Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 1800 insertions, 0 deletions

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
new file mode 100644
index 000000000..e48069db1
--- /dev/null
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -0,0 +1,1800 @@
+/*
+ * 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>
+ * Mark Grosen <mgrosen@ti.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/module.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/dma-mapping.h>
+#include <linux/firmware.h>
+#include <linux/string.h>
+#include <linux/debugfs.h>
+#include <linux/devcoredump.h>
+#include <linux/remoteproc.h>
+#include <linux/iommu.h>
+#include <linux/idr.h>
+#include <linux/elf.h>
+#include <linux/crc32.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_ring.h>
+#include <asm/byteorder.h>
+
+#include "remoteproc_internal.h"
+
+static DEFINE_MUTEX(rproc_list_mutex);
+static LIST_HEAD(rproc_list);
+
+typedef int (*rproc_handle_resources_t)(struct rproc *rproc,
+				struct resource_table *table, int len);
+typedef int (*rproc_handle_resource_t)(struct rproc *rproc,
+				 void *, int offset, int avail);
+
+/* Unique indices for remoteproc devices */
+static DEFINE_IDA(rproc_dev_index);
+
+static const char * const rproc_crash_names[] = {
+	[RPROC_MMUFAULT]	= "mmufault",
+	[RPROC_WATCHDOG]	= "watchdog",
+	[RPROC_FATAL_ERROR]	= "fatal error",
+};
+
+/* translate rproc_crash_type to string */
+static const char *rproc_crash_to_string(enum rproc_crash_type type)
+{
+	if (type < ARRAY_SIZE(rproc_crash_names))
+		return rproc_crash_names[type];
+	return "unknown";
+}
+
+/*
+ * This is the IOMMU fault handler we register with the IOMMU API
+ * (when relevant; not all remote processors access memory through
+ * an IOMMU).
+ *
+ * IOMMU core will invoke this handler whenever the remote processor
+ * will try to access an unmapped device address.
+ */
+static int rproc_iommu_fault(struct iommu_domain *domain, struct device *dev,
+			     unsigned long iova, int flags, void *token)
+{
+	struct rproc *rproc = token;
+
+	dev_err(dev, "iommu fault: da 0x%lx flags 0x%x\n", iova, flags);
+
+	rproc_report_crash(rproc, RPROC_MMUFAULT);
+
+	/*
+	 * Let the iommu core know we're not really handling this fault;
+	 * we just used it as a recovery trigger.
+	 */
+	return -ENOSYS;
+}
+
+static int rproc_enable_iommu(struct rproc *rproc)
+{
+	struct iommu_domain *domain;
+	struct device *dev = rproc->dev.parent;
+	int ret;
+
+	if (!rproc->has_iommu) {
+		dev_dbg(dev, "iommu not present\n");
+		return 0;
+	}
+
+	domain = iommu_domain_alloc(dev->bus);
+	if (!domain) {
+		dev_err(dev, "can't alloc iommu domain\n");
+		return -ENOMEM;
+	}
+
+	iommu_set_fault_handler(domain, rproc_iommu_fault, rproc);
+
+	ret = iommu_attach_device(domain, dev);
+	if (ret) {
+		dev_err(dev, "can't attach iommu device: %d\n", ret);
+		goto free_domain;
+	}
+
+	rproc->domain = domain;
+
+	return 0;
+
+free_domain:
+	iommu_domain_free(domain);
+	return ret;
+}
+
+static void rproc_disable_iommu(struct rproc *rproc)
+{
+	struct iommu_domain *domain = rproc->domain;
+	struct device *dev = rproc->dev.parent;
+
+	if (!domain)
+		return;
+
+	iommu_detach_device(domain, dev);
+	iommu_domain_free(domain);
+}
+
+/**
+ * rproc_da_to_va() - lookup the kernel virtual address for a remoteproc address
+ * @rproc: handle of a remote processor
+ * @da: remoteproc device address to translate
+ * @len: length of the memory region @da is pointing to
+ *
+ * Some remote processors will ask us to allocate them physically contiguous
+ * memory regions (which we call "carveouts"), and map them to specific
+ * device addresses (which are hardcoded in the firmware). They may also have
+ * dedicated memory regions internal to the processors, and use them either
+ * exclusively or alongside carveouts.
+ *
+ * They may then ask us to copy objects into specific device addresses (e.g.
+ * code/data sections) or expose us certain symbols in other device address
+ * (e.g. their trace buffer).
+ *
+ * This function is a helper function with which we can go over the allocated
+ * carveouts and translate specific device addresses to kernel virtual addresses
+ * so we can access the referenced memory. This function also allows to perform
+ * translations on the internal remoteproc memory regions through a platform
+ * implementation specific da_to_va ops, if present.
+ *
+ * The function returns a valid kernel address on success or NULL on failure.
+ *
+ * Note: phys_to_virt(iommu_iova_to_phys(rproc->domain, da)) will work too,
+ * but only on kernel direct mapped RAM memory. Instead, we're just using
+ * here the output of the DMA API for the carveouts, which should be more
+ * correct.
+ */
+void *rproc_da_to_va(struct rproc *rproc, u64 da, int len)
+{
+	struct rproc_mem_entry *carveout;
+	void *ptr = NULL;
+
+	if (rproc->ops->da_to_va) {
+		ptr = rproc->ops->da_to_va(rproc, da, len);
+		if (ptr)
+			goto out;
+	}
+
+	list_for_each_entry(carveout, &rproc->carveouts, node) {
+		int offset = da - carveout->da;
+
+		/* try next carveout if da is too small */
+		if (offset < 0)
+			continue;
+
+		/* try next carveout if da is too large */
+		if (offset + len > carveout->len)
+			continue;
+
+		ptr = carveout->va + offset;
+
+		break;
+	}
+
+out:
+	return ptr;
+}
+EXPORT_SYMBOL(rproc_da_to_va);
+
+int rproc_alloc_vring(struct rproc_vdev *rvdev, int i)
+{
+	struct rproc *rproc = rvdev->rproc;
+	struct device *dev = &rproc->dev;
+	struct rproc_vring *rvring = &rvdev->vring[i];
+	struct fw_rsc_vdev *rsc;
+	dma_addr_t dma;
+	void *va;
+	int ret, size, notifyid;
+
+	/* actual size of vring (in bytes) */
+	size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
+
+	/*
+	 * Allocate non-cacheable memory for the vring. In the future
+	 * this call will also configure the IOMMU for us
+	 */
+	va = dma_alloc_coherent(dev->parent, size, &dma, GFP_KERNEL);
+	if (!va) {
+		dev_err(dev->parent, "dma_alloc_coherent failed\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Assign an rproc-wide unique index for this vring
+	 * TODO: assign a notifyid for rvdev updates as well
+	 * TODO: support predefined notifyids (via resource table)
+	 */
+	ret = idr_alloc(&rproc->notifyids, rvring, 0, 0, GFP_KERNEL);
+	if (ret < 0) {
+		dev_err(dev, "idr_alloc failed: %d\n", ret);
+		dma_free_coherent(dev->parent, size, va, dma);
+		return ret;
+	}
+	notifyid = ret;
+
+	/* Potentially bump max_notifyid */
+	if (notifyid > rproc->max_notifyid)
+		rproc->max_notifyid = notifyid;
+
+	dev_dbg(dev, "vring%d: va %pK dma %pad size 0x%x idr %d\n",
+		i, va, &dma, size, notifyid);
+
+	rvring->va = va;
+	rvring->dma = dma;
+	rvring->notifyid = notifyid;
+
+	/*
+	 * Let the rproc know the notifyid and da of this vring.
