[linux-2.6-block.git] / arch / sh / mm / fault_32.c

/*
 * Page fault handler for SH with an MMU.
 *
 *  Copyright (C) 1999  Niibe Yutaka
 *  Copyright (C) 2003 - 2009  Paul Mundt
 *
 *  Based on linux/arch/i386/mm/fault.c:
 *   Copyright (C) 1995  Linus Torvalds
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/hardirq.h>
#include <linux/kprobes.h>
#include <linux/perf_event.h>
#include <asm/io_trapped.h>
#include <asm/system.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>

static inline int notify_page_fault(struct pt_regs *regs, int trap)
{
	int ret = 0;

	if (kprobes_built_in() && !user_mode(regs)) {
		preempt_disable();
		if (kprobe_running() && kprobe_fault_handler(regs, trap))
			ret = 1;
		preempt_enable();
	}

	return ret;
}

static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
{
	unsigned index = pgd_index(address);
	pgd_t *pgd_k;
	pud_t *pud, *pud_k;
	pmd_t *pmd, *pmd_k;

	pgd += index;
	pgd_k = init_mm.pgd + index;

	if (!pgd_present(*pgd_k))
		return NULL;

	pud = pud_offset(pgd, address);
	pud_k = pud_offset(pgd_k, address);
	if (!pud_present(*pud_k))
		return NULL;

	if (!pud_present(*pud))
	    set_pud(pud, *pud_k);

	pmd = pmd_offset(pud, address);
	pmd_k = pmd_offset(pud_k, address);
	if (!pmd_present(*pmd_k))
		return NULL;

	if (!pmd_present(*pmd))
		set_pmd(pmd, *pmd_k);
	else {
		/*
		 * The page tables are fully synchronised so there must
		 * be another reason for the fault. Return NULL here to
		 * signal that we have not taken care of the fault.
		 */
		BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k));
		return NULL;
	}

	return pmd_k;
}

/*
 * Handle a fault on the vmalloc or module mapping area
 */
static noinline int vmalloc_fault(unsigned long address)
{
	pgd_t *pgd_k;
	pmd_t *pmd_k;
	pte_t *pte_k;

	/* Make sure we are in vmalloc/module/P3 area: */
	if (!(address >= VMALLOC_START && address < P3_ADDR_MAX))
		return -1;

	/*
	 * Synchronize this task's top level page-table
	 * with the 'reference' page table.
	 *
	 * Do _not_ use "current" here. We might be inside
	 * an interrupt in the middle of a task switch..
	 */
	pgd_k = get_TTB();
	pmd_k = vmalloc_sync_one(pgd_k, address);
	if (!pmd_k)
		return -1;

	pte_k = pte_offset_kernel(pmd_k, address);
	if (!pte_present(*pte_k))
		return -1;

	return 0;
}

static int fault_in_kernel_space(unsigned long address)
{
	return address >= TASK_SIZE;
}

/*
 * 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 __kprobes do_page_fault(struct pt_regs *regs,
					unsigned long writeaccess,
					unsigned long address)
{
	unsigned long vec;
	struct task_struct *tsk;
	struct mm_struct *mm;
	struct vm_area_struct * vma;
	int si_code;
	int fault;
	siginfo_t info;

	tsk = current;
	mm = tsk->mm;
	si_code = SEGV_MAPERR;
	vec = lookup_exception_vector();

	/*
	 * We fault-in kernel-space virtual memory on-demand. The
	 * 'reference' page table is init_mm.pgd.
	 *
	 * NOTE! We MUST NOT take any locks for this case. We may
	 * be in an interrupt or a critical region, and should
	 * only copy the information from the master page table,
	 * nothing more.
	 */
	if (unlikely(fault_in_kernel_space(address))) {
		if (vmalloc_fault(address) >= 0)
			return;
		if (notify_page_fault(regs, vec))
			return;

		goto bad_area_nosemaphore;
	}

	if (unlikely(notify_page_fault(regs, vec)))
		return;

