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linux-next/arch/x86/mm/init_64.c
Paul Gortmaker 4b599fedb7 x86/mm: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace accordingly where needed.

Note that some bool/obj-y instances remain since module.h is
the header for some exception table entry stuff, and for things
like __init_or_module (code that is tossed when MODULES=n).

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160714001901.31603-3-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 13:04:20 +02:00

1309 lines
32 KiB
C

/*
* linux/arch/x86_64/mm/init.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 2000 Pavel Machek <pavel@ucw.cz>
* Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
*/
#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/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/proc_fs.h>
#include <linux/pci.h>
#include <linux/pfn.h>
#include <linux/poison.h>
#include <linux/dma-mapping.h>
#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/memremap.h>
#include <linux/nmi.h>
#include <linux/gfp.h>
#include <linux/kcore.h>
#include <asm/processor.h>
#include <asm/bios_ebda.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/fixmap.h>
#include <asm/e820.h>
#include <asm/apic.h>
#include <asm/tlb.h>
#include <asm/mmu_context.h>
#include <asm/proto.h>
#include <asm/smp.h>
#include <asm/sections.h>
#include <asm/kdebug.h>
#include <asm/numa.h>
#include <asm/cacheflush.h>
#include <asm/init.h>
#include <asm/uv/uv.h>
#include <asm/setup.h>
#include "mm_internal.h"
#include "ident_map.c"
/*
* NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
* physical space so we can cache the place of the first one and move
* around without checking the pgd every time.
*/
pteval_t __supported_pte_mask __read_mostly = ~0;
EXPORT_SYMBOL_GPL(__supported_pte_mask);
int force_personality32;
/*
* noexec32=on|off
* Control non executable heap for 32bit processes.
* To control the stack too use noexec=off
*
* on PROT_READ does not imply PROT_EXEC for 32-bit processes (default)
* off PROT_READ implies PROT_EXEC
*/
static int __init nonx32_setup(char *str)
{
if (!strcmp(str, "on"))
force_personality32 &= ~READ_IMPLIES_EXEC;
else if (!strcmp(str, "off"))
force_personality32 |= READ_IMPLIES_EXEC;
return 1;
}
__setup("noexec32=", nonx32_setup);
/*
* When memory was added/removed make sure all the processes MM have
* suitable PGD entries in the local PGD level page.
*/
void sync_global_pgds(unsigned long start, unsigned long end, int removed)
{
unsigned long address;
for (address = start; address <= end; address += PGDIR_SIZE) {
const pgd_t *pgd_ref = pgd_offset_k(address);
struct page *page;
/*
* When it is called after memory hot remove, pgd_none()
* returns true. In this case (removed == 1), we must clear
* the PGD entries in the local PGD level page.
*/
if (pgd_none(*pgd_ref) && !removed)
continue;
spin_lock(&pgd_lock);
list_for_each_entry(page, &pgd_list, lru) {
pgd_t *pgd;
spinlock_t *pgt_lock;
pgd = (pgd_t *)page_address(page) + pgd_index(address);
/* the pgt_lock only for Xen */
pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
spin_lock(pgt_lock);
if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
BUG_ON(pgd_page_vaddr(*pgd)
!= pgd_page_vaddr(*pgd_ref));
if (removed) {
if (pgd_none(*pgd_ref) && !pgd_none(*pgd))
pgd_clear(pgd);
} else {
if (pgd_none(*pgd))
set_pgd(pgd, *pgd_ref);
}
spin_unlock(pgt_lock);
}
spin_unlock(&pgd_lock);
}
}
/*
* NOTE: This function is marked __ref because it calls __init function
* (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0.
