CONFIG_DMA_SHARED_BUFFER (not configurable)

configname: CONFIG_DMA_SHARED_BUFFER

Linux Kernel Configuration
└─>Device Drivers
└─>Generic Driver Options
└─>DMA_SHARED_BUFFER
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This option enables the framework for buffer-sharing between
multiple drivers. A buffer is associated with a file using driver
APIs extension; the file's descriptor can then be passed on to other
driver.

selects
CONFIG_IRQ_WORK