drivers/vme/vme.c

/*
 * VME Bridge Framework
 *
 * Author: Martyn Welch <martyn.welch@ge.com>
 * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
 *
 * Based on work by Tom Armistead and Ajit Prem
 * Copyright 2004 Motorola Inc.
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/poll.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/syscalls.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/vme.h>

#include "vme_bridge.h"

/* Bitmask and list of registered buses both protected by common mutex */
static unsigned int vme_bus_numbers;
static LIST_HEAD(vme_bus_list);
static DEFINE_MUTEX(vme_buses_lock);

static int __init vme_init(void);

static struct vme_dev *dev_to_vme_dev(struct device *dev)
{
	return container_of(dev, struct vme_dev, dev);
}

/*
 * Find the bridge that the resource is associated with.
 */
static struct vme_bridge *find_bridge(struct vme_resource *resource)
{
	/* Get list to search */
	switch (resource->type) {
	case VME_MASTER:
		return list_entry(resource->entry, struct vme_master_resource,
			list)->parent;
		break;
	case VME_SLAVE:
		return list_entry(resource->entry, struct vme_slave_resource,
			list)->parent;
		break;
	case VME_DMA:
		return list_entry(resource->entry, struct vme_dma_resource,
			list)->parent;
		break;
	case VME_LM:
		return list_entry(resource->entry, struct vme_lm_resource,
			list)->parent;
		break;
	default:
		printk(KERN_ERR "Unknown resource type\n");
		return NULL;
		break;
	}
}

/*
 * Allocate a contiguous block of memory for use by the driver. This is used to
 * create the buffers for the slave windows.
 */
void *vme_alloc_consistent(struct vme_resource *resource, size_t size,
	dma_addr_t *dma)
{
	struct vme_bridge *bridge;

	if (resource == NULL) {
		printk(KERN_ERR "No resource\n");
		return NULL;
	}

	bridge = find_bridge(resource);
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find bridge\n");
		return NULL;
	}

	if (bridge->parent == NULL) {
		printk(KERN_ERR "Dev entry NULL for bridge %s\n", bridge->name);
		return NULL;
	}

	if (bridge->alloc_consistent == NULL) {
		printk(KERN_ERR "alloc_consistent not supported by bridge %s\n",
		       bridge->name);
		return NULL;
	}

	return bridge->alloc_consistent(bridge->parent, size, dma);
}
EXPORT_SYMBOL(vme_alloc_consistent);

/*
 * Free previously allocated contiguous block of memory.
 */
void vme_free_consistent(struct vme_resource *resource, size_t size,
	void *vaddr, dma_addr_t dma)
{
	struct vme_bridge *bridge;

	if (resource == NULL) {
		printk(KERN_ERR "No resource\n");
		return;
	}

	bridge = find_bridge(resource);
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find bridge\n");
		return;
	}

	if (bridge->parent == NULL) {
		printk(KERN_ERR "Dev entry NULL for bridge %s\n", bridge->name);
		return;
	}

	if (bridge->free_consistent == NULL) {
		printk(KERN_ERR "free_consistent not supported by bridge %s\n",
		       bridge->name);
		return;
	}

	bridge->free_consistent(bridge->parent, size, vaddr, dma);
}
EXPORT_SYMBOL(vme_free_consistent);

size_t vme_get_size(struct vme_resource *resource)
{
	int enabled, retval;
	unsigned long long base, size;
	dma_addr_t buf_base;
	u32 aspace, cycle, dwidth;

	switch (resource->type) {
	case VME_MASTER:
		retval = vme_master_get(resource, &enabled, &base, &size,
			&aspace, &cycle, &dwidth);
		if (retval)
			return 0;

		return size;
		break;
	case VME_SLAVE:
		retval = vme_slave_get(resource, &enabled, &base, &size,
			&buf_base, &aspace, &cycle);
		if (retval)
			return 0;

		return size;
		break;
	case VME_DMA:
		return 0;
		break;
	default:
		printk(KERN_ERR "Unknown resource type\n");
		return 0;
		break;
	}
}
EXPORT_SYMBOL(vme_get_size);

int vme_check_window(u32 aspace, unsigned long long vme_base,
		     unsigned long long size)
{
	int retval = 0;

	switch (aspace) {
	case VME_A16:
		if (((vme_base + size) > VME_A16_MAX) ||
				(vme_base > VME_A16_MAX))
			retval = -EFAULT;
		break;
	case VME_A24:
		if (((vme_base + size) > VME_A24_MAX) ||
				(vme_base > VME_A24_MAX))
			retval = -EFAULT;
		break;
	case VME_A32:
		if (((vme_base + size) > VME_A32_MAX) ||
				(vme_base > VME_A32_MAX))
			retval = -EFAULT;
		break;
	case VME_A64:
		if ((size != 0) && (vme_base > U64_MAX + 1 - size))
			retval = -EFAULT;
		break;
	case VME_CRCSR:
		if (((vme_base + size) > VME_CRCSR_MAX) ||
				(vme_base > VME_CRCSR_MAX))
			retval = -EFAULT;
		break;
	case VME_USER1:
	case VME_USER2:
	case VME_USER3:
	case VME_USER4:
		/* User Defined */
		break;
	default:
		printk(KERN_ERR "Invalid address space\n");
		retval = -EINVAL;
		break;
	}

	return retval;
}
EXPORT_SYMBOL(vme_check_window);

static u32 vme_get_aspace(int am)
{
	switch (am) {
	case 0x29:
	case 0x2D:
		return VME_A16;
	case 0x38:
	case 0x39:
	case 0x3A:
	case 0x3B:
	case 0x3C:
	case 0x3D:
	case 0x3E:
	case 0x3F:
		return VME_A24;
	case 0x8:
	case 0x9:
	case 0xA:
	case 0xB:
	case 0xC:
	case 0xD:
	case 0xE:
	case 0xF:
		return VME_A32;
	case 0x0:
	case 0x1:
	case 0x3:
		return VME_A64;
	}

	return 0;
}

/*
 * Request a slave image with specific attributes, return some unique
 * identifier.
 */
struct vme_resource *vme_slave_request(struct vme_dev *vdev, u32 address,
	u32 cycle)
{
	struct vme_bridge *bridge;
	struct list_head *slave_pos = NULL;
	struct vme_slave_resource *allocated_image = NULL;
	struct vme_slave_resource *slave_image = NULL;
	struct vme_resource *resource = NULL;

	bridge = vdev->bridge;
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find VME bus\n");
		goto err_bus;
	}

