swh:1:snp:77163734605b0ec556b01d897b7bb4a7e30d46b6
Tip revision: 9fe6206f400646a2322096b56c59891d530e8d51 authored by Linus Torvalds on 01 August 2010, 22:11:14 UTC
Linux 2.6.35
Linux 2.6.35
Tip revision: 9fe6206
hugetlbpage.c
/*
* IA-64 Huge TLB Page Support for Kernel.
*
* Copyright (C) 2002-2004 Rohit Seth <rohit.seth@intel.com>
* Copyright (C) 2003-2004 Ken Chen <kenneth.w.chen@intel.com>
*
* Sep, 2003: add numa support
* Feb, 2004: dynamic hugetlb page size via boot parameter
*/
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <linux/log2.h>
#include <asm/mman.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
unsigned int hpage_shift = HPAGE_SHIFT_DEFAULT;
EXPORT_SYMBOL(hpage_shift);
pte_t *
huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
{
unsigned long taddr = htlbpage_to_page(addr);
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, taddr);
pud = pud_alloc(mm, pgd, taddr);
if (pud) {
pmd = pmd_alloc(mm, pud, taddr);
if (pmd)
pte = pte_alloc_map(mm, pmd, taddr);
}
return pte;
}
pte_t *
huge_pte_offset (struct mm_struct *mm, unsigned long addr)
{
unsigned long taddr = htlbpage_to_page(addr);
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, taddr);
if (pgd_present(*pgd)) {
pud = pud_offset(pgd, taddr);
if (pud_present(*pud)) {
pmd = pmd_offset(pud, taddr);
if (pmd_present(*pmd))
pte = pte_offset_map(pmd, taddr);
}
}
return pte;
}
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
return 0;
}
#define mk_pte_huge(entry) { pte_val(entry) |= _PAGE_P; }
/*
* Don't actually need to do any preparation, but need to make sure
* the address is in the right region.
*/
int prepare_hugepage_range(struct file *file,
unsigned long addr, unsigned long len)
{
if (len & ~HPAGE_MASK)
return -EINVAL;
if (addr & ~HPAGE_MASK)
return -EINVAL;
if (REGION_NUMBER(addr) != RGN_HPAGE)
return -EINVAL;
return 0;
}
struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write)
{
struct page *page;
pte_t *ptep;
if (REGION_NUMBER(addr) != RGN_HPAGE)
return ERR_PTR(-EINVAL);
ptep = huge_pte_offset(mm, addr);
if (!ptep || pte_none(*ptep))
return NULL;
page = pte_page(*ptep);
page += ((addr & ~HPAGE_MASK) >> PAGE_SHIFT);
return page;
}
int pmd_huge(pmd_t pmd)
{
return 0;
}
int pud_huge(pud_t pud)
{
return 0;
}
struct page *
follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
{
return NULL;
}
void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
/*
* This is called to free hugetlb page tables.
*
* The offset of these addresses from the base of the hugetlb
* region must be scaled down by HPAGE_SIZE/PAGE_SIZE so that
* the standard free_pgd_range will free the right page tables.
*
* If floor and ceiling are also in the hugetlb region, they
* must likewise be scaled down; but if outside, left unchanged.
*/
addr = htlbpage_to_page(addr);
end = htlbpage_to_page(end);
if (REGION_NUMBER(floor) == RGN_HPAGE)
floor = htlbpage_to_page(floor);
if (REGION_NUMBER(ceiling) == RGN_HPAGE)
ceiling = htlbpage_to_page(ceiling);
free_pgd_range(tlb, addr, end, floor, ceiling);
}
unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
struct vm_area_struct *vmm;
if (len > RGN_MAP_LIMIT)
return -ENOMEM;
if (len & ~HPAGE_MASK)
return -EINVAL;
/* Handle MAP_FIXED */
if (flags & MAP_FIXED) {
if (prepare_hugepage_range(file, addr, len))
return -EINVAL;
return addr;
}
/* This code assumes that RGN_HPAGE != 0. */
if ((REGION_NUMBER(addr) != RGN_HPAGE) || (addr & (HPAGE_SIZE - 1)))
addr = HPAGE_REGION_BASE;
else
addr = ALIGN(addr, HPAGE_SIZE);
for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
/* At this point: (!vmm || addr < vmm->vm_end). */
if (REGION_OFFSET(addr) + len > RGN_MAP_LIMIT)
return -ENOMEM;
if (!vmm || (addr + len) <= vmm->vm_start)
return addr;
addr = ALIGN(vmm->vm_end, HPAGE_SIZE);
}
}
static int __init hugetlb_setup_sz(char *str)
{
u64 tr_pages;
unsigned long long size;
if (ia64_pal_vm_page_size(&tr_pages, NULL) != 0)
/*
* shouldn't happen, but just in case.
*/
tr_pages = 0x15557000UL;
size = memparse(str, &str);
if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
size <= PAGE_SIZE ||
size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
printk(KERN_WARNING "Invalid huge page size specified\n");
return 1;
}
hpage_shift = __ffs(size);
/*
* boot cpu already executed ia64_mmu_init, and has HPAGE_SHIFT_DEFAULT
* override here with new page shift.
*/
ia64_set_rr(HPAGE_REGION_BASE, hpage_shift << 2);
return 0;
}
early_param("hugepagesz", hugetlb_setup_sz);