linux/arch/arm/mm/idmap.c
Russell King 516295e5ab ARM: pgtable: add pud-level code
Add pud_offset() et.al. between the pgd and pmd code in preparation of
using pgtable-nopud.h rather than 4level-fixup.h.

This incorporates a fix from Jamie Iles <jamie@jamieiles.com> for
uaccess_with_memcpy.c.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-21 19:24:14 +00:00

91 lines
2.1 KiB
C

#include <linux/kernel.h>
#include <asm/cputype.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
unsigned long prot)
{
pmd_t *pmd = pmd_offset(pud, addr);
addr = (addr & PMD_MASK) | prot;
pmd[0] = __pmd(addr);
addr += SECTION_SIZE;
pmd[1] = __pmd(addr);
flush_pmd_entry(pmd);
}
static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
unsigned long prot)
{
pud_t *pud = pud_offset(pgd, addr);
unsigned long next;
do {
next = pud_addr_end(addr, end);
idmap_add_pmd(pud, addr, next, prot);
} while (pud++, addr = next, addr != end);
}
void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
{
unsigned long prot, next;
prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;
if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
prot |= PMD_BIT4;
pgd += pgd_index(addr);
do {
next = pgd_addr_end(addr, end);
idmap_add_pud(pgd, addr, next, prot);
} while (pgd++, addr = next, addr != end);
}
#ifdef CONFIG_SMP
static void idmap_del_pmd(pud_t *pud, unsigned long addr, unsigned long end)
{
pmd_t *pmd = pmd_offset(pud, addr);
pmd_clear(pmd);
}
static void idmap_del_pud(pgd_t *pgd, unsigned long addr, unsigned long end)
{
pud_t *pud = pud_offset(pgd, addr);
unsigned long next;
do {
next = pud_addr_end(addr, end);
idmap_del_pmd(pud, addr, next);
} while (pud++, addr = next, addr != end);
}
void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end)
{
unsigned long next;
pgd += pgd_index(addr);
do {
next = pgd_addr_end(addr, end);
idmap_del_pud(pgd, addr, next);
} while (pgd++, addr = next, addr != end);
}
#endif
/*
* In order to soft-boot, we need to insert a 1:1 mapping in place of
* the user-mode pages. This will then ensure that we have predictable
* results when turning the mmu off
*/
void setup_mm_for_reboot(char mode)
{
/*
* We need to access to user-mode page tables here. For kernel threads
* we don't have any user-mode mappings so we use the context that we
* "borrowed".
*/
identity_mapping_add(current->active_mm->pgd, 0, TASK_SIZE);
local_flush_tlb_all();
}