drm_pci_alloc
extern drm_dma_handle_t *drm_pci_alloc(struct drm_device *dev, size_t size,
dmah = drm_pci_alloc(dev, map->size, align, BUS_SPACE_MAXADDR);
dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000, BUS_SPACE_MAXADDR);
EXPORT_SYMBOL(drm_pci_alloc);