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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/arch/ppc/mm/init.c

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C
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/*
* PowerPC version
* 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
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
* PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
*
* 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/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/btext.h>
#include <asm/tlb.h>
#include <asm/bootinfo.h>
#include "mem_pieces.h"
#include "mmu_decl.h"
#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
/* The amount of lowmem must be within 0xF0000000 - KERNELBASE. */
#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE))
#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
#endif
#endif
#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
unsigned long total_memory;
unsigned long total_lowmem;
unsigned long ppc_memstart;
unsigned long ppc_memoffset = PAGE_OFFSET;
int mem_init_done;
int init_bootmem_done;
int boot_mapsize;
extern char _end[];
extern char etext[], _stext[];
extern char __init_begin, __init_end;
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
pgprot_t kmap_prot;
EXPORT_SYMBOL(kmap_prot);
EXPORT_SYMBOL(kmap_pte);
#endif
void MMU_init(void);
void set_phys_avail(unsigned long total_ram);
/* XXX should be in current.h -- paulus */
extern struct task_struct *current_set[NR_CPUS];
char *klimit = _end;
struct mem_pieces phys_avail;
/*
* this tells the system to map all of ram with the segregs
* (i.e. page tables) instead of the bats.
* -- Cort
*/
int __map_without_bats;
int __map_without_ltlbs;
/* max amount of RAM to use */
unsigned long __max_memory;
/* max amount of low RAM to map in */
unsigned long __max_low_memory = MAX_LOW_MEM;
void show_mem(void)
{
int i,free = 0,total = 0,reserved = 0;
int shared = 0, cached = 0;
int highmem = 0;
printk("Mem-info:\n");
show_free_areas();
i = max_mapnr;
while (i-- > 0) {
total++;
if (PageHighMem(mem_map+i))
highmem++;
if (PageReserved(mem_map+i))
reserved++;
else if (PageSwapCache(mem_map+i))
cached++;
else if (!page_count(mem_map+i))
free++;
else
shared += page_count(mem_map+i) - 1;
}
printk("%d pages of RAM\n",total);
printk("%d pages of HIGHMEM\n", highmem);
printk("%d free pages\n",free);
printk("%d reserved pages\n",reserved);
printk("%d pages shared\n",shared);
printk("%d pages swap cached\n",cached);
}
/* Free up now-unused memory */
static void free_sec(unsigned long start, unsigned long end, const char *name)
{
unsigned long cnt = 0;
while (start < end) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page(start);
cnt++;
start += PAGE_SIZE;
}
if (cnt) {
printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
totalram_pages += cnt;
}
}
void free_initmem(void)
{
#define FREESEC(TYPE) \
free_sec((unsigned long)(&__ ## TYPE ## _begin), \
(unsigned long)(&__ ## TYPE ## _end), \
#TYPE);
printk ("Freeing unused kernel memory:");
FREESEC(init);
printk("\n");
ppc_md.progress = NULL;
#undef FREESEC
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page(start);
totalram_pages++;
}
}
#endif
/*
* Check for command-line options that affect what MMU_init will do.
*/
void MMU_setup(void)
{
/* Check for nobats option (used in mapin_ram). */
if (strstr(cmd_line, "nobats")) {
__map_without_bats = 1;
}
if (strstr(cmd_line, "noltlbs")) {
__map_without_ltlbs = 1;
}
/* Look for mem= option on command line */
if (strstr(cmd_line, "mem=")) {
char *p, *q;
unsigned long maxmem = 0;
for (q = cmd_line; (p = strstr(q, "mem=")) != 0; ) {
q = p + 4;
if (p > cmd_line && p[-1] != ' ')
continue;
maxmem = simple_strtoul(q, &q, 0);
if (*q == 'k' || *q == 'K') {
maxmem <<= 10;
++q;
} else if (*q == 'm' || *q == 'M') {
maxmem <<= 20;
++q;
}
}
__max_memory = maxmem;
}
}
/*
* MMU_init sets up the basic memory mappings for the kernel,
* including both RAM and possibly some I/O regions,
* and sets up the page tables and the MMU hardware ready to go.
*/
void __init MMU_init(void)
{
if (ppc_md.progress)
ppc_md.progress("MMU:enter", 0x111);
/* parse args from command line */
MMU_setup();
/*
* Figure out how much memory we have, how much
* is lowmem, and how much is highmem. If we were
* passed the total memory size from the bootloader,
* just use it.
