/**
* Initialize the AGP resources.
*
* \return pointer to a drm_agp_head structure.
*
*/
drm_agp_head_t *drm_agp_init(drm_device_t *dev)
{
drm_agp_head_t *head = NULL;
if (!(head = drm_alloc(sizeof(*head), DRM_MEM_AGPLISTS)))
return NULL;
memset((void *)head, 0, sizeof(*head));
head->bridge = agp_find_bridge(dev->pdev);
if (!head->bridge) {
if (!(head->bridge = agp_backend_acquire(dev->pdev))) {
drm_free(head, sizeof(*head), DRM_MEM_AGPLISTS);
return NULL;
}
agp_copy_info(head->bridge, &head->agp_info);
agp_backend_release(head->bridge);
} else {
agp_copy_info(head->bridge, &head->agp_info);
}
if (head->agp_info.chipset == NOT_SUPPORTED) {
drm_free(head, sizeof(*head), DRM_MEM_AGPLISTS);
return NULL;
}
head->memory = NULL;
head->cant_use_aperture = head->agp_info.cant_use_aperture;
head->page_mask = head->agp_info.page_mask;
return head;
}
struct agp_bridge_data *agp_backend_acquire(struct pci_dev *pdev)
{
struct agp_bridge_data *bridge;
bridge = agp_find_bridge(pdev);
if (!bridge)
return NULL;
if (atomic_read(&bridge->agp_in_use))
return NULL;
atomic_inc(&bridge->agp_in_use);
return bridge;
}
