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Diffstat (limited to 'Documentation/ia64/aliasing.txt')
| -rw-r--r-- | Documentation/ia64/aliasing.txt | 12 |
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 |