asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && CONFIG_INDIRECT_PIO
The !CONFIG_GENERIC_IOMAP version of ioport_map uses MMIO_UPPER_LIMIT to prevent users from making I/O accesses outside the expected I/O range - however it erroneously treats MMIO_UPPER_LIMIT as a mask which is contradictory to its other users. The introduction of CONFIG_INDIRECT_PIO, which subtracts an arbitrary amount from IO_SPACE_LIMIT to form MMIO_UPPER_LIMIT, results in ioport_map mangling the given port rather than capping it. We address this by aligning more closely with the CONFIG_GENERIC_IOMAP implementation of ioport_map by using the comparison operator and returning NULL where the port exceeds MMIO_UPPER_LIMIT. Though note that we preserve the existing behavior of masking with IO_SPACE_LIMIT such that we don't break existing buggy drivers that somehow rely on this masking. Fixes: 5745392e ("PCI: Apply the new generic I/O management on PCI IO hosts") Reported-by:Will Deacon <will.deacon@arm.com> Reviewed-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
Andrew Murray <andrew.murray@arm.com> Signed-off-by:
Will Deacon <will.deacon@arm.com>
parent
84c57dbd
Please register or sign in to comment