Date: Fri, 10 Mar 2017 09:11:54 -0800 (PST)
From: matthew.gerlach@linux.intel.com
To: Yi Li <yi1.li@linux.intel.com>
cc: ming.lei@canonical.com, mcgrof@kernel.org, gregkh@linuxfoundation.org,
        atull@opensource.altera.com, moritz.fischer@ettus.com,
        linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org
Subject: Re: [RFC 0/2] Add streaming API for firmware and FPGA manager 
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On Thu, 9 Mar 2017, yi1.li@linux.intel.com wrote:

> From: Yi Li <yi1.li@linux.intel.com>


Hi Yi,

This functionality is extremely helpful. I am working with a
firmware image of about 90 MBs, and even using scatter-gather instead of a 
continguous piece of memory is a lot of memory.

Matthew Gerlach

>
> As the FPGA hardware advances, the firmware image size grows (hundres
> of MBs or more). It could be an issue for kernel to allocate a big
> buffer to load the whole firmware file.
> Here is an attempt to read the firmware file into a small buffer and
> program the FPGA in a loop (or so call the streaming mode). It should not
> be a performance hit for FPGA programing since the majority of time
> spend is with the FPGA CvP/PR-IP interface.
>
> pseudo code in fpga manager:
> while (size > 0) {
> 	ret = stream_firmware(&fw, image_name, dev, offset, streamsize);
> 	ret = mgr->mops->write(mgr, fw->data, fw->size);
> 	offset += fw->size;
> 	size -= fw->size;
> }
>
> Thanks,
> Yi
>
> Yi Li (2):
>  firmware class: Add stream_firmware API.
>  fpga manager: Add fpga_mgr_firmware_stream API
>
> drivers/base/firmware_class.c | 128 ++++++++++++++++++++++++++++++++++++++++++
> drivers/fpga/fpga-mgr.c       |  77 +++++++++++++++++++++++++
> include/linux/firmware.h      |   2 +
> include/linux/fpga/fpga-mgr.h |   4 ++
> 4 files changed, 211 insertions(+)
>
> -- 
> 2.7.4
>
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