INDIRECT_CTX_RING_HEAD
xe_lrc_write_indirect_ctx_reg(lrc, INDIRECT_CTX_RING_HEAD, 0);
xe_lrc_write_indirect_ctx_reg(lrc, INDIRECT_CTX_RING_HEAD, head);
return xe_lrc_read_indirect_ctx_reg(lrc, INDIRECT_CTX_RING_HEAD) & HEAD_ADDR;