to add a GLINK subdevice to rproc
+ * @rproc:	rproc handle to parent the subdevice
+ * @glink:	reference to a GLINK subdev context
+ */
+void qcom_add_glink_subdev(struct rproc *rproc, struct qcom_rproc_glink *glink)
+{
+	struct device *dev = &rproc->dev;
+
+	glink->node = of_get_child_by_name(dev->parent->of_node, "glink-edge");
+	if (!glink->node)
+		return;
+
+	glink->dev = dev;
+	rproc_add_subdev(rproc, &glink->subdev, glink_subdev_probe, glink_subdev_remove);
+}
+EXPORT_SYMBOL_GPL(qcom_add_glink_subdev);
+
+/**
+ * qcom_remove_glink_subdev() - remove a GLINK subdevice from rproc
+ * @rproc:	rproc handle
+ * @glink:	reference to a GLINK subdev context
+ */
+void qcom_remove_glink_subdev(struct rproc *rproc, struct qcom_rproc_glink *glink)
+{
+	rproc_remove_subdev(rproc, &glink->subdev);
+	of_node_put(glink->node);
+}
+EXPORT_SYMBOL_GPL(qcom_remove_glink_subdev);
 
 static int smd_subdev_probe(struct rproc_subdev *subdev)
 {

drivers/remoteproc/qcom_common.h

···
 #include <linux/remoteproc.h>
 #include "remoteproc_internal.h"
 
+struct qcom_rproc_glink {
+	struct rproc_subdev subdev;
+
+	struct device *dev;
+	struct device_node *node;
+	struct qcom_glink *edge;
+};
+
 struct qcom_rproc_subdev {
 	struct rproc_subdev subdev;
 
···
 struct resource_table *qcom_mdt_find_rsc_table(struct rproc *rproc,
 					       const struct firmware *fw,
 					       int *tablesz);
+
+void qcom_add_glink_subdev(struct rproc *rproc, struct qcom_rproc_glink *glink);
+void qcom_remove_glink_subdev(struct rproc *rproc, struct qcom_rproc_glink *glink);
 
 void qcom_add_smd_subdev(struct rproc *rproc, struct qcom_rproc_subdev *smd);
 void qcom_remove_smd_subdev(struct rproc *rproc, struct qcom_rproc_subdev *smd);

drivers/rpmsg/Kconfig

···
 	  in /dev. They make it possible for user-space programs to send and
 	  receive rpmsg packets.
 
+config RPMSG_QCOM_GLINK_NATIVE
+	tristate
+	select RPMSG
+
 config RPMSG_QCOM_GLINK_RPM
 	tristate "Qualcomm RPM Glink driver"
-	select RPMSG
+        select RPMSG_QCOM_GLINK_NATIVE
 	depends on HAS_IOMEM
 	depends on MAILBOX
 	help
 	  Say y here to enable support for the GLINK RPM communication driver,
 	  which serves as a channel for communication with the RPM in GLINK
 	  enabled systems.
+
+config RPMSG_QCOM_GLINK_SMEM
+	tristate "Qualcomm SMEM Glink driver"
+	select RPMSG_QCOM_GLINK_NATIVE
+	depends on MAILBOX
+	depends on QCOM_SMEM
+	help
+	  Say y here to enable support for the GLINK SMEM communication driver,
+	  which provides support for using the GLINK communication protocol
+	  over SMEM.
 
 config RPMSG_QCOM_SMD
 	tristate "Qualcomm Shared Memory Driver (SMD)"

drivers/rpmsg/Makefile

···
 obj-$(CONFIG_RPMSG)		+= rpmsg_core.o
 obj-$(CONFIG_RPMSG_CHAR)	+= rpmsg_char.o
 obj-$(CONFIG_RPMSG_QCOM_GLINK_RPM) += qcom_glink_rpm.o
+obj-$(CONFIG_RPMSG_QCOM_GLINK_NATIVE) += qcom_glink_native.o
+obj-$(CONFIG_RPMSG_QCOM_GLINK_SMEM) += qcom_glink_smem.o
 obj-$(CONFIG_RPMSG_QCOM_SMD)	+= qcom_smd.o
 obj-$(CONFIG_RPMSG_VIRTIO)	+= virtio_rpmsg_bus.o