*/
static __ref void *spp_getpage(void)
{
void *ptr;
if (after_bootmem)
ptr = (void *) get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK);
else
ptr = alloc_bootmem_pages(PAGE_SIZE);
if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
panic("set_pte_phys: cannot allocate page data %s\n",
after_bootmem ? "after bootmem" : "");
}
pr_debug("spp_getpage %p\n", ptr);
return ptr;
}
static pud_t *fill_pud(pgd_t *pgd, unsigned long vaddr)
{
if (pgd_none(*pgd)) {
pud_t *pud = (pud_t *)spp_getpage();
pgd_populate(&init_mm, pgd, pud);
if (pud != pud_offset(pgd, 0))
printk(KERN_ERR "PAGETABLE BUG #00! %p <-> %p\n",
pud, pud_offset(pgd, 0));
}
return pud_offset(pgd, vaddr);
}
static pmd_t *fill_pmd(pud_t *pud, unsigned long vaddr)
{
if (pud_none(*pud)) {
pmd_t *pmd = (pmd_t *) spp_getpage();
pud_populate(&init_mm, pud, pmd);
if (pmd != pmd_offset(pud, 0))
printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
pmd, pmd_offset(pud, 0));
}
return pmd_offset(pud, vaddr);
}
static pte_t *fill_pte(pmd_t *pmd, unsigned long vaddr)
{
if (pmd_none(*pmd)) {
pte_t *pte = (pte_t *) spp_getpage();
pmd_populate_kernel(&init_mm, pmd, pte);
if (pte != pte_offset_kernel(pmd, 0))
printk(KERN_ERR "PAGETABLE BUG #02!\n");
}
return pte_offset_kernel(pmd, vaddr);
}
void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte)
{
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pud = pud_page + pud_index(vaddr);
pmd = fill_pmd(pud, vaddr);
pte = fill_pte(pmd, vaddr);
set_pte(pte, new_pte);
/*
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
__flush_tlb_one(vaddr);
}
void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
{
pgd_t *pgd;
pud_t *pud_page;
pr_debug("set_pte_vaddr %lx to %lx\n", vaddr, native_pte_val(pteval));
pgd = pgd_offset_k(vaddr);
if (pgd_none(*pgd)) {
printk(KERN_ERR
"PGD FIXMAP MISSING, it should be setup in head.S!\n");
return;
}
pud_page = (pud_t*)pgd_page_vaddr(*pgd);
set_pte_vaddr_pud(pud_page, vaddr, pteval);
}
pmd_t * __init populate_extra_pmd(unsigned long vaddr)
{
pgd_t *pgd;
pud_t *pud;
pgd = pgd_offset_k(vaddr);
pud = fill_pud(pgd, vaddr);
return fill_pmd(pud, vaddr);
}
pte_t * __init populate_extra_pte(unsigned long vaddr)
{
pmd_t *pmd;
pmd = populate_extra_pmd(vaddr);
return fill_pte(pmd, vaddr);
}
/*
* Create large page table mappings for a range of physical addresses.
*/
static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
enum page_cache_mode cache)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pgprot_t prot;
pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
pgd = pgd_offset_k((unsigned long)__va(phys));
if (pgd_none(*pgd)) {
pud = (pud_t *) spp_getpage();
set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE |
_PAGE_USER));
}
pud = pud_offset(pgd, (unsigned long)__va(phys));
if (pud_none(*pud)) {
pmd = (pmd_t *) spp_getpage();
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE |
_PAGE_USER));
}
pmd = pmd_offset(pud, phys);
BUG_ON(!pmd_none(*pmd));
set_pmd(pmd, __pmd(phys | pgprot_val(prot)));
}
}
void __init init_extra_mapping_wb(unsigned long phys, unsigned long size)
{
__init_extra_mapping(phys, size, _PAGE_CACHE_MODE_WB);
}
void __init init_extra_mapping_uc(unsigned long phys, unsigned long size)
{
__init_extra_mapping(phys, size, _PAGE_CACHE_MODE_UC);
}
/*
* The head.S code sets up the kernel high mapping:
*
* from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
*
* phys_base holds the negative offset to the kernel, which is added
* to the compile time generated pmds. This results in invalid pmds up
* to the point where we hit the physaddr 0 mapping.
*
* We limit the mappings to the region from _text to _brk_end. _brk_end
* is rounded up to the 2MB boundary. This catches the invalid pmds as
* well, as they are located before _text:
*/
void __init cleanup_highmap(void)
{
unsigned long vaddr = __START_KERNEL_map;
unsigned long vaddr_end = __START_KERNEL_map + KERNEL_IMAGE_SIZE;
unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1;
pmd_t *pmd = level2_kernel_pgt;
/*
* Native path, max_pfn_mapped is not set yet.