+	 * Not all platforms use dma_alloc_coherent to automatically
+	 * set up the iommu. In this case the device address (da) will
+	 * hold the physical address and not the device address.
+	 */
+	rsc = (void *)rproc->table_ptr + rvdev->rsc_offset;
+	rsc->vring[i].da = dma;
+	rsc->vring[i].notifyid = notifyid;
+	return 0;
+}
+
+static int
+rproc_parse_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i)
+{
+	struct rproc *rproc = rvdev->rproc;
+	struct device *dev = &rproc->dev;
+	struct fw_rsc_vdev_vring *vring = &rsc->vring[i];
+	struct rproc_vring *rvring = &rvdev->vring[i];
+
+	dev_dbg(dev, "vdev rsc: vring%d: da 0x%x, qsz %d, align %d\n",
+		i, vring->da, vring->num, vring->align);
+
+	/* verify queue size and vring alignment are sane */
+	if (!vring->num || !vring->align) {
+		dev_err(dev, "invalid qsz (%d) or alignment (%d)\n",
+			vring->num, vring->align);
+		return -EINVAL;
+	}
+
+	rvring->len = vring->num;
+	rvring->align = vring->align;
+	rvring->rvdev = rvdev;
+
+	return 0;
+}
+
+void rproc_free_vring(struct rproc_vring *rvring)
+{
+	int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align));
+	struct rproc *rproc = rvring->rvdev->rproc;
+	int idx = rvring - rvring->rvdev->vring;
+	struct fw_rsc_vdev *rsc;
+
+	dma_free_coherent(rproc->dev.parent, size, rvring->va, rvring->dma);
+	idr_remove(&rproc->notifyids, rvring->notifyid);
+
+	/* reset resource entry info */
+	rsc = (void *)rproc->table_ptr + rvring->rvdev->rsc_offset;
+	rsc->vring[idx].da = 0;
+	rsc->vring[idx].notifyid = -1;
+}
+
+static int rproc_vdev_do_start(struct rproc_subdev *subdev)
+{
+	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
+
+	return rproc_add_virtio_dev(rvdev, rvdev->id);
+}
+
+static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
+{
+	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
+
+	rproc_remove_virtio_dev(rvdev);
+}
+
+/**
+ * rproc_handle_vdev() - handle a vdev fw resource
+ * @rproc: the remote processor
+ * @rsc: the vring resource descriptor
+ * @avail: size of available data (for sanity checking the image)
+ *
+ * This resource entry requests the host to statically register a virtio
+ * device (vdev), and setup everything needed to support it. It contains
+ * everything needed to make it possible: the virtio device id, virtio
+ * device features, vrings information, virtio config space, etc...
+ *
+ * Before registering the vdev, the vrings are allocated from non-cacheable
+ * physically contiguous memory. Currently we only support two vrings per
+ * remote processor (temporary limitation). We might also want to consider
+ * doing the vring allocation only later when ->find_vqs() is invoked, and
+ * then release them upon ->del_vqs().
+ *
+ * Note: @da is currently not really handled correctly: we dynamically
+ * allocate it using the DMA API, ignoring requested hard coded addresses,
+ * and we don't take care of any required IOMMU programming. This is all
+ * going to be taken care of when the generic iommu-based DMA API will be
+ * merged. Meanwhile, statically-addressed iommu-based firmware images should
+ * use RSC_DEVMEM resource entries to map their required @da to the physical
+ * address of their base CMA region (ouch, hacky!).
+ *
+ * Returns 0 on success, or an appropriate error code otherwise
+ */
+static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
+			     int offset, int avail)
+{
+	struct device *dev = &rproc->dev;
+	struct rproc_vdev *rvdev;
+	int i, ret;
+
+	/* make sure resource isn't truncated */
+	if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring)
+			+ rsc->config_len > avail) {
+		dev_err(dev, "vdev rsc is truncated\n");
+		return -EINVAL;
+	}
+
+	/* make sure reserved bytes are zeroes */
+	if (rsc->reserved[0] || rsc->reserved[1]) {
+		dev_err(dev, "vdev rsc has non zero reserved bytes\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "vdev rsc: id %d, dfeatures 0x%x, cfg len %d, %d vrings\n",
+		rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings);
+
+	/* we currently support only two vrings per rvdev */
+	if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) {
+		dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings);
+		return -EINVAL;
+	}
+
+	rvdev = kzalloc(sizeof(*rvdev), GFP_KERNEL);
+	if (!rvdev)
+		return -ENOMEM;
+
+	kref_init(&rvdev->refcount);
+
+	rvdev->id = rsc->id;
+	rvdev->rproc = rproc;
+
+	/* parse the vrings */
+	for (i = 0; i < rsc->num_of_vrings; i++) {
+		ret = rproc_parse_vring(rvdev, rsc, i);
+		if (ret)
+			goto free_rvdev;
+	}
+
+	/* remember the resource offset*/
+	rvdev->rsc_offset = offset;
+
+	/* allocate the vring resources */
+	for (i = 0; i < rsc->num_of_vrings; i++) {
+		ret = rproc_alloc_vring(rvdev, i);
+		if (ret)
+			goto unwind_vring_allocations;
+	}
+
+	list_add_tail(&rvdev->node, &rproc->rvdevs);
+
+	rvdev->subdev.start = rproc_vdev_do_start;
+	rvdev->subdev.stop = rproc_vdev_do_stop;
+
+	rproc_add_subdev(rproc, &rvdev->subdev);
+
+	return 0;
+
+unwind_vring_allocations:
+	for (i--; i >= 0; i--)
+		rproc_free_vring(&rvdev->vring[i]);
+free_rvdev:
+	kfree(rvdev);
+	return ret;
+}
+
+void rproc_vdev_release(struct kref *ref)
+{
+	struct rproc_vdev *rvdev = container_of(ref, struct rproc_vdev, refcount);
+	struct rproc_vring *rvring;
+	struct rproc *rproc = rvdev->rproc;
+	int id;
+
+	for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
+		rvring = &rvdev->vring[id];
+		if (!rvring->va)
+			continue;
+
+		rproc_free_vring(rvring);
+	}
+
+	rproc_remove_subdev(rproc, &rvdev->subdev);
+	list_del(&rvdev->node);
+	kfree(rvdev);
+}
+
+/**
+ * rproc_handle_trace() - handle a shared trace buffer resource
+ * @rproc: the remote processor
+ * @rsc: the trace resource descriptor
+ * @avail: size of available data (for sanity checking the image)
+ *
+ * In case the remote processor dumps trace logs into memory,
+ * export it via debugfs.
