Name

dma_buf_begin_cpu_access — Must be called before accessing a dma_buf from the cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific preparations. Coherency is only guaranteed in the specified range for the specified access direction.

Synopsis

int dma_buf_begin_cpu_access (struct dma_buf * dmabuf,
 enum dma_data_direction direction);
 

Arguments

dmabuf

[in] buffer to prepare cpu access for.

direction

[in] length of range for cpu access.

Description

After the cpu access is complete the caller should call dma_buf_end_cpu_access. Only when cpu access is braketed by both calls is it guaranteed to be coherent with other DMA access.

Can return negative error values, returns 0 on success.