Contributors: 63
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Linus Torvalds (pre-git) |
566 |
19.51% |
46 |
21.80% |
| Yinghai Lu |
487 |
16.79% |
21 |
9.95% |
| Jan Beulich |
278 |
9.58% |
4 |
1.90% |
| Ingo Molnar |
252 |
8.69% |
11 |
5.21% |
| Jeremy Fitzhardinge |
164 |
5.65% |
9 |
4.27% |
| Dan Aloni |
137 |
4.72% |
1 |
0.47% |
| Tejun Heo |
135 |
4.65% |
6 |
2.84% |
| Andrew Morton |
121 |
4.17% |
13 |
6.16% |
| Ian Campbell |
93 |
3.21% |
1 |
0.47% |
| Andi Kleen |
88 |
3.03% |
4 |
1.90% |
| Suresh B. Siddha |
80 |
2.76% |
2 |
0.95% |
| Pekka J Enberg |
52 |
1.79% |
7 |
3.32% |
| Matthieu CASTET |
51 |
1.76% |
1 |
0.47% |
| Brian Gerst |
50 |
1.72% |
4 |
1.90% |
| Dave Hansen |
43 |
1.48% |
7 |
3.32% |
| Arjan van de Ven |
27 |
0.93% |
3 |
1.42% |
| Kirill A. Shutemov |
26 |
0.90% |
1 |
0.47% |
| Andrew Lutomirski |
23 |
0.79% |
1 |
0.47% |
| Thomas Gleixner |
21 |
0.72% |
4 |
1.90% |
| Borislav Petkov |
18 |
0.62% |
3 |
1.42% |
| Linus Torvalds |
16 |
0.55% |
8 |
3.79% |
| Rafael J. Wysocki |
12 |
0.41% |
1 |
0.47% |
| Paolo Bonzini |
12 |
0.41% |
1 |
0.47% |
| Attilio Rao |
10 |
0.34% |
3 |
1.42% |
| Andy Whitcroft |
10 |
0.34% |
2 |
0.95% |
| Jiang Liu |
9 |
0.31% |
2 |
0.95% |
| Mike Rapoport |
8 |
0.28% |
3 |
1.42% |
| Steven Rostedt |
7 |
0.24% |
1 |
0.47% |
| Pavel Tatashin |
7 |
0.24% |
1 |
0.47% |
| Ingo Brueckl |
6 |
0.21% |
1 |
0.47% |
| Andres Salomon |
6 |
0.21% |
2 |
0.95% |
| Tang Chen |
5 |
0.17% |
1 |
0.47% |
| Richard Henderson |
5 |
0.17% |
1 |
0.47% |
| Adrian Bunk |
5 |
0.17% |
2 |
0.95% |
| Kefeng Wang |
5 |
0.17% |
1 |
0.47% |
| Krzysztof Mazur |
5 |
0.17% |
1 |
0.47% |
| Jaswinder Singh Rajput |
4 |
0.14% |
1 |
0.47% |
| Joerg Roedel |
4 |
0.14% |
1 |
0.47% |
| Nadia Yvette Chambers |
4 |
0.14% |
2 |
0.95% |
| H. Peter Anvin |
4 |
0.14% |
2 |
0.95% |
| Glauber de Oliveira Costa |
4 |
0.14% |
1 |
0.47% |
| Stanislaw Gruszka |
3 |
0.10% |
1 |
0.47% |
| Huang Ying |
3 |
0.10% |
2 |
0.95% |
| Randy Dunlap |
3 |
0.10% |
1 |
0.47% |
| Zhao Lei |
3 |
0.10% |
1 |
0.47% |
| Peter Zijlstra |
3 |
0.10% |
1 |
0.47% |
| Eric Sesterhenn / Snakebyte |
3 |
0.10% |
1 |
0.47% |
| Logan Gunthorpe |
3 |
0.10% |
1 |
0.47% |
| Harvey Harrison |
2 |
0.07% |
1 |
0.47% |
| Roman Zippel |
2 |
0.07% |
1 |
0.47% |
| Tony Luck |
2 |
0.07% |
1 |
0.47% |
| Christoph Hellwig |
2 |
0.07% |
2 |
0.95% |
| Shaohua Li |
2 |
0.07% |
1 |
0.47% |
| Juergen Gross |
1 |
0.03% |
1 |
0.47% |
| Mathias Krause |
1 |
0.03% |
1 |
0.47% |
| Américo Wang |
1 |
0.03% |
1 |
0.47% |
| Ravikiran G. Thirumalai |
1 |
0.03% |
1 |
0.47% |
| Dmitri Vorobiev |
1 |
0.03% |
1 |
0.47% |
| Hugh Dickins |
1 |
0.03% |
1 |
0.47% |
| Lucas De Marchi |
1 |
0.03% |
1 |
0.47% |
| Stefan Agner |
1 |
0.03% |
1 |
0.47% |
| Laura Abbott |
1 |
0.03% |
1 |
0.47% |
| Peter Xu |
1 |
0.03% |
1 |
0.47% |
| Total |
2901 |
|
211 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright (C) 1995 Linus Torvalds
*
* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/pci.h>
#include <linux/pfn.h>
#include <linux/poison.h>
#include <linux/memblock.h>
#include <linux/proc_fs.h>
#include <linux/memory_hotplug.h>
