[mirror_ubuntu-jammy-kernel.git] / arch / powerpc / mm / pgtable_32.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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
 */

#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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
14cf11af PM	2	/*
	3	* This file contains the routines setting up the linux page tables.
	4	* -- paulus
	5	*
	6	* Derived from arch/ppc/mm/init.c:
	7	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	8	*
	9	* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
	10	* and Cort Dougan (PReP) (cort@cs.nmt.edu)
	11	* Copyright (C) 1996 Paul Mackerras
14cf11af PM	12	*
	13	* Derived from "arch/i386/mm/init.c"
	14	* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
14cf11af PM	15	*/
14cf11af PM	16
14cf11af PM	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/types.h>
	20	#include <linux/mm.h>
	21	#include <linux/vmalloc.h>
	22	#include <linux/init.h>
	23	#include <linux/highmem.h>
95f72d1e	24	#include <linux/memblock.h>
5a0e3ad6	25	#include <linux/slab.h>
14cf11af PM	26
	27	#include <asm/pgtable.h>
	28	#include <asm/pgalloc.h>
2c419bde	29	#include <asm/fixmap.h>
14cf11af	30	#include <asm/io.h>
ae3a197e	31	#include <asm/setup.h>
95902e6c	32	#include <asm/sections.h>
14cf11af	33
9d9f2ccc	34	#include <mm/mmu_decl.h>
14cf11af	35
14cf11af	36	unsigned long ioremap_bot;
920573bd	37	EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
14cf11af	38
060ef9d8	39	extern char etext[], _stext[], _sinittext[], _einittext[];
14cf11af	40
14cf11af PM	41	void __iomem *
	42	ioremap(phys_addr_t addr, unsigned long size)
	43	{
c766ee72	44	pgprot_t prot = pgprot_noncached(PAGE_KERNEL);
56f3c141	45
c766ee72	46	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
14cf11af	47	}
920573bd	48	EXPORT_SYMBOL(ioremap);
14cf11af	49
be135f40 AB	50	void __iomem *
	51	ioremap_wc(phys_addr_t addr, unsigned long size)
	52	{
c766ee72	53	pgprot_t prot = pgprot_noncached_wc(PAGE_KERNEL);
56f3c141	54
c766ee72	55	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
be135f40 AB	56	}
	57	EXPORT_SYMBOL(ioremap_wc);
	58
86c391bd CL	59	void __iomem *
	60	ioremap_wt(phys_addr_t addr, unsigned long size)
	61	{
c766ee72	62	pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);
56f3c141	63
c766ee72	64	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
86c391bd CL	65	}
	66	EXPORT_SYMBOL(ioremap_wt);
	67
	68	void __iomem *
	69	ioremap_coherent(phys_addr_t addr, unsigned long size)
	70	{
c766ee72	71	pgprot_t prot = pgprot_cached(PAGE_KERNEL);
56f3c141	72
c766ee72	73	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
86c391bd CL	74	}
	75	EXPORT_SYMBOL(ioremap_coherent);
	76
68a64357	77	void __iomem *
40f1ce7f	78	ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
68a64357	79	{
26973fa5 CL	80	pte_t pte = __pte(flags);
26973fa5 CL	81
a1f242ff	82	/* writeable implies dirty for kernel addresses */
26973fa5 CL	83	if (pte_write(pte))
26973fa5 CL	84	pte = pte_mkdirty(pte);
a1f242ff BH	85
a1f242ff BH	86	/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
26973fa5 CL	87	pte = pte_exprotect(pte);
26973fa5 CL	88	pte = pte_mkprivileged(pte);
55052eec	89
26973fa5	90	return __ioremap_caller(addr, size, pte_pgprot(pte), __builtin_return_address(0));
68a64357	91	}
40f1ce7f	92	EXPORT_SYMBOL(ioremap_prot);
68a64357	93
14cf11af PM	94	void __iomem *
14cf11af PM	95	__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
1cdab55d	96	{
c766ee72	97	return __ioremap_caller(addr, size, __pgprot(flags), __builtin_return_address(0));
1cdab55d BH	98	}
	99
	100	void __iomem *
c766ee72	101	__ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
14cf11af PM	102	{
	103	unsigned long v, i;
	104	phys_addr_t p;
	105	int err;
	106
	107	/*
	108	* Choose an address to map it to.
