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