+ *
+ * Currently, the 'da' member of @rsc should contain the device address
+ * where the remote processor is dumping the traces. Later we could also
+ * support dynamically allocating this address using the generic
+ * DMA API (but currently there isn't a use case for that).
+ *
+ * Returns 0 on success, or an appropriate error code otherwise
+ */
+static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc,
+			      int offset, int avail)
+{
+	struct rproc_mem_entry *trace;
+	struct device *dev = &rproc->dev;
+	void *ptr;
+	char name[15];
+
+	if (sizeof(*rsc) > avail) {
+		dev_err(dev, "trace rsc is truncated\n");
+		return -EINVAL;
+	}
+
+	/* make sure reserved bytes are zeroes */
+	if (rsc->reserved) {
+		dev_err(dev, "trace rsc has non zero reserved bytes\n");
+		return -EINVAL;
+	}
+
+	/* what's the kernel address of this resource ? */
+	ptr = rproc_da_to_va(rproc, rsc->da, rsc->len);
+	if (!ptr) {
+		dev_err(dev, "erroneous trace resource entry\n");
+		return -EINVAL;
+	}
+
+	trace = kzalloc(sizeof(*trace), GFP_KERNEL);
+	if (!trace)
+		return -ENOMEM;
+
+	/* set the trace buffer dma properties */
+	trace->len = rsc->len;
+	trace->va = ptr;
+
+	/* make sure snprintf always null terminates, even if truncating */
+	snprintf(name, sizeof(name), "trace%d", rproc->num_traces);
+
+	/* create the debugfs entry */
+	trace->priv = rproc_create_trace_file(name, rproc, trace);
+	if (!trace->priv) {
+		trace->va = NULL;
+		kfree(trace);
+		return -EINVAL;
+	}
+
+	list_add_tail(&trace->node, &rproc->traces);
+
+	rproc->num_traces++;
+
+	dev_dbg(dev, "%s added: va %pK, da 0x%x, len 0x%x\n",
+		name, ptr, rsc->da, rsc->len);
+
+	return 0;
+}
+
+/**
+ * rproc_handle_devmem() - handle devmem resource entry
+ * @rproc: remote processor handle
+ * @rsc: the devmem resource entry
+ * @avail: size of available data (for sanity checking the image)
+ *
+ * Remote processors commonly need to access certain on-chip peripherals.
+ *
+ * Some of these remote processors access memory via an iommu device,
+ * and might require us to configure their iommu before they can access
+ * the on-chip peripherals they need.
+ *
+ * This resource entry is a request to map such a peripheral device.
+ *
+ * These devmem entries will contain the physical address of the device in
+ * the 'pa' member. If a specific device address is expected, then 'da' will
+ * contain it (currently this is the only use case supported). 'len' will
+ * contain the size of the physical region we need to map.
+ *
+ * Currently we just "trust" those devmem entries to contain valid physical
+ * addresses, but this is going to change: we want the implementations to
+ * tell us ranges of physical addresses the firmware is allowed to request,
+ * and not allow firmwares to request access to physical addresses that
+ * are outside those ranges.
+ */
+static int rproc_handle_devmem(struct rproc *rproc, struct fw_rsc_devmem *rsc,
+			       int offset, int avail)
+{
+	struct rproc_mem_entry *mapping;
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	/* no point in handling this resource without a valid iommu domain */
+	if (!rproc->domain)
+		return -EINVAL;
+
+	if (sizeof(*rsc) > avail) {
+		dev_err(dev, "devmem rsc is truncated\n");
+		return -EINVAL;
+	}
+
+	/* make sure reserved bytes are zeroes */
+	if (rsc->reserved) {
+		dev_err(dev, "devmem rsc has non zero reserved bytes\n");
+		return -EINVAL;
+	}
+
+	mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
+	if (!mapping)
+		return -ENOMEM;
+
+	ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len, rsc->flags);
+	if (ret) {
+		dev_err(dev, "failed to map devmem: %d\n", ret);
+		goto out;
+	}
+
+	/*
+	 * We'll need this info later when we'll want to unmap everything
+	 * (e.g. on shutdown).
+	 *
+	 * We can't trust the remote processor not to change the resource
+	 * table, so we must maintain this info independently.
+	 */
+	mapping->da = rsc->da;
+	mapping->len = rsc->len;
+	list_add_tail(&mapping->node, &rproc->mappings);
+
+	dev_dbg(dev, "mapped devmem pa 0x%x, da 0x%x, len 0x%x\n",
+		rsc->pa, rsc->da, rsc->len);
+
+	return 0;
+
+out:
+	kfree(mapping);
+	return ret;
+}
+
+/**
+ * rproc_handle_carveout() - handle phys contig memory allocation requests
+ * @rproc: rproc handle
+ * @rsc: the resource entry
+ * @avail: size of available data (for image validation)
+ *
+ * This function will handle firmware requests for allocation of physically
+ * contiguous memory regions.
+ *
+ * These request entries should come first in the firmware's resource table,
+ * as other firmware entries might request placing other data objects inside
+ * these memory regions (e.g. data/code segments, trace resource entries, ...).
+ *
+ * Allocating memory this way helps utilizing the reserved physical memory
+ * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries
+ * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB
+ * pressure is important; it may have a substantial impact on performance.
+ */
+static int rproc_handle_carveout(struct rproc *rproc,
+				 struct fw_rsc_carveout *rsc,
+				 int offset, int avail)
+{
+	struct rproc_mem_entry *carveout, *mapping;
+	struct device *dev = &rproc->dev;
+	dma_addr_t dma;
+	void *va;
+	int ret;
+
+	if (sizeof(*rsc) > avail) {
+		dev_err(dev, "carveout rsc is truncated\n");
+		return -EINVAL;
+	}
+
+	/* make sure reserved bytes are zeroes */
+	if (rsc->reserved) {
+		dev_err(dev, "carveout rsc has non zero reserved bytes\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "carveout rsc: name: %s, da 0x%x, pa 0x%x, len 0x%x, flags 0x%x\n",
+		rsc->name, rsc->da, rsc->pa, rsc->len, rsc->flags);
+
+	carveout = kzalloc(sizeof(*carveout), GFP_KERNEL);
+	if (!carveout)
+		return -ENOMEM;
+
+	va = dma_alloc_coherent(dev->parent, rsc->len, &dma, GFP_KERNEL);
+	if (!va) {
+		dev_err(dev->parent,
+			"failed to allocate dma memory: len 0x%x\n", rsc->len);
+		ret = -ENOMEM;
+		goto free_carv;
+	}
+
+	dev_dbg(dev, "carveout va %pK, dma %pad, len 0x%x\n",
+		va, &dma, rsc->len);
+
+	/*
+	 * Ok, this is non-standard.
+	 *
+	 * Sometimes we can't rely on the generic iommu-based DMA API
+	 * to dynamically allocate the device address and then set the IOMMU
+	 * tables accordingly, because some remote processors might
+	 * _require_ us to use hard coded device addresses that their
+	 * firmware was compiled with.
+	 *
+	 * In this case, we must use the IOMMU API directly and map
+	 * the memory to the device address as expected by the remote
+	 * processor.
