374 lines
9.2 KiB
C
374 lines
9.2 KiB
C
/*
|
|
* linux/arch/i386/mm/pgtable.c
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/module.h>
|
|
#include <linux/quicklist.h>
|
|
|
|
#include <asm/system.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/fixmap.h>
|
|
#include <asm/e820.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
void show_mem(void)
|
|
{
|
|
int total = 0, reserved = 0;
|
|
int shared = 0, cached = 0;
|
|
int highmem = 0;
|
|
struct page *page;
|
|
pg_data_t *pgdat;
|
|
unsigned long i;
|
|
unsigned long flags;
|
|
|
|
printk(KERN_INFO "Mem-info:\n");
|
|
show_free_areas();
|
|
printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
|
|
for_each_online_pgdat(pgdat) {
|
|
pgdat_resize_lock(pgdat, &flags);
|
|
for (i = 0; i < pgdat->node_spanned_pages; ++i) {
|
|
page = pgdat_page_nr(pgdat, i);
|
|
total++;
|
|
if (PageHighMem(page))
|
|
highmem++;
|
|
if (PageReserved(page))
|
|
reserved++;
|
|
else if (PageSwapCache(page))
|
|
cached++;
|
|
else if (page_count(page))
|
|
shared += page_count(page) - 1;
|
|
}
|
|
pgdat_resize_unlock(pgdat, &flags);
|
|
}
|
|
printk(KERN_INFO "%d pages of RAM\n", total);
|
|
printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
|
|
printk(KERN_INFO "%d reserved pages\n", reserved);
|
|
printk(KERN_INFO "%d pages shared\n", shared);
|
|
printk(KERN_INFO "%d pages swap cached\n", cached);
|
|
|
|
printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
|
|
printk(KERN_INFO "%lu pages writeback\n",
|
|
global_page_state(NR_WRITEBACK));
|
|
printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
|
|
printk(KERN_INFO "%lu pages slab\n",
|
|
global_page_state(NR_SLAB_RECLAIMABLE) +
|
|
global_page_state(NR_SLAB_UNRECLAIMABLE));
|
|
printk(KERN_INFO "%lu pages pagetables\n",
|
|
global_page_state(NR_PAGETABLE));
|
|
}
|
|
|
|
/*
|
|
* Associate a virtual page frame with a given physical page frame
|
|
* and protection flags for that frame.
|
|
*/
|
|
static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pte_t *pte;
|
|
|
|
pgd = swapper_pg_dir + pgd_index(vaddr);
|
|
if (pgd_none(*pgd)) {
|
|
BUG();
|
|
return;
|
|
}
|
|
pud = pud_offset(pgd, vaddr);
|
|
if (pud_none(*pud)) {
|
|
BUG();
|
|
return;
|
|
}
|
|
pmd = pmd_offset(pud, vaddr);
|
|
if (pmd_none(*pmd)) {
|
|
BUG();
|
|
return;
|
|
}
|
|
pte = pte_offset_kernel(pmd, vaddr);
|
|
if (pgprot_val(flags))
|
|
/* <pfn,flags> stored as-is, to permit clearing entries */
|
|
set_pte(pte, pfn_pte(pfn, flags));
|
|
else
|
|
pte_clear(&init_mm, vaddr, pte);
|
|
|
|
/*
|
|
* It's enough to flush this one mapping.
|
|
* (PGE mappings get flushed as well)
|
|
*/
|
|
__flush_tlb_one(vaddr);
|
|
}
|
|
|
|
/*
|
|
* Associate a large virtual page frame with a given physical page frame
|
|
* and protection flags for that frame. pfn is for the base of the page,
|
|
* vaddr is what the page gets mapped to - both must be properly aligned.
|
|
* The pmd must already be instantiated. Assumes PAE mode.
|
|
*/
|
|
void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
|
|
if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
|
|
printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
|
|
return; /* BUG(); */
|
|
}
|
|
if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
|
|
printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
|
|
return; /* BUG(); */
|
|
}
|
|
pgd = swapper_pg_dir + pgd_index(vaddr);
|
|
if (pgd_none(*pgd)) {
|
|
printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
|
|
return; /* BUG(); */
|
|
}
|
|
pud = pud_offset(pgd, vaddr);
|
|
pmd = pmd_offset(pud, vaddr);
|
|
set_pmd(pmd, pfn_pmd(pfn, flags));
|
|
/*
|
|
* It's enough to flush this one mapping.