* Xen has valid max_pfn_mapped set in
* arch/x86/xen/mmu.c:xen_setup_kernel_pagetable().
*/
if (max_pfn_mapped)
vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT);
for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) {
if (pmd_none(*pmd))
continue;
if (vaddr < (unsigned long) _text || vaddr > end)
set_pmd(pmd, __pmd(0));
}
}
static unsigned long __meminit
phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
pgprot_t prot)
{
unsigned long pages = 0, next;
unsigned long last_map_addr = end;
int i;
pte_t *pte = pte_page + pte_index(addr);
for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) {
next = (addr & PAGE_MASK) + PAGE_SIZE;
if (addr >= end) {
if (!after_bootmem &&
!e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) &&
!e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN))
set_pte(pte, __pte(0));
continue;
}
/*
* We will re-use the existing mapping.
* Xen for example has some special requirements, like mapping
* pagetable pages as RO. So assume someone who pre-setup
* these mappings are more intelligent.
*/
if (pte_val(*pte)) {
if (!after_bootmem)
pages++;
continue;
}
if (0)
printk(" pte=%p addr=%lx pte=%016lx\n",
pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte);
pages++;
set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot));
last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE;
}
update_page_count(PG_LEVEL_4K, pages);
return last_map_addr;
}
static unsigned long __meminit
phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
unsigned long page_size_mask, pgprot_t prot)
{
unsigned long pages = 0, next;
unsigned long last_map_addr = end;
int i = pmd_index(address);
for (; i < PTRS_PER_PMD; i++, address = next) {
pmd_t *pmd = pmd_page + pmd_index(address);
pte_t *pte;
pgprot_t new_prot = prot;
next = (address & PMD_MASK) + PMD_SIZE;
if (address >= end) {
if (!after_bootmem &&
!e820_any_mapped(address & PMD_MASK, next, E820_RAM) &&
!e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN))
set_pmd(pmd, __pmd(0));
continue;
}
if (pmd_val(*pmd)) {
if (!pmd_large(*pmd)) {
spin_lock(&init_mm.page_table_lock);
pte = (pte_t *)pmd_page_vaddr(*pmd);
last_map_addr = phys_pte_init(pte, address,
end, prot);
spin_unlock(&init_mm.page_table_lock);
continue;
}
/*
* If we are ok with PG_LEVEL_2M mapping, then we will
* use the existing mapping,
*
* Otherwise, we will split the large page mapping but
* use the same existing protection bits except for
* large page, so that we don't violate Intel's TLB
* Application note (317080) which says, while changing
* the page sizes, new and old translations should
* not differ with respect to page frame and
* attributes.
*/
if (page_size_mask & (1 << PG_LEVEL_2M)) {
if (!after_bootmem)
pages++;
last_map_addr = next;
continue;
}
new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
}
if (page_size_mask & (1<<PG_LEVEL_2M)) {
pages++;
spin_lock(&init_mm.page_table_lock);
set_pte((pte_t *)pmd,
pfn_pte((address & PMD_MASK) >> PAGE_SHIFT,
__pgprot(pgprot_val(prot) | _PAGE_PSE)));
spin_unlock(&init_mm.page_table_lock);
last_map_addr = next;
continue;
}
pte = alloc_low_page();
last_map_addr = phys_pte_init(pte, address, end, new_prot);
spin_lock(&init_mm.page_table_lock);
pmd_populate_kernel(&init_mm, pmd, pte);
spin_unlock(&init_mm.page_table_lock);
}
update_page_count(PG_LEVEL_2M, pages);
return last_map_addr;
}
static unsigned long __meminit
phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
unsigned long page_size_mask)
{
unsigned long pages = 0, next;
unsigned long last_map_addr = end;
int i = pud_index(addr);
for (; i < PTRS_PER_PUD; i++, addr = next) {
pud_t *pud = pud_page + pud_index(addr);
pmd_t *pmd;
pgprot_t prot = PAGE_KERNEL;
next = (addr & PUD_MASK) + PUD_SIZE;
if (addr >= end) {
if (!after_bootmem &&
!e820_any_mapped(addr & PUD_MASK, next, E820_RAM) &&
!e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN))
set_pud(pud, __pud(0));
continue;
}
if (pud_val(*pud)) {
if (!pud_large(*pud)) {
pmd = pmd_offset(pud, 0);
last_map_addr = phys_pmd_init(pmd, addr, end,
page_size_mask, prot);
__flush_tlb_all();
continue;
}
/*
* If we are ok with PG_LEVEL_1G mapping, then we will
* use the existing mapping.