+	 *
+	 * Obviously such remote processor devices should not be configured
+	 * to use the iommu-based DMA API: we expect 'dma' to contain the
+	 * physical address in this case.
+	 */
+	if (rproc->domain) {
+		mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
+		if (!mapping) {
+			ret = -ENOMEM;
+			goto dma_free;
+		}
+
+		ret = iommu_map(rproc->domain, rsc->da, dma, rsc->len,
+				rsc->flags);
+		if (ret) {
+			dev_err(dev, "iommu_map failed: %d\n", ret);
+			goto free_mapping;
+		}
+
+		/*
+		 * We'll need this info later when we'll want to unmap
+		 * everything (e.g. on shutdown).
+		 *
+		 * We can't trust the remote processor not to change the
+		 * resource table, so we must maintain this info independently.
+		 */
+		mapping->da = rsc->da;
+		mapping->len = rsc->len;
+		list_add_tail(&mapping->node, &rproc->mappings);
+
+		dev_dbg(dev, "carveout mapped 0x%x to %pad\n",
+			rsc->da, &dma);
+	}
+
+	/*
+	 * Some remote processors might need to know the pa
+	 * even though they are behind an IOMMU. E.g., OMAP4's
+	 * remote M3 processor needs this so it can control
+	 * on-chip hardware accelerators that are not behind
+	 * the IOMMU, and therefor must know the pa.
+	 *
+	 * Generally we don't want to expose physical addresses
+	 * if we don't have to (remote processors are generally
+	 * _not_ trusted), so we might want to do this only for
+	 * remote processor that _must_ have this (e.g. OMAP4's
+	 * dual M3 subsystem).
+	 *
+	 * Non-IOMMU processors might also want to have this info.
+	 * In this case, the device address and the physical address
+	 * are the same.
+	 */
+	rsc->pa = dma;
+
+	carveout->va = va;
+	carveout->len = rsc->len;
+	carveout->dma = dma;
+	carveout->da = rsc->da;
+
+	list_add_tail(&carveout->node, &rproc->carveouts);
+
+	return 0;
+
+free_mapping:
+	kfree(mapping);
+dma_free:
+	dma_free_coherent(dev->parent, rsc->len, va, dma);
+free_carv:
+	kfree(carveout);
+	return ret;
+}
+
+/*
+ * A lookup table for resource handlers. The indices are defined in
+ * enum fw_resource_type.
+ */
+static rproc_handle_resource_t rproc_loading_handlers[RSC_LAST] = {
+	[RSC_CARVEOUT] = (rproc_handle_resource_t)rproc_handle_carveout,
+	[RSC_DEVMEM] = (rproc_handle_resource_t)rproc_handle_devmem,
+	[RSC_TRACE] = (rproc_handle_resource_t)rproc_handle_trace,
+	[RSC_VDEV] = (rproc_handle_resource_t)rproc_handle_vdev,
+};
+
+/* handle firmware resource entries before booting the remote processor */
+static int rproc_handle_resources(struct rproc *rproc,
+				  rproc_handle_resource_t handlers[RSC_LAST])
+{
+	struct device *dev = &rproc->dev;
+	rproc_handle_resource_t handler;
+	int ret = 0, i;
+
+	if (!rproc->table_ptr)
+		return 0;
+
+	for (i = 0; i < rproc->table_ptr->num; i++) {
+		int offset = rproc->table_ptr->offset[i];
+		struct fw_rsc_hdr *hdr = (void *)rproc->table_ptr + offset;
+		int avail = rproc->table_sz - offset - sizeof(*hdr);
+		void *rsc = (void *)hdr + sizeof(*hdr);
+
+		/* make sure table isn't truncated */
+		if (avail < 0) {
+			dev_err(dev, "rsc table is truncated\n");
+			return -EINVAL;
+		}
+
+		dev_dbg(dev, "rsc: type %d\n", hdr->type);
+
+		if (hdr->type >= RSC_LAST) {
+			dev_warn(dev, "unsupported resource %d\n", hdr->type);
+			continue;
+		}
+
+		handler = handlers[hdr->type];
+		if (!handler)
+			continue;
+
+		ret = handler(rproc, rsc, offset + sizeof(*hdr), avail);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static int rproc_prepare_subdevices(struct rproc *rproc)
+{
+	struct rproc_subdev *subdev;
+	int ret;
+
+	list_for_each_entry(subdev, &rproc->subdevs, node) {
+		if (subdev->prepare) {
+			ret = subdev->prepare(subdev);
+			if (ret)
+				goto unroll_preparation;
+		}
+	}
+
+	return 0;
+
+unroll_preparation:
+	list_for_each_entry_continue_reverse(subdev, &rproc->subdevs, node) {
+		if (subdev->unprepare)
+			subdev->unprepare(subdev);
+	}
+
+	return ret;
+}
+
+static int rproc_start_subdevices(struct rproc *rproc)
+{
+	struct rproc_subdev *subdev;
+	int ret;
+
+	list_for_each_entry(subdev, &rproc->subdevs, node) {
+		if (subdev->start) {
+			ret = subdev->start(subdev);
+			if (ret)
+				goto unroll_registration;
+		}
+	}
+
+	return 0;
+
+unroll_registration:
+	list_for_each_entry_continue_reverse(subdev, &rproc->subdevs, node) {
+		if (subdev->stop)
+			subdev->stop(subdev, true);
+	}
+
+	return ret;
+}
+
+static void rproc_stop_subdevices(struct rproc *rproc, bool crashed)
+{
+	struct rproc_subdev *subdev;
+
+	list_for_each_entry_reverse(subdev, &rproc->subdevs, node) {
+		if (subdev->stop)
+			subdev->stop(subdev, crashed);
+	}
+}
+
+static void rproc_unprepare_subdevices(struct rproc *rproc)
+{
+	struct rproc_subdev *subdev;
+
+	list_for_each_entry_reverse(subdev, &rproc->subdevs, node) {
+		if (subdev->unprepare)
+			subdev->unprepare(subdev);
+	}
+}
+
+/**
+ * rproc_coredump_cleanup() - clean up dump_segments list
+ * @rproc: the remote processor handle
+ */
+static void rproc_coredump_cleanup(struct rproc *rproc)
+{
+	struct rproc_dump_segment *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
+		list_del(&entry->node);
+		kfree(entry);
+	}
+}
+
+/**
+ * rproc_resource_cleanup() - clean up and free all acquired resources
+ * @rproc: rproc handle
+ *
+ * This function will free all resources acquired for @rproc, and it
+ * is called whenever @rproc either shuts down or fails to boot.
