Merge tag 'rpmsg-for-3.4' of...

Merge tag 'rpmsg-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc into next/rpmsg

* tag 'rpmsg-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc:
  remoteproc: s/big switch/lookup table/
  remoteproc: bail out if firmware has different endianess
  remoteproc: don't use virtio's weak barriers
  rpmsg: rename virtqueue_add_buf_gfp to virtqueue_add_buf
  rpmsg: depend on EXPERIMENTAL
  remoteproc: depend on EXPERIMENTAL
  rpmsg: add Kconfig menu
  remoteproc: add Kconfig menu
  remoteproc: look for truncated firmware images
  remoteproc/omap: utilize module_platform_driver
  remoteproc: remove unused resource type
  remoteproc: avoid registering a virtio device if not supported
  remoteproc: do not require an iommu
  samples/rpmsg: add an rpmsg driver sample
  rpmsg: add virtio-based remote processor messaging bus
  remoteproc/omap: add a remoteproc driver for OMAP4
  remoteproc: create rpmsg virtio device
  remoteproc: add debugfs entries
  remoteproc: add framework for controlling remote processors

Documentation/ABI/testing/sysfs-bus-rpmsg

+What:		/sys/bus/rpmsg/devices/.../name
+Date:		June 2011
+KernelVersion:	3.3
+Contact:	Ohad Ben-Cohen <ohad@wizery.com>
+Description:
+		Every rpmsg device is a communication channel with a remote
+		processor. Channels are identified with a (textual) name,
+		which is maximum 32 bytes long (defined as RPMSG_NAME_SIZE in
+		rpmsg.h).
+
+		This sysfs entry contains the name of this channel.
+
+What:		/sys/bus/rpmsg/devices/.../src
+Date:		June 2011
+KernelVersion:	3.3
+Contact:	Ohad Ben-Cohen <ohad@wizery.com>
+Description:
+		Every rpmsg device is a communication channel with a remote
+		processor. Channels have a local ("source") rpmsg address,
+		and remote ("destination") rpmsg address. When an entity
+		starts listening on one end of a channel, it assigns it with
+		a unique rpmsg address (a 32 bits integer). This way when
+		inbound messages arrive to this address, the rpmsg core
+		dispatches them to the listening entity (a kernel driver).
+
+		This sysfs entry contains the src (local) rpmsg address
+		of this channel. If it contains 0xffffffff, then an address
+		wasn't assigned (can happen if no driver exists for this
+		channel).
+
+What:		/sys/bus/rpmsg/devices/.../dst
+Date:		June 2011
+KernelVersion:	3.3
+Contact:	Ohad Ben-Cohen <ohad@wizery.com>
+Description:
+		Every rpmsg device is a communication channel with a remote
+		processor. Channels have a local ("source") rpmsg address,
+		and remote ("destination") rpmsg address. When an entity
+		starts listening on one end of a channel, it assigns it with
+		a unique rpmsg address (a 32 bits integer). This way when
+		inbound messages arrive to this address, the rpmsg core
+		dispatches them to the listening entity.
+
+		This sysfs entry contains the dst (remote) rpmsg address
+		of this channel. If it contains 0xffffffff, then an address
+		wasn't assigned (can happen if the kernel driver that
+		is attached to this channel is exposing a service to the
+		remote processor. This make it a local rpmsg server,
+		and it is listening for inbound messages that may be sent
+		from any remote rpmsg client; it is not bound to a single
+		remote entity).
+
+What:		/sys/bus/rpmsg/devices/.../announce
+Date:		June 2011
+KernelVersion:	3.3
+Contact:	Ohad Ben-Cohen <ohad@wizery.com>
+Description:
+		Every rpmsg device is a communication channel with a remote
+		processor. Channels are identified by a textual name (see
+		/sys/bus/rpmsg/devices/.../name above) and have a local
+		("source") rpmsg address, and remote ("destination") rpmsg
+		address.
+
+		A channel is first created when an entity, whether local
+		or remote, starts listening on it for messages (and is thus
+		called an rpmsg server).
+
+		When that happens, a "name service" announcement is sent
+		to the other processor, in order to let it know about the
+		creation of the channel (this way remote clients know they
+		can start sending messages).
+
+		This sysfs entry tells us whether the channel is a local
+		server channel that is announced (values are either
+		true or false).

MAINTAINERS

@@ -5550,6 +5550,13 @@ S:	Supported
 F:	drivers/base/regmap/
 F:	include/linux/regmap.h
 
+REMOTE PROCESSOR (REMOTEPROC) SUBSYSTEM
+M:	Ohad Ben-Cohen <ohad@wizery.com>
+S:	Maintained
+F:	drivers/remoteproc/
+F:	Documentation/remoteproc.txt
+F:	include/linux/remoteproc.txt
+
 RFKILL
 M:	Johannes Berg <johannes@sipsolutions.net>
 L:	linux-wireless@vger.kernel.org

arch/arm/plat-omap/include/plat/remoteproc.h

+/*
+ * Remote Processor - omap-specific bits
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * 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 _PLAT_REMOTEPROC_H
+#define _PLAT_REMOTEPROC_H
+
+struct rproc_ops;
+struct platform_device;
+
+/*
+ * struct omap_rproc_pdata - omap remoteproc's platform data
+ * @name: the remoteproc's name
+ * @oh_name: omap hwmod device
+ * @oh_name_opt: optional, secondary omap hwmod device
+ * @firmware: name of firmware file to load
+ * @mbox_name: name of omap mailbox device to use with this rproc
+ * @ops: start/stop rproc handlers
+ * @device_enable: omap-specific handler for enabling a device
+ * @device_shutdown: omap-specific handler for shutting down a device
+ */
+struct omap_rproc_pdata {
+	const char *name;
+	const char *oh_name;
+	const char *oh_name_opt;
+	const char *firmware;
+	const char *mbox_name;
+	const struct rproc_ops *ops;
+	int (*device_enable) (struct platform_device *pdev);
+	int (*device_shutdown) (struct platform_device *pdev);
+};
+
+#if defined(CONFIG_OMAP_REMOTEPROC) || defined(CONFIG_OMAP_REMOTEPROC_MODULE)
+
+void __init omap_rproc_reserve_cma(void);
+
+#else
+
+void __init omap_rproc_reserve_cma(void)
+{
+}
+
+#endif
+
+#endif /* _PLAT_REMOTEPROC_H */

drivers/Kconfig

@@ -132,6 +132,10 @@ source "drivers/clocksource/Kconfig"
 
 source "drivers/iommu/Kconfig"
 
