path: root/drivers/remoteproc/remoteproc_core.c

/*
 * 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/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;

	dev_dbg(dev, "vring%d: va %p dma %llx size %x idr %d\n", i, va,
				(unsigned long long)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 %x, qsz %d, align %d\n",
				i, vring->da, vring->num, vring->align);

	/* make sure reserved bytes are zeroes */
	if (vring->reserved) {
		dev_err(dev, "vring rsc has non zero reserved bytes\n");
		return -EINVAL;
	}

	/* verify queue size and vring alignment are