iommu/amd: Implement MSI routines for interrupt remapping

Add routines to setup interrupt remapping for MSI
interrupts.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

drivers/iommu/amd_iommu.c

@@ -4126,4 +4126,78 @@ static int free_irq(int irq)
 	return 0;
 }
 
+static void compose_msi_msg(struct pci_dev *pdev,
+			    unsigned int irq, unsigned int dest,
+			    struct msi_msg *msg, u8 hpet_id)
+{
+	struct irq_2_iommu *irte_info;
+	struct irq_cfg *cfg;
+	union irte irte;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return;
+
+	irte_info = &cfg->irq_2_iommu;
+
+	irte.val		= 0;
+	irte.fields.vector	= cfg->vector;
+	irte.fields.int_type    = apic->irq_delivery_mode;
+	irte.fields.destination	= dest;
+	irte.fields.dm		= apic->irq_dest_mode;
+	irte.fields.valid	= 1;
+
+	modify_irte(irte_info->sub_handle, irte_info->irte_index, irte);
+
+	msg->address_hi = MSI_ADDR_BASE_HI;
+	msg->address_lo = MSI_ADDR_BASE_LO;
+	msg->data       = irte_info->irte_index;
+}
+
+static int msi_alloc_irq(struct pci_dev *pdev, int irq, int nvec)
+{
+	struct irq_cfg *cfg;
+	int index;
+	u16 devid;
+
+	if (!pdev)
+		return -EINVAL;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return -EINVAL;
+
+	devid = get_device_id(&pdev->dev);
+	index = alloc_irq_index(cfg, devid, nvec);
+
+	return index < 0 ? MAX_IRQS_PER_TABLE : index;
+}
+
+static int msi_setup_irq(struct pci_dev *pdev, unsigned int irq,
+			 int index, int offset)
+{
+	struct irq_2_iommu *irte_info;
+	struct irq_cfg *cfg;
+	u16 devid;
+
+	if (!pdev)
+		return -EINVAL;
+
+	cfg = irq_get_chip_data(irq);
+	if (!cfg)
+		return -EINVAL;
+
+	if (index >= MAX_IRQS_PER_TABLE)
+		return 0;
+
+	devid		= get_device_id(&pdev->dev);
+	irte_info	= &cfg->irq_2_iommu;
+
+	irte_info->sub_handle = devid;
+	irte_info->irte_index = index + offset;
+	irte_info->iommu      = (void *)cfg;
+
+	return 0;
+}
+
 #endif