linux/arch/sh
Matt Fleming 5d9b4b19f1 sh: Definitions for 3-level page table layout
If using 64-bit PTEs and 4K pages then each page table has 512 entries
(as opposed to 1024 entries with 32-bit PTEs). Unlike MIPS, SH follows
the convention that all structures in the page table (pgd_t, pmd_t,
pgprot_t, etc) must be the same size. Therefore, 64-bit PTEs require
64-bit PGD entries, etc. Using 2-levels of page tables and 64-bit PTEs
it is only possible to map 1GB of virtual address space.

In order to map all 4GB of virtual address space we need to adopt a
3-level page table layout. This actually works out better for
CONFIG_SUPERH32 because we only waste 2 PGD entries on the P1 and P2
areas (which are untranslated) instead of 256.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-12-17 14:31:20 +09:00
..
boards Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6 2009-12-16 10:29:52 -08:00
boot sh: include empty zero page in romImage 2009-12-04 16:26:20 +09:00
cchips sh: mach-hp6xx: Fix up the hp6xx build for hd64461 changes. 2009-05-20 11:27:13 +09:00
configs sh: sh4 scif pdata (sh7750/sh7760/sh4-202) 2009-12-15 12:06:33 +09:00
drivers sh: dma: Kill off bogus dma_sysclass symbol export. 2009-11-13 12:29:19 +09:00
include sh: Definitions for 3-level page table layout 2009-12-17 14:31:20 +09:00
kernel sh: dmaengine support for SH7785 2009-12-17 14:19:33 +09:00
lib sh: Optimised memset for SH4 2009-11-24 16:28:43 +09:00
lib64 sh64: Kill off special clear_page() implementation. 2009-08-04 17:17:00 +09:00
math-emu sh: Minor optimisations to FPU handling 2009-11-24 17:45:38 +09:00
mm sh: Definitions for 3-level page table layout 2009-12-17 14:31:20 +09:00
oprofile sh: oprofile: Fix up count size mismatch for common impl. 2009-11-05 17:13:15 +09:00
tools sh: sh7785lcr: fix prototype board on 32bit MMU mode. 2009-08-28 10:19:13 +09:00
Kconfig Merge branch 'sh/stable-updates' 2009-10-27 17:10:24 +09:00
Kconfig.cpu sh: Tidy up SH-4A boot_cpu_data.flags probing. 2009-06-01 19:50:08 +09:00
Kconfig.debug sh: Remove old early serial console code V2 2009-12-15 12:07:35 +09:00
Makefile sh: Add default uImage rule for se7724, ap325rxa, and migor. 2009-12-04 13:57:40 +09:00