*
* Otherwise, we will split the gbpage mapping but use
* the same existing protection bits except for large
* page, so that we don't violate Intel's TLB
* Application note (317080) which says, while changing
* the page sizes, new and old translations should
* not differ with respect to page frame and
* attributes.
*/
if (page_size_mask & (1 << PG_LEVEL_1G)) {
if (!after_bootmem)
pages++;
last_map_addr = next;
continue;
}
prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
}
if (page_size_mask & (1<<PG_LEVEL_1G)) {
pages++;
spin_lock(&init_mm.page_table_lock);
set_pte((pte_t *)pud,
pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT,
PAGE_KERNEL_LARGE));
spin_unlock(&init_mm.page_table_lock);
last_map_addr = next;
continue;
}
pmd = alloc_low_page();
last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
prot);
spin_lock(&init_mm.page_table_lock);
pud_populate(&init_mm, pud, pmd);
spin_unlock(&init_mm.page_table_lock);
}
__flush_tlb_all();
update_page_count(PG_LEVEL_1G, pages);
return last_map_addr;
}
unsigned long __meminit
kernel_physical_mapping_init(unsigned long start,
unsigned long end,
unsigned long page_size_mask)
{
bool pgd_changed = false;
unsigned long next, last_map_addr = end;
unsigned long addr;
start = (unsigned long)__va(start);
end = (unsigned long)__va(end);
addr = start;
for (; start < end; start = next) {
pgd_t *pgd = pgd_offset_k(start);
pud_t *pud;
next = (start & PGDIR_MASK) + PGDIR_SIZE;
if (pgd_val(*pgd)) {
pud = (pud_t *)pgd_page_vaddr(*pgd);
last_map_addr = phys_pud_init(pud, __pa(start),
__pa(end), page_size_mask);
continue;
}
pud = alloc_low_page();
last_map_addr = phys_pud_init(pud, __pa(start), __pa(end),
page_size_mask);
spin_lock(&init_mm.page_table_lock);
pgd_populate(&init_mm, pgd, pud);
spin_unlock(&init_mm.page_table_lock);
pgd_changed = true;
}
if (pgd_changed)
sync_global_pgds(addr, end - 1, 0);
__flush_tlb_all();
return last_map_addr;
}
#ifndef CONFIG_NUMA
void __init initmem_init(void)
{
memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
}
#endif
void __init paging_init(void)
{
sparse_memory_present_with_active_regions(MAX_NUMNODES);
sparse_init();
/*
* clear the default setting with node 0
* note: don't use nodes_clear here, that is really clearing when
* numa support is not compiled in, and later node_set_state
* will not set it back.
*/
node_clear_state(0, N_MEMORY);
if (N_MEMORY != N_NORMAL_MEMORY)
node_clear_state(0, N_NORMAL_MEMORY);
zone_sizes_init();
}
/*
* Memory hotplug specific functions
*/
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
* updating.
*/
static void update_end_of_memory_vars(u64 start, u64 size)
{
unsigned long end_pfn = PFN_UP(start + size);
if (end_pfn > max_pfn) {
max_pfn = end_pfn;
max_low_pfn = end_pfn;
high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
}
}
/*
* Memory is added always to NORMAL zone. This means you will never get
* additional DMA/DMA32 memory.