	/* Loop through slave resources */
	list_for_each(slave_pos, &bridge->slave_resources) {
		slave_image = list_entry(slave_pos,
			struct vme_slave_resource, list);

		if (slave_image == NULL) {
			printk(KERN_ERR "Registered NULL Slave resource\n");
			continue;
		}

		/* Find an unlocked and compatible image */
		mutex_lock(&slave_image->mtx);
		if (((slave_image->address_attr & address) == address) &&
			((slave_image->cycle_attr & cycle) == cycle) &&
			(slave_image->locked == 0)) {

			slave_image->locked = 1;
			mutex_unlock(&slave_image->mtx);
			allocated_image = slave_image;
			break;
		}
		mutex_unlock(&slave_image->mtx);
	}

	/* No free image */
	if (allocated_image == NULL)
		goto err_image;

	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
	if (resource == NULL) {
		printk(KERN_WARNING "Unable to allocate resource structure\n");
		goto err_alloc;
	}
	resource->type = VME_SLAVE;
	resource->entry = &allocated_image->list;

	return resource;

err_alloc:
	/* Unlock image */
	mutex_lock(&slave_image->mtx);
	slave_image->locked = 0;
	mutex_unlock(&slave_image->mtx);
err_image:
err_bus:
	return NULL;
}
EXPORT_SYMBOL(vme_slave_request);

int vme_slave_set(struct vme_resource *resource, int enabled,
	unsigned long long vme_base, unsigned long long size,
	dma_addr_t buf_base, u32 aspace, u32 cycle)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_slave_resource *image;
	int retval;

	if (resource->type != VME_SLAVE) {
		printk(KERN_ERR "Not a slave resource\n");
		return -EINVAL;
	}

	image = list_entry(resource->entry, struct vme_slave_resource, list);

	if (bridge->slave_set == NULL) {
		printk(KERN_ERR "Function not supported\n");
		return -ENOSYS;
	}

	if (!(((image->address_attr & aspace) == aspace) &&
		((image->cycle_attr & cycle) == cycle))) {
		printk(KERN_ERR "Invalid attributes\n");
		return -EINVAL;
	}

	retval = vme_check_window(aspace, vme_base, size);
	if (retval)
		return retval;

	return bridge->slave_set(image, enabled, vme_base, size, buf_base,
		aspace, cycle);
}
EXPORT_SYMBOL(vme_slave_set);

int vme_slave_get(struct vme_resource *resource, int *enabled,
	unsigned long long *vme_base, unsigned long long *size,
	dma_addr_t *buf_base, u32 *aspace, u32 *cycle)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_slave_resource *image;

	if (resource->type != VME_SLAVE) {
		printk(KERN_ERR "Not a slave resource\n");
		return -EINVAL;
	}

	image = list_entry(resource->entry, struct vme_slave_resource, list);

	if (bridge->slave_get == NULL) {
		printk(KERN_ERR "vme_slave_get not supported\n");
		return -EINVAL;
	}

	return bridge->slave_get(image, enabled, vme_base, size, buf_base,
		aspace, cycle);
}
EXPORT_SYMBOL(vme_slave_get);

void vme_slave_free(struct vme_resource *resource)
{
	struct vme_slave_resource *slave_image;

	if (resource->type != VME_SLAVE) {
		printk(KERN_ERR "Not a slave resource\n");
		return;
	}

	slave_image = list_entry(resource->entry, struct vme_slave_resource,
		list);
	if (slave_image == NULL) {
		printk(KERN_ERR "Can't find slave resource\n");
		return;
	}

	/* Unlock image */
	mutex_lock(&slave_image->mtx);
	if (slave_image->locked == 0)
		printk(KERN_ERR "Image is already free\n");

	slave_image->locked = 0;
	mutex_unlock(&slave_image->mtx);

	/* Free up resource memory */
	kfree(resource);
}
EXPORT_SYMBOL(vme_slave_free);

/*
 * Request a master image with specific attributes, return some unique
 * identifier.
 */
struct vme_resource *vme_master_request(struct vme_dev *vdev, u32 address,
	u32 cycle, u32 dwidth)
{
	struct vme_bridge *bridge;
	struct list_head *master_pos = NULL;
	struct vme_master_resource *allocated_image = NULL;
	struct vme_master_resource *master_image = NULL;
	struct vme_resource *resource = NULL;

	bridge = vdev->bridge;
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find VME bus\n");
		goto err_bus;
	}

	/* Loop through master resources */
	list_for_each(master_pos, &bridge->master_resources) {
		master_image = list_entry(master_pos,
			struct vme_master_resource, list);

		if (master_image == NULL) {
			printk(KERN_WARNING "Registered NULL master resource\n");
			continue;
		}

