mirror of
https://github.com/torvalds/linux
synced 2024-10-27 05:39:25 +00:00
192 lines
4.5 KiB
C
192 lines
4.5 KiB
C
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/*
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* PCI Backend - Provides a Virtual PCI bus (with real devices)
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* to the frontend
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*
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* Author: Ryan Wilson <hap9@epoch.ncsc.mil> (vpci.c)
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* Author: Tristan Gingold <tristan.gingold@bull.net>, from vpci.c
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*/
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <linux/pci.h>
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#include <linux/spinlock.h>
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#include "pciback.h"
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/* There are at most 32 slots in a pci bus. */
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#define PCI_SLOT_MAX 32
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#define PCI_BUS_NBR 2
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struct slot_dev_data {
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/* Access to dev_list must be protected by lock */
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struct pci_dev *slots[PCI_BUS_NBR][PCI_SLOT_MAX];
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spinlock_t lock;
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};
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struct pci_dev *pciback_get_pci_dev(struct pciback_device *pdev,
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unsigned int domain, unsigned int bus,
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unsigned int devfn)
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{
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struct pci_dev *dev = NULL;
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struct slot_dev_data *slot_dev = pdev->pci_dev_data;
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unsigned long flags;
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if (domain != 0 || PCI_FUNC(devfn) != 0)
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return NULL;
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if (PCI_SLOT(devfn) >= PCI_SLOT_MAX || bus >= PCI_BUS_NBR)
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return NULL;
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spin_lock_irqsave(&slot_dev->lock, flags);
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dev = slot_dev->slots[bus][PCI_SLOT(devfn)];
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spin_unlock_irqrestore(&slot_dev->lock, flags);
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return dev;
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}
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int pciback_add_pci_dev(struct pciback_device *pdev, struct pci_dev *dev,
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int devid, publish_pci_dev_cb publish_cb)
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{
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int err = 0, slot, bus;
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struct slot_dev_data *slot_dev = pdev->pci_dev_data;
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unsigned long flags;
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if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
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err = -EFAULT;
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xenbus_dev_fatal(pdev->xdev, err,
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"Can't export bridges on the virtual PCI bus");
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goto out;
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}
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spin_lock_irqsave(&slot_dev->lock, flags);
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/* Assign to a new slot on the virtual PCI bus */
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for (bus = 0; bus < PCI_BUS_NBR; bus++)
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for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
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if (slot_dev->slots[bus][slot] == NULL) {
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printk(KERN_INFO
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"pciback: slot: %s: assign to virtual "
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"slot %d, bus %d\n",
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pci_name(dev), slot, bus);
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slot_dev->slots[bus][slot] = dev;
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goto unlock;
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}
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}
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err = -ENOMEM;
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xenbus_dev_fatal(pdev->xdev, err,
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"No more space on root virtual PCI bus");
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unlock:
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spin_unlock_irqrestore(&slot_dev->lock, flags);
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/* Publish this device. */
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if (!err)
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err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, 0), devid);
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out:
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return err;
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}
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void pciback_release_pci_dev(struct pciback_device *pdev, struct pci_dev *dev)
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{
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int slot, bus;
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struct slot_dev_data *slot_dev = pdev->pci_dev_data;
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struct pci_dev *found_dev = NULL;
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unsigned long flags;
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spin_lock_irqsave(&slot_dev->lock, flags);
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for (bus = 0; bus < PCI_BUS_NBR; bus++)
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for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
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if (slot_dev->slots[bus][slot] == dev) {
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slot_dev->slots[bus][slot] = NULL;
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found_dev = dev;
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goto out;
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}
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}
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out:
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spin_unlock_irqrestore(&slot_dev->lock, flags);
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if (found_dev)
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pcistub_put_pci_dev(found_dev);
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}
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int pciback_init_devices(struct pciback_device *pdev)
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{
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int slot, bus;
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struct slot_dev_data *slot_dev;
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slot_dev = kmalloc(sizeof(*slot_dev), GFP_KERNEL);
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if (!slot_dev)
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return -ENOMEM;
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spin_lock_init(&slot_dev->lock);
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for (bus = 0; bus < PCI_BUS_NBR; bus++)
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for (slot = 0; slot < PCI_SLOT_MAX; slot++)
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slot_dev->slots[bus][slot] = NULL;
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pdev->pci_dev_data = slot_dev;
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return 0;
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}
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int pciback_publish_pci_roots(struct pciback_device *pdev,
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publish_pci_root_cb publish_cb)
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{
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/* The Virtual PCI bus has only one root */
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return publish_cb(pdev, 0, 0);
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}
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void pciback_release_devices(struct pciback_device *pdev)
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{
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int slot, bus;
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struct slot_dev_data *slot_dev = pdev->pci_dev_data;
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struct pci_dev *dev;
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for (bus = 0; bus < PCI_BUS_NBR; bus++)
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for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
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dev = slot_dev->slots[bus][slot];
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if (dev != NULL)
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pcistub_put_pci_dev(dev);
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}
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kfree(slot_dev);
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pdev->pci_dev_data = NULL;
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}
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int pciback_get_pcifront_dev(struct pci_dev *pcidev,
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struct pciback_device *pdev,
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unsigned int *domain, unsigned int *bus,
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unsigned int *devfn)
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{
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int slot, busnr;
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struct slot_dev_data *slot_dev = pdev->pci_dev_data;
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struct pci_dev *dev;
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int found = 0;
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unsigned long flags;
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spin_lock_irqsave(&slot_dev->lock, flags);
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for (busnr = 0; busnr < PCI_BUS_NBR; bus++)
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for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
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dev = slot_dev->slots[busnr][slot];
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if (dev && dev->bus->number == pcidev->bus->number
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&& dev->devfn == pcidev->devfn
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&& pci_domain_nr(dev->bus) ==
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pci_domain_nr(pcidev->bus)) {
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found = 1;
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*domain = 0;
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*bus = busnr;
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*devfn = PCI_DEVFN(slot, 0);
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goto out;
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}
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}
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out:
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spin_unlock_irqrestore(&slot_dev->lock, flags);
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return found;
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}
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