+ */
+static void rproc_resource_cleanup(struct rproc *rproc)
+{
+	struct rproc_mem_entry *entry, *tmp;
+	struct rproc_vdev *rvdev, *rvtmp;
+	struct device *dev = &rproc->dev;
+
+	/* clean up debugfs trace entries */
+	list_for_each_entry_safe(entry, tmp, &rproc->traces, node) {
+		rproc_remove_trace_file(entry->priv);
+		rproc->num_traces--;
+		list_del(&entry->node);
+		kfree(entry);
+	}
+
+	/* clean up iommu mapping entries */
+	list_for_each_entry_safe(entry, tmp, &rproc->mappings, node) {
+		size_t unmapped;
+
+		unmapped = iommu_unmap(rproc->domain, entry->da, entry->len);
+		if (unmapped != entry->len) {
+			/* nothing much to do besides complaining */
+			dev_err(dev, "failed to unmap %u/%zu\n", entry->len,
+				unmapped);
+		}
+
+		list_del(&entry->node);
+		kfree(entry);
+	}
+
+	/* clean up carveout allocations */
+	list_for_each_entry_safe(entry, tmp, &rproc->carveouts, node) {
+		dma_free_coherent(dev->parent, entry->len, entry->va,
+				  entry->dma);
+		list_del(&entry->node);
+		kfree(entry);
+	}
+
+	/* clean up remote vdev entries */
+	list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
+		kref_put(&rvdev->refcount, rproc_vdev_release);
+
+	rproc_coredump_cleanup(rproc);
+}
+
+static int rproc_start(struct rproc *rproc, const struct firmware *fw)
+{
+	struct resource_table *loaded_table;
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	/* load the ELF segments to memory */
+	ret = rproc_load_segments(rproc, fw);
+	if (ret) {
+		dev_err(dev, "Failed to load program segments: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * The starting device has been given the rproc->cached_table as the
+	 * resource table. The address of the vring along with the other
+	 * allocated resources (carveouts etc) is stored in cached_table.
+	 * In order to pass this information to the remote device we must copy
+	 * this information to device memory. We also update the table_ptr so
+	 * that any subsequent changes will be applied to the loaded version.
+	 */
+	loaded_table = rproc_find_loaded_rsc_table(rproc, fw);
+	if (loaded_table) {
+		memcpy(loaded_table, rproc->cached_table, rproc->table_sz);
+		rproc->table_ptr = loaded_table;
+	}
+
+	ret = rproc_prepare_subdevices(rproc);
+	if (ret) {
+		dev_err(dev, "failed to prepare subdevices for %s: %d\n",
+			rproc->name, ret);
+		goto reset_table_ptr;
+	}
+
+	/* power up the remote processor */
+	ret = rproc->ops->start(rproc);
+	if (ret) {
+		dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret);
+		goto unprepare_subdevices;
+	}
+
+	/* Start any subdevices for the remote processor */
+	ret = rproc_start_subdevices(rproc);
+	if (ret) {
+		dev_err(dev, "failed to probe subdevices for %s: %d\n",
+			rproc->name, ret);
+		goto stop_rproc;
+	}
+
+	rproc->state = RPROC_RUNNING;
+
+	dev_info(dev, "remote processor %s is now up\n", rproc->name);
+
+	return 0;
+
+stop_rproc:
+	rproc->ops->stop(rproc);
+unprepare_subdevices:
+	rproc_unprepare_subdevices(rproc);
+reset_table_ptr:
+	rproc->table_ptr = rproc->cached_table;
+
+	return ret;
+}
+
+/*
+ * take a firmware and boot a remote processor with it.
+ */
+static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
+{
+	struct device *dev = &rproc->dev;
+	const char *name = rproc->firmware;
+	int ret;
+
+	ret = rproc_fw_sanity_check(rproc, fw);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
+
+	/*
+	 * if enabling an IOMMU isn't relevant for this rproc, this is
+	 * just a nop
+	 */
+	ret = rproc_enable_iommu(rproc);
+	if (ret) {
+		dev_err(dev, "can't enable iommu: %d\n", ret);
+		return ret;
+	}
+
+	rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
+
+	/* Load resource table, core dump segment list etc from the firmware */
+	ret = rproc_parse_fw(rproc, fw);
+	if (ret)
+		goto disable_iommu;
+
+	/* reset max_notifyid */
+	rproc->max_notifyid = -1;
+
+	/* handle fw resources which are required to boot rproc */
+	ret = rproc_handle_resources(rproc, rproc_loading_handlers);
+	if (ret) {
+		dev_err(dev, "Failed to process resources: %d\n", ret);
+		goto clean_up_resources;
+	}
+
+	ret = rproc_start(rproc, fw);
+	if (ret)
+		goto clean_up_resources;
+
+	return 0;
+
+clean_up_resources:
+	rproc_resource_cleanup(rproc);
+	kfree(rproc->cached_table);
+	rproc->cached_table = NULL;
+	rproc->table_ptr = NULL;
+disable_iommu:
+	rproc_disable_iommu(rproc);
+	return ret;
+}
+
+/*
+ * take a firmware and boot it up.
+ *
+ * Note: this function is called asynchronously upon registration of the
+ * remote processor (so we must wait until it completes before we try
+ * to unregister the device. one other option is just to use kref here,
+ * that might be cleaner).
+ */
+static void rproc_auto_boot_callback(const struct firmware *fw, void *context)
+{
+	struct rproc *rproc = context;
+
+	rproc_boot(rproc);
+
+	release_firmware(fw);
+}
+
+static int rproc_trigger_auto_boot(struct rproc *rproc)
+{
+	int ret;
+
+	/*
+	 * We're initiating an asynchronous firmware loading, so we can
+	 * be built-in kernel code, without hanging the boot process.
+	 */
+	ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG,
+				      rproc->firmware, &rproc->dev, GFP_KERNEL,
+				      rproc, rproc_auto_boot_callback);
+	if (ret < 0)
+		dev_err(&rproc->dev, "request_firmware_nowait err: %d\n", ret);
+
+	return ret;
+}
+
+static int rproc_stop(struct rproc *rproc, bool crashed)
+{
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	/* Stop any subdevices for the remote processor */
+	rproc_stop_subdevices(rproc, crashed);
+
+	/* the installed resource table is no longer accessible */
+	rproc->table_ptr = rproc->cached_table;
+
+	/* power off the remote processor */
+	ret = rproc->ops->stop(rproc);
+	if (ret) {
+		dev_err(dev, "can't stop rproc: %d\n", ret);
+		return ret;
+	}
+
+	rproc_unprepare_subdevices(rproc);
+
+	rproc->state = RPROC_OFFLINE;
+
+	dev_info(dev, "stopped remote processor %s\n", rproc->name);
+
+	return 0;
+}
+
+/**
+ * rproc_coredump_add_segment() - add segment of device memory to coredump
+ * @rproc:	handle of a remote processor
+ * @da:		device address
+ * @size:	size of segment
+ *
+ * Add device memory to the list of segments to be included in a coredump for
+ * the remoteproc.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size)
+{
+	struct rproc_dump_segment *segment;
+
+	segment = kzalloc(sizeof(*segment), GFP_KERNEL);
+	if (!segment)
+		return -ENOMEM;
+
+	segment->da = da;
+	segment->size = size;
+
+	list_add_tail(&segment->node, &rproc->dump_segments);
+
+	return 0;
+}
+EXPORT_SYMBOL(rproc_coredump_add_segment);
+
+/**
+ * rproc_coredump() - perform coredump
+ * @rproc:	rproc handle
+ *
+ * This function will generate an ELF header for the registered segments
+ * and create a devcoredump device associated with rproc.