*/
int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
{
struct pglist_data *pgdat = NODE_DATA(nid);
struct zone *zone = pgdat->node_zones +
zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
int ret;
init_memory_mapping(start, start + size);
ret = __add_pages(nid, zone, start_pfn, nr_pages);
WARN_ON_ONCE(ret);
/* update max_pfn, max_low_pfn and high_memory */
update_end_of_memory_vars(start, size);
return ret;
}
EXPORT_SYMBOL_GPL(arch_add_memory);
#define PAGE_INUSE 0xFD
static void __meminit free_pagetable(struct page *page, int order)
{
unsigned long magic;
unsigned int nr_pages = 1 << order;
struct vmem_altmap *altmap = to_vmem_altmap((unsigned long) page);
if (altmap) {
vmem_altmap_free(altmap, nr_pages);
return;
}
/* bootmem page has reserved flag */
if (PageReserved(page)) {
__ClearPageReserved(page);
magic = (unsigned long)page->lru.next;
if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
while (nr_pages--)
put_page_bootmem(page++);
} else
while (nr_pages--)
free_reserved_page(page++);
} else
free_pages((unsigned long)page_address(page), order);
}
static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
{
pte_t *pte;
int i;
for (i = 0; i < PTRS_PER_PTE; i++) {
pte = pte_start + i;
if (pte_val(*pte))
return;
}
/* free a pte talbe */
free_pagetable(pmd_page(*pmd), 0);
spin_lock(&init_mm.page_table_lock);
pmd_clear(pmd);
spin_unlock(&init_mm.page_table_lock);
}
static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
{
pmd_t *pmd;
int i;
for (i = 0; i < PTRS_PER_PMD; i++) {
pmd = pmd_start + i;
if (pmd_val(*pmd))
return;
}
/* free a pmd talbe */
free_pagetable(pud_page(*pud), 0);
spin_lock(&init_mm.page_table_lock);
pud_clear(pud);
spin_unlock(&init_mm.page_table_lock);
}
/* Return true if pgd is changed, otherwise return false. */
static bool __meminit free_pud_table(pud_t *pud_start, pgd_t *pgd)
{
pud_t *pud;
int i;
for (i = 0; i < PTRS_PER_PUD; i++) {
pud = pud_start + i;
if (pud_val(*pud))
return false;
}
/* free a pud table */
free_pagetable(pgd_page(*pgd), 0);
spin_lock(&init_mm.page_table_lock);
pgd_clear(pgd);
spin_unlock(&init_mm.page_table_lock);
return true;
}
static void __meminit
remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
bool direct)
{
unsigned long next, pages = 0;
pte_t *pte;
void *page_addr;
phys_addr_t phys_addr;
pte = pte_start + pte_index(addr);
for (; addr < end; addr = next, pte++) {
next = (addr + PAGE_SIZE) & PAGE_MASK;
if (next > end)
next = end;
if (!pte_present(*pte))
continue;
/*
* We mapped [0,1G) memory as identity mapping when
* initializing, in arch/x86/kernel/head_64.S. These
* pagetables cannot be removed.
*/
phys_addr = pte_val(*pte) + (addr & PAGE_MASK);
if (phys_addr < (phys_addr_t)0x40000000)
return;
if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) {
/*
* Do not free direct mapping pages since they were
* freed when offlining, or simplely not in use.
*/
if (!direct)
free_pagetable(pte_page(*pte), 0);
spin_lock(&init_mm.page_table_lock);
pte_clear(&init_mm, addr, pte);
spin_unlock(&init_mm.page_table_lock);
/* For non-direct mapping, pages means nothing. */
pages++;
} else {
/*
* If we are here, we are freeing vmemmap pages since
* direct mapped memory ranges to be freed are aligned.
*
* If we are not removing the whole page, it means
* other page structs in this page are being used and
* we canot remove them. So fill the unused page_structs
* with 0xFD, and remove the page when it is wholly
* filled with 0xFD.