	109	* Once the vmalloc system is running, we use it.
e974cd4b	110	* Before then, we use space going down from IOREMAP_TOP
14cf11af PM	111	* (ioremap_bot records where we're up to).
	112	*/
	113	p = addr & PAGE_MASK;
	114	size = PAGE_ALIGN(addr + size) - p;
	115
	116	/*
	117	* If the address lies within the first 16 MB, assume it's in ISA
	118	* memory space
	119	*/
	120	if (p < 1610241024)
	121	p += _ISA_MEM_BASE;
	122
01695a96	123	#ifndef CONFIG_CRASH_DUMP
14cf11af PM	124	/*
	125	* Don't allow anybody to remap normal RAM that we're using.
	126	* mem_init() sets high_memory so only do the check after that.
	127	*/
6bf752da	128	if (slab_is_available() && p <= virt_to_phys(high_memory - 1) &&
7e140591	129	page_is_ram(__phys_to_pfn(p))) {
cc83458d	130	printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
37f01d64	131	(unsigned long long)p, __builtin_return_address(0));
14cf11af PM	132	return NULL;
14cf11af PM	133	}
01695a96	134	#endif
14cf11af PM	135
	136	if (size == 0)
	137	return NULL;
	138
	139	/*
	140	* Is it already mapped? Perhaps overlapped by a previous
3084cdb7	141	* mapping.
14cf11af	142	*/
3084cdb7 CL	143	v = p_block_mapped(p);
3084cdb7 CL	144	if (v)
14cf11af PM	145	goto out;
14cf11af PM	146
f691fa10	147	if (slab_is_available()) {
14cf11af	148	struct vm_struct *area;
1cdab55d	149	area = get_vm_area_caller(size, VM_IOREMAP, caller);
14cf11af PM	150	if (area == 0)
14cf11af PM	151	return NULL;
7a9d1256	152	area->phys_addr = p;
14cf11af PM	153	v = (unsigned long) area->addr;
	154	} else {
	155	v = (ioremap_bot -= size);
	156	}
	157
14cf11af PM	158	/*
	159	* Should check if it is a candidate for a BAT mapping
	160	*/
	161
	162	err = 0;
	163	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
c766ee72	164	err = map_kernel_page(v + i, p + i, prot);
14cf11af	165	if (err) {
f691fa10	166	if (slab_is_available())
14cf11af PM	167	vunmap((void *)v);
	168	return NULL;
	169	}
	170
	171	out:
	172	return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
	173	}
920573bd	174	EXPORT_SYMBOL(__ioremap);
14cf11af PM	175
	176	void iounmap(volatile void __iomem *addr)
	177	{
	178	/*
	179	* If mapped by BATs then there is nothing to do.
	180	* Calling vfree() generates a benign warning.
