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 interrupt support for port error reporting

Error reporting interrupt is very useful to notify users that some
errors are detected by the hardware. Once users are notified, they
could query hardware logged error states, no need to continuously
poll on these states.

This patch adds interrupt support for port error reporting sub feature.
It follows the common DFL interrupt notification and handling mechanism,
implements two ioctl commands below for user to query number of irqs
supported, and set/unset interrupt triggers.

Ioctls:
* DFL_FPGA_PORT_ERR_GET_IRQ_NUM
get the number of irqs, which is used to determine whether/how many
interrupts error reporting feature supports.

* DFL_FPGA_PORT_ERR_SET_IRQ
set/unset given eventfds as error interrupt triggers.

Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.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>