[mirror_ubuntu-zesty-kernel.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 <linux/memblock.h>
#include <linux/slab.h>

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

#include "mmu_decl.h"

unsigned long ioremap_bot;
EXPORT_SYMBOL(ioremap_bot);	/* aka VMALLOC_END */

extern char etext[], _stext[], _sinittext[], _einittext[];

__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
{
	pte_t *pte;

	if (slab_is_available()) {
		pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
	} else {
		pte = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
		if (pte)
			clear_page(pte);
	}
	return pte;
}

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

	gfp_t flags = GFP_KERNEL | __GFP_ZERO;

	ptepage = alloc_pages(flags, 0);
	if (!ptepage)
		return NULL;
	if (!pgtable_page_ctor(ptepage)) {
		__free_page(ptepage);
		return NULL;
	}
	return ptepage;
}

void __iomem *
ioremap(phys_addr_t addr, unsigned long size)
{
	return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED,
				__builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap);

void __iomem *
ioremap_wc(phys_addr_t addr, unsigned long size)
{
	return __ioremap_caller(addr, size, _PAGE_NO_CACHE,
				__builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_wc);

void __iomem *
ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
{
	/* writeable implies dirty for kernel addresses */
	if ((flags & (_PAGE_RW | _PAGE_RO)) != _PAGE_RO)
		flags |= _PAGE_DIRTY | _PAGE_HWWRITE;

	/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
	flags &= ~(_PAGE_USER | _PAGE_EXEC);

#ifdef _PAGE_BAP_SR
	/* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
	 * which means that we just cleared supervisor access... oops ;-) This
	 * restores it
	 */
	flags |= _PAGE_BAP_SR;
#endif

	return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_prot);

void __iomem *
__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
{
	return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
}

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

	/* Make sure we have the base flags */
	if ((flags & _PAGE_PRESENT) == 0)
		flags |= pgprot_val(PAGE_KERNEL);

	/* Non-cacheable page cannot be coherent */
	if (flags & _PAGE_NO_CACHE)
		flags &= ~_PAGE_COHERENT;

	/*
	 * 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_TOP
	 * (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;

#ifndef CONFIG_CRASH_DUMP
	/*
	 * 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 (slab_is_available() && (p < virt_to_phys(high_memory)) &&
	    !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) {
		printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
		       (unsigned long long)p, __builtin_return_address(0));
		return NULL;
	}
#endif

	if (size == 0)
		return NULL;

	/*
	 * Is it already mapped?  Perhaps overlapped by a previous
	 * mapping.
	 */
	v = p_block_mapped(p);
	if (v)
		goto out;

	if (slab_is_available()) {
		struct vm_struct *area;
		area = get_vm_area_caller(size, VM_IOREMAP, caller);
		if (area == 0)
			return NULL;
		area->phys_addr = p;
		v = (unsigned long) area->addr;
	} else {
		v = (ioremap_bot -= size);
	}

	/*
	 * 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 (slab_is_available())
			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_block_mapped((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)) &&
		       flags);
		set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
						     __pgprot(flags)));
	}
	smp_wmb();
	return err;
}

/*
 * Map in a chunk of physical memory starting at start.
 */
void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
{
	unsigned long v, s, f;
	phys_addr_t p;
	int ktext;

	s = offset;
	v = PAGE_OFFSET + s;
	p = memstart_addr + s;
	for (; s < top; s += PAGE_SIZE) {
		ktext = ((char *)v >= _stext && (char *)v < etext) ||
			((char *)v >= _sinittext && (char *)v < _einittext);
		f = ktext ? pgprot_val(PAGE_KERNEL_TEXT) : pgprot_val(PAGE_KERNEL);
		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;
	}
}

void __init mapin_ram(void)
{
	unsigned long s, top;

#ifndef CONFIG_WII
	top = total_lowmem;
	s = mmu_mapin_ram(top);
	__mapin_ram_chunk(s, top);
#else
	if (!wii_hole_size) {
		s = mmu_mapin_ram(total_lowmem);
		__mapin_ram_chunk(s, total_lowmem);
	} else {
		top = wii_hole_start;
		s = mmu_mapin_ram(top);
		__mapin_ram_chunk(s, top);

		top = memblock_end_of_DRAM();
		s = wii_mmu_mapin_mem2(top);
		__mapin_ram_chunk(s, top);
	}
#endif
}

