From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 20 Feb 2007 14:17:17 +1100 From: David Gibson To: Andrew Morton Subject: Use resource_size_t for serial MMIO addresses Message-ID: <20070220031717.GI17818@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, Russell King List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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