+source "drivers/remoteproc/Kconfig"
+
+source "drivers/rpmsg/Kconfig"
+
 source "drivers/virt/Kconfig"
 
 source "drivers/devfreq/Kconfig"

drivers/Makefile

@@ -126,6 +126,8 @@ obj-y				+= clk/
 obj-$(CONFIG_HWSPINLOCK)	+= hwspinlock/
 obj-$(CONFIG_NFC)		+= nfc/
 obj-$(CONFIG_IOMMU_SUPPORT)	+= iommu/
+obj-$(CONFIG_REMOTEPROC)	+= remoteproc/
+obj-$(CONFIG_RPMSG)		+= rpmsg/
 
 # Virtualization drivers
 obj-$(CONFIG_VIRT_DRIVERS)	+= virt/

drivers/remoteproc/Kconfig

+menu "Remoteproc drivers (EXPERIMENTAL)"
+
+# REMOTEPROC gets selected by whoever wants it
+config REMOTEPROC
+	tristate
+	depends on EXPERIMENTAL
+
+config OMAP_REMOTEPROC
+	tristate "OMAP remoteproc support"
+	depends on ARCH_OMAP4
+	select OMAP_IOMMU
+	select REMOTEPROC
+	select OMAP_MBOX_FWK
+	select RPMSG
+	default m
+	help
+	  Say y here to support OMAP's remote processors (dual M3
+	  and DSP on OMAP4) via the remote processor framework.
+
+	  Currently only supported on OMAP4.
+
+	  Usually you want to say y here, in order to enable multimedia
+	  use-cases to run on your platform (multimedia codecs are
+	  offloaded to remote DSP processors using this framework).
+
+	  It's safe to say n here if you're not interested in multimedia
+	  offloading or just want a bare minimum kernel.
+
+endmenu

drivers/remoteproc/Makefile

+#
+# Generic framework for controlling remote processors
+#
+
+obj-$(CONFIG_REMOTEPROC)		+= remoteproc.o
+remoteproc-y				:= remoteproc_core.o
+remoteproc-y				+= remoteproc_debugfs.o
+remoteproc-y				+= remoteproc_rpmsg.o
+obj-$(CONFIG_OMAP_REMOTEPROC)		+= omap_remoteproc.o