+ */
+static void rproc_coredump(struct rproc *rproc)
+{
+	struct rproc_dump_segment *segment;
+	struct elf32_phdr *phdr;
+	struct elf32_hdr *ehdr;
+	size_t data_size;
+	size_t offset;
+	void *data;
+	void *ptr;
+	int phnum = 0;
+
+	if (list_empty(&rproc->dump_segments))
+		return;
+
+	data_size = sizeof(*ehdr);
+	list_for_each_entry(segment, &rproc->dump_segments, node) {
+		data_size += sizeof(*phdr) + segment->size;
+
+		phnum++;
+	}
+
+	data = vmalloc(data_size);
+	if (!data)
+		return;
+
+	ehdr = data;
+
+	memset(ehdr, 0, sizeof(*ehdr));
+	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
+	ehdr->e_ident[EI_CLASS] = ELFCLASS32;
+	ehdr->e_ident[EI_DATA] = ELFDATA2LSB;
+	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
+	ehdr->e_ident[EI_OSABI] = ELFOSABI_NONE;
+	ehdr->e_type = ET_CORE;
+	ehdr->e_machine = EM_NONE;
+	ehdr->e_version = EV_CURRENT;
+	ehdr->e_entry = rproc->bootaddr;
+	ehdr->e_phoff = sizeof(*ehdr);
+	ehdr->e_ehsize = sizeof(*ehdr);
+	ehdr->e_phentsize = sizeof(*phdr);
+	ehdr->e_phnum = phnum;
+
+	phdr = data + ehdr->e_phoff;
+	offset = ehdr->e_phoff + sizeof(*phdr) * ehdr->e_phnum;
+	list_for_each_entry(segment, &rproc->dump_segments, node) {
+		memset(phdr, 0, sizeof(*phdr));
+		phdr->p_type = PT_LOAD;
+		phdr->p_offset = offset;
+		phdr->p_vaddr = segment->da;
+		phdr->p_paddr = segment->da;
+		phdr->p_filesz = segment->size;
+		phdr->p_memsz = segment->size;
+		phdr->p_flags = PF_R | PF_W | PF_X;
+		phdr->p_align = 0;
+
+		ptr = rproc_da_to_va(rproc, segment->da, segment->size);
+		if (!ptr) {
+			dev_err(&rproc->dev,
+				"invalid coredump segment (%pad, %zu)\n",
+				&segment->da, segment->size);
+			memset(data + offset, 0xff, segment->size);
+		} else {
+			memcpy(data + offset, ptr, segment->size);
+		}
+
+		offset += phdr->p_filesz;
+		phdr++;
+	}
+
+	dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL);
+}
+
+/**
+ * rproc_trigger_recovery() - recover a remoteproc
+ * @rproc: the remote processor
+ *
+ * The recovery is done by resetting all the virtio devices, that way all the
+ * rpmsg drivers will be reseted along with the remote processor making the
+ * remoteproc functional again.
+ *
+ * This function can sleep, so it cannot be called from atomic context.
+ */
+int rproc_trigger_recovery(struct rproc *rproc)
+{
+	const struct firmware *firmware_p;
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	dev_err(dev, "recovering %s\n", rproc->name);
+
+	ret = mutex_lock_interruptible(&rproc->lock);
+	if (ret)
+		return ret;
+
+	ret = rproc_stop(rproc, true);
+	if (ret)
+		goto unlock_mutex;
+
+	/* generate coredump */
+	rproc_coredump(rproc);
+
+	/* load firmware */
+	ret = request_firmware(&firmware_p, rproc->firmware, dev);
+	if (ret < 0) {
+		dev_err(dev, "request_firmware failed: %d\n", ret);
+		goto unlock_mutex;
+	}
+
+	/* boot the remote processor up again */
+	ret = rproc_start(rproc, firmware_p);
+
+	release_firmware(firmware_p);
+
+unlock_mutex:
+	mutex_unlock(&rproc->lock);
+	return ret;
+}
+
+/**
+ * rproc_crash_handler_work() - handle a crash
+ *
+ * This function needs to handle everything related to a crash, like cpu
+ * registers and stack dump, information to help to debug the fatal error, etc.
+ */
+static void rproc_crash_handler_work(struct work_struct *work)
+{
+	struct rproc *rproc = container_of(work, struct rproc, crash_handler);
+	struct device *dev = &rproc->dev;
+
+	dev_dbg(dev, "enter %s\n", __func__);
+
+	mutex_lock(&rproc->lock);
+
+	if (rproc->state == RPROC_CRASHED || rproc->state == RPROC_OFFLINE) {
+		/* handle only the first crash detected */
+		mutex_unlock(&rproc->lock);
+		return;
+	}
+
+	rproc->state = RPROC_CRASHED;
+	dev_err(dev, "handling crash #%u in %s\n", ++rproc->crash_cnt,
+		rproc->name);
+
+	mutex_unlock(&rproc->lock);
+
+	if (!rproc->recovery_disabled)
+		rproc_trigger_recovery(rproc);
+}
+
+/**
+ * rproc_boot() - boot a remote processor
+ * @rproc: handle of a remote processor
+ *
+ * Boot a remote processor (i.e. load its firmware, power it on, ...).
+ *
+ * If the remote processor is already powered on, this function immediately
+ * returns (successfully).
+ *
+ * Returns 0 on success, and an appropriate error value otherwise.
+ */
+int rproc_boot(struct rproc *rproc)
+{
+	const struct firmware *firmware_p;
+	struct device *dev;
+	int ret;
+
+	if (!rproc) {
+		pr_err("invalid rproc handle\n");
+		return -EINVAL;
+	}
+
+	dev = &rproc->dev;
+
+	ret = mutex_lock_interruptible(&rproc->lock);
+	if (ret) {
+		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
+		return ret;
+	}
+
+	if (rproc->state == RPROC_DELETED) {
+		ret = -ENODEV;
+		dev_err(dev, "can't boot deleted rproc %s\n", rproc->name);
+		goto unlock_mutex;
+	}
+
+	/* skip the boot process if rproc is already powered up */
+	if (atomic_inc_return(&rproc->power) > 1) {
+		ret = 0;
+		goto unlock_mutex;
+	}
+
+	dev_info(dev, "powering up %s\n", rproc->name);
+
+	/* load firmware */
+	ret = request_firmware(&firmware_p, rproc->firmware, dev);
+	if (ret < 0) {
+		dev_err(dev, "request_firmware failed: %d\n", ret);
+		goto downref_rproc;
+	}
+
+	ret = rproc_fw_boot(rproc, firmware_p);
+
+	release_firmware(firmware_p);
+
+downref_rproc:
+	if (ret)
+		atomic_dec(&rproc->power);
+unlock_mutex:
+	mutex_unlock(&rproc->lock);
+	return ret;
+}
+EXPORT_SYMBOL(rproc_boot);
+
+/**
+ * rproc_shutdown() - power off the remote processor
+ * @rproc: the remote processor
+ *
+ * Power off a remote processor (previously booted with rproc_boot()).
+ *
+ * In case @rproc is still being used by an additional user(s), then
+ * this function will just decrement the power refcount and exit,
+ * without really powering off the device.
