arch/sh/mm/fault.c - kernel/msm-4.9 - Gitiles

 /* $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);
 }
	/* $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);
	}