drivers/rpmsg/qcom_glink_native.c

···
+/*
+ * Copyright (c) 2016-2017, Linaro Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/idr.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rpmsg.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/mailbox_client.h>
+
+#include "rpmsg_internal.h"
+#include "qcom_glink_native.h"
+
+#define GLINK_NAME_SIZE		32
+#define GLINK_VERSION_1		1
+
+#define RPM_GLINK_CID_MIN	1
+#define RPM_GLINK_CID_MAX	65536
+
+struct glink_msg {
+	__le16 cmd;
+	__le16 param1;
+	__le32 param2;
+	u8 data[];
+} __packed;
+
+/**
+ * struct glink_defer_cmd - deferred incoming control message
+ * @node:	list node
+ * @msg:	message header
+ * data:	payload of the message
+ *
+ * Copy of a received control message, to be added to @rx_queue and processed
+ * by @rx_work of @qcom_glink.
+ */
+struct glink_defer_cmd {
+	struct list_head node;
+
+	struct glink_msg msg;
+	u8 data[];
+};
+
+/**
+ * struct glink_core_rx_intent - RX intent
+ * RX intent
+ *
+ * data: pointer to the data (may be NULL for zero-copy)
+ * id: remote or local intent ID
+ * size: size of the original intent (do not modify)
+ * reuse: To mark if the intent can be reused after first use
+ * in_use: To mark if intent is already in use for the channel
+ * offset: next write offset (initially 0)
+ */
+struct glink_core_rx_intent {
+	void *data;
+	u32 id;
+	size_t size;
+	bool reuse;
+	bool in_use;
+	u32 offset;
+
+	struct list_head node;
+};
+
+/**
+ * struct qcom_glink - driver context, relates to one remote subsystem
+ * @dev:	reference to the associated struct device
+ * @mbox_client: mailbox client
+ * @mbox_chan:  mailbox channel
+ * @rx_pipe:	pipe object for receive FIFO
+ * @tx_pipe:	pipe object for transmit FIFO
+ * @irq:	IRQ for signaling incoming events
+ * @rx_work:	worker for handling received control messages
+ * @rx_lock:	protects the @rx_queue
+ * @rx_queue:	queue of received control messages to be processed in @rx_work
+ * @tx_lock:	synchronizes operations on the tx fifo
+ * @idr_lock:	synchronizes @lcids and @rcids modifications
+ * @lcids:	idr of all channels with a known local channel id
+ * @rcids:	idr of all channels with a known remote channel id
+ */
+struct qcom_glink {
+	struct device *dev;
+
+	struct mbox_client mbox_client;
+	struct mbox_chan *mbox_chan;
+
+	struct qcom_glink_pipe *rx_pipe;
+	struct qcom_glink_pipe *tx_pipe;
+
+	int irq;
+
+	struct work_struct rx_work;
+	spinlock_t rx_lock;
+	struct list_head rx_queue;
+
+	struct mutex tx_lock;
+
+	spinlock_t idr_lock;
+	struct idr lcids;
+	struct idr rcids;
+	unsigned long features;
+
+	bool intentless;
+};
+
+enum {
+	GLINK_STATE_CLOSED,
+	GLINK_STATE_OPENING,
+	GLINK_STATE_OPEN,
+	GLINK_STATE_CLOSING,
+};
+
+/**
+ * struct glink_channel - internal representation of a channel
+ * @rpdev:	rpdev reference, only used for primary endpoints
+ * @ept:	rpmsg endpoint this channel is associated with
+ * @glink:	qcom_glink context handle
+ * @refcount:	refcount for the channel object
+ * @recv_lock:	guard for @ept.cb
+ * @name:	unique channel name/identifier
+ * @lcid:	channel id, in local space
+ * @rcid:	channel id, in remote space
+ * @intent_lock: lock for protection of @liids, @riids
+ * @liids:	idr of all local intents
+ * @riids:	idr of all remote intents
+ * @intent_work: worker responsible for transmitting rx_done packets
+ * @done_intents: list of intents that needs to be announced rx_done
+ * @buf:	receive buffer, for gathering fragments
+ * @buf_offset:	write offset in @buf
+ * @buf_size:	size of current @buf
+ * @open_ack:	completed once remote has acked the open-request
+ * @open_req:	completed once open-request has been received
+ * @intent_req_lock: Synchronises multiple intent requests
+ * @intent_req_result: Result of intent request
+ * @intent_req_comp: Completion for intent_req signalling
+ */
+struct glink_channel {
+	struct rpmsg_endpoint ept;
+
+	struct rpmsg_device *rpdev;
+	struct qcom_glink *glink;
+
+	struct kref refcount;
+
+	spinlock_t recv_lock;
+
+	char *name;
+	unsigned int lcid;
+	unsigned int rcid;
+
+	spinlock_t intent_lock;
+	struct idr liids;
+	struct idr riids;
+	struct work_struct intent_work;
+	struct list_head done_intents;
+
+	struct glink_core_rx_intent *buf;
+	int buf_offset;
+	int buf_size;
+
+	struct completion open_ack;
+	struct completion open_req;
+
+	struct mutex intent_req_lock;
+	bool intent_req_result;
+	struct completion intent_req_comp;
+};
+
+#define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
+
+static const struct rpmsg_endpoint_ops glink_endpoint_ops;
+
+#define RPM_CMD_VERSION			0
+#define RPM_CMD_VERSION_ACK		1
+#define RPM_CMD_OPEN			2
+#define RPM_CMD_CLOSE			3
+#define RPM_CMD_OPEN_ACK		4
+#define RPM_CMD_INTENT			5
+#define RPM_CMD_RX_DONE			6
+#define RPM_CMD_RX_INTENT_REQ		7
+#define RPM_CMD_RX_INTENT_REQ_ACK	8
+#define RPM_CMD_TX_DATA			9
+#define RPM_CMD_CLOSE_ACK		11
+#define RPM_CMD_TX_DATA_CONT		12
+#define RPM_CMD_READ_NOTIF		13
+#define RPM_CMD_RX_DONE_W_REUSE		14
+
+#define GLINK_FEATURE_INTENTLESS	BIT(1)
+
+static void qcom_glink_rx_done_work(struct work_struct *work);
+
+static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
+						      const char *name)
+{
+	struct glink_channel *channel;
+
+	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
+	if (!channel)
+		return ERR_PTR(-ENOMEM);
+
+	/* Setup glink internal glink_channel data */
+	spin_lock_init(&channel->recv_lock);
+	spin_lock_init(&channel->intent_lock);
+
+	channel->glink = glink;
+	channel->name = kstrdup(name, GFP_KERNEL);
+
+	init_completion(&channel->open_req);
+	init_completion(&channel->open_ack);
+
+	INIT_LIST_HEAD(&channel->done_intents);
+	INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
+
+	idr_init(&channel->liids);
+	idr_init(&channel->riids);
+	kref_init(&channel->refcount);
+
+	return channel;
+}
+
+static void qcom_glink_channel_release(struct kref *ref)
+{
+	struct glink_channel *channel = container_of(ref, struct glink_channel,
+						     refcount);
+	unsigned long flags;
+
+	spin_lock_irqsave(&channel->intent_lock, flags);
+	idr_destroy(&channel->liids);
+	idr_destroy(&channel->riids);
+	spin_unlock_irqrestore(&channel->intent_lock, flags);
+
+	kfree(channel->name);
+	kfree(channel);
+}
+
+static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
+{
+	return glink->rx_pipe->avail(glink->rx_pipe);
+}
+
+static void qcom_glink_rx_peak(struct qcom_glink *glink,
+			       void *data, unsigned int offset, size_t count)
+{
+	glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
+}
+
+static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
+{
+	glink->rx_pipe->advance(glink->rx_pipe, count);
+}
+
+static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
+{
+	return glink->tx_pipe->avail(glink->tx_pipe);
+}
+
+static void qcom_glink_tx_write(struct qcom_glink *glink,
+				const void *hdr, size_t hlen,
+				const void *data, size_t dlen)
+{
+	glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
+}
+
+static int qcom_glink_tx(struct qcom_glink *glink,
+			 const void *hdr, size_t hlen,
+			 const void *data, size_t dlen, bool wait)
+{
+	unsigned int tlen = hlen + dlen;
+	int ret;
+
+	/* Reject packets that are too big */
+	if (tlen >= glink->tx_pipe->length)
+		return -EINVAL;
+
+	ret = mutex_lock_interruptible(&glink->tx_lock);
+	if (ret)
+		return ret;
+
+	while (qcom_glink_tx_avail(glink) < tlen) {
+		if (!wait) {
+			ret = -EAGAIN;
+			goto out;
+		}
+
+		usleep_range(10000, 15000);
+	}
+
+	qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
+
+	mbox_send_message(glink->mbox_chan, NULL);
+	mbox_client_txdone(glink->mbox_chan, 0);
+
+out:
+	mutex_unlock(&glink->tx_lock);
+
+	return ret;
+}
+
+static int qcom_glink_send_version(struct qcom_glink *glink)
+{
+	struct glink_msg msg;
+
+	msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
+	msg.param1 = cpu_to_le16(GLINK_VERSION_1);
+	msg.param2 = cpu_to_le32(glink->features);
+
+	return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
+}
+
+static void qcom_glink_send_version_ack(struct qcom_glink *glink)
+{
+	struct glink_msg msg;
+
+	msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
+	msg.param1 = cpu_to_le16(GLINK_VERSION_1);
+	msg.param2 = cpu_to_le32(glink->features);
+
+	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
+}
+
+static void qcom_glink_send_open_ack(struct qcom_glink *glink,
+				     struct glink_channel *channel)
+{
+	struct glink_msg msg;
+
+	msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
+	msg.param1 = cpu_to_le16(channel->rcid);
+	msg.param2 = cpu_to_le32(0);
+
+	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
+}
+
+static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
+					     unsigned int cid, bool granted)
+{
+	struct glink_channel *channel;
+	unsigned long flags;
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	channel = idr_find(&glink->rcids, cid);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+	if (!channel) {
+		dev_err(glink->dev, "unable to find channel\n");
+		return;
+	}
+
+	channel->intent_req_result = granted;
+	complete(&channel->intent_req_comp);
+}
+
+/**
+ * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
+ * @glink: Ptr to the glink edge
+ * @channel: Ptr to the channel that the open req is sent
+ *
+ * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
+ * Will return with refcount held, regardless of outcome.
+ *
+ * Returns 0 on success, negative errno otherwise.
+ */
+static int qcom_glink_send_open_req(struct qcom_glink *glink,
+				    struct glink_channel *channel)
+{
+	struct {
+		struct glink_msg msg;
+		u8 name[GLINK_NAME_SIZE];
+	} __packed req;
+	int name_len = strlen(channel->name) + 1;
+	int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
+	int ret;
+	unsigned long flags;
+
+	kref_get(&channel->refcount);
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	ret = idr_alloc_cyclic(&glink->lcids, channel,
+			       RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
+			       GFP_ATOMIC);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+	if (ret < 0)
+		return ret;
+
+	channel->lcid = ret;
+
+	req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
+	req.msg.param1 = cpu_to_le16(channel->lcid);
+	req.msg.param2 = cpu_to_le32(name_len);
+	strcpy(req.name, channel->name);
+
+	ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
+	if (ret)
+		goto remove_idr;
+
+	return 0;
+
+remove_idr:
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	idr_remove(&glink->lcids, channel->lcid);
+	channel->lcid = 0;
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+
+	return ret;
+}
+
+static void qcom_glink_send_close_req(struct qcom_glink *glink,
+				      struct glink_channel *channel)
+{
+	struct glink_msg req;
+
+	req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
+	req.param1 = cpu_to_le16(channel->lcid);
+	req.param2 = 0;
+
+	qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
+}
+
+static void qcom_glink_send_close_ack(struct qcom_glink *glink,
+				      unsigned int rcid)
+{
+	struct glink_msg req;
+
+	req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
+	req.param1 = cpu_to_le16(rcid);
+	req.param2 = 0;
+
+	qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
+}
+
+static void qcom_glink_rx_done_work(struct work_struct *work)
+{
+	struct glink_channel *channel = container_of(work, struct glink_channel,
+						     intent_work);
+	struct qcom_glink *glink = channel->glink;
+	struct glink_core_rx_intent *intent, *tmp;
+	struct {
+		u16 id;
+		u16 lcid;
+		u32 liid;
+	} __packed cmd;
+
+	unsigned int cid = channel->lcid;
+	unsigned int iid;
+	bool reuse;
+	unsigned long flags;
+
+	spin_lock_irqsave(&channel->intent_lock, flags);
+	list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
+		list_del(&intent->node);
+		spin_unlock_irqrestore(&channel->intent_lock, flags);
+		iid = intent->id;
+		reuse = intent->reuse;
+
+		cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
+		cmd.lcid = cid;
+		cmd.liid = iid;
+
+		qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
+		if (!reuse) {
+			kfree(intent->data);
+			kfree(intent);
+		}
+		spin_lock_irqsave(&channel->intent_lock, flags);
+	}
+	spin_unlock_irqrestore(&channel->intent_lock, flags);
+}
+
+static void qcom_glink_rx_done(struct qcom_glink *glink,
+			       struct glink_channel *channel,
+			       struct glink_core_rx_intent *intent)
+{
+	/* We don't send RX_DONE to intentless systems */
+	if (glink->intentless) {
+		kfree(intent->data);
+		kfree(intent);
+		return;
+	}
+
+	/* Take it off the tree of receive intents */
+	if (!intent->reuse) {
+		spin_lock(&channel->intent_lock);
+		idr_remove(&channel->liids, intent->id);
+		spin_unlock(&channel->intent_lock);
+	}
+
+	/* Schedule the sending of a rx_done indication */
+	spin_lock(&channel->intent_lock);
+	list_add_tail(&intent->node, &channel->done_intents);
+	spin_unlock(&channel->intent_lock);
+
+	schedule_work(&channel->intent_work);
+}
+
+/**
+ * qcom_glink_receive_version() - receive version/features from remote system
+ *
+ * @glink:	pointer to transport interface
+ * @r_version:	remote version
+ * @r_features:	remote features
+ *
+ * This function is called in response to a remote-initiated version/feature
+ * negotiation sequence.
+ */
+static void qcom_glink_receive_version(struct qcom_glink *glink,
+				       u32 version,
+				       u32 features)
+{
+	switch (version) {
+	case 0:
+		break;
+	case GLINK_VERSION_1:
+		glink->features &= features;
+		/* FALLTHROUGH */
+	default:
+		qcom_glink_send_version_ack(glink);
+		break;
+	}
+}
+
+/**
+ * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
+ *
+ * @glink:	pointer to transport interface
+ * @r_version:	remote version response
+ * @r_features:	remote features response
+ *
+ * This function is called in response to a local-initiated version/feature
+ * negotiation sequence and is the counter-offer from the remote side based
+ * upon the initial version and feature set requested.
+ */
+static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
+					   u32 version,
+					   u32 features)
+{
+	switch (version) {
+	case 0:
+		/* Version negotiation failed */
+		break;
+	case GLINK_VERSION_1:
+		if (features == glink->features)
+			break;
+
+		glink->features &= features;
+		/* FALLTHROUGH */
+	default:
+		qcom_glink_send_version(glink);
+		break;
+	}
+}
+
+/**
+ * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
+				      wire format and transmit
+ * @glink:	The transport to transmit on.
+ * @channel:	The glink channel
+ * @granted:	The request response to encode.
+ *
+ * Return: 0 on success or standard Linux error code.
+ */
+static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
+					  struct glink_channel *channel,
+					  bool granted)
+{
+	struct glink_msg msg;
+
+	msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
+	msg.param1 = cpu_to_le16(channel->lcid);
+	msg.param2 = cpu_to_le32(granted);
+
+	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
+
+	return 0;
+}
+
+/**
+ * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
+ *			   transmit
+ * @glink:	The transport to transmit on.
+ * @channel:	The local channel
+ * @size:	The intent to pass on to remote.
+ *
+ * Return: 0 on success or standard Linux error code.
+ */
+static int qcom_glink_advertise_intent(struct qcom_glink *glink,
+				       struct glink_channel *channel,
+				       struct glink_core_rx_intent *intent)
+{
+	struct command {
+		u16 id;
+		u16 lcid;
+		u32 count;
+		u32 size;
+		u32 liid;
+	} __packed;
+	struct command cmd;
+
+	cmd.id = cpu_to_le16(RPM_CMD_INTENT);
+	cmd.lcid = cpu_to_le16(channel->lcid);
+	cmd.count = cpu_to_le32(1);
+	cmd.size = cpu_to_le32(intent->size);
+	cmd.liid = cpu_to_le32(intent->id);
+
+	qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
+
+	return 0;
+}
+
+static struct glink_core_rx_intent *
+qcom_glink_alloc_intent(struct qcom_glink *glink,
+			struct glink_channel *channel,
+			size_t size,
+			bool reuseable)
+{
+	struct glink_core_rx_intent *intent;
+	int ret;
+	unsigned long flags;
+
+	intent = kzalloc(sizeof(*intent), GFP_KERNEL);
+
+	if (!intent)
+		return NULL;
+
+	intent->data = kzalloc(size, GFP_KERNEL);
+	if (!intent->data)
+		return NULL;
+
+	spin_lock_irqsave(&channel->intent_lock, flags);
+	ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
+	if (ret < 0) {
+		spin_unlock_irqrestore(&channel->intent_lock, flags);
+		return NULL;
+	}
+	spin_unlock_irqrestore(&channel->intent_lock, flags);
+
+	intent->id = ret;
+	intent->size = size;
+	intent->reuse = reuseable;
+
+	return intent;
+}
+
+static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
+				      u32 cid, uint32_t iid,
+				      bool reuse)
+{
+	struct glink_core_rx_intent *intent;
+	struct glink_channel *channel;
+	unsigned long flags;
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	channel = idr_find(&glink->rcids, cid);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+	if (!channel) {
+		dev_err(glink->dev, "invalid channel id received\n");
+		return;
+	}
+
+	spin_lock_irqsave(&channel->intent_lock, flags);
+	intent = idr_find(&channel->riids, iid);
+
+	if (!intent) {
+		spin_unlock_irqrestore(&channel->intent_lock, flags);
+		dev_err(glink->dev, "invalid intent id received\n");
+		return;
+	}
+
+	intent->in_use = false;
+
+	if (!reuse) {
+		idr_remove(&channel->riids, intent->id);
+		kfree(intent);
+	}
+	spin_unlock_irqrestore(&channel->intent_lock, flags);
+}
+
+/**
+ * qcom_glink_handle_intent_req() - Receive a request for rx_intent
+ *					    from remote side
+ * if_ptr:      Pointer to the transport interface
+ * rcid:	Remote channel ID
+ * size:	size of the intent
+ *
+ * The function searches for the local channel to which the request for
+ * rx_intent has arrived and allocates and notifies the remote back
+ */
+static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
+					 u32 cid, size_t size)
+{
+	struct glink_core_rx_intent *intent;
+	struct glink_channel *channel;
+	unsigned long flags;
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	channel = idr_find(&glink->rcids, cid);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+
+	if (!channel) {
+		pr_err("%s channel not found for cid %d\n", __func__, cid);
+		return;
+	}
+
+	intent = qcom_glink_alloc_intent(glink, channel, size, false);
+	if (intent)
+		qcom_glink_advertise_intent(glink, channel, intent);
+
+	qcom_glink_send_intent_req_ack(glink, channel, !!intent);
+}
+
+static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
+{
+	struct glink_defer_cmd *dcmd;
+
+	extra = ALIGN(extra, 8);
+
+	if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
+		dev_dbg(glink->dev, "Insufficient data in rx fifo");
+		return -ENXIO;
+	}
+
+	dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
+	if (!dcmd)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&dcmd->node);
+
+	qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
+
+	spin_lock(&glink->rx_lock);
+	list_add_tail(&dcmd->node, &glink->rx_queue);
+	spin_unlock(&glink->rx_lock);
+
+	schedule_work(&glink->rx_work);
+	qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
+
+	return 0;
+}
+
+static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
+{
+	struct glink_core_rx_intent *intent;
+	struct glink_channel *channel;
+	struct {
+		struct glink_msg msg;
+		__le32 chunk_size;
+		__le32 left_size;
+	} __packed hdr;
+	unsigned int chunk_size;
+	unsigned int left_size;
+	unsigned int rcid;
+	unsigned int liid;
+	int ret = 0;
+	unsigned long flags;
+
+	if (avail < sizeof(hdr)) {
+		dev_dbg(glink->dev, "Not enough data in fifo\n");
+		return -EAGAIN;
+	}
+
+	qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
+	chunk_size = le32_to_cpu(hdr.chunk_size);
+	left_size = le32_to_cpu(hdr.left_size);
+
+	if (avail < sizeof(hdr) + chunk_size) {
+		dev_dbg(glink->dev, "Payload not yet in fifo\n");
+		return -EAGAIN;
+	}
+
+	if (WARN(chunk_size % 4, "Incoming data must be word aligned\n"))
+		return -EINVAL;
+
+	rcid = le16_to_cpu(hdr.msg.param1);
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	channel = idr_find(&glink->rcids, rcid);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+	if (!channel) {
+		dev_dbg(glink->dev, "Data on non-existing channel\n");
+
+		/* Drop the message */
+		goto advance_rx;