	/* Only enable interrupts if they were on before the fault */
	if ((regs->sr & SR_IMASK) != SR_IMASK)
		local_irq_enable();

	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address);

	/*
	 * If we're in an interrupt, have no user context or are running
	 * in an atomic region then 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:
	si_code = SEGV_ACCERR;
	if (writeaccess) {
		if (!(vma->vm_flags & VM_WRITE))
			goto bad_area;
	} else {
		if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
			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.
	 */
	fault = handle_mm_fault(mm, vma, address, writeaccess ? FAULT_FLAG_WRITE : 0);
	if (unlikely(fault & VM_FAULT_ERROR)) {
		if (fault & VM_FAULT_OOM)
			goto out_of_memory;
		else if (fault & VM_FAULT_SIGBUS)
			goto do_sigbus;
		BUG();
	}
	if (fault & VM_FAULT_MAJOR) {
		tsk->maj_flt++;
		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0,
				     regs, address);
	} else {
		tsk->min_flt++;
		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0,
				     regs, address);
	}

	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);

bad_area_nosemaphore:
	if (user_mode(regs)) {
		info.si_signo = SIGSEGV;
		info.si_errno = 0;
		info.si_code = si_code;
		info.si_addr = (void *) address;
		force_sig_info(SIGSEGV, &info, tsk);
		return;
	}

no_context:
	/* Are we prepared to handle this kernel fault?  */
	if (fixup_exception(regs))
		return;

	if (handle_trapped_io(regs, address))
		return;
/*
 * Oops. The kernel tried to access some bad page. We'll have to
 * terminate things with extreme prejudice.
 *
 */

	bust_spinlocks(1);

	if (oops_may_print()) {
		unsigned long page;

		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);
		page = (unsigned long)get_TTB();
		if (page) {
			page = ((__typeof__(page) *)page)[address >> PGDIR_SHIFT];
			printk(KERN_ALERT "*pde = %08lx\n", page);
			if (page & _PAGE_PRESENT) {
				page &= PAGE_MASK;
				address &= 0x003ff000;
				page = ((__typeof__(page) *)
						__va(page))[address >>
							    PAGE_SHIFT];
				printk(KERN_ALERT "*pte = %08lx\n", page);
			}
		}
	}

	die("Oops", regs, writeaccess);
	bust_spinlocks(0);
	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 (!user_mode(regs))
		goto no_context;
	pagefault_out_of_memory();
	return;

do_sigbus:
	up_read(&mm->mmap_sem);

	/*
	 * Send a sigbus, regardless of whether we were in kernel
	 * or user mode.
	 */
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_ADRERR;
	info.si_addr = (void *)address;
	force_sig_info(SIGBUS, &info, tsk);

	/* Kernel mode? Handle exceptions or die */
	if (!user_mode(regs))
		goto no_context;
}

/*
 * Called with interrupts disabled.
 */
asmlinkage int __kprobes
handle_tlbmiss(struct pt_regs *regs, unsigned long writeaccess,
	       unsigned long address)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;
	pte_t entry;

	/*
	 * We don't take page faults for P1, P2, and parts of P4, these
	 * are always mapped, whether it be due to legacy behaviour in
	 * 29-bit mode, or due to PMB configuration in 32-bit mode.
	 */
	if (address >= P3SEG && address < P3_ADDR_MAX) {
		pgd = pgd_offset_k(address);
	} else {
		if (unlikely(address >= TASK_SIZE || !current->mm))
			return 1;

		pgd = pgd_offset(current->mm, address);
	}

	pud = pud_offset(pgd, address);
	if (pud_none_or_clear_bad(pud))
		return 1;
	pmd = pmd_offset(pud, address);
	if (pmd_none_or_clear_bad(pmd))
		return 1;
	pte = pte_offset_kernel(pmd, address);
	entry = *pte;
	if (unlikely(pte_none(entry) || pte_not_present(entry)))
		return 1;
	if (unlikely(writeaccess && !pte_write(entry)))
		return 1;

	if (writeaccess)
		entry = pte_mkdirty(entry);
	entry = pte_mkyoung(entry);

	set_pte(pte, entry);