		/* Find an unlocked and compatible image */
		spin_lock(&master_image->lock);
		if (((master_image->address_attr & address) == address) &&
			((master_image->cycle_attr & cycle) == cycle) &&
			((master_image->width_attr & dwidth) == dwidth) &&
			(master_image->locked == 0)) {

			master_image->locked = 1;
			spin_unlock(&master_image->lock);
			allocated_image = master_image;
			break;
		}
		spin_unlock(&master_image->lock);
	}

	/* Check to see if we found a resource */
	if (allocated_image == NULL) {
		printk(KERN_ERR "Can't find a suitable resource\n");
		goto err_image;
	}

	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
	if (resource == NULL) {
		printk(KERN_ERR "Unable to allocate resource structure\n");
		goto err_alloc;
	}
	resource->type = VME_MASTER;
	resource->entry = &allocated_image->list;

	return resource;

err_alloc:
	/* Unlock image */
	spin_lock(&master_image->lock);
	master_image->locked = 0;
	spin_unlock(&master_image->lock);
err_image:
err_bus:
	return NULL;
}
EXPORT_SYMBOL(vme_master_request);

int vme_master_set(struct vme_resource *resource, int enabled,
	unsigned long long vme_base, unsigned long long size, u32 aspace,
	u32 cycle, u32 dwidth)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_master_resource *image;
	int retval;

	if (resource->type != VME_MASTER) {
		printk(KERN_ERR "Not a master resource\n");
		return -EINVAL;
	}

	image = list_entry(resource->entry, struct vme_master_resource, list);

	if (bridge->master_set == NULL) {
		printk(KERN_WARNING "vme_master_set not supported\n");
		return -EINVAL;
	}

	if (!(((image->address_attr & aspace) == aspace) &&
		((image->cycle_attr & cycle) == cycle) &&
		((image->width_attr & dwidth) == dwidth))) {
		printk(KERN_WARNING "Invalid attributes\n");
		return -EINVAL;
	}

	retval = vme_check_window(aspace, vme_base, size);
	if (retval)
		return retval;

	return bridge->master_set(image, enabled, vme_base, size, aspace,
		cycle, dwidth);
}
EXPORT_SYMBOL(vme_master_set);

int vme_master_get(struct vme_resource *resource, int *enabled,
	unsigned long long *vme_base, unsigned long long *size, u32 *aspace,
	u32 *cycle, u32 *dwidth)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_master_resource *image;

	if (resource->type != VME_MASTER) {
		printk(KERN_ERR "Not a master resource\n");
		return -EINVAL;
	}

	image = list_entry(resource->entry, struct vme_master_resource, list);

	if (bridge->master_get == NULL) {
		printk(KERN_WARNING "%s not supported\n", __func__);
		return -EINVAL;
	}

	return bridge->master_get(image, enabled, vme_base, size, aspace,
		cycle, dwidth);
}
EXPORT_SYMBOL(vme_master_get);

/*
 * Read data out of VME space into a buffer.
 */
ssize_t vme_master_read(struct vme_resource *resource, void *buf, size_t count,
	loff_t offset)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_master_resource *image;
	size_t length;

	if (bridge->master_read == NULL) {
		printk(KERN_WARNING "Reading from resource not supported\n");
		return -EINVAL;
	}

	if (resource->type != VME_MASTER) {
		printk(KERN_ERR "Not a master resource\n");
		return -EINVAL;
	}

	image = list_entry(resource->entry, struct vme_master_resource, list);

	length = vme_get_size(resource);

	if (offset > length) {
		printk(KERN_WARNING "Invalid Offset\n");
		return -EFAULT;
	}

	if ((offset + count) > length)
		count = length - offset;

	return bridge->master_read(image, buf, count, offset);

}
EXPORT_SYMBOL(vme_master_read);

/*
 * Write data out to VME space from a buffer.
 */
ssize_t vme_master_write(struct vme_resource *resource, void *buf,
	size_t count, loff_t offset)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_master_resource *image;
	size_t length;

	if (bridge->master_write == NULL) {
		printk(KERN_WARNING "Writing to resource not supported\n");
		return -EINVAL;
	}

	if (resource->type != VME_MASTER) {
		printk(KERN_ERR "Not a master resource\n");
		return -EINVAL;
	}

	image = list_entry(resource->entry, struct vme_master_resource, list);

	length = vme_get_size(resource);

	if (offset > length) {
		printk(KERN_WARNING "Invalid Offset\n");
		return -EFAULT;
	}

	if ((offset + count) > length)
		count = length - offset;

	return bridge->master_write(image, buf, count, offset);
}
EXPORT_SYMBOL(vme_master_write);

/*
 * Perform RMW cycle to provided location.
 */
unsigned int vme_master_rmw(struct vme_resource *resource, unsigned int mask,
	unsigned int compare, unsigned int swap, loff_t offset)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_master_resource *image;

	if (bridge->master_rmw == NULL) {
		printk(KERN_WARNING "Writing to resource not supported\n");
		return -EINVAL;
	}

	if (resource->type != VME_MASTER) {
		printk(KERN_ERR "Not a master resource\n");
		return -EINVAL;
	}

	image = list_entry(resource->entry, struct vme_master_resource, list);

	return bridge->master_rmw(image, mask, compare, swap, offset);
}
EXPORT_SYMBOL(vme_master_rmw);

int vme_master_mmap(struct vme_resource *resource, struct vm_area_struct *vma)
{
	struct vme_master_resource *image;
	phys_addr_t phys_addr;
	unsigned long vma_size;

	if (resource->type != VME_MASTER) {
		pr_err("Not a master resource\n");
		return -EINVAL;
	}

	image = list_entry(resource->entry, struct vme_master_resource, list);
	phys_addr = image->bus_resource.start + (vma->vm_pgoff << PAGE_SHIFT);
	vma_size = vma->vm_end - vma->vm_start;

	if (phys_addr + vma_size > image->bus_resource.end + 1) {
		pr_err("Map size cannot exceed the window size\n");
		return -EFAULT;
	}

