blob: 5386bebf7f9a22c6823b427952ca1a7c3b36b042 [file] [log] [blame]
/*
* PCI Backend - Provides restricted access to the real PCI bus topology
* to the frontend
*
* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
*/
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#include "pciback.h"
struct passthrough_dev_data {
/* Access to dev_list must be protected by lock */
struct list_head dev_list;
spinlock_t lock;
};
struct pci_dev *pciback_get_pci_dev(struct pciback_device *pdev,
unsigned int domain, unsigned int bus,
unsigned int devfn)
{
struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
struct pci_dev_entry *dev_entry;
struct pci_dev *dev = NULL;
unsigned long flags;
spin_lock_irqsave(&dev_data->lock, flags);
list_for_each_entry(dev_entry, &dev_data->dev_list, list) {
if (domain == (unsigned int)pci_domain_nr(dev_entry->dev->bus)
&& bus == (unsigned int)dev_entry->dev->bus->number
&& devfn == dev_entry->dev->devfn) {
dev = dev_entry->dev;
break;
}
}
spin_unlock_irqrestore(&dev_data->lock, flags);
return dev;
}
int pciback_add_pci_dev(struct pciback_device *pdev, struct pci_dev *dev,
int devid, publish_pci_dev_cb publish_cb)
{
struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
struct pci_dev_entry *dev_entry;
unsigned long flags;
unsigned int domain, bus, devfn;
int err;
dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
if (!dev_entry)
return -ENOMEM;
dev_entry->dev = dev;
spin_lock_irqsave(&dev_data->lock, flags);
list_add_tail(&dev_entry->list, &dev_data->dev_list);
spin_unlock_irqrestore(&dev_data->lock, flags);
/* Publish this device. */
domain = (unsigned int)pci_domain_nr(dev->bus);
bus = (unsigned int)dev->bus->number;
devfn = dev->devfn;
err = publish_cb(pdev, domain, bus, devfn, devid);
return err;
}
void pciback_release_pci_dev(struct pciback_device *pdev, struct pci_dev *dev)
{
struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
struct pci_dev_entry *dev_entry, *t;
struct pci_dev *found_dev = NULL;
unsigned long flags;
spin_lock_irqsave(&dev_data->lock, flags);
list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) {
if (dev_entry->dev == dev) {
list_del(&dev_entry->list);
found_dev = dev_entry->dev;
kfree(dev_entry);
}
}
spin_unlock_irqrestore(&dev_data->lock, flags);
if (found_dev)
pcistub_put_pci_dev(found_dev);
}
int pciback_init_devices(struct pciback_device *pdev)
{
struct passthrough_dev_data *dev_data;
dev_data = kmalloc(sizeof(*dev_data), GFP_KERNEL);
if (!dev_data)
return -ENOMEM;
spin_lock_init(&dev_data->lock);
INIT_LIST_HEAD(&dev_data->dev_list);
pdev->pci_dev_data = dev_data;
return 0;
}
int pciback_publish_pci_roots(struct pciback_device *pdev,
publish_pci_root_cb publish_root_cb)
{
int err = 0;
struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
struct pci_dev_entry *dev_entry, *e;
struct pci_dev *dev;
int found;
unsigned int domain, bus;
spin_lock(&dev_data->lock);
list_for_each_entry(dev_entry, &dev_data->dev_list, list) {
/* Only publish this device as a root if none of its
* parent bridges are exported
*/
found = 0;
dev = dev_entry->dev->bus->self;
for (; !found && dev != NULL; dev = dev->bus->self) {
list_for_each_entry(e, &dev_data->dev_list, list) {
if (dev == e->dev) {
found = 1;
break;
}
}
}
domain = (unsigned int)pci_domain_nr(dev_entry->dev->bus);
bus = (unsigned int)dev_entry->dev->bus->number;
if (!found) {
err = publish_root_cb(pdev, domain, bus);
if (err)
break;
}
}
spin_unlock(&dev_data->lock);
return err;
}
void pciback_release_devices(struct pciback_device *pdev)
{
struct passthrough_dev_data *dev_data = pdev->pci_dev_data;
struct pci_dev_entry *dev_entry, *t;
list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) {
list_del(&dev_entry->list);
pcistub_put_pci_dev(dev_entry->dev);
kfree(dev_entry);
}
kfree(dev_data);
pdev->pci_dev_data = NULL;
}
int pciback_get_pcifront_dev(struct pci_dev *pcidev,
struct pciback_device *pdev,
unsigned int *domain, unsigned int *bus,
unsigned int *devfn)
{
*domain = pci_domain_nr(pcidev->bus);
*bus = pcidev->bus->number;
*devfn = pcidev->devfn;
return 1;
}