#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SMP)
	/*
	 * SH-4 does not set MMUCR.RC to the corresponding TLB entry in
	 * the case of an initial page write exception, so we need to
	 * flush it in order to avoid potential TLB entry duplication.
	 */
	if (writeaccess == 2)
		local_flush_tlb_one(get_asid(), address & PAGE_MASK);
#endif

	update_mmu_cache(NULL, address, pte);

	return 0;
}
Commit	Line	Data
26ff6c11 PM	1	/*
26ff6c11 PM	2	* Page fault handler for SH with an MMU.
1da177e4	3	*
1da177e4	4	* Copyright (C) 1999 Niibe Yutaka
0f60bb25	5	* Copyright (C) 2003 - 2009 Paul Mundt
1da177e4 LT	6	*
	7	* Based on linux/arch/i386/mm/fault.c:
	8	* Copyright (C) 1995 Linus Torvalds
26ff6c11 PM	9	*
	10	* This file is subject to the terms and conditions of the GNU General Public
	11	* License. See the file "COPYING" in the main directory of this archive
	12	* for more details.
1da177e4	13	*/
1da177e4	14	#include <linux/kernel.h>
1da177e4	15	#include <linux/mm.h>
0f08f338 PM	16	#include <linux/hardirq.h>
0f08f338 PM	17	#include <linux/kprobes.h>
cdd6c482	18	#include <linux/perf_event.h>
e7cc9a73	19	#include <asm/io_trapped.h>
1da177e4	20	#include <asm/system.h>
1da177e4	21	#include <asm/mmu_context.h>
db2e1fa3	22	#include <asm/tlbflush.h>
1da177e4	23
7433ab77 PM	24	static inline int notify_page_fault(struct pt_regs *regs, int trap)
	25	{
	26	int ret = 0;
	27
c63c3105	28	if (kprobes_built_in() && !user_mode(regs)) {
7433ab77 PM	29	preempt_disable();
	30	if (kprobe_running() && kprobe_fault_handler(regs, trap))
	31	ret = 1;
	32	preempt_enable();
	33	}
7433ab77 PM	34
	35	return ret;
	36	}
	37
0f60bb25 PM	38	static inline pmd_t vmalloc_sync_one(pgd_t pgd, unsigned long address)
	39	{
	40	unsigned index = pgd_index(address);
	41	pgd_t *pgd_k;
	42	pud_t pud, pud_k;
	43	pmd_t pmd, pmd_k;
	44
	45	pgd += index;
	46	pgd_k = init_mm.pgd + index;
	47
	48	if (!pgd_present(*pgd_k))
	49	return NULL;
	50
	51	pud = pud_offset(pgd, address);
	52	pud_k = pud_offset(pgd_k, address);
	53	if (!pud_present(*pud_k))
	54	return NULL;
	55
5d9b4b19 MF	56	if (!pud_present(*pud))
	57	set_pud(pud, *pud_k);
	58
0f60bb25 PM	59	pmd = pmd_offset(pud, address);
	60	pmd_k = pmd_offset(pud_k, address);
	61	if (!pmd_present(*pmd_k))
	62	return NULL;
	63
	64	if (!pmd_present(*pmd))
	65	set_pmd(pmd, *pmd_k);
05dd2cd3 MF	66	else {
	67	/*
	68	* The page tables are fully synchronised so there must
	69	* be another reason for the fault. Return NULL here to
	70	* signal that we have not taken care of the fault.
	71	*/
0f60bb25	72	BUG_ON(pmd_page(pmd) != pmd_page(pmd_k));
05dd2cd3 MF	73	return NULL;
05dd2cd3 MF	74	}
0f60bb25 PM	75
	76	return pmd_k;
	77	}
	78
	79	/*
	80	* Handle a fault on the vmalloc or module mapping area
	81	*/
	82	static noinline int vmalloc_fault(unsigned long address)
	83	{
	84	pgd_t *pgd_k;
	85	pmd_t *pmd_k;
	86	pte_t *pte_k;
	87
0906a3ad PM	88	/* Make sure we are in vmalloc/module/P3 area: */