|
|
* (PGE mappings get flushed as well)
|
|
*/
|
|
__flush_tlb_one(vaddr);
|
|
}
|
|
|
|
static int fixmaps;
|
|
unsigned long __FIXADDR_TOP = 0xfffff000;
|
|
EXPORT_SYMBOL(__FIXADDR_TOP);
|
|
|
|
void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
|
|
{
|
|
unsigned long address = __fix_to_virt(idx);
|
|
|
|
if (idx >= __end_of_fixed_addresses) {
|
|
BUG();
|
|
return;
|
|
}
|
|
set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
|
|
fixmaps++;
|
|
}
|
|
|
|
/**
|
|
* reserve_top_address - reserves a hole in the top of kernel address space
|
|
* @reserve - size of hole to reserve
|
|
*
|
|
* Can be used to relocate the fixmap area and poke a hole in the top
|
|
* of kernel address space to make room for a hypervisor.
|
|
*/
|
|
void reserve_top_address(unsigned long reserve)
|
|
{
|
|
BUG_ON(fixmaps > 0);
|
|
printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
|
|
(int)-reserve);
|
|
__FIXADDR_TOP = -reserve - PAGE_SIZE;
|
|
__VMALLOC_RESERVE += reserve;
|
|
}
|
|
|
|
pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
|
|
{
|
|
return (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
|
|
}
|
|
|
|
struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
|
|
{
|
|
struct page *pte;
|
|
|
|
#ifdef CONFIG_HIGHPTE
|
|
pte = alloc_pages(GFP_KERNEL|__GFP_HIGHMEM|__GFP_REPEAT|__GFP_ZERO, 0);
|
|
#else
|
|
pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
|
|
#endif
|
|
return pte;
|
|
}
|
|
|
|
void pmd_ctor(void *pmd, struct kmem_cache *cache, unsigned long flags)
|
|
{
|
|
memset(pmd, 0, PTRS_PER_PMD*sizeof(pmd_t));
|
|
}
|
|
|
|
/*
|
|
* List of all pgd's needed for non-PAE so it can invalidate entries
|
|
* in both cached and uncached pgd's; not needed for PAE since the
|
|
* kernel pmd is shared. If PAE were not to share the pmd a similar
|
|
* tactic would be needed. This is essentially codepath-based locking
|
|
* against pageattr.c; it is the unique case in which a valid change
|
|
* of kernel pagetables can't be lazily synchronized by vmalloc faults.
|
|
* vmalloc faults work because attached pagetables are never freed.
|
|
* -- wli
|
|
*/
|
|
DEFINE_SPINLOCK(pgd_lock);
|
|
struct page *pgd_list;
|
|
|
|
static inline void pgd_list_add(pgd_t *pgd)
|
|
{
|
|
struct page *page = virt_to_page(pgd);
|
|
page->index = (unsigned long)pgd_list;
|
|
if (pgd_list)
|
|
set_page_private(pgd_list, (unsigned long)&page->index);
|
|
pgd_list = page;
|
|
set_page_private(page, (unsigned long)&pgd_list);
|
|
}
|
|
|
|
static inline void pgd_list_del(pgd_t *pgd)
|
|
{
|
|
struct page *next, **pprev, *page = virt_to_page(pgd);
|
|
next = (struct page *)page->index;
|
|
pprev = (struct page **)page_private(page);
|
|
*pprev = next;
|
|
if (next)
|
|
set_page_private(next, (unsigned long)pprev);
|
|
}
|
|
|
|
|
|
|
|
#if (PTRS_PER_PMD == 1)
|
|
/* Non-PAE pgd constructor */
|
|
void pgd_ctor(void *pgd)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/* !PAE, no pagetable sharing */
|
|
memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
|
|
|
|
spin_lock_irqsave(&pgd_lock, flags);
|
|
|
|
/* must happen under lock */
|
|
clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
|
|
swapper_pg_dir + USER_PTRS_PER_PGD,
|
|