/* 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_block_mapped(address))
		return 0;
	if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
		return -EINVAL;
	__set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
	wmb();
	flush_tlb_page(NULL, address);
	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 */

static int fixmaps;

void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
{
	unsigned long address = __fix_to_virt(idx);

	if (idx >= __end_of_fixed_addresses) {
		BUG();
		return;
	}

	map_page(address, phys, pgprot_val(flags));
	fixmaps++;
}

void __this_fixmap_does_not_exist(void)
{
	WARN_ON(1);
}
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>
95f72d1e	29	#include <linux/memblock.h>
5a0e3ad6	30	#include <linux/slab.h>
14cf11af PM	31
	32	#include <asm/pgtable.h>
	33	#include <asm/pgalloc.h>
2c419bde	34	#include <asm/fixmap.h>
14cf11af	35	#include <asm/io.h>
ae3a197e	36	#include <asm/setup.h>
14cf11af PM	37
	38	#include "mmu_decl.h"
	39
14cf11af	40	unsigned long ioremap_bot;
920573bd	41	EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
14cf11af	42
060ef9d8	43	extern char etext[], _stext[], _sinittext[], _einittext[];
14cf11af	44
bd721ea7	45	__ref pte_t pte_alloc_one_kernel(struct mm_struct mm, unsigned long address)
14cf11af PM	46	{
14cf11af PM	47	pte_t *pte;
14cf11af	48
f691fa10	49	if (slab_is_available()) {
32d6bd90	50	pte = (pte_t *)__get_free_page(GFP_KERNEL\|__GFP_ZERO);
14cf11af	51	} else {
10239733	52	pte = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
14cf11af PM	53	if (pte)
	54	clear_page(pte);
	55	}
	56	return pte;
	57	}
	58
2f569afd	59	pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
14cf11af PM	60	{
	61	struct page *ptepage;
	62
32d6bd90	63	gfp_t flags = GFP_KERNEL \| __GFP_ZERO;
14cf11af PM	64
14cf11af PM	65	ptepage = alloc_pages(flags, 0);
2f569afd MS	66	if (!ptepage)
2f569afd MS	67	return NULL;
4f804943 KS	68	if (!pgtable_page_ctor(ptepage)) {
	69	__free_page(ptepage);
	70	return NULL;
	71	}
14cf11af PM	72	return ptepage;
	73	}
	74
14cf11af PM	75	void __iomem *
	76	ioremap(phys_addr_t addr, unsigned long size)
	77	{
1cdab55d BH	78	return __ioremap_caller(addr, size, _PAGE_NO_CACHE \| _PAGE_GUARDED,
1cdab55d BH	79	__builtin_return_address(0));
14cf11af	80	}
920573bd	81	EXPORT_SYMBOL(ioremap);
14cf11af	82
be135f40 AB	83	void __iomem *
	84	ioremap_wc(phys_addr_t addr, unsigned long size)
	85	{
	86	return __ioremap_caller(addr, size, _PAGE_NO_CACHE,
	87	__builtin_return_address(0));
	88	}
	89	EXPORT_SYMBOL(ioremap_wc);
	90
68a64357	91	void __iomem *
40f1ce7f	92	ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
68a64357	93	{
a1f242ff	94	/* writeable implies dirty for kernel addresses */
a7b9f671	95	if ((flags & (_PAGE_RW \| _PAGE_RO)) != _PAGE_RO)
a1f242ff BH	96	flags \|= _PAGE_DIRTY \| _PAGE_HWWRITE;
	97
	98	/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
ea3cc330	99	flags &= ~(_PAGE_USER \| _PAGE_EXEC);
a1f242ff	100
55052eec BH	101	#ifdef _PAGE_BAP_SR
	102	/* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
	103	* which means that we just cleared supervisor access... oops ;-) This
	104	* restores it
	105	*/
	106	flags \|= _PAGE_BAP_SR;
	107	#endif
	108
1cdab55d	109	return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
68a64357	110	}
40f1ce7f	111	EXPORT_SYMBOL(ioremap_prot);
68a64357	112
14cf11af PM	113	void __iomem *
14cf11af PM	114	__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
1cdab55d BH	115	{
	116	return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
	117	}
	118
	119	void __iomem *
	120	__ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags,
	121	void *caller)
14cf11af PM	122	{
	123	unsigned long v, i;
	124	phys_addr_t p;
	125	int err;
	126
a1f242ff BH	127	/* Make sure we have the base flags */
a1f242ff BH	128	if ((flags & _PAGE_PRESENT) == 0)
4f9c53c8	129	flags \|= pgprot_val(PAGE_KERNEL);
a1f242ff BH	130
