vme.c

Go to the documentation of this file.

/*
 * VME Bridge Framework
 *
 * Author: Martyn Welch <[email protected]>
 * 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:
        /*
         * Any value held in an unsigned long long can be used as the
         * base
         */
        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->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 "vme_master_set not supported\n");
        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);

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);

    return 0;
}
EXPORT_SYMBOL(vme_dma_free);

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 "Spurilous 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)(int))
{
    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);
}
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_get(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_get not supported\n");
        return -EINVAL;
    }

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


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

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

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:
    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);
}

static void __exit vme_exit(void)
{
    bus_unregister(&vme_bus_type);
}

MODULE_DESCRIPTION("VME bridge driver framework");
MODULE_AUTHOR("Martyn Welch <[email protected]");
MODULE_LICENSE("GPL");

module_init(vme_init);
module_exit(vme_exit);