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// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 1995-2005 Russell King
// Copyright (C) 2012 ARM Ltd.
// Copyright (C) 2013-2017 Andes Technology Corporation
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
#include <linux/highmem.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/tlb.h>
#include <asm/page.h>
DEFINE_SPINLOCK(anon_alias_lock);
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
/*
* empty_zero_page is a special page that is used for
* zero-initialized data and COW.
*/
struct page *empty_zero_page;
EXPORT_SYMBOL(empty_zero_page);
static void __init zone_sizes_init(void)
{
unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
max_zone_pfn[ZONE_HIGHMEM] = max_pfn;
#endif
free_area_init(max_zone_pfn);
}
/*
* Map all physical memory under high_memory into kernel's address space.
*
* This is explicitly coded for two-level page tables, so if you need
* something else then this needs to change.
*/
static void __init map_ram(void)
{
unsigned long v, p, e;
pgd_t *pge;
p4d_t *p4e;
pud_t *pue;
pmd_t *pme;
pte_t *pte;
/* These mark extents of read-only kernel pages...
* ...from vmlinux.lds.S
*/
p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
v = (u32) __va(p);
pge = pgd_offset_k(v);
while (p < e) {
int j;
p4e = p4d_offset(pge, v);
pue = pud_offset(p4e, v);
pme = pmd_offset(pue, v);
if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
panic("%s: Kernel hardcoded for "
"two-level page tables", __func__);
}
/* Alloc one page for holding PTE's... */
pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
if (!pte)
panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
/* Fill the newly allocated page with PTE'S */
for (j = 0; p < e && j < PTRS_PER_PTE;
v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
/* Create mapping between p and v. */
/* TODO: more fine grant for page access permission */
set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL)));
}
pge++;
}
}
static pmd_t *fixmap_pmd_p;
static void __init fixedrange_init(void)
{
unsigned long vaddr;
pmd_t *pmd;
#ifdef CONFIG_HIGHMEM
pte_t *pte;
#endif /* CONFIG_HIGHMEM */
/*
* Fixed mappings:
*/
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
pmd = pmd_off_k(vaddr);
fixmap_pmd_p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
if (!fixmap_pmd_p)
panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
#ifdef CONFIG_HIGHMEM
/*
* Permanent kmaps:
*/
vaddr = PKMAP_BASE;
pmd = pmd_off_k(vaddr);
pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
if (!pte)
panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
pkmap_page_table = pte;
#endif /* CONFIG_HIGHMEM */
}
/*
* paging_init() sets up the page tables, initialises the zone memory
* maps, and sets up the zero page, bad page and bad page tables.
*/
void __init paging_init(void)
{
int i;
void *zero_page;
pr_info("Setting up paging and PTEs.\n");
/* clear out the init_mm.pgd that will contain the kernel's mappings */
for (i = 0; i < PTRS_PER_PGD; i++)
swapper_pg_dir[i] = __pgd(1);
map_ram();
fixedrange_init();
/* allocate space for empty_zero_page */
zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
if (!zero_page)
panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
zone_sizes_init();
empty_zero_page = virt_to_page(zero_page);
flush_dcache_page(empty_zero_page);
}
static inline void __init free_highmem(void)
{
#ifdef CONFIG_HIGHMEM
unsigned long pfn;
for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
if (!memblock_is_reserved(paddr))
free_highmem_page(pfn_to_page(pfn));
}
#endif
}
static void __init set_max_mapnr_init(void)
{
max_mapnr = max_pfn;
}
/*
* mem_init() marks the free areas in the mem_map and tells us how much
* memory is free. This is done after various parts of the system have
* claimed their memory after the kernel image.
*/
void __init mem_init(void)
{
phys_addr_t memory_start = memblock_start_of_DRAM();
BUG_ON(!mem_map);
set_max_mapnr_init();
free_highmem();
/* this will put all low memory onto the freelists */
memblock_free_all();
pr_info("virtual kernel memory layout:\n"
" fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#ifdef CONFIG_HIGHMEM
" pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#endif
" consist : 0x%08lx - 0x%08lx (%4ld MB)\n"
" vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
" lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
" .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
" .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
" .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
#ifdef CONFIG_HIGHMEM
PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
(LAST_PKMAP * PAGE_SIZE) >> 10,
#endif
CONSISTENT_BASE, CONSISTENT_END,
((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
(unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
(unsigned long)__va(memory_start), (unsigned long)high_memory,
((unsigned long)high_memory -
(unsigned long)__va(memory_start)) >> 20,
(unsigned long)&__init_begin, (unsigned long)&__init_end,
((unsigned long)&__init_end -
(unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
(unsigned long)&_edata,
((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
(unsigned long)&_text, (unsigned long)&_etext,
((unsigned long)&_etext - (unsigned long)&_text) >> 10);
/*
* Check boundaries twice: Some fundamental inconsistencies can
* be detected at build time already.
*/
#ifdef CONFIG_HIGHMEM
BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
#endif
BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
#ifdef CONFIG_HIGHMEM
BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
BUG_ON(CONSISTENT_END > PKMAP_BASE);
#endif
BUG_ON(VMALLOC_END > CONSISTENT_BASE);
BUG_ON(VMALLOC_START >= VMALLOC_END);
BUG_ON((unsigned long)high_memory > VMALLOC_START);
return;
}
void __set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags)
{
unsigned long addr = __fix_to_virt(idx);
pte_t *pte;
BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];
if (pgprot_val(flags)) {
set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
} else {
pte_clear(&init_mm, addr, pte);
flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
}
}
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