drivers/remoteproc/omap_remoteproc.c

+/*
+ * OMAP Remote Processor driver
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Ohad Ben-Cohen <ohad@wizery.com>
+ * Brian Swetland <swetland@google.com>
+ * Fernando Guzman Lugo <fernando.lugo@ti.com>
+ * Mark Grosen <mgrosen@ti.com>
+ * Suman Anna <s-anna@ti.com>
+ * Hari Kanigeri <h-kanigeri2@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/remoteproc.h>
+
+#include <plat/mailbox.h>
+#include <plat/remoteproc.h>
+
+#include "omap_remoteproc.h"
+#include "remoteproc_internal.h"
+
+/**
+ * struct omap_rproc - omap remote processor state
+ * @mbox: omap mailbox handle
+ * @nb: notifier block that will be invoked on inbound mailbox messages
+ * @rproc: rproc handle
+ */
+struct omap_rproc {
+	struct omap_mbox *mbox;
+	struct notifier_block nb;
+	struct rproc *rproc;
+};
+
+/**
+ * omap_rproc_mbox_callback() - inbound mailbox message handler
+ * @this: notifier block
+ * @index: unused
+ * @data: mailbox payload
+ *
+ * This handler is invoked by omap's mailbox driver whenever a mailbox
+ * message is received. Usually, the mailbox payload simply contains
+ * the index of the virtqueue that is kicked by the remote processor,
+ * and we let remoteproc core handle it.
+ *
+ * In addition to virtqueue indices, we also have some out-of-band values
+ * that indicates different events. Those values are deliberately very
+ * big so they don't coincide with virtqueue indices.
+ */
+static int omap_rproc_mbox_callback(struct notifier_block *this,
+					unsigned long index, void *data)
+{
+	mbox_msg_t msg = (mbox_msg_t) data;
+	struct omap_rproc *oproc = container_of(this, struct omap_rproc, nb);
+	struct device *dev = oproc->rproc->dev;
+	const char *name = oproc->rproc->name;
+
+	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
+
+	switch (msg) {
+	case RP_MBOX_CRASH:
+		/* just log this for now. later, we'll also do recovery */
+		dev_err(dev, "omap rproc %s crashed\n", name);
+		break;
+	case RP_MBOX_ECHO_REPLY:
+		dev_info(dev, "received echo reply from %s\n", name);
+		break;
+	default:
+		/* ignore vq indices which are too large to be valid */
+		if (msg >= 2) {
+			dev_warn(dev, "invalid mbox msg: 0x%x\n", msg);
+			break;
+		}
+
+		/*
+		 * At this point, 'msg' contains the index of the vring
+		 * which was just triggered.
+		 */
+		if (rproc_vq_interrupt(oproc->rproc, msg) == IRQ_NONE)
+			dev_dbg(dev, "no message was found in vqid %d\n", msg);
+	}
+
+	return NOTIFY_DONE;
+}
+
+/* kick a virtqueue */
+static void omap_rproc_kick(struct rproc *rproc, int vqid)
+{
+	struct omap_rproc *oproc = rproc->priv;
+	int ret;
+
+	/* send the index of the triggered virtqueue in the mailbox payload */
+	ret = omap_mbox_msg_send(oproc->mbox, vqid);
+	if (ret)
+		dev_err(rproc->dev, "omap_mbox_msg_send failed: %d\n", ret);
+}
+
+/*
+ * Power up the remote processor.
+ *
+ * This function will be invoked only after the firmware for this rproc
+ * was loaded, parsed successfully, and all of its resource requirements
+ * were met.
+ */
+static int omap_rproc_start(struct rproc *rproc)
+{
+	struct omap_rproc *oproc = rproc->priv;
+	struct platform_device *pdev = to_platform_device(rproc->dev);
+	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
+	int ret;
+
+	oproc->nb.notifier_call = omap_rproc_mbox_callback;
+
+	/* every omap rproc is assigned a mailbox instance for messaging */
+	oproc->mbox = omap_mbox_get(pdata->mbox_name, &oproc->nb);
+	if (IS_ERR(oproc->mbox)) {
+		ret = PTR_ERR(oproc->mbox);
+		dev_err(rproc->dev, "omap_mbox_get failed: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Ping the remote processor. this is only for sanity-sake;
+	 * there is no functional effect whatsoever.
+	 *
+	 * Note that the reply will _not_ arrive immediately: this message
+	 * will wait in the mailbox fifo until the remote processor is booted.
+	 */
+	ret = omap_mbox_msg_send(oproc->mbox, RP_MBOX_ECHO_REQUEST);
+	if (ret) {
+		dev_err(rproc->dev, "omap_mbox_get failed: %d\n", ret);
+		goto put_mbox;
+	}
+
+	ret = pdata->device_enable(pdev);
+	if (ret) {
+		dev_err(rproc->dev, "omap_device_enable failed: %d\n", ret);
+		goto put_mbox;
+	}
+
+	return 0;
+
+put_mbox:
+	omap_mbox_put(oproc->mbox, &oproc->nb);
+	return ret;
+}
+
+/* power off the remote processor */
+static int omap_rproc_stop(struct rproc *rproc)
+{
+	struct platform_device *pdev = to_platform_device(rproc->dev);
+	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
+	struct omap_rproc *oproc = rproc->priv;
+	int ret;
+
+	ret = pdata->device_shutdown(pdev);
+	if (ret)
+		return ret;
+
+	omap_mbox_put(oproc->mbox, &oproc->nb);
+
+	return 0;
+}
+
+static struct rproc_ops omap_rproc_ops = {
+	.start		= omap_rproc_start,
+	.stop		= omap_rproc_stop,
+	.kick		= omap_rproc_kick,
+};
+
+static int __devinit omap_rproc_probe(struct platform_device *pdev)
+{
+	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
+	struct omap_rproc *oproc;
+	struct rproc *rproc;
+	int ret;
+
+	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(pdev->dev.parent, "dma_set_coherent_mask: %d\n", ret);
+		return ret;
+	}
+
+	rproc = rproc_alloc(&pdev->dev, pdata->name, &omap_rproc_ops,
+				pdata->firmware, sizeof(*oproc));
+	if (!rproc)
+		return -ENOMEM;
+
+	oproc = rproc->priv;
+	oproc->rproc = rproc;
+
+	platform_set_drvdata(pdev, rproc);
+
+	ret = rproc_register(rproc);
+	if (ret)
+		goto free_rproc;
+
+	return 0;
+
+free_rproc:
+	rproc_free(rproc);
+	return ret;
+}
+
+static int __devexit omap_rproc_remove(struct platform_device *pdev)
+{
+	struct rproc *rproc = platform_get_drvdata(pdev);
+
+	return rproc_unregister(rproc);
+}
+
+static struct platform_driver omap_rproc_driver = {
+	.probe = omap_rproc_probe,
+	.remove = __devexit_p(omap_rproc_remove),
+	.driver = {
+		.name = "omap-rproc",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(omap_rproc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("OMAP Remote Processor control driver");

drivers/remoteproc/omap_remoteproc.h

+/*
+ * Remote processor messaging
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011 Google, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in
+ *   the documentation and/or other materials provided with the
+ *   distribution.
+ * * Neither the name Texas Instruments nor the names of its
+ *   contributors may be used to endorse or promote products derived
+ *   from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _OMAP_RPMSG_H
+#define _OMAP_RPMSG_H
+
+/*
+ * enum - Predefined Mailbox Messages
+ *
+ * @RP_MBOX_READY: informs the M3's that we're up and running. this is
+ * part of the init sequence sent that the M3 expects to see immediately
+ * after it is booted.
+ *
+ * @RP_MBOX_PENDING_MSG: informs the receiver that there is an inbound
+ * message waiting in its own receive-side vring. please note that currently
+ * this message is optional: alternatively, one can explicitly send the index
+ * of the triggered virtqueue itself. the preferred approach will be decided
+ * as we progress and experiment with those two different approaches.
+ *
+ * @RP_MBOX_CRASH: this message is sent if BIOS crashes
+ *
+ * @RP_MBOX_ECHO_REQUEST: a mailbox-level "ping" message.
+ *
+ * @RP_MBOX_ECHO_REPLY: a mailbox-level reply to a "ping"
+ *
+ * @RP_MBOX_ABORT_REQUEST: a "please crash" request, used for testing the
+ * recovery mechanism (to some extent).
+ */
+enum omap_rp_mbox_messages {
+	RP_MBOX_READY		= 0xFFFFFF00,
+	RP_MBOX_PENDING_MSG	= 0xFFFFFF01,
+	RP_MBOX_CRASH		= 0xFFFFFF02,
+	RP_MBOX_ECHO_REQUEST	= 0xFFFFFF03,
+	RP_MBOX_ECHO_REPLY	= 0xFFFFFF04,
+	RP_MBOX_ABORT_REQUEST	= 0xFFFFFF05,
+};
+
+#endif /* _OMAP_RPMSG_H */

