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#include <linux/kernel.h>
#include <asm/cputype.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
{
unsigned long prot;
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);
}
}
#ifdef CONFIG_SMP
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);
}
}
#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();
}
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