[deliverable/linux.git] / arch / powerpc / mm / pgtable_32.c

/*
 * This file contains the routines setting up the linux page tables.
 *  -- paulus
 *
 *  Derived from arch/ppc/mm/init.c:
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/highmem.h>

#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/io.h>

#include "mmu_decl.h"

unsigned long ioremap_base;
unsigned long ioremap_bot;
EXPORT_SYMBOL(ioremap_bot);	/* aka VMALLOC_END */
int io_bat_index;

#if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
#define HAVE_BATS	1
#endif

#if defined(CONFIG_FSL_BOOKE)
#define HAVE_TLBCAM	1
#endif

extern char etext[], _stext[];

#ifdef CONFIG_SMP
extern void hash_page_sync(void);
#endif

#ifdef HAVE_BATS
extern unsigned long v_mapped_by_bats(unsigned long va);
extern unsigned long p_mapped_by_bats(unsigned long pa);
void setbat(int index, unsigned long virt, unsigned long phys,
	    unsigned int size, int flags);

#else /* !HAVE_BATS */
#define v_mapped_by_bats(x)	(0UL)
#define p_mapped_by_bats(x)	(0UL)
#endif /* HAVE_BATS */

#ifdef HAVE_TLBCAM
extern unsigned int tlbcam_index;
extern unsigned long v_mapped_by_tlbcam(unsigned long va);
extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
#else /* !HAVE_TLBCAM */
#define v_mapped_by_tlbcam(x)	(0UL)
#define p_mapped_by_tlbcam(x)	(0UL)
#endif /* HAVE_TLBCAM */

#ifdef CONFIG_PTE_64BIT
/* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
#define PGDIR_ORDER	1
#else
#define PGDIR_ORDER	0
#endif

pgd_t *pgd_alloc(struct mm_struct *mm)
{
	pgd_t *ret;

	ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
	return ret;
}

void pgd_free(pgd_t *pgd)
{
	free_pages((unsigned long)pgd, PGDIR_ORDER);
}

__init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
{
	pte_t *pte;
	extern int mem_init_done;
	extern void *early_get_page(void);

	if (mem_init_done) {
		pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
	} else {
		pte = (pte_t *)early_get_page();
		if (pte)
			clear_page(pte);
	}
	return pte;
}

struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
{
	struct page *ptepage;

#ifdef CONFIG_HIGHPTE
	gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
#else
	gfp_t flags = GFP_KERNEL | __GFP_REPEAT;
#endif

	ptepage = alloc_pages(flags, 0);
	if (ptepage)
		clear_highpage(ptepage);
	return ptepage;
}

void pte_free_kernel(pte_t *pte)
{
#ifdef CONFIG_SMP
	hash_page_sync();
#endif
	free_page((unsigned long)pte);
}

void pte_free(struct page *ptepage)
{
#ifdef CONFIG_SMP
	hash_page_sync();
#endif
	__free_page(ptepage);
}

void __iomem *
ioremap(phys_addr_t addr, unsigned long size)
{
	return __ioremap(addr, size, _PAGE_NO_CACHE);
}
EXPORT_SYMBOL(ioremap);

void __iomem *
ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags)
{
	return __ioremap(addr, size, flags);
}
EXPORT_SYMBOL(ioremap_flags);

void __iomem *
__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
{
	unsigned long v, i;
	phys_addr_t p;
	int err;

	/*
	 * Choose an address to map it to.
	 * Once the vmalloc system is running, we use it.
	 * Before then, we use space going down from ioremap_base
	 * (ioremap_bot records where we're up to).
	 */
	p = addr & PAGE_MASK;
	size = PAGE_ALIGN(addr + size) - p;

	/*
	 * If the address lies within the first 16 MB, assume it's in ISA
	 * memory space
	 */
	if (p < 16*1024*1024)
		p += _ISA_MEM_BASE;

