+/****************************************************************************
+ *
+ * The following functions initialize the MSI interrupts for all IOMMUs
+ * in the system. Its a bit challenging because there could be multiple
+ * IOMMUs per PCI BDF but we can call pci_enable_msi(x) only once per
+ * pci_dev.
+ *
+ ****************************************************************************/
+
+static int __init iommu_setup_msix(struct amd_iommu *iommu)
+{
+ struct amd_iommu *curr;
+ struct msix_entry entries[32]; /* only 32 supported by AMD IOMMU */
+ int nvec = 0, i;
+
+ list_for_each_entry(curr, &amd_iommu_list, list) {
+ if (curr->dev == iommu->dev) {
+ entries[nvec].entry = curr->evt_msi_num;
+ entries[nvec].vector = 0;
+ curr->int_enabled = true;
+ nvec++;
+ }
+ }
+
+ if (pci_enable_msix(iommu->dev, entries, nvec)) {
+ pci_disable_msix(iommu->dev);
+ return 1;
+ }
+
+ for (i = 0; i < nvec; ++i) {
+ int r = request_irq(entries->vector, amd_iommu_int_handler,
+ IRQF_SAMPLE_RANDOM,
+ "AMD IOMMU",
+ NULL);
+ if (r)
+ goto out_free;
+ }
+
+ return 0;
+
+out_free:
+ for (i -= 1; i >= 0; --i)
+ free_irq(entries->vector, NULL);
+
+ pci_disable_msix(iommu->dev);
+
+ return 1;
+}
+
+static int __init iommu_setup_msi(struct amd_iommu *iommu)
+{
+ int r;
+ struct amd_iommu *curr;
+
+ list_for_each_entry(curr, &amd_iommu_list, list) {
+ if (curr->dev == iommu->dev)
+ curr->int_enabled = true;
+ }
+
+
+ if (pci_enable_msi(iommu->dev))
+ return 1;
+
+ r = request_irq(iommu->dev->irq, amd_iommu_int_handler,
+ IRQF_SAMPLE_RANDOM,
+ "AMD IOMMU",
+ NULL);
+
+ if (r) {
+ pci_disable_msi(iommu->dev);
+ return 1;
+ }
+
+ return 0;
+}
+
+static int __init iommu_init_msi(struct amd_iommu *iommu)
+{
+ if (iommu->int_enabled)
+ return 0;
+
+ if (pci_find_capability(iommu->dev, PCI_CAP_ID_MSIX))
+ return iommu_setup_msix(iommu);
+ else if (pci_find_capability(iommu->dev, PCI_CAP_ID_MSI))
+ return iommu_setup_msi(iommu);
+
+ return 1;
+}
+