	181	*/
3084cdb7 CL	182	if (v_block_mapped((unsigned long)addr))
3084cdb7 CL	183	return;
14cf11af PM	184
	185	if (addr > high_memory && (unsigned long) addr < ioremap_bot)
	186	vunmap((void *) (PAGE_MASK & (unsigned long)addr));
	187	}
920573bd	188	EXPORT_SYMBOL(iounmap);
14cf11af	189
4a6d8cf9 CL	190	static void __init *early_alloc_pgtable(unsigned long size)
	191	{
	192	void *ptr = memblock_alloc(size, size);
	193
	194	if (!ptr)
	195	panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
	196	__func__, size, size);
	197
	198	return ptr;
	199	}
	200
	201	static pte_t __init early_pte_alloc_kernel(pmd_t pmdp, unsigned long va)
	202	{
	203	if (pmd_none(*pmdp)) {
	204	pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
	205
	206	pmd_populate_kernel(&init_mm, pmdp, ptep);
	207	}
	208	return pte_offset_kernel(pmdp, va);
	209	}
	210
	211
	212	int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
14cf11af PM	213	{
	214	pmd_t *pd;
	215	pte_t *pg;
	216	int err = -ENOMEM;
	217
14cf11af	218	/* Use upper 10 bits of VA to index the first level map */
d1953c88	219	pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
14cf11af	220	/* Use middle 10 bits of VA to index the second-level map */
4a6d8cf9 CL	221	if (likely(slab_is_available()))
	222	pg = pte_alloc_kernel(pd, va);
	223	else
	224	pg = early_pte_alloc_kernel(pd, va);
14cf11af PM	225	if (pg != 0) {
14cf11af PM	226	err = 0;
3be4e699 BH	227	/* The PTE should never be already set nor present in the
	228	* hash table
	229	*/
26973fa5	230	BUG_ON((pte_present(pg) \| pte_hashpte(pg)) && pgprot_val(prot));
c766ee72	231	set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
14cf11af	232	}
47ce8af4	233	smp_wmb();
14cf11af PM	234	return err;
	235	}
	236
	237	/*
de32400d	238	* Map in a chunk of physical memory starting at start.
14cf11af	239	*/
86b19520	240	static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
14cf11af	241	{
c766ee72	242	unsigned long v, s;
99c62dd7	243	phys_addr_t p;
ee4f2ea4	244	int ktext;
14cf11af	245
de32400d	246	s = offset;
ccdcef72	247	v = PAGE_OFFSET + s;
99c62dd7	248	p = memstart_addr + s;
de32400d	249	for (; s < top; s += PAGE_SIZE) {
060ef9d8 CL	250	ktext = ((char )v >= _stext && (char )v < etext) \|\|
060ef9d8 CL	251	((char )v >= _sinittext && (char )v < _einittext);
c766ee72	252	map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
68289ae9	253	#ifdef CONFIG_PPC_BOOK3S_32
ee4f2ea4	254	if (ktext)
34eb138e	255	hash_preload(&init_mm, v, false, 0x300);
ee4f2ea4	256	#endif
14cf11af PM	257	v += PAGE_SIZE;
	258	p += PAGE_SIZE;
	259	}
	260	}
	261
de32400d AH	262	void __init mapin_ram(void)
de32400d AH	263	{
9e849f23 CL	264	struct memblock_region *reg;
	265
	266	for_each_memblock(memory, reg) {
	267	phys_addr_t base = reg->base;
	268	phys_addr_t top = min(base + reg->size, total_lowmem);
de32400d	269
9e849f23 CL	270	if (base >= top)
	271	continue;
	272	base = mmu_mapin_ram(base, top);
d2f15e09 CL	273	if (IS_ENABLED(CONFIG_BDI_SWITCH))
	274	__mapin_ram_chunk(reg->base, top);
	275	else
	276	__mapin_ram_chunk(base, top);
de32400d	277	}
de32400d AH	278	}
de32400d AH	279
14cf11af PM	280	/* Scan the real Linux page tables and return a PTE pointer for
	281	* a virtual address in a context.
	282	* Returns true (1) if PTE was found, zero otherwise. The pointer to
	283	* the PTE pointer is unmodified if PTE is not found.
