linux_dsm_epyc7002/Documentation/fpga/overview.txt

Linux kernel FPGA support

Alan Tull 2017

The main point of this project has been to separate the out the upper layers
that know when to reprogram a FPGA from the lower layers that know how to
reprogram a specific FPGA device.  The intention is to make this manufacturer
agnostic, understanding that of course the FPGA images are very device specific
themselves.

The framework in the kernel includes:
* low level FPGA manager drivers that know how to program a specific device
* the fpga-mgr framework they are registered with
* low level FPGA bridge drivers for hard/soft bridges which are intended to
  be disable during FPGA programming
* the fpga-bridge framework they are registered with
* the fpga-region framework which associates and controls managers and bridges
  as reconfigurable regions
* the of-fpga-region support for reprogramming FPGAs when device tree overlays
  are applied.

I would encourage you the user to add code that creates FPGA regions rather
that trying to control managers and bridges separately.
fpga: mgr: API change to replace fpga load functions with single function fpga-mgr has three methods for programming FPGAs, depending on whether the image is in a scatter gather list, a contiguous buffer, or a firmware file. This makes it difficult to write upper layers as the caller has to assume whether the FPGA image is in a sg table, as a single buffer, or a firmware file. This commit moves these parameters to struct fpga_image_info and adds a single function for programming fpgas. New functions: * fpga_mgr_load - given fpga manager and struct fpga_image_info, program the fpga. * fpga_image_info_alloc - alloc a struct fpga_image_info. * fpga_image_info_free - free a struct fpga_image_info. These three functions are unexported: * fpga_mgr_buf_load_sg * fpga_mgr_buf_load * fpga_mgr_firmware_load Also use devm_kstrdup to copy firmware_name so we aren't making assumptions about where it comes from when allocing/freeing the struct fpga_image_info. API documentation has been updated and a new document for FPGA region has been added. Signed-off-by: Alan Tull <atull@kernel.org> Acked-by: Moritz Fischer <mdf@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2017-11-16 03:20:12 +07:00			`Linux kernel FPGA support`

			`Alan Tull 2017`

			`The main point of this project has been to separate the out the upper layers`
			`that know when to reprogram a FPGA from the lower layers that know how to`
			`reprogram a specific FPGA device. The intention is to make this manufacturer`
			`agnostic, understanding that of course the FPGA images are very device specific`
			`themselves.`

			`The framework in the kernel includes:`
			`* low level FPGA manager drivers that know how to program a specific device`
			`* the fpga-mgr framework they are registered with`
			`* low level FPGA bridge drivers for hard/soft bridges which are intended to`
			`be disable during FPGA programming`
			`* the fpga-bridge framework they are registered with`
			`* the fpga-region framework which associates and controls managers and bridges`
			`as reconfigurable regions`
			`* the of-fpga-region support for reprogramming FPGAs when device tree overlays`
			`are applied.`

			`I would encourage you the user to add code that creates FPGA regions rather`
			`that trying to control managers and bridges separately.`