#include <linux/initrd.h>
#include <linux/cpumask.h>
#include <linux/gfp.h>
#include <asm/asm.h>
#include <asm/bios_ebda.h>
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/dma.h>
#include <asm/fixmap.h>
#include <asm/e820/api.h>
#include <asm/apic.h>
#include <asm/bugs.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/olpc_ofw.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/set_memory.h>
#include <asm/page_types.h>
#include <asm/cpu_entry_area.h>
#include <asm/init.h>
#include <asm/pgtable_areas.h>
#include <asm/numa.h>
#include "mm_internal.h"
unsigned long highstart_pfn, highend_pfn;
bool __read_mostly __vmalloc_start_set = false;
/*
* Creates a middle page table and puts a pointer to it in the
* given global directory entry. This only returns the gd entry
* in non-PAE compilation mode, since the middle layer is folded.
*/
static pmd_t * __init one_md_table_init(pgd_t *pgd)
{
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd_table;
#ifdef CONFIG_X86_PAE
if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
pmd_table = (pmd_t *)alloc_low_page();
set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
p4d = p4d_offset(pgd, 0);
pud = pud_offset(p4d, 0);
BUG_ON(pmd_table != pmd_offset(pud, 0));
return pmd_table;
}
#endif
p4d = p4d_offset(pgd, 0);
pud = pud_offset(p4d, 0);
pmd_table = pmd_offset(pud, 0);
return pmd_table;
}
/*
* Create a page table and place a pointer to it in a middle page
* directory entry:
*/
static pte_t * __init one_page_table_init(pmd_t *pmd)
{
if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
pte_t *page_table = (pte_t *)alloc_low_page();
set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
BUG_ON(page_table != pte_offset_kernel(pmd, 0));
}
return pte_offset_kernel(pmd, 0);
}
pmd_t * __init populate_extra_pmd(unsigned long vaddr)
{
int pgd_idx = pgd_index(vaddr);
int pmd_idx = pmd_index(vaddr);
return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx;
}
pte_t * __init populate_extra_pte(unsigned long vaddr)
{
int pte_idx = pte_index(vaddr);
pmd_t *pmd;
pmd = populate_extra_pmd(vaddr);
return one_page_table_init(pmd) + pte_idx;
}
static unsigned long __init
page_table_range_init_count(unsigned long start, unsigned long end)
{
unsigned long count = 0;
#ifdef CONFIG_HIGHMEM
int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
int pgd_idx, pmd_idx;
unsigned long vaddr;
if (pmd_idx_kmap_begin == pmd_idx_kmap_end)
return 0;
vaddr = start;
pgd_idx = pgd_index(vaddr);
pmd_idx = pmd_index(vaddr);
for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) {
for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
pmd_idx++) {
if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin &&
(vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end)
count++;
vaddr += PMD_SIZE;
}
pmd_idx = 0;
}
#endif
return count;
}
static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
unsigned long vaddr, pte_t *lastpte,
void **adr)
{
#ifdef CONFIG_HIGHMEM
/*
* Something (early fixmap) may already have put a pte
* page here, which causes the page table allocation
* to become nonlinear. Attempt to fix it, and if it
* is still nonlinear then we have to bug.