	/*
	 * Don't allow anybody to remap normal RAM that we're using.
	 * mem_init() sets high_memory so only do the check after that.
	 */
	if (mem_init_done && (p < virt_to_phys(high_memory))) {
		printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n",
		       (unsigned long long)p, __builtin_return_address(0));
		return NULL;
	}

	if (size == 0)
		return NULL;

	/*
	 * Is it already mapped?  Perhaps overlapped by a previous
	 * BAT mapping.  If the whole area is mapped then we're done,
	 * otherwise remap it since we want to keep the virt addrs for
	 * each request contiguous.
	 *
	 * We make the assumption here that if the bottom and top
	 * of the range we want are mapped then it's mapped to the
	 * same virt address (and this is contiguous).
	 *  -- Cort
	 */
	if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
		goto out;

	if ((v = p_mapped_by_tlbcam(p)))
		goto out;

	if (mem_init_done) {
		struct vm_struct *area;
		area = get_vm_area(size, VM_IOREMAP);
		if (area == 0)
			return NULL;
		v = (unsigned long) area->addr;
	} else {
		v = (ioremap_bot -= size);
	}

	if ((flags & _PAGE_PRESENT) == 0)
		flags |= _PAGE_KERNEL;
	if (flags & _PAGE_NO_CACHE)
		flags |= _PAGE_GUARDED;

	/*
	 * Should check if it is a candidate for a BAT mapping
	 */

	err = 0;
	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
		err = map_page(v+i, p+i, flags);
	if (err) {
		if (mem_init_done)
			vunmap((void *)v);
		return NULL;
	}

out:
	return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
}
EXPORT_SYMBOL(__ioremap);

void iounmap(volatile void __iomem *addr)
{
	/*
	 * If mapped by BATs then there is nothing to do.
	 * Calling vfree() generates a benign warning.
	 */
	if (v_mapped_by_bats((unsigned long)addr)) return;

	if (addr > high_memory && (unsigned long) addr < ioremap_bot)
		vunmap((void *) (PAGE_MASK & (unsigned long)addr));
}
EXPORT_SYMBOL(iounmap);

int map_page(unsigned long va, phys_addr_t pa, int flags)
{
	pmd_t *pd;
	pte_t *pg;
	int err = -ENOMEM;

	/* Use upper 10 bits of VA to index the first level map */
	pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
	/* Use middle 10 bits of VA to index the second-level map */
	pg = pte_alloc_kernel(pd, va);
	if (pg != 0) {
		err = 0;
		/* The PTE should never be already set nor present in the
		 * hash table
		 */
		BUG_ON(pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE));
		set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
						     __pgprot(flags)));
	}
	return err;
}

/*
 * Map in all of physical memory starting at KERNELBASE.
 */
void __init mapin_ram(void)
{
	unsigned long v, p, s, f;
	int ktext;

	s = mmu_mapin_ram();
	v = KERNELBASE + s;
	p = PPC_MEMSTART + s;
	for (; s < total_lowmem; s += PAGE_SIZE) {
		ktext = ((char *) v >= _stext && (char *) v < etext);
		f = ktext ?_PAGE_RAM_TEXT : _PAGE_RAM;
		map_page(v, p, f);
#ifdef CONFIG_PPC_STD_MMU_32
		if (ktext)
			hash_preload(&init_mm, v, 0, 0x300);
#endif
		v += PAGE_SIZE;
		p += PAGE_SIZE;
	}
}

/* is x a power of 4? */
#define is_power_of_4(x)	is_power_of_2(x) && (ffs(x) & 1)

/* Scan the real Linux page tables and return a PTE pointer for
 * a virtual address in a context.
 * Returns true (1) if PTE was found, zero otherwise.  The pointer to
 * the PTE pointer is unmodified if PTE is not found.
 */
int
get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
{
        pgd_t	*pgd;
	pud_t	*pud;
        pmd_t	*pmd;
        pte_t	*pte;
        int     retval = 0;

        pgd = pgd_offset(mm, addr & PAGE_MASK);
        if (pgd) {
		pud = pud_offset(pgd, addr & PAGE_MASK);
		if (pud && pud_present(*pud)) {
			pmd = pmd_offset(pud, addr & PAGE_MASK);
			if (pmd_present(*pmd)) {
				pte = pte_offset_map(pmd, addr & PAGE_MASK);
				if (pte) {
					retval = 1;
					*ptep = pte;
					if (pmdp)
						*pmdp = pmd;
					/* XXX caller needs to do pte_unmap, yuck */
				}
			}
		}
        }
        return(retval);
}

