[linux-2.6-block.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 <asm/sections.h>

#include <mm/mmu_decl.h>

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

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

void __iomem *
ioremap(phys_addr_t addr, unsigned long size)
{
	pgprot_t prot = pgprot_noncached(PAGE_KERNEL);

	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap);

void __iomem *
ioremap_wc(phys_addr_t addr, unsigned long size)
{
	pgprot_t prot = pgprot_noncached_wc(PAGE_KERNEL);

	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_wc);

void __iomem *
ioremap_wt(phys_addr_t addr, unsigned long size)
{
	pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);

	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_wt);

void __iomem *
ioremap_coherent(phys_addr_t addr, unsigned long size)
{
	pgprot_t prot = pgprot_cached(PAGE_KERNEL);

	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_coherent);

void __iomem *
ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
{
	pte_t pte = __pte(flags);

	/* writeable implies dirty for kernel addresses */
	if (pte_write(pte))
		pte = pte_mkdirty(pte);

	/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
	pte = pte_exprotect(pte);
	pte = pte_mkprivileged(pte);

	return __ioremap_caller(addr, size, pte_pgprot(pte), __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, __pgprot(flags), __builtin_return_address(0));
}

void __iomem *
__ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
{
	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_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 - 1) &&
	    page_is_ram(__phys_to_pfn(p))) {
		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_kernel_page(v + i, p + i, prot);
	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);

static void __init *early_alloc_pgtable(unsigned long size)
{
	void *ptr = memblock_alloc(size, size);

	if (!ptr)
		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
		      __func__, size, size);

	return ptr;
}

static pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va)
{
	if (pmd_none(*pmdp)) {
		pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);

		pmd_populate_kernel(&init_mm, pmdp, ptep);
	}
	return pte_offset_kernel(pmdp, va);
}


int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
{
	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 */
	if (likely(slab_is_available()))
		pg = pte_alloc_kernel(pd, va);
	else
		pg = early_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_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot));
		set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
	}
	smp_wmb();
	return err;
}

/*
 * Map in a chunk of physical memory starting at start.
 */
static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
{
	unsigned long v, s;
	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);
		map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
#ifdef CONFIG_PPC_BOOK3S_32
		if (ktext)
			hash_preload(&init_mm, v, false, 0x300);
#endif
		v += PAGE_SIZE;
		p += PAGE_SIZE;
	}
}

void __init mapin_ram(void)
{
	struct memblock_region *reg;

	for_each_memblock(memory, reg) {
		phys_addr_t base = reg->base;
		phys_addr_t top = min(base + reg->size, total_lowmem);

		if (base >= top)
			continue;
		base = mmu_mapin_ram(base, top);
		if (IS_ENABLED(CONFIG_BDI_SWITCH))
			__mapin_ram_chunk(reg->base, top);
		else
			__mapin_ram_chunk(base, top);
	}
}

/* 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.
 */
static 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);
}

static int __change_page_attr_noflush(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);
	pte_unmap(kpte);

	return 0;
}

/*
 * Change the page attributes of an page in the linear mapping.
 *
 * THIS DOES NOTHING 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;
	struct page *start = page;

	local_irq_save(flags);
	for (i = 0; i < numpages; i++, page++) {
		err = __change_page_attr_noflush(page, prot);
		if (err)
			break;
	}
	wmb();
	local_irq_restore(flags);
	flush_tlb_kernel_range((unsigned long)page_address(start),
			       (unsigned long)page_address(page));
	return err;
}

void mark_initmem_nx(void)
{
	struct page *page = virt_to_page(_sinittext);
	unsigned long numpages = PFN_UP((unsigned long)_einittext) -
				 PFN_DOWN((unsigned long)_sinittext);

	if (v_block_mapped((unsigned long)_stext) + 1)
		mmu_mark_initmem_nx();
	else
		change_page_attr(page, numpages, PAGE_KERNEL);
}

#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void)
{
	struct page *page;
	unsigned long numpages;

	if (v_block_mapped((unsigned long)_sinittext)) {
		mmu_mark_rodata_ro();
		return;
	}

	page = virt_to_page(_stext);
	numpages = PFN_UP((unsigned long)_etext) -
		   PFN_DOWN((unsigned long)_stext);

	change_page_attr(page, numpages, PAGE_KERNEL_ROX);
	/*
	 * mark .rodata as read only. Use __init_begin rather than __end_rodata
	 * to cover NOTES and EXCEPTION_TABLE.
	 */
	page = virt_to_page(__start_rodata);
	numpages = PFN_UP((unsigned long)__init_begin) -
		   PFN_DOWN((unsigned long)__start_rodata);

	change_page_attr(page, numpages, PAGE_KERNEL_RO);

