path: root/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/module.h>
#include <linux/moduleparam.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 void __exit vme_exit(void);
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);

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

		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);

static 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;
}

/*
 * 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->