PCI: dwc: Free MSI IRQ page in dw_pcie_free_msi()

To avoid a memory leak, free the page allocated for MSI IRQ in
dw_pcie_free_msi().
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>

drivers/pci/controller/dwc/pcie-designware-host.c

@@ -305,20 +305,24 @@ void dw_pcie_free_msi(struct pcie_port *pp)
 
 	irq_domain_remove(pp->msi_domain);
 	irq_domain_remove(pp->irq_domain);
+
+	if (pp->msi_page)
+		__free_page(pp->msi_page);
 }
 
 void dw_pcie_msi_init(struct pcie_port *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct device *dev = pci->dev;
-	struct page *page;
 	u64 msi_target;
 
-	page = alloc_page(GFP_KERNEL);
-	pp->msi_data = dma_map_page(dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
+	pp->msi_page = alloc_page(GFP_KERNEL);
+	pp->msi_data = dma_map_page(dev, pp->msi_page, 0, PAGE_SIZE,
+				    DMA_FROM_DEVICE);
 	if (dma_mapping_error(dev, pp->msi_data)) {
 		dev_err(dev, "Failed to map MSI data\n");
-		__free_page(page);
+		__free_page(pp->msi_page);
+		pp->msi_page = NULL;
 		return;
 	}
 	msi_target = (u64)pp->msi_data;

drivers/pci/controller/dwc/pcie-designware.h

@@ -179,6 +179,7 @@ struct pcie_port {
 	struct irq_domain	*irq_domain;
 	struct irq_domain	*msi_domain;
 	dma_addr_t		msi_data;
+	struct page		*msi_page;
 	u32			num_vectors;
 	u32			irq_mask[MAX_MSI_CTRLS];
 	raw_spinlock_t		lock;