	// mark_initmem_nx() should have already run by now
	ptdump_check_wx();
}
#endif

#ifdef CONFIG_DEBUG_PAGEALLOC
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>
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>
95902e6c	37	#include <asm/sections.h>
14cf11af	38
9d9f2ccc	39	#include <mm/mmu_decl.h>
14cf11af	40
14cf11af	41	unsigned long ioremap_bot;
920573bd	42	EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
14cf11af	43
060ef9d8	44	extern char etext[], _stext[], _sinittext[], _einittext[];
14cf11af	45
14cf11af PM	46	void __iomem *
	47	ioremap(phys_addr_t addr, unsigned long size)
	48	{
c766ee72	49	pgprot_t prot = pgprot_noncached(PAGE_KERNEL);
56f3c141	50
c766ee72	51	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
14cf11af	52	}
920573bd	53	EXPORT_SYMBOL(ioremap);
14cf11af	54
be135f40 AB	55	void __iomem *
	56	ioremap_wc(phys_addr_t addr, unsigned long size)
	57	{
c766ee72	58	pgprot_t prot = pgprot_noncached_wc(PAGE_KERNEL);
56f3c141	59
c766ee72	60	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
be135f40 AB	61	}
	62	EXPORT_SYMBOL(ioremap_wc);
	63
86c391bd CL	64	void __iomem *
	65	ioremap_wt(phys_addr_t addr, unsigned long size)
	66	{
c766ee72	67	pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);
56f3c141	68
c766ee72	69	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
86c391bd CL	70	}
	71	EXPORT_SYMBOL(ioremap_wt);
	72
	73	void __iomem *
	74	ioremap_coherent(phys_addr_t addr, unsigned long size)
	75	{
c766ee72	76	pgprot_t prot = pgprot_cached(PAGE_KERNEL);
56f3c141	77
c766ee72	78	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
86c391bd CL	79	}
	80	EXPORT_SYMBOL(ioremap_coherent);
	81
68a64357	82	void __iomem *
40f1ce7f	83	ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
68a64357	84	{
26973fa5 CL	85	pte_t pte = __pte(flags);
26973fa5 CL	86
a1f242ff	87	/* writeable implies dirty for kernel addresses */
26973fa5 CL	88	if (pte_write(pte))
26973fa5 CL	89	pte = pte_mkdirty(pte);
a1f242ff BH	90
a1f242ff BH	91	/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
26973fa5 CL	92	pte = pte_exprotect(pte);
26973fa5 CL	93	pte = pte_mkprivileged(pte);
55052eec	94
26973fa5	95	return __ioremap_caller(addr, size, pte_pgprot(pte), __builtin_return_address(0));
68a64357	96	}
40f1ce7f	97	EXPORT_SYMBOL(ioremap_prot);
68a64357	98
14cf11af PM	99	void __iomem *
14cf11af PM	100	__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
1cdab55d	101	{
c766ee72	102	return __ioremap_caller(addr, size, __pgprot(flags), __builtin_return_address(0));
1cdab55d BH	103	}
	104
	105	void __iomem *
c766ee72	106	__ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
14cf11af PM	107	{
	108	unsigned long v, i;
	109	phys_addr_t p;
	110	int err;
	111
	112	/*
	113	* Choose an address to map it to.
	114	* Once the vmalloc system is running, we use it.
e974cd4b	115	* Before then, we use space going down from IOREMAP_TOP
14cf11af PM	116	* (ioremap_bot records where we're up to).
	117	*/
	118	p = addr & PAGE_MASK;
	119	size = PAGE_ALIGN(addr + size) - p;
	120
	121	/*
	122	* If the address lies within the first 16 MB, assume it's in ISA
	123	* memory space
	124	*/
	125	if (p < 1610241024)
	126	p += _ISA_MEM_BASE;
	127
01695a96	128	#ifndef CONFIG_CRASH_DUMP
14cf11af PM	129	/*
	130	* Don't allow anybody to remap normal RAM that we're using.
	131	* mem_init() sets high_memory so only do the check after that.
	132	*/
6bf752da	133	if (slab_is_available() && p <= virt_to_phys(high_memory - 1) &&
7e140591	134	page_is_ram(__phys_to_pfn(p))) {
cc83458d	135	printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
37f01d64	136	(unsigned long long)p, __builtin_return_address(0));
14cf11af PM	137	return NULL;
14cf11af PM	138	}
01695a96	139	#endif
14cf11af PM	140
	141	if (size == 0)
	142	return NULL;
	143
	144	/*
	145	* Is it already mapped? Perhaps overlapped by a previous
3084cdb7	146	* mapping.