	284	*/
86b19520	285	static int
bab70a4a	286	get_pteptr(struct mm_struct mm, unsigned long addr, pte_t ptep, pmd_t *pmdp)
14cf11af PM	287	{
14cf11af PM	288	pgd_t *pgd;
d1953c88	289	pud_t *pud;
14cf11af PM	290	pmd_t *pmd;
	291	pte_t *pte;
	292	int retval = 0;
	293
	294	pgd = pgd_offset(mm, addr & PAGE_MASK);
	295	if (pgd) {
d1953c88 DG	296	pud = pud_offset(pgd, addr & PAGE_MASK);
	297	if (pud && pud_present(*pud)) {
	298	pmd = pmd_offset(pud, addr & PAGE_MASK);
	299	if (pmd_present(*pmd)) {
	300	pte = pte_offset_map(pmd, addr & PAGE_MASK);
	301	if (pte) {
	302	retval = 1;
	303	*ptep = pte;
	304	if (pmdp)
	305	*pmdp = pmd;
	306	/* XXX caller needs to do pte_unmap, yuck */
	307	}
	308	}
	309	}
14cf11af PM	310	}
	311	return(retval);
	312	}
	313
e611939f	314	static int __change_page_attr_noflush(struct page *page, pgprot_t prot)
88df6e90 BH	315	{
	316	pte_t *kpte;
	317	pmd_t *kpmd;
	318	unsigned long address;
	319
	320	BUG_ON(PageHighMem(page));
	321	address = (unsigned long)page_address(page);
	322
3084cdb7	323	if (v_block_mapped(address))
88df6e90 BH	324	return 0;
	325	if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
	326	return -EINVAL;
50891457	327	__set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
88df6e90 BH	328	pte_unmap(kpte);
	329
	330	return 0;
	331	}
	332
	333	/*
	334	* Change the page attributes of an page in the linear mapping.
	335	*
3184cc4b	336	* THIS DOES NOTHING WITH BAT MAPPINGS, DEBUG USE ONLY
88df6e90 BH	337	*/
	338	static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
	339	{
	340	int i, err = 0;
	341	unsigned long flags;
e611939f	342	struct page *start = page;
88df6e90 BH	343
	344	local_irq_save(flags);
	345	for (i = 0; i < numpages; i++, page++) {
e611939f	346	err = __change_page_attr_noflush(page, prot);
88df6e90 BH	347	if (err)
	348	break;
	349	}
e611939f	350	wmb();
7c6a4f3b	351	local_irq_restore(flags);
e611939f CL	352	flush_tlb_kernel_range((unsigned long)page_address(start),
e611939f CL	353	(unsigned long)page_address(page));
88df6e90 BH	354	return err;
	355	}
	356
3184cc4b CL	357	void mark_initmem_nx(void)
	358	{
	359	struct page *page = virt_to_page(_sinittext);
	360	unsigned long numpages = PFN_UP((unsigned long)_einittext) -
	361	PFN_DOWN((unsigned long)_sinittext);
	362
63b2bc61 CL	363	if (v_block_mapped((unsigned long)_stext) + 1)
	364	mmu_mark_initmem_nx();
	365	else
	366	change_page_attr(page, numpages, PAGE_KERNEL);
3184cc4b	367	}
88df6e90	368
95902e6c CL	369	#ifdef CONFIG_STRICT_KERNEL_RWX
	370	void mark_rodata_ro(void)
	371	{
	372	struct page *page;
	373	unsigned long numpages;
	374
63b2bc61 CL	375	if (v_block_mapped((unsigned long)_sinittext)) {
	376	mmu_mark_rodata_ro();
	377	return;
	378	}
	379
95902e6c CL	380	page = virt_to_page(_stext);
	381	numpages = PFN_UP((unsigned long)_etext) -
	382	PFN_DOWN((unsigned long)_stext);
	383
	384	change_page_attr(page, numpages, PAGE_KERNEL_ROX);
	385	/*
	386	* mark .rodata as read only. Use __init_begin rather than __end_rodata
	387	* to cover NOTES and EXCEPTION_TABLE.
	388	*/
	389	page = virt_to_page(__start_rodata);
	390	numpages = PFN_UP((unsigned long)__init_begin) -
	391	PFN_DOWN((unsigned long)__start_rodata);
	392
	393	change_page_attr(page, numpages, PAGE_KERNEL_RO);
453d87f6 RC	394
	395	// mark_initmem_nx() should have already run by now
	396	ptdump_check_wx();
95902e6c CL	397	}
	398	#endif
	399
3184cc4b	400	#ifdef CONFIG_DEBUG_PAGEALLOC
031bc574	401	void __kernel_map_pages(struct page *page, int numpages, int enable)
88df6e90 BH	402	{
	403	if (PageHighMem(page))
	404	return;
	405
	406	change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
	407	}
	408	#endif /* CONFIG_DEBUG_PAGEALLOC */