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/*
* PCI Backend - Provides a Virtual PCI bus (with real devices)
* to the frontend
*
* Author: Ryan Wilson <hap9@epoch.ncsc.mil> (vpci.c)
* Author: Tristan Gingold <tristan.gingold@bull.net>, from vpci.c
*/
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#include "pciback.h"
/* There are at most 32 slots in a pci bus. */
#define PCI_SLOT_MAX 32
#define PCI_BUS_NBR 2
struct slot_dev_data {
/* Access to dev_list must be protected by lock */
struct pci_dev *slots[PCI_BUS_NBR][PCI_SLOT_MAX];
spinlock_t lock;
};
struct pci_dev *pciback_get_pci_dev(struct pciback_device *pdev,
unsigned int domain, unsigned int bus,
unsigned int devfn)
{
struct pci_dev *dev = NULL;
struct slot_dev_data *slot_dev = pdev->pci_dev_data;
unsigned long flags;
if (domain != 0 || PCI_FUNC(devfn) != 0)
return NULL;
if (PCI_SLOT(devfn) >= PCI_SLOT_MAX || bus >= PCI_BUS_NBR)
return NULL;
spin_lock_irqsave(&slot_dev->lock, flags);
dev = slot_dev->slots[bus][PCI_SLOT(devfn)];
spin_unlock_irqrestore(&slot_dev->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)
{
int err = 0, slot, bus;
struct slot_dev_data *slot_dev = pdev->pci_dev_data;
unsigned long flags;
if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
err = -EFAULT;
xenbus_dev_fatal(pdev->xdev, err,
"Can't export bridges on the virtual PCI bus");
goto out;
}
spin_lock_irqsave(&slot_dev->lock, flags);
/* Assign to a new slot on the virtual PCI bus */
for (bus = 0; bus < PCI_BUS_NBR; bus++)
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
if (slot_dev->slots[bus][slot] == NULL) {
printk(KERN_INFO
"pciback: slot: %s: assign to virtual "
"slot %d, bus %d\n",
pci_name(dev), slot, bus);
slot_dev->slots[bus][slot] = dev;
goto unlock;
}
}
err = -ENOMEM;
xenbus_dev_fatal(pdev->xdev, err,
"No more space on root virtual PCI bus");
unlock:
spin_unlock_irqrestore(&slot_dev->lock, flags);
/* Publish this device. */
if (!err)
err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, 0), devid);
out:
return err;
}
void pciback_release_pci_dev(struct pciback_device *pdev, struct pci_dev *dev)
{
int slot, bus;
struct slot_dev_data *slot_dev = pdev->pci_dev_data;
struct pci_dev *found_dev = NULL;
unsigned long flags;
spin_lock_irqsave(&slot_dev->lock, flags);
for (bus = 0; bus < PCI_BUS_NBR; bus++)
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
if (slot_dev->slots[bus][slot] == dev) {
slot_dev->slots[bus][slot] = NULL;
found_dev = dev;
goto out;
}
}
out:
spin_unlock_irqrestore(&slot_dev->lock, flags);
if (found_dev)
pcistub_put_pci_dev(found_dev);
}
int pciback_init_devices(struct pciback_device *pdev)
{
int slot, bus;
struct slot_dev_data *slot_dev;
slot_dev = kmalloc(sizeof(*slot_dev), GFP_KERNEL);
if (!slot_dev)
return -ENOMEM;
spin_lock_init(&slot_dev->lock);
for (bus = 0; bus < PCI_BUS_NBR; bus++)
for (slot = 0; slot < PCI_SLOT_MAX; slot++)
slot_dev->slots[bus][slot] = NULL;
pdev->pci_dev_data = slot_dev;
return 0;
}
int pciback_publish_pci_roots(struct pciback_device *pdev,
publish_pci_root_cb publish_cb)
{
/* The Virtual PCI bus has only one root */
return publish_cb(pdev, 0, 0);
}
void pciback_release_devices(struct pciback_device *pdev)
{
int slot, bus;
struct slot_dev_data *slot_dev = pdev->pci_dev_data;
struct pci_dev *dev;
for (bus = 0; bus < PCI_BUS_NBR; bus++)
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
dev = slot_dev->slots[bus][slot];
if (dev != NULL)
pcistub_put_pci_dev(dev);
}
kfree(slot_dev);
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)
{
int slot, busnr;
struct slot_dev_data *slot_dev = pdev->pci_dev_data;
struct pci_dev *dev;
int found = 0;
unsigned long flags;
spin_lock_irqsave(&slot_dev->lock, flags);
for (busnr = 0; busnr < PCI_BUS_NBR; bus++)
for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
dev = slot_dev->slots[busnr][slot];
if (dev && dev->bus->number == pcidev->bus->number
&& dev->devfn == pcidev->devfn
&& pci_domain_nr(dev->bus) ==
pci_domain_nr(pcidev->bus)) {
found = 1;
*domain = 0;
*bus = busnr;
*devfn = PCI_DEVFN(slot, 0);
goto out;
}
}
out:
spin_unlock_irqrestore(&slot_dev->lock, flags);
return found;
}
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