14cf11af	147	*/
3084cdb7 CL	148	v = p_block_mapped(p);
3084cdb7 CL	149	if (v)
14cf11af PM	150	goto out;
14cf11af PM	151
f691fa10	152	if (slab_is_available()) {
14cf11af	153	struct vm_struct *area;
1cdab55d	154	area = get_vm_area_caller(size, VM_IOREMAP, caller);
14cf11af PM	155	if (area == 0)
14cf11af PM	156	return NULL;
7a9d1256	157	area->phys_addr = p;
14cf11af PM	158	v = (unsigned long) area->addr;
	159	} else {
	160	v = (ioremap_bot -= size);
	161	}
	162
14cf11af PM	163	/*
	164	* Should check if it is a candidate for a BAT mapping
	165	*/
	166
	167	err = 0;
	168	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
c766ee72	169	err = map_kernel_page(v + i, p + i, prot);
14cf11af	170	if (err) {
f691fa10	171	if (slab_is_available())
14cf11af PM	172	vunmap((void *)v);
	173	return NULL;
	174	}
	175
	176	out:
	177	return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
	178	}
920573bd	179	EXPORT_SYMBOL(__ioremap);
14cf11af PM	180
	181	void iounmap(volatile void __iomem *addr)
	182	{
	183	/*
	184	* If mapped by BATs then there is nothing to do.
	185	* Calling vfree() generates a benign warning.
	186	*/
3084cdb7 CL	187	if (v_block_mapped((unsigned long)addr))
3084cdb7 CL	188	return;
14cf11af PM	189
	190	if (addr > high_memory && (unsigned long) addr < ioremap_bot)
	191	vunmap((void *) (PAGE_MASK & (unsigned long)addr));
	192	}
920573bd	193	EXPORT_SYMBOL(iounmap);
14cf11af	194
4a6d8cf9 CL	195	static void __init *early_alloc_pgtable(unsigned long size)
	196	{
	197	void *ptr = memblock_alloc(size, size);
	198
	199	if (!ptr)
	200	panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
	201	__func__, size, size);
	202
	203	return ptr;
	204	}
	205
	206	static pte_t __init early_pte_alloc_kernel(pmd_t pmdp, unsigned long va)
	207	{
	208	if (pmd_none(*pmdp)) {
	209	pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
	210
	211	pmd_populate_kernel(&init_mm, pmdp, ptep);
	212	}
	213	return pte_offset_kernel(pmdp, va);
	214	}
	215
	216
	217	int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
14cf11af PM	218	{
	219	pmd_t *pd;
	220	pte_t *pg;
	221	int err = -ENOMEM;
	222
14cf11af	223	/* Use upper 10 bits of VA to index the first level map */
d1953c88	224	pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
14cf11af	225	/* Use middle 10 bits of VA to index the second-level map */
4a6d8cf9 CL	226	if (likely(slab_is_available()))
	227	pg = pte_alloc_kernel(pd, va);
	228	else
	229	pg = early_pte_alloc_kernel(pd, va);
14cf11af PM	230	if (pg != 0) {
14cf11af PM	231	err = 0;
3be4e699 BH	232	/* The PTE should never be already set nor present in the
	233	* hash table
	234	*/
26973fa5	235	BUG_ON((pte_present(pg) \| pte_hashpte(pg)) && pgprot_val(prot));
c766ee72	236	set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
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	*/
86b19520	245	static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
14cf11af	246	{
c766ee72	247	unsigned long v, s;
99c62dd7	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);
c766ee72	257	map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
68289ae9	258	#ifdef CONFIG_PPC_BOOK3S_32
ee4f2ea4	259	if (ktext)
34eb138e	260	hash_preload(&init_mm, v, false, 0x300);
ee4f2ea4	261	#endif
14cf11af PM	262	v += PAGE_SIZE;
	263	p += PAGE_SIZE;
	264	}
	265	}
	266
de32400d AH	267	void __init mapin_ram(void)
de32400d AH	268	{
9e849f23 CL	269	struct memblock_region *reg;
	270
	271	for_each_memblock(memory, reg) {
	272	phys_addr_t base = reg->base;
	273	phys_addr_t top = min(base + reg->size, total_lowmem);
de32400d	274
9e849f23 CL	275	if (base >= top)
	276	continue;
	277	base = mmu_mapin_ram(base, top);
d2f15e09 CL	278	if (IS_ENABLED(CONFIG_BDI_SWITCH))
	279	__mapin_ram_chunk(reg->base, top);
	280	else
	281	__mapin_ram_chunk(base, top);
de32400d	282	}
de32400d AH	283	}
de32400d AH	284
14cf11af PM	285	/* Scan the real Linux page tables and return a PTE pointer for