	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

	return vm_iomap_memory(vma, phys_addr, vma->vm_end - vma->vm_start);
}
EXPORT_SYMBOL(vme_master_mmap);

void vme_master_free(struct vme_resource *resource)
{
	struct vme_master_resource *master_image;

	if (resource->type != VME_MASTER) {
		printk(KERN_ERR "Not a master resource\n");
		return;
	}

	master_image = list_entry(resource->entry, struct vme_master_resource,
		list);
	if (master_image == NULL) {
		printk(KERN_ERR "Can't find master resource\n");
		return;
	}

	/* Unlock image */
	spin_lock(&master_image->lock);
	if (master_image->locked == 0)
		printk(KERN_ERR "Image is already free\n");

	master_image->locked = 0;
	spin_unlock(&master_image->lock);

	/* Free up resource memory */
	kfree(resource);
}
EXPORT_SYMBOL(vme_master_free);

/*
 * Request a DMA controller with specific attributes, return some unique
 * identifier.
 */
struct vme_resource *vme_dma_request(struct vme_dev *vdev, u32 route)
{
	struct vme_bridge *bridge;
	struct list_head *dma_pos = NULL;
	struct vme_dma_resource *allocated_ctrlr = NULL;
	struct vme_dma_resource *dma_ctrlr = NULL;
	struct vme_resource *resource = NULL;

	/* XXX Not checking resource attributes */
	printk(KERN_ERR "No VME resource Attribute tests done\n");

	bridge = vdev->bridge;
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find VME bus\n");
		goto err_bus;
	}

	/* Loop through DMA resources */
	list_for_each(dma_pos, &bridge->dma_resources) {
		dma_ctrlr = list_entry(dma_pos,
			struct vme_dma_resource, list);

		if (dma_ctrlr == NULL) {
			printk(KERN_ERR "Registered NULL DMA resource\n");
			continue;
		}

		/* Find an unlocked and compatible controller */
		mutex_lock(&dma_ctrlr->mtx);
		if (((dma_ctrlr->route_attr & route) == route) &&
			(dma_ctrlr->locked == 0)) {

			dma_ctrlr->locked = 1;
			mutex_unlock(&dma_ctrlr->mtx);
			allocated_ctrlr = dma_ctrlr;
			break;
		}
		mutex_unlock(&dma_ctrlr->mtx);
	}

	/* Check to see if we found a resource */
	if (allocated_ctrlr == NULL)
		goto err_ctrlr;

	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
	if (resource == NULL) {
		printk(KERN_WARNING "Unable to allocate resource structure\n");
		goto err_alloc;
	}
	resource->type = VME_DMA;
	resource->entry = &allocated_ctrlr->list;

	return resource;

err_alloc:
	/* Unlock image */
	mutex_lock(&dma_ctrlr->mtx);
	dma_ctrlr->locked = 0;
	mutex_unlock(&dma_ctrlr->mtx);
err_ctrlr:
err_bus:
	return NULL;
}
EXPORT_SYMBOL(vme_dma_request);

/*
 * Start new list
 */
struct vme_dma_list *vme_new_dma_list(struct vme_resource *resource)
{
	struct vme_dma_resource *ctrlr;
	struct vme_dma_list *dma_list;

	if (resource->type != VME_DMA) {
		printk(KERN_ERR "Not a DMA resource\n");
		return NULL;
	}

	ctrlr = list_entry(resource->entry, struct vme_dma_resource, list);

	dma_list = kmalloc(sizeof(struct vme_dma_list), GFP_KERNEL);
	if (dma_list == NULL) {
		printk(KERN_ERR "Unable to allocate memory for new DMA list\n");
		return NULL;
	}
	INIT_LIST_HEAD(&dma_list->entries);
	dma_list->parent = ctrlr;
	mutex_init(&dma_list->mtx);

	return dma_list;
}
EXPORT_SYMBOL(vme_new_dma_list);

/*
 * Create "Pattern" type attributes
 */
struct vme_dma_attr *vme_dma_pattern_attribute(u32 pattern, u32 type)
{
	struct vme_dma_attr *attributes;
	struct vme_dma_pattern *pattern_attr;

	attributes = kmalloc(sizeof(struct vme_dma_attr), GFP_KERNEL);
	if (attributes == NULL) {
		printk(KERN_ERR "Unable to allocate memory for attributes structure\n");
		goto err_attr;
	}

	pattern_attr = kmalloc(sizeof(struct vme_dma_pattern), GFP_KERNEL);
	if (pattern_attr == NULL) {
		printk(KERN_ERR "Unable to allocate memory for pattern attributes\n");
		goto err_pat;
	}

	attributes->type = VME_DMA_PATTERN;
	attributes->private = (void *)pattern_attr;

	pattern_attr->pattern = pattern;
	pattern_attr->type = type;

	return attributes;

err_pat:
	kfree(attributes);
err_attr:
	return NULL;
}
EXPORT_SYMBOL(vme_dma_pattern_attribute);

/*
 * Create "PCI" type attributes
 */
struct vme_dma_attr *vme_dma_pci_attribute(dma_addr_t address)
{
	struct vme_dma_attr *attributes;
	struct vme_dma_pci *pci_attr;

