![Randy Dunlap](/assets/img/avatar_default.png)
Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
392 lines
9.2 KiB
C
392 lines
9.2 KiB
C
/*
|
|
* IA-32 Huge TLB Page Support for Kernel.
|
|
*
|
|
* Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/hugetlb.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/err.h>
|
|
#include <linux/sysctl.h>
|
|
#include <asm/mman.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
static unsigned long page_table_shareable(struct vm_area_struct *svma,
|
|
struct vm_area_struct *vma,
|
|
unsigned long addr, pgoff_t idx)
|
|
{
|
|
unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
|
|
svma->vm_start;
|
|
unsigned long sbase = saddr & PUD_MASK;
|
|
unsigned long s_end = sbase + PUD_SIZE;
|
|
|
|
/*
|
|
* match the virtual addresses, permission and the alignment of the
|
|
* page table page.
|
|
*/
|
|
if (pmd_index(addr) != pmd_index(saddr) ||
|
|
vma->vm_flags != svma->vm_flags ||
|
|
sbase < svma->vm_start || svma->vm_end < s_end)
|
|
return 0;
|
|
|
|
return saddr;
|
|
}
|
|
|
|
static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
unsigned long base = addr & PUD_MASK;
|
|
unsigned long end = base + PUD_SIZE;
|
|
|
|
/*
|
|
* check on proper vm_flags and page table alignment
|
|
*/
|
|
if (vma->vm_flags & VM_MAYSHARE &&
|
|
vma->vm_start <= base && end <= vma->vm_end)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* search for a shareable pmd page for hugetlb.
|
|
*/
|
|
static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
|
|
{
|
|
struct vm_area_struct *vma = find_vma(mm, addr);
|
|
struct address_space *mapping = vma->vm_file->f_mapping;
|
|
pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
|
|
vma->vm_pgoff;
|
|
struct prio_tree_iter iter;
|
|
struct vm_area_struct *svma;
|
|
unsigned long saddr;
|
|
pte_t *spte = NULL;
|
|
|
|
if (!vma_shareable(vma, addr))
|
|
return;
|
|
|
|
spin_lock(&mapping->i_mmap_lock);
|
|
vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) {
|
|
if (svma == vma)
|
|
continue;
|
|
|
|
saddr = page_table_shareable(svma, vma, addr, idx);
|
|
if (saddr) {
|
|
spte = huge_pte_offset(svma->vm_mm, saddr);
|
|
if (spte) {
|
|
get_page(virt_to_page(spte));
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!spte)
|
|
goto out;
|
|
|
|
spin_lock(&mm->page_table_lock);
|
|
if (pud_none(*pud))
|
|
pud_populate(mm, pud, (unsigned long) spte & PAGE_MASK);
|
|
else
|
|
put_page(virt_to_page(spte));
|
|
spin_unlock(&mm->page_table_lock);
|
|
out:
|
|
spin_unlock(&mapping->i_mmap_lock);
|
|
}
|
|
|
|
/*
|
|
* unmap huge page backed by shared pte.
|
|
*
|
|
* Hugetlb pte page is ref counted at the time of mapping. If pte is shared
|
|
* indicated by page_count > 1, unmap is achieved by clearing pud and
|
|
* decrementing the ref count. If count == 1, the pte page is not shared.
|
|
*
|
|
* called with vma->vm_mm->page_table_lock held.
