From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49476C55186 for ; Thu, 23 Apr 2020 01:36:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D6302074F for ; Thu, 23 Apr 2020 01:36:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587605813; bh=1QM6rFh8dJaX0N+qMjJUYWNb3erpQwXP4idZtNjT+yo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=yYhXSDbwhVXfJAeMn2DSPy5cQ51OEt3WFam8K0diXZ3GhANP8oZpvAZf9FAWjLLXN 00v3ZUALfoLV95VomxEUcOIhpv32mtKoVD26+Ag/gMQCtaT9RuBiI+5PTfZ2bKdEo+ GrFu577XDCoTegoWAGJIIUGLnxEBBDIGpKqSXwR8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726541AbgDWBgw (ORCPT ); Wed, 22 Apr 2020 21:36:52 -0400 Received: from mail-pj1-f67.google.com ([209.85.216.67]:52126 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725961AbgDWBgv (ORCPT ); Wed, 22 Apr 2020 21:36:51 -0400 Received: by mail-pj1-f67.google.com with SMTP id mq3so1730021pjb.1; Wed, 22 Apr 2020 18:36:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=TZq6bba/Za2cfM2s4UaUYLj7V0czmPB9F3lz7Q2Lzpo=; b=jK+kKWGF+kN55gPscY/Ah/q7nVK+ddvmipd43rPh8nBRM8K6TbUGdqwf2yudnetSCK Q4h8hi2StCM4LQXdYfhCtzcaL6YO13jUjNlwKEh/7nOQYJ1Wu7rSJtwGZud92u8j95+N f4uSk7O/0QEOkJea3mDvA0RnnHc2hzzaaOJmDDIyiy879mZeldq4ecMSEjAFuGMyOf7I tHfKMb1TOkc4wEQySn0LhS051eE7w/6UwyMKix7r685kmw1u1brzqrnbjkDjmxanfDKZ ZUvqRzVZdXnSYXIzuhrssX0JpLHGADumHB/8Pxns7NVVJ95rASS9dvU3Kcp/9739hZFC 6V9w== X-Gm-Message-State: AGi0PuZoxgxO9OgGtjpsjhGuWb/58m+Bltc06qMS+e1Ous7d8jSQ2ueQ RBIzwQl4SoiozeCs5d5H4OE= X-Google-Smtp-Source: APiQypLuZz9AxyqwFKbFjw5IcxAxKPR30Avx26+5vdiyhCp6KpPp1XaR6f09JwbRqlC61ZgLJQLSzA== X-Received: by 2002:a17:902:a40e:: with SMTP id p14mr1410819plq.297.1587605810907; Wed, 22 Apr 2020 18:36:50 -0700 (PDT) Received: from localhost ([2601:647:5b00:1161:a4cc:eef9:fbc0:2781]) by smtp.gmail.com with ESMTPSA id 135sm786680pfu.125.2020.04.22.18.36.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Apr 2020 18:36:49 -0700 (PDT) Date: Wed, 22 Apr 2020 18:36:48 -0700 From: Moritz Fischer To: Sascha Hauer Cc: linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, Moritz Fischer Subject: Re: How to upload fpga firmware Message-ID: <20200423013648.GA2430@epycbox.lan> References: <20200422114432.GM1694@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200422114432.GM1694@pengutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sascha, On Wed, Apr 22, 2020 at 01:44:32PM +0200, Sascha Hauer wrote: > Hi, > > I wonder what can be done with the mainline state of drivers/fpga/. The > entry to the framework seems to be fpga_mgr_load(). The only user of > this function is fpga_region_program_fpga(). This in turn is only called > in response of applying a device tree overlay. A device tree overlay is > applied with of_overlay_fdt_apply() which has no users in the Kernel. Yes. It is waiting for dt_overlays one way or another. I personally don't currently have the bandwidth to work actively on this. > My current task is to load a firmware to a FPGA. The code all seems to > be there in the Kernel, it only lacks a way to trigger it. I am not very > interested in device tree overlays since the FPGA appears as a PCI > device (although applying a dtbo could enable the PCIe controller device > tree node). Is there some mainline way to upload FPGA firmware? At the > moment we are using the attached patch to trigger loading the firmware > from userspace. Would something like this be acceptable for mainline? We've looked into this sort of patches over the years and never came to a general interface that really works. The OPAE folks (and other users I know of) usually use FPGA Manager with a higher layer on top of it that moves the bitstream into the kernel via an ioctl(). One concept I had toyed with mentally, but haven't really gotten around to implement is a 'discoverable' region, that would deal with the necessary re-enumeration via a callback and have a sysfs interface similar to what the patch below has. This would essentially cover use-cases where you have a discoverable device implemented in FPGA logic, such as say an FPGA hanging off of PCIe bus that can get loaded over USB, a CPLD or some other side-band mechanism. After loading the image you'd have to rescan the PCIe bus - which - imho is the kernel's job. What I really wanna avoid is creating another /dev/fpga0 / /dev/xdevcfg that completely leaves the kernel in the dark about the fact that it reconfigures a bit of hardware hanging off the bus. In my ideal world you'd create a pci driver that binds to your device, and creates mfd style subdevices for whatever you'd want your design to do. One of these devices would be an FPGA and a FPGA region attached to that FPGA manager. Your top level driver would co-ordinate the fact that you are re-programming parts of the FPGA and create / destroy devices as needed for the hardware contained in the bitstream. [..] > +static ssize_t firmware_name_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct fpga_region *region = to_fpga_region(dev); > + > + if (!region->info || !region->info->firmware_name) > + return 0; > + > + return sprintf(buf, "%s\n", region->info->firmware_name); > +} > + > +static ssize_t firmware_name_store(struct device *dev, > + struct device_attribute *attr, > + const char *firmware_name, size_t count) > +{ > + struct fpga_region *region = to_fpga_region(dev); > + struct fpga_image_info *info = region->info; > + int error; > + > + if (!info) { > + info = fpga_image_info_alloc(dev); > + if (!info) > + return -ENOMEM; > + } else if (info->firmware_name) { > + devm_kfree(dev, info->firmware_name); > + } > + > + info->firmware_name = devm_kstrdup(dev, firmware_name, GFP_KERNEL); > + if (!info->firmware_name) > + return -ENOMEM; > + > + if (count > 0 && info->firmware_name[count - 1] == '\n') > + info->firmware_name[count - 1] = '\0'; > + > + region->info = info; > + error = fpga_region_program_fpga(region); > + if (error) { > + devm_kfree(dev, info->firmware_name); > + info->firmware_name = NULL; > + } > + > + return error ? error : count; > +} Cheers, Moritz