drivers/remoteproc/remoteproc_debugfs.c

+/*
+ * Remote Processor Framework
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Ohad Ben-Cohen <ohad@wizery.com>
+ * Mark Grosen <mgrosen@ti.com>
+ * Brian Swetland <swetland@google.com>
+ * Fernando Guzman Lugo <fernando.lugo@ti.com>
+ * Suman Anna <s-anna@ti.com>
+ * Robert Tivy <rtivy@ti.com>
+ * Armando Uribe De Leon <x0095078@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * 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.
+ */
+
+#define pr_fmt(fmt)    "%s: " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/debugfs.h>
+#include <linux/remoteproc.h>
+#include <linux/device.h>
+
+/* remoteproc debugfs parent dir */
+static struct dentry *rproc_dbg;
+
+/*
+ * Some remote processors may support dumping trace logs into a shared
+ * memory buffer. We expose this trace buffer using debugfs, so users
+ * can easily tell what's going on remotely.
+ *
+ * We will most probably improve the rproc tracing facilities later on,
+ * but this kind of lightweight and simple mechanism is always good to have,
+ * as it provides very early tracing with little to no dependencies at all.
+ */
+static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
+						size_t count, loff_t *ppos)
+{
+	struct rproc_mem_entry *trace = filp->private_data;
+	int len = strnlen(trace->va, trace->len);
+
+	return simple_read_from_buffer(userbuf, count, ppos, trace->va, len);
+}
+
+static int rproc_open_generic(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+
+	return 0;
+}
+
+static const struct file_operations trace_rproc_ops = {
+	.read = rproc_trace_read,
+	.open = rproc_open_generic,
+	.llseek	= generic_file_llseek,
+};
+
+/*
+ * A state-to-string lookup table, for exposing a human readable state
+ * via debugfs. Always keep in sync with enum rproc_state
+ */
+static const char * const rproc_state_string[] = {
+	"offline",
+	"suspended",
+	"running",
+	"crashed",
+	"invalid",
+};
+
+/* expose the state of the remote processor via debugfs */
+static ssize_t rproc_state_read(struct file *filp, char __user *userbuf,
+						size_t count, loff_t *ppos)
+{
+	struct rproc *rproc = filp->private_data;
+	unsigned int state;
+	char buf[30];
+	int i;
+
+	state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
+
+	i = snprintf(buf, 30, "%.28s (%d)\n", rproc_state_string[state],
+							rproc->state);
+
+	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
+}
+
+static const struct file_operations rproc_state_ops = {
+	.read = rproc_state_read,
+	.open = rproc_open_generic,
+	.llseek	= generic_file_llseek,
+};
+
+/* expose the name of the remote processor via debugfs */
+static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
+						size_t count, loff_t *ppos)
+{
+	struct rproc *rproc = filp->private_data;
+	/* need room for the name, a newline and a terminating null */
+	char buf[100];
+	int i;
+
+	i = snprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
+
+	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
+}
+
+static const struct file_operations rproc_name_ops = {
+	.read = rproc_name_read,
+	.open = rproc_open_generic,
+	.llseek	= generic_file_llseek,
+};
+
+void rproc_remove_trace_file(struct dentry *tfile)
+{
+	debugfs_remove(tfile);
+}
+
+struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
+					struct rproc_mem_entry *trace)
+{
+	struct dentry *tfile;
+
+	tfile = debugfs_create_file(name, 0400, rproc->dbg_dir,
+						trace, &trace_rproc_ops);
+	if (!tfile) {
+		dev_err(rproc->dev, "failed to create debugfs trace entry\n");
+		return NULL;
+	}
+
+	return tfile;
+}
+
+void rproc_delete_debug_dir(struct rproc *rproc)
+{
+	if (!rproc->dbg_dir)
+		return;
+
+	debugfs_remove_recursive(rproc->dbg_dir);
+}
+
+void rproc_create_debug_dir(struct rproc *rproc)
+{
+	struct device *dev = rproc->dev;
+
+	if (!rproc_dbg)
+		return;
+
+	rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
+	if (!rproc->dbg_dir)
+		return;
+
+	debugfs_create_file("name", 0400, rproc->dbg_dir,
+					rproc, &rproc_name_ops);
+	debugfs_create_file("state", 0400, rproc->dbg_dir,
+					rproc, &rproc_state_ops);
+}
+
+void __init rproc_init_debugfs(void)
+{
+	if (debugfs_initialized()) {
+		rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
+		if (!rproc_dbg)
+			pr_err("can't create debugfs dir\n");
+	}
+}
+
+void __exit rproc_exit_debugfs(void)
+{
+	if (rproc_dbg)
+		debugfs_remove(rproc_dbg);
+}

drivers/remoteproc/remoteproc_internal.h

+/*
+ * Remote processor framework
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Ohad Ben-Cohen <ohad@wizery.com>
+ * Brian Swetland <swetland@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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 REMOTEPROC_INTERNAL_H
+#define REMOTEPROC_INTERNAL_H
+
+#include <linux/irqreturn.h>
+
+struct rproc;
+
+/* from remoteproc_core.c */
+void rproc_release(struct kref *kref);
+irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
+
+/* from remoteproc_rpmsg.c */
+int rproc_add_rpmsg_vdev(struct rproc *);
+void rproc_remove_rpmsg_vdev(struct rproc *rproc);
+
+/* from remoteproc_debugfs.c */
+void rproc_remove_trace_file(struct dentry *tfile);
+struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
+					struct rproc_mem_entry *trace);
+void rproc_delete_debug_dir(struct rproc *rproc);
+void rproc_create_debug_dir(struct rproc *rproc);
+void rproc_init_debugfs(void);
+void rproc_exit_debugfs(void);
+
+#endif /* REMOTEPROC_INTERNAL_H */