+	}
+
+	if (glink->intentless) {
+		/* Might have an ongoing, fragmented, message to append */
+		if (!channel->buf) {
+			intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
+			if (!intent)
+				return -ENOMEM;
+
+			intent->data = kmalloc(chunk_size + left_size,
+					       GFP_ATOMIC);
+			if (!intent->data) {
+				kfree(intent);
+				return -ENOMEM;
+			}
+
+			intent->id = 0xbabababa;
+			intent->size = chunk_size + left_size;
+			intent->offset = 0;
+
+			channel->buf = intent;
+		} else {
+			intent = channel->buf;
+		}
+	} else {
+		liid = le32_to_cpu(hdr.msg.param2);
+
+		spin_lock_irqsave(&channel->intent_lock, flags);
+		intent = idr_find(&channel->liids, liid);
+		spin_unlock_irqrestore(&channel->intent_lock, flags);
+
+		if (!intent) {
+			dev_err(glink->dev,
+				"no intent found for channel %s intent %d",
+				channel->name, liid);
+			goto advance_rx;
+		}
+	}
+
+	if (intent->size - intent->offset < chunk_size) {
+		dev_err(glink->dev, "Insufficient space in intent\n");
+
+		/* The packet header lied, drop payload */
+		goto advance_rx;
+	}
+
+	qcom_glink_rx_peak(glink, intent->data + intent->offset,
+			   sizeof(hdr), chunk_size);
+	intent->offset += chunk_size;
+
+	/* Handle message when no fragments remain to be received */
+	if (!left_size) {
+		spin_lock(&channel->recv_lock);
+		if (channel->ept.cb) {
+			channel->ept.cb(channel->ept.rpdev,
+					intent->data,
+					intent->offset,
+					channel->ept.priv,
+					RPMSG_ADDR_ANY);
+		}
+		spin_unlock(&channel->recv_lock);
+
+		intent->offset = 0;
+		channel->buf = NULL;
+
+		qcom_glink_rx_done(glink, channel, intent);
+	}
+
+advance_rx:
+	qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
+
+	return ret;
+}
+
+static void qcom_glink_handle_intent(struct qcom_glink *glink,
+				     unsigned int cid,
+				     unsigned int count,
+				     size_t avail)
+{
+	struct glink_core_rx_intent *intent;
+	struct glink_channel *channel;
+	struct intent_pair {
+		__le32 size;
+		__le32 iid;
+	};
+
+	struct {
+		struct glink_msg msg;
+		struct intent_pair intents[];
+	} __packed * msg;
+
+	const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
+	int ret;
+	int i;
+	unsigned long flags;
+
+	if (avail < msglen) {
+		dev_dbg(glink->dev, "Not enough data in fifo\n");
+		return;
+	}
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	channel = idr_find(&glink->rcids, cid);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+	if (!channel) {
+		dev_err(glink->dev, "intents for non-existing channel\n");
+		return;
+	}
+
+	msg = kmalloc(msglen, GFP_ATOMIC);
+	if (!msg)
+		return;
+
+	qcom_glink_rx_peak(glink, msg, 0, msglen);
+
+	for (i = 0; i < count; ++i) {
+		intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
+		if (!intent)
+			break;
+
+		intent->id = le32_to_cpu(msg->intents[i].iid);
+		intent->size = le32_to_cpu(msg->intents[i].size);
+
+		spin_lock_irqsave(&channel->intent_lock, flags);
+		ret = idr_alloc(&channel->riids, intent,
+				intent->id, intent->id + 1, GFP_ATOMIC);
+		spin_unlock_irqrestore(&channel->intent_lock, flags);
+
+		if (ret < 0)
+			dev_err(glink->dev, "failed to store remote intent\n");
+	}
+
+	kfree(msg);
+	qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
+}
+
+static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
+{
+	struct glink_channel *channel;
+
+	spin_lock(&glink->idr_lock);
+	channel = idr_find(&glink->lcids, lcid);
+	spin_unlock(&glink->idr_lock);
+	if (!channel) {
+		dev_err(glink->dev, "Invalid open ack packet\n");
+		return -EINVAL;
+	}
+
+	complete(&channel->open_ack);
+
+	return 0;
+}
+
+static irqreturn_t qcom_glink_native_intr(int irq, void *data)
+{
+	struct qcom_glink *glink = data;
+	struct glink_msg msg;
+	unsigned int param1;
+	unsigned int param2;
+	unsigned int avail;
+	unsigned int cmd;
+	int ret = 0;
+
+	for (;;) {
+		avail = qcom_glink_rx_avail(glink);
+		if (avail < sizeof(msg))
+			break;
+
+		qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
+
+		cmd = le16_to_cpu(msg.cmd);
+		param1 = le16_to_cpu(msg.param1);
+		param2 = le32_to_cpu(msg.param2);
+
+		switch (cmd) {
+		case RPM_CMD_VERSION:
+		case RPM_CMD_VERSION_ACK:
+		case RPM_CMD_CLOSE:
+		case RPM_CMD_CLOSE_ACK:
+		case RPM_CMD_RX_INTENT_REQ:
+			ret = qcom_glink_rx_defer(glink, 0);
+			break;
+		case RPM_CMD_OPEN_ACK:
+			ret = qcom_glink_rx_open_ack(glink, param1);
+			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
+			break;
+		case RPM_CMD_OPEN:
+			ret = qcom_glink_rx_defer(glink, param2);
+			break;
+		case RPM_CMD_TX_DATA:
+		case RPM_CMD_TX_DATA_CONT:
+			ret = qcom_glink_rx_data(glink, avail);
+			break;
+		case RPM_CMD_READ_NOTIF:
+			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
+
+			mbox_send_message(glink->mbox_chan, NULL);
+			mbox_client_txdone(glink->mbox_chan, 0);
+			break;
+		case RPM_CMD_INTENT:
+			qcom_glink_handle_intent(glink, param1, param2, avail);
+			break;
+		case RPM_CMD_RX_DONE:
+			qcom_glink_handle_rx_done(glink, param1, param2, false);
+			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
+			break;
+		case RPM_CMD_RX_DONE_W_REUSE:
+			qcom_glink_handle_rx_done(glink, param1, param2, true);
+			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
+			break;
+		case RPM_CMD_RX_INTENT_REQ_ACK:
+			qcom_glink_handle_intent_req_ack(glink, param1, param2);
+			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
+			break;
+		default:
+			dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
+			ret = -EINVAL;
+			break;
+		}
+
+		if (ret)
+			break;
+	}
+
+	return IRQ_HANDLED;
+}
+
+/* Locally initiated rpmsg_create_ept */
+static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
+						     const char *name)
+{
+	struct glink_channel *channel;
+	int ret;
+	unsigned long flags;
+
+	channel = qcom_glink_alloc_channel(glink, name);
+	if (IS_ERR(channel))
+		return ERR_CAST(channel);
+
+	ret = qcom_glink_send_open_req(glink, channel);
+	if (ret)
+		goto release_channel;
+
+	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
+	if (!ret)
+		goto err_timeout;
+
+	ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
+	if (!ret)
+		goto err_timeout;
+
+	qcom_glink_send_open_ack(glink, channel);
+
+	return channel;
+
+err_timeout:
+	/* qcom_glink_send_open_req() did register the channel in lcids*/
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	idr_remove(&glink->lcids, channel->lcid);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+
+release_channel:
+	/* Release qcom_glink_send_open_req() reference */
+	kref_put(&channel->refcount, qcom_glink_channel_release);
+	/* Release qcom_glink_alloc_channel() reference */
+	kref_put(&channel->refcount, qcom_glink_channel_release);
+
+	return ERR_PTR(-ETIMEDOUT);
+}
+
+/* Remote initiated rpmsg_create_ept */
+static int qcom_glink_create_remote(struct qcom_glink *glink,
+				    struct glink_channel *channel)
+{
+	int ret;
+
+	qcom_glink_send_open_ack(glink, channel);
+
+	ret = qcom_glink_send_open_req(glink, channel);
+	if (ret)
+		goto close_link;
+
+	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
+	if (!ret) {
+		ret = -ETIMEDOUT;
+		goto close_link;
+	}
+
+	return 0;
+
+close_link:
+	/*
+	 * Send a close request to "undo" our open-ack. The close-ack will
+	 * release the last reference.
+	 */
+	qcom_glink_send_close_req(glink, channel);
+
+	/* Release qcom_glink_send_open_req() reference */
+	kref_put(&channel->refcount, qcom_glink_channel_release);
+
+	return ret;
+}
+
+static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
+						    rpmsg_rx_cb_t cb,
+						    void *priv,
+						    struct rpmsg_channel_info
+									chinfo)
+{
+	struct glink_channel *parent = to_glink_channel(rpdev->ept);
+	struct glink_channel *channel;
+	struct qcom_glink *glink = parent->glink;
+	struct rpmsg_endpoint *ept;
+	const char *name = chinfo.name;
+	int cid;
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	idr_for_each_entry(&glink->rcids, channel, cid) {
+		if (!strcmp(channel->name, name))
+			break;
+	}
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+
+	if (!channel) {
+		channel = qcom_glink_create_local(glink, name);
+		if (IS_ERR(channel))
+			return NULL;
+	} else {
+		ret = qcom_glink_create_remote(glink, channel);
+		if (ret)
+			return NULL;
+	}
+
+	ept = &channel->ept;
+	ept->rpdev = rpdev;
+	ept->cb = cb;
+	ept->priv = priv;
+	ept->ops = &glink_endpoint_ops;
+
+	return ept;
+}
+
+static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
+{
+	struct glink_channel *channel = to_glink_channel(rpdev->ept);
+	struct glink_core_rx_intent *intent;
+	struct qcom_glink *glink = channel->glink;
+	int num_intents = glink->intentless ? 0 : 5;
+
+	/* Channel is now open, advertise base set of intents */
+	while (num_intents--) {
+		intent = qcom_glink_alloc_intent(glink, channel, SZ_1K, true);
+		if (!intent)
+			break;
+
+		qcom_glink_advertise_intent(glink, channel, intent);
+	}
+
+	return 0;
+}
+
+static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
+{
+	struct glink_channel *channel = to_glink_channel(ept);
+	struct qcom_glink *glink = channel->glink;
+	unsigned long flags;
+
+	spin_lock_irqsave(&channel->recv_lock, flags);
+	channel->ept.cb = NULL;
+	spin_unlock_irqrestore(&channel->recv_lock, flags);
+
+	/* Decouple the potential rpdev from the channel */
+	channel->rpdev = NULL;
+
+	qcom_glink_send_close_req(glink, channel);
+}
+
+static int qcom_glink_request_intent(struct qcom_glink *glink,
+				     struct glink_channel *channel,
+				     size_t size)
+{
+	struct {
+		u16 id;
+		u16 cid;
+		u32 size;
+	} __packed cmd;
+
+	int ret;
+
+	mutex_lock(&channel->intent_req_lock);
+
+	reinit_completion(&channel->intent_req_comp);
+
+	cmd.id = RPM_CMD_RX_INTENT_REQ;
+	cmd.cid = channel->lcid;
+	cmd.size = size;
+
+	ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
+	if (ret)
+		return ret;
+
+	ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
+	if (!ret) {
+		dev_err(glink->dev, "intent request timed out\n");
+		ret = -ETIMEDOUT;
+	} else {
+		ret = channel->intent_req_result ? 0 : -ECANCELED;
+	}
+
+	mutex_unlock(&channel->intent_req_lock);
+	return ret;
+}
+
+static int __qcom_glink_send(struct glink_channel *channel,
+			     void *data, int len, bool wait)
+{
+	struct qcom_glink *glink = channel->glink;
+	struct glink_core_rx_intent *intent = NULL;
+	struct glink_core_rx_intent *tmp;
+	int iid = 0;
+	struct {
+		struct glink_msg msg;
+		__le32 chunk_size;
+		__le32 left_size;
+	} __packed req;
+	int ret;
+	unsigned long flags;
+
+	if (!glink->intentless) {
+		while (!intent) {
+			spin_lock_irqsave(&channel->intent_lock, flags);
+			idr_for_each_entry(&channel->riids, tmp, iid) {
+				if (tmp->size >= len && !tmp->in_use) {
+					tmp->in_use = true;
+					intent = tmp;
+					break;
+				}
+			}
+			spin_unlock_irqrestore(&channel->intent_lock, flags);
+
+			/* We found an available intent */
+			if (intent)
+				break;
+
+			if (!wait)
+				return -EBUSY;
+
+			ret = qcom_glink_request_intent(glink, channel, len);
+			if (ret < 0)
+				return ret;
+		}
+
+		iid = intent->id;
+	}
+
+	req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
+	req.msg.param1 = cpu_to_le16(channel->lcid);
+	req.msg.param2 = cpu_to_le32(iid);
+	req.chunk_size = cpu_to_le32(len);
+	req.left_size = cpu_to_le32(0);
+
+	ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
+
+	/* Mark intent available if we failed */
+	if (ret && intent)
+		intent->in_use = false;
+
+	return ret;
+}
+
+static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
+{
+	struct glink_channel *channel = to_glink_channel(ept);
+
+	return __qcom_glink_send(channel, data, len, true);
+}
+
+static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
+{
+	struct glink_channel *channel = to_glink_channel(ept);
+
+	return __qcom_glink_send(channel, data, len, false);
+}
+
+/*
+ * Finds the device_node for the glink child interested in this channel.
+ */
+static struct device_node *qcom_glink_match_channel(struct device_node *node,
+						    const char *channel)
+{
+	struct device_node *child;
+	const char *name;
+	const char *key;
+	int ret;
+
+	for_each_available_child_of_node(node, child) {
+		key = "qcom,glink-channels";
+		ret = of_property_read_string(child, key, &name);
+		if (ret)
+			continue;
+
+		if (strcmp(name, channel) == 0)
+			return child;
+	}
+
+	return NULL;
+}
+
+static const struct rpmsg_device_ops glink_device_ops = {
+	.create_ept = qcom_glink_create_ept,
+	.announce_create = qcom_glink_announce_create,
+};
+
+static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
+	.destroy_ept = qcom_glink_destroy_ept,
+	.send = qcom_glink_send,
+	.trysend = qcom_glink_trysend,
+};
+
+static void qcom_glink_rpdev_release(struct device *dev)
+{
+	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
+	struct glink_channel *channel = to_glink_channel(rpdev->ept);
+
+	channel->rpdev = NULL;
+	kfree(rpdev);
+}
+
+static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
+			      char *name)
+{
+	struct glink_channel *channel;
+	struct rpmsg_device *rpdev;
+	bool create_device = false;
+	struct device_node *node;
+	int lcid;
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	idr_for_each_entry(&glink->lcids, channel, lcid) {
+		if (!strcmp(channel->name, name))
+			break;
+	}
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+
+	if (!channel) {
+		channel = qcom_glink_alloc_channel(glink, name);
+		if (IS_ERR(channel))
+			return PTR_ERR(channel);
+
+		/* The opening dance was initiated by the remote */
+		create_device = true;
+	}
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
+	if (ret < 0) {
+		dev_err(glink->dev, "Unable to insert channel into rcid list\n");
+		spin_unlock_irqrestore(&glink->idr_lock, flags);
+		goto free_channel;
+	}
+	channel->rcid = ret;
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+
+	complete(&channel->open_req);
+
+	if (create_device) {
+		rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
+		if (!rpdev) {
+			ret = -ENOMEM;
+			goto rcid_remove;
+		}
+
+		rpdev->ept = &channel->ept;
+		strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
+		rpdev->src = RPMSG_ADDR_ANY;
+		rpdev->dst = RPMSG_ADDR_ANY;
+		rpdev->ops = &glink_device_ops;
+
+		node = qcom_glink_match_channel(glink->dev->of_node, name);
+		rpdev->dev.of_node = node;
+		rpdev->dev.parent = glink->dev;
+		rpdev->dev.release = qcom_glink_rpdev_release;
+
+		ret = rpmsg_register_device(rpdev);
+		if (ret)
+			goto free_rpdev;
+
+		channel->rpdev = rpdev;
+	}
+
+	return 0;
+
+free_rpdev:
+	kfree(rpdev);
+rcid_remove:
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	idr_remove(&glink->rcids, channel->rcid);
+	channel->rcid = 0;
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+free_channel:
+	/* Release the reference, iff we took it */
+	if (create_device)
+		kref_put(&channel->refcount, qcom_glink_channel_release);
+
+	return ret;
+}
+
+static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
+{
+	struct rpmsg_channel_info chinfo;
+	struct glink_channel *channel;
+	unsigned long flags;
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	channel = idr_find(&glink->rcids, rcid);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+	if (WARN(!channel, "close request on unknown channel\n"))
+		return;
+
+	/* cancel pending rx_done work */
+	cancel_work_sync(&channel->intent_work);
+
+	if (channel->rpdev) {
+		strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
+		chinfo.src = RPMSG_ADDR_ANY;
+		chinfo.dst = RPMSG_ADDR_ANY;
+
+		rpmsg_unregister_device(glink->dev, &chinfo);
+	}
+
+	qcom_glink_send_close_ack(glink, channel->rcid);
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	idr_remove(&glink->rcids, channel->rcid);
+	channel->rcid = 0;
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+
+	kref_put(&channel->refcount, qcom_glink_channel_release);
+}
+
+static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
+{
+	struct glink_channel *channel;
+	unsigned long flags;
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	channel = idr_find(&glink->lcids, lcid);
+	if (WARN(!channel, "close ack on unknown channel\n")) {
+		spin_unlock_irqrestore(&glink->idr_lock, flags);
+		return;
+	}
+
+	idr_remove(&glink->lcids, channel->lcid);
+	channel->lcid = 0;
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+
+	kref_put(&channel->refcount, qcom_glink_channel_release);
+}
+
+static void qcom_glink_work(struct work_struct *work)
+{
+	struct qcom_glink *glink = container_of(work, struct qcom_glink,
+						rx_work);
+	struct glink_defer_cmd *dcmd;
+	struct glink_msg *msg;
+	unsigned long flags;
+	unsigned int param1;
+	unsigned int param2;
+	unsigned int cmd;
+
+	for (;;) {
+		spin_lock_irqsave(&glink->rx_lock, flags);
+		if (list_empty(&glink->rx_queue)) {
+			spin_unlock_irqrestore(&glink->rx_lock, flags);
+			break;
+		}
+		dcmd = list_first_entry(&glink->rx_queue,
+					struct glink_defer_cmd, node);
+		list_del(&dcmd->node);
+		spin_unlock_irqrestore(&glink->rx_lock, flags);
+
+		msg = &dcmd->msg;
+		cmd = le16_to_cpu(msg->cmd);
+		param1 = le16_to_cpu(msg->param1);
+		param2 = le32_to_cpu(msg->param2);
+
+		switch (cmd) {
+		case RPM_CMD_VERSION:
+			qcom_glink_receive_version(glink, param1, param2);
+			break;
+		case RPM_CMD_VERSION_ACK:
+			qcom_glink_receive_version_ack(glink, param1, param2);
+			break;
+		case RPM_CMD_OPEN:
+			qcom_glink_rx_open(glink, param1, msg->data);
+			break;
+		case RPM_CMD_CLOSE:
+			qcom_glink_rx_close(glink, param1);
+			break;
+		case RPM_CMD_CLOSE_ACK:
+			qcom_glink_rx_close_ack(glink, param1);
+			break;
+		case RPM_CMD_RX_INTENT_REQ:
+			qcom_glink_handle_intent_req(glink, param1, param2);
+			break;
+		default:
+			WARN(1, "Unknown defer object %d\n", cmd);
+			break;
+		}
+
+		kfree(dcmd);
+	}
+}
+
+struct qcom_glink *qcom_glink_native_probe(struct device *dev,
+					   unsigned long features,
+					   struct qcom_glink_pipe *rx,
+					   struct qcom_glink_pipe *tx,
+					   bool intentless)
+{
+	int irq;
+	int ret;
+	struct qcom_glink *glink;
+
+	glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
+	if (!glink)
+		return ERR_PTR(-ENOMEM);
+
+	glink->dev = dev;
+	glink->tx_pipe = tx;
+	glink->rx_pipe = rx;
+
+	glink->features = features;
+	glink->intentless = intentless;
+
+	mutex_init(&glink->tx_lock);
+	spin_lock_init(&glink->rx_lock);
+	INIT_LIST_HEAD(&glink->rx_queue);
+	INIT_WORK(&glink->rx_work, qcom_glink_work);
+
+	spin_lock_init(&glink->idr_lock);
+	idr_init(&glink->lcids);
+	idr_init(&glink->rcids);
+
+	glink->mbox_client.dev = dev;
+	glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
+	if (IS_ERR(glink->mbox_chan)) {
+		if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
+			dev_err(dev, "failed to acquire IPC channel\n");
+		return ERR_CAST(glink->mbox_chan);
+	}
+
+	irq = of_irq_get(dev->of_node, 0);
+	ret = devm_request_irq(dev, irq,
+			       qcom_glink_native_intr,
+			       IRQF_NO_SUSPEND | IRQF_SHARED,
+			       "glink-native", glink);
+	if (ret) {
+		dev_err(dev, "failed to request IRQ\n");
+		return ERR_PTR(ret);
+	}
+
+	glink->irq = irq;
+
+	ret = qcom_glink_send_version(glink);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return glink;
+}
+EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
+
+static int qcom_glink_remove_device(struct device *dev, void *data)
+{
+	device_unregister(dev);
+
+	return 0;
+}
+
+void qcom_glink_native_remove(struct qcom_glink *glink)
+{
+	struct glink_channel *channel;
+	int cid;
+	int ret;
+	unsigned long flags;
+
+	disable_irq(glink->irq);
+	cancel_work_sync(&glink->rx_work);
+
+	ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
+	if (ret)
+		dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
+
+	spin_lock_irqsave(&glink->idr_lock, flags);
+	/* Release any defunct local channels, waiting for close-ack */
+	idr_for_each_entry(&glink->lcids, channel, cid)
+		kref_put(&channel->refcount, qcom_glink_channel_release);
+
+	idr_destroy(&glink->lcids);
+	idr_destroy(&glink->rcids);
+	spin_unlock_irqrestore(&glink->idr_lock, flags);
+	mbox_free_channel(glink->mbox_chan);
+}
+EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
+
+void qcom_glink_native_unregister(struct qcom_glink *glink)
+{
+	device_unregister(glink->dev);
+}
+EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);

