Hi, in some elderly code for a VME-supporting 824x-board from our company I found the following line in ppc_md.setup_io_mappings():
io_block_mapping(0x80000000, 0x80000000, 0x10000000, _PAGE_IO); This is obviously meant to map a window of VME IO memory into virtual address space. What puzzles me is that the mapping is located below PAGE_OFFSET (0xc0000000), which, from my general understanding, is bad :( But since apparently nobody had a problem with this for years, (and ranges above PAGE_OFFSET are tight) I'd like to know what the actual implications are. Ok, should a process ever access this range, it would fail (since the BATs go first and allow only supervisor access(?)), but a user process ever using such a high address seems highly unlikely. What I worry more is that it might introduce some security holes or stability problems, any thoughts? Thanks, -- Stefan Nickl Kontron Modular Computers ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
