> +int ttm_dma_populate(struct ttm_tt *ttm, struct device *dev)
> +{
.. snip..
> + for (i = 0; i < ttm->num_pages; ++i) {
> + ret = ttm_dma_pool_get_pages(pool, ttm, i);
> + if (ret != 0) {
> + ttm_dma_unpopulate(ttm, dev);
> + return -ENOMEM;
> + }
> +
> + ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
> + false, false);
Ok, so we increment it here..
.. snip..
> +void ttm_dma_unpopulate(struct ttm_tt *ttm, struct device *dev)
> +{
> + struct dma_pool *pool;
> + struct dma_page *d_page;
> + enum pool_type type;
> + bool is_cached = false;
> + unsigned count = 0, i;
> + unsigned long irq_flags;
> +
> + type = ttm_to_type(ttm->page_flags, ttm->caching_state);
> + pool = ttm_dma_find_pool(dev, type);
> + if (!pool) {
> + WARN_ON(!pool);
> + return;
> + }
> + is_cached = (ttm_dma_find_pool(pool->dev,
> + ttm_to_type(ttm->page_flags, tt_cached)) == pool);
> +
> + /* make sure pages array match list and count number of pages */
> + list_for_each_entry(d_page, &ttm->alloc_list, page_list) {
> + ttm->pages[count] = d_page->p;
> + count++;
> + }
> +
> + spin_lock_irqsave(&pool->lock, irq_flags);
> + pool->npages_in_use -= count;
> + if (is_cached) {
> + pool->nfrees += count;
> + } else {
> + pool->npages_free += count;
> + list_splice(&ttm->alloc_list, &pool->free_list);
> + if (pool->npages_free > _manager->options.max_size) {
> + count = pool->npages_free - _manager->options.max_size;
> + }
> + }
> + spin_unlock_irqrestore(&pool->lock, irq_flags);
But we don't do it here. I think you need:
for (i = 0; i < ttm->num_pages; i++) {
ttm_mem_global_free_page(mem_glob, ttm->pages[i]);
And it has to be done before ttm_dma_pages_put as at that point the
pages are truly gone.
Could actually be done in the '/* make sure pages array match list .."
> +
> + if (is_cached) {
> + ttm_dma_pages_put(pool, &ttm->alloc_list,
> + ttm->pages, count);
> + }
> +
> + INIT_LIST_HEAD(&ttm->alloc_list);
> + for (i = 0; i < ttm->num_pages; i++) {
> + ttm->pages[i] = NULL;
> + ttm->dma_address[i] = 0;
> + }
