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/*
* TLB miss handler for SH with an MMU.
*
* Copyright (C) 1999 Niibe Yutaka
* Copyright (C) 2003 - 2012 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <asm/mmu_context.h>
#include <asm/thread_info.h>
/*
* Called with interrupts disabled.
*/
asmlinkage int __kprobes
handle_tlbmiss(struct pt_regs *regs, unsigned long error_code,
unsigned long address)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pte_t entry;
/*
* We don't take page faults for P1, P2, and parts of P4, these
* are always mapped, whether it be due to legacy behaviour in
* 29-bit mode, or due to PMB configuration in 32-bit mode.
*/
if (address >= P3SEG && address < P3_ADDR_MAX) {
pgd = pgd_offset_k(address);
} else {
if (unlikely(address >= TASK_SIZE || !current->mm))
return 1;
pgd = pgd_offset(current->mm, address);
}
p4d = p4d_offset(pgd, address);
if (p4d_none_or_clear_bad(p4d))
return 1;
pud = pud_offset(p4d, address);
if (pud_none_or_clear_bad(pud))
return 1;
pmd = pmd_offset(pud, address);
if (pmd_none_or_clear_bad(pmd))
return 1;
pte = pte_offset_kernel(pmd, address);
entry = *pte;
if (unlikely(pte_none(entry) || pte_not_present(entry)))
return 1;
if (unlikely(error_code && !pte_write(entry)))
return 1;
if (error_code)
entry = pte_mkdirty(entry);
entry = pte_mkyoung(entry);
set_pte(pte, entry);
#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SMP)
/*
* SH-4 does not set MMUCR.RC to the corresponding TLB entry in
* the case of an initial page write exception, so we need to
* flush it in order to avoid potential TLB entry duplication.
*/
if (error_code == FAULT_CODE_INITIAL)
local_flush_tlb_one(get_asid(), address & PAGE_MASK);
#endif
set_thread_fault_code(error_code);
update_mmu_cache(NULL, address, pte);
return 0;
}
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