px_used
idx, len, atomic_read(px_used(pd)));
GEM_BUG_ON(!len || len >= atomic_read(px_used(pd)));
idx, len, atomic_read(px_used(pd)));
GEM_BUG_ON(!atomic_read(px_used(pd))); /* Must be pinned! */
atomic_inc(px_used(pde)); /* keep pinned */
atomic_inc(px_used(pd)); /* mark as pinned */
atomic_inc(px_used(ppgtt->pd)); /* never remove */
atomic_dec(px_used(ppgtt->pd));
GEM_BUG_ON(atomic_read(px_used(pd)) > NALLOC * I915_PDES);
atomic_inc(px_used(pd));
GEM_BUG_ON(atomic_read(px_used(pd)) == 0);
atomic_dec(px_used(pd));