	/* XXX Run some sanity checks here */

	attributes = kmalloc(sizeof(struct vme_dma_attr), GFP_KERNEL);
	if (attributes == NULL) {
		printk(KERN_ERR "Unable to allocate memory for attributes structure\n");
		goto err_attr;
	}

	pci_attr = kmalloc(sizeof(struct vme_dma_pci), GFP_KERNEL);
	if (pci_attr == NULL) {
		printk(KERN_ERR "Unable to allocate memory for PCI attributes\n");
		goto err_pci;
	}



	attributes->type = VME_DMA_PCI;
	attributes->private = (void *)pci_attr;

	pci_attr->address = address;

	return attributes;

err_pci:
	kfree(attributes);
err_attr:
	return NULL;
}
EXPORT_SYMBOL(vme_dma_pci_attribute);

/*
 * Create "VME" type attributes
 */
struct vme_dma_attr *vme_dma_vme_attribute(unsigned long long address,
	u32 aspace, u32 cycle, u32 dwidth)
{
	struct vme_dma_attr *attributes;
	struct vme_dma_vme *vme_attr;

	attributes = kmalloc(
		sizeof(struct vme_dma_attr), GFP_KERNEL);
	if (attributes == NULL) {
		printk(KERN_ERR "Unable to allocate memory for attributes structure\n");
		goto err_attr;
	}

	vme_attr = kmalloc(sizeof(struct vme_dma_vme), GFP_KERNEL);
	if (vme_attr == NULL) {
		printk(KERN_ERR "Unable to allocate memory for VME attributes\n");
		goto err_vme;
	}

	attributes->type = VME_DMA_VME;
	attributes->private = (void *)vme_attr;

	vme_attr->address = address;
	vme_attr->aspace = aspace;
	vme_attr->cycle = cycle;
	vme_attr->dwidth = dwidth;

	return attributes;

err_vme:
	kfree(attributes);
err_attr:
	return NULL;
}
EXPORT_SYMBOL(vme_dma_vme_attribute);

/*
 * Free attribute
 */
void vme_dma_free_attribute(struct vme_dma_attr *attributes)
{
	kfree(attributes->private);
	kfree(attributes);
}
EXPORT_SYMBOL(vme_dma_free_attribute);

int vme_dma_list_add(struct vme_dma_list *list, struct vme_dma_attr *src,
	struct vme_dma_attr *dest, size_t count)
{
	struct vme_bridge *bridge = list->parent->parent;
	int retval;

	if (bridge->dma_list_add == NULL) {
		printk(KERN_WARNING "Link List DMA generation not supported\n");
		return -EINVAL;
	}

	if (!mutex_trylock(&list->mtx)) {
		printk(KERN_ERR "Link List already submitted\n");
		return -EINVAL;
	}

	retval = bridge->dma_list_add(list, src, dest, count);

	mutex_unlock(&list->mtx);

	return retval;
}
EXPORT_SYMBOL(vme_dma_list_add);

int vme_dma_list_exec(struct vme_dma_list *list)
{
	struct vme_bridge *bridge = list->parent->parent;
	int retval;

	if (bridge->dma_list_exec == NULL) {
		printk(KERN_ERR "Link List DMA execution not supported\n");
		return -EINVAL;
	}

	mutex_lock(&list->mtx);

	retval = bridge->dma_list_exec(list);

	mutex_unlock(&list->mtx);

	return retval;
}
EXPORT_SYMBOL(vme_dma_list_exec);

int vme_dma_list_free(struct vme_dma_list *list)
{
	struct vme_bridge *bridge = list->parent->parent;
	int retval;

	if (bridge->dma_list_empty == NULL) {
		printk(KERN_WARNING "Emptying of Link Lists not supported\n");
		return -EINVAL;
	}

	if (!mutex_trylock(&list->mtx)) {
		printk(KERN_ERR "Link List in use\n");
		return -EINVAL;
	}

	/*
	 * Empty out all of the entries from the DMA list. We need to go to the
	 * low level driver as DMA entries are driver specific.
	 */
	retval = bridge->dma_list_empty(list);
	if (retval) {
		printk(KERN_ERR "Unable to empty link-list entries\n");
		mutex_unlock(&list->mtx);
		return retval;
	}
	mutex_unlock(&list->mtx);
	kfree(list);

	return retval;
}
EXPORT_SYMBOL(vme_dma_list_free);

int vme_dma_free(struct vme_resource *resource)
{
	struct vme_dma_resource *ctrlr;

	if (resource->type != VME_DMA) {
		printk(KERN_ERR "Not a DMA resource\n");
		return -EINVAL;
	}

	ctrlr = list_entry(resource->entry, struct vme_dma_resource, list);

	if (!mutex_trylock(&ctrlr->mtx)) {
		printk(KERN_ERR "Resource busy, can't free\n");
		return -EBUSY;
	}

	if (!(list_empty(&ctrlr->pending) && list_empty(&ctrlr->running))) {
		printk(KERN_WARNING "Resource still processing transfers\n");
		mutex_unlock(&ctrlr->mtx);
		return -EBUSY;
	}

	ctrlr->locked = 0;

	mutex_unlock(&ctrlr->mtx);

	kfree(resource);

	return 0;
}
EXPORT_SYMBOL(vme_dma_free);

void vme_bus_error_handler(struct vme_bridge *bridge,
			   unsigned long long address, int am)
{
	struct list_head *handler_pos = NULL;
	struct vme_error_handler *handler;
	int handler_triggered = 0;
	u32 aspace = vme_get_aspace(am);

	list_for_each(handler_pos, &bridge->vme_error_handlers) {
		handler = list_entry(handler_pos, struct vme_error_handler,
				     list);
		if ((aspace == handler->aspace) &&
		    (address >= handler->start) &&
		    (address < handler->end)) {
			if (!handler->num_errors)
				handler->first_error = address;
			if (handler->num_errors != UINT_MAX)
				handler->num_errors++;
			handler_triggered = 1;
		}
	}

