PCI: Add managed pcim_iomap_range()

The only managed mapping function currently is pcim_iomap() which doesn't
allow for mapping an area starting at a certain offset, which many drivers
want.

Add pcim_iomap_range() as an exported function.

Link: https://lore.kernel.org/r/20240613115032.29098-13-pstanner@redhat.com
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index f4a0af2c4d79fa5ee89a5d19a0fb2bb9e8cc615c..3780a9f9ec003e625ea00900e917d82852e3cbf2 100644 (file)
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -1027,3 +1027,47 @@ void pcim_iounmap_regions(struct pci_dev *pdev, int mask)
        }
 }
 EXPORT_SYMBOL(pcim_iounmap_regions);
+
+/**
+ * pcim_iomap_range - Create a ranged __iomap mapping within a PCI BAR
+ * @pdev: PCI device to map IO resources for
+ * @bar: Index of the BAR
+ * @offset: Offset from the begin of the BAR
+ * @len: Length in bytes for the mapping
+ *
+ * Returns: __iomem pointer on success, an IOMEM_ERR_PTR on failure.
+ *
+ * Creates a new IO-Mapping within the specified @bar, ranging from @offset to
+ * @offset + @len.
+ *
+ * The mapping will automatically get unmapped on driver detach. If desired,
+ * release manually only with pcim_iounmap().
+ */
+void __iomem *pcim_iomap_range(struct pci_dev *pdev, int bar,
+               unsigned long offset, unsigned long len)
+{
+       void __iomem *mapping;
+       struct pcim_addr_devres *res;
+
+       res = pcim_addr_devres_alloc(pdev);
+       if (!res)
+               return IOMEM_ERR_PTR(-ENOMEM);
+
+       mapping = pci_iomap_range(pdev, bar, offset, len);
+       if (!mapping) {
+               pcim_addr_devres_free(res);
+               return IOMEM_ERR_PTR(-EINVAL);
+       }
+
+       res->type = PCIM_ADDR_DEVRES_TYPE_MAPPING;
+       res->baseaddr = mapping;
+
+       /*
+        * Ranged mappings don't get added to the legacy-table, since the table
+        * only ever keeps track of whole BARs.
+        */
+
+       devres_add(&pdev->dev, res);
+       return mapping;
+}
+EXPORT_SYMBOL(pcim_iomap_range);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0c19f0717899f41b61752e8926d61232d6c632b4..98893a89bb5b931362785b73ca2d189f6c84dcfa 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2303,6 +2303,8 @@ int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name);
 int pcim_iomap_regions_request_all(struct pci_dev *pdev, int mask,
                                   const char *name);
 void pcim_iounmap_regions(struct pci_dev *pdev, int mask);
+void __iomem *pcim_iomap_range(struct pci_dev *pdev, int bar,
+                               unsigned long offset, unsigned long len);
 
 extern int pci_pci_problems;
 #define PCIPCI_FAIL            1       /* No PCI PCI DMA */