drivers/rpmsg/qcom_glink_native.h

···
+/*
+ * Copyright (c) 2016-2017, Linaro Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __QCOM_GLINK_NATIVE_H__
+#define __QCOM_GLINK_NATIVE_H__
+
+#define GLINK_FEATURE_INTENT_REUSE	BIT(0)
+#define GLINK_FEATURE_MIGRATION		BIT(1)
+#define GLINK_FEATURE_TRACER_PKT	BIT(2)
+
+struct qcom_glink_pipe {
+	size_t length;
+
+	size_t (*avail)(struct qcom_glink_pipe *glink_pipe);
+
+	void (*peak)(struct qcom_glink_pipe *glink_pipe, void *data,
+		     unsigned int offset, size_t count);
+	void (*advance)(struct qcom_glink_pipe *glink_pipe, size_t count);
+
+	void (*write)(struct qcom_glink_pipe *glink_pipe,
+		      const void *hdr, size_t hlen,
+		      const void *data, size_t dlen);
+};
+
+struct qcom_glink;
+
+struct qcom_glink *qcom_glink_native_probe(struct device *dev,
+					   unsigned long features,
+					   struct qcom_glink_pipe *rx,
+					   struct qcom_glink_pipe *tx,
+					   bool intentless);
+void qcom_glink_native_remove(struct qcom_glink *glink);
+
+void qcom_glink_native_unregister(struct qcom_glink *glink);
+#endif

drivers/rpmsg/qcom_glink_rpm.c

···
 #include <linux/mailbox_client.h>
 
 #include "rpmsg_internal.h"
+#include "qcom_glink_native.h"
 
 #define RPM_TOC_SIZE		256
 #define RPM_TOC_MAGIC		0x67727430 /* grt0 */
···
 #define RPM_TX_FIFO_ID		0x61703272 /* ap2r */
 #define RPM_RX_FIFO_ID		0x72326170 /* r2ap */
 
-#define GLINK_NAME_SIZE		32
-
-#define RPM_GLINK_CID_MIN	1
-#define RPM_GLINK_CID_MAX	65536
+#define to_rpm_pipe(p) container_of(p, struct glink_rpm_pipe, native)
 
 struct rpm_toc_entry {
 	__le32 id;
···
 	struct rpm_toc_entry entries[];
 } __packed;
 
-struct glink_msg {
-	__le16 cmd;
-	__le16 param1;
-	__le32 param2;
-	u8 data[];
-} __packed;
-
 struct glink_rpm_pipe {
+	struct qcom_glink_pipe native;
+
 	void __iomem *tail;
 	void __iomem *head;
 
 	void __iomem *fifo;
-
-	size_t length;
 };
 
