linux/arch/sh/mm/hugetlbpage.c

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/*
* arch/sh/mm/hugetlbpage.c
*
* SuperH HugeTLB page support.
*
* Cloned from sparc64 by Paul Mundt.
*
* Copyright (C) 2002, 2003 David S. Miller (davem@redhat.com)
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <asm/mman.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
static pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, addr);
if (pgd) {
pmd = pmd_alloc(mm, pgd, addr);
if (pmd)
pte = pte_alloc_map(mm, pmd, addr);
}
return pte;
}
static pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, addr);
if (pgd) {
pmd = pmd_offset(pgd, addr);
if (pmd)
pte = pte_offset_map(pmd, addr);
}
return pte;
}
#define mk_pte_huge(entry) do { pte_val(entry) |= _PAGE_SZHUGE; } while (0)
static void set_huge_pte(struct mm_struct *mm, struct vm_area_struct *vma,
struct page *page, pte_t * page_table, int write_access)
{
unsigned long i;
pte_t entry;
add_mm_counter(mm, rss, HPAGE_SIZE / PAGE_SIZE);
if (write_access)
entry = pte_mkwrite(pte_mkdirty(mk_pte(page,
vma->vm_page_prot)));
else
entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
entry = pte_mkyoung(entry);
mk_pte_huge(entry);
for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
set_pte(page_table, entry);
page_table++;
pte_val(entry) += PAGE_SIZE;
}
}
/*
* This function checks for proper alignment of input addr and len parameters.
*/
int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
{
if (len & ~HPAGE_MASK)
return -EINVAL;
if (addr & ~HPAGE_MASK)
return -EINVAL;
return 0;
}
int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
struct vm_area_struct *vma)
{
pte_t *src_pte, *dst_pte, entry;
struct page *ptepage;
unsigned long addr = vma->vm_start;
unsigned long end = vma->vm_end;
int i;
while (addr < end) {
dst_pte = huge_pte_alloc(dst, addr);
if (!dst_pte)
goto nomem;
src_pte = huge_pte_offset(src, addr);
BUG_ON(!src_pte || pte_none(*src_pte));
entry = *src_pte;
ptepage = pte_page(entry);
get_page(ptepage);
for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
set_pte(dst_pte, entry);
pte_val(entry) += PAGE_SIZE;
dst_pte++;
}
add_mm_counter(dst, rss, HPAGE_SIZE / PAGE_SIZE);
addr += HPAGE_SIZE;
}
return 0;
nomem:
return -ENOMEM;
}
int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
struct page **pages, struct vm_area_struct **vmas,
unsigned long *position, int *length, int i)
{
unsigned long vaddr = *position;
int remainder = *length;
WARN_ON(!is_vm_hugetlb_page(vma));
while (vaddr < vma->vm_end && remainder) {
if (pages) {
pte_t *pte;
struct page *page;
pte = huge_pte_offset(mm, vaddr);
/* hugetlb should be locked, and hence, prefaulted */
BUG_ON(!pte || pte_none(*pte));
page = pte_page(*pte);
WARN_ON(!PageCompound(page));
get_page(page);
pages[i] = page;
}
if (vmas)
vmas[i] = vma;
vaddr += PAGE_SIZE;
--remainder;
++i;
}
*length = remainder;
*position = vaddr;
return i;
}
struct page *follow_huge_addr(struct mm_struct *mm,
unsigned long address, int write)
{
return ERR_PTR(-EINVAL);
}
int pmd_huge(pmd_t pmd)
{
return 0;
}
struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
pmd_t *pmd, int write)
{
return NULL;
}
void unmap_hugepage_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long address;
pte_t *pte;
struct page *page;
int i;
BUG_ON(start & (HPAGE_SIZE - 1));
BUG_ON(end & (HPAGE_SIZE - 1));
for (address = start; address < end; address += HPAGE_SIZE) {
pte = huge_pte_offset(mm, address);
BUG_ON(!pte);
if (pte_none(*pte))
continue;
page = pte_page(*pte);
put_page(page);
for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
pte_clear(mm, address+(i*PAGE_SIZE), pte);
pte++;
}
}
add_mm_counter(mm, rss, -((end - start) >> PAGE_SHIFT));
flush_tlb_range(vma, start, end);
}
int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
{
struct mm_struct *mm = current->mm;
unsigned long addr;
int ret = 0;
BUG_ON(vma->vm_start & ~HPAGE_MASK);
BUG_ON(vma->vm_end & ~HPAGE_MASK);
spin_lock(&mm->page_table_lock);
for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
unsigned long idx;
pte_t *pte = huge_pte_alloc(mm, addr);
struct page *page;
if (!pte) {
ret = -ENOMEM;
goto out;
}
if (!pte_none(*pte))
continue;
idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
+ (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
page = find_get_page(mapping, idx);
if (!page) {
/* charge the fs quota first */
if (hugetlb_get_quota(mapping)) {
ret = -ENOMEM;
goto out;
}
page = alloc_huge_page();
if (!page) {
hugetlb_put_quota(mapping);
ret = -ENOMEM;
goto out;
}
ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC);
if (! ret) {
unlock_page(page);
} else {
hugetlb_put_quota(mapping);
free_huge_page(page);
goto out;
}
}
set_huge_pte(mm, vma, page, pte, vma->vm_flags & VM_WRITE);
}
out:
spin_unlock(&mm->page_table_lock);
return ret;
}