	131	/* Non-cacheable page cannot be coherent */
	132	if (flags & _PAGE_NO_CACHE)
	133	flags &= ~_PAGE_COHERENT;
	134
14cf11af PM	135	/*
	136	* Choose an address to map it to.
	137	* Once the vmalloc system is running, we use it.
e974cd4b	138	* Before then, we use space going down from IOREMAP_TOP
14cf11af PM	139	* (ioremap_bot records where we're up to).
	140	*/
	141	p = addr & PAGE_MASK;
	142	size = PAGE_ALIGN(addr + size) - p;
	143
	144	/*
	145	* If the address lies within the first 16 MB, assume it's in ISA
	146	* memory space
	147	*/
	148	if (p < 1610241024)
	149	p += _ISA_MEM_BASE;
	150
01695a96	151	#ifndef CONFIG_CRASH_DUMP
14cf11af PM	152	/*
	153	* Don't allow anybody to remap normal RAM that we're using.
	154	* mem_init() sets high_memory so only do the check after that.
	155	*/
f691fa10	156	if (slab_is_available() && (p < virt_to_phys(high_memory)) &&
95f72d1e	157	!(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) {
cc83458d	158	printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
37f01d64	159	(unsigned long long)p, __builtin_return_address(0));
14cf11af PM	160	return NULL;
14cf11af PM	161	}
01695a96	162	#endif
14cf11af PM	163
	164	if (size == 0)
	165	return NULL;
	166
	167	/*
	168	* Is it already mapped? Perhaps overlapped by a previous
3084cdb7	169	* mapping.
14cf11af	170	*/
3084cdb7 CL	171	v = p_block_mapped(p);
3084cdb7 CL	172	if (v)
14cf11af PM	173	goto out;
14cf11af PM	174
f691fa10	175	if (slab_is_available()) {
14cf11af	176	struct vm_struct *area;
1cdab55d	177	area = get_vm_area_caller(size, VM_IOREMAP, caller);
14cf11af PM	178	if (area == 0)
14cf11af PM	179	return NULL;
7a9d1256	180	area->phys_addr = p;
14cf11af PM	181	v = (unsigned long) area->addr;
	182	} else {
	183	v = (ioremap_bot -= size);
	184	}
	185
14cf11af PM	186	/*
	187	* Should check if it is a candidate for a BAT mapping
	188	*/
	189
	190	err = 0;
	191	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
	192	err = map_page(v+i, p+i, flags);
	193	if (err) {
f691fa10	194	if (slab_is_available())
14cf11af PM	195	vunmap((void *)v);
	196	return NULL;
	197	}
	198
	199	out:
	200	return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
	201	}
920573bd	202	EXPORT_SYMBOL(__ioremap);
14cf11af PM	203
	204	void iounmap(volatile void __iomem *addr)
	205	{
	206	/*
	207	* If mapped by BATs then there is nothing to do.
	208	* Calling vfree() generates a benign warning.
	209	*/
3084cdb7 CL	210	if (v_block_mapped((unsigned long)addr))
3084cdb7 CL	211	return;
14cf11af PM	212
	213	if (addr > high_memory && (unsigned long) addr < ioremap_bot)
	214	vunmap((void *) (PAGE_MASK & (unsigned long)addr));
	215	}
920573bd	216	EXPORT_SYMBOL(iounmap);
14cf11af	217
68a64357	218	int map_page(unsigned long va, phys_addr_t pa, int flags)
14cf11af PM	219	{
	220	pmd_t *pd;
	221	pte_t *pg;
	222	int err = -ENOMEM;
	223
14cf11af	224	/* Use upper 10 bits of VA to index the first level map */
d1953c88	225	pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
14cf11af	226	/* Use middle 10 bits of VA to index the second-level map */
e2f2e58e	227	pg = pte_alloc_kernel(pd, va);
14cf11af PM	228	if (pg != 0) {
14cf11af PM	229	err = 0;
3be4e699 BH	230	/* The PTE should never be already set nor present in the
	231	* hash table
	232	*/
7021d86a AV	233	BUG_ON((pte_val(*pg) & (_PAGE_PRESENT \| _PAGE_HASHPTE)) &&
7021d86a AV	234	flags);
3be4e699 BH	235	set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
3be4e699 BH	236	__pgprot(flags)));
14cf11af	237	}
47ce8af4	238	smp_wmb();
14cf11af PM	239	return err;
	240	}
	241
	242	/*
de32400d	243	* Map in a chunk of physical memory starting at start.
14cf11af	244	*/
de32400d	245	void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
14cf11af	246	{
99c62dd7 KG	247	unsigned long v, s, f;
99c62dd7 KG	248	phys_addr_t p;
ee4f2ea4	249	int ktext;
14cf11af	250
de32400d	251	s = offset;
ccdcef72	252	v = PAGE_OFFSET + s;