*/
if (boot_mem_size)
total_memory = boot_mem_size;
else
total_memory = ppc_md.find_end_of_memory();
if (__max_memory && total_memory > __max_memory)
total_memory = __max_memory;
total_lowmem = total_memory;
if (total_lowmem > __max_low_memory) {
total_lowmem = __max_low_memory;
#ifndef CONFIG_HIGHMEM
total_memory = total_lowmem;
#endif /* CONFIG_HIGHMEM */
}
set_phys_avail(total_lowmem);
/* Initialize the MMU hardware */
if (ppc_md.progress)
ppc_md.progress("MMU:hw init", 0x300);
MMU_init_hw();
/* Map in all of RAM starting at KERNELBASE */
if (ppc_md.progress)
ppc_md.progress("MMU:mapin", 0x301);
mapin_ram();
#ifdef CONFIG_HIGHMEM
ioremap_base = PKMAP_BASE;
#else
ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
#endif /* CONFIG_HIGHMEM */
ioremap_bot = ioremap_base;
/* Map in I/O resources */
if (ppc_md.progress)
ppc_md.progress("MMU:setio", 0x302);
if (ppc_md.setup_io_mappings)
ppc_md.setup_io_mappings();
/* Initialize the context management stuff */
mmu_context_init();
if (ppc_md.progress)
ppc_md.progress("MMU:exit", 0x211);
#ifdef CONFIG_BOOTX_TEXT
/* By default, we are no longer mapped */
boot_text_mapped = 0;
/* Must be done last, or ppc_md.progress will die. */
map_boot_text();
#endif
}
/* This is only called until mem_init is done. */
void __init *early_get_page(void)
{
void *p;
if (init_bootmem_done) {
p = alloc_bootmem_pages(PAGE_SIZE);
} else {
p = mem_pieces_find(PAGE_SIZE, PAGE_SIZE);
}
return p;
}
/*
* Initialize the bootmem system and give it all the memory we
* have available.
*/
void __init do_init_bootmem(void)
{
unsigned long start, size;
int i;
/*
* Find an area to use for the bootmem bitmap.
* We look for the first area which is at least
* 128kB in length (128kB is enough for a bitmap
* for 4GB of memory, using 4kB pages), plus 1 page
* (in case the address isn't page-aligned).
*/
start = 0;
size = 0;
for (i = 0; i < phys_avail.n_regions; ++i) {
unsigned long a = phys_avail.regions[i].address;
unsigned long s = phys_avail.regions[i].size;
if (s <= size)
continue;
start = a;
size = s;
if (s >= 33 * PAGE_SIZE)
break;
}
start = PAGE_ALIGN(start);
min_low_pfn = start >> PAGE_SHIFT;
max_low_pfn = (PPC_MEMSTART + total_lowmem) >> PAGE_SHIFT;
max_pfn = (PPC_MEMSTART + total_memory) >> PAGE_SHIFT;
boot_mapsize = init_bootmem_node(&contig_page_data, min_low_pfn,
PPC_MEMSTART >> PAGE_SHIFT,
max_low_pfn);
/* remove the bootmem bitmap from the available memory */
mem_pieces_remove(&phys_avail, start, boot_mapsize, 1);
/* add everything in phys_avail into the bootmem map */
for (i = 0; i < phys_avail.n_regions; ++i)
free_bootmem(phys_avail.regions[i].address,
phys_avail.regions[i].size);
init_bootmem_done = 1;
}
/*
* paging_init() sets up the page tables - in fact we've already done this.
*/
void __init paging_init(void)
{
unsigned long start_pfn, end_pfn;
unsigned long max_zone_pfns[MAX_NR_ZONES];
#ifdef CONFIG_HIGHMEM
map_page(PKMAP_BASE, 0, 0); /* XXX gross */
pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
(PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
(KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
kmap_prot = PAGE_KERNEL;
#endif /* CONFIG_HIGHMEM */
/* All pages are DMA-able so we put them all in the DMA zone. */
start_pfn = __pa(PAGE_OFFSET) >> PAGE_SHIFT;
end_pfn = start_pfn + (total_memory >> PAGE_SHIFT);
add_active_range(0, start_pfn, end_pfn);
memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
#ifdef CONFIG_HIGHMEM
max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
max_zone_pfns[ZONE_HIGHMEM] = total_memory >> PAGE_SHIFT;
#else
max_zone_pfns[ZONE_DMA] = total_memory >> PAGE_SHIFT;
#endif /* CONFIG_HIGHMEM */
free_area_init_nodes(max_zone_pfns);
}
void __init mem_init(void)
{
unsigned long addr;
int codepages = 0;
int datapages = 0;
int initpages = 0;
#ifdef CONFIG_HIGHMEM
unsigned long highmem_mapnr;
highmem_mapnr = total_lowmem >> PAGE_SHIFT;
#endif /* CONFIG_HIGHMEM */
max_mapnr = total_memory >> PAGE_SHIFT;
high_memory = (void *) __va(PPC_MEMSTART + total_lowmem);
num_physpages = max_mapnr; /* RAM is assumed contiguous */
totalram_pages += free_all_bootmem();
#ifdef CONFIG_BLK_DEV_INITRD
/* if we are booted from BootX with an initial ramdisk,
make sure the ramdisk pages aren't reserved. */
if (initrd_start) {
for (addr = initrd_start; addr < initrd_end; addr += PAGE_SIZE)
ClearPageReserved(virt_to_page(addr));
}
#endif /* CONFIG_BLK_DEV_INITRD */
for (addr = PAGE_OFFSET; addr < (unsigned long)high_memory;
addr += PAGE_SIZE) {
if (!PageReserved(virt_to_page(addr)))
continue;
if (addr < (ulong) etext)
codepages++;
else if (addr >= (unsigned long)&__init_begin
&& addr < (unsigned long)&__init_end)
initpages++;
else if (addr < (ulong) klimit)
datapages++;
}
#ifdef CONFIG_HIGHMEM
{
unsigned long pfn;
for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
struct page *page = mem_map + pfn;
ClearPageReserved(page);
init_page_count(page);
__free_page(page);
totalhigh_pages++;
}
totalram_pages += totalhigh_pages;
}
#endif /* CONFIG_HIGHMEM */
printk("Memory: %luk available (%dk kernel code, %dk data, %dk init, %ldk highmem)\n",
(unsigned long)nr_free_pages()<< (PAGE_SHIFT-10),
codepages<< (PAGE_SHIFT-10), datapages<< (PAGE_SHIFT-10),
initpages<< (PAGE_SHIFT-10),
(unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
mem_init_done = 1;
}
/*
* Set phys_avail to the amount of physical memory,
* less the kernel text/data/bss.
