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MIPS: Two-level pagetables for 64-bit kernels with 64KB pages.

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For 64-bit kernels with 64KB pages and two level page tables, there are
42 bits worth of virtual address space This is larger than the 40 bits of
virtual address space obtained with the default 4KB Page size and three
levels, so there are no draw backs for using two level tables with this
configuration.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/761/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
David Daney
2009-12-04 13:52:36 -08:00
committed by Ralf Baechle
parent ef6c1fd662
commit 325f8a0a31
8 changed files with 71 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
arch/mips/mm/pgtable-64.c
View File

@@ -15,23 +15,31 @@
void pgd_init(unsigned long page)
{
unsigned long *p, *end;
unsigned long entry;
#ifdef __PAGETABLE_PMD_FOLDED
entry = (unsigned long)invalid_pte_table;
#else
entry = (unsigned long)invalid_pmd_table;
#endif
p = (unsigned long *) page;
end = p + PTRS_PER_PGD;
while (p < end) {
p[0] = (unsigned long) invalid_pmd_table;
p[1] = (unsigned long) invalid_pmd_table;
p[2] = (unsigned long) invalid_pmd_table;
p[3] = (unsigned long) invalid_pmd_table;
p[4] = (unsigned long) invalid_pmd_table;
p[5] = (unsigned long) invalid_pmd_table;
p[6] = (unsigned long) invalid_pmd_table;
p[7] = (unsigned long) invalid_pmd_table;
p[0] = entry;
p[1] = entry;
p[2] = entry;
p[3] = entry;
p[4] = entry;
p[5] = entry;
p[6] = entry;
p[7] = entry;
p += 8;
}
}
#ifndef __PAGETABLE_PMD_FOLDED
void pmd_init(unsigned long addr, unsigned long pagetable)
{
unsigned long *p, *end;
@@ -40,17 +48,18 @@ void pmd_init(unsigned long addr, unsigned long pagetable)
end = p + PTRS_PER_PMD;
while (p < end) {
p[0] = (unsigned long)pagetable;
p[1] = (unsigned long)pagetable;
p[2] = (unsigned long)pagetable;
p[3] = (unsigned long)pagetable;
p[4] = (unsigned long)pagetable;
p[5] = (unsigned long)pagetable;
p[6] = (unsigned long)pagetable;
p[7] = (unsigned long)pagetable;
p[0] = pagetable;
p[1] = pagetable;
p[2] = pagetable;
p[3] = pagetable;
p[4] = pagetable;
p[5] = pagetable;
p[6] = pagetable;
p[7] = pagetable;
p += 8;
}
}
#endif
void __init pagetable_init(void)
{
@@ -59,8 +68,9 @@ void __init pagetable_init(void)
/* Initialize the entire pgd. */
pgd_init((unsigned long)swapper_pg_dir);
#ifndef __PAGETABLE_PMD_FOLDED
pmd_init((unsigned long)invalid_pmd_table, (unsigned long)invalid_pte_table);
#endif
pgd_base = swapper_pg_dir;
/*
* Fixed mappings: