602 lines
15 KiB
C
602 lines
15 KiB
C
/*
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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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* arch/sh64/mm/fault.c
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*
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* Copyright (C) 2000, 2001 Paolo Alberelli
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* Copyright (C) 2003 Richard Curnow (/proc/tlb, bug fixes)
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* Copyright (C) 2003 Paul Mundt
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*
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*/
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#include <linux/signal.h>
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#include <linux/rwsem.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 <asm/system.h>
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#include <asm/io.h>
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#include <asm/tlb.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/registers.h> /* required by inline asm statements */
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#if defined(CONFIG_SH64_PROC_TLB)
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#include <linux/init.h>
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#include <linux/proc_fs.h>
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/* Count numbers of tlb refills in each region */
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static unsigned long long calls_to_update_mmu_cache = 0ULL;
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static unsigned long long calls_to_flush_tlb_page = 0ULL;
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static unsigned long long calls_to_flush_tlb_range = 0ULL;
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static unsigned long long calls_to_flush_tlb_mm = 0ULL;
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static unsigned long long calls_to_flush_tlb_all = 0ULL;
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unsigned long long calls_to_do_slow_page_fault = 0ULL;
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unsigned long long calls_to_do_fast_page_fault = 0ULL;
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/* Count size of ranges for flush_tlb_range */
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static unsigned long long flush_tlb_range_1 = 0ULL;
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static unsigned long long flush_tlb_range_2 = 0ULL;
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static unsigned long long flush_tlb_range_3_4 = 0ULL;
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static unsigned long long flush_tlb_range_5_7 = 0ULL;
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static unsigned long long flush_tlb_range_8_11 = 0ULL;
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static unsigned long long flush_tlb_range_12_15 = 0ULL;
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static unsigned long long flush_tlb_range_16_up = 0ULL;
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static unsigned long long page_not_present = 0ULL;
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#endif
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extern void die(const char *,struct pt_regs *,long);
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#define PFLAG(val,flag) (( (val) & (flag) ) ? #flag : "" )
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#define PPROT(flag) PFLAG(pgprot_val(prot),flag)
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static inline void print_prots(pgprot_t prot)
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{
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printk("prot is 0x%08lx\n",pgprot_val(prot));
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printk("%s %s %s %s %s\n",PPROT(_PAGE_SHARED),PPROT(_PAGE_READ),
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PPROT(_PAGE_EXECUTE),PPROT(_PAGE_WRITE),PPROT(_PAGE_USER));
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}
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static inline void print_vma(struct vm_area_struct *vma)
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{
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printk("vma start 0x%08lx\n", vma->vm_start);
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printk("vma end 0x%08lx\n", vma->vm_end);
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print_prots(vma->vm_page_prot);
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printk("vm_flags 0x%08lx\n", vma->vm_flags);
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}
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static inline void print_task(struct task_struct *tsk)
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{
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printk("Task pid %d\n", tsk->pid);
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}
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static pte_t *lookup_pte(struct mm_struct *mm, unsigned long address)
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{
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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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dir = pgd_offset(mm, address);
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if (pgd_none(*dir)) {
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return NULL;
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}
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pmd = pmd_offset(dir, address);
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if (pmd_none(*pmd)) {
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return NULL;
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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)) {
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return NULL;
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}
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if (!pte_present(entry)) {
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return NULL;
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}
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return pte;
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}
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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 textaccess, 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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const struct exception_table_entry *fixup;
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pte_t *pte;
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#if defined(CONFIG_SH64_PROC_TLB)
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++calls_to_do_slow_page_fault;
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#endif
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/* SIM
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* Note this is now called with interrupts still disabled
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* This is to cope with being called for a missing IO port
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* address with interupts disabled. This should be fixed as
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* soon as we have a better 'fast path' miss handler.
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*
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* Plus take care how you try and debug this stuff.
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* For example, writing debug data to a port which you
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* have just faulted on is not going to work.
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*/
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tsk = current;
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mm = tsk->mm;
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/* Not an IO address, so reenable interrupts */
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local_irq_enable();
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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_interrupt() || !mm)
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goto no_context;
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/* TLB misses upon some cache flushes get done under cli() */
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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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#ifdef DEBUG_FAULT
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print_task(tsk);
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printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
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__FUNCTION__,__LINE__,
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address,regs->pc,textaccess,writeaccess);
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show_regs(regs);
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#endif
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goto bad_area;
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}
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if (vma->vm_start <= address) {
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goto good_area;
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}
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if (!(vma->vm_flags & VM_GROWSDOWN)) {
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#ifdef DEBUG_FAULT
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print_task(tsk);
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printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
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__FUNCTION__,__LINE__,
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address,regs->pc,textaccess,writeaccess);
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show_regs(regs);
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print_vma(vma);
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#endif
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goto bad_area;
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}
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if (expand_stack(vma, address)) {
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#ifdef DEBUG_FAULT
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print_task(tsk);
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printk("%s:%d fault, address is 0x%08x PC %016Lx textaccess %d writeaccess %d\n",
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__FUNCTION__,__LINE__,
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address,regs->pc,textaccess,writeaccess);
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show_regs(regs);
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#endif
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goto bad_area;
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}
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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 (textaccess) {
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if (!(vma->vm_flags & VM_EXEC))
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goto bad_area;
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} else {
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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))
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goto bad_area;
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}
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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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default:
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goto out_of_memory;
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}
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/* If we get here, the page fault has been handled. Do the TLB refill
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now from the newly-setup PTE, to avoid having to fault again right
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away on the same instruction. */
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pte = lookup_pte (mm, address);
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if (!pte) {
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/* From empirical evidence, we can get here, due to
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!pte_present(pte). (e.g. if a swap-in occurs, and the page
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is swapped back out again before the process that wanted it
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gets rescheduled?) */
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goto no_pte;
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}
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__do_tlb_refill(address, textaccess, pte);
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no_pte:
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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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#ifdef DEBUG_FAULT
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printk("fault:bad area\n");
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#endif
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up_read(&mm->mmap_sem);
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if (user_mode(regs)) {
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static int count=0;
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siginfo_t info;
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if (count < 4) {
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/* This is really to help debug faults when starting
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* usermode, so only need a few */
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count++;
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printk("user mode bad_area address=%08lx pid=%d (%s) pc=%08lx\n",
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address, current->pid, current->comm,
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(unsigned long) regs->pc);
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#if 0
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show_regs(regs);
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#endif
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}
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if (tsk->pid == 1) {
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panic("INIT had user mode bad_area\n");
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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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info.si_signo = SIGSEGV;
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info.si_errno = 0;
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info.si_addr = (void *) address;
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force_sig_info(SIGSEGV, &info, tsk);
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return;
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}
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no_context:
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#ifdef DEBUG_FAULT
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printk("fault:No context\n");
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#endif
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/* Are we prepared to handle this kernel fault? */
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fixup = search_exception_tables(regs->pc);
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if (fixup) {
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regs->pc = fixup->fixup;
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return;
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}
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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%08Lx\n", regs->pc >> 32, regs->pc & 0xffffffff);
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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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if (current->pid == 1) {
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panic("INIT out of memory\n");
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yield();
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goto survive;
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}
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printk("fault:Out of memory\n");
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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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printk("fault:Do sigbus\n");
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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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void flush_tlb_all(void);
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void update_mmu_cache(struct vm_area_struct * vma,
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unsigned long address, pte_t pte)
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{
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#if defined(CONFIG_SH64_PROC_TLB)
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++calls_to_update_mmu_cache;
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#endif
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/*
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* This appears to get called once for every pte entry that gets
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* established => I don't think it's efficient to try refilling the
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* TLBs with the pages - some may not get accessed even. Also, for
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* executable pages, it is impossible to determine reliably here which
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* TLB they should be mapped into (or both even).
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*
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* So, just do nothing here and handle faults on demand. In the