0906a3ad PM	89	if (!(address >= VMALLOC_START && address < P3_ADDR_MAX))
0f60bb25 PM	90	return -1;
	91
	92	/*
	93	* Synchronize this task's top level page-table
	94	* with the 'reference' page table.
	95	*
	96	* Do _not_ use "current" here. We might be inside
	97	* an interrupt in the middle of a task switch..
	98	*/
	99	pgd_k = get_TTB();
05dd2cd3	100	pmd_k = vmalloc_sync_one(pgd_k, address);
0f60bb25 PM	101	if (!pmd_k)
	102	return -1;
	103
	104	pte_k = pte_offset_kernel(pmd_k, address);
	105	if (!pte_present(*pte_k))
	106	return -1;
	107
	108	return 0;
	109	}
	110
	111	static int fault_in_kernel_space(unsigned long address)
	112	{
	113	return address >= TASK_SIZE;
	114	}
	115
1da177e4 LT	116	/*
	117	* This routine handles page faults. It determines the address,
	118	* and the problem, and then passes it off to one of the appropriate
	119	* routines.
	120	*/
b5a1bcbe SM	121	asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
	122	unsigned long writeaccess,
	123	unsigned long address)
1da177e4	124	{
0f60bb25	125	unsigned long vec;
1da177e4 LT	126	struct task_struct *tsk;
	127	struct mm_struct *mm;
	128	struct vm_area_struct * vma;
b5a1bcbe	129	int si_code;
83c54070	130	int fault;
b5a1bcbe	131	siginfo_t info;
1da177e4	132
1da177e4	133	tsk = current;
0f60bb25	134	mm = tsk->mm;
b5a1bcbe	135	si_code = SEGV_MAPERR;
0f60bb25	136	vec = lookup_exception_vector();
1da177e4	137
0f60bb25 PM	138	/*
	139	* We fault-in kernel-space virtual memory on-demand. The
	140	* 'reference' page table is init_mm.pgd.
	141	*
	142	* NOTE! We MUST NOT take any locks for this case. We may
	143	* be in an interrupt or a critical region, and should
	144	* only copy the information from the master page table,
	145	* nothing more.
	146	*/
	147	if (unlikely(fault_in_kernel_space(address))) {
	148	if (vmalloc_fault(address) >= 0)
99a596f9	149	return;
0f60bb25	150	if (notify_page_fault(regs, vec))
96e14e54	151	return;
99a596f9	152
0f60bb25	153	goto bad_area_nosemaphore;
99a596f9 SM	154	}
99a596f9 SM	155
0f60bb25	156	if (unlikely(notify_page_fault(regs, vec)))
7433ab77 PM	157	return;
7433ab77 PM	158
f2fb4e4f	159	/* Only enable interrupts if they were on before the fault */
7433ab77	160	if ((regs->sr & SR_IMASK) != SR_IMASK)
f2fb4e4f	161	local_irq_enable();
f2fb4e4f	162
cdd6c482	163	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address);
f2fb4e4f	164
1da177e4	165	/*
0f60bb25 PM	166	* If we're in an interrupt, have no user context or are running
0f60bb25 PM	167	* in an atomic region then we must not take the fault:
1da177e4 LT	168	*/
	169	if (in_atomic() \|\| !mm)
	170	goto no_context;
	171
	172	down_read(&mm->mmap_sem);
	173
	174	vma = find_vma(mm, address);
	175	if (!vma)
	176	goto bad_area;
	177	if (vma->vm_start <= address)
	178	goto good_area;
	179	if (!(vma->vm_flags & VM_GROWSDOWN))
	180	goto bad_area;
	181	if (expand_stack(vma, address))
	182	goto bad_area;
0f60bb25 PM	183
	184	/*
	185	* Ok, we have a good vm_area for this memory access, so