-/**
- * struct glink_defer_cmd - deferred incoming control message
- * @node:	list node
- * @msg:	message header
- * data:	payload of the message
- *
- * Copy of a received control message, to be added to @rx_queue and processed
- * by @rx_work of @glink_rpm.
- */
-struct glink_defer_cmd {
-	struct list_head node;
-
-	struct glink_msg msg;
-	u8 data[];
-};
-
-/**
- * struct glink_rpm - driver context, relates to one remote subsystem
- * @dev:	reference to the associated struct device
- * @doorbell:	"rpm_hlos" ipc doorbell
- * @rx_pipe:	pipe object for receive FIFO
- * @tx_pipe:	pipe object for transmit FIFO
- * @irq:	IRQ for signaling incoming events
- * @rx_work:	worker for handling received control messages
- * @rx_lock:	protects the @rx_queue
- * @rx_queue:	queue of received control messages to be processed in @rx_work
- * @tx_lock:	synchronizes operations on the tx fifo
- * @idr_lock:	synchronizes @lcids and @rcids modifications
- * @lcids:	idr of all channels with a known local channel id
- * @rcids:	idr of all channels with a known remote channel id
- */
-struct glink_rpm {
-	struct device *dev;
-
-	struct mbox_client mbox_client;
-	struct mbox_chan *mbox_chan;
-
-	struct glink_rpm_pipe rx_pipe;
-	struct glink_rpm_pipe tx_pipe;
-
-	int irq;
-
-	struct work_struct rx_work;
-	spinlock_t rx_lock;
-	struct list_head rx_queue;
-
-	struct mutex tx_lock;
-
-	struct mutex idr_lock;
-	struct idr lcids;
-	struct idr rcids;
-};
-
-enum {
-	GLINK_STATE_CLOSED,
-	GLINK_STATE_OPENING,
-	GLINK_STATE_OPEN,
-	GLINK_STATE_CLOSING,
-};
-
-/**
- * struct glink_channel - internal representation of a channel
- * @rpdev:	rpdev reference, only used for primary endpoints
- * @ept:	rpmsg endpoint this channel is associated with
- * @glink:	glink_rpm context handle
- * @refcount:	refcount for the channel object
- * @recv_lock:	guard for @ept.cb
- * @name:	unique channel name/identifier
- * @lcid:	channel id, in local space
- * @rcid:	channel id, in remote space
- * @buf:	receive buffer, for gathering fragments
- * @buf_offset:	write offset in @buf
- * @buf_size:	size of current @buf
- * @open_ack:	completed once remote has acked the open-request
- * @open_req:	completed once open-request has been received
- */
-struct glink_channel {
-	struct rpmsg_endpoint ept;
-
-	struct rpmsg_device *rpdev;
-	struct glink_rpm *glink;
-
-	struct kref refcount;
-
-	spinlock_t recv_lock;
-
-	char *name;
-	unsigned int lcid;
-	unsigned int rcid;
-
-	void *buf;
-	int buf_offset;
-	int buf_size;
-
-	struct completion open_ack;
-	struct completion open_req;
-};
-
-#define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
-
-static const struct rpmsg_endpoint_ops glink_endpoint_ops;
-
-#define RPM_CMD_VERSION			0
-#define RPM_CMD_VERSION_ACK		1
-#define RPM_CMD_OPEN			2
-#define RPM_CMD_CLOSE			3
-#define RPM_CMD_OPEN_ACK		4
-#define RPM_CMD_TX_DATA			9
-#define RPM_CMD_CLOSE_ACK		11
-#define RPM_CMD_TX_DATA_CONT		12
-#define RPM_CMD_READ_NOTIF		13
-
-#define GLINK_FEATURE_INTENTLESS	BIT(1)
-
-static struct glink_channel *glink_rpm_alloc_channel(struct glink_rpm *glink,
-						     const char *name)
+static size_t glink_rpm_rx_avail(struct qcom_glink_pipe *glink_pipe)
 {
-	struct glink_channel *channel;
-
-	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
-	if (!channel)
-		return ERR_PTR(-ENOMEM);
-
-	/* Setup glink internal glink_channel data */
-	spin_lock_init(&channel->recv_lock);
-	channel->glink = glink;
-	channel->name = kstrdup(name, GFP_KERNEL);
-
-	init_completion(&channel->open_req);
-	init_completion(&channel->open_ack);
-
-	kref_init(&channel->refcount);
-
-	return channel;
-}
-
-static void glink_rpm_channel_release(struct kref *ref)
-{
-	struct glink_channel *channel = container_of(ref, struct glink_channel,
-						     refcount);
-
-	kfree(channel->name);
-	kfree(channel);
-}
-
-static size_t glink_rpm_rx_avail(struct glink_rpm *glink)
-{
-	struct glink_rpm_pipe *pipe = &glink->rx_pipe;
+	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int head;
 	unsigned int tail;
 
···
 	tail = readl(pipe->tail);
 
 	if (head < tail)
-		return pipe->length - tail + head;
+		return pipe->native.length - tail + head;
 	else
 		return head - tail;
 }
 
-static void glink_rpm_rx_peak(struct glink_rpm *glink,
-			      void *data, size_t count)
+static void glink_rpm_rx_peak(struct qcom_glink_pipe *glink_pipe,
+			      void *data, unsigned int offset, size_t count)
 {
-	struct glink_rpm_pipe *pipe = &glink->rx_pipe;
+	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int tail;
 	size_t len;
 
 	tail = readl(pipe->tail);
+	tail += offset;
+	if (tail >= pipe->native.length)
+		tail -= pipe->native.length;
 
-	len = min_t(size_t, count, pipe->length - tail);
+	len = min_t(size_t, count, pipe->native.length - tail);
 	if (len) {
 		__ioread32_copy(data, pipe->fifo + tail,
 				len / sizeof(u32));
···
 	}
 }
 
-static void glink_rpm_rx_advance(struct glink_rpm *glink,
+static void glink_rpm_rx_advance(struct qcom_glink_pipe *glink_pipe,
 				 size_t count)
 {
-	struct glink_rpm_pipe *pipe = &glink->rx_pipe;
+	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int tail;
 
 	tail = readl(pipe->tail);
 
 	tail += count;
-	if (tail >= pipe->length)
-		tail -= pipe->length;
+	if (tail >= pipe->native.length)
+		tail -= pipe->native.length;
 
 	writel(tail, pipe->tail);
 }
 
-static size_t glink_rpm_tx_avail(struct glink_rpm *glink)
+static size_t glink_rpm_tx_avail(struct qcom_glink_pipe *glink_pipe)
 {
-	struct glink_rpm_pipe *pipe = &glink->tx_pipe;
+	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 	unsigned int head;
 	unsigned int tail;
 
···
 	tail = readl(pipe->tail);
 
 	if (tail <= head)
-		return pipe->length - head + tail;
+		return pipe->native.length - head + tail;
 	else
 		return tail - head;
 }
 
-static unsigned int glink_rpm_tx_write(struct glink_rpm *glink,
-				       unsigned int head,
-				       const void *data, size_t count)
+static unsigned int glink_rpm_tx_write_one(struct glink_rpm_pipe *pipe,
+					   unsigned int head,
+					   const void *data, size_t count)
 {
-	struct glink_rpm_pipe *pipe = &glink->tx_pipe;
 	size_t len;
 
-	len = min_t(size_t, count, pipe->length - head);
+	len = min_t(size_t, count, pipe->native.length - head);
 	if (len) {
 		__iowrite32_copy(pipe->fifo + head, data,
 				 len / sizeof(u32));
···
 	}
 
 	head += count;
-	if (head >= pipe->length)
-		head -= pipe->length;
+	if (head >= pipe->native.length)
+		head -= pipe->native.length;
 
 	return head;
 }
 
-static int glink_rpm_tx(struct glink_rpm *glink,
-			const void *hdr, size_t hlen,
-			const void *data, size_t dlen, bool wait)
+static void glink_rpm_tx_write(struct qcom_glink_pipe *glink_pipe,
+			       const void *hdr, size_t hlen,
+			       const void *data, size_t dlen)
 {
-	struct glink_rpm_pipe *pipe = &glink->tx_pipe;
+	struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
+	size_t tlen = hlen + dlen;
+	size_t aligned_dlen;
 	unsigned int head;
-	unsigned int tlen = hlen + dlen;
-	int ret;
+	char padding[8] = {0};
+	size_t pad;
 
-	/* Reject packets that are too big */
-	if (tlen >= glink->tx_pipe.length)
-		return -EINVAL;
+	/* Header length comes from glink native and is always 4 byte aligned */
+	if (WARN(hlen % 4, "Glink Header length must be 4 bytes aligned\n"))
+		return;
 
-	if (WARN(tlen % 8, "Unaligned TX request"))
-		return -EINVAL;
-
-	ret = mutex_lock_interruptible(&glink->tx_lock);
-	if (ret)
-		return ret;
-
-	while (glink_rpm_tx_avail(glink) < tlen) {
-		if (!wait) {
-			ret = -ENOMEM;
-			goto out;
-		}
-
-		msleep(10);
-	}
+	/*
+	 * Move the unaligned tail of the message to the padding chunk, to
+	 * ensure word aligned accesses
+	 */
+	aligned_dlen = ALIGN_DOWN(dlen, 4);
+	if (aligned_dlen != dlen)
+		memcpy(padding, data + aligned_dlen, dlen - aligned_dlen);
 