drivers/remoteproc/remoteproc_rpmsg.c

+/*
+ * Remote processor messaging transport (OMAP platform-specific bits)
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Ohad Ben-Cohen <ohad@wizery.com>
+ * Brian Swetland <swetland@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/export.h>
+#include <linux/remoteproc.h>
+#include <linux/rpmsg.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_ring.h>
+#include <linux/err.h>
+#include <linux/kref.h>
+#include <linux/slab.h>
+
+#include "remoteproc_internal.h"
+
+/**
+ * struct rproc_virtio_vq_info - virtqueue state
+ * @vq_id: a unique index of this virtqueue (unique for this @rproc)
+ * @rproc: handle to the remote processor
+ *
+ * Such a struct will be maintained for every virtqueue we're
+ * using to communicate with the remote processor
+ */
+struct rproc_virtio_vq_info {
+	__u16 vq_id;
+	struct rproc *rproc;
+};
+
+/* kick the remote processor, and let it know which virtqueue to poke at */
+static void rproc_virtio_notify(struct virtqueue *vq)
+{
+	struct rproc_virtio_vq_info *rpvq = vq->priv;
+	struct rproc *rproc = rpvq->rproc;
+
+	dev_dbg(rproc->dev, "kicking vq id: %d\n", rpvq->vq_id);
+
+	rproc->ops->kick(rproc, rpvq->vq_id);
+}
+
+/**
+ * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
+ * @rproc: handle to the remote processor
+ * @vq_id: index of the signalled virtqueue
+ *
+ * This function should be called by the platform-specific rproc driver,
+ * when the remote processor signals that a specific virtqueue has pending
+ * messages available.
+ *
+ * Returns IRQ_NONE if no message was found in the @vq_id virtqueue,
+ * and otherwise returns IRQ_HANDLED.
+ */
+irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id)
+{
+	return vring_interrupt(0, rproc->rvdev->vq[vq_id]);
+}
+EXPORT_SYMBOL(rproc_vq_interrupt);
+
+static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
+				    unsigned id,
+				    void (*callback)(struct virtqueue *vq),
+				    const char *name)
+{
+	struct rproc *rproc = vdev_to_rproc(vdev);
+	struct rproc_vdev *rvdev = rproc->rvdev;
+	struct rproc_virtio_vq_info *rpvq;
+	struct virtqueue *vq;
+	void *addr;
+	int ret, len;
+
+	rpvq = kmalloc(sizeof(*rpvq), GFP_KERNEL);
+	if (!rpvq)
+		return ERR_PTR(-ENOMEM);
+
+	rpvq->rproc = rproc;
+	rpvq->vq_id = id;
+
+	addr = rvdev->vring[id].va;
+	len = rvdev->vring[id].len;
+
+	dev_dbg(rproc->dev, "vring%d: va %p qsz %d\n", id, addr, len);
+
+	/*
+	 * Create the new vq, and tell virtio we're not interested in
+	 * the 'weak' smp barriers, since we're talking with a real device.
+	 */
+	vq = vring_new_virtqueue(len, AMP_VRING_ALIGN, vdev, false, addr,
+					rproc_virtio_notify, callback, name);
+	if (!vq) {
+		dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name);
+		ret = -ENOMEM;
+		goto free_rpvq;
+	}
+
+	rvdev->vq[id] = vq;
+	vq->priv = rpvq;
+
+	return vq;
+
+free_rpvq:
+	kfree(rpvq);
+	return ERR_PTR(ret);
+}
+
+static void rproc_virtio_del_vqs(struct virtio_device *vdev)
+{
+	struct virtqueue *vq, *n;
+	struct rproc *rproc = vdev_to_rproc(vdev);
+
+	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
+		struct rproc_virtio_vq_info *rpvq = vq->priv;
+		vring_del_virtqueue(vq);
+		kfree(rpvq);
+	}
+
+	/* power down the remote processor */
+	rproc_shutdown(rproc);
+}
+
+static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+		       struct virtqueue *vqs[],
+		       vq_callback_t *callbacks[],
+		       const char *names[])
+{
+	struct rproc *rproc = vdev_to_rproc(vdev);
+	int i, ret;
+
+	/* we maintain two virtqueues per remote processor (for RX and TX) */
+	if (nvqs != 2)
+		return -EINVAL;
+
+	/* boot the remote processor */
+	ret = rproc_boot(rproc);
+	if (ret) {
+		dev_err(rproc->dev, "rproc_boot() failed %d\n", ret);
+		goto error;
+	}
+
+	for (i = 0; i < nvqs; ++i) {
+		vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]);
+		if (IS_ERR(vqs[i])) {
+			ret = PTR_ERR(vqs[i]);
+			goto error;
+		}
+	}
+
+	return 0;
+
+error:
+	rproc_virtio_del_vqs(vdev);
+	return ret;
+}
+
+/*
+ * We don't support yet real virtio status semantics.
+ *
+ * The plan is to provide this via the VIRTIO HDR resource entry
+ * which is part of the firmware: this way the remote processor
+ * will be able to access the status values as set by us.
+ */
+static u8 rproc_virtio_get_status(struct virtio_device *vdev)
+{
+	return 0;
+}
+
+static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
+{
+	dev_dbg(&vdev->dev, "new status: %d\n", status);
+}
+
+static void rproc_virtio_reset(struct virtio_device *vdev)
+{
+	dev_dbg(&vdev->dev, "reset !\n");
+}
+
+/* provide the vdev features as retrieved from the firmware */
+static u32 rproc_virtio_get_features(struct virtio_device *vdev)
+{
+	struct rproc *rproc = vdev_to_rproc(vdev);
+
+	/* we only support a single vdev device for now */
+	return rproc->rvdev->dfeatures;
+}
+
+static void rproc_virtio_finalize_features(struct virtio_device *vdev)
+{
+	struct rproc *rproc = vdev_to_rproc(vdev);
+
+	/* Give virtio_ring a chance to accept features */
+	vring_transport_features(vdev);
+
+	/*
+	 * Remember the finalized features of our vdev, and provide it
+	 * to the remote processor once it is powered on.
+	 *
+	 * Similarly to the status field, we don't expose yet the negotiated
+	 * features to the remote processors at this point. This will be
+	 * fixed as part of a small resource table overhaul and then an
+	 * extension of the virtio resource entries.
+	 */
+	rproc->rvdev->gfeatures = vdev->features[0];
+}
+
+static struct virtio_config_ops rproc_virtio_config_ops = {
+	.get_features	= rproc_virtio_get_features,
+	.finalize_features = rproc_virtio_finalize_features,
+	.find_vqs	= rproc_virtio_find_vqs,
+	.del_vqs	= rproc_virtio_del_vqs,
+	.reset		= rproc_virtio_reset,
+	.set_status	= rproc_virtio_set_status,
+	.get_status	= rproc_virtio_get_status,
+};
+
+/*
+ * This function is called whenever vdev is released, and is responsible
+ * to decrement the remote processor's refcount taken when vdev was
+ * added.
+ *
+ * Never call this function directly; it will be called by the driver
+ * core when needed.
+ */
+static void rproc_vdev_release(struct device *dev)
+{
+	struct virtio_device *vdev = dev_to_virtio(dev);
+	struct rproc *rproc = vdev_to_rproc(vdev);
+
+	kref_put(&rproc->refcount, rproc_release);
+}
+
+/**
+ * rproc_add_rpmsg_vdev() - create an rpmsg virtio device
+ * @rproc: the rproc handle
+ *
+ * This function is called if virtio rpmsg support was found in the
+ * firmware of the remote processor.
+ *
+ * Today we only support creating a single rpmsg vdev (virtio device),
+ * but the plan is to remove this limitation. At that point this interface
+ * will be revised/extended.
+ */
+int rproc_add_rpmsg_vdev(struct rproc *rproc)
+{
+	struct device *dev = rproc->dev;
+	struct rproc_vdev *rvdev = rproc->rvdev;
+	int ret;
+
+	rvdev->vdev.id.device	= VIRTIO_ID_RPMSG,
+	rvdev->vdev.config	= &rproc_virtio_config_ops,
+	rvdev->vdev.dev.parent	= dev;
+	rvdev->vdev.dev.release	= rproc_vdev_release;
+
+	/*
+	 * We're indirectly making a non-temporary copy of the rproc pointer
+	 * here, because drivers probed with this vdev will indirectly
+	 * access the wrapping rproc.
+	 *
+	 * Therefore we must increment the rproc refcount here, and decrement
+	 * it _only_ when the vdev is released.
+	 */
+	kref_get(&rproc->refcount);
+
+	ret = register_virtio_device(&rvdev->vdev);
+	if (ret) {
+		kref_put(&rproc->refcount, rproc_release);
+		dev_err(dev, "failed to register vdev: %d\n", ret);
+	}
+
+	return ret;
+}
+
+/**
+ * rproc_remove_rpmsg_vdev() - remove an rpmsg vdev device
+ * @rproc: the rproc handle
+ *
+ * This function is called whenever @rproc is removed _iff_ an rpmsg
+ * vdev was created beforehand.
+ */
+void rproc_remove_rpmsg_vdev(struct rproc *rproc)
+{
+	struct rproc_vdev *rvdev = rproc->rvdev;
+
+	unregister_virtio_device(&rvdev->vdev);
+}

