1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
375 lines
8.2 KiB
C
375 lines
8.2 KiB
C
/* $Id: fault.c,v 1.14 2004/01/13 05:52:11 kkojima Exp $
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*
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* linux/arch/sh/mm/fault.c
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* Copyright (C) 1999 Niibe Yutaka
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* Copyright (C) 2003 Paul Mundt
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*
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* Based on linux/arch/i386/mm/fault.c:
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* Copyright (C) 1995 Linus Torvalds
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*/
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <asm/system.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/pgalloc.h>
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#include <asm/mmu_context.h>
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#include <asm/cacheflush.h>
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#include <asm/kgdb.h>
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extern void die(const char *,struct pt_regs *,long);
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/*
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* This routine handles page faults. It determines the address,
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* and the problem, and then passes it off to one of the appropriate
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* routines.
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*/
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asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
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unsigned long address)
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{
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struct task_struct *tsk;
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struct mm_struct *mm;
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struct vm_area_struct * vma;
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unsigned long page;
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#ifdef CONFIG_SH_KGDB
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if (kgdb_nofault && kgdb_bus_err_hook)
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kgdb_bus_err_hook();
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#endif
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tsk = current;
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mm = tsk->mm;
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/*
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* If we're in an interrupt or have no user
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* context, we must not take the fault..
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*/
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if (in_atomic() || !mm)
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goto no_context;
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down_read(&mm->mmap_sem);
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vma = find_vma(mm, address);
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if (!vma)
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goto bad_area;
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if (vma->vm_start <= address)
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goto good_area;
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if (!(vma->vm_flags & VM_GROWSDOWN))
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goto bad_area;
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if (expand_stack(vma, address))
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goto bad_area;
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/*
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* Ok, we have a good vm_area for this memory access, so
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* we can handle it..
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*/
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good_area:
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if (writeaccess) {
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if (!(vma->vm_flags & VM_WRITE))
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goto bad_area;
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} else {
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if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
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goto bad_area;
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}
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/*
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* If for any reason at all we couldn't handle the fault,
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* make sure we exit gracefully rather than endlessly redo
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* the fault.
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*/
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survive:
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switch (handle_mm_fault(mm, vma, address, writeaccess)) {
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case VM_FAULT_MINOR:
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tsk->min_flt++;
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break;
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case VM_FAULT_MAJOR:
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tsk->maj_flt++;
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break;
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case VM_FAULT_SIGBUS:
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goto do_sigbus;
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case VM_FAULT_OOM:
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goto out_of_memory;
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default:
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BUG();
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}
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up_read(&mm->mmap_sem);
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return;
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/*
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* Something tried to access memory that isn't in our memory map..
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* Fix it, but check if it's kernel or user first..
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*/
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bad_area:
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up_read(&mm->mmap_sem);
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if (user_mode(regs)) {
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tsk->thread.address = address;
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tsk->thread.error_code = writeaccess;
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force_sig(SIGSEGV, tsk);
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return;
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}
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no_context:
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/* Are we prepared to handle this kernel fault? */
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if (fixup_exception(regs))
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return;
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/*
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* Oops. The kernel tried to access some bad page. We'll have to
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* terminate things with extreme prejudice.
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*
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*/
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if (address < PAGE_SIZE)
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printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
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else
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printk(KERN_ALERT "Unable to handle kernel paging request");
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printk(" at virtual address %08lx\n", address);
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printk(KERN_ALERT "pc = %08lx\n", regs->pc);
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asm volatile("mov.l %1, %0"
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: "=r" (page)
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: "m" (__m(MMU_TTB)));
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if (page) {
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page = ((unsigned long *) page)[address >> 22];
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printk(KERN_ALERT "*pde = %08lx\n", page);
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if (page & _PAGE_PRESENT) {
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page &= PAGE_MASK;
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address &= 0x003ff000;
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page = ((unsigned long *) __va(page))[address >> PAGE_SHIFT];
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printk(KERN_ALERT "*pte = %08lx\n", page);
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}
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}
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die("Oops", regs, writeaccess);
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do_exit(SIGKILL);
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/*
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* We ran out of memory, or some other thing happened to us that made
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* us unable to handle the page fault gracefully.
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*/
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out_of_memory:
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up_read(&mm->mmap_sem);
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if (current->pid == 1) {
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yield();
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down_read(&mm->mmap_sem);
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goto survive;
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}
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printk("VM: killing process %s\n", tsk->comm);
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if (user_mode(regs))
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do_exit(SIGKILL);
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goto no_context;
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do_sigbus:
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up_read(&mm->mmap_sem);
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/*
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* Send a sigbus, regardless of whether we were in kernel
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* or user mode.
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*/
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tsk->thread.address = address;
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tsk->thread.error_code = writeaccess;
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tsk->thread.trap_no = 14;
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force_sig(SIGBUS, tsk);
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/* Kernel mode? Handle exceptions or die */
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if (!user_mode(regs))
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goto no_context;
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}
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/*
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* Called with interrupt disabled.