|
|
*
|
|
* returns: 1 successfully unmapped a shared pte page
|
|
* 0 the underlying pte page is not shared, or it is the last user
|
|
*/
|
|
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
|
|
{
|
|
pgd_t *pgd = pgd_offset(mm, *addr);
|
|
pud_t *pud = pud_offset(pgd, *addr);
|
|
|
|
BUG_ON(page_count(virt_to_page(ptep)) == 0);
|
|
if (page_count(virt_to_page(ptep)) == 1)
|
|
return 0;
|
|
|
|
pud_clear(pud);
|
|
put_page(virt_to_page(ptep));
|
|
*addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
|
|
return 1;
|
|
}
|
|
|
|
pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pte_t *pte = NULL;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
pud = pud_alloc(mm, pgd, addr);
|
|
if (pud) {
|
|
if (pud_none(*pud))
|
|
huge_pmd_share(mm, addr, pud);
|
|
pte = (pte_t *) pmd_alloc(mm, pud, addr);
|
|
}
|
|
BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
|
|
|
|
return pte;
|
|
}
|
|
|
|
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pmd_t *pmd = NULL;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
if (pgd_present(*pgd)) {
|
|
pud = pud_offset(pgd, addr);
|
|
if (pud_present(*pud))
|
|
pmd = pmd_offset(pud, addr);
|
|
}
|
|
return (pte_t *) pmd;
|
|
}
|
|
|
|
#if 0 /* This is just for testing */
|
|
struct page *
|
|
follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
|
|
{
|
|
unsigned long start = address;
|
|
int length = 1;
|
|
int nr;
|
|
struct page *page;
|
|
struct vm_area_struct *vma;
|
|
|
|
vma = find_vma(mm, addr);
|
|
if (!vma || !is_vm_hugetlb_page(vma))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
pte = huge_pte_offset(mm, address);
|
|
|
|
/* hugetlb should be locked, and hence, prefaulted */
|
|
WARN_ON(!pte || pte_none(*pte));
|
|
|
|
page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
|
|
|
|
WARN_ON(!PageCompound(page));
|
|
|
|
return page;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
#else
|
|
|
|
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 !!(pmd_val(pmd) & _PAGE_PSE);
|
|
}
|
|
|
|
struct page *
|
|
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
|
|
pmd_t *pmd, int write)
|
|
{
|
|
struct page *page;
|
|
|
|
page = pte_page(*(pte_t *)pmd);
|
|
if (page)
|
|
page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
|
|
return page;
|
|
}
|
|
#endif
|
|
|
|
/* x86_64 also uses this file */
|
|
|
|
#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
|
|
static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
|
|
unsigned long addr, unsigned long len,
|
|
unsigned long pgoff, unsigned long flags)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma;
|
|
unsigned long start_addr;
|
|
|
|
if (len > mm->cached_hole_size) {
|
|
start_addr = mm->free_area_cache;
|
|
} else {
|
|
start_addr = TASK_UNMAPPED_BASE;
|
|
mm->cached_hole_size = 0;
|
|
}
|
|
|
|
full_search:
|
|
addr = ALIGN(start_addr, HPAGE_SIZE);
|
|
|
|
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
|
|
/* At this point: (!vma || addr < vma->vm_end). */
|
|
if (TASK_SIZE - len < addr) {
|
|
/*
|
|
* Start a new search - just in case we missed
|
|
* some holes.