#ifdef CONFIG_DEBUG_PAGEALLOC

static int __change_page_attr(struct page *page, pgprot_t prot)
{
	pte_t *kpte;
	pmd_t *kpmd;
	unsigned long address;

	BUG_ON(PageHighMem(page));
	address = (unsigned long)page_address(page);

	if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address))
		return 0;
	if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
		return -EINVAL;
	set_pte_at(&init_mm, address, kpte, mk_pte(page, prot));
	wmb();
	flush_HPTE(0, address, pmd_val(*kpmd));
	pte_unmap(kpte);

	return 0;
}

/*
 * Change the page attributes of an page in the linear mapping.
 *
 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
 */
static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
{
	int i, err = 0;
	unsigned long flags;

	local_irq_save(flags);
	for (i = 0; i < numpages; i++, page++) {
		err = __change_page_attr(page, prot);
		if (err)
			break;
	}
	local_irq_restore(flags);
	return err;
}


void kernel_map_pages(struct page *page, int numpages, int enable)
{
	if (PageHighMem(page))
		return;

	change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
}
#endif /* CONFIG_DEBUG_PAGEALLOC */
Commit	Line	Data
14cf11af PM	1	/*
	2	* This file contains the routines setting up the linux page tables.
	3	* -- paulus
	4	*
	5	* Derived from arch/ppc/mm/init.c:
	6	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	7	*
	8	* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
	9	* and Cort Dougan (PReP) (cort@cs.nmt.edu)
	10	* Copyright (C) 1996 Paul Mackerras
14cf11af PM	11	*
	12	* Derived from "arch/i386/mm/init.c"
	13	* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
	14	*
	15	* This program is free software; you can redistribute it and/or
	16	* modify it under the terms of the GNU General Public License
	17	* as published by the Free Software Foundation; either version
	18	* 2 of the License, or (at your option) any later version.
	19	*
	20	*/
	21
14cf11af PM	22	#include <linux/kernel.h>
	23	#include <linux/module.h>
	24	#include <linux/types.h>
	25	#include <linux/mm.h>
	26	#include <linux/vmalloc.h>
	27	#include <linux/init.h>
	28	#include <linux/highmem.h>
	29
	30	#include <asm/pgtable.h>
	31	#include <asm/pgalloc.h>
	32	#include <asm/io.h>
	33
	34	#include "mmu_decl.h"
	35
	36	unsigned long ioremap_base;
	37	unsigned long ioremap_bot;
920573bd	38	EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
14cf11af PM	39	int io_bat_index;
	40
	41	#if defined(CONFIG_6xx) \|\| defined(CONFIG_POWER3)
	42	#define HAVE_BATS 1
	43	#endif
	44
	45	#if defined(CONFIG_FSL_BOOKE)
	46	#define HAVE_TLBCAM 1
	47	#endif
	48
	49	extern char etext[], _stext[];
	50
	51	#ifdef CONFIG_SMP
	52	extern void hash_page_sync(void);
	53	#endif
	54
	55	#ifdef HAVE_BATS
	56	extern unsigned long v_mapped_by_bats(unsigned long va);
	57	extern unsigned long p_mapped_by_bats(unsigned long pa);
	58	void setbat(int index, unsigned long virt, unsigned long phys,
	59	unsigned int size, int flags);
	60
	61	#else /* !HAVE_BATS */
	62	#define v_mapped_by_bats(x) (0UL)
	63	#define p_mapped_by_bats(x) (0UL)
