Merge tag 'rpmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull "remoteproc/rpmsg: new subsystem" from Arnd Bergmann:
 "This new subsystem provides a common way to talk to secondary
  processors on an SoC, e.g.  a DSP, GPU or service processor, using
  virtio as the transport.  In the long run, it should replace a few
  dozen vendor specific ways to do the same thing, which all never made
  it into the upstream kernel.  There is a broad agreement that rpmsg is
  the way to go here and several vendors have started working on
  replacing their own subsystems.

  Two branches each add one virtio protocol number.  Fortunately the
  numbers were agreed upon in advance, so there are only context
  changes.

  Signed-off-by: Arnd Bergmann <arnd@arndb.de>"

Fixed up trivial protocol number conflict due to the mentioned additions
next to each other.

* tag 'rpmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (32 commits)
  remoteproc: cleanup resource table parsing paths
  remoteproc: remove the hardcoded vring alignment
  remoteproc/omap: remove the mbox_callback limitation
  remoteproc: remove the single rpmsg vdev limitation
  remoteproc: safer boot/shutdown order
  remoteproc: remoteproc_rpmsg -> remoteproc_virtio
  remoteproc: resource table overhaul
  rpmsg: fix build warning when dma_addr_t is 64-bit
  rpmsg: fix published buffer length in rpmsg_recv_done
  rpmsg: validate incoming message length before propagating
  rpmsg: fix name service endpoint leak
  remoteproc/omap: two Kconfig fixes
  remoteproc: make sure we're parsing a 32bit firmware
  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
  ...

Conflicts:
	include/linux/virtio_ids.h

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

@@ -5634,6 +5634,13 @@ 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

@@ -130,6 +130,10 @@ 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

@@ -125,6 +125,8 @@ 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
+	depends on OMAP_IOMMU
+	select REMOTEPROC
+	select OMAP_MBOX_FWK
+	select RPMSG
+	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-$(CONFIG_REMOTEPROC)		+= remoteproc.o
+remoteproc-y				:= remoteproc_core.o
+remoteproc-y				+= remoteproc_debugfs.o
+remoteproc-y				+= remoteproc_virtio.o
+obj-$(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:
+		/* msg contains the index of the triggered vring */
+		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_virtio.c */
+int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id);
+void rproc_remove_virtio_dev(struct rproc_vdev *rvdev);
+
+/* 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_virtio.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/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"
+
+/* kick the remote processor, and let it know which virtqueue to poke at */
+static void rproc_virtio_notify(struct virtqueue *vq)
+{
+	struct rproc_vring *rvring = vq->priv;
+	struct rproc *rproc = rvring->rvdev->rproc;
+	int notifyid = rvring->notifyid;
+
+	dev_dbg(rproc->dev, "kicking vq index: %d\n", notifyid);
+
+	rproc->ops->kick(rproc, notifyid);
+}
+
+/**
+ * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
+ * @rproc: handle to the remote processor
+ * @notifyid: index of the signalled virtqueue (unique per this @rproc)
+ *
+ * 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 @notifyid virtqueue,
+ * and otherwise returns IRQ_HANDLED.
+ */
+irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
+{
+	struct rproc_vring *rvring;
+
+	dev_dbg(rproc->dev, "vq index %d is interrupted\n", notifyid);
+
+	rvring = idr_find(&rproc->notifyids, notifyid);
+	if (!rvring || !rvring->vq)
+		return IRQ_NONE;
+
+	return vring_interrupt(0, rvring->vq);
+}
+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_vdev *rvdev = vdev_to_rvdev(vdev);
+	struct rproc *rproc = vdev_to_rproc(vdev);
+	struct rproc_vring *rvring;
+	struct virtqueue *vq;
+	void *addr;
+	int len, size;
+
+	/* we're temporarily limited to two virtqueues per rvdev */
+	if (id >= ARRAY_SIZE(rvdev->vring))
+		return ERR_PTR(-EINVAL);
+
+	rvring = &rvdev->vring[id];
+
+	addr = rvring->va;
+	len = rvring->len;
+
+	/* zero vring */
+	size = vring_size(len, rvring->align);
+	memset(addr, 0, size);
+
+	dev_dbg(rproc->dev, "vring%d: va %p qsz %d notifyid %d\n",
+					id, addr, len, rvring->notifyid);
+
+	/*
+	 * 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, rvring->align, vdev, false, addr,
+					rproc_virtio_notify, callback, name);
+	if (!vq) {
+		dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	rvring->vq = vq;
+	vq->priv = rvring;
+
+	return vq;
+}
+
+static void rproc_virtio_del_vqs(struct virtio_device *vdev)
+{
+	struct virtqueue *vq, *n;
+	struct rproc *rproc = vdev_to_rproc(vdev);
+	struct rproc_vring *rvring;
+
+	/* power down the remote processor before deleting vqs */
+	rproc_shutdown(rproc);
+
+	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
+		rvring = vq->priv;
+		rvring->vq = NULL;
+		vring_del_virtqueue(vq);
+	}
+}
+
+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;
+
+	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;
+		}
+	}
+
+	/* now that the vqs are all set, boot the remote processor */
+	ret = rproc_boot(rproc);
+	if (ret) {
+		dev_err(rproc->dev, "rproc_boot() failed %d\n", ret);
+		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 VDEV 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, "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_vdev *rvdev = vdev_to_rvdev(vdev);
+
+	return rvdev->dfeatures;
+}
+
+static void rproc_virtio_finalize_features(struct virtio_device *vdev)
+{
+	struct rproc_vdev *rvdev = vdev_to_rvdev(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.
+	 */
+	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_virtio_dev() - register an rproc-induced virtio device
+ * @rvdev: the remote vdev
+ *
+ * This function registers a virtio device. This vdev's partent is
+ * the rproc device.
+ *
+ * Returns 0 on success or an appropriate error value otherwise.
+ */
+int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
+{
+	struct rproc *rproc = rvdev->rproc;
+	struct device *dev = rproc->dev;
+	struct virtio_device *vdev = &rvdev->vdev;
+	int ret;
+
+	vdev->id.device	= id,
+	vdev->config = &rproc_virtio_config_ops,
+	vdev->dev.parent = dev;
+	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(vdev);
+	if (ret) {
+		kref_put(&rproc->refcount, rproc_release);
+		dev_err(dev, "failed to register vdev: %d\n", ret);
+		goto out;
+	}
+
+	dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);
+
+out:
+	return ret;
+}
+
+/**
+ * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
+ * @rvdev: the remote vdev
+ *
+ * This function unregisters an existing virtio device.
+ */
+void rproc_remove_virtio_dev(struct rproc_vdev *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/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_SCSI		8 /* virtio scsi */
 #define VIRTIO_ID_9P		9 /* 9p virtio console */
 

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");