+ *
+ * Every call to rproc_boot() must (eventually) be accompanied by a call
+ * to rproc_shutdown(). Calling rproc_shutdown() redundantly is a bug.
+ *
+ * Notes:
+ * - we're not decrementing the rproc's refcount, only the power refcount.
+ *   which means that the @rproc handle stays valid even after rproc_shutdown()
+ *   returns, and users can still use it with a subsequent rproc_boot(), if
+ *   needed.
+ */
+void rproc_shutdown(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	ret = mutex_lock_interruptible(&rproc->lock);
+	if (ret) {
+		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
+		return;
+	}
+
+	/* if the remote proc is still needed, bail out */
+	if (!atomic_dec_and_test(&rproc->power))
+		goto out;
+
+	ret = rproc_stop(rproc, false);
+	if (ret) {
+		atomic_inc(&rproc->power);
+		goto out;
+	}
+
+	/* clean up all acquired resources */
+	rproc_resource_cleanup(rproc);
+
+	rproc_disable_iommu(rproc);
+
+	/* Free the copy of the resource table */
+	kfree(rproc->cached_table);
+	rproc->cached_table = NULL;
+	rproc->table_ptr = NULL;
+out:
+	mutex_unlock(&rproc->lock);
+}
+EXPORT_SYMBOL(rproc_shutdown);
+
+/**
+ * rproc_get_by_phandle() - find a remote processor by phandle
+ * @phandle: phandle to the rproc
+ *
+ * Finds an rproc handle using the remote processor's phandle, and then
+ * return a handle to the rproc.
+ *
+ * This function increments the remote processor's refcount, so always
+ * use rproc_put() to decrement it back once rproc isn't needed anymore.
+ *
+ * Returns the rproc handle on success, and NULL on failure.
+ */
+#ifdef CONFIG_OF
+struct rproc *rproc_get_by_phandle(phandle phandle)
+{
+	struct rproc *rproc = NULL, *r;
+	struct device_node *np;
+
+	np = of_find_node_by_phandle(phandle);
+	if (!np)
+		return NULL;
+
+	mutex_lock(&rproc_list_mutex);
+	list_for_each_entry(r, &rproc_list, node) {
+		if (r->dev.parent && r->dev.parent->of_node == np) {
+			/* prevent underlying implementation from being removed */
+			if (!try_module_get(r->dev.parent->driver->owner)) {
+				dev_err(&r->dev, "can't get owner\n");
+				break;
+			}
+
+			rproc = r;
+			get_device(&rproc->dev);
+			break;
+		}
+	}
+	mutex_unlock(&rproc_list_mutex);
+
+	of_node_put(np);
+
+	return rproc;
+}
+#else
+struct rproc *rproc_get_by_phandle(phandle phandle)
+{
+	return NULL;
+}
+#endif
+EXPORT_SYMBOL(rproc_get_by_phandle);
+
+/**
+ * rproc_add() - register a remote processor
+ * @rproc: the remote processor handle to register
+ *
+ * Registers @rproc with the remoteproc framework, after it has been
+ * allocated with rproc_alloc().
+ *
+ * This is called by the platform-specific rproc implementation, whenever
+ * a new remote processor device is probed.
+ *
+ * Returns 0 on success and an appropriate error code otherwise.
+ *
+ * Note: this function initiates an asynchronous firmware loading
+ * context, which will look for virtio devices supported by the rproc's
+ * firmware.
+ *
+ * If found, those virtio devices will be created and added, so as a result
+ * of registering this remote processor, additional virtio drivers might be
+ * probed.
+ */
+int rproc_add(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	ret = device_add(dev);
+	if (ret < 0)
+		return ret;
+
+	dev_info(dev, "%s is available\n", rproc->name);
+
+	/* create debugfs entries */
+	rproc_create_debug_dir(rproc);
+
+	/* if rproc is marked always-on, request it to boot */
+	if (rproc->auto_boot) {
+		ret = rproc_trigger_auto_boot(rproc);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* expose to rproc_get_by_phandle users */
+	mutex_lock(&rproc_list_mutex);
+	list_add(&rproc->node, &rproc_list);
+	mutex_unlock(&rproc_list_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(rproc_add);
+
+/**
+ * rproc_type_release() - release a remote processor instance
+ * @dev: the rproc's device
+ *
+ * This function should _never_ be called directly.
+ *
+ * It will be called by the driver core when no one holds a valid pointer
+ * to @dev anymore.
+ */
+static void rproc_type_release(struct device *dev)
+{
+	struct rproc *rproc = container_of(dev, struct rproc, dev);
+
+	dev_info(&rproc->dev, "releasing %s\n", rproc->name);
+
+	idr_destroy(&rproc->notifyids);
+
+	if (rproc->index >= 0)
+		ida_simple_remove(&rproc_dev_index, rproc->index);
+
+	kfree(rproc->firmware);
+	kfree(rproc->ops);
+	kfree(rproc);
+}
+
+static const struct device_type rproc_type = {
+	.name		= "remoteproc",
+	.release	= rproc_type_release,
+};
+
+/**
+ * rproc_alloc() - allocate a remote processor handle
+ * @dev: the underlying device
+ * @name: name of this remote processor
+ * @ops: platform-specific handlers (mainly start/stop)
+ * @firmware: name of firmware file to load, can be NULL
+ * @len: length of private data needed by the rproc driver (in bytes)
+ *
+ * Allocates a new remote processor handle, but does not register
+ * it yet. if @firmware is NULL, a default name is used.
+ *
+ * This function should be used by rproc implementations during initialization
+ * of the remote processor.
+ *
+ * After creating an rproc handle using this function, and when ready,
+ * implementations should then call rproc_add() to complete
+ * the registration of the remote processor.
+ *
+ * On success the new rproc is returned, and on failure, NULL.
+ *
+ * Note: _never_ directly deallocate @rproc, even if it was not registered
+ * yet. Instead, when you need to unroll rproc_alloc(), use rproc_free().
+ */
+struct rproc *rproc_alloc(struct device *dev, const char *name,
+			  const struct rproc_ops *ops,
+			  const char *firmware, int len)
+{
+	struct rproc *rproc;
+	char *p, *template = "rproc-%s-fw";
+	int name_len;
+
+	if (!dev || !name || !ops)
+		return NULL;
+
+	if (!firmware) {
+		/*
+		 * If the caller didn't pass in a firmware name then
+		 * construct a default name.
