kernel-ark/arch/m32r/mm/fault-nommu.c
Russell King 4b3073e1c5 MM: Pass a PTE pointer to update_mmu_cache() rather than the PTE itself
On VIVT ARM, when we have multiple shared mappings of the same file
in the same MM, we need to ensure that we have coherency across all
copies.  We do this via make_coherent() by making the pages
uncacheable.

This used to work fine, until we allowed highmem with highpte - we
now have a page table which is mapped as required, and is not available
for modification via update_mmu_cache().

Ralf Beache suggested getting rid of the PTE value passed to
update_mmu_cache():

  On MIPS update_mmu_cache() calls __update_tlb() which walks pagetables
  to construct a pointer to the pte again.  Passing a pte_t * is much
  more elegant.  Maybe we might even replace the pte argument with the
  pte_t?

Ben Herrenschmidt would also like the pte pointer for PowerPC:

  Passing the ptep in there is exactly what I want.  I want that
  -instead- of the PTE value, because I have issue on some ppc cases,
  for I$/D$ coherency, where set_pte_at() may decide to mask out the
  _PAGE_EXEC.

So, pass in the mapped page table pointer into update_mmu_cache(), and
remove the PTE value, updating all implementations and call sites to
suit.

Includes a fix from Stephen Rothwell:

  sparc: fix fallout from update_mmu_cache API change

  Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-20 16:41:46 +00:00

135 lines
3.9 KiB
C

/*
* linux/arch/m32r/mm/fault.c
*
* Copyright (c) 2001, 2002 Hitoshi Yamamoto, and H. Kondo
*
* Some code taken from i386 version.
* 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/interrupt.h>
#include <linux/init.h>
#include <linux/vt_kern.h> /* For unblank_screen() */
#include <asm/m32r.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/hardirq.h>
#include <asm/mmu_context.h>
extern void die(const char *, struct pt_regs *, long);
#ifndef CONFIG_SMP
asmlinkage unsigned int tlb_entry_i_dat;
asmlinkage unsigned int tlb_entry_d_dat;
#define tlb_entry_i tlb_entry_i_dat
#define tlb_entry_d tlb_entry_d_dat
#else
unsigned int tlb_entry_i_dat[NR_CPUS];
unsigned int tlb_entry_d_dat[NR_CPUS];
#define tlb_entry_i tlb_entry_i_dat[smp_processor_id()]
#define tlb_entry_d tlb_entry_d_dat[smp_processor_id()]
#endif
void do_BUG(const char *file, int line)
{
bust_spinlocks(1);
printk("kernel BUG at %s:%d!\n", file, line);
}
/*======================================================================*
* do_page_fault()
*======================================================================*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*
* ARGUMENT:
* regs : M32R SP reg.
* error_code : See below
* address : M32R MMU MDEVA reg. (Operand ACE)
* : M32R BPC reg. (Instruction ACE)
*
* error_code :
* bit 0 == 0 means no page found, 1 means protection fault
* bit 1 == 0 means read, 1 means write
* bit 2 == 0 means kernel, 1 means user-mode
*======================================================================*/
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code,
unsigned long address)
{
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
bust_spinlocks(1);
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(" printing bpc:\n");
printk(KERN_ALERT "bpc = %08lx\n", regs->bpc);
die("Oops", regs, error_code);
bust_spinlocks(0);
do_exit(SIGKILL);
}
/*======================================================================*
* update_mmu_cache()
*======================================================================*/
void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr,
pte_t *ptep)
{
BUG();
}
/*======================================================================*
* flush_tlb_page() : flushes one page
*======================================================================*/
void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
BUG();
}
/*======================================================================*
* flush_tlb_range() : flushes a range of pages
*======================================================================*/
void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
BUG();
}
/*======================================================================*
* flush_tlb_mm() : flushes the specified mm context TLB's
*======================================================================*/
void local_flush_tlb_mm(struct mm_struct *mm)
{
BUG();
}
/*======================================================================*
* flush_tlb_all() : flushes all processes TLBs
*======================================================================*/
void local_flush_tlb_all(void)
{
BUG();
}