From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Tull Subject: Re: [PATCH v5 20/28] fpga: dfl: add fpga bridge platform driver for FME Date: Wed, 23 May 2018 16:06:17 -0500 Message-ID: References: <1525229431-3087-1-git-send-email-hao.wu@intel.com> <1525229431-3087-21-git-send-email-hao.wu@intel.com> <20180523152841.GA23834@hao-dev> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20180523152841.GA23834@hao-dev> Sender: linux-kernel-owner@vger.kernel.org To: Wu Hao Cc: Moritz Fischer , linux-fpga@vger.kernel.org, linux-kernel , linux-api@vger.kernel.org, "Kang, Luwei" , "Zhang, Yi Z" , Tim Whisonant , Enno Luebbers , Shiva Rao , Christopher Rauer List-Id: linux-api@vger.kernel.org On Wed, May 23, 2018 at 10:28 AM, Wu Hao wrote: > On Wed, May 23, 2018 at 10:15:00AM -0500, Alan Tull wrote: >> On Tue, May 1, 2018 at 9:50 PM, Wu Hao wrote: >> >> Hi Hao, >> >> > This patch adds fpga bridge platform driver for FPGA Management Engine. >> > It implements the enable_set callback for fpga bridge. >> > >> > Signed-off-by: Tim Whisonant >> > Signed-off-by: Enno Luebbers >> > Signed-off-by: Shiva Rao >> > Signed-off-by: Christopher Rauer >> > Signed-off-by: Wu Hao >> > Acked-by: Alan Tull >> > Acked-by: Moritz Fischer >> > --- >> > v3: rename driver to fpga-dfl-fme-br >> > remove useless dev_dbg in probe function. >> > rebased due to fpga api change. >> > v4: rename to dfl-fme-br and fix SPDX license issue >> > include dfl-fme-pr.h instead of dfl-fme.h >> > add Acked-by from Alan and Moritz >> > v5: rebase due to API changes. >> > defer port and its ops finding when really need. >> > --- >> > drivers/fpga/Kconfig | 6 +++ >> > drivers/fpga/Makefile | 1 + >> > drivers/fpga/dfl-fme-br.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++ >> > 3 files changed, 121 insertions(+) >> > create mode 100644 drivers/fpga/dfl-fme-br.c >> > >> > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig >> > index 89f76e8..a8f939a 100644 >> > --- a/drivers/fpga/Kconfig >> > +++ b/drivers/fpga/Kconfig >> > @@ -156,6 +156,12 @@ config FPGA_DFL_FME_MGR >> > help >> > Say Y to enable FPGA Manager driver for FPGA Management Engine. >> > >> > +config FPGA_DFL_FME_BRIDGE >> > + tristate "FPGA DFL FME Bridge Driver" >> > + depends on FPGA_DFL_FME >> > + help >> > + Say Y to enable FPGA Bridge driver for FPGA Management Engine. >> > + >> > config FPGA_DFL_PCI >> > tristate "FPGA Device Feature List (DFL) PCIe Device Driver" >> > depends on PCI && FPGA_DFL >> > diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile >> > index f82814a..75096e9 100644 >> > --- a/drivers/fpga/Makefile >> > +++ b/drivers/fpga/Makefile >> > @@ -32,6 +32,7 @@ obj-$(CONFIG_OF_FPGA_REGION) += of-fpga-region.o >> > obj-$(CONFIG_FPGA_DFL) += dfl.o >> > obj-$(CONFIG_FPGA_DFL_FME) += dfl-fme.o >> > obj-$(CONFIG_FPGA_DFL_FME_MGR) += dfl-fme-mgr.o >> > +obj-$(CONFIG_FPGA_DFL_FME_BRIDGE) += dfl-fme-br.o >> > >> > dfl-fme-objs := dfl-fme-main.o dfl-fme-pr.o >> > >> > diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c >> > new file mode 100644 >> > index 0000000..5c51b08 >> > --- /dev/null >> > +++ b/drivers/fpga/dfl-fme-br.c >> > @@ -0,0 +1,114 @@ >> > +// SPDX-License-Identifier: GPL-2.0 >> > +/* >> > + * FPGA Bridge Driver for FPGA Management Engine (FME) >> > + * >> > + * Copyright (C) 2017 Intel Corporation, Inc. >> > + * >> > + * Authors: >> > + * Wu Hao >> > + * Joseph Grecco >> > + * Enno Luebbers >> > + * Tim Whisonant >> > + * Ananda Ravuri >> > + * Henry Mitchel >> > + */ >> > + >> > +#include >> > +#include >> > + >> > +#include "dfl.h" >> > +#include "dfl-fme-pr.h" >> > + >> > +struct fme_br_priv { >> > + struct dfl_fme_br_pdata *pdata; >> > + struct dfl_fpga_port_ops *port_ops; >> > + struct platform_device *port_pdev; >> > +}; >> > + >> > +static