linux-sg2042/Documentation/ia64
Bjorn Helgaas 32e62c636a [IA64] rework memory attribute aliasing
This closes a couple holes in our attribute aliasing avoidance scheme:

  - The current kernel fails mmaps of some /dev/mem MMIO regions because
    they don't appear in the EFI memory map.  This keeps X from working
    on the Intel Tiger box.

  - The current kernel allows UC mmap of the 0-1MB region of
    /sys/.../legacy_mem even when the chipset doesn't support UC
    access.  This causes an MCA when starting X on HP rx7620 and rx8620
    boxes in the default configuration.

There's more detail in the Documentation/ia64/aliasing.txt file this
adds, but the general idea is that if a region might be covered by
a granule-sized kernel identity mapping, any access via /dev/mem or
mmap must use the same attribute as the identity mapping.

Otherwise, we fall back to using an attribute that is supported
according to the EFI memory map, or to using UC if the EFI memory
map doesn't mention the region.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-05-08 16:32:05 -07:00
..
IRQ-redir.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
README Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
aliasing.txt [IA64] rework memory attribute aliasing 2006-05-08 16:32:05 -07:00
efirtc.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fsys.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mca.txt [IA64] Add Documentation/ia64/mca.txt 2005-09-16 10:34:16 -07:00
serial.txt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00

README

        Linux kernel release 2.4.xx for the IA-64 Platform

   These are the release notes for Linux version 2.4 for IA-64
   platform.  This document provides information specific to IA-64
   ONLY, to get additional information about the Linux kernel also
   read the original Linux README provided with the kernel.

INSTALLING the kernel:

 - IA-64 kernel installation is the same as the other platforms, see
   original README for details.


SOFTWARE REQUIREMENTS

   Compiling and running this kernel requires an IA-64 compliant GCC
   compiler.  And various software packages also compiled with an
   IA-64 compliant GCC compiler.


CONFIGURING the kernel:

   Configuration is the same, see original README for details.


COMPILING the kernel:

 - Compiling this kernel doesn't differ from other platform so read
   the original README for details BUT make sure you have an IA-64
   compliant GCC compiler.

IA-64 SPECIFICS

 - General issues:

    o Hardly any performance tuning has been done. Obvious targets
      include the library routines (IP checksum, etc.). Less
      obvious targets include making sure we don't flush the TLB
      needlessly, etc.

    o SMP locks cleanup/optimization

    o IA32 support.  Currently experimental.  It mostly works.