static void __dma_free_remap(void *cpu_addr, size_t size)
{
struct arm_vmregion *c;
unsigned long addr;
pte_t *ptep;
int idx;
u32 off;
c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr);
if (!c) {
printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
__func__, cpu_addr);
dump_stack();
return;
}
if ((c->vm_end - c->vm_start) != size) {
printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
__func__, c->vm_end - c->vm_start, size);
dump_stack();
size = c->vm_end - c->vm_start;
}
idx = CONSISTENT_PTE_INDEX(c->vm_start);
off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
ptep = consistent_pte[idx] + off;
addr = c->vm_start;
do {
pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
ptep++;
addr += PAGE_SIZE;
off++;
if (off >= PTRS_PER_PTE) {
off = 0;
ptep = consistent_pte[++idx];
}
if (pte_none(pte) || !pte_present(pte))
printk(KERN_CRIT "%s: bad page in kernel page table\n",
__func__);
} while (size -= PAGE_SIZE);
flush_tlb_kernel_range(c->vm_start, c->vm_end);
arm_vmregion_free(&consistent_head, c);
}
static inline void zeromap_pte_range(pte_t * pte, unsigned long address,
unsigned long size, pgprot_t prot)
{
unsigned long end;
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
do {
pte_t zero_pte = pte_wrprotect(mk_pte(ZERO_PAGE(address), prot));
pte_t oldpage = ptep_get_and_clear(pte);
set_pte(pte, zero_pte);
forget_pte(oldpage);
address += PAGE_SIZE;
pte++;
} while (address && (address < end));
}
static inline void zeromap_pte_range(struct mm_struct *mm, pte_t * pte,
unsigned long address, unsigned long size,
pgprot_t prot)
{
unsigned long end;
debug_lock_break(1);
break_spin_lock(&mm->page_table_lock);
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
do {
pte_t zero_pte = pte_wrprotect(mk_pte(ZERO_PAGE(address), prot));
pte_t oldpage = ptep_get_and_clear(pte);
set_pte(pte, zero_pte);
forget_pte(oldpage);
address += PAGE_SIZE;
pte++;
} while (address && (address < end));
}
/*
* maps a range of physical memory into the requested pages. the old
* mappings are removed. any references to nonexistent pages results
* in null mappings (currently treated as "copy-on-access")
*/
static inline void remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
unsigned long phys_addr, pgprot_t prot)
{
unsigned long end;
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
do {
struct page *page;
pte_t oldpage;
oldpage = ptep_get_and_clear(pte);
page = virt_to_page(__va(phys_addr));
if ((!VALID_PAGE(page)) || PageReserved(page))
set_pte(pte, mk_pte_phys(phys_addr, prot));
forget_pte(oldpage);
address += PAGE_SIZE;
phys_addr += PAGE_SIZE;
pte++;
} while (address && (address < end));
}
/* mm->page_table_lock is held. mmap_sem is not held */
static inline int try_to_swap_out(struct mm_struct * mm, struct vm_area_struct* vma, unsigned long address, pte_t * page_table, struct page *page, zone_t * classzone)
{
pte_t pte;
swp_entry_t entry;
/* Don't look at this pte if it's been accessed recently. */
if ((vma->vm_flags & VM_LOCKED) || ptep_test_and_clear_young(page_table)) {
mark_page_accessed(page);
return 0;
}
/* Don't bother unmapping pages that are active */
if (PageActive(page))
return 0;
/* Don't bother replenishing zones not under pressure.. */
if (!memclass(page->zone, classzone))
return 0;
if (TryLockPage(page))
return 0;
/* From this point on, the odds are that we're going to
* nuke this pte, so read and clear the pte. This hook
* is needed on CPUs which update the accessed and dirty
* bits in hardware.
*/
flush_cache_page(vma, address);
pte = ptep_get_and_clear(page_table);
flush_tlb_page(vma, address);
if (pte_dirty(pte))
set_page_dirty(page);
/*
* Is the page already in the swap cache? If so, then
* we can just drop our reference to it without doing
* any IO - it's already up-to-date on disk.
*/
if (PageSwapCache(page)) {
entry.val = page->index;
swap_duplicate(entry);
set_swap_pte:
set_pte(page_table, swp_entry_to_pte(entry));
drop_pte:
mm->rss--;
UnlockPage(page);
{
int freeable = page_count(page) - !!page->buffers <= 2;
page_cache_release(page);
return freeable;
}
}
/*
* Is it a clean page? Then it must be recoverable
* by just paging it in again, and we can just drop
* it.. or if it's dirty but has backing store,
* just mark the page dirty and drop it.
