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ARM: pgtable: use conventional page table code for identity mappings 

Remove some knowledge of our 2-level page table layout from the
identity mapping code - we assume that a step size of PGDIR_SIZE will
allow us to step over all entries.  While this is true today, it won't
be true in the near future.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2010-11-21 11:48:16 +00:00
parent 614dd0585f
commit af3813d6a5
1 changed files with 31 additions and 15 deletions
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46
arch/arm/mm/idmap.c
View File

@ -4,33 +4,49 @@
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
static void idmap_add_pmd(pgd_t *pgd, unsigned long addr, unsigned long end,
unsigned long prot)
{
pmd_t *pmd = pmd_offset(pgd, addr);
addr = (addr & PMD_MASK) | prot;
pmd[0] = __pmd(addr);
addr += SECTION_SIZE;
pmd[1] = __pmd(addr);
flush_pmd_entry(pmd);
}
void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
{
unsigned long prot;
unsigned long prot, next;
prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;
if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
prot |= PMD_BIT4;
for (addr &= PGDIR_MASK; addr < end;) {
pmd_t *pmd = pmd_offset(pgd + pgd_index(addr), addr);
pmd[0] = __pmd(addr | prot);
addr += SECTION_SIZE;
pmd[1] = __pmd(addr | prot);
addr += SECTION_SIZE;
flush_pmd_entry(pmd);
}
pgd += pgd_index(addr);
do {
next = pgd_addr_end(addr, end);
idmap_add_pmd(pgd, addr, next, prot);
} while (pgd++, addr = next, addr != end);
}
#ifdef CONFIG_SMP
static void idmap_del_pmd(pgd_t *pgd, unsigned long addr, unsigned long end)
{
pmd_t *pmd = pmd_offset(pgd, addr);
pmd_clear(pmd);
}
void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end)
{
for (addr &= PGDIR_MASK; addr < end; addr += PGDIR_SIZE) {
pmd_t *pmd = pmd_offset(pgd + pgd_index(addr), addr);
pmd[0] = __pmd(0);
pmd[1] = __pmd(0);
clean_pmd_entry(pmd);
}
unsigned long next;
pgd += pgd_index(addr);
do {
next = pgd_addr_end(addr, end);
idmap_del_pmd(pgd, addr, next);
} while (pgd++, addr = next, addr != end);
}
#endif