99c62dd7	253	p = memstart_addr + s;
de32400d	254	for (; s < top; s += PAGE_SIZE) {
060ef9d8 CL	255	ktext = ((char )v >= _stext && (char )v < etext) \|\|
060ef9d8 CL	256	((char )v >= _sinittext && (char )v < _einittext);
4f9c53c8	257	f = ktext ? pgprot_val(PAGE_KERNEL_TEXT) : pgprot_val(PAGE_KERNEL);
14cf11af	258	map_page(v, p, f);
ee4f2ea4 BH	259	#ifdef CONFIG_PPC_STD_MMU_32
	260	if (ktext)
	261	hash_preload(&init_mm, v, 0, 0x300);
	262	#endif
14cf11af PM	263	v += PAGE_SIZE;
	264	p += PAGE_SIZE;
	265	}
	266	}
	267
de32400d AH	268	void __init mapin_ram(void)
	269	{
	270	unsigned long s, top;
	271
	272	#ifndef CONFIG_WII
	273	top = total_lowmem;
	274	s = mmu_mapin_ram(top);
	275	__mapin_ram_chunk(s, top);
	276	#else
	277	if (!wii_hole_size) {
	278	s = mmu_mapin_ram(total_lowmem);
	279	__mapin_ram_chunk(s, total_lowmem);
	280	} else {
	281	top = wii_hole_start;
	282	s = mmu_mapin_ram(top);
	283	__mapin_ram_chunk(s, top);
	284
95f72d1e	285	top = memblock_end_of_DRAM();
de32400d AH	286	s = wii_mmu_mapin_mem2(top);
	287	__mapin_ram_chunk(s, top);
	288	}
	289	#endif
	290	}
	291
14cf11af PM	292	/* Scan the real Linux page tables and return a PTE pointer for
	293	* a virtual address in a context.
	294	* Returns true (1) if PTE was found, zero otherwise. The pointer to
	295	* the PTE pointer is unmodified if PTE is not found.
	296	*/
	297	int
bab70a4a	298	get_pteptr(struct mm_struct mm, unsigned long addr, pte_t ptep, pmd_t *pmdp)
14cf11af PM	299	{
14cf11af PM	300	pgd_t *pgd;
d1953c88	301	pud_t *pud;
14cf11af PM	302	pmd_t *pmd;
	303	pte_t *pte;
	304	int retval = 0;
	305
	306	pgd = pgd_offset(mm, addr & PAGE_MASK);
	307	if (pgd) {
d1953c88 DG	308	pud = pud_offset(pgd, addr & PAGE_MASK);
	309	if (pud && pud_present(*pud)) {
	310	pmd = pmd_offset(pud, addr & PAGE_MASK);
	311	if (pmd_present(*pmd)) {
	312	pte = pte_offset_map(pmd, addr & PAGE_MASK);
	313	if (pte) {
	314	retval = 1;
	315	*ptep = pte;
	316	if (pmdp)
	317	*pmdp = pmd;
	318	/* XXX caller needs to do pte_unmap, yuck */
	319	}
	320	}
	321	}
14cf11af PM	322	}
	323	return(retval);
	324	}
	325
88df6e90 BH	326	#ifdef CONFIG_DEBUG_PAGEALLOC
	327
	328	static int __change_page_attr(struct page *page, pgprot_t prot)
	329	{
	330	pte_t *kpte;
	331	pmd_t *kpmd;
	332	unsigned long address;
	333
	334	BUG_ON(PageHighMem(page));
	335	address = (unsigned long)page_address(page);
	336
3084cdb7	337	if (v_block_mapped(address))
88df6e90 BH	338	return 0;
	339	if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
	340	return -EINVAL;
50891457	341	__set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
88df6e90	342	wmb();
f63837f0	343	flush_tlb_page(NULL, address);
88df6e90 BH	344	pte_unmap(kpte);
	345
	346	return 0;
	347	}
	348
	349	/*
	350	* Change the page attributes of an page in the linear mapping.
	351	*
	352	* THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
	353	*/
	354	static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
	355	{
	356	int i, err = 0;
	357	unsigned long flags;
	358
	359	local_irq_save(flags);
	360	for (i = 0; i < numpages; i++, page++) {
	361	err = __change_page_attr(page, prot);
	362	if (err)
	363	break;
	364	}
	365	local_irq_restore(flags);
	366	return err;
	367	}
	368
	369
031bc574	370	void __kernel_map_pages(struct page *page, int numpages, int enable)
88df6e90 BH	371	{
	372	if (PageHighMem(page))
	373	return;
	374
	375	change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
	376	}
	377	#endif /* CONFIG_DEBUG_PAGEALLOC */
2c419bde KG	378
2c419bde KG	379	static int fixmaps;
2c419bde KG	380
	381	void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
	382	{
	383	unsigned long address = __fix_to_virt(idx);
	384
	385	if (idx >= __end_of_fixed_addresses) {
	386	BUG();
	387	return;
	388	}
	389
46a74179	390	map_page(address, phys, pgprot_val(flags));
2c419bde KG	391	fixmaps++;
	392	}
	393
	394	void __this_fixmap_does_not_exist(void)
	395	{
	396	WARN_ON(1);
	397	}