KERNEL_PGD_PTRS);
|
|
paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
|
|
__pa(swapper_pg_dir) >> PAGE_SHIFT,
|
|
USER_PTRS_PER_PGD,
|
|
KERNEL_PGD_PTRS);
|
|
pgd_list_add(pgd);
|
|
spin_unlock_irqrestore(&pgd_lock, flags);
|
|
}
|
|
#else /* PTRS_PER_PMD > 1 */
|
|
/* PAE pgd constructor */
|
|
void pgd_ctor(void *pgd)
|
|
{
|
|
/* PAE, kernel PMD may be shared */
|
|
|
|
if (SHARED_KERNEL_PMD) {
|
|
clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
|
|
swapper_pg_dir + USER_PTRS_PER_PGD,
|
|
KERNEL_PGD_PTRS);
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
|
|
spin_lock_irqsave(&pgd_lock, flags);
|
|
pgd_list_add(pgd);
|
|
spin_unlock_irqrestore(&pgd_lock, flags);
|
|
}
|
|
}
|
|
#endif /* PTRS_PER_PMD */
|
|
|
|
void pgd_dtor(void *pgd)
|
|
{
|
|
unsigned long flags; /* can be called from interrupt context */
|
|
|
|
if (SHARED_KERNEL_PMD)
|
|
return;
|
|
|
|
paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
|
|
spin_lock_irqsave(&pgd_lock, flags);
|
|
pgd_list_del(pgd);
|
|
spin_unlock_irqrestore(&pgd_lock, flags);
|
|
}
|
|
|
|
#define UNSHARED_PTRS_PER_PGD \
|
|
(SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
|
|
|
|
/* If we allocate a pmd for part of the kernel address space, then
|
|
make sure its initialized with the appropriate kernel mappings.
|
|
Otherwise use a cached zeroed pmd. */
|
|
static pmd_t *pmd_cache_alloc(int idx)
|
|
{
|
|
pmd_t *pmd;
|
|
|
|
if (idx >= USER_PTRS_PER_PGD) {
|
|
pmd = (pmd_t *)__get_free_page(GFP_KERNEL);
|
|
|
|
if (pmd)
|
|
memcpy(pmd,
|
|
(void *)pgd_page_vaddr(swapper_pg_dir[idx]),
|
|
sizeof(pmd_t) * PTRS_PER_PMD);
|
|
} else
|
|
pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
|
|
|
|
return pmd;
|
|
}
|
|
|
|
static void pmd_cache_free(pmd_t *pmd, int idx)
|
|
{
|
|
if (idx >= USER_PTRS_PER_PGD)
|
|
free_page((unsigned long)pmd);
|
|
else
|
|
kmem_cache_free(pmd_cache, pmd);
|
|
}
|
|
|
|
pgd_t *pgd_alloc(struct mm_struct *mm)
|
|
{
|
|
int i;
|
|
pgd_t *pgd = quicklist_alloc(0, GFP_KERNEL, pgd_ctor);
|
|
|
|
if (PTRS_PER_PMD == 1 || !pgd)
|
|
return pgd;
|
|
|
|
for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
|
|
pmd_t *pmd = pmd_cache_alloc(i);
|
|
|
|
if (!pmd)
|
|
goto out_oom;
|
|
|
|
paravirt_alloc_pd(__pa(pmd) >> PAGE_SHIFT);
|
|
set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
|
|
}
|
|
return pgd;
|
|
|
|
out_oom:
|
|
for (i--; i >= 0; i--) {
|
|
pgd_t pgdent = pgd[i];
|
|
void* pmd = (void *)__va(pgd_val(pgdent)-1);
|
|
paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
|
|
pmd_cache_free(pmd, i);
|
|
}
|
|
quicklist_free(0, pgd_dtor, pgd);
|
|
return NULL;
|
|
}
|
|
|
|
void pgd_free(pgd_t *pgd)
|
|
{
|
|
int i;
|
|
|
|
/* in the PAE case user pgd entries are overwritten before usage */
|
|
if (PTRS_PER_PMD > 1)
|
|
for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
|
|
pgd_t pgdent = pgd[i];
|
|
void* pmd = (void *)__va(pgd_val(pgdent)-1);
|
|
paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
|
|
pmd_cache_free(pmd, i);
|
|
}
|
|
/* in the non-PAE case, free_pgtables() clears user pgd entries */
|
|
quicklist_free(0, pgd_dtor, pgd);
|
|
}
|
|
|
|
void check_pgt_cache(void)
|
|
{
|
|
quicklist_trim(0, pgd_dtor, 25, 16);
|
|
}
|
|
|