PCI/P2PDMA: Add provider's pci_dev to pci_p2pdma_pagemap struct

The provider will be needed to figure out how to map a device.

Link: https://lore.kernel.org/r/20190730163545.4915-3-logang@deltatee.com
Link: https://lore.kernel.org/r/20190812173048.9186-3-logang@deltatee.comSigned-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

drivers/pci/p2pdma.c

@@ -27,6 +27,7 @@ struct pci_p2pdma {
 
 struct pci_p2pdma_pagemap {
 	struct dev_pagemap pgmap;
+	struct pci_dev *provider;
 	u64 bus_offset;
 };
 
@@ -178,6 +179,7 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
 	pgmap->res.flags = pci_resource_flags(pdev, bar);
 	pgmap->type = MEMORY_DEVICE_PCI_P2PDMA;
 
+	p2p_pgmap->provider = pdev;
 	p2p_pgmap->bus_offset = pci_bus_address(pdev, bar) -
 		pci_resource_start(pdev, bar);