	186	* we can handle it..
	187	*/
1da177e4	188	good_area:
b5a1bcbe	189	si_code = SEGV_ACCERR;
1da177e4 LT	190	if (writeaccess) {
	191	if (!(vma->vm_flags & VM_WRITE))
	192	goto bad_area;
	193	} else {
df67b3da	194	if (!(vma->vm_flags & (VM_READ \| VM_EXEC \| VM_WRITE)))
1da177e4 LT	195	goto bad_area;
	196	}
	197
	198	/*
	199	* If for any reason at all we couldn't handle the fault,
	200	* make sure we exit gracefully rather than endlessly redo
	201	* the fault.
	202	*/
d06063cc	203	fault = handle_mm_fault(mm, vma, address, writeaccess ? FAULT_FLAG_WRITE : 0);
83c54070 NP	204	if (unlikely(fault & VM_FAULT_ERROR)) {
83c54070 NP	205	if (fault & VM_FAULT_OOM)
1da177e4	206	goto out_of_memory;
83c54070 NP	207	else if (fault & VM_FAULT_SIGBUS)
	208	goto do_sigbus;
	209	BUG();
1da177e4	210	}
7433ab77	211	if (fault & VM_FAULT_MAJOR) {
83c54070	212	tsk->maj_flt++;
cdd6c482	213	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0,
7433ab77 PM	214	regs, address);
7433ab77 PM	215	} else {
83c54070	216	tsk->min_flt++;
cdd6c482	217	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0,
7433ab77 PM	218	regs, address);
7433ab77 PM	219	}
1da177e4 LT	220
	221	up_read(&mm->mmap_sem);
	222	return;
	223
0f60bb25 PM	224	/*
	225	* Something tried to access memory that isn't in our memory map..
	226	* Fix it, but check if it's kernel or user first..
	227	*/
1da177e4 LT	228	bad_area:
	229	up_read(&mm->mmap_sem);
	230
99a596f9	231	bad_area_nosemaphore:
1da177e4	232	if (user_mode(regs)) {
b5a1bcbe SM	233	info.si_signo = SIGSEGV;
	234	info.si_errno = 0;
	235	info.si_code = si_code;
	236	info.si_addr = (void *) address;
	237	force_sig_info(SIGSEGV, &info, tsk);
1da177e4 LT	238	return;
	239	}
	240
	241	no_context:
	242	/* Are we prepared to handle this kernel fault? */
	243	if (fixup_exception(regs))
	244	return;
	245
e7cc9a73 MD	246	if (handle_trapped_io(regs, address))
e7cc9a73 MD	247	return;
1da177e4 LT	248	/*
	249	* Oops. The kernel tried to access some bad page. We'll have to
	250	* terminate things with extreme prejudice.
	251	*
	252	*/
0630e45c PM	253
	254	bust_spinlocks(1);
	255
	256	if (oops_may_print()) {
b62ad83d	257	unsigned long page;
0630e45c PM	258
	259	if (address < PAGE_SIZE)
	260	printk(KERN_ALERT "Unable to handle kernel NULL "
	261	"pointer dereference");
	262	else
	263	printk(KERN_ALERT "Unable to handle kernel paging "
	264	"request");
	265	printk(" at virtual address %08lx\n", address);
	266	printk(KERN_ALERT "pc = %08lx\n", regs->pc);
	267	page = (unsigned long)get_TTB();
	268	if (page) {
06f862c8	269	page = ((__typeof__(page) *)page)[address >> PGDIR_SHIFT];
0630e45c PM	270	printk(KERN_ALERT "*pde = %08lx\n", page);
	271	if (page & _PAGE_PRESENT) {
	272	page &= PAGE_MASK;
	273	address &= 0x003ff000;
	274	page = ((__typeof__(page) *)
	275	__va(page))[address >>
	276	PAGE_SHIFT];
	277	printk(KERN_ALERT "*pte = %08lx\n", page);
	278	}
1da177e4 LT	279	}
1da177e4 LT	280	}
0630e45c	281