|
|
*/
|
|
if (start_addr != TASK_UNMAPPED_BASE) {
|
|
start_addr = TASK_UNMAPPED_BASE;
|
|
mm->cached_hole_size = 0;
|
|
goto full_search;
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
if (!vma || addr + len <= vma->vm_start) {
|
|
mm->free_area_cache = addr + len;
|
|
return addr;
|
|
}
|
|
if (addr + mm->cached_hole_size < vma->vm_start)
|
|
mm->cached_hole_size = vma->vm_start - addr;
|
|
addr = ALIGN(vma->vm_end, HPAGE_SIZE);
|
|
}
|
|
}
|
|
|
|
static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
|
|
unsigned long addr0, unsigned long len,
|
|
unsigned long pgoff, unsigned long flags)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma, *prev_vma;
|
|
unsigned long base = mm->mmap_base, addr = addr0;
|
|
unsigned long largest_hole = mm->cached_hole_size;
|
|
int first_time = 1;
|
|
|
|
/* don't allow allocations above current base */
|
|
if (mm->free_area_cache > base)
|
|
mm->free_area_cache = base;
|
|
|
|
if (len <= largest_hole) {
|
|
largest_hole = 0;
|
|
mm->free_area_cache = base;
|
|
}
|
|
try_again:
|
|
/* make sure it can fit in the remaining address space */
|
|
if (mm->free_area_cache < len)
|
|
goto fail;
|
|
|
|
/* either no address requested or cant fit in requested address hole */
|
|
addr = (mm->free_area_cache - len) & HPAGE_MASK;
|
|
do {
|
|
/*
|
|
* Lookup failure means no vma is above this address,
|
|
* i.e. return with success:
|
|
*/
|
|
if (!(vma = find_vma_prev(mm, addr, &prev_vma)))
|
|
return addr;
|
|
|
|
/*
|
|
* new region fits between prev_vma->vm_end and
|
|
* vma->vm_start, use it:
|
|
*/
|
|
if (addr + len <= vma->vm_start &&
|
|
(!prev_vma || (addr >= prev_vma->vm_end))) {
|
|
/* remember the address as a hint for next time */
|
|
mm->cached_hole_size = largest_hole;
|
|
return (mm->free_area_cache = addr);
|
|
} else {
|
|
/* pull free_area_cache down to the first hole */
|
|
if (mm->free_area_cache == vma->vm_end) {
|
|
mm->free_area_cache = vma->vm_start;
|
|
mm->cached_hole_size = largest_hole;
|
|
}
|
|
}
|
|
|
|
/* remember the largest hole we saw so far */
|
|
if (addr + largest_hole < vma->vm_start)
|
|
largest_hole = vma->vm_start - addr;
|
|
|
|
/* try just below the current vma->vm_start */
|
|
addr = (vma->vm_start - len) & HPAGE_MASK;
|
|
} while (len <= vma->vm_start);
|
|
|
|
fail:
|
|
/*
|
|
* if hint left us with no space for the requested
|
|
* mapping then try again:
|
|
*/
|
|
if (first_time) {
|
|
mm->free_area_cache = base;
|
|
largest_hole = 0;
|
|
first_time = 0;
|
|
goto try_again;
|
|
}
|
|
/*
|
|
* A failed mmap() very likely causes application failure,
|
|
* so fall back to the bottom-up function here. This scenario
|
|
* can happen with large stack limits and large mmap()
|
|
* allocations.
|
|
*/
|
|
mm->free_area_cache = TASK_UNMAPPED_BASE;
|
|
mm->cached_hole_size = ~0UL;
|
|
addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
|
|
len, pgoff, flags);
|
|
|
|
/*
|
|
* Restore the topdown base:
|
|
*/
|
|
mm->free_area_cache = base;
|
|
mm->cached_hole_size = ~0UL;
|
|
|
|
return addr;
|
|
}
|
|
|
|
unsigned long
|
|
hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
|
|
unsigned long len, unsigned long pgoff, unsigned long flags)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma;
|
|
|
|
if (len & ~HPAGE_MASK)
|
|
return -EINVAL;
|
|
if (len > TASK_SIZE)
|
|
return -ENOMEM;
|
|
|
|
if (flags & MAP_FIXED) {
|
|
if (prepare_hugepage_range(addr, len, pgoff))
|
|
return -EINVAL;
|
|
return addr;
|
|
}
|
|
|
|
if (addr) {
|
|
addr = ALIGN(addr, HPAGE_SIZE);
|
|
vma = find_vma(mm, addr);
|
|
if (TASK_SIZE - len >= addr &&
|
|
(!vma || addr + len <= vma->vm_start))
|
|
return addr;
|
|
}
|
|
if (mm->get_unmapped_area == arch_get_unmapped_area)
|
|
return hugetlb_get_unmapped_area_bottomup(file, addr, len,
|
|
pgoff, flags);
|
|
else
|
|
return hugetlb_get_unmapped_area_topdown(file, addr, len,
|
|
pgoff, flags);
|
|
}
|
|
|
|
#endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/
|
|
|