	64	#endif /* HAVE_BATS */
	65
	66	#ifdef HAVE_TLBCAM
	67	extern unsigned int tlbcam_index;
	68	extern unsigned long v_mapped_by_tlbcam(unsigned long va);
	69	extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
	70	#else /* !HAVE_TLBCAM */
	71	#define v_mapped_by_tlbcam(x) (0UL)
	72	#define p_mapped_by_tlbcam(x) (0UL)
	73	#endif /* HAVE_TLBCAM */
	74
	75	#ifdef CONFIG_PTE_64BIT
	76	/* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
	77	#define PGDIR_ORDER 1
	78	#else
	79	#define PGDIR_ORDER 0
	80	#endif
	81
	82	pgd_t pgd_alloc(struct mm_struct mm)
	83	{
	84	pgd_t *ret;
	85
	86	ret = (pgd_t *)__get_free_pages(GFP_KERNEL\|__GFP_ZERO, PGDIR_ORDER);
	87	return ret;
	88	}
	89
	90	void pgd_free(pgd_t *pgd)
	91	{
	92	free_pages((unsigned long)pgd, PGDIR_ORDER);
	93	}
	94
f1aed924	95	__init_refok pte_t pte_alloc_one_kernel(struct mm_struct mm, unsigned long address)
14cf11af PM	96	{
	97	pte_t *pte;
	98	extern int mem_init_done;
	99	extern void *early_get_page(void);
	100
	101	if (mem_init_done) {
	102	pte = (pte_t *)__get_free_page(GFP_KERNEL\|__GFP_REPEAT\|__GFP_ZERO);
	103	} else {
	104	pte = (pte_t *)early_get_page();
	105	if (pte)
	106	clear_page(pte);
	107	}
	108	return pte;
	109	}
	110
	111	struct page pte_alloc_one(struct mm_struct mm, unsigned long address)
	112	{
	113	struct page *ptepage;
	114
	115	#ifdef CONFIG_HIGHPTE
3ee1fcac	116	gfp_t flags = GFP_KERNEL \| __GFP_HIGHMEM \| __GFP_REPEAT;
14cf11af	117	#else
3ee1fcac	118	gfp_t flags = GFP_KERNEL \| __GFP_REPEAT;
14cf11af PM	119	#endif
	120
	121	ptepage = alloc_pages(flags, 0);
	122	if (ptepage)
	123	clear_highpage(ptepage);
	124	return ptepage;
	125	}
	126
	127	void pte_free_kernel(pte_t *pte)
	128	{
	129	#ifdef CONFIG_SMP
	130	hash_page_sync();
	131	#endif
	132	free_page((unsigned long)pte);
	133	}
	134
	135	void pte_free(struct page *ptepage)
	136	{
	137	#ifdef CONFIG_SMP
	138	hash_page_sync();
	139	#endif
	140	__free_page(ptepage);
	141	}
	142
14cf11af PM	143	void __iomem *
	144	ioremap(phys_addr_t addr, unsigned long size)
	145	{
	146	return __ioremap(addr, size, _PAGE_NO_CACHE);
	147	}
920573bd	148	EXPORT_SYMBOL(ioremap);
14cf11af	149
68a64357 BH	150	void __iomem *
	151	ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags)
	152	{
	153	return __ioremap(addr, size, flags);
	154	}
	155	EXPORT_SYMBOL(ioremap_flags);
	156
14cf11af PM	157	void __iomem *
	158	__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
	159	{
	160	unsigned long v, i;
	161	phys_addr_t p;
	162	int err;
	163
	164	/*
	165	* Choose an address to map it to.
	166	* Once the vmalloc system is running, we use it.
	167	* Before then, we use space going down from ioremap_base
	168	* (ioremap_bot records where we're up to).
	169	*/
	170	p = addr & PAGE_MASK;
	171	size = PAGE_ALIGN(addr + size) - p;
	172
	173	/*
	174	* If the address lies within the first 16 MB, assume it's in ISA
	175	* memory space
	176	*/
	177	if (p < 1610241024)
	178	p += _ISA_MEM_BASE;
	179
	180	/*
	181	* Don't allow anybody to remap normal RAM that we're using.