*/
int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
if (pmd_idx_kmap_begin != pmd_idx_kmap_end
&& (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
&& (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) {
pte_t *newpte;
int i;
BUG_ON(after_bootmem);
newpte = *adr;
for (i = 0; i < PTRS_PER_PTE; i++)
set_pte(newpte + i, pte[i]);
*adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE);
set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
BUG_ON(newpte != pte_offset_kernel(pmd, 0));
__flush_tlb_all();
pte = newpte;
}
BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
&& vaddr > fix_to_virt(FIX_KMAP_END)
&& lastpte && lastpte + PTRS_PER_PTE != pte);
#endif
return pte;
}
/*
* This function initializes a certain range of kernel virtual memory
* with new bootmem page tables, everywhere page tables are missing in
* the given range.
*
* NOTE: The pagetables are allocated contiguous on the physical space
* so we can cache the place of the first one and move around without
* checking the pgd every time.
*/
static void __init
page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
{
int pgd_idx, pmd_idx;
unsigned long vaddr;
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte = NULL;
unsigned long count = page_table_range_init_count(start, end);
void *adr = NULL;
if (count)
adr = alloc_low_pages(count);
vaddr = start;
pgd_idx = pgd_index(vaddr);
pmd_idx = pmd_index(vaddr);
pgd = pgd_base + pgd_idx;
for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
pmd = one_md_table_init(pgd);
pmd = pmd + pmd_index(vaddr);
for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
pmd++, pmd_idx++) {
pte = page_table_kmap_check(one_page_table_init(pmd),
pmd, vaddr, pte, &adr);
vaddr += PMD_SIZE;
}
pmd_idx = 0;
}
}
static inline int is_x86_32_kernel_text(unsigned long addr)
{
if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end)
return 1;
return 0;
}
/*
* This maps the physical memory to kernel virtual address space, a total
* of max_low_pfn pages, by creating page tables starting from address
* PAGE_OFFSET:
*/
unsigned long __init
kernel_physical_mapping_init(unsigned long start,
unsigned long end,
unsigned long page_size_mask,
pgprot_t prot)
{
int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
unsigned long last_map_addr = end;
unsigned long start_pfn, end_pfn;
pgd_t *pgd_base = swapper_pg_dir;
int pgd_idx, pmd_idx, pte_ofs;
unsigned long pfn;
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
unsigned pages_2m, pages_4k;
int mapping_iter;
start_pfn = start >> PAGE_SHIFT;
end_pfn = end >> PAGE_SHIFT;
/*
* First iteration will setup identity mapping using large/small pages
* based on use_pse, with other attributes same as set by
* the early code in head_32.S
*
* Second iteration will setup the appropriate attributes (NX, GLOBAL..)
* as desired for the kernel identity mapping.
*
* This two pass mechanism conforms to the TLB app note which says:
*
* "Software should not write to a paging-structure entry in a way
* that would change, for any linear address, both the page size
* and either the page frame or attributes."
*/
mapping_iter = 1;
if (!boot_cpu_has(X86_FEATURE_PSE))
use_pse = 0;
repeat:
pages_2m = pages_4k = 0;
pfn = start_pfn;
pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
pgd = pgd_base + pgd_idx;
for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
pmd = one_md_table_init(pgd);
if (pfn >= end_pfn)
continue;
#ifdef CONFIG_X86_PAE
pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
pmd += pmd_idx;
#else
pmd_idx = 0;
#endif
for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn;
pmd++, pmd_idx++) {
unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET;
/*
* Map with big pages if possible, otherwise
* create normal page tables:
*/
if (use_pse) {
unsigned int addr2;
pgprot_t prot = PAGE_KERNEL_LARGE;
/*
* first pass will use the same initial
* identity mapping attribute + _PAGE_PSE.
