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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 167B6C4361B for ; Mon, 7 Dec 2020 03:55:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE5D922C7E for ; Mon, 7 Dec 2020 03:55:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728673AbgLGDzJ (ORCPT ); Sun, 6 Dec 2020 22:55:09 -0500 Received: from mga18.intel.com ([134.134.136.126]:43162 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726483AbgLGDzJ (ORCPT ); Sun, 6 Dec 2020 22:55:09 -0500 IronPort-SDR: 31fWwcq0mBw96R2/pdvO4Em2NLr+AqV3sfeNGtT8lp10P4C0msbyjVwBqSKsvDQ8BIYw9weyxp RxC0JmNvNsag== X-IronPort-AV: E=McAfee;i="6000,8403,9827"; a="161407652" X-IronPort-AV: E=Sophos;i="5.78,398,1599548400"; d="scan'208";a="161407652" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Dec 2020 19:54:28 -0800 IronPort-SDR: iYHCXU721k6JYWNRMB744LVoeoX2cJcK497PrUvCdSJ+fgRVds5hWONO0grKxbMLw7krlmnJQN c6KE97Vs4O8A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,398,1599548400"; d="scan'208";a="362947455" Received: from yilunxu-optiplex-7050.sh.intel.com (HELO localhost) ([10.239.159.141]) by orsmga008.jf.intel.com with ESMTP; 06 Dec 2020 19:54:26 -0800 Date: Mon, 7 Dec 2020 11:49:51 +0800 From: Xu Yilun To: trix@redhat.com Cc: gregkh@linuxfoundation.org, hao.wu@intel.com, mdf@kernel.org, linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org Subject: Re: [RFC] fpga: dfl: a prototype uio driver Message-ID: <20201207034950.GA29754@yilunxu-OptiPlex-7050> References: <20201206215554.350230-1-trix@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201206215554.350230-1-trix@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 06, 2020 at 01:55:54PM -0800, trix@redhat.com wrote: > From: Tom Rix > > >From [PATCH 0/2] UIO support for dfl devices > https://lore.kernel.org/linux-fpga/1602828151-24784-1-git-send-email-yilun.xu@intel.com/ > > Here is an idea to have uio support with no driver override. > > This makes UIO the primary driver interface because every feature > will have one and makes the existing platform driver interface > secondary. There will be a new burden for locking write access when > they compete. > > Example shows finding the fpga's temperture. Hi Tom: Thanks for the idea and detailed illustrate with the patch. I see it abandons the driver_override and expose all the DFL devices to userspace by UIO. I'd like to see if we could get some more comments on it. Thanks, Yilun > > Signed-off-by: Tom Rix > --- > drivers/fpga/dfl-fme-main.c | 9 +++- > drivers/fpga/dfl-uio.c | 96 +++++++++++++++++++++++++++++++++++++ > drivers/fpga/dfl.c | 44 ++++++++++++++++- > drivers/fpga/dfl.h | 9 ++++ > uio.c | 56 ++++++++++++++++++++++ > 5 files changed, 212 insertions(+), 2 deletions(-) > create mode 100644 drivers/fpga/dfl-uio.c > create mode 100644 uio.c > > diff --git a/drivers/fpga/dfl-fme-main.c b/drivers/fpga/dfl-fme-main.c > index 037dc4f946f0..3323e90a18c4 100644 > --- a/drivers/fpga/dfl-fme-main.c > +++ b/drivers/fpga/dfl-fme-main.c > @@ -709,12 +709,18 @@ static int fme_probe(struct platform_device *pdev) > if (ret) > goto dev_destroy; > > - ret = dfl_fpga_dev_ops_register(pdev, &fme_fops, THIS_MODULE); > + ret = dfl_fpga_dev_feature_init_uio(pdev, DFH_TYPE_FIU); > if (ret) > goto feature_uinit; > > + ret = dfl_fpga_dev_ops_register(pdev, &fme_fops, THIS_MODULE); > + if (ret) > + goto feature_uinit_uio; > + > return 0; > > +feature_uinit_uio: > + dfl_fpga_dev_feature_uinit_uio(pdev, DFH_TYPE_FIU); > feature_uinit: > dfl_fpga_dev_feature_uinit(pdev); > dev_destroy: > @@ -726,6 +732,7 @@ exit: > static int fme_remove(struct platform_device *pdev) > { > dfl_fpga_dev_ops_unregister(pdev); > + dfl_fpga_dev_feature_uinit_uio(pdev, DFH_TYPE_FIU); > dfl_fpga_dev_feature_uinit(pdev); > fme_dev_destroy(pdev); > > diff --git a/drivers/fpga/dfl-uio.c b/drivers/fpga/dfl-uio.c > new file mode 100644 > index 000000000000..7610ee0b19dc > --- /dev/null > +++ b/drivers/fpga/dfl-uio.c > @@ -0,0 +1,96 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * prototype dfl uio driver > + * > + * Copyright Tom Rix 2020 > + */ > +#include > +#include "dfl.h" > + > +static irqreturn_t dfl_uio_handler(int irq, struct uio_info *info) > +{ > + return IRQ_HANDLED; > +} > + > +static int dfl_uio_mmap(struct uio_info *info, struct vm_area_struct *vma) > +{ > + int ret = -ENODEV; > + return ret; > +} > + > +static int dfl_uio_open(struct uio_info *info, struct inode *inode) > +{ > + int ret = -ENODEV; > + struct dfl_feature *feature = container_of(info, struct dfl_feature, uio); > + if (feature->dev) > + mutex_lock(&feature->lock); > + > + ret = 0; > + return ret; > +} > + > +static int dfl_uio_release(struct uio_info *info, struct inode *inode) > +{ > + int ret = -ENODEV; > + struct dfl_feature *feature = container_of(info, struct dfl_feature, uio); > + if (feature->dev) > + mutex_unlock(&feature->lock); > + > + ret = 0; > + return ret; > +} > + > +static int dfl_uio_irqcontrol(struct uio_info *info, s32 irq_on) > +{ > + int ret = -ENODEV; > + return ret; > +} > + > +int dfl_uio_add(struct dfl_feature *feature) > +{ > + struct uio_info *uio = &feature->uio; > + struct resource *res = > + &feature->dev->resource[feature->resource_index]; > + int ret = 0; > + > + uio->name = kasprintf(GFP_KERNEL, "dfl-uio-%llx", feature->id); > + if (!uio->name) { > + ret = -ENOMEM; > + goto exit; > + } > + > + uio->version = "0.1"; > + uio->mem[0].memtype = UIO_MEM_PHYS; > + uio->mem[0].addr = res->start & PAGE_MASK; > + uio->mem[0].offs = res->start & ~PAGE_MASK; > + uio->mem[0].size = (uio->mem[0].offs + resource_size(res) > + + PAGE_SIZE - 1) & PAGE_MASK; > + /* How are nr_irqs > 1 handled ??? */ > + if (feature->nr_irqs == 1) > + uio->irq = feature->irq_ctx[0].irq; > + uio->handler = dfl_uio_handler; > + //uio->mmap = dfl_uio