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/*
* linux/arch/arm/mm/fault-armo.c
*
* Copyright (C) 1995 Linus Torvalds
* Modifications for ARM processor (c) 1995-1999 Russell King
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#define FAULT_CODE_FORCECOW 0x80
#define FAULT_CODE_PREFETCH 0x04
#define FAULT_CODE_WRITE 0x02
#define FAULT_CODE_USER 0x01
#define DO_COW(m) ((m) & (FAULT_CODE_WRITE|FAULT_CODE_FORCECOW))
#define READ_FAULT(m) (!((m) & FAULT_CODE_WRITE))
#include "fault-common.c"
static void *alloc_table(int size, int prio)
{
if (size != 128)
printk("invalid table size\n");
return (void *)get_page_8k(prio);
}
void free_table(void *table)
{
free_page_8k((unsigned long)table);
}
pgd_t *get_pgd_slow(void)
{
pgd_t *pgd = (pgd_t *)alloc_table(PTRS_PER_PGD * BYTES_PER_PTR, GFP_KERNEL);
pgd_t *init;
if (pgd) {
init = pgd_offset(&init_mm, 0);
memzero(pgd, USER_PTRS_PER_PGD * BYTES_PER_PTR);
memcpy(pgd + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * BYTES_PER_PTR);
}
return pgd;
}
pte_t *get_pte_slow(pmd_t *pmd, unsigned long offset)
{
pte_t *pte;
pte = (pte_t *)alloc_table(PTRS_PER_PTE * BYTES_PER_PTR, GFP_KERNEL);
if (pmd_none(*pmd)) {
if (pte) {
memzero(pte, PTRS_PER_PTE * BYTES_PER_PTR);
set_pmd(pmd, mk_pmd(pte));
return pte + offset;
}
set_pmd(pmd, mk_pmd(BAD_PAGETABLE));
return NULL;
}
free_table((void *)pte);
if (pmd_bad(*pmd)) {
__bad_pmd(pmd);
return NULL;
}
return (pte_t *) pmd_page(*pmd) + offset;
}
/*
* Handle a data abort. Note that we have to handle a range of addresses
* on ARM2/3 for ldm. If both pages are zero-mapped, then we have to force
* a copy-on-write. However, on the second page, we always force COW.
*/
asmlinkage void
do_DataAbort(unsigned long min_addr, unsigned long max_addr, int mode, struct pt_regs *regs)
{
do_page_fault(min_addr, mode, regs);
if ((min_addr ^ max_addr) >> PAGE_SHIFT)
do_page_fault(max_addr, mode | FAULT_CODE_FORCECOW, regs);
}
asmlinkage int
do_PrefetchAbort(unsigned long addr, struct pt_regs *regs)
{
#if 0
if (the memc mapping for this page exists - can check now...) {
printk ("Page in, but got abort (undefined instruction?)\n");
return 0;
}
#endif
do_page_fault(addr, FAULT_CODE_USER|FAULT_CODE_PREFETCH, regs);
return 1;
}
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