	182	* mem_init() sets high_memory so only do the check after that.
	183	*/
7c8c6b97	184	if (mem_init_done && (p < virt_to_phys(high_memory))) {
37f01d64 DG	185	printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n",
37f01d64 DG	186	(unsigned long long)p, __builtin_return_address(0));
14cf11af PM	187	return NULL;
	188	}
	189
	190	if (size == 0)
	191	return NULL;
	192
	193	/*
	194	* Is it already mapped? Perhaps overlapped by a previous
	195	* BAT mapping. If the whole area is mapped then we're done,
	196	* otherwise remap it since we want to keep the virt addrs for
	197	* each request contiguous.
	198	*
	199	* We make the assumption here that if the bottom and top
	200	* of the range we want are mapped then it's mapped to the
	201	* same virt address (and this is contiguous).
	202	* -- Cort
	203	*/
	204	if ((v = p_mapped_by_bats(p)) /&& p_mapped_by_bats(p+size-1)/ )
	205	goto out;
	206
	207	if ((v = p_mapped_by_tlbcam(p)))
	208	goto out;
	209
	210	if (mem_init_done) {
	211	struct vm_struct *area;
	212	area = get_vm_area(size, VM_IOREMAP);
	213	if (area == 0)
	214	return NULL;
	215	v = (unsigned long) area->addr;
	216	} else {
	217	v = (ioremap_bot -= size);
	218	}
	219
	220	if ((flags & _PAGE_PRESENT) == 0)
	221	flags \|= _PAGE_KERNEL;
	222	if (flags & _PAGE_NO_CACHE)
	223	flags \|= _PAGE_GUARDED;
	224
	225	/*
	226	* Should check if it is a candidate for a BAT mapping
	227	*/
	228
	229	err = 0;
	230	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
	231	err = map_page(v+i, p+i, flags);
	232	if (err) {
	233	if (mem_init_done)
	234	vunmap((void *)v);
	235	return NULL;
	236	}
	237
	238	out:
	239	return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
	240	}
920573bd	241	EXPORT_SYMBOL(__ioremap);
14cf11af PM	242
	243	void iounmap(volatile void __iomem *addr)
	244	{
	245	/*
	246	* If mapped by BATs then there is nothing to do.
	247	* Calling vfree() generates a benign warning.
	248	*/
	249	if (v_mapped_by_bats((unsigned long)addr)) return;
	250
	251	if (addr > high_memory && (unsigned long) addr < ioremap_bot)
	252	vunmap((void *) (PAGE_MASK & (unsigned long)addr));
	253	}
920573bd	254	EXPORT_SYMBOL(iounmap);
14cf11af	255
68a64357	256	int map_page(unsigned long va, phys_addr_t pa, int flags)
14cf11af PM	257	{
	258	pmd_t *pd;
	259	pte_t *pg;
	260	int err = -ENOMEM;
	261
14cf11af	262	/* Use upper 10 bits of VA to index the first level map */
d1953c88	263	pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
14cf11af	264	/* Use middle 10 bits of VA to index the second-level map */
e2f2e58e	265	pg = pte_alloc_kernel(pd, va);
14cf11af PM	266	if (pg != 0) {
14cf11af PM	267	err = 0;
3be4e699 BH	268	/* The PTE should never be already set nor present in the
	269	* hash table
	270	*/
	271	BUG_ON(pte_val(*pg) & (_PAGE_PRESENT \| _PAGE_HASHPTE));
	272	set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
	273	__pgprot(flags)));
14cf11af	274	}
14cf11af PM	275	return err;
	276	}
	277
	278	/*
	279	* Map in all of physical memory starting at KERNELBASE.
	280	*/
