drivers/built-in.o: In function `nvme_nvm_dev_dma_free':
lightnvm.c:(.text+0x23df1a): undefined reference to `dma_pool_free'
drivers/built-in.o: In function `nvme_nvm_dev_dma_alloc':
lightnvm.c:(.text+0x23df38): undefined reference to `dma_pool_alloc'
drivers/built-in.o: In function `nvme_nvm_destroy_dma_pool':
lightnvm.c:(.text+0x23df4c): undefined reference to `dma_pool_destroy'
drivers/built-in.o: In function `nvme_nvm_create_dma_pool':
lightnvm.c:(.text+0x23df7e): undefined reference to `dma_pool_create'