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