	281	void __init mapin_ram(void)
	282	{
	283	unsigned long v, p, s, f;
ee4f2ea4	284	int ktext;
14cf11af PM	285
	286	s = mmu_mapin_ram();
	287	v = KERNELBASE + s;
	288	p = PPC_MEMSTART + s;
	289	for (; s < total_lowmem; s += PAGE_SIZE) {
ee4f2ea4 BH	290	ktext = ((char ) v >= _stext && (char ) v < etext);
ee4f2ea4 BH	291	f = ktext ?_PAGE_RAM_TEXT : _PAGE_RAM;
14cf11af	292	map_page(v, p, f);
ee4f2ea4 BH	293	#ifdef CONFIG_PPC_STD_MMU_32
	294	if (ktext)
	295	hash_preload(&init_mm, v, 0, 0x300);
	296	#endif
14cf11af PM	297	v += PAGE_SIZE;
	298	p += PAGE_SIZE;
	299	}
	300	}
	301
14cf11af	302	/* is x a power of 4? */
8dabba5d	303	#define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1)
14cf11af	304
14cf11af PM	305	/* Scan the real Linux page tables and return a PTE pointer for
	306	* a virtual address in a context.
	307	* Returns true (1) if PTE was found, zero otherwise. The pointer to
	308	* the PTE pointer is unmodified if PTE is not found.
	309	*/
	310	int
bab70a4a	311	get_pteptr(struct mm_struct mm, unsigned long addr, pte_t ptep, pmd_t *pmdp)
14cf11af PM	312	{
14cf11af PM	313	pgd_t *pgd;
d1953c88	314	pud_t *pud;
14cf11af PM	315	pmd_t *pmd;
	316	pte_t *pte;
	317	int retval = 0;
	318
	319	pgd = pgd_offset(mm, addr & PAGE_MASK);
	320	if (pgd) {
d1953c88 DG	321	pud = pud_offset(pgd, addr & PAGE_MASK);
	322	if (pud && pud_present(*pud)) {
	323	pmd = pmd_offset(pud, addr & PAGE_MASK);
	324	if (pmd_present(*pmd)) {
	325	pte = pte_offset_map(pmd, addr & PAGE_MASK);
	326	if (pte) {
	327	retval = 1;
	328	*ptep = pte;
	329	if (pmdp)
	330	*pmdp = pmd;
	331	/* XXX caller needs to do pte_unmap, yuck */
	332	}
	333	}
	334	}
14cf11af PM	335	}
	336	return(retval);
	337	}
	338
88df6e90 BH	339	#ifdef CONFIG_DEBUG_PAGEALLOC
	340
	341	static int __change_page_attr(struct page *page, pgprot_t prot)
	342	{
	343	pte_t *kpte;
	344	pmd_t *kpmd;
	345	unsigned long address;
	346
	347	BUG_ON(PageHighMem(page));
	348	address = (unsigned long)page_address(page);
	349
	350	if (v_mapped_by_bats(address) \|\| v_mapped_by_tlbcam(address))
	351	return 0;
	352	if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
	353	return -EINVAL;
	354	set_pte_at(&init_mm, address, kpte, mk_pte(page, prot));
	355	wmb();
	356	flush_HPTE(0, address, pmd_val(*kpmd));
	357	pte_unmap(kpte);
	358
	359	return 0;
	360	}
	361
	362	/*
	363	* Change the page attributes of an page in the linear mapping.
	364	*
	365	* THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
	366	*/
	367	static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
	368	{
	369	int i, err = 0;
	370	unsigned long flags;
	371
	372	local_irq_save(flags);
	373	for (i = 0; i < numpages; i++, page++) {
	374	err = __change_page_attr(page, prot);
	375	if (err)
	376	break;
	377	}
	378	local_irq_restore(flags);
	379	return err;
	380	}
	381
	382
	383	void kernel_map_pages(struct page *page, int numpages, int enable)
	384	{
	385	if (PageHighMem(page))
	386	return;
	387
	388	change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
	389	}
	390	#endif /* CONFIG_DEBUG_PAGEALLOC */