[IA64] prevent MCA when performing MMIO mmap to PCI config space

[sfrench/cifs-2.6.git] / Documentation / ia64 / aliasing.txt

diff --git a/Documentation/ia64/aliasing.txt b/Documentation/ia64/aliasing.txt
index 9a431a7d0f5d6c61d45687d580137f04878ca4a7..aa3e953f0f7b3f2d29e1b84f95c29ef4d088dded 100644 (file)
--- 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