MIPS: Expand __swp_offset() to carry 40 significant bits for 64-bit kernel.
authorDavid Daney <david.daney@cavium.com>
Tue, 24 Feb 2015 23:35:34 +0000 (15:35 -0800)
committerRalf Baechle <ralf@linux-mips.org>
Wed, 1 Apr 2015 15:21:59 +0000 (17:21 +0200)
commit5ae03b1220ac22b823d8414997329806db16020c
treec82b4fbb8edf5593ab2deddc057fbd6561eb680f
parent80aaaa8b93d860f828e2cf883f307894640765f0
MIPS: Expand __swp_offset() to carry 40 significant bits for 64-bit kernel.

With CONFIG_MIGRATION, the PFN of the migrating pages is stored in
__swp_offset(), so we must have enough bits to store the largest
possible PFN.  OCTEON NUMA systems have 41 bits of physical address
space, so with 4K pages (12-bits), we need at least 29 bits to store
the PFN.

The current width of 24-bits is too narrow, so expand it all the way
out to 40-bits.  This leaves the low order 16 bits as zero which does
not interfere with any of the PTE bits.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9315/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
arch/mips/include/asm/pgtable-64.h