	286	* a virtual address in a context.
	287	* Returns true (1) if PTE was found, zero otherwise. The pointer to
	288	* the PTE pointer is unmodified if PTE is not found.
	289	*/
86b19520	290	static int
bab70a4a	291	get_pteptr(struct mm_struct mm, unsigned long addr, pte_t ptep, pmd_t *pmdp)
14cf11af PM	292	{
14cf11af PM	293	pgd_t *pgd;
d1953c88	294	pud_t *pud;
14cf11af PM	295	pmd_t *pmd;
	296	pte_t *pte;
	297	int retval = 0;
	298
	299	pgd = pgd_offset(mm, addr & PAGE_MASK);
	300	if (pgd) {
d1953c88 DG	301	pud = pud_offset(pgd, addr & PAGE_MASK);
	302	if (pud && pud_present(*pud)) {
	303	pmd = pmd_offset(pud, addr & PAGE_MASK);
	304	if (pmd_present(*pmd)) {
	305	pte = pte_offset_map(pmd, addr & PAGE_MASK);
	306	if (pte) {
	307	retval = 1;
	308	*ptep = pte;
	309	if (pmdp)
	310	*pmdp = pmd;
	311	/* XXX caller needs to do pte_unmap, yuck */
	312	}
	313	}
	314	}
14cf11af PM	315	}
	316	return(retval);
	317	}
	318
e611939f	319	static int __change_page_attr_noflush(struct page *page, pgprot_t prot)
88df6e90 BH	320	{
	321	pte_t *kpte;
	322	pmd_t *kpmd;
	323	unsigned long address;
	324
	325	BUG_ON(PageHighMem(page));
	326	address = (unsigned long)page_address(page);
	327
3084cdb7	328	if (v_block_mapped(address))
88df6e90 BH	329	return 0;
	330	if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
	331	return -EINVAL;
50891457	332	__set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
88df6e90 BH	333	pte_unmap(kpte);
	334
	335	return 0;
	336	}
	337
	338	/*
	339	* Change the page attributes of an page in the linear mapping.
	340	*
3184cc4b	341	* THIS DOES NOTHING WITH BAT MAPPINGS, DEBUG USE ONLY
88df6e90 BH	342	*/
	343	static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
	344	{
	345	int i, err = 0;
	346	unsigned long flags;
e611939f	347	struct page *start = page;
88df6e90 BH	348
	349	local_irq_save(flags);
	350	for (i = 0; i < numpages; i++, page++) {
e611939f	351	err = __change_page_attr_noflush(page, prot);
88df6e90 BH	352	if (err)
	353	break;
	354	}
e611939f	355	wmb();
7c6a4f3b	356	local_irq_restore(flags);
e611939f CL	357	flush_tlb_kernel_range((unsigned long)page_address(start),
e611939f CL	358	(unsigned long)page_address(page));
88df6e90 BH	359	return err;
	360	}
	361
3184cc4b CL	362	void mark_initmem_nx(void)
	363	{
	364	struct page *page = virt_to_page(_sinittext);
	365	unsigned long numpages = PFN_UP((unsigned long)_einittext) -
	366	PFN_DOWN((unsigned long)_sinittext);
	367
63b2bc61 CL	368	if (v_block_mapped((unsigned long)_stext) + 1)
	369	mmu_mark_initmem_nx();
	370	else
	371	change_page_attr(page, numpages, PAGE_KERNEL);
3184cc4b	372	}
88df6e90	373
95902e6c CL	374	#ifdef CONFIG_STRICT_KERNEL_RWX
	375	void mark_rodata_ro(void)
	376	{
	377	struct page *page;
	378	unsigned long numpages;
	379
63b2bc61 CL	380	if (v_block_mapped((unsigned long)_sinittext)) {
	381	mmu_mark_rodata_ro();
	382	return;
	383	}
	384
95902e6c CL	385	page = virt_to_page(_stext);
	386	numpages = PFN_UP((unsigned long)_etext) -
	387	PFN_DOWN((unsigned long)_stext);
	388
	389	change_page_attr(page, numpages, PAGE_KERNEL_ROX);
	390	/*
	391	* mark .rodata as read only. Use __init_begin rather than __end_rodata
	392	* to cover NOTES and EXCEPTION_TABLE.
	393	*/
	394	page = virt_to_page(__start_rodata);
	395	numpages = PFN_UP((unsigned long)__init_begin) -
	396	PFN_DOWN((unsigned long)__start_rodata);
	397
	398	change_page_attr(page, numpages, PAGE_KERNEL_RO);
453d87f6 RC	399
	400	// mark_initmem_nx() should have already run by now
	401	ptdump_check_wx();
95902e6c CL	402	}
	403	#endif
	404
3184cc4b	405	#ifdef CONFIG_DEBUG_PAGEALLOC
031bc574	406	void __kernel_map_pages(struct page *page, int numpages, int enable)
88df6e90 BH	407	{
	408	if (PageHighMem(page))
	409	return;
	410
	411	change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
	412	}
	413	#endif /* CONFIG_DEBUG_PAGEALLOC */