fpga: dfl: more kernel-doc corrections

Fix more kernel-doc warnings in drivers/fpga/:

$ ./scripts/kernel-doc -none drivers/fpga/*
drivers/fpga/dfl-afu.h:61: warning: expecting prototype for struct fpga_afu_dma_region. Prototype was for struct dfl_afu_dma_region instead
drivers/fpga/dfl-afu-region.c:52: warning: Function parameter or member 'pdata' not described in 'afu_mmio_region_add'
drivers/fpga/dfl-fme-perf.c:161: warning: Function parameter or member 'node' not described in 'fme_perf_priv'
drivers/fpga/dfl-fme-pr.h:70: warning: expecting prototype for struct dfl_fme_bridge_pdata. Prototype was for struct dfl_fme_br_pdata instead
drivers/fpga/dfl.h:256: warning: Function parameter or member 'revision' not described in 'dfl_feature'

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20230114155444.794712-1-yilun.xu@intel.com

fpga: dfl: afu: harden port enable logic

Port enable is not complete until ACK = 0. Change
__afu_port_enable() to guarantee that the enable process
is complete by polling for ACK == 0.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Acked-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

fpga: dfl: afu: add error reporting support.

Error reporting is one important private feature, it reports error
detected on port and accelerated function unit (AFU). It introduces
several sysfs interfaces to allow userspace to check and clear
errors detected by hardware.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

fpga: dfl: afu: expose __afu_port_enable/disable function.

As these two functions are used by other private features within the
same driver module but different driver files. e.g. in error reporting
private feature, it requires to clear errors when port is in reset.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Moritz Fischer <mdf@kernel.org>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

fpga: dfl: afu: add DFL_FPGA_PORT_DMA_MAP/UNMAP ioctls support

DMA memory regions are required for Accelerated Function Unit (AFU) usage.
These two ioctls allow user space applications to map user memory regions
for dma, and unmap them after use. Iova is returned from driver to user
space application via DFL_FPGA_PORT_DMA_MAP ioctl. Application needs to
unmap it after use, otherwise, driver will unmap them in device file
release operation.

Each AFU has its own rb tree to keep track of its mapped DMA regions.

Ioctl interfaces:
* DFL_FPGA_PORT_DMA_MAP
Do the dma mapping per user_addr and length provided by user.
Return iova in provided struct dfl_fpga_port_dma_map.

* DFL_FPGA_PORT_DMA_UNMAP
Unmap the dma region per iova provided by user.

Signed-off-by: Tim Whisonant <tim.whisonant@intel.com>
Signed-off-by: Enno Luebbers <enno.luebbers@intel.com>
Signed-off-by: Shiva Rao <shiva.rao@intel.com>
Signed-off-by: Christopher Rauer <christopher.rauer@intel.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fpga: dfl: afu: add afu sub feature support

User Accelerated Function Unit sub feature exposes the MMIO region of
the AFU. After valid PR bitstream is programmed and the port is enabled,
then this MMIO region could be accessed.

This patch adds support to enumerate the AFU MMIO region and expose it
to userspace via mmap file operation. Below interfaces are exposed to user:

Sysfs interface:
* /sys/class/fpga_region/<regionX>/<dfl-port.x>/afu_id
Read-only. Indicate which PR bitstream is programmed to this AFU.

Ioctl interfaces:
* DFL_FPGA_PORT_GET_INFO
Provide info to userspace on the number of supported region.
Only UAFU region is supported now.

* DFL_FPGA_PORT_GET_REGION_INFO
Provide region information, including access permission, region size,
offset from the start of device fd.

Signed-off-by: Tim Whisonant <tim.whisonant@intel.com>
Signed-off-by: Enno Luebbers <enno.luebbers@intel.com>
Signed-off-by: Shiva Rao <shiva.rao@intel.com>
Signed-off-by: Christopher Rauer <christopher.rauer@intel.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>