/*
* 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 <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;
#ifndef CONFIG_COMPAT_VDSO
unsigned long __FIXADDR_TOP = 0xfffff000;
EXPORT_SYMBOL(__FIXADDR_TOP);
#endif
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);
#ifdef CONFIG_COMPAT_VDSO
BUG_ON(reserve != 0);
#else
__FIXADDR_TOP = -reserve - PAGE_SIZE;
__VMALLOC_RESERVE += reserve;
#endif
}
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.
* The locking scheme was chosen on the basis of manfred's
* recommendations and having no core impact whatsoever.
* -- 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);
}
void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
{
unsigned long flags;
if (PTRS_PER_PMD == 1) {
memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
spin_lock_irqsave(&pgd_lock, flags);
}
clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
swapper_pg_dir + USER_PTRS_PER_PGD,
KERNEL_PGD_PTRS);
if (PTRS_PER_PMD > 1)
return;
/* must happen under lock */
paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
__pa(swapper_pg_dir) >> PAGE_SHIFT,
USER_PTRS_PER_PGD, PTRS_PER_PGD - USER_PTRS_PER_PGD);
pgd_list_add(pgd);
spin_unlock_irqrestore(&pgd_lock, flags);
}
/* never called when PTRS_PER_PMD > 1 */
void pgd_dtor(void *pgd, struct kmem_cache *cache, unsigned long unused)
{
unsigned long flags; /* can be called from interrupt context */
paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
spin_lock_irqsave(&pgd_lock, flags);
pgd_list_del(pgd);
spin_unlock_irqrestore(&pgd_lock, flags);
}
pgd_t *pgd_alloc(struct mm_struct *mm)
{
int i;
pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
if (PTRS_PER_PMD == 1 || !pgd)
return pgd;
for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
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);
kmem_cache_free(pmd_cache, pmd);
}
kmem_cache_free(pgd_cache, 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 < USER_PTRS_PER_PGD; ++i) {
pgd_t pgdent = pgd[i];
void* pmd = (void *)__va(pgd_val(pgdent)-1);
paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
kmem_cache_free(pmd_cache, pmd);
}
/* in the non-PAE case, free_pgtables() clears user pgd entries */
kmem_cache_free(pgd_cache, pgd);
}