*/
pgprot_t init_prot =
__pgprot(PTE_IDENT_ATTR |
_PAGE_PSE);
pfn &= PMD_MASK >> PAGE_SHIFT;
addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
PAGE_OFFSET + PAGE_SIZE-1;
if (is_x86_32_kernel_text(addr) ||
is_x86_32_kernel_text(addr2))
prot = PAGE_KERNEL_LARGE_EXEC;
pages_2m++;
if (mapping_iter == 1)
set_pmd(pmd, pfn_pmd(pfn, init_prot));
else
set_pmd(pmd, pfn_pmd(pfn, prot));
pfn += PTRS_PER_PTE;
continue;
}
pte = one_page_table_init(pmd);
pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET);
pte += pte_ofs;
for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn;
pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) {
pgprot_t prot = PAGE_KERNEL;
/*
* first pass will use the same initial
* identity mapping attribute.
*/
pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR);
if (is_x86_32_kernel_text(addr))
prot = PAGE_KERNEL_EXEC;
pages_4k++;
if (mapping_iter == 1) {
set_pte(pte, pfn_pte(pfn, init_prot));
last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
} else
set_pte(pte, pfn_pte(pfn, prot));
}
}
}
if (mapping_iter == 1) {
/*
* update direct mapping page count only in the first
* iteration.
*/
update_page_count(PG_LEVEL_2M, pages_2m);
update_page_count(PG_LEVEL_4K, pages_4k);
/*
* local global flush tlb, which will flush the previous
* mappings present in both small and large page TLB's.
*/
__flush_tlb_all();
/*
* Second iteration will set the actual desired PTE attributes.
*/
mapping_iter = 2;
goto repeat;
}
return last_map_addr;
}
#ifdef CONFIG_HIGHMEM
static void __init permanent_kmaps_init(pgd_t *pgd_base)
{
unsigned long vaddr = PKMAP_BASE;
page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
pkmap_page_table = virt_to_kpte(vaddr);
}
void __init add_highpages_with_active_regions(int nid,
unsigned long start_pfn, unsigned long end_pfn)
{
phys_addr_t start, end;
u64 i;
for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) {
unsigned long pfn = clamp_t(unsigned long, PFN_UP(start),
start_pfn, end_pfn);
unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end),
start_pfn, end_pfn);
for ( ; pfn < e_pfn; pfn++)
if (pfn_valid(pfn))
free_highmem_page(pfn_to_page(pfn));
}
}
#else
static inline void permanent_kmaps_init(pgd_t *pgd_base)
{
}
#endif /* CONFIG_HIGHMEM */
void __init sync_initial_page_table(void)
{
clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
swapper_pg_dir + KERNEL_PGD_BOUNDARY,
KERNEL_PGD_PTRS);
/*
* sync back low identity map too. It is used for example
* in the 32-bit EFI stub.
*/
clone_pgd_range(initial_page_table,
swapper_pg_dir + KERNEL_PGD_BOUNDARY,
min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
}
void __init native_pagetable_init(void)
{
unsigned long pfn, va;
pgd_t *pgd, *base = swapper_pg_dir;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
/*
* Remove any mappings which extend past the end of physical
* memory from the boot time page table.
* In virtual address space, we should have at least two pages
* from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
* definition. And max_low_pfn is set to VMALLOC_END physical
* address. If initial memory mapping is doing right job, we
* should have pte used near max_low_pfn or one pmd is not present.
*/
for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
pgd = base + pgd_index(va);
if (!pgd_present(*pgd))
break;
p4d = p4d_offset(pgd, va);
pud = pud_offset(p4d, va);
pmd = pmd_offset(pud, va);
if (!pmd_present(*pmd))
break;
/* should not be large page here */
if (pmd_leaf(*pmd)) {
pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n",
pfn, pmd, __pa(pmd));
BUG_ON(1);
}
pte = pte_offset_kernel(pmd, va);
if (!pte_present(*pte))
break;
printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
pfn, pmd, __pa(pmd), pte, __pa(pte));
pte_clear(NULL, va, pte);
}
paging_init();
}
/*
* Build a proper pagetable for the kernel mappings. Up until this
* point, we've been running on some set of pagetables constructed by
* the boot process.
*
* This will be a pagetable constructed in arch/x86/kernel/head_32.S.
* The root of the pagetable will be swapper_pg_dir.
*
* In general, pagetable_init() assumes that the pagetable may already
* be partially populated, and so it avoids stomping on any existing
* mappings.