*
* However, this won't actually free any real
* memory, as the page will just be in the page cache
* somewhere, and as such we should just continue
* our scan.
*
* Basically, this just makes it possible for us to do
* some real work in the future in "refill_inactive()".
*/
if (page->mapping)
goto drop_pte;
if (!PageDirty(page))
goto drop_pte;
/*
* Anonymous buffercache pages can be left behind by
* concurrent truncate and pagefault.
*/
if (page->buffers)
goto preserve;
/*
* This is a dirty, swappable page. First of all,
* get a suitable swap entry for it, and make sure
* we have the swap cache set up to associate the
* page with that swap entry.
*/
for (;;) {
entry = get_swap_page();
if (!entry.val)
break;
/* Add it to the swap cache and mark it dirty
* (adding to the page cache will clear the dirty
* and uptodate bits, so we need to do it again)
*/
if (add_to_swap_cache(page, entry) == 0) {
SetPageUptodate(page);
set_page_dirty(page);
goto set_swap_pte;
}
/* Raced with "speculative" read_swap_cache_async */
swap_free(entry);
}
/* No swap space left */
preserve:
set_pte(page_table, pte);
UnlockPage(page);
return 0;
}
/*
* The swap-out functions return 1 if they successfully
* threw something out, and we got a free page. It returns
* zero if it couldn't do anything, and any other value
* indicates it decreased rss, but the page was shared.
*
* NOTE! If it sleeps, it *must* return 1 to make sure we
* don't continue with the swap-out. Otherwise we may be
* using a process that no longer actually exists (it might
* have died while we slept).
*/
static int try_to_swap_out(struct mm_struct * mm, struct vm_area_struct* vma, unsigned long address, pte_t * page_table, int gfp_mask)
{
pte_t pte;
swp_entry_t entry;
struct page * page;
int onlist;
pte = *page_table;
if (!pte_present(pte))
goto out_failed;
page = pte_page(pte);
if ((!VALID_PAGE(page)) || PageReserved(page))
goto out_failed;
if (mm->swap_cnt)
mm->swap_cnt--;
onlist = PageActive(page);
/* Don't look at this pte if it's been accessed recently. */
if (ptep_test_and_clear_young(page_table)) {
age_page_up(page);
goto out_failed;
}
if (!onlist)
/* The page is still mapped, so it can't be freeable... */
age_page_down_ageonly(page);
/*
* If the page is in active use by us, or if the page
* is in active use by others, don't unmap it or
* (worse) start unneeded IO.
*/
if (page->age > 0)
goto out_failed;
if (TryLockPage(page))
goto out_failed;
/* From this point on, the odds are that we're going to
* nuke this pte, so read and clear the pte. This hook
* is needed on CPUs which update the accessed and dirty
* bits in hardware.
*/
pte = ptep_get_and_clear(page_table);
/*
* Is the page already in the swap cache? If so, then
* we can just drop our reference to it without doing
* any IO - it's already up-to-date on disk.
*
* Return 0, as we didn't actually free any real
* memory, and we should just continue our scan.
*/
if (PageSwapCache(page)) {
entry.val = page->index;
if (pte_dirty(pte))
set_page_dirty(page);
set_swap_pte:
swap_duplicate(entry);
set_pte(page_table, swp_entry_to_pte(entry));
drop_pte:
UnlockPage(page);
mm->rss--;
flush_tlb_page(vma, address);
deactivate_page(page);
page_cache_release(page);
out_failed:
return 0;
}
/*
* Is it a clean page? Then it must be recoverable
* by just paging it in again, and we can just drop
* it..
*
* However, this won't actually free any real
* memory, as the page will just be in the page cache
* somewhere, and as such we should just continue
* our scan.
*
* Basically, this just makes it possible for us to do
* some real work in the future in "refill_inactive()".
*/
flush_cache_page(vma, address);
if (!pte_dirty(pte))
goto drop_pte;
/*
* Ok, it's really dirty. That means that
* we should either create a new swap cache
* entry for it, or we should write it back
* to its own backing store.
*/
if (page->mapping) {
set_page_dirty(page);
goto drop_pte;
}
/*
* This is a dirty, swappable page. First of all,
* get a suitable swap entry for it, and make sure
* we have the swap cache set up to associate the
* page with that swap entry.
*/
entry = get_swap_page();
if (!entry.val)
goto out_unlock_restore; /* No swap space left */
/* Add it to the swap cache and mark it dirty */
add_to_swap_cache(page, entry);
set_page_dirty(page);
goto set_swap_pte;
out_unlock_restore:
set_pte(page_table, pte);
UnlockPage(page);
return 0;
}
