Diffstat (limited to 'Documentation/ia64/aliasing.txt')
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/ia64/aliasing.txt b/Documentation/ia64/aliasing.txt
index 9a431a7d0f5..aa3e953f0f7 100644
@@ -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