linux-arm.git - Russell King's ARM Linux kernel tree

Age	Commit message (Collapse)	Author
2020-01-21	dmaengine: ti: k3-udma: Add glue layer for non DMAengine users	Grygorii Strashko
	Certain users can not use right now the DMAengine API due to missing features in the core. Prime example is Networking. These users can use the glue layer interface to avoid misuse of DMAengine API and when the core gains the needed features they can be converted to use generic API. The most prominent features the glue layer clients are depending on: - most PSI-L native peripheral use extra rflow ranges on a receive channel and depending on the peripheral's configuration packets from a single free descriptor ring is going to be received to different receive ring - it is also possible to have different free descriptor rings per rflow and an rflow can also support 4 additional free descriptor ring based on the size of the incoming packet - out of order completion of descriptors on a channel - when we have several queues to handle different priority packets the descriptors will be completed 'out-of-order' - the notion of prep_slave_sg is not matching with what the streaming type of operation is demanding for networking - Streaming type of operation - Ability to fill the free descriptor ring with descriptors in anticipation of incoming traffic and when a packet arrives UDMAP will form a packet and gives it to the client driver - the descriptors are not backed with exact size data buffers as we don't know the size of the packet we will receive, but as a generic pool of buffers to be used by the receive channel - NAPI type of operation (polling instead of interrupt driven transfer) - without this we can not sustain gigabit speeds and we need to support NAPI - not to limit this to networking, but other high performance operations Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Tested-by: Keerthy <j-keerthy@ti.com> Link: https://lore.kernel.org/r/20191223110458.30766-12-peter.ujfalusi@ti.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-01-21	dmaengine: ti: New driver for K3 UDMA	Peter Ujfalusi
	Split patch for review containing: defines, structs, io and low level functions and interrupt callbacks. DMA driver for Texas Instruments K3 NAVSS Unified DMA – Peripheral Root Complex (UDMA-P) The UDMA-P is intended to perform similar (but significantly upgraded) functions as the packet-oriented DMA used on previous SoC devices. The UDMA-P module supports the transmission and reception of various packet types. The UDMA-P is architected to facilitate the segmentation and reassembly of SoC DMA data structure compliant packets to/from smaller data blocks that are natively compatible with the specific requirements of each connected peripheral. Multiple Tx and Rx channels are provided within the DMA which allow multiple segmentation or reassembly operations to be ongoing. The DMA controller maintains state information for each of the channels which allows packet segmentation and reassembly operations to be time division multiplexed between channels in order to share the underlying DMA hardware. An external DMA scheduler is used to control the ordering and rate at which this multiplexing occurs for Transmit operations. The ordering and rate of Receive operations is indirectly controlled by the order in which blocks are pushed into the DMA on the Rx PSI-L interface. The UDMA-P also supports acting as both a UTC and UDMA-C for its internal channels. Channels in the UDMA-P can be configured to be either Packet-Based or Third-Party channels on a channel by channel basis. The initial driver supports: - MEM_TO_MEM (TR mode) - DEV_TO_MEM (Packet / TR mode) - MEM_TO_DEV (Packet / TR mode) - Cyclic (Packet / TR mode) - Metadata for descriptors Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Tested-by: Keerthy <j-keerthy@ti.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Link: https://lore.kernel.org/r/20191223110458.30766-11-peter.ujfalusi@ti.com Signed-off-by: Vinod Koul <vkoul@kernel.org>