xen/pciback: Check PF instead of VF for PCI_COMMAND_MEMORY

[pandora-kernel.git] / drivers / xen / xen-pciback / pciback_ops.c

diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index b9e2bb9..6e1b06b 100644 (file)
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -68,6 +68,13 @@ static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
                enable ? "enable" : "disable");
 
        if (enable) {
+               /*
+                * The MSI or MSI-X should not have an IRQ handler. Otherwise
+                * if the guest terminates we BUG_ON in free_msi_irqs.
+                */
+               if (dev->msi_enabled || dev->msix_enabled)
+                       goto out;
+
                rc = request_irq(dev_data->irq,
                                xen_pcibk_guest_interrupt, IRQF_SHARED,
                                dev_data->irq_name, dev);
@@ -176,20 +183,23 @@ static
 int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
                          struct pci_dev *dev, struct xen_pci_op *op)
 {
-       struct xen_pcibk_dev_data *dev_data;
-
        if (unlikely(verbose_request))
                printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
                       pci_name(dev));
-       pci_disable_msi(dev);
 
+       if (dev->msi_enabled) {
+               struct xen_pcibk_dev_data *dev_data;
+
+               pci_disable_msi(dev);
+
+               dev_data = pci_get_drvdata(dev);
+               if (dev_data)
+                       dev_data->ack_intr = 1;
+       }
        op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
        if (unlikely(verbose_request))
                printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
                        op->value);
-       dev_data = pci_get_drvdata(dev);
-       if (dev_data)
-               dev_data->ack_intr = 1;
        return 0;
 }
 
@@ -200,6 +210,7 @@ int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
        struct xen_pcibk_dev_data *dev_data;
        int i, result;
        struct msix_entry *entries;
+       u16 cmd;
 
        if (unlikely(verbose_request))
                printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
@@ -211,7 +222,13 @@ int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
        if (dev->msix_enabled)
                return -EALREADY;
 
-       if (dev->msi_enabled)
+       /*
+        * PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able
+        * to access the BARs where the MSI-X entries reside.
+        * But VF devices are unique in which the PF needs to be checked.
+        */
+       pci_read_config_word(pci_physfn(dev), PCI_COMMAND, &cmd);
+       if (dev->msi_enabled || !(cmd & PCI_COMMAND_MEMORY))
                return -ENXIO;
 
        entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
@@ -255,23 +272,27 @@ static
 int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
                           struct pci_dev *dev, struct xen_pci_op *op)
 {
-       struct xen_pcibk_dev_data *dev_data;
        if (unlikely(verbose_request))
                printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
                        pci_name(dev));
-       pci_disable_msix(dev);
 
+       if (dev->msix_enabled) {
+               struct xen_pcibk_dev_data *dev_data;
+
+               pci_disable_msix(dev);
+
+               dev_data = pci_get_drvdata(dev);
+               if (dev_data)
+                       dev_data->ack_intr = 1;
+       }
        /*
         * SR-IOV devices (which don't have any legacy IRQ) have
         * an undefined IRQ value of zero.
         */
        op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
        if (unlikely(verbose_request))
-               printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
-                       op->value);
-       dev_data = pci_get_drvdata(dev);
-       if (dev_data)
-               dev_data->ack_intr = 1;
+               printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n",
+                      pci_name(dev), op->value);
        return 0;
 }
 #endif