*/
void __init early_ioremap_page_table_range_init(void)
{
pgd_t *pgd_base = swapper_pg_dir;
unsigned long vaddr, end;
/*
* 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;
end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
page_table_range_init(vaddr, end, pgd_base);
early_ioremap_reset();
}
static void __init pagetable_init(void)
{
pgd_t *pgd_base = swapper_pg_dir;
permanent_kmaps_init(pgd_base);
}
#define DEFAULT_PTE_MASK ~(_PAGE_NX | _PAGE_GLOBAL)
/* Bits supported by the hardware: */
pteval_t __supported_pte_mask __read_mostly = DEFAULT_PTE_MASK;
/* Bits allowed in normal kernel mappings: */
pteval_t __default_kernel_pte_mask __read_mostly = DEFAULT_PTE_MASK;
EXPORT_SYMBOL_GPL(__supported_pte_mask);
/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
EXPORT_SYMBOL(__default_kernel_pte_mask);
/* user-defined highmem size */
static unsigned int highmem_pages = -1;
/*
* highmem=size forces highmem to be exactly 'size' bytes.
* This works even on boxes that have no highmem otherwise.
* This also works to reduce highmem size on bigger boxes.
*/
static int __init parse_highmem(char *arg)
{
if (!arg)
return -EINVAL;
highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
return 0;
}
early_param("highmem", parse_highmem);
#define MSG_HIGHMEM_TOO_BIG \
"highmem size (%luMB) is bigger than pages available (%luMB)!\n"
#define MSG_LOWMEM_TOO_SMALL \
"highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
/*
* All of RAM fits into lowmem - but if user wants highmem
* artificially via the highmem=x boot parameter then create
* it:
*/
static void __init lowmem_pfn_init(void)
{
/* max_low_pfn is 0, we already have early_res support */
max_low_pfn = max_pfn;
if (highmem_pages == -1)
highmem_pages = 0;
#ifdef CONFIG_HIGHMEM
if (highmem_pages >= max_pfn) {
printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
pages_to_mb(highmem_pages), pages_to_mb(max_pfn));
highmem_pages = 0;
}
if (highmem_pages) {
if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) {
printk(KERN_ERR MSG_LOWMEM_TOO_SMALL,
pages_to_mb(highmem_pages));
highmem_pages = 0;
}
max_low_pfn -= highmem_pages;
}
#else
if (highmem_pages)
printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n");
#endif
}
#define MSG_HIGHMEM_TOO_SMALL \
"only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
#define MSG_HIGHMEM_TRIMMED \
"Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
/*
* We have more RAM than fits into lowmem - we try to put it into
* highmem, also taking the highmem=x boot parameter into account:
*/
static void __init highmem_pfn_init(void)
{
max_low_pfn = MAXMEM_PFN;
if (highmem_pages == -1)
highmem_pages = max_pfn - MAXMEM_PFN;
if (highmem_pages + MAXMEM_PFN < max_pfn)
max_pfn = MAXMEM_PFN + highmem_pages;
if (highmem_pages + MAXMEM_PFN > max_pfn) {
printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL,
pages_to_mb(max_pfn - MAXMEM_PFN),
pages_to_mb(highmem_pages));
highmem_pages = 0;
}
#ifndef CONFIG_HIGHMEM
/* Maximum memory usable is what is directly addressable */
printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20);
if (max_pfn > MAX_NONPAE_PFN)
printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n");
else
printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
max_pfn = MAXMEM_PFN;
#else /* !CONFIG_HIGHMEM */
#ifndef CONFIG_HIGHMEM64G
if (max_pfn > MAX_NONPAE_PFN) {
max_pfn = MAX_NONPAE_PFN;
printk(KERN_WARNING MSG_HIGHMEM_TRIMMED);
}
#endif /* !CONFIG_HIGHMEM64G */
#endif /* !CONFIG_HIGHMEM */
}
/*
* Determine low and high memory ranges:
*/
void __init find_low_pfn_range(void)
{
/* it could update max_pfn */
if (max_pfn <= MAXMEM_PFN)
lowmem_pfn_init();
else
highmem_pfn_init();
}
#ifndef CONFIG_NUMA
void __init initmem_init(void)
{
#ifdef CONFIG_HIGHMEM
highstart_pfn = highend_pfn = max_pfn;
if (max_pfn > max_low_pfn)
highstart_pfn = max_low_pfn;
printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
pages_to_mb(highend_pfn - highstart_pfn));
high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1;
#else
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1;
#endif
memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
#ifdef CONFIG_FLATMEM
max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn;
#endif
__vmalloc_start_set = true;
printk(KERN_NOTICE "%ldMB LOWMEM available.\n",
pages_to_mb(max_low_pfn));
setup_bootmem_allocator();
}
#endif /* !CONFIG_NUMA */
void __init setup_bootmem_allocator(void)
{
printk(KERN_INFO " mapped low ram: 0 - %08lx\n",
max_pfn_mapped<<PAGE_SHIFT);
printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT);
}
/*
* paging_init() sets up the page tables - note that the first 8MB are
* already mapped by head.S.
