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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#include <linux/stddef.h>
#include <linux/module.h>
#include <linux/memblock.h>
#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <asm/fixmap.h>
#include <asm/page.h>
#include <as-layout.h>
#include <init.h>
#include <kern.h>
#include <kern_util.h>
#include <mem_user.h>
#include <os.h>
/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
unsigned long *empty_zero_page = NULL;
EXPORT_SYMBOL(empty_zero_page);
/*
* Initialized during boot, and readonly for initializing page tables
* afterwards
*/
pgd_t swapper_pg_dir[PTRS_PER_PGD];
/* Initialized at boot time, and readonly after that */
unsigned long long highmem;
EXPORT_SYMBOL(highmem);
int kmalloc_ok = 0;
/* Used during early boot */
static unsigned long brk_end;
void __init mem_init(void)
{
/* clear the zero-page */
memset(empty_zero_page, 0, PAGE_SIZE);
/* Map in the area just after the brk now that kmalloc is about
* to be turned on.
*/
brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
memblock_free((void *)brk_end, uml_reserved - brk_end);
uml_reserved = brk_end;
/* this will put all low memory onto the freelists */
memblock_free_all();
max_low_pfn = totalram_pages();
max_pfn = max_low_pfn;
kmalloc_ok = 1;
}
/*
* Create a page table and place a pointer to it in a middle page
* directory entry.
*/
static void __init one_page_table_init(pmd_t *pmd)
{
if (pmd_none(*pmd)) {
pte_t *pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
PAGE_SIZE);
if (!pte)
panic("%s: Failed to allocate %lu bytes align=%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
set_pmd(pmd, __pmd(_KERNPG_TABLE +
(unsigned long) __pa(pte)));
BUG_ON(pte != pte_offset_kernel(pmd, 0));
}
}
static void __init one_md_table_init(pud_t *pud)
{
#ifdef CONFIG_3_LEVEL_PGTABLES
pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
if (!pmd_table)
panic("%s: Failed to allocate %lu bytes align=%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
if (pmd_table != pmd_offset(pud, 0))
BUG();
#endif
}
static void __init fixrange_init(unsigned long start, unsigned long end,
pgd_t *pgd_base)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
int i, j;
unsigned long vaddr;
vaddr = start;
i = pgd_index(vaddr);
j = pmd_index(vaddr);
pgd = pgd_base + i;
for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
p4d = p4d_offset(pgd, vaddr);
pud = pud_offset(p4d, vaddr);
if (pud_none(*pud))
one_md_table_init(pud);
pmd = pmd_offset(pud, vaddr);
for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
one_page_table_init(pmd);
vaddr += PMD_SIZE;
}
j = 0;
}
}
static void __init fixaddr_user_init( void)
{
#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
long size = FIXADDR_USER_END - FIXADDR_USER_START;
pte_t *pte;
phys_t p;
unsigned long v, vaddr = FIXADDR_USER_START;
if (!size)
return;
fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE);
if (!v)
panic("%s: Failed to allocate %lu bytes align=%lx\n",
__func__, size, PAGE_SIZE);
memcpy((void *) v , (void *) FIXADDR_USER_START, size);
p = __pa(v);
for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
p += PAGE_SIZE) {
pte = virt_to_kpte(vaddr);
pte_set_val(*pte, p, PAGE_READONLY);
}
#endif
}
void __init paging_init(void)
{
unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
unsigned long vaddr;
empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
PAGE_SIZE);
if (!empty_zero_page)
panic("%s: Failed to allocate %lu bytes align=%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
max_zone_pfn[ZONE_NORMAL] = end_iomem >> PAGE_SHIFT;
free_area_init(max_zone_pfn);
/*
* Fixed mappings, only the page table structure has to be
* created - mappings will be set by set_fixmap():
*/
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
fixaddr_user_init();
}
/*
* This can't do anything because nothing in the kernel image can be freed
* since it's not in kernel physical memory.
*/
void free_initmem(void)
{
}
/* Allocate and free page tables. */
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
if (pgd) {
memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
memcpy(pgd + USER_PTRS_PER_PGD,
swapper_pg_dir + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
}
return pgd;
}
void *uml_kmalloc(int size, int flags)
{
return kmalloc(size, flags);
}
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