*/
memset((void *)addr, PAGE_INUSE, next - addr);
page_addr = page_address(pte_page(*pte));
if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
free_pagetable(pte_page(*pte), 0);
spin_lock(&init_mm.page_table_lock);
pte_clear(&init_mm, addr, pte);
spin_unlock(&init_mm.page_table_lock);
}
}
}
/* Call free_pte_table() in remove_pmd_table(). */
flush_tlb_all();
if (direct)
update_page_count(PG_LEVEL_4K, -pages);
}
static void __meminit
remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
bool direct)
{
unsigned long next, pages = 0;
pte_t *pte_base;
pmd_t *pmd;
void *page_addr;
pmd = pmd_start + pmd_index(addr);
for (; addr < end; addr = next, pmd++) {
next = pmd_addr_end(addr, end);
if (!pmd_present(*pmd))
continue;
if (pmd_large(*pmd)) {
if (IS_ALIGNED(addr, PMD_SIZE) &&
IS_ALIGNED(next, PMD_SIZE)) {
if (!direct)
free_pagetable(pmd_page(*pmd),
get_order(PMD_SIZE));
spin_lock(&init_mm.page_table_lock);
pmd_clear(pmd);
spin_unlock(&init_mm.page_table_lock);
pages++;
} else {
/* If here, we are freeing vmemmap pages. */
memset((void *)addr, PAGE_INUSE, next - addr);
page_addr = page_address(pmd_page(*pmd));
if (!memchr_inv(page_addr, PAGE_INUSE,
PMD_SIZE)) {
free_pagetable(pmd_page(*pmd),
get_order(PMD_SIZE));
spin_lock(&init_mm.page_table_lock);
pmd_clear(pmd);
spin_unlock(&init_mm.page_table_lock);
}
}
continue;
}
pte_base = (pte_t *)pmd_page_vaddr(*pmd);
remove_pte_table(pte_base, addr, next, direct);
free_pte_table(pte_base, pmd);
}
/* Call free_pmd_table() in remove_pud_table(). */
if (direct)
update_page_count(PG_LEVEL_2M, -pages);
}
static void __meminit
remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
bool direct)
{
unsigned long next, pages = 0;
pmd_t *pmd_base;
pud_t *pud;
void *page_addr;
pud = pud_start + pud_index(addr);
for (; addr < end; addr = next, pud++) {
next = pud_addr_end(addr, end);
if (!pud_present(*pud))
continue;
if (pud_large(*pud)) {
if (IS_ALIGNED(addr, PUD_SIZE) &&
IS_ALIGNED(next, PUD_SIZE)) {
if (!direct)
free_pagetable(pud_page(*pud),
get_order(PUD_SIZE));
spin_lock(&init_mm.page_table_lock);
pud_clear(pud);
spin_unlock(&init_mm.page_table_lock);
pages++;
} else {
/* If here, we are freeing vmemmap pages. */
memset((void *)addr, PAGE_INUSE, next - addr);
page_addr = page_address(pud_page(*pud));
if (!memchr_inv(page_addr, PAGE_INUSE,
PUD_SIZE)) {
free_pagetable(pud_page(*pud),
get_order(PUD_SIZE));
spin_lock(&init_mm.page_table_lock);
pud_clear(pud);
spin_unlock(&init_mm.page_table_lock);
}
}
continue;
}
pmd_base = (pmd_t *)pud_page_vaddr(*pud);
remove_pmd_table(pmd_base, addr, next, direct);
free_pmd_table(pmd_base, pud);
}
if (direct)
update_page_count(PG_LEVEL_1G, -pages);
}
/* start and end are both virtual address. */
static void __meminit
remove_pagetable(unsigned long start, unsigned long end, bool direct)
{
unsigned long next;
unsigned long addr;
pgd_t *pgd;
pud_t *pud;
bool pgd_changed = false;
for (addr = start; addr < end; addr = next) {
next = pgd_addr_end(addr, end);
pgd = pgd_offset_k(addr);
if (!pgd_present(*pgd))
continue;
pud = (pud_t *)pgd_page_vaddr(*pgd);
remove_pud_table(pud, addr, next, direct);
if (free_pud_table(pud, pgd))
pgd_changed = true;
}
if (pgd_changed)
sync_global_pgds(start, end - 1, 1);
flush_tlb_all();
}
void __ref vmemmap_free(unsigned long start, unsigned long end)
{
remove_pagetable(start, end, false);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
static void __meminit
kernel_physical_mapping_remove(unsigned long start, unsigned long end)
{
start = (unsigned long)__va(start);
end = (unsigned long)__va(end);
remove_pagetable(start, end, true);
}
int __ref arch_remove_memory(u64 start, u64 size)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
struct page *page = pfn_to_page(start_pfn);
struct vmem_altmap *altmap;
struct zone *zone;
int ret;
/* With altmap the first mapped page is offset from @start */
altmap = to_vmem_altmap((unsigned long) page);
if (altmap)
page += vmem_altmap_offset(altmap);
zone = page_zone(page);
ret = __remove_pages(zone, start_pfn, nr_pages);
WARN_ON_ONCE(ret);
kernel_physical_mapping_remove(start, start + size);
return ret;
}
