Commits
Wesley Sheng committed f7eb7b8a4f7
switchtec: Add MRPC DMA mode support MRPC normal mode requires the host to read the MRPC command status and output data from BAR. This results in high latency responses from the Memory Read TLP and potential Completion Timeout (CTO). Add support for MRPC DMA mode, including related macro definitions and data structures and code to: * Retrieve MRPC DMA mode version from adapter firmware * Allocate DMA buffer, register ISR, and enable DMA during init * Check MRPC execution status and get execution results from DMA buffer * Release DMA buffer and disable DMA function when unloading module MRPC DMA mode is a new feature of firmware, and the driver will fall back to MRPC normal mode if there is no support in the legacy firmware. Add a module parameter, "use_dma_mrpc", to select between MRPC DMA mode and MRPC normal mode. Since the driver automatically detects DMA support in the firmware, this parameter is just for debugging and testing. Include <linux/io-64-nonatomic-lo-hi.h> so that readq/writeq is replaced by two readl/writel on systems that do not support it. Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com> [bhelgaas: changelog, simplify dma_ver check] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>