	if (!handler_triggered)
		dev_err(bridge->parent,
			"Unhandled VME access error at address 0x%llx\n",
			address);
}
EXPORT_SYMBOL(vme_bus_error_handler);

struct vme_error_handler *vme_register_error_handler(
	struct vme_bridge *bridge, u32 aspace,
	unsigned long long address, size_t len)
{
	struct vme_error_handler *handler;

	handler = kmalloc(sizeof(*handler), GFP_KERNEL);
	if (!handler)
		return NULL;

	handler->aspace = aspace;
	handler->start = address;
	handler->end = address + len;
	handler->num_errors = 0;
	handler->first_error = 0;
	list_add_tail(&handler->list, &bridge->vme_error_handlers);

	return handler;
}
EXPORT_SYMBOL(vme_register_error_handler);

void vme_unregister_error_handler(struct vme_error_handler *handler)
{
	list_del(&handler->list);
	kfree(handler);
}
EXPORT_SYMBOL(vme_unregister_error_handler);

void vme_irq_handler(struct vme_bridge *bridge, int level, int statid)
{
	void (*call)(int, int, void *);
	void *priv_data;

	call = bridge->irq[level - 1].callback[statid].func;
	priv_data = bridge->irq[level - 1].callback[statid].priv_data;

	if (call != NULL)
		call(level, statid, priv_data);
	else
		printk(KERN_WARNING "Spurious VME interrupt, level:%x, vector:%x\n",
		       level, statid);
}
EXPORT_SYMBOL(vme_irq_handler);

int vme_irq_request(struct vme_dev *vdev, int level, int statid,
	void (*callback)(int, int, void *),
	void *priv_data)
{
	struct vme_bridge *bridge;

	bridge = vdev->bridge;
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find VME bus\n");
		return -EINVAL;
	}

	if ((level < 1) || (level > 7)) {
		printk(KERN_ERR "Invalid interrupt level\n");
		return -EINVAL;
	}

	if (bridge->irq_set == NULL) {
		printk(KERN_ERR "Configuring interrupts not supported\n");
		return -EINVAL;
	}

	mutex_lock(&bridge->irq_mtx);

	if (bridge->irq[level - 1].callback[statid].func) {
		mutex_unlock(&bridge->irq_mtx);
		printk(KERN_WARNING "VME Interrupt already taken\n");
		return -EBUSY;
	}

	bridge->irq[level - 1].count++;
	bridge->irq[level - 1].callback[statid].priv_data = priv_data;
	bridge->irq[level - 1].callback[statid].func = callback;

	/* Enable IRQ level */
	bridge->irq_set(bridge, level, 1, 1);

	mutex_unlock(&bridge->irq_mtx);

	return 0;
}
EXPORT_SYMBOL(vme_irq_request);

void vme_irq_free(struct vme_dev *vdev, int level, int statid)
{
	struct vme_bridge *bridge;

	bridge = vdev->bridge;
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find VME bus\n");
		return;
	}

	if ((level < 1) || (level > 7)) {
		printk(KERN_ERR "Invalid interrupt level\n");
		return;
	}

	if (bridge->irq_set == NULL) {
		printk(KERN_ERR "Configuring interrupts not supported\n");
		return;
	}

	mutex_lock(&bridge->irq_mtx);

	bridge->irq[level - 1].count--;

	/* Disable IRQ level if no more interrupts attached at this level*/
	if (bridge->irq[level - 1].count == 0)
		bridge->irq_set(bridge, level, 0, 1);

	bridge->irq[level - 1].callback[statid].func = NULL;
	bridge->irq[level - 1].callback[statid].priv_data = NULL;

	mutex_unlock(&bridge->irq_mtx);
}
EXPORT_SYMBOL(vme_irq_free);

int vme_irq_generate(struct vme_dev *vdev, int level, int statid)
{
	struct vme_bridge *bridge;

	bridge = vdev->bridge;
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find VME bus\n");
		return -EINVAL;
	}

	if ((level < 1) || (level > 7)) {
		printk(KERN_WARNING "Invalid interrupt level\n");
		return -EINVAL;
	}

	if (bridge->irq_generate == NULL) {
		printk(KERN_WARNING "Interrupt generation not supported\n");
		return -EINVAL;
	}

	return bridge->irq_generate(bridge, level, statid);
}
EXPORT_SYMBOL(vme_irq_generate);

/*
 * Request the location monitor, return resource or NULL
 */
struct vme_resource *vme_lm_request(struct vme_dev *vdev)
{
	struct vme_bridge *bridge;
	struct list_head *lm_pos = NULL;
	struct vme_lm_resource *allocated_lm = NULL;
	struct vme_lm_resource *lm = NULL;
	struct vme_resource *resource = NULL;

	bridge = vdev->bridge;
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find VME bus\n");
		goto err_bus;
	}

	/* Loop through DMA resources */
	list_for_each(lm_pos, &bridge->lm_resources) {
		lm = list_entry(lm_pos,
			struct vme_lm_resource, list);

		if (lm == NULL) {
			printk(KERN_ERR "Registered NULL Location Monitor resource\n");
			continue;
		}

		/* Find an unlocked controller */
		mutex_lock(&lm->mtx);
		if (lm->locked == 0) {
			lm->locked = 1;
			mutex_unlock(&lm->mtx);
			allocated_lm = lm;
			break;
		}
		mutex_unlock(&lm->mtx);
	}

	/* Check to see if we found a resource */
	if (allocated_lm == NULL)
		goto err_lm;

