1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/ia64/aliasing.txt b/Documentation/ia64/aliasing.txt
index 9a431a7d0f5d..aa3e953f0f7b 100644
--- a/Documentation/ia64/aliasing.txt
+++ b/Documentation/ia64/aliasing.txt
@@ -112,6 +112,18 @@ POTENTIAL ATTRIBUTE ALIASING CASES
 
         The /dev/mem mmap constraints apply.
 
+    mmap of /proc/bus/pci/.../??.?
+
+        This is an MMIO mmap of PCI functions, which additionally may or
+        may not be requested as using the WC attribute.
+
+        If WC is requested, and the region in kern_memmap is either WC
+        or UC, and the EFI memory map designates the region as WC, then
+        the WC mapping is allowed.
+
+        Otherwise, the user mapping must use the same attribute as the
+        kernel mapping.
+
     read/write of /dev/mem
 
         This uses copy_from_user(), which implicitly uses a kernel