 	head = readl(pipe->head);
-	head = glink_rpm_tx_write(glink, head, hdr, hlen);
-	head = glink_rpm_tx_write(glink, head, data, dlen);
+	head = glink_rpm_tx_write_one(pipe, head, hdr, hlen);
+	head = glink_rpm_tx_write_one(pipe, head, data, aligned_dlen);
+
+	pad = ALIGN(tlen, 8) - ALIGN_DOWN(tlen, 4);
+	if (pad)
+		head = glink_rpm_tx_write_one(pipe, head, padding, pad);
 	writel(head, pipe->head);
-
-	mbox_send_message(glink->mbox_chan, NULL);
-	mbox_client_txdone(glink->mbox_chan, 0);
-
-out:
-	mutex_unlock(&glink->tx_lock);
-
-	return ret;
-}
-
-static int glink_rpm_send_version(struct glink_rpm *glink)
-{
-	struct glink_msg msg;
-
-	msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
-	msg.param1 = cpu_to_le16(1);
-	msg.param2 = cpu_to_le32(GLINK_FEATURE_INTENTLESS);
-
-	return glink_rpm_tx(glink, &msg, sizeof(msg), NULL, 0, true);
-}
-
-static void glink_rpm_send_version_ack(struct glink_rpm *glink)
-{
-	struct glink_msg msg;
-
-	msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
-	msg.param1 = cpu_to_le16(1);
-	msg.param2 = cpu_to_le32(0);
-
-	glink_rpm_tx(glink, &msg, sizeof(msg), NULL, 0, true);
-}
-
-static void glink_rpm_send_open_ack(struct glink_rpm *glink,
-					 struct glink_channel *channel)
-{
-	struct glink_msg msg;
-
-	msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
-	msg.param1 = cpu_to_le16(channel->rcid);
-	msg.param2 = cpu_to_le32(0);
-
-	glink_rpm_tx(glink, &msg, sizeof(msg), NULL, 0, true);
-}
-
-/**
- * glink_rpm_send_open_req() - send a RPM_CMD_OPEN request to the remote
- * @glink:
- * @channel:
- *
- * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
- * Will return with refcount held, regardless of outcome.
- *
- * Returns 0 on success, negative errno otherwise.
- */
-static int glink_rpm_send_open_req(struct glink_rpm *glink,
-					 struct glink_channel *channel)
-{
-	struct {
-		struct glink_msg msg;
-		u8 name[GLINK_NAME_SIZE];
-	} __packed req;
-	int name_len = strlen(channel->name) + 1;
-	int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
-	int ret;
-
-	kref_get(&channel->refcount);
-
-	mutex_lock(&glink->idr_lock);
-	ret = idr_alloc_cyclic(&glink->lcids, channel,
-			       RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX, GFP_KERNEL);
-	mutex_unlock(&glink->idr_lock);
-	if (ret < 0)
-		return ret;
-
-	channel->lcid = ret;
-
-	req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
-	req.msg.param1 = cpu_to_le16(channel->lcid);
-	req.msg.param2 = cpu_to_le32(name_len);
-	strcpy(req.name, channel->name);
-
-	ret = glink_rpm_tx(glink, &req, req_len, NULL, 0, true);
-	if (ret)
-		goto remove_idr;
-
-	return 0;
-
-remove_idr:
-	mutex_lock(&glink->idr_lock);
-	idr_remove(&glink->lcids, channel->lcid);
-	channel->lcid = 0;
-	mutex_unlock(&glink->idr_lock);
-
-	return ret;
-}
-
-static void glink_rpm_send_close_req(struct glink_rpm *glink,
-					  struct glink_channel *channel)
-{
-	struct glink_msg req;
-
-	req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
-	req.param1 = cpu_to_le16(channel->lcid);
-	req.param2 = 0;
-
-	glink_rpm_tx(glink, &req, sizeof(req), NULL, 0, true);
-}
-
-static void glink_rpm_send_close_ack(struct glink_rpm *glink, unsigned int rcid)
-{
-	struct glink_msg req;
-
-	req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
-	req.param1 = cpu_to_le16(rcid);
-	req.param2 = 0;
-
-	glink_rpm_tx(glink, &req, sizeof(req), NULL, 0, true);
-}
-
-static int glink_rpm_rx_defer(struct glink_rpm *glink, size_t extra)
-{
-	struct glink_defer_cmd *dcmd;
-
-	extra = ALIGN(extra, 8);
-
-	if (glink_rpm_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
-		dev_dbg(glink->dev, "Insufficient data in rx fifo");
-		return -ENXIO;
-	}
-
-	dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
-	if (!dcmd)
-		return -ENOMEM;
-
-	INIT_LIST_HEAD(&dcmd->node);
-
-	glink_rpm_rx_peak(glink, &dcmd->msg, sizeof(dcmd->msg) + extra);
-
-	spin_lock(&glink->rx_lock);
-	list_add_tail(&dcmd->node, &glink->rx_queue);
-	spin_unlock(&glink->rx_lock);
-
-	schedule_work(&glink->rx_work);
-	glink_rpm_rx_advance(glink, sizeof(dcmd->msg) + extra);
-
-	return 0;
-}
-
-static int glink_rpm_rx_data(struct glink_rpm *glink, size_t avail)
-{
-	struct glink_channel *channel;
-	struct {
-		struct glink_msg msg;
-		__le32 chunk_size;
-		__le32 left_size;
-	} __packed hdr;
-	unsigned int chunk_size;
-	unsigned int left_size;
-	unsigned int rcid;
-
-	if (avail < sizeof(hdr)) {
-		dev_dbg(glink->dev, "Not enough data in fifo\n");
-		return -EAGAIN;
-	}
-
-	glink_rpm_rx_peak(glink, &hdr, sizeof(hdr));
-	chunk_size = le32_to_cpu(hdr.chunk_size);
-	left_size = le32_to_cpu(hdr.left_size);
-
-	if (avail < sizeof(hdr) + chunk_size) {
-		dev_dbg(glink->dev, "Payload not yet in fifo\n");
-		return -EAGAIN;
-	}
-
-	if (WARN(chunk_size % 4, "Incoming data must be word aligned\n"))
-		return -EINVAL;
-
-	rcid = le16_to_cpu(hdr.msg.param1);
-	channel = idr_find(&glink->rcids, rcid);
-	if (!channel) {
-		dev_dbg(glink->dev, "Data on non-existing channel\n");
-
-		/* Drop the message */
-		glink_rpm_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
-		return 0;
-	}
-
-	/* Might have an ongoing, fragmented, message to append */
-	if (!channel->buf) {
-		channel->buf = kmalloc(chunk_size + left_size, GFP_ATOMIC);
-		if (!channel->buf)
-			return -ENOMEM;
-
-		channel->buf_size = chunk_size + left_size;
-		channel->buf_offset = 0;
-	}
-
-	glink_rpm_rx_advance(glink, sizeof(hdr));
-
-	if (channel->buf_size - channel->buf_offset < chunk_size) {
-		dev_err(glink->dev, "Insufficient space in input buffer\n");
-
-		/* The packet header lied, drop payload */
-		glink_rpm_rx_advance(glink, chunk_size);
-		return -ENOMEM;
-	}
-
-	glink_rpm_rx_peak(glink, channel->buf + channel->buf_offset, chunk_size);
-	channel->buf_offset += chunk_size;
-
-	/* Handle message when no fragments remain to be received */
-	if (!left_size) {
-		spin_lock(&channel->recv_lock);
-		if (channel->ept.cb) {
-			channel->ept.cb(channel->ept.rpdev,
-					channel->buf,
-					channel->buf_offset,
-					channel->ept.priv,
-					RPMSG_ADDR_ANY);
-		}
-		spin_unlock(&channel->recv_lock);
-
-		kfree(channel->buf);
-		channel->buf = NULL;
-		channel->buf_size = 0;
-	}
-
-	/* Each message starts at 8 byte aligned address */
-	glink_rpm_rx_advance(glink, ALIGN(chunk_size, 8));
-
-	return 0;
-}
-
-static int glink_rpm_rx_open_ack(struct glink_rpm *glink, unsigned int lcid)
-{
-	struct glink_channel *channel;
-
-	channel = idr_find(&glink->lcids, lcid);
-	if (!channel) {
-		dev_err(glink->dev, "Invalid open ack packet\n");
-		return -EINVAL;
-	}
-
-	complete(&channel->open_ack);
-
-	return 0;
-}
-
-static irqreturn_t glink_rpm_intr(int irq, void *data)
-{
-	struct glink_rpm *glink = data;
-	struct glink_msg msg;
-	unsigned int param1;
-	unsigned int param2;
-	unsigned int avail;
-	unsigned int cmd;
-	int ret;
-
-	for (;;) {
-		avail = glink_rpm_rx_avail(glink);
-		if (avail < sizeof(msg))
-			break;
-
-		glink_rpm_rx_peak(glink, &msg, sizeof(msg));
-
-		cmd = le16_to_cpu(msg.cmd);
-		param1 = le16_to_cpu(msg.param1);
-		param2 = le32_to_cpu(msg.param2);
-
-		switch (cmd) {
-		case RPM_CMD_VERSION:
-		case RPM_CMD_VERSION_ACK:
-		case RPM_CMD_CLOSE:
-		case RPM_CMD_CLOSE_ACK:
-			ret = glink_rpm_rx_defer(glink, 0);
-			break;
-		case RPM_CMD_OPEN_ACK:
-			ret = glink_rpm_rx_open_ack(glink, param1);
-			glink_rpm_rx_advance(glink, ALIGN(sizeof(msg), 8));
-			break;
-		case RPM_CMD_OPEN:
-			ret = glink_rpm_rx_defer(glink, param2);
-			break;
-		case RPM_CMD_TX_DATA:
-		case RPM_CMD_TX_DATA_CONT:
-			ret = glink_rpm_rx_data(glink, avail);
-			break;
-		case RPM_CMD_READ_NOTIF:
-			glink_rpm_rx_advance(glink, ALIGN(sizeof(msg), 8));
-
-			mbox_send_message(glink->mbox_chan, NULL);
-			mbox_client_txdone(glink->mbox_chan, 0);
-
-			ret = 0;
-			break;
-		default:
-			dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
-			ret = -EINVAL;
-			break;
-		}
-
-		if (ret)
-			break;
-	}
-
-	return IRQ_HANDLED;
-}
-
-/* Locally initiated rpmsg_create_ept */
-static struct glink_channel *glink_rpm_create_local(struct glink_rpm *glink,
-						    const char *name)
-{
-	struct glink_channel *channel;
-	int ret;
-
-	channel = glink_rpm_alloc_channel(glink, name);
-	if (IS_ERR(channel))
-		return ERR_CAST(channel);
-
-	ret = glink_rpm_send_open_req(glink, channel);
-	if (ret)
-		goto release_channel;
-
-	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
-	if (!ret)
-		goto err_timeout;
-
-	ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
-	if (!ret)
-		goto err_timeout;
-
-	glink_rpm_send_open_ack(glink, channel);
-
-	return channel;
-
-err_timeout:
-	/* glink_rpm_send_open_req() did register the channel in lcids*/
-	mutex_lock(&glink->idr_lock);
-	idr_remove(&glink->lcids, channel->lcid);
-	mutex_unlock(&glink->idr_lock);
-
-release_channel:
-	/* Release glink_rpm_send_open_req() reference */
-	kref_put(&channel->refcount, glink_rpm_channel_release);
-	/* Release glink_rpm_alloc_channel() reference */
-	kref_put(&channel->refcount, glink_rpm_channel_release);
-
-	return ERR_PTR(-ETIMEDOUT);
-}
-
-/* Remote initiated rpmsg_create_ept */
-static int glink_rpm_create_remote(struct glink_rpm *glink,
-				   struct glink_channel *channel)
-{
-	int ret;
-
-	glink_rpm_send_open_ack(glink, channel);
-
-	ret = glink_rpm_send_open_req(glink, channel);
-	if (ret)
-		goto close_link;
-
-	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
-	if (!ret) {
-		ret = -ETIMEDOUT;
-		goto close_link;
-	}
-
-	return 0;
-
-close_link:
-	/*
-	 * Send a close request to "undo" our open-ack. The close-ack will
-	 * release the last reference.
-	 */
-	glink_rpm_send_close_req(glink, channel);
-
-	/* Release glink_rpm_send_open_req() reference */
-	kref_put(&channel->refcount, glink_rpm_channel_release);
-
-	return ret;
-}
-
-static struct rpmsg_endpoint *glink_rpm_create_ept(struct rpmsg_device *rpdev,
-						  rpmsg_rx_cb_t cb, void *priv,
-						  struct rpmsg_channel_info chinfo)
-{
-	struct glink_channel *parent = to_glink_channel(rpdev->ept);
-	struct glink_channel *channel;
-	struct glink_rpm *glink = parent->glink;
-	struct rpmsg_endpoint *ept;
-	const char *name = chinfo.name;
-	int cid;
-	int ret;
-
-	idr_for_each_entry(&glink->rcids, channel, cid) {
-		if (!strcmp(channel->name, name))
-			break;
-	}
-
-	if (!channel) {
-		channel = glink_rpm_create_local(glink, name);
-		if (IS_ERR(channel))
-			return NULL;
-	} else {
-		ret = glink_rpm_create_remote(glink, channel);
-		if (ret)
-			return NULL;
-	}
-
-	ept = &channel->ept;
-	ept->rpdev = rpdev;
-	ept->cb = cb;
-	ept->priv = priv;
-	ept->ops = &glink_endpoint_ops;
-
-	return ept;
-}
-
-static void glink_rpm_destroy_ept(struct rpmsg_endpoint *ept)
-{
-	struct glink_channel *channel = to_glink_channel(ept);
-	struct glink_rpm *glink = channel->glink;
-	unsigned long flags;
-
-	spin_lock_irqsave(&channel->recv_lock, flags);
-	channel->ept.cb = NULL;
-	spin_unlock_irqrestore(&channel->recv_lock, flags);
-
-	/* Decouple the potential rpdev from the channel */
-	channel->rpdev = NULL;
-
-	glink_rpm_send_close_req(glink, channel);
-}
-
-static int __glink_rpm_send(struct glink_channel *channel,
-			     void *data, int len, bool wait)
-{
-	struct glink_rpm *glink = channel->glink;
-	struct {
-		struct glink_msg msg;
-		__le32 chunk_size;
-		__le32 left_size;
-	} __packed req;
-
-	if (WARN(len % 8, "RPM GLINK expects 8 byte aligned messages\n"))
-		return -EINVAL;
-
-	req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
-	req.msg.param1 = cpu_to_le16(channel->lcid);
-	req.msg.param2 = cpu_to_le32(channel->rcid);
-	req.chunk_size = cpu_to_le32(len);
-	req.left_size = cpu_to_le32(0);
-
-	return glink_rpm_tx(glink, &req, sizeof(req), data, len, wait);
-}
-
-static int glink_rpm_send(struct rpmsg_endpoint *ept, void *data, int len)
-{
-	struct glink_channel *channel = to_glink_channel(ept);
-
-	return __glink_rpm_send(channel, data, len, true);
-}
-
-static int glink_rpm_trysend(struct rpmsg_endpoint *ept, void *data, int len)
-{
-	struct glink_channel *channel = to_glink_channel(ept);
-
-	return __glink_rpm_send(channel, data, len, false);
-}
-
-/*
- * Finds the device_node for the glink child interested in this channel.
- */
-static struct device_node *glink_rpm_match_channel(struct device_node *node,
-						    const char *channel)
-{
-	struct device_node *child;
-	const char *name;
-	const char *key;
-	int ret;
-
-	for_each_available_child_of_node(node, child) {
-		key = "qcom,glink-channels";
-		ret = of_property_read_string(child, key, &name);
-		if (ret)
-			continue;
-
-		if (strcmp(name, channel) == 0)
-			return child;
-	}
-
-	return NULL;
-}
-
-static const struct rpmsg_device_ops glink_device_ops = {
-	.create_ept = glink_rpm_create_ept,
-};
-
-static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
-	.destroy_ept = glink_rpm_destroy_ept,
-	.send = glink_rpm_send,
-	.trysend = glink_rpm_trysend,
-};
-
-static void glink_rpm_rpdev_release(struct device *dev)
-{
-	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
-	struct glink_channel *channel = to_glink_channel(rpdev->ept);
-
-	channel->rpdev = NULL;
-	kfree(rpdev);
-}
-
-static int glink_rpm_rx_open(struct glink_rpm *glink, unsigned int rcid,
-			     char *name)
-{
-	struct glink_channel *channel;
-	struct rpmsg_device *rpdev;
-	bool create_device = false;
-	int lcid;
-	int ret;
-
-	idr_for_each_entry(&glink->lcids, channel, lcid) {
-		if (!strcmp(channel->name, name))
-			break;
-	}
-
-	if (!channel) {
-		channel = glink_rpm_alloc_channel(glink, name);
-		if (IS_ERR(channel))
-			return PTR_ERR(channel);
-
-		/* The opening dance was initiated by the remote */
-		create_device = true;
-	}
-
-	mutex_lock(&glink->idr_lock);
-	ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_KERNEL);
-	if (ret < 0) {
-		dev_err(glink->dev, "Unable to insert channel into rcid list\n");
-		mutex_unlock(&glink->idr_lock);
-		goto free_channel;
-	}
-	channel->rcid = ret;
-	mutex_unlock(&glink->idr_lock);
-
-	complete(&channel->open_req);
-
-	if (create_device) {
-		rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
-		if (!rpdev) {
-			ret = -ENOMEM;
-			goto rcid_remove;
-		}
-
-		rpdev->ept = &channel->ept;
-		strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
-		rpdev->src = RPMSG_ADDR_ANY;
-		rpdev->dst = RPMSG_ADDR_ANY;
-		rpdev->ops = &glink_device_ops;
-
-		rpdev->dev.of_node = glink_rpm_match_channel(glink->dev->of_node, name);
-		rpdev->dev.parent = glink->dev;
-		rpdev->dev.release = glink_rpm_rpdev_release;
-
-		ret = rpmsg_register_device(rpdev);
-		if (ret)
-			goto free_rpdev;
-
-		channel->rpdev = rpdev;
-	}
-
-	return 0;
-
-free_rpdev:
-	kfree(rpdev);
-rcid_remove:
-	mutex_lock(&glink->idr_lock);
-	idr_remove(&glink->rcids, channel->rcid);
-	channel->rcid = 0;
-	mutex_unlock(&glink->idr_lock);
-free_channel:
-	/* Release the reference, iff we took it */
-	if (create_device)
-		kref_put(&channel->refcount, glink_rpm_channel_release);
-
-	return ret;
-}
-
-static void glink_rpm_rx_close(struct glink_rpm *glink, unsigned int rcid)
-{
-	struct rpmsg_channel_info chinfo;
-	struct glink_channel *channel;
-
-	channel = idr_find(&glink->rcids, rcid);
-	if (WARN(!channel, "close request on unknown channel\n"))
-		return;
-
-	if (channel->rpdev) {
-		strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
-		chinfo.src = RPMSG_ADDR_ANY;
-		chinfo.dst = RPMSG_ADDR_ANY;
-
-		rpmsg_unregister_device(glink->dev, &chinfo);
-	}
-
-	glink_rpm_send_close_ack(glink, channel->rcid);
-
-	mutex_lock(&glink->idr_lock);
-	idr_remove(&glink->rcids, channel->rcid);
-	channel->rcid = 0;
-	mutex_unlock(&glink->idr_lock);
-
-	kref_put(&channel->refcount, glink_rpm_channel_release);
-}
-
-static void glink_rpm_rx_close_ack(struct glink_rpm *glink, unsigned int lcid)
-{
-	struct glink_channel *channel;
-
-	channel = idr_find(&glink->lcids, lcid);
-	if (WARN(!channel, "close ack on unknown channel\n"))
-		return;
-
-	mutex_lock(&glink->idr_lock);
-	idr_remove(&glink->lcids, channel->lcid);
-	channel->lcid = 0;
-	mutex_unlock(&glink->idr_lock);
-
-	kref_put(&channel->refcount, glink_rpm_channel_release);
-}
-
-static void glink_rpm_work(struct work_struct *work)
-{
-	struct glink_rpm *glink = container_of(work, struct glink_rpm, rx_work);
-	struct glink_defer_cmd *dcmd;
-	struct glink_msg *msg;
-	unsigned long flags;
-	unsigned int param1;
-	unsigned int param2;
-	unsigned int cmd;
-
-	for (;;) {
-		spin_lock_irqsave(&glink->rx_lock, flags);
-		if (list_empty(&glink->rx_queue)) {
-			spin_unlock_irqrestore(&glink->rx_lock, flags);
-			break;
-		}
-		dcmd = list_first_entry(&glink->rx_queue, struct glink_defer_cmd, node);
-		list_del(&dcmd->node);
-		spin_unlock_irqrestore(&glink->rx_lock, flags);
-
-		msg = &dcmd->msg;
-		cmd = le16_to_cpu(msg->cmd);
-		param1 = le16_to_cpu(msg->param1);
-		param2 = le32_to_cpu(msg->param2);
-
-		switch (cmd) {
-		case RPM_CMD_VERSION:
-			glink_rpm_send_version_ack(glink);
-			break;
-		case RPM_CMD_VERSION_ACK:
-			break;
-		case RPM_CMD_OPEN:
-			glink_rpm_rx_open(glink, param1, msg->data);
-			break;
-		case RPM_CMD_CLOSE:
-			glink_rpm_rx_close(glink, param1);
-			break;
-		case RPM_CMD_CLOSE_ACK:
-			glink_rpm_rx_close_ack(glink, param1);
-			break;
-		default:
-			WARN(1, "Unknown defer object %d\n", cmd);
-			break;
-		}
-
-		kfree(dcmd);
-	}
 }
 
