linux/arch/xtensa
Johannes Weiner c947a585ab xtensa: cope with ram beginning at higher addresses
The current assumption of the memory code is that the first RAM PFN in
the system is 0.

Adjust the relevant code to play well with setups where memory starts
at higher addresses, indicated by PLATFORM_DEFAULT_MEM_START.

The new memory model looks like this:

+----------+--+----------------------+----------------+
|          |  |                      |                |
|          |  |         RAM          |                |
|          |  |                      |                |
+----------+--+----------------------+----------------+
|          |  |                      |                |
+- PFN 0   |  +- min_low_pfn         +- max_low_pfn   +- max_pfn
           |
           +- ARCH_PFN_OFFSET
           +- PLATFORM_DEFAULT_MEM_START >> PAGE_SIZE

The memory map contains pages starting from pfn ARCH_PFN_OFFSET up to
max_low_pfn.  The only zone used right now will span exactly the same
region.

Usually, ARCH_PFN_OFFSET and min_low_pfn are the same value.  Handle
them separately for robustness.  Gapping pages will be in the memory
map but marked as reserved and won't be touched.

Signed-off-by: Johannes Weiner <jw@emlix.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
2009-04-02 23:41:08 -07:00
..
boot xtensa: move headers files to arch/xtensa/include 2008-11-06 10:25:09 -08:00
configs [PATCH] xtensa: remove extra header files 2006-12-10 09:55:39 -08:00
include/asm xtensa: cope with ram beginning at higher addresses 2009-04-02 23:41:08 -07:00
kernel xtensa: use correct stack pointer for stack traces 2009-04-02 23:38:57 -07:00
lib xtensa: move headers files to arch/xtensa/include 2008-11-06 10:25:09 -08:00
mm xtensa: cope with ram beginning at higher addresses 2009-04-02 23:41:08 -07:00
platforms proc tty: switch xtensa iss console to ->proc_fops 2009-04-01 08:59:10 -07:00
variants xtensa: move headers files to arch/xtensa/include 2008-11-06 10:25:09 -08:00
Kconfig xtensa: beat Kconfig into shape 2009-04-02 23:38:35 -07:00
Kconfig.debug [PATCH] xtensa: Architecture support for Tensilica Xtensa Part 1 2005-06-24 00:05:21 -07:00
Makefile xtensa: move headers files to arch/xtensa/include 2008-11-06 10:25:09 -08:00