	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
	if (resource == NULL) {
		printk(KERN_ERR "Unable to allocate resource structure\n");
		goto err_alloc;
	}
	resource->type = VME_LM;
	resource->entry = &allocated_lm->list;

	return resource;

err_alloc:
	/* Unlock image */
	mutex_lock(&lm->mtx);
	lm->locked = 0;
	mutex_unlock(&lm->mtx);
err_lm:
err_bus:
	return NULL;
}
EXPORT_SYMBOL(vme_lm_request);

int vme_lm_count(struct vme_resource *resource)
{
	struct vme_lm_resource *lm;

	if (resource->type != VME_LM) {
		printk(KERN_ERR "Not a Location Monitor resource\n");
		return -EINVAL;
	}

	lm = list_entry(resource->entry, struct vme_lm_resource, list);

	return lm->monitors;
}
EXPORT_SYMBOL(vme_lm_count);

int vme_lm_set(struct vme_resource *resource, unsigned long long lm_base,
	u32 aspace, u32 cycle)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_lm_resource *lm;

	if (resource->type != VME_LM) {
		printk(KERN_ERR "Not a Location Monitor resource\n");
		return -EINVAL;
	}

	lm = list_entry(resource->entry, struct vme_lm_resource, list);

	if (bridge->lm_set == NULL) {
		printk(KERN_ERR "vme_lm_set not supported\n");
		return -EINVAL;
	}

	return bridge->lm_set(lm, lm_base, aspace, cycle);
}
EXPORT_SYMBOL(vme_lm_set);

int vme_lm_get(struct vme_resource *resource, unsigned long long *lm_base,
	u32 *aspace, u32 *cycle)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_lm_resource *lm;

	if (resource->type != VME_LM) {
		printk(KERN_ERR "Not a Location Monitor resource\n");
		return -EINVAL;
	}

	lm = list_entry(resource->entry, struct vme_lm_resource, list);

	if (bridge->lm_get == NULL) {
		printk(KERN_ERR "vme_lm_get not supported\n");
		return -EINVAL;
	}

	return bridge->lm_get(lm, lm_base, aspace, cycle);
}
EXPORT_SYMBOL(vme_lm_get);

int vme_lm_attach(struct vme_resource *resource, int monitor,
	void (*callback)(void *), void *data)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_lm_resource *lm;

	if (resource->type != VME_LM) {
		printk(KERN_ERR "Not a Location Monitor resource\n");
		return -EINVAL;
	}

	lm = list_entry(resource->entry, struct vme_lm_resource, list);

	if (bridge->lm_attach == NULL) {
		printk(KERN_ERR "vme_lm_attach not supported\n");
		return -EINVAL;
	}

	return bridge->lm_attach(lm, monitor, callback, data);
}
EXPORT_SYMBOL(vme_lm_attach);

int vme_lm_detach(struct vme_resource *resource, int monitor)
{
	struct vme_bridge *bridge = find_bridge(resource);
	struct vme_lm_resource *lm;

	if (resource->type != VME_LM) {
		printk(KERN_ERR "Not a Location Monitor resource\n");
		return -EINVAL;
	}

	lm = list_entry(resource->entry, struct vme_lm_resource, list);

	if (bridge->lm_detach == NULL) {
		printk(KERN_ERR "vme_lm_detach not supported\n");
		return -EINVAL;
	}

	return bridge->lm_detach(lm, monitor);
}
EXPORT_SYMBOL(vme_lm_detach);

void vme_lm_free(struct vme_resource *resource)
{
	struct vme_lm_resource *lm;

	if (resource->type != VME_LM) {
		printk(KERN_ERR "Not a Location Monitor resource\n");
		return;
	}

	lm = list_entry(resource->entry, struct vme_lm_resource, list);

	mutex_lock(&lm->mtx);

	/* XXX
	 * Check to see that there aren't any callbacks still attached, if
	 * there are we should probably be detaching them!
	 */

	lm->locked = 0;

	mutex_unlock(&lm->mtx);

	kfree(resource);
}
EXPORT_SYMBOL(vme_lm_free);

int vme_slot_num(struct vme_dev *vdev)
{
	struct vme_bridge *bridge;

	bridge = vdev->bridge;
	if (bridge == NULL) {
		printk(KERN_ERR "Can't find VME bus\n");
		return -EINVAL;
	}

	if (bridge->slot_get == NULL) {
		printk(KERN_WARNING "vme_slot_num not supported\n");
		return -EINVAL;
	}

	return bridge->slot_get(bridge);
}
EXPORT_SYMBOL(vme_slot_num);

int vme_bus_num(struct vme_dev *vdev)
{
	struct vme_bridge *bridge;

	bridge = vdev->bridge;
	if (bridge == NULL) {
		pr_err("Can't find VME bus\n");
		return -EINVAL;
	}

	return bridge->num;
}
EXPORT_SYMBOL(vme_bus_num);

/* - Bridge Registration --------------------------------------------------- */

static void vme_dev_release(struct device *dev)
{
	kfree(dev_to_vme_dev(dev));
}

/* Common bridge initialization */
struct vme_bridge *vme_init_bridge(struct vme_bridge *bridge)
{
	INIT_LIST_HEAD(&bridge->vme_error_handlers);
	INIT_LIST_HEAD(&bridge->master_resources);
	INIT_LIST_HEAD(&bridge->slave_resources);
	INIT_LIST_HEAD(&bridge->dma_resources);
	INIT_LIST_HEAD(&bridge->lm_resources);
	mutex_init(&bridge->irq_mtx);

	return bridge;
}
EXPORT_SYMBOL(vme_init_bridge);

int vme_register_bridge(struct vme_bridge *bridge)
{
	int i;
	int ret = -1;