 static int glink_rpm_parse_toc(struct device *dev,
···
 
 		switch (id) {
 		case RPM_RX_FIFO_ID:
-			rx->length = size;
+			rx->native.length = size;
 
 			rx->tail = msg_ram + offset;
 			rx->head = msg_ram + offset + sizeof(u32);
 			rx->fifo = msg_ram + offset + 2 * sizeof(u32);
 			break;
 		case RPM_TX_FIFO_ID:
-			tx->length = size;
+			tx->native.length = size;
 
 			tx->tail = msg_ram + offset;
 			tx->head = msg_ram + offset + sizeof(u32);
···
 
 static int glink_rpm_probe(struct platform_device *pdev)
 {
-	struct glink_rpm *glink;
+	struct qcom_glink *glink;
+	struct glink_rpm_pipe *rx_pipe;
+	struct glink_rpm_pipe *tx_pipe;
 	struct device_node *np;
 	void __iomem *msg_ram;
 	size_t msg_ram_size;
 	struct device *dev = &pdev->dev;
 	struct resource r;
-	int irq;
 	int ret;
 
-	glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
-	if (!glink)
+	rx_pipe = devm_kzalloc(&pdev->dev, sizeof(*rx_pipe), GFP_KERNEL);
+	tx_pipe = devm_kzalloc(&pdev->dev, sizeof(*tx_pipe), GFP_KERNEL);
+	if (!rx_pipe || !tx_pipe)
 		return -ENOMEM;
-
-	glink->dev = dev;
-
-	mutex_init(&glink->tx_lock);
-	spin_lock_init(&glink->rx_lock);
-	INIT_LIST_HEAD(&glink->rx_queue);
-	INIT_WORK(&glink->rx_work, glink_rpm_work);
-
-	mutex_init(&glink->idr_lock);
-	idr_init(&glink->lcids);
-	idr_init(&glink->rcids);
-
-	glink->mbox_client.dev = &pdev->dev;
-	glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
-	if (IS_ERR(glink->mbox_chan)) {
-		if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "failed to acquire IPC channel\n");
-		return PTR_ERR(glink->mbox_chan);
-	}
 
 	np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", 0);
 	ret = of_address_to_resource(np, 0, &r);
···
 		return -ENOMEM;
 
 	ret = glink_rpm_parse_toc(dev, msg_ram, msg_ram_size,
-				  &glink->rx_pipe, &glink->tx_pipe);
+				  rx_pipe, tx_pipe);
 	if (ret)
 		return ret;
 
-	writel(0, glink->tx_pipe.head);
-	writel(0, glink->rx_pipe.tail);
+	/* Pipe specific accessors */
+	rx_pipe->native.avail = glink_rpm_rx_avail;
+	rx_pipe->native.peak = glink_rpm_rx_peak;
+	rx_pipe->native.advance = glink_rpm_rx_advance;
+	tx_pipe->native.avail = glink_rpm_tx_avail;
+	tx_pipe->native.write = glink_rpm_tx_write;
 
-	irq = platform_get_irq(pdev, 0);
-	ret = devm_request_irq(dev, irq,
-			       glink_rpm_intr,
-			       IRQF_NO_SUSPEND | IRQF_SHARED,
-			       "glink-rpm", glink);
-	if (ret) {
-		dev_err(dev, "Failed to request IRQ\n");
-		return ret;
-	}
+	writel(0, tx_pipe->head);
+	writel(0, rx_pipe->tail);
 
-	glink->irq = irq;
-
-	ret = glink_rpm_send_version(glink);
-	if (ret)
-		return ret;
+	glink = qcom_glink_native_probe(&pdev->dev,
+					0,
+					&rx_pipe->native,
+					&tx_pipe->native,
+					true);
+	if (IS_ERR(glink))
+		return PTR_ERR(glink);
 
 	platform_set_drvdata(pdev, glink);
 
 	return 0;
 }
 
-static int glink_rpm_remove_device(struct device *dev, void *data)
-{
-	device_unregister(dev);
-
-	return 0;
-}
-
 static int glink_rpm_remove(struct platform_device *pdev)
 {
-	struct glink_rpm *glink = platform_get_drvdata(pdev);
-	struct glink_channel *channel;
-	int cid;
-	int ret;
+	struct qcom_glink *glink = platform_get_drvdata(pdev);
 
-	disable_irq(glink->irq);
-	cancel_work_sync(&glink->rx_work);
-
-	ret = device_for_each_child(glink->dev, NULL, glink_rpm_remove_device);
-	if (ret)
-		dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
-
-	/* Release any defunct local channels, waiting for close-ack */
-	idr_for_each_entry(&glink->lcids, channel, cid)
-		kref_put(&channel->refcount, glink_rpm_channel_release);
-
-	idr_destroy(&glink->lcids);
-	idr_destroy(&glink->rcids);
+	qcom_glink_native_remove(glink);
 
