[PATCH v2 01/14] PCI/P2PDMA: Introduce private pagemap structure

[Logan Gunthorpe]

Move the PCI bus offset from the generic dev_pagemap structure to a
specific pci_p2pdma_pagemap structure.

This structure will grow in subsequent patches.

Signed-off-by: Logan Gunthorpe <log...@deltatee.com>
---
 drivers/pci/p2pdma.c     | 26 ++++++++++++++++++++------
 include/linux/memremap.h |  1 -
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 234476226529..03e9c887bdfb 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -25,6 +25,16 @@ struct pci_p2pdma {
        bool p2pmem_published;
 };
 
+struct pci_p2pdma_pagemap {
+       struct dev_pagemap pgmap;
+       u64 bus_offset;
+};
+
+static struct pci_p2pdma_pagemap *to_p2p_pgmap(struct dev_pagemap *pgmap)
+{
+       return container_of(pgmap, struct pci_p2pdma_pagemap, pgmap);
+}
+
 static ssize_t size_show(struct device *dev, struct device_attribute *attr,
                         char *buf)
 {
@@ -135,6 +145,7 @@ static int pci_p2pdma_setup(struct pci_dev *pdev)
 int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
                            u64 offset)
 {
+       struct pci_p2pdma_pagemap *p2p_pgmap;
        struct dev_pagemap *pgmap;
        void *addr;
        int error;
@@ -157,14 +168,17 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int 
bar, size_t size,
                        return error;
        }
 
-       pgmap = devm_kzalloc(&pdev->dev, sizeof(*pgmap), GFP_KERNEL);
-       if (!pgmap)
+       p2p_pgmap = devm_kzalloc(&pdev->dev, sizeof(*p2p_pgmap), GFP_KERNEL);
+       if (!p2p_pgmap)
                return -ENOMEM;
+
+       pgmap = &p2p_pgmap->pgmap;
        pgmap->res.start = pci_resource_start(pdev, bar) + offset;
        pgmap->res.end = pgmap->res.start + size - 1;
        pgmap->res.flags = pci_resource_flags(pdev, bar);
        pgmap->type = MEMORY_DEVICE_PCI_P2PDMA;
-       pgmap->pci_p2pdma_bus_offset = pci_bus_address(pdev, bar) -
+
+       p2p_pgmap->bus_offset = pci_bus_address(pdev, bar) -
                pci_resource_start(pdev, bar);
 
        addr = devm_memremap_pages(&pdev->dev, pgmap);
@@ -720,7 +734,7 @@ EXPORT_SYMBOL_GPL(pci_p2pmem_publish);
 int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
                      enum dma_data_direction dir)
 {
-       struct dev_pagemap *pgmap;
+       struct pci_p2pdma_pagemap *p2p_pgmap;
        struct scatterlist *s;
        phys_addr_t paddr;
        int i;
@@ -736,10 +750,10 @@ int pci_p2pdma_map_sg(struct device *dev, struct 
scatterlist *sg, int nents,
                return 0;
 
        for_each_sg(sg, s, nents, i) {
-               pgmap = sg_page(s)->pgmap;
+               p2p_pgmap = to_p2p_pgmap(sg_page(s)->pgmap);
                paddr = sg_phys(s);
 
-               s->dma_address = paddr - pgmap->pci_p2pdma_bus_offset;
+               s->dma_address = paddr - p2p_pgmap->bus_offset;
                sg_dma_len(s) = s->length;
        }
 
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index f8a5b2a19945..b459518ce475 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -112,7 +112,6 @@ struct dev_pagemap {
        struct device *dev;
        enum memory_type type;
        unsigned int flags;
-       u64 pci_p2pdma_bus_offset;
        const struct dev_pagemap_ops *ops;
 };
 
-- 
2.20.1