*/
void __init
set_phys_avail(unsigned long total_memory)
{
unsigned long kstart, ksize;
/*
* Initially, available physical memory is equivalent to all
* physical memory.
*/
phys_avail.regions[0].address = PPC_MEMSTART;
phys_avail.regions[0].size = total_memory;
phys_avail.n_regions = 1;
/*
* Map out the kernel text/data/bss from the available physical
* memory.
*/
kstart = __pa(_stext); /* should be 0 */
ksize = PAGE_ALIGN(klimit - _stext);
mem_pieces_remove(&phys_avail, kstart, ksize, 0);
mem_pieces_remove(&phys_avail, 0, 0x4000, 0);
#if defined(CONFIG_BLK_DEV_INITRD)
/* Remove the init RAM disk from the available memory. */
if (initrd_start) {
mem_pieces_remove(&phys_avail, __pa(initrd_start),
initrd_end - initrd_start, 1);
}
#endif /* CONFIG_BLK_DEV_INITRD */
}
/* Mark some memory as reserved by removing it from phys_avail. */
void __init reserve_phys_mem(unsigned long start, unsigned long size)
{
mem_pieces_remove(&phys_avail, start, size, 1);
}
/*
* This is called when a page has been modified by the kernel.
* It just marks the page as not i-cache clean. We do the i-cache
* flush later when the page is given to a user process, if necessary.
*/
void flush_dcache_page(struct page *page)
{
clear_bit(PG_arch_1, &page->flags);
}
void flush_dcache_icache_page(struct page *page)
{
#ifdef CONFIG_BOOKE
void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
__flush_dcache_icache(start);
kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
#elif defined(CONFIG_8xx)
/* On 8xx there is no need to kmap since highmem is not supported */
__flush_dcache_icache(page_address(page));
#else
__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
#endif
}
void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
clear_page(page);
clear_bit(PG_arch_1, &pg->flags);
}
void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *pg)
{
copy_page(vto, vfrom);
clear_bit(PG_arch_1, &pg->flags);
}
void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
unsigned long addr, int len)
{
unsigned long maddr;
maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
flush_icache_range(maddr, maddr + len);
kunmap(page);
}
/*
* This is called at the end of handling a user page fault, when the
* fault has been handled by updating a PTE in the linux page tables.
* We use it to preload an HPTE into the hash table corresponding to
* the updated linux PTE.
*/
void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
pte_t pte)
{
/* handle i-cache coherency */
unsigned long pfn = pte_pfn(pte);
if (pfn_valid(pfn)) {
struct page *page = pfn_to_page(pfn);
#ifdef CONFIG_8xx
/* On 8xx, the TLB handlers work in 2 stages:
* First, a zeroed entry is loaded by TLBMiss handler,
* which causes the TLBError handler to be triggered.
* That means the zeroed TLB has to be invalidated
* whenever a page miss occurs.
*/
_tlbie(address, 0 /* 8xx doesn't care about PID */);
#endif
if (!PageReserved(page)
&& !test_bit(PG_arch_1, &page->flags)) {
if (vma->vm_mm == current->active_mm)
__flush_dcache_icache((void *) address);
else
flush_dcache_icache_page(page);
set_bit(PG_arch_1, &page->flags);
}
}
#ifdef CONFIG_PPC_STD_MMU
/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
if (Hash != 0 && pte_young(pte)) {
struct mm_struct *mm;
pmd_t *pmd;
mm = (address < TASK_SIZE)? vma->vm_mm: &init_mm;
pmd = pmd_offset(pgd_offset(mm, address), address);
if (!pmd_none(*pmd))
add_hash_page(mm->context.id, address, pmd_val(*pmd));
}
#endif
}
/*
* This is called by /dev/mem to know if a given address has to
* be mapped non-cacheable or not
*/
int page_is_ram(unsigned long pfn)
{
return pfn < max_pfn;
}
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
if (ppc_md.phys_mem_access_prot)
return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
if (!page_is_ram(pfn))
vma_prot = __pgprot(pgprot_val(vma_prot)
| _PAGE_GUARDED | _PAGE_NO_CACHE);
return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);
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