drivers/rpmsg/Kconfig

+menu "Rpmsg drivers (EXPERIMENTAL)"
+
+# RPMSG always gets selected by whoever wants it
+config RPMSG
+	tristate
+	select VIRTIO
+	select VIRTIO_RING
+	depends on EXPERIMENTAL
+
+endmenu

drivers/rpmsg/Makefile

+obj-$(CONFIG_RPMSG)	+= virtio_rpmsg_bus.o

include/linux/mod_devicetable.h

@@ -414,6 +414,15 @@ struct hv_vmbus_device_id {
 			__attribute__((aligned(sizeof(kernel_ulong_t))));
 };
 
+/* rpmsg */
+
+#define RPMSG_NAME_SIZE			32
+#define RPMSG_DEVICE_MODALIAS_FMT	"rpmsg:%s"
+
+struct rpmsg_device_id {
+	char name[RPMSG_NAME_SIZE];
+};
+
 /* i2c */
 
 #define I2C_NAME_SIZE	20

include/linux/remoteproc.h

+/*
+ * Remote Processor Framework
+ *
+ * Copyright(c) 2011 Texas Instruments, Inc.
+ * Copyright(c) 2011 Google, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in
+ *   the documentation and/or other materials provided with the
+ *   distribution.
+ * * Neither the name Texas Instruments nor the names of its
+ *   contributors may be used to endorse or promote products derived
+ *   from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef REMOTEPROC_H
+#define REMOTEPROC_H
+
+#include <linux/types.h>
+#include <linux/kref.h>
+#include <linux/klist.h>
+#include <linux/mutex.h>
+#include <linux/virtio.h>
+#include <linux/completion.h>
+
+/*
+ * The alignment between the consumer and producer parts of the vring.
+ * Note: this is part of the "wire" protocol. If you change this, you need
+ * to update your peers too.
+ */
+#define AMP_VRING_ALIGN	(4096)
+
+/**
+ * struct fw_resource - describes an entry from the resource section
+ * @type: resource type
+ * @id: index number of the resource
+ * @da: device address of the resource
+ * @pa: physical address of the resource
+ * @len: size, in bytes, of the resource
+ * @flags: properties of the resource, e.g. iommu protection required
+ * @reserved: must be 0 atm
+ * @name: name of resource
+ *
+ * The remote processor firmware should contain a "resource table":
+ * array of 'struct fw_resource' entries.
+ *
+ * Some resources entries are mere announcements, where the host is informed
+ * of specific remoteproc configuration. Other entries require the host to
+ * do something (e.g. reserve a requested resource) and possibly also reply
+ * by overwriting a member inside 'struct fw_resource' with info about the
+ * allocated resource.
+ *
+ * Different resource entries use different members of this struct,
+ * with different meanings. This is pretty limiting and error-prone,
+ * so the plan is to move to variable-length TLV-based resource entries,
+ * where each resource type will have its own structure.
+ */
+struct fw_resource {
+	u32 type;
+	u32 id;
+	u64 da;
+	u64 pa;
+	u32 len;
+	u32 flags;
+	u8 reserved[16];
+	u8 name[48];
+} __packed;
+
+/**
+ * enum fw_resource_type - types of resource entries
+ *
+ * @RSC_CARVEOUT:   request for allocation of a physically contiguous
+ *		    memory region.
+ * @RSC_DEVMEM:     request to iommu_map a memory-based peripheral.
+ * @RSC_TRACE:	    announces the availability of a trace buffer into which
+ *		    the remote processor will be writing logs. In this case,
+ *		    'da' indicates the device address where logs are written to,
+ *		    and 'len' is the size of the trace buffer.
+ * @RSC_VRING:	    request for allocation of a virtio vring (address should
+ *		    be indicated in 'da', and 'len' should contain the number
+ *		    of buffers supported by the vring).
+ * @RSC_VIRTIO_DEV: this entry declares about support for a virtio device,
+ *		    and serves as the virtio header. 'da' holds the
+ *		    the virtio device features, 'pa' holds the virtio guest
+ *		    features, 'len' holds the virtio status, and 'flags' holds
+ *		    the virtio id (currently only VIRTIO_ID_RPMSG is supported).
+ * @RSC_LAST:       just keep this one at the end
+ *
+ * Most of the resource entries share the basic idea of address/length
+ * negotiation with the host: the firmware usually asks (on behalf of the
+ * remote processor that will soon be booted with it) for memory
+ * of size 'len' bytes, and the host needs to allocate it and provide
+ * the device/physical address (when relevant) in 'da'/'pa' respectively.
+ *
+ * If the firmware is compiled with hard coded device addresses, and
+ * can't handle dynamically allocated 'da' values, then the 'da' field
+ * will contain the expected device addresses (today we actually only support
+ * this scheme, as there aren't yet any use cases for dynamically allocated
+ * device addresses).
+ *
+ * Please note that these values are used as indices to the rproc_handle_rsc
