int ttm_tt_populate(struct ttm_tt *ttm)
{
struct page *page;
unsigned long i;
struct ttm_backend *be;
int ret;
if (ttm->state != tt_unpopulated)
return 0;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
if (unlikely(ret != 0))
return ret;
}
be = ttm->be;
for (i = 0; i < ttm->num_pages; ++i) {
page = __ttm_tt_get_page(ttm, i);
if (!page)
return -ENOMEM;
}
be->func->populate(be, ttm->num_pages, ttm->pages,
ttm->dummy_read_page);
ttm->state = tt_unbound;
return 0;
}
static int ttm_tt_swapin(struct ttm_tt *ttm)
{
struct address_space *swap_space;
struct file *swap_storage;
struct page *from_page;
struct page *to_page;
void *from_virtual;
void *to_virtual;
int i;
int ret = -ENOMEM;
if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
ttm->num_pages);
if (unlikely(ret != 0))
return ret;
ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
return 0;
}
swap_storage = ttm->swap_storage;
BUG_ON(swap_storage == NULL);
swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
for (i = 0; i < ttm->num_pages; ++i) {
from_page = read_mapping_page(swap_space, i, NULL);
if (IS_ERR(from_page)) {
ret = PTR_ERR(from_page);
goto out_err;
}
to_page = __ttm_tt_get_page(ttm, i);
if (unlikely(to_page == NULL))
goto out_err;
preempt_disable();
from_virtual = kmap_atomic(from_page, KM_USER0);
to_virtual = kmap_atomic(to_page, KM_USER1);
memcpy(to_virtual, from_virtual, PAGE_SIZE);
kunmap_atomic(to_virtual, KM_USER1);
kunmap_atomic(from_virtual, KM_USER0);
preempt_enable();
page_cache_release(from_page);
}
if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
fput(swap_storage);
ttm->swap_storage = NULL;
ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
return 0;
out_err:
ttm_tt_free_alloced_pages(ttm);
return ret;
}
struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
{
int ret;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
if (unlikely(ret != 0))
return NULL;
}
return __ttm_tt_get_page(ttm, index);
}