PCI/P2PDMA: Refactor pci_p2pdma_map_type()

All callers of pci_p2pdma_map_type() have a struct dev_pgmap and a struct
device (of the client doing the DMA transfer). Thus move the conversion to
struct pci_devs for the provider and client into this function.

Link: https://lore.kernel.org/r/20210610160609.28447-6-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index c07c928..0bb6792 100644 (file)
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -816,12 +816,20 @@ void pci_p2pmem_publish(struct pci_dev *pdev, bool publish)
 }
 EXPORT_SYMBOL_GPL(pci_p2pmem_publish);
 
-static enum pci_p2pdma_map_type pci_p2pdma_map_type(struct pci_dev *provider,
-                                                   struct pci_dev *client)
+static enum pci_p2pdma_map_type pci_p2pdma_map_type(struct dev_pagemap *pgmap,
+                                                   struct device *dev)
 {
+       struct pci_dev *provider = to_p2p_pgmap(pgmap)->provider;
+       struct pci_dev *client;
+
        if (!provider->p2pdma)
                return PCI_P2PDMA_MAP_NOT_SUPPORTED;
 
+       if (!dev_is_pci(dev))
+               return PCI_P2PDMA_MAP_NOT_SUPPORTED;
+
+       client = to_pci_dev(dev);
+
        return xa_to_value(xa_load(&provider->p2pdma->map_types,
                                   map_types_idx(client)));
 }
@@ -858,14 +866,8 @@ int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
 {
        struct pci_p2pdma_pagemap *p2p_pgmap =
                to_p2p_pgmap(sg_page(sg)->pgmap);
-       struct pci_dev *client;
-
-       if (WARN_ON_ONCE(!dev_is_pci(dev)))
-               return 0;
 
-       client = to_pci_dev(dev);
-
-       switch (pci_p2pdma_map_type(p2p_pgmap->provider, client)) {
+       switch (pci_p2pdma_map_type(sg_page(sg)->pgmap, dev)) {
        case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE:
                return dma_map_sg_attrs(dev, sg, nents, dir, attrs);
        case PCI_P2PDMA_MAP_BUS_ADDR:
@@ -889,17 +891,9 @@ EXPORT_SYMBOL_GPL(pci_p2pdma_map_sg_attrs);
 void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
                int nents, enum dma_data_direction dir, unsigned long attrs)
 {
-       struct pci_p2pdma_pagemap *p2p_pgmap =
-               to_p2p_pgmap(sg_page(sg)->pgmap);
        enum pci_p2pdma_map_type map_type;
-       struct pci_dev *client;
-
-       if (WARN_ON_ONCE(!dev_is_pci(dev)))
-               return;
-
-       client = to_pci_dev(dev);
 
-       map_type = pci_p2pdma_map_type(p2p_pgmap->provider, client);
+       map_type = pci_p2pdma_map_type(sg_page(sg)->pgmap, dev);
 
        if (map_type == PCI_P2PDMA_MAP_THRU_HOST_BRIDGE)
                dma_unmap_sg_attrs(dev, sg, nents, dir, attrs);