+ * lookup table, so please keep them sane. Moreover, @RSC_LAST is used to
+ * check the validity of an index before the lookup table is accessed, so
+ * please update it as needed.
+ */
+enum fw_resource_type {
+	RSC_CARVEOUT	= 0,
+	RSC_DEVMEM	= 1,
+	RSC_TRACE	= 2,
+	RSC_VRING	= 3,
+	RSC_VIRTIO_DEV	= 4,
+	RSC_LAST	= 5,
+};
+
+/**
+ * struct rproc_mem_entry - memory entry descriptor
+ * @va:	virtual address
+ * @dma: dma address
+ * @len: length, in bytes
+ * @da: device address
+ * @priv: associated data
+ * @node: list node
+ */
+struct rproc_mem_entry {
+	void *va;
+	dma_addr_t dma;
+	int len;
+	u64 da;
+	void *priv;
+	struct list_head node;
+};
+
+struct rproc;
+
+/**
+ * struct rproc_ops - platform-specific device handlers
+ * @start:	power on the device and boot it
+ * @stop:	power off the device
+ * @kick:	kick a virtqueue (virtqueue id given as a parameter)
+ */
+struct rproc_ops {
+	int (*start)(struct rproc *rproc);
+	int (*stop)(struct rproc *rproc);
+	void (*kick)(struct rproc *rproc, int vqid);
+};
+
+/**
+ * enum rproc_state - remote processor states
+ * @RPROC_OFFLINE:	device is powered off
+ * @RPROC_SUSPENDED:	device is suspended; needs to be woken up to receive
+ *			a message.
+ * @RPROC_RUNNING:	device is up and running
+ * @RPROC_CRASHED:	device has crashed; need to start recovery
+ * @RPROC_LAST:		just keep this one at the end
+ *
+ * Please note that the values of these states are used as indices
+ * to rproc_state_string, a state-to-name lookup table,
+ * so please keep the two synchronized. @RPROC_LAST is used to check
+ * the validity of an index before the lookup table is accessed, so
+ * please update it as needed too.
+ */
+enum rproc_state {
+	RPROC_OFFLINE	= 0,
+	RPROC_SUSPENDED	= 1,
+	RPROC_RUNNING	= 2,
+	RPROC_CRASHED	= 3,
+	RPROC_LAST	= 4,
+};
+
+/**
+ * struct rproc - represents a physical remote processor device
+ * @node: klist node of this rproc object
+ * @domain: iommu domain
+ * @name: human readable name of the rproc
+ * @firmware: name of firmware file to be loaded
+ * @priv: private data which belongs to the platform-specific rproc module
+ * @ops: platform-specific start/stop rproc handlers
+ * @dev: underlying device
+ * @refcount: refcount of users that have a valid pointer to this rproc
+ * @power: refcount of users who need this rproc powered up
+ * @state: state of the device
+ * @lock: lock which protects concurrent manipulations of the rproc
+ * @dbg_dir: debugfs directory of this rproc device
+ * @traces: list of trace buffers
+ * @num_traces: number of trace buffers
+ * @carveouts: list of physically contiguous memory allocations
+ * @mappings: list of iommu mappings we initiated, needed on shutdown
+ * @firmware_loading_complete: marks e/o asynchronous firmware loading
+ * @bootaddr: address of first instruction to boot rproc with (optional)
+ * @rvdev: virtio device (we only support a single rpmsg virtio device for now)
+ */
+struct rproc {
+	struct klist_node node;
+	struct iommu_domain *domain;
+	const char *name;
+	const char *firmware;
+	void *priv;
+	const struct rproc_ops *ops;
+	struct device *dev;
+	struct kref refcount;
+	atomic_t power;
+	unsigned int state;
+	struct mutex lock;
+	struct dentry *dbg_dir;
+	struct list_head traces;
+	int num_traces;
+	struct list_head carveouts;
+	struct list_head mappings;
+	struct completion firmware_loading_complete;
+	u64 bootaddr;
+	struct rproc_vdev *rvdev;
+};
+
+/**
+ * struct rproc_vdev - remoteproc state for a supported virtio device
+ * @rproc: the rproc handle
+ * @vdev: the virio device
+ * @vq: the virtqueues for this vdev
+ * @vring: the vrings for this vdev
+ * @dfeatures: virtio device features
+ * @gfeatures: virtio guest features
+ */
+struct rproc_vdev {
+	struct rproc *rproc;
+	struct virtio_device vdev;
+	struct virtqueue *vq[2];
+	struct rproc_mem_entry vring[2];
+	unsigned long dfeatures;
+	unsigned long gfeatures;
+};
+
+struct rproc *rproc_get_by_name(const char *name);
+void rproc_put(struct rproc *rproc);
+
+struct rproc *rproc_alloc(struct device *dev, const char *name,
+				const struct rproc_ops *ops,
+				const char *firmware, int len);
+void rproc_free(struct rproc *rproc);
+int rproc_register(struct rproc *rproc);
+int rproc_unregister(struct rproc *rproc);
+
+int rproc_boot(struct rproc *rproc);
+void rproc_shutdown(struct rproc *rproc);
+
+static inline struct rproc *vdev_to_rproc(struct virtio_device *vdev)
+{
+	struct rproc_vdev *rvdev = container_of(vdev, struct rproc_vdev, vdev);
+
+	return rvdev->rproc;
+}
+
+#endif /* REMOTEPROC_H */

