Elaborate on the comment for sanitize_e820_map(), epxlaining more what
it does, what it inputs, and what it returns. Rearrange the placement of
this comment to fit kernel conventions, before the routine's code rather
than buried inside it.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The map size counter passed into, and back out of, sanitize_e820_map(),
was an eight bit type (char or u8), as derived from its origins in
legacy BIOS E820 structures. This patch changes that type to an 'int',
to allow this sanitize routine to also be used on larger maps (larger
than the 256 count that fits in a char). The legacy BIOS E820 interface
of course does not change; that remains at 8 bits for this count, holding
up to E820MAX == 128 entries. But the kernel internals can handle more
when those additional memory map entries are passed from the BIOS via
EFI interfaces.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Extend internal boot time memory tables to allow for up to
three entries per node, which may be larger than the 128 E820MAX
entries handled by the legacy BIOS E820 interface. The EFI
interface, if present, is capable of passing memory map
entries for these larger node counts.
This patch requires an earlier patch that rewrote code depending
on these array sizes from using E820MAX explicitly to size loops,
to instead using ARRAY_SIZE() of the applicable array.
Another patch following this one will provide the code to pick
up additional memory entries passed via the EFI interface from
the BIOS and insert them in the following, now enlarged, arrays.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch is motivated by a subsequent patch which will allow for more
memory map entries on EFI supported systems than can be passed via the x86
legacy BIOS E820 interface. The legacy interface is limited to E820MAX ==
128 memory entries, and that "E820MAX" manifest constant was used as the
size for several arrays and loops over those arrays.
The primary change in this patch is to change code loop sizes over those
arrays from using the constant E820MAX, to using the ARRAY_SIZE() macro
evaluated for the array being looped. That way, a subsequent patch can
change the size of some of these arrays, without breaking this code.
This patch also adds a parameter to the sanitize_e820_map() routine,
which had an implicit size for the array passed it of E820MAX entries.
This new parameter explicitly passes the size of said array. Once again,
this will allow a subsequent patch to change that array size for some
calls to sanitize_e820_map() without breaking the code.
As part of enhancing the sanitize_e820_map() interface this way, I further
combined the unnecessarily distinct x86_32 and x86_64 declarations for
this routine into a single, commonly used, declaration.
This patch in itself should make no difference to the resulting kernel
binary.
[ mingo@elte.hu: merged to -tip ]
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Paul Jackson