PCI: Add dma_ranges window list

Add a dma_ranges field in PCI host bridge structure to hold resource
entries list of memory regions in sorted order representing memory ranges
that can be accessed through DMA transactions.
Based-on-a-patch-by: NOza Pawandeep <oza.oza@broadcom.com>
Signed-off-by: NSrinath Mannam <srinath.mannam@broadcom.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NOza Pawandeep <poza@codeaurora.org>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

drivers/pci/probe.c

@@ -595,6 +595,7 @@ struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
 		return NULL;
 
 	INIT_LIST_HEAD(&bridge->windows);
+	INIT_LIST_HEAD(&bridge->dma_ranges);
 	bridge->dev.release = pci_release_host_bridge_dev;
 
 	/*
@@ -623,6 +624,7 @@ struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev,
 		return NULL;
 
 	INIT_LIST_HEAD(&bridge->windows);
+	INIT_LIST_HEAD(&bridge->dma_ranges);
 	bridge->dev.release = devm_pci_release_host_bridge_dev;
 
 	return bridge;
@@ -632,6 +634,7 @@ EXPORT_SYMBOL(devm_pci_alloc_host_bridge);
 void pci_free_host_bridge(struct pci_host_bridge *bridge)
 {
 	pci_free_resource_list(&bridge->windows);
+	pci_free_resource_list(&bridge->dma_ranges);
 
 	kfree(bridge);
 }

include/linux/pci.h

@@ -490,6 +490,7 @@ struct pci_host_bridge {
 	void		*sysdata;
 	int		busnr;
 	struct list_head windows;	/* resource_entry */
+	struct list_head dma_ranges;	/* dma ranges resource list */
 	u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */
 	int (*map_irq)(const struct pci_dev *, u8, u8);
 	void (*release_fn)(struct pci_host_bridge *);