	mutex_lock(&vme_buses_lock);
	for (i = 0; i < sizeof(vme_bus_numbers) * 8; i++) {
		if ((vme_bus_numbers & (1 << i)) == 0) {
			vme_bus_numbers |= (1 << i);
			bridge->num = i;
			INIT_LIST_HEAD(&bridge->devices);
			list_add_tail(&bridge->bus_list, &vme_bus_list);
			ret = 0;
			break;
		}
	}
	mutex_unlock(&vme_buses_lock);

	return ret;
}
EXPORT_SYMBOL(vme_register_bridge);

void vme_unregister_bridge(struct vme_bridge *bridge)
{
	struct vme_dev *vdev;
	struct vme_dev *tmp;

	mutex_lock(&vme_buses_lock);
	vme_bus_numbers &= ~(1 << bridge->num);
	list_for_each_entry_safe(vdev, tmp, &bridge->devices, bridge_list) {
		list_del(&vdev->drv_list);
		list_del(&vdev->bridge_list);
		device_unregister(&vdev->dev);
	}
	list_del(&bridge->bus_list);
	mutex_unlock(&vme_buses_lock);
}
EXPORT_SYMBOL(vme_unregister_bridge);

/* - Driver Registration --------------------------------------------------- */

static int __vme_register_driver_bus(struct vme_driver *drv,
	struct vme_bridge *bridge, unsigned int ndevs)
{
	int err;
	unsigned int i;
	struct vme_dev *vdev;
	struct vme_dev *tmp;

	for (i = 0; i < ndevs; i++) {
		vdev = kzalloc(sizeof(struct vme_dev), GFP_KERNEL);
		if (!vdev) {
			err = -ENOMEM;
			goto err_devalloc;
		}
		vdev->num = i;
		vdev->bridge = bridge;
		vdev->dev.platform_data = drv;
		vdev->dev.release = vme_dev_release;
		vdev->dev.parent = bridge->parent;
		vdev->dev.bus = &vme_bus_type;
		dev_set_name(&vdev->dev, "%s.%u-%u", drv->name, bridge->num,
			vdev->num);

		err = device_register(&vdev->dev);
		if (err)
			goto err_reg;

		if (vdev->dev.platform_data) {
			list_add_tail(&vdev->drv_list, &drv->devices);
			list_add_tail(&vdev->bridge_list, &bridge->devices);
		} else
			device_unregister(&vdev->dev);
	}
	return 0;

err_reg:
	put_device(&vdev->dev);
	kfree(vdev);
err_devalloc:
	list_for_each_entry_safe(vdev, tmp, &drv->devices, drv_list) {
		list_del(&vdev->drv_list);
		list_del(&vdev->bridge_list);
		device_unregister(&vdev->dev);
	}
	return err;
}

static int __vme_register_driver(struct vme_driver *drv, unsigned int ndevs)
{
	struct vme_bridge *bridge;
	int err = 0;

	mutex_lock(&vme_buses_lock);
	list_for_each_entry(bridge, &vme_bus_list, bus_list) {
		/*
		 * This cannot cause trouble as we already have vme_buses_lock
		 * and if the bridge is removed, it will have to go through
		 * vme_unregister_bridge() to do it (which calls remove() on
		 * the bridge which in turn tries to acquire vme_buses_lock and
		 * will have to wait).
		 */
		err = __vme_register_driver_bus(drv, bridge, ndevs);
		if (err)
			break;
	}
	mutex_unlock(&vme_buses_lock);
	return err;
}

int vme_register_driver(struct vme_driver *drv, unsigned int ndevs)
{
	int err;

	drv->driver.name = drv->name;
	drv->driver.bus = &vme_bus_type;
	INIT_LIST_HEAD(&drv->devices);

	err = driver_register(&drv->driver);
	if (err)
		return err;

	err = __vme_register_driver(drv, ndevs);
	if (err)
		driver_unregister(&drv->driver);

	return err;
}
EXPORT_SYMBOL(vme_register_driver);

void vme_unregister_driver(struct vme_driver *drv)
{
	struct vme_dev *dev, *dev_tmp;

	mutex_lock(&vme_buses_lock);
	list_for_each_entry_safe(dev, dev_tmp, &drv->devices, drv_list) {
		list_del(&dev->drv_list);
		list_del(&dev->bridge_list);
		device_unregister(&dev->dev);
	}
	mutex_unlock(&vme_buses_lock);

	driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(vme_unregister_driver);

/* - Bus Registration ------------------------------------------------------ */

static int vme_bus_match(struct device *dev, struct device_driver *drv)
{
	struct vme_driver *vme_drv;

	vme_drv = container_of(drv, struct vme_driver, driver);

	if (dev->platform_data == vme_drv) {
		struct vme_dev *vdev = dev_to_vme_dev(dev);

		if (vme_drv->match && vme_drv->match(vdev))
			return 1;

		dev->platform_data = NULL;
	}
	return 0;
}

static int vme_bus_probe(struct device *dev)
{
	int retval = -ENODEV;
	struct vme_driver *driver;
	struct vme_dev *vdev = dev_to_vme_dev(dev);

	driver = dev->platform_data;

	if (driver->probe != NULL)
		retval = driver->probe(vdev);

	return retval;
}

static int vme_bus_remove(struct device *dev)
{
	int retval = -ENODEV;
	struct vme_driver *driver;
	struct vme_dev *vdev = dev_to_vme_dev(dev);

	driver = dev->platform_data;

	if (driver->remove != NULL)
		retval = driver->remove(vdev);

	return retval;
}

struct bus_type vme_bus_type = {
	.name = "vme",
	.match = vme_bus_match,
	.probe = vme_bus_probe,
	.remove = vme_bus_remove,
};
EXPORT_SYMBOL(vme_bus_type);

static int __init vme_init(void)
{
	return bus_register(&vme_bus_type);
}
subsys_initcall(vme_init);