*
* This routines also unmaps the page at virtual kernel address 0, so
* that we can trap those pesky NULL-reference errors in the kernel.
*/
void __init paging_init(void)
{
pagetable_init();
__flush_tlb_all();
/*
* NOTE: at this point the bootmem allocator is fully available.
*/
olpc_dt_build_devicetree();
sparse_init();
zone_sizes_init();
}
/*
* Test if the WP bit works in supervisor mode. It isn't supported on 386's
* and also on some strange 486's. All 586+'s are OK. This used to involve
* black magic jumps to work around some nasty CPU bugs, but fortunately the
* switch to using exceptions got rid of all that.
*/
static void __init test_wp_bit(void)
{
char z = 0;
printk(KERN_INFO "Checking if this processor honours the WP bit even in supervisor mode...");
__set_fixmap(FIX_WP_TEST, __pa_symbol(empty_zero_page), PAGE_KERNEL_RO);
if (copy_to_kernel_nofault((char *)fix_to_virt(FIX_WP_TEST), &z, 1)) {
clear_fixmap(FIX_WP_TEST);
printk(KERN_CONT "Ok.\n");
return;
}
printk(KERN_CONT "No.\n");
panic("Linux doesn't support CPUs with broken WP.");
}
void __init mem_init(void)
{
pci_iommu_alloc();
#ifdef CONFIG_FLATMEM
BUG_ON(!mem_map);
#endif
/*
* With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to
* be done before memblock_free_all(). Memblock use free low memory for
* temporary data (see find_range_array()) and for this purpose can use
* pages that was already passed to the buddy allocator, hence marked as
* not accessible in the page tables when compiled with
* CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not
* important here.
*/
set_highmem_pages_init();
/* this will put all low memory onto the freelists */
memblock_free_all();
after_bootmem = 1;
x86_init.hyper.init_after_bootmem();
/*
* Check boundaries twice: Some fundamental inconsistencies can
* be detected at build time already.
*/
#define __FIXADDR_TOP (-PAGE_SIZE)
#ifdef CONFIG_HIGHMEM
BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE);
#endif
#define high_memory (-128UL << 20)
BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
#undef high_memory
#undef __FIXADDR_TOP
#ifdef CONFIG_HIGHMEM
BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START);
BUG_ON(VMALLOC_END > PKMAP_BASE);
#endif
BUG_ON(VMALLOC_START >= VMALLOC_END);
BUG_ON((unsigned long)high_memory > VMALLOC_START);
test_wp_bit();
}
int kernel_set_to_readonly __read_mostly;
static void mark_nxdata_nx(void)
{
/*
* When this called, init has already been executed and released,
* so everything past _etext should be NX.
*/
unsigned long start = PFN_ALIGN(_etext);
/*
* This comes from is_x86_32_kernel_text upper limit. Also HPAGE where used:
*/
unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start;
if (__supported_pte_mask & _PAGE_NX)
printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10);
set_memory_nx(start, size >> PAGE_SHIFT);
}
void mark_rodata_ro(void)
{
unsigned long start = PFN_ALIGN(_text);
unsigned long size = (unsigned long)__end_rodata - start;
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
pr_info("Write protecting kernel text and read-only data: %luk\n",
size >> 10);
kernel_set_to_readonly = 1;
#ifdef CONFIG_CPA_DEBUG
pr_info("Testing CPA: Reverting %lx-%lx\n", start, start + size);
set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
pr_info("Testing CPA: write protecting again\n");
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
#endif
mark_nxdata_nx();
}