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* TLBMISS handling case, the refill is now done anyway after the pte
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* has been fixed up, so that deals with most useful cases.
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*/
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}
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static void __flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
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{
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unsigned long long match, pteh=0, lpage;
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unsigned long tlb;
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struct mm_struct *mm;
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mm = vma->vm_mm;
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if (mm->context == NO_CONTEXT)
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return;
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/*
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* Sign-extend based on neff.
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*/
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lpage = (page & NEFF_SIGN) ? (page | NEFF_MASK) : page;
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match = ((mm->context & MMU_CONTEXT_ASID_MASK) << PTEH_ASID_SHIFT) | PTEH_VALID;
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match |= lpage;
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/* Do ITLB : don't bother for pages in non-exectutable VMAs */
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if (vma->vm_flags & VM_EXEC) {
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for_each_itlb_entry(tlb) {
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asm volatile ("getcfg %1, 0, %0"
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: "=r" (pteh)
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: "r" (tlb) );
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if (pteh == match) {
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__flush_tlb_slot(tlb);
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break;
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}
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}
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}
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/* Do DTLB : any page could potentially be in here. */
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for_each_dtlb_entry(tlb) {
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asm volatile ("getcfg %1, 0, %0"
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: "=r" (pteh)
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: "r" (tlb) );
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if (pteh == match) {
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__flush_tlb_slot(tlb);
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break;
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}
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}
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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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unsigned long flags;
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#if defined(CONFIG_SH64_PROC_TLB)
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++calls_to_flush_tlb_page;
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#endif
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if (vma->vm_mm) {
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page &= PAGE_MASK;
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local_irq_save(flags);
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__flush_tlb_page(vma, page);
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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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unsigned long flags;
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unsigned long long match, pteh=0, pteh_epn, pteh_low;
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unsigned long tlb;
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struct mm_struct *mm;
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mm = vma->vm_mm;
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#if defined(CONFIG_SH64_PROC_TLB)
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++calls_to_flush_tlb_range;
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{
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unsigned long size = (end - 1) - start;
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size >>= 12; /* divide by PAGE_SIZE */
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size++; /* end=start+4096 => 1 page */
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switch (size) {
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case 1 : flush_tlb_range_1++; break;
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case 2 : flush_tlb_range_2++; break;
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case 3 ... 4 : flush_tlb_range_3_4++; break;
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case 5 ... 7 : flush_tlb_range_5_7++; break;
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case 8 ... 11 : flush_tlb_range_8_11++; break;
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case 12 ... 15 : flush_tlb_range_12_15++; break;
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default : flush_tlb_range_16_up++; break;
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}
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}
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#endif
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if (mm->context == NO_CONTEXT)
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return;
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local_irq_save(flags);
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start &= PAGE_MASK;
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end &= PAGE_MASK;
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match = ((mm->context & MMU_CONTEXT_ASID_MASK) << PTEH_ASID_SHIFT) | PTEH_VALID;
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/* Flush ITLB */
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for_each_itlb_entry(tlb) {
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asm volatile ("getcfg %1, 0, %0"
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: "=r" (pteh)
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: "r" (tlb) );
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pteh_epn = pteh & PAGE_MASK;
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pteh_low = pteh & ~PAGE_MASK;
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if (pteh_low == match && pteh_epn >= start && pteh_epn <= end)
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__flush_tlb_slot(tlb);
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}
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/* Flush DTLB */
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for_each_dtlb_entry(tlb) {
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asm volatile ("getcfg %1, 0, %0"
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: "=r" (pteh)
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: "r" (tlb) );
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pteh_epn = pteh & PAGE_MASK;
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pteh_low = pteh & ~PAGE_MASK;
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if (pteh_low == match && pteh_epn >= start && pteh_epn <= end)
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__flush_tlb_slot(tlb);
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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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unsigned long flags;
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#if defined(CONFIG_SH64_PROC_TLB)
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++calls_to_flush_tlb_mm;
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#endif
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if (mm->context == NO_CONTEXT)
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return;
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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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void flush_tlb_all(void)
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{
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/* Invalidate all, including shared pages, excluding fixed TLBs */
|
|
|
|
unsigned long flags, tlb;
|
|
|
|
#if defined(CONFIG_SH64_PROC_TLB)
|
|
++calls_to_flush_tlb_all;
|
|
#endif
|
|
|
|
local_irq_save(flags);
|
|
|
|
/* Flush each ITLB entry */
|
|
for_each_itlb_entry(tlb) {
|
|
__flush_tlb_slot(tlb);
|
|
}
|
|
|
|
/* Flush each DTLB entry */
|
|
for_each_dtlb_entry(tlb) {
|
|
__flush_tlb_slot(tlb);
|
|
}
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
|
|
{
|
|
/* FIXME: Optimize this later.. */
|
|
flush_tlb_all();
|
|
}
|
|
|
|
#if defined(CONFIG_SH64_PROC_TLB)
|
|
/* Procfs interface to read the performance information */
|
|
|
|
static int
|
|
tlb_proc_info(char *buf, char **start, off_t fpos, int length, int *eof, void *data)
|
|
{
|
|
int len=0;
|
|
len += sprintf(buf+len, "do_fast_page_fault called %12lld times\n", calls_to_do_fast_page_fault);
|
|
len += sprintf(buf+len, "do_slow_page_fault called %12lld times\n", calls_to_do_slow_page_fault);
|
|
len += sprintf(buf+len, "update_mmu_cache called %12lld times\n", calls_to_update_mmu_cache);
|
|
len += sprintf(buf+len, "flush_tlb_page called %12lld times\n", calls_to_flush_tlb_page);
|
|
len += sprintf(buf+len, "flush_tlb_range called %12lld times\n", calls_to_flush_tlb_range);
|
|
len += sprintf(buf+len, "flush_tlb_mm called %12lld times\n", calls_to_flush_tlb_mm);
|
|
len += sprintf(buf+len, "flush_tlb_all called %12lld times\n", calls_to_flush_tlb_all);
|
|
len += sprintf(buf+len, "flush_tlb_range_sizes\n"
|
|
" 1 : %12lld\n"
|
|
" 2 : %12lld\n"
|
|
" 3 - 4 : %12lld\n"
|
|
" 5 - 7 : %12lld\n"
|
|
" 8 - 11 : %12lld\n"
|
|
"12 - 15 : %12lld\n"
|
|
"16+ : %12lld\n",
|
|
flush_tlb_range_1, flush_tlb_range_2, flush_tlb_range_3_4,
|
|
flush_tlb_range_5_7, flush_tlb_range_8_11, flush_tlb_range_12_15,
|
|
flush_tlb_range_16_up);
|
|
len += sprintf(buf+len, "page not present %12lld times\n", page_not_present);
|
|
*eof = 1;
|
|
return len;
|
|
}
|
|
|
|
static int __init register_proc_tlb(void)
|
|
{
|
|
create_proc_read_entry("tlb", 0, NULL, tlb_proc_info, NULL);
|
|
return 0;
|
|
}
|
|
|
|
__initcall(register_proc_tlb);
|
|
|
|
#endif
|