diff options
Diffstat (limited to 'drivers/xen/xen-pciback/slot.c')
| -rw-r--r-- | drivers/xen/xen-pciback/slot.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/drivers/xen/xen-pciback/slot.c b/drivers/xen/xen-pciback/slot.c new file mode 100644 index 000000000000..efb922d6f78e --- /dev/null +++ b/drivers/xen/xen-pciback/slot.c @@ -0,0 +1,191 @@ +/* + * 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; + +} |