Re: [PATCH v24 11/11] sfc: support pio mapping based on cxl

Edward Cree
2026-03-23T22:18:08Z

On 23/03/2026 11:31, alejandro.lucero-palau@amd.com wrote:
> From: Alejandro Lucero <alucerop@amd.com>
>
> A PIO buffer is a region of device memory to which the driver can write a
> packet for TX, with the device handling the transmit doorbell without
> requiring a DMA for getting the packet data, which helps reducing latency
> in certain exchanges. With CXL mem protocol this latency can be lowered
> further.
>
> With a device supporting CXL and successfully initialised, use the cxl
> region to map the memory range and use this mapping for PIO buffers.
>
> Add the disabling of those CXL-based PIO buffers if the callback for
> potential cxl endpoint removal by the CXL code happens.
>
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>

Acked-by: Edward Cree <ecree.xilinx@gmail.com>