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */
static struct kcore_list kcore_vsyscall;
static void __init register_page_bootmem_info(void)
{
#ifdef CONFIG_NUMA
int i;
for_each_online_node(i)
register_page_bootmem_info_node(NODE_DATA(i));
#endif
}
void __init mem_init(void)
{
pci_iommu_alloc();
/* clear_bss() already clear the empty_zero_page */
register_page_bootmem_info();
/* this will put all memory onto the freelists */
free_all_bootmem();
after_bootmem = 1;
/* Register memory areas for /proc/kcore */
kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR,
PAGE_SIZE, KCORE_OTHER);
mem_init_print_info(NULL);
}
const int rodata_test_data = 0xC3;
EXPORT_SYMBOL_GPL(rodata_test_data);
int kernel_set_to_readonly;
void set_kernel_text_rw(void)
{
unsigned long start = PFN_ALIGN(_text);
unsigned long end = PFN_ALIGN(__stop___ex_table);
if (!kernel_set_to_readonly)
return;
pr_debug("Set kernel text: %lx - %lx for read write\n",
start, end);
/*
* Make the kernel identity mapping for text RW. Kernel text
* mapping will always be RO. Refer to the comment in
* static_protections() in pageattr.c
*/
set_memory_rw(start, (end - start) >> PAGE_SHIFT);
}
void set_kernel_text_ro(void)
{
unsigned long start = PFN_ALIGN(_text);
unsigned long end = PFN_ALIGN(__stop___ex_table);
if (!kernel_set_to_readonly)
return;
pr_debug("Set kernel text: %lx - %lx for read only\n",
start, end);
/*
* Set the kernel identity mapping for text RO.
*/
set_memory_ro(start, (end - start) >> PAGE_SHIFT);
}
void mark_rodata_ro(void)
{
unsigned long start = PFN_ALIGN(_text);
unsigned long rodata_start = PFN_ALIGN(__start_rodata);
unsigned long end = (unsigned long) &__end_rodata_hpage_align;
unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
unsigned long all_end;
printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
(end - start) >> 10);
set_memory_ro(start, (end - start) >> PAGE_SHIFT);
kernel_set_to_readonly = 1;
/*
* The rodata/data/bss/brk section (but not the kernel text!)
* should also be not-executable.
*
* We align all_end to PMD_SIZE because the existing mapping
* is a full PMD. If we would align _brk_end to PAGE_SIZE we
* split the PMD and the reminder between _brk_end and the end
* of the PMD will remain mapped executable.
*
* Any PMD which was setup after the one which covers _brk_end
* has been zapped already via cleanup_highmem().
*/
all_end = roundup((unsigned long)_brk_end, PMD_SIZE);
set_memory_nx(text_end, (all_end - text_end) >> PAGE_SHIFT);
rodata_test();
#ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
set_memory_rw(start, (end-start) >> PAGE_SHIFT);
printk(KERN_INFO "Testing CPA: again\n");
set_memory_ro(start, (end-start) >> PAGE_SHIFT);
#endif
free_init_pages("unused kernel",
(unsigned long) __va(__pa_symbol(text_end)),
(unsigned long) __va(__pa_symbol(rodata_start)));
free_init_pages("unused kernel",
(unsigned long) __va(__pa_symbol(rodata_end)),
(unsigned long) __va(__pa_symbol(_sdata)));
debug_checkwx();
}
int kern_addr_valid(unsigned long addr)
{
unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
if (above != 0 && above != -1UL)
return 0;
pgd = pgd_offset_k(addr);
if (pgd_none(*pgd))
return 0;
pud = pud_offset(pgd, addr);
if (pud_none(*pud))
return 0;
if (pud_large(*pud))
return pfn_valid(pud_pfn(*pud));
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd))
return 0;
if (pmd_large(*pmd))
return pfn_valid(pmd_pfn(*pmd));
pte = pte_offset_kernel(pmd, addr);
if (pte_none(*pte))
return 0;
return pfn_valid(pte_pfn(*pte));
}
static unsigned long probe_memory_block_size(void)
{
unsigned long bz = MIN_MEMORY_BLOCK_SIZE;
/* if system is UV or has 64GB of RAM or more, use large blocks */
if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30)))
bz = 2UL << 30; /* 2GB */
pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20);
return bz;
}
static unsigned long memory_block_size_probed;
unsigned long memory_block_size_bytes(void)
{
if (!memory_block_size_probed)
memory_block_size_probed = probe_memory_block_size();
return memory_block_size_probed;
}
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
* Initialise the sparsemem vmemmap using huge-pages at the PMD level.
