Module kernel::dma::attrs

DMA mapping attributes.

Constants

• DMA_ATTR_ALLOC_SINGLE_PAGES
  This is a hint to the DMA-mapping subsystem that it’s probably not worth the time to try to allocate memory to in a way that gives better TLB efficiency.
• DMA_ATTR_FORCE_CONTIGUOUS
  Forces contiguous allocation of the buffer in physical memory.
• DMA_ATTR_NO_KERNEL_MAPPING
  Lets the platform to avoid creating a kernel virtual mapping for the allocated buffer.
• DMA_ATTR_NO_WARN
  This tells the DMA-mapping subsystem to suppress allocation failure reports (similarly to __GFP_NOWARN).
• DMA_ATTR_PRIVILEGED
  Used to indicate that the buffer is fully accessible at an elevated privilege level (and ideally inaccessible or at least read-only at lesser-privileged levels).
• DMA_ATTR_SKIP_CPU_SYNC
  Allows platform code to skip synchronization of the CPU cache for the given buffer assuming that it has been already transferred to ‘device’ domain.
• DMA_ATTR_WEAK_ORDERING
  Specifies that reads and writes to the mapping may be weakly ordered, that is that reads and writes may pass each other.
• DMA_ATTR_WRITE_COMBINE
  Specifies that writes to the mapping may be buffered to improve performance.