On Tue, Jun 12, 2018 at 5:10 AM, Wu Hao [off-list ref] wrote:

Device Feature List (DFL) defines a feature list structure that creates
a link list of feature headers within the MMIO space to provide an
extensible way of adding features. This patch introduces a kernel module
to provide basic infrastructure to support FPGA devices which implement
the Device Feature List.

Usually there will be different features and their sub features linked into
the DFL. This code provides common APIs for feature enumeration, it creates
a container device (FPGA base region), walks through the DFLs and creates
platform devices for feature devices (Currently it only supports two
different feature devices, FPGA Management Engine (FME) and Port which
the Accelerator Function Unit (AFU) connected to). In order to enumerate
the DFLs, the common APIs required low level driver to provide necessary
enumeration information (e.g address for each device feature list for
given device) and fill it to the dfl_fpga_enum_info data structure. Please
refer to below description for APIs added for enumeration.

Functions for enumeration information preparation:
 *dfl_fpga_enum_info_alloc
   allocate enumeration information data structure.

 *dfl_fpga_enum_info_add_dfl
   add a device feature list to dfl_fpga_enum_info data structure.

 *dfl_fpga_enum_info_free
   free dfl_fpga_enum_info data structure and related resources.

Functions for feature device enumeration:
 *dfl_fpga_feature_devs_enumerate
   enumerate feature devices and return container device.

 *dfl_fpga_feature_devs_remove
   remove feature devices under given container device.

Signed-off-by: Tim Whisonant <redacted>
Signed-off-by: Enno Luebbers <redacted>
Signed-off-by: Shiva Rao <redacted>
Signed-off-by: Christopher Rauer <redacted>
Signed-off-by: Zhang Yi <redacted>
Signed-off-by: Xiao Guangrong <redacted>
Signed-off-by: Wu Hao <redacted>

Acked-by: Alan Tull <atull@kernel.org>

---
v3: split from another patch.
    separate dfl enumeration code from original pcie driver.
    provide common data structures and APIs for enumeration.
    update device feature list parsing process according to latest hw.
    add dperf/iperf/hssi sub feature placeholder according to latest hw.
    remove build_info_add_sub_feature and other small functions.
    replace *_feature_num function with macro.
    remove writeq/readq.
v4: fix SPDX license issue
    rename files to dfl.[ch], fix typo and add more comments.
    remove static feature_info tables for FME and Port.
    remove check on next_afu link list as only FIU has next_afu ptr.
    remove unused macro in header file.
    add more comments for functions.
v5: add "dfl_" prefix to functions and data structures.
    remove port related functions from DFL framework.
    use BIT_ULL for 64bit register definition.
    save dfl_fpga_cdev in pdata for feature platform devices.
    rebase due to fpga region api changes.
v6: update time in copyright and improve function name.
    introduce dfl_devs table to save feature device info.