-===============================================================================
- FPGA Device Feature List (DFL) Framework Overview
--------------------------------------------------------------------------------
- Enno Luebbers <enno.luebbers@intel.com>
- Xiao Guangrong <guangrong.xiao@linux.intel.com>
- Wu Hao <hao.wu@intel.com>
+=================================================
+FPGA Device Feature List (DFL) Framework Overview
+=================================================
+
+Authors:
+
+- Enno Luebbers <enno.luebbers@intel.com>
+- Xiao Guangrong <guangrong.xiao@linux.intel.com>
+- Wu Hao <hao.wu@intel.com>
The Device Feature List (DFL) FPGA framework (and drivers according to this
this framework) hides the very details of low layer hardwares and provides
device MMIO space to provide an extensible way of adding features. Software can
walk through these predefined data structures to enumerate FPGA features:
FPGA Interface Unit (FIU), Accelerated Function Unit (AFU) and Private Features,
-as illustrated below:
+as illustrated below::
Header Header Header Header
+----------+ +-->+----------+ +-->+----------+ +-->+----------+
The following functions are exposed through ioctls:
- Get driver API version (DFL_FPGA_GET_API_VERSION)
- Check for extensions (DFL_FPGA_CHECK_EXTENSION)
- Program bitstream (DFL_FPGA_FME_PORT_PR)
+- Get driver API version (DFL_FPGA_GET_API_VERSION)
+- Check for extensions (DFL_FPGA_CHECK_EXTENSION)
+- Program bitstream (DFL_FPGA_FME_PORT_PR)
More functions are exposed through sysfs
(/sys/class/fpga_region/regionX/dfl-fme.n/):
The following functions are exposed through ioctls:
- Get driver API version (DFL_FPGA_GET_API_VERSION)
- Check for extensions (DFL_FPGA_CHECK_EXTENSION)
- Get port info (DFL_FPGA_PORT_GET_INFO)
- Get MMIO region info (DFL_FPGA_PORT_GET_REGION_INFO)
- Map DMA buffer (DFL_FPGA_PORT_DMA_MAP)
- Unmap DMA buffer (DFL_FPGA_PORT_DMA_UNMAP)
- Reset AFU (*DFL_FPGA_PORT_RESET)
+- Get driver API version (DFL_FPGA_GET_API_VERSION)
+- Check for extensions (DFL_FPGA_CHECK_EXTENSION)
+- Get port info (DFL_FPGA_PORT_GET_INFO)
+- Get MMIO region info (DFL_FPGA_PORT_GET_REGION_INFO)
+- Map DMA buffer (DFL_FPGA_PORT_DMA_MAP)
+- Unmap DMA buffer (DFL_FPGA_PORT_DMA_UNMAP)
+- Reset AFU (DFL_FPGA_PORT_RESET)
-*DFL_FPGA_PORT_RESET: reset the FPGA Port and its AFU. Userspace can do Port
-reset at any time, e.g. during DMA or Partial Reconfiguration. But it should
-never cause any system level issue, only functional failure (e.g. DMA or PR
-operation failure) and be recoverable from the failure.
+DFL_FPGA_PORT_RESET:
+ reset the FPGA Port and its AFU. Userspace can do Port
+ reset at any time, e.g. during DMA or Partial Reconfiguration. But it should
+ never cause any system level issue, only functional failure (e.g. DMA or PR
+ operation failure) and be recoverable from the failure.
User-space applications can also mmap() accelerator MMIO regions.
DFL Framework Overview
======================
+::
+
+----------+ +--------+ +--------+ +--------+
| FME | | AFU | | AFU | | AFU |
| Module | | Module | | Module | | Module |
| FPGA Container Device | Device Feature List
| (FPGA Base Region) | Framework
+-----------------------+
---------------------------------------------------------------------
+ ------------------------------------------------------------------
+----------------------------+
| FPGA DFL Device Module |
| (e.g. PCIE/Platform Device)|
In the example below, two DFL based FPGA devices are installed in the host. Each
fpga device has one FME and two ports (AFUs).
-FPGA regions are created under /sys/class/fpga_region/
+FPGA regions are created under /sys/class/fpga_region/::
/sys/class/fpga_region/region0
/sys/class/fpga_region/region1
(e.g. "dfl-port.n" or "dfl-fme.m" is found), then it's the base
fpga region which represents the FPGA device.
-Each base region has one FME and two ports (AFUs) as child devices:
+Each base region has one FME and two ports (AFUs) as child devices::
/sys/class/fpga_region/region0/dfl-fme.0
/sys/class/fpga_region/region0/dfl-port.0
/sys/class/fpga_region/region3/dfl-port.3
...
-In general, the FME/AFU sysfs interfaces are named as follows:
+In general, the FME/AFU sysfs interfaces are named as follows::
/sys/class/fpga_region/<regionX>/<dfl-fme.n>/
/sys/class/fpga_region/<regionX>/<dfl-port.m>/
with 'n' consecutively numbering all FMEs and 'm' consecutively numbering all
ports.
-The device nodes used for ioctl() or mmap() can be referenced through:
+The device nodes used for ioctl() or mmap() can be referenced through::
/sys/class/fpga_region/<regionX>/<dfl-fme.n>/dev
/sys/class/fpga_region/<regionX>/<dfl-port.n>/dev