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*/
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asmlinkage int __do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
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unsigned long address)
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{
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unsigned long addrmax = P4SEG;
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pgd_t *dir;
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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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#ifdef CONFIG_SH_KGDB
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if (kgdb_nofault && kgdb_bus_err_hook)
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kgdb_bus_err_hook();
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#endif
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#ifdef CONFIG_SH_STORE_QUEUES
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addrmax = P4SEG_STORE_QUE + 0x04000000;
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#endif
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if (address >= P3SEG && address < addrmax)
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dir = pgd_offset_k(address);
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else if (address >= TASK_SIZE)
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return 1;
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else if (!current->mm)
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return 1;
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else
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dir = pgd_offset(current->mm, address);
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pmd = pmd_offset(dir, address);
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if (pmd_none(*pmd))
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return 1;
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if (pmd_bad(*pmd)) {
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pmd_ERROR(*pmd);
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pmd_clear(pmd);
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return 1;
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}
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pte = pte_offset_kernel(pmd, address);
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entry = *pte;
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if (pte_none(entry) || pte_not_present(entry)
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|| (writeaccess && !pte_write(entry)))
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return 1;
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if (writeaccess)
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entry = pte_mkdirty(entry);
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entry = pte_mkyoung(entry);
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#ifdef CONFIG_CPU_SH4
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/*
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* ITLB is not affected by "ldtlb" instruction.
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* So, we need to flush the entry by ourselves.
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*/
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{
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unsigned long flags;
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local_irq_save(flags);
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__flush_tlb_page(get_asid(), address&PAGE_MASK);
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local_irq_restore(flags);
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}
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#endif
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set_pte(pte, entry);
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update_mmu_cache(NULL, address, entry);
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return 0;
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}
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void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
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{
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if (vma->vm_mm && vma->vm_mm->context != NO_CONTEXT) {
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unsigned long flags;
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unsigned long asid;
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unsigned long saved_asid = MMU_NO_ASID;
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asid = vma->vm_mm->context & MMU_CONTEXT_ASID_MASK;
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page &= PAGE_MASK;
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local_irq_save(flags);
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if (vma->vm_mm != current->mm) {
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saved_asid = get_asid();
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set_asid(asid);
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}
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__flush_tlb_page(asid, page);
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if (saved_asid != MMU_NO_ASID)
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set_asid(saved_asid);
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local_irq_restore(flags);
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}
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}
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void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
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unsigned long end)
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{
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struct mm_struct *mm = vma->vm_mm;
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if (mm->context != NO_CONTEXT) {
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unsigned long flags;
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int size;
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local_irq_save(flags);
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size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
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if (size > (MMU_NTLB_ENTRIES/4)) { /* Too many TLB to flush */
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mm->context = NO_CONTEXT;
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if (mm == current->mm)
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activate_context(mm);
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} else {
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unsigned long asid = mm->context&MMU_CONTEXT_ASID_MASK;
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unsigned long saved_asid = MMU_NO_ASID;
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start &= PAGE_MASK;
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end += (PAGE_SIZE - 1);
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end &= PAGE_MASK;
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if (mm != current->mm) {
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saved_asid = get_asid();
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set_asid(asid);
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}
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while (start < end) {
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__flush_tlb_page(asid, start);
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start += PAGE_SIZE;
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}
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if (saved_asid != MMU_NO_ASID)
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set_asid(saved_asid);
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}
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local_irq_restore(flags);
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}
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}
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void flush_tlb_kernel_range(unsigned long start, unsigned long end)
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{
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unsigned long flags;
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int size;
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local_irq_save(flags);
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size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
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if (size > (MMU_NTLB_ENTRIES/4)) { /* Too many TLB to flush */
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flush_tlb_all();
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} else {
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unsigned long asid = init_mm.context&MMU_CONTEXT_ASID_MASK;
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unsigned long saved_asid = get_asid();
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start &= PAGE_MASK;
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end += (PAGE_SIZE - 1);
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end &= PAGE_MASK;
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set_asid(asid);
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while (start < end) {
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__flush_tlb_page(asid, start);
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start += PAGE_SIZE;
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}
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set_asid(saved_asid);
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}
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local_irq_restore(flags);
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}
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void flush_tlb_mm(struct mm_struct *mm)
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{
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/* Invalidate all TLB of this process. */
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/* Instead of invalidating each TLB, we get new MMU context. */
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if (mm->context != NO_CONTEXT) {
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unsigned long flags;
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local_irq_save(flags);
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mm->context = NO_CONTEXT;
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if (mm == current->mm)
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activate_context(mm);
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local_irq_restore(flags);
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}
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}
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void flush_tlb_all(void)
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{
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unsigned long flags, status;
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/*
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* Flush all the TLB.
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*
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* Write to the MMU control register's bit:
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* TF-bit for SH-3, TI-bit for SH-4.
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* It's same position, bit #2.
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*/
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local_irq_save(flags);
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status = ctrl_inl(MMUCR);
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status |= 0x04;
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ctrl_outl(status, MMUCR);
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local_irq_restore(flags);
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}
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