diff options
Diffstat (limited to 'drivers/xen/xen-pciback/vpci.c')
| -rw-r--r-- | drivers/xen/xen-pciback/vpci.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/xen/xen-pciback/vpci.c b/drivers/xen/xen-pciback/vpci.c new file mode 100644 index 00000000000..2857ab892f0 --- /dev/null +++ b/drivers/xen/xen-pciback/vpci.c @@ -0,0 +1,244 @@ +/* + * PCI Backend - Provides a Virtual PCI bus (with real devices) + * to the frontend + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/pci.h> +#include <linux/spinlock.h> +#include "pciback.h" + +#define PCI_SLOT_MAX 32 + +struct vpci_dev_data { + /* Access to dev_list must be protected by lock */ + struct list_head dev_list[PCI_SLOT_MAX]; + spinlock_t lock; +}; + +static inline struct list_head *list_first(struct list_head *head) +{ + return head->next; +} + +struct pci_dev *pciback_get_pci_dev(struct pciback_device *pdev, + unsigned int domain, unsigned int bus, + unsigned int devfn) +{ + struct pci_dev_entry *entry; + struct pci_dev *dev = NULL; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + unsigned long flags; + + if (domain != 0 || bus != 0) + return NULL; + + if (PCI_SLOT(devfn) < PCI_SLOT_MAX) { + spin_lock_irqsave(&vpci_dev->lock, flags); + + list_for_each_entry(entry, + &vpci_dev->dev_list[PCI_SLOT(devfn)], + list) { + if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) { + dev = entry->dev; + break; + } + } + + spin_unlock_irqrestore(&vpci_dev->lock, flags); + } + return dev; +} + +static inline int match_slot(struct pci_dev *l, struct pci_dev *r) +{ + if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus) + && l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn)) + return 1; + + return 0; +} + +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, func = -1; + struct pci_dev_entry *t, *dev_entry; + struct vpci_dev_data *vpci_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; + } + + dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL); + if (!dev_entry) { + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "Error adding entry to virtual PCI bus"); + goto out; + } + + dev_entry->dev = dev; + + spin_lock_irqsave(&vpci_dev->lock, flags); + + /* Keep multi-function devices together on the virtual PCI bus */ + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + if (!list_empty(&vpci_dev->dev_list[slot])) { + t = list_entry(list_first(&vpci_dev->dev_list[slot]), + struct pci_dev_entry, list); + + if (match_slot(dev, t->dev)) { + pr_info("pciback: vpci: %s: " + "assign to virtual slot %d func %d\n", + pci_name(dev), slot, + PCI_FUNC(dev->devfn)); + list_add_tail(&dev_entry->list, + &vpci_dev->dev_list[slot]); + func = PCI_FUNC(dev->devfn); + goto unlock; + } + } + } + + /* Assign to a new slot on the virtual PCI bus */ + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + if (list_empty(&vpci_dev->dev_list[slot])) { + printk(KERN_INFO + "pciback: vpci: %s: assign to virtual slot %d\n", + pci_name(dev), slot); + list_add_tail(&dev_entry->list, + &vpci_dev->dev_list[slot]); + func = PCI_FUNC(dev->devfn); + goto unlock; + } + } + + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "No more space on root virtual PCI bus"); + +unlock: + spin_unlock_irqrestore(&vpci_dev->lock, flags); + + /* Publish this device. */ + if (!err) + err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid); + +out: + return err; +} + +void pciback_release_pci_dev(struct pciback_device *pdev, struct pci_dev *dev) +{ + int slot; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + struct pci_dev *found_dev = NULL; + unsigned long flags; + + spin_lock_irqsave(&vpci_dev->lock, flags); + + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + struct pci_dev_entry *e, *tmp; + list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot], + list) { + if (e->dev == dev) { + list_del(&e->list); + found_dev = e->dev; + kfree(e); + goto out; + } + } + } + +out: + spin_unlock_irqrestore(&vpci_dev->lock, flags); + + if (found_dev) + pcistub_put_pci_dev(found_dev); +} + +int pciback_init_devices(struct pciback_device *pdev) +{ + int slot; + struct vpci_dev_data *vpci_dev; + + vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL); + if (!vpci_dev) + return -ENOMEM; + + spin_lock_init(&vpci_dev->lock); + + for (slot = 0; slot < PCI_SLOT_MAX; slot++) + INIT_LIST_HEAD(&vpci_dev->dev_list[slot]); + + pdev->pci_dev_data = vpci_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; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + struct pci_dev_entry *e, *tmp; + list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot], + list) { + list_del(&e->list); + pcistub_put_pci_dev(e->dev); + kfree(e); + } + } + + kfree(vpci_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) +{ + struct pci_dev_entry *entry; + struct pci_dev *dev = NULL; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + unsigned long flags; + int found = 0, slot; + + spin_lock_irqsave(&vpci_dev->lock, flags); + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + list_for_each_entry(entry, + &vpci_dev->dev_list[slot], + list) { + dev = entry->dev; + if (dev && dev->bus->number == pcidev->bus->number + && pci_domain_nr(dev->bus) == + pci_domain_nr(pcidev->bus) + && dev->devfn == pcidev->devfn) { + found = 1; + *domain = 0; + *bus = 0; + *devfn = PCI_DEVFN(slot, + PCI_FUNC(pcidev->devfn)); + } + } + } + spin_unlock_irqrestore(&vpci_dev->lock, flags); + return found; +} |