int fme_bridge_enable_set(struct fpga_bridge *bridge, bool enable) >> > +{ >> > + struct fme_br_priv *priv = bridge->priv; >> > + struct platform_device *port_pdev; >> > + struct dfl_fpga_port_ops *ops; >> > + >> > + if (!priv->port_pdev) { >> > + port_pdev = dfl_fpga_cdev_find_port(priv->pdata->cdev, >> > + &priv->pdata->port_id, >> > + dfl_fpga_check_port_id); >> > + if (!port_pdev) >> > + return -ENODEV; >> > + >> > + priv->port_pdev = port_pdev; >> > + } >> > + >> > + if (priv->port_pdev && !priv->port_ops) { >> > + ops = dfl_fpga_get_port_ops(priv->port_pdev); >> > + if (!ops || !ops->enable_set) >> > + return -ENOENT; >> > + >> > + priv->port_ops = ops; >> > + } >> >> This is saving some pointers. Is it possible that the port_pdev or >> port_ops could go away? > > Hi Alan > > Thanks for the comments. > > The find_port function will get the port device to prevent that. > You can see put device in remove function. And it's similar for the > port ops. In dfl_fpga_get_port_ops function, it will prevent unexpected > port ops removing by try module get. OK, good, and I see the find_port function documents that put_device is needed, so that's good too. When we previously discussed this [1] you described a procedure of hot-unplugging the VF AFU from the VM and turning it back to PF before doing the FPGA programming. Some comments on that would be helpful, maybe located with the port_ops functions. [1] https://lkml.org/lkml/2018/4/6/180 > >> >> Also, the port ops routines probably should be named >> dfl_fpga_port_ops_get/find_port/etc >> > > Hm.. as I see there are functions named as get_device(), put_device(), so > I just name it as ..._get_port_ops and ..._put_port_ops in similar way. :) > If you think that could be a better name, it's fine for me to change them. Yes, I've seen that too. I think keeping the prefix the same helps to organize the namespace. Plus :) if I'm grepping through the code, I can be lazy and not have to use a regex to find the port ops functions. Alan > > Thanks > Hao > >> Alan >> >> > + >> > + return priv->port_ops->enable_set(priv->port_pdev, enable); >> > +} >> > + >> > +static const struct fpga_bridge_ops fme_bridge_ops = { >> > + .enable_set = fme_bridge_enable_set, >> > +}; >> > + >> > +static int fme_br_probe(struct platform_device *pdev) >> > +{ >> > + struct device *dev = &pdev->dev; >> > + struct fme_br_priv *priv; >> > + struct fpga_bridge *br; >> > + int ret; >> > + >> > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); >> > + if (!priv) >> > + return -ENOMEM; >> > + >> > + priv->pdata = dev_get_platdata(dev); >> > + >> > + br = fpga_bridge_create(dev, "DFL FPGA FME Bridge", >> > + &fme_bridge_ops, priv); >> > + if (!br) >> > + return -ENOMEM; >> > + >> > + platform_set_drvdata(pdev, br); >> > + >> > + ret = fpga_bridge_register(br); >> > + if (ret) >> > + fpga_bridge_free(br); >> > + >> > + return ret; >> > +} >> > + >> > +static int fme_br_remove(struct platform_device *pdev) >> > +{ >> > + struct fpga_bridge *br = platform_get_drvdata(pdev); >> > + struct fme_br_priv *priv = br->priv; >> > + >> > + fpga_bridge_unregister(br); >> > + >> > + if (priv->port_pdev) >> > + put_device(&priv->port_pdev->dev); >> > + if (priv->port_ops) >> > + dfl_fpga_put_port_ops(priv->port_ops); >> > + >> > + return 0; >> > +} >> > + >> > +static struct platform_driver fme_br_driver = { >> > + .driver = { >> > + .name = DFL_FPGA_FME_BRIDGE, >> > + }, >> > + .probe = fme_br_probe, >> > + .remove = fme_br_remove, >> > +}; >> > + >> > +module_platform_driver(fme_br_driver); >> > + >> > +MODULE_DESCRIPTION("FPGA Bridge for DFL FPGA Management Engine"); >> > +MODULE_AUTHOR("Intel Corporation"); >> > +MODULE_LICENSE("GPL v2"); >> > +MODULE_ALIAS("platform:dfl-fme-bridge"); >> > -- >> > 1.8.3.1 >> >