*/
static long __meminitdata addr_start, addr_end;
static void __meminitdata *p_start, *p_end;
static int __meminitdata node_start;
static int __meminit vmemmap_populate_hugepages(unsigned long start,
unsigned long end, int node, struct vmem_altmap *altmap)
{
unsigned long addr;
unsigned long next;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
for (addr = start; addr < end; addr = next) {
next = pmd_addr_end(addr, end);
pgd = vmemmap_pgd_populate(addr, node);
if (!pgd)
return -ENOMEM;
pud = vmemmap_pud_populate(pgd, addr, node);
if (!pud)
return -ENOMEM;
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
void *p;
p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
if (p) {
pte_t entry;
entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
PAGE_KERNEL_LARGE);
set_pmd(pmd, __pmd(pte_val(entry)));
/* check to see if we have contiguous blocks */
if (p_end != p || node_start != node) {
if (p_start)
pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
addr_start, addr_end-1, p_start, p_end-1, node_start);
addr_start = addr;
node_start = node;
p_start = p;
}
addr_end = addr + PMD_SIZE;
p_end = p + PMD_SIZE;
continue;
} else if (altmap)
return -ENOMEM; /* no fallback */
} else if (pmd_large(*pmd)) {
vmemmap_verify((pte_t *)pmd, node, addr, next);
continue;
}
pr_warn_once("vmemmap: falling back to regular page backing\n");
if (vmemmap_populate_basepages(addr, next, node))
return -ENOMEM;
}
return 0;
}
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
{
struct vmem_altmap *altmap = to_vmem_altmap(start);
int err;
if (boot_cpu_has(X86_FEATURE_PSE))
err = vmemmap_populate_hugepages(start, end, node, altmap);
else if (altmap) {
pr_err_once("%s: no cpu support for altmap allocations\n",
__func__);
err = -ENOMEM;
} else
err = vmemmap_populate_basepages(start, end, node);
if (!err)
sync_global_pgds(start, end - 1, 0);
return err;
}
#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_HAVE_BOOTMEM_INFO_NODE)
void register_page_bootmem_memmap(unsigned long section_nr,
struct page *start_page, unsigned long size)
{
unsigned long addr = (unsigned long)start_page;
unsigned long end = (unsigned long)(start_page + size);
unsigned long next;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
unsigned int nr_pages;
struct page *page;
for (; addr < end; addr = next) {
pte_t *pte = NULL;
pgd = pgd_offset_k(addr);
if (pgd_none(*pgd)) {
next = (addr + PAGE_SIZE) & PAGE_MASK;
continue;
}
get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
pud = pud_offset(pgd, addr);
if (pud_none(*pud)) {
next = (addr + PAGE_SIZE) & PAGE_MASK;
continue;
}
get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
if (!boot_cpu_has(X86_FEATURE_PSE)) {
next = (addr + PAGE_SIZE) & PAGE_MASK;
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd))
continue;
get_page_bootmem(section_nr, pmd_page(*pmd),
MIX_SECTION_INFO);
pte = pte_offset_kernel(pmd, addr);
if (pte_none(*pte))
continue;
get_page_bootmem(section_nr, pte_page(*pte),
SECTION_INFO);
} else {
next = pmd_addr_end(addr, end);
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd))
continue;
nr_pages = 1 << (get_order(PMD_SIZE));
page = pmd_page(*pmd);
while (nr_pages--)
get_page_bootmem(section_nr, page++,
SECTION_INFO);
}
}
}
#endif
void __meminit vmemmap_populate_print_last(void)
{
if (p_start) {
pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
addr_start, addr_end-1, p_start, p_end-1, node_start);
p_start = NULL;
p_end = NULL;
node_start = 0;
}
}
#endif