1da177e4	282	die("Oops", regs, writeaccess);
0630e45c	283	bust_spinlocks(0);
1da177e4 LT	284	do_exit(SIGKILL);
	285
	286	/*
	287	* We ran out of memory, or some other thing happened to us that made
	288	* us unable to handle the page fault gracefully.
	289	*/
	290	out_of_memory:
	291	up_read(&mm->mmap_sem);
6b6b18e6 NP	292	if (!user_mode(regs))
	293	goto no_context;
	294	pagefault_out_of_memory();
	295	return;
1da177e4 LT	296
	297	do_sigbus:
	298	up_read(&mm->mmap_sem);
	299
	300	/*
	301	* Send a sigbus, regardless of whether we were in kernel
	302	* or user mode.
	303	*/
b5a1bcbe SM	304	info.si_signo = SIGBUS;
	305	info.si_errno = 0;
	306	info.si_code = BUS_ADRERR;
	307	info.si_addr = (void *)address;
	308	force_sig_info(SIGBUS, &info, tsk);
1da177e4 LT	309
	310	/* Kernel mode? Handle exceptions or die */
	311	if (!user_mode(regs))
	312	goto no_context;
	313	}
db2e1fa3	314
db2e1fa3 PM	315	/*
	316	* Called with interrupts disabled.
	317	*/
112e5847 PM	318	asmlinkage int __kprobes
	319	handle_tlbmiss(struct pt_regs *regs, unsigned long writeaccess,
	320	unsigned long address)
db2e1fa3 PM	321	{
	322	pgd_t *pgd;
	323	pud_t *pud;
	324	pmd_t *pmd;
	325	pte_t *pte;
	326	pte_t entry;
3d58695e	327
db2e1fa3 PM	328	/*
	329	* We don't take page faults for P1, P2, and parts of P4, these
	330	* are always mapped, whether it be due to legacy behaviour in
	331	* 29-bit mode, or due to PMB configuration in 32-bit mode.
	332	*/
	333	if (address >= P3SEG && address < P3_ADDR_MAX) {
	334	pgd = pgd_offset_k(address);
db2e1fa3	335	} else {
0f1a394b	336	if (unlikely(address >= TASK_SIZE \|\| !current->mm))
8010fbe7	337	return 1;
db2e1fa3	338
0f1a394b	339	pgd = pgd_offset(current->mm, address);
db2e1fa3 PM	340	}
	341
	342	pud = pud_offset(pgd, address);
	343	if (pud_none_or_clear_bad(pud))
8010fbe7	344	return 1;
db2e1fa3 PM	345	pmd = pmd_offset(pud, address);
db2e1fa3 PM	346	if (pmd_none_or_clear_bad(pmd))
8010fbe7	347	return 1;
0f1a394b	348	pte = pte_offset_kernel(pmd, address);
db2e1fa3 PM	349	entry = *pte;
db2e1fa3 PM	350	if (unlikely(pte_none(entry) \|\| pte_not_present(entry)))
8010fbe7	351	return 1;
db2e1fa3	352	if (unlikely(writeaccess && !pte_write(entry)))
8010fbe7	353	return 1;
db2e1fa3 PM	354
	355	if (writeaccess)
	356	entry = pte_mkdirty(entry);
	357	entry = pte_mkyoung(entry);
	358
8010fbe7 PM	359	set_pte(pte, entry);
8010fbe7 PM	360
a602cc05 HS	361	#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SMP)
a602cc05 HS	362	/*
8010fbe7 PM	363	* SH-4 does not set MMUCR.RC to the corresponding TLB entry in
	364	* the case of an initial page write exception, so we need to
	365	* flush it in order to avoid potential TLB entry duplication.
a602cc05	366	*/
8010fbe7 PM	367	if (writeaccess == 2)
8010fbe7 PM	368	local_flush_tlb_one(get_asid(), address & PAGE_MASK);
a602cc05 HS	369	#endif
a602cc05 HS	370
4b3073e1	371	update_mmu_cache(NULL, address, pte);
0f1a394b	372
8010fbe7	373	return 0;
db2e1fa3	374	}