 	return 0;
 }

drivers/rpmsg/qcom_glink_smem.c

···
+/*
+ * Copyright (c) 2016, Linaro Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/slab.h>
+#include <linux/rpmsg.h>
+#include <linux/idr.h>
+#include <linux/circ_buf.h>
+#include <linux/soc/qcom/smem.h>
+#include <linux/sizes.h>
+#include <linux/delay.h>
+#include <linux/regmap.h>
+#include <linux/workqueue.h>
+#include <linux/list.h>
+
+#include <linux/delay.h>
+#include <linux/rpmsg.h>
+#include <linux/rpmsg/qcom_glink.h>
+
+#include "qcom_glink_native.h"
+
+#define FIFO_FULL_RESERVE 8
+#define FIFO_ALIGNMENT 8
+#define TX_BLOCKED_CMD_RESERVE 8 /* size of struct read_notif_request */
+
+#define SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR	478
+#define SMEM_GLINK_NATIVE_XPRT_FIFO_0		479
+#define SMEM_GLINK_NATIVE_XPRT_FIFO_1		480
+
+struct glink_smem_pipe {
+	struct qcom_glink_pipe native;
+
+	__le32 *tail;
+	__le32 *head;
+
+	void *fifo;
+
+	int remote_pid;
+};
+
+#define to_smem_pipe(p) container_of(p, struct glink_smem_pipe, native)
+
+static size_t glink_smem_rx_avail(struct qcom_glink_pipe *np)
+{
+	struct glink_smem_pipe *pipe = to_smem_pipe(np);
+	size_t len;
+	void *fifo;
+	u32 head;
+	u32 tail;
+
+	if (!pipe->fifo) {
+		fifo = qcom_smem_get(pipe->remote_pid,
+				     SMEM_GLINK_NATIVE_XPRT_FIFO_1, &len);
+		if (IS_ERR(fifo)) {
+			pr_err("failed to acquire RX fifo handle: %ld\n",
+			       PTR_ERR(fifo));
+			return 0;
+		}
+
+		pipe->fifo = fifo;
+		pipe->native.length = len;
+	}
+
+	head = le32_to_cpu(*pipe->head);
+	tail = le32_to_cpu(*pipe->tail);
+
+	if (head < tail)
+		return pipe->native.length - tail + head;
+	else
+		return head - tail;
+}
+
+static void glink_smem_rx_peak(struct qcom_glink_pipe *np,
+			       void *data, unsigned int offset, size_t count)
+{
+	struct glink_smem_pipe *pipe = to_smem_pipe(np);
+	size_t len;
+	u32 tail;
+
+	tail = le32_to_cpu(*pipe->tail);
+	tail += offset;
+	if (tail >= pipe->native.length)
+		tail -= pipe->native.length;
+
+	len = min_t(size_t, count, pipe->native.length - tail);
+	if (len) {
+		__ioread32_copy(data, pipe->fifo + tail,
+				len / sizeof(u32));
+	}
+
+	if (len != count) {
+		__ioread32_copy(data + len, pipe->fifo,
+				(count - len) / sizeof(u32));
+	}
+}
+
+static void glink_smem_rx_advance(struct qcom_glink_pipe *np,
+				  size_t count)
+{
+	struct glink_smem_pipe *pipe = to_smem_pipe(np);
+	u32 tail;
+
+	tail = le32_to_cpu(*pipe->tail);
+
+	tail += count;
+	if (tail > pipe->native.length)
+		tail -= pipe->native.length;
+
+	*pipe->tail = cpu_to_le32(tail);
+}
+
+static size_t glink_smem_tx_avail(struct qcom_glink_pipe *np)
+{
+	struct glink_smem_pipe *pipe = to_smem_pipe(np);
+	u32 head;
+	u32 tail;
+	u32 avail;
+
+	head = le32_to_cpu(*pipe->head);
+	tail = le32_to_cpu(*pipe->tail);
+
+	if (tail <= head)
+		avail = pipe->native.length - head + tail;
+	else
+		avail = tail - head;
+
+	if (avail < (FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE))
+		avail = 0;
+	else
+		avail -= FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE;
+
+	return avail;
+}
+
+static unsigned int glink_smem_tx_write_one(struct glink_smem_pipe *pipe,
+					    unsigned int head,
+					    const void *data, size_t count)
+{
+	size_t len;
+
+	len = min_t(size_t, count, pipe->native.length - head);
+	if (len)
+		memcpy(pipe->fifo + head, data, len);
+
+	if (len != count)
+		memcpy(pipe->fifo, data + len, count - len);
+
+	head += count;
+	if (head >= pipe->native.length)
+		head -= pipe->native.length;
+
+	return head;
+}
+
+static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe,
+				const void *hdr, size_t hlen,
+				const void *data, size_t dlen)
+{
+	struct glink_smem_pipe *pipe = to_smem_pipe(glink_pipe);
+	unsigned int head;
+
+	head = le32_to_cpu(*pipe->head);
+
+	head = glink_smem_tx_write_one(pipe, head, hdr, hlen);
+	head = glink_smem_tx_write_one(pipe, head, data, dlen);
+
+	/* Ensure head is always aligned to 8 bytes */
+	head = ALIGN(head, 8);
+	if (head >= pipe->native.length)
+		head -= pipe->native.length;
+
+	*pipe->head = cpu_to_le32(head);
+}
+
+static void qcom_glink_smem_release(struct device *dev)
+{
+	kfree(dev);
+}
+
+struct qcom_glink *qcom_glink_smem_register(struct device *parent,
+					    struct device_node *node)
+{
+	struct glink_smem_pipe *rx_pipe;
+	struct glink_smem_pipe *tx_pipe;
+	struct qcom_glink *glink;
+	struct device *dev;
+	u32 remote_pid;
+	__le32 *descs;
+	size_t size;
+	int ret;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	dev->parent = parent;
+	dev->of_node = node;
+	dev->release = qcom_glink_smem_release;
+	dev_set_name(dev, "%s:%s", node->parent->name, node->name);
+	ret = device_register(dev);
+	if (ret) {
+		pr_err("failed to register glink edge\n");
+		return ERR_PTR(ret);
+	}
+
+	ret = of_property_read_u32(dev->of_node, "qcom,remote-pid",
+				   &remote_pid);
+	if (ret) {
+		dev_err(dev, "failed to parse qcom,remote-pid\n");
+		goto err_put_dev;
+	}
+
+	rx_pipe = devm_kzalloc(dev, sizeof(*rx_pipe), GFP_KERNEL);
+	tx_pipe = devm_kzalloc(dev, sizeof(*tx_pipe), GFP_KERNEL);
+	if (!rx_pipe || !tx_pipe) {
+		ret = -ENOMEM;
+		goto err_put_dev;
+	}
+
+	ret = qcom_smem_alloc(remote_pid,
+			      SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, 32);
+	if (ret && ret != -EEXIST) {
+		dev_err(dev, "failed to allocate glink descriptors\n");
+		goto err_put_dev;
+	}
+
+	descs = qcom_smem_get(remote_pid,
+			      SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, &size);
+	if (IS_ERR(descs)) {
+		dev_err(dev, "failed to acquire xprt descriptor\n");
+		ret = PTR_ERR(descs);
+		goto err_put_dev;
+	}
+
+	if (size != 32) {
+		dev_err(dev, "glink descriptor of invalid size\n");
+		ret = -EINVAL;
+		goto err_put_dev;
+	}
+
+	tx_pipe->tail = &descs[0];
+	tx_pipe->head = &descs[1];
+	rx_pipe->tail = &descs[2];
+	rx_pipe->head = &descs[3];
+
+	ret = qcom_smem_alloc(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
+			      SZ_16K);
+	if (ret && ret != -EEXIST) {
+		dev_err(dev, "failed to allocate TX fifo\n");
+		goto err_put_dev;
+	}
+
+	tx_pipe->fifo = qcom_smem_get(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
+				      &tx_pipe->native.length);
+	if (IS_ERR(tx_pipe->fifo)) {
+		dev_err(dev, "failed to acquire TX fifo\n");
+		ret = PTR_ERR(tx_pipe->fifo);
+		goto err_put_dev;
+	}
+
+	rx_pipe->native.avail = glink_smem_rx_avail;
+	rx_pipe->native.peak = glink_smem_rx_peak;
+	rx_pipe->native.advance = glink_smem_rx_advance;
+	rx_pipe->remote_pid = remote_pid;
+
+	tx_pipe->native.avail = glink_smem_tx_avail;
+	tx_pipe->native.write = glink_smem_tx_write;
+	tx_pipe->remote_pid = remote_pid;
+
+	*rx_pipe->tail = 0;
+	*tx_pipe->head = 0;
+
+	glink = qcom_glink_native_probe(dev,
+					GLINK_FEATURE_INTENT_REUSE,
+					&rx_pipe->native, &tx_pipe->native,
+					false);
+	if (IS_ERR(glink)) {
+		ret = PTR_ERR(glink);
+		goto err_put_dev;
+	}
+
+	return glink;
+
+err_put_dev:
+	put_device(dev);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(qcom_glink_smem_register);
+
+void qcom_glink_smem_unregister(struct qcom_glink *glink)
+{
+	qcom_glink_native_remove(glink);
+	qcom_glink_native_unregister(glink);
+}
+EXPORT_SYMBOL_GPL(qcom_glink_smem_unregister);
+
+MODULE_AUTHOR("Bjorn Andersson <[e-mail]>");
+MODULE_DESCRIPTION("Qualcomm GLINK SMEM driver");
+MODULE_LICENSE("GPL v2");

drivers/rpmsg/qcom_smd.c

···
 
 	edge->dev.parent = parent;
 	edge->dev.release = qcom_smd_edge_release;
+	edge->dev.of_node = node;
 	edge->dev.groups = qcom_smd_edge_groups;
 	dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name);
 	ret = device_register(&edge->dev);

drivers/rpmsg/virtio_rpmsg_bus.c

···
  * @rbufs:	kernel address of rx buffers
  * @sbufs:	kernel address of tx buffers
  * @num_bufs:	total number of buffers for rx and tx
+ * @buf_size:   size of one rx or tx buffer
  * @last_sbuf:	index of last tx buffer used
  * @bufs_dma:	dma base addr of the buffers
  * @tx_lock:	protects svq, sbufs and sleepers, to allow concurrent senders.
···
 	struct virtqueue *rvq, *svq;
 	void *rbufs, *sbufs;
 	unsigned int num_bufs;
+	unsigned int buf_size;
 	int last_sbuf;
 	dma_addr_t bufs_dma;
 	struct mutex tx_lock;
···
  * processor.
  */
 #define MAX_RPMSG_NUM_BUFS	(512)
-#define RPMSG_BUF_SIZE		(512)
+#define MAX_RPMSG_BUF_SIZE	(512)
 
 /*
  * Local addresses are dynamically allocated on-demand.
···
 	.trysendto = virtio_rpmsg_trysendto,
 	.trysend_offchannel = virtio_rpmsg_trysend_offchannel,
 };
+
+/**
+ * rpmsg_sg_init - initialize scatterlist according to cpu address location
+ * @sg: scatterlist to fill
+ * @cpu_addr: virtual address of the buffer
+ * @len: buffer length
+ *
+ * An internal function filling scatterlist according to virtual address
+ * location (in vmalloc or in kernel).
+ */
+static void
+rpmsg_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len)
+{
+	if (is_vmalloc_addr(cpu_addr)) {
+		sg_init_table(sg, 1);
+		sg_set_page(sg, vmalloc_to_page(cpu_addr), len,
+			    offset_in_page(cpu_addr));
+	} else {
+		WARN_ON(!virt_addr_valid(cpu_addr));
+		sg_init_one(sg, cpu_addr, len);
+	}
+}
 
 /**
  * __ept_release() - deallocate an rpmsg endpoint
···
 	 * (half of our buffers are used for sending messages)
 	 */
 	if (vrp->last_sbuf < vrp->num_bufs / 2)
-		ret = vrp->sbufs + RPMSG_BUF_SIZE * vrp->last_sbuf++;
+		ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++;
 	/* or recycle a used one */
 	else
 		ret = virtqueue_get_buf(vrp->svq, &len);
···
 	 * messaging), or to improve the buffer allocator, to support
 	 * variable-length buffer sizes.
 	 */
-	if (len > RPMSG_BUF_SIZE - sizeof(struct rpmsg_hdr)) {
+	if (len > vrp->buf_size - sizeof(struct rpmsg_hdr)) {
 		dev_err(dev, "message is too big (%d)\n", len);
 		return -EMSGSIZE;
 	}
···
 			 msg, sizeof(*msg) + msg->len, true);
 #endif
 
-	sg_init_one(&sg, msg, sizeof(*msg) + len);
+	rpmsg_sg_init(&sg, msg, sizeof(*msg) + len);
 
 	mutex_lock(&vrp->tx_lock);
 
···
 	mutex_unlock(&vrp->tx_lock);
 	return err;
 }
-EXPORT_SYMBOL(rpmsg_send_offchannel_raw);
 
 static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
 {
···
 	 * We currently use fixed-sized buffers, so trivially sanitize
 	 * the reported payload length.
 	 */
-	if (len > RPMSG_BUF_SIZE ||
+	if (len > vrp->buf_size ||
 	    msg->len > (len - sizeof(struct rpmsg_hdr))) {
 		dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg->len);
 		return -EINVAL;
···
 		dev_warn(dev, "msg received with no recipient\n");
 
 	/* publish the real size of the buffer */
-	sg_init_one(&sg, msg, RPMSG_BUF_SIZE);
+	rpmsg_sg_init(&sg, msg, vrp->buf_size);
 
 	/* add the buffer back to the remote processor's virtqueue */
 	err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL);
···
 	else
 		vrp->num_bufs = MAX_RPMSG_NUM_BUFS;
 
-	total_buf_space = vrp->num_bufs * RPMSG_BUF_SIZE;
+	vrp->buf_size = MAX_RPMSG_BUF_SIZE;
+
+	total_buf_space = vrp->num_bufs * vrp->buf_size;
 
 	/* allocate coherent memory for the buffers */
 	bufs_va = dma_alloc_coherent(vdev->dev.parent->parent,
···
 	/* set up the receive buffers */
 	for (i = 0; i < vrp->num_bufs / 2; i++) {
 		struct scatterlist sg;
-		void *cpu_addr = vrp->rbufs + i * RPMSG_BUF_SIZE;
+		void *cpu_addr = vrp->rbufs + i * vrp->buf_size;
 
-		sg_init_one(&sg, cpu_addr, RPMSG_BUF_SIZE);
+		rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size);
 
 		err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr,
 					  GFP_KERNEL);
···
 static void rpmsg_remove(struct virtio_device *vdev)
 {
 	struct virtproc_info *vrp = vdev->priv;
-	size_t total_buf_space = vrp->num_bufs * RPMSG_BUF_SIZE;
+	size_t total_buf_space = vrp->num_bufs * vrp->buf_size;
 	int ret;
 
 	vdev->config->reset(vdev);

include/linux/rpmsg/qcom_glink.h

···
+#ifndef _LINUX_RPMSG_QCOM_GLINK_H
+#define _LINUX_RPMSG_QCOM_GLINK_H
+
+#include <linux/device.h>
+
+struct qcom_glink;
+
+#if IS_ENABLED(CONFIG_RPMSG_QCOM_GLINK_SMEM)
+
+struct qcom_glink *qcom_glink_smem_register(struct device *parent,
+					    struct device_node *node);
+void qcom_glink_smem_unregister(struct qcom_glink *glink);
+
+#else
+
+static inline struct qcom_glink *
+qcom_glink_smem_register(struct device *parent,
+			 struct device_node *node)
+{
+	return NULL;
+}
+
+static inline void qcom_glink_smem_unregister(struct qcom_glink *glink) {}
+
+#endif
+
+#endif