include/linux/virtio_ids.h

@@ -34,6 +34,7 @@
 #define VIRTIO_ID_CONSOLE	3 /* virtio console */
 #define VIRTIO_ID_RNG		4 /* virtio ring */
 #define VIRTIO_ID_BALLOON	5 /* virtio balloon */
+#define VIRTIO_ID_RPMSG		7 /* virtio remote processor messaging */
 #define VIRTIO_ID_9P		9 /* 9p virtio console */
 
 #endif /* _LINUX_VIRTIO_IDS_H */

samples/Kconfig

@@ -61,4 +61,12 @@ config SAMPLE_KDB
 	  Build an example of how to dynamically add the hello
 	  command to the kdb shell.
 
+config SAMPLE_RPMSG_CLIENT
+	tristate "Build rpmsg client sample -- loadable modules only"
+	depends on RPMSG && m
+	help
+	  Build an rpmsg client sample driver, which demonstrates how
+	  to communicate with an AMP-configured remote processor over
+	  the rpmsg bus.
+
 endif # SAMPLES

samples/Makefile

 # Makefile for Linux samples code
 
 obj-$(CONFIG_SAMPLES)	+= kobject/ kprobes/ tracepoints/ trace_events/ \
-			   hw_breakpoint/ kfifo/ kdb/ hidraw/
+			   hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/

samples/rpmsg/Makefile

+obj-$(CONFIG_SAMPLE_RPMSG_CLIENT) += rpmsg_client_sample.o

samples/rpmsg/rpmsg_client_sample.c

+/*
+ * Remote processor messaging - sample client driver
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Ohad Ben-Cohen <ohad@wizery.com>
+ * Brian Swetland <swetland@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/rpmsg.h>
+
+#define MSG		"hello world!"
+#define MSG_LIMIT	100
+
+static void rpmsg_sample_cb(struct rpmsg_channel *rpdev, void *data, int len,
+						void *priv, u32 src)
+{
+	int ret;
+	static int rx_count;
+
+	dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n", ++rx_count, src);
+
+	print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1,
+		       data, len,  true);
+
+	/* samples should not live forever */
+	if (rx_count >= MSG_LIMIT) {
+		dev_info(&rpdev->dev, "goodbye!\n");
+		return;
+	}
+
+	/* send a new message now */
+	ret = rpmsg_send(rpdev, MSG, strlen(MSG));
+	if (ret)
+		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
+}
+
+static int rpmsg_sample_probe(struct rpmsg_channel *rpdev)
+{
+	int ret;
+
+	dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
+					rpdev->src, rpdev->dst);
+
+	/* send a message to our remote processor */
+	ret = rpmsg_send(rpdev, MSG, strlen(MSG));
+	if (ret) {
+		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __devexit rpmsg_sample_remove(struct rpmsg_channel *rpdev)
+{
+	dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
+}
+
+static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
+	{ .name	= "rpmsg-client-sample" },
+	{ },
+};
+MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
+
+static struct rpmsg_driver rpmsg_sample_client = {
+	.drv.name	= KBUILD_MODNAME,
+	.drv.owner	= THIS_MODULE,
+	.id_table	= rpmsg_driver_sample_id_table,
+	.probe		= rpmsg_sample_probe,
+	.callback	= rpmsg_sample_cb,
+	.remove		= __devexit_p(rpmsg_sample_remove),
+};
+
+static int __init rpmsg_client_sample_init(void)
+{
+	return register_rpmsg_driver(&rpmsg_sample_client);
+}
+module_init(rpmsg_client_sample_init);
+
+static void __exit rpmsg_client_sample_fini(void)
+{
+	unregister_rpmsg_driver(&rpmsg_sample_client);
+}
+module_exit(rpmsg_client_sample_fini);
+
+MODULE_DESCRIPTION("Remote processor messaging sample client driver");
+MODULE_LICENSE("GPL v2");