PCI: Add pci_mmap_resource_range() and use it for ARM64
Starting to leave behind the legacy of the pci_mmap_page_range() interface
which takes "user-visible" BAR addresses. This takes just the resource and
offset.
For now, both APIs coexist and depending on the platform, one is
implemented as a wrapper around the other.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.txt
index 46b95d8..06f1d64 100644
--- a/Documentation/filesystems/sysfs-pci.txt
+++ b/Documentation/filesystems/sysfs-pci.txt
@@ -113,9 +113,13 @@
--------------------------------------
In order to support PCI resource mapping as described above, Linux platform
-code must define HAVE_PCI_MMAP and provide a pci_mmap_page_range function.
-Platforms are free to only support subsets of the mmap functionality, but
-useful return codes should be provided.
+code should ideally define ARCH_GENERIC_PCI_MMAP_RESOURCE and use the generic
+implementation of that functionality. To support the historical interface of
+mmap() through files in /proc/bus/pci, platforms may also set HAVE_PCI_MMAP.
+
+Alternatively, platforms which set HAVE_PCI_MMAP may provide their own
+implementation of pci_mmap_page_range() instead of defining
+ARCH_GENERIC_PCI_MMAP_RESOURCE.
Platforms which support write-combining maps of PCI resources must define
arch_can_pci_mmap_wc() which shall evaluate to non-zero at runtime when