+		 */
+		name_len = strlen(name) + strlen(template) - 2 + 1;
+		p = kmalloc(name_len, GFP_KERNEL);
+		if (!p)
+			return NULL;
+		snprintf(p, name_len, template, name);
+	} else {
+		p = kstrdup(firmware, GFP_KERNEL);
+		if (!p)
+			return NULL;
+	}
+
+	rproc = kzalloc(sizeof(struct rproc) + len, GFP_KERNEL);
+	if (!rproc) {
+		kfree(p);
+		return NULL;
+	}
+
+	rproc->ops = kmemdup(ops, sizeof(*ops), GFP_KERNEL);
+	if (!rproc->ops) {
+		kfree(p);
+		kfree(rproc);
+		return NULL;
+	}
+
+	rproc->firmware = p;
+	rproc->name = name;
+	rproc->priv = &rproc[1];
+	rproc->auto_boot = true;
+
+	device_initialize(&rproc->dev);
+	rproc->dev.parent = dev;
+	rproc->dev.type = &rproc_type;
+	rproc->dev.class = &rproc_class;
+	rproc->dev.driver_data = rproc;
+	idr_init(&rproc->notifyids);
+
+	/* Assign a unique device index and name */
+	rproc->index = ida_simple_get(&rproc_dev_index, 0, 0, GFP_KERNEL);
+	if (rproc->index < 0) {
+		dev_err(dev, "ida_simple_get failed: %d\n", rproc->index);
+		put_device(&rproc->dev);
+		return NULL;
+	}
+
+	dev_set_name(&rproc->dev, "remoteproc%d", rproc->index);
+
+	atomic_set(&rproc->power, 0);
+
+	/* Default to ELF loader if no load function is specified */
+	if (!rproc->ops->load) {
+		rproc->ops->load = rproc_elf_load_segments;
+		rproc->ops->parse_fw = rproc_elf_load_rsc_table;
+		rproc->ops->find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table;
+		rproc->ops->sanity_check = rproc_elf_sanity_check;
+		rproc->ops->get_boot_addr = rproc_elf_get_boot_addr;
+	}
+
+	mutex_init(&rproc->lock);
+
+	INIT_LIST_HEAD(&rproc->carveouts);
+	INIT_LIST_HEAD(&rproc->mappings);
+	INIT_LIST_HEAD(&rproc->traces);
+	INIT_LIST_HEAD(&rproc->rvdevs);
+	INIT_LIST_HEAD(&rproc->subdevs);
+	INIT_LIST_HEAD(&rproc->dump_segments);
+
+	INIT_WORK(&rproc->crash_handler, rproc_crash_handler_work);
+
+	rproc->state = RPROC_OFFLINE;
+
+	return rproc;
+}
+EXPORT_SYMBOL(rproc_alloc);
+
+/**
+ * rproc_free() - unroll rproc_alloc()
+ * @rproc: the remote processor handle
+ *
+ * This function decrements the rproc dev refcount.
+ *
+ * If no one holds any reference to rproc anymore, then its refcount would
+ * now drop to zero, and it would be freed.
+ */
+void rproc_free(struct rproc *rproc)
+{
+	put_device(&rproc->dev);
+}
+EXPORT_SYMBOL(rproc_free);
+
+/**
+ * rproc_put() - release rproc reference
+ * @rproc: the remote processor handle
+ *
+ * This function decrements the rproc dev refcount.
+ *
+ * If no one holds any reference to rproc anymore, then its refcount would
+ * now drop to zero, and it would be freed.
+ */
+void rproc_put(struct rproc *rproc)
+{
+	module_put(rproc->dev.parent->driver->owner);
+	put_device(&rproc->dev);
+}
+EXPORT_SYMBOL(rproc_put);
+
+/**
+ * rproc_del() - unregister a remote processor
+ * @rproc: rproc handle to unregister
+ *
+ * This function should be called when the platform specific rproc
+ * implementation decides to remove the rproc device. it should
+ * _only_ be called if a previous invocation of rproc_add()
+ * has completed successfully.
+ *
+ * After rproc_del() returns, @rproc isn't freed yet, because
+ * of the outstanding reference created by rproc_alloc. To decrement that
+ * one last refcount, one still needs to call rproc_free().
+ *
+ * Returns 0 on success and -EINVAL if @rproc isn't valid.
+ */
+int rproc_del(struct rproc *rproc)
+{
+	if (!rproc)
+		return -EINVAL;
+
+	/* if rproc is marked always-on, rproc_add() booted it */
+	/* TODO: make sure this works with rproc->power > 1 */
+	if (rproc->auto_boot)
+		rproc_shutdown(rproc);
+
+	mutex_lock(&rproc->lock);
+	rproc->state = RPROC_DELETED;
+	mutex_unlock(&rproc->lock);
+
+	rproc_delete_debug_dir(rproc);
+
+	/* the rproc is downref'ed as soon as it's removed from the klist */
+	mutex_lock(&rproc_list_mutex);
+	list_del(&rproc->node);
+	mutex_unlock(&rproc_list_mutex);
+
+	device_del(&rproc->dev);
+
+	return 0;
+}
+EXPORT_SYMBOL(rproc_del);
+
+/**
+ * rproc_add_subdev() - add a subdevice to a remoteproc
+ * @rproc: rproc handle to add the subdevice to
+ * @subdev: subdev handle to register
+ *
+ * Caller is responsible for populating optional subdevice function pointers.
+ */
+void rproc_add_subdev(struct rproc *rproc, struct rproc_subdev *subdev)
+{
+	list_add_tail(&subdev->node, &rproc->subdevs);
+}
+EXPORT_SYMBOL(rproc_add_subdev);
+
+/**
+ * rproc_remove_subdev() - remove a subdevice from a remoteproc
+ * @rproc: rproc handle to remove the subdevice from
+ * @subdev: subdev handle, previously registered with rproc_add_subdev()
+ */
+void rproc_remove_subdev(struct rproc *rproc, struct rproc_subdev *subdev)
+{
+	list_del(&subdev->node);
+}
+EXPORT_SYMBOL(rproc_remove_subdev);
+
+/**
+ * rproc_get_by_child() - acquire rproc handle of @dev's ancestor
+ * @dev:	child device to find ancestor of
+ *
+ * Returns the ancestor rproc instance, or NULL if not found.
+ */
+struct rproc *rproc_get_by_child(struct device *dev)
+{
+	for (dev = dev->parent; dev; dev = dev->parent) {
+		if (dev->type == &rproc_type)
+			return dev->driver_data;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(rproc_get_by_child);
+
+/**
+ * rproc_report_crash() - rproc crash reporter function
+ * @rproc: remote processor
+ * @type: crash type
+ *
+ * This function must be called every time a crash is detected by the low-level
+ * drivers implementing a specific remoteproc. This should not be called from a
+ * non-remoteproc driver.
+ *
+ * This function can be called from atomic/interrupt context.
+ */
+void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type)
+{
+	if (!rproc) {
+		pr_err("NULL rproc pointer\n");
+		return;
+	}
+
+	dev_err(&rproc->dev, "crash detected in %s: type %s\n",
+		rproc->name, rproc_crash_to_string(type));
+
+	/* create a new task to handle the error */
+	schedule_work(&rproc->crash_handler);
+}
+EXPORT_SYMBOL(rproc_report_crash);
+
+static int __init remoteproc_init(void)
+{
+	rproc_init_sysfs();
+	rproc_init_debugfs();
+
+	return 0;
+}
+subsys_initcall(remoteproc_init);
+
+static void __exit remoteproc_exit(void)
+{
+	ida_destroy(&rproc_dev_index);
+
+	rproc_exit_debugfs();
+	rproc_exit_sysfs();
+}
+module_exit(remoteproc_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Generic Remote Processor Framework");