Messages in this thread |  | | Date | Tue, 20 Feb 2007 14:17:17 +1100 | From | David Gibson <> | Subject | Use resource_size_t for serial MMIO addresses |
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Andrew, please apply to -mm. I think these should be good to merge for 2.6.22.
At present, MMIO addresses for serial port (the ->mapbase field in uart_port and other structures) are unsigned longs. This causes problems on some 32-bit platforms which have a >32-bit physical address bus, for example the embedded PowerPC 440GP chip, which has a 36-bit physical address bus, and on-chip serial ports located at an MMIO address above 4GB.
The second patch in this series changes mapbase to a resource_size_t (which can be 64-bit on the problematic platforms) in struct uart_port and struct plat_serial8250_port. It does *not* change the type in serial_struct, because that structure is exposed to userspace. It is therefore unsafe to use setserial to change the address parameters on a port using a mapbase above 4GB.
The first patch in the series contains the damage of the setserial problem. It allows serial ports to be marked with a new UPF_FIXED_PORT flag, which causes any attempts to change the port's type (PIO/MMIO etc.), address or irq with setserial to be ignored. While using setserial to alter the port address is useful for legacy ISA ports, it is generally a bad idea for ports such as on-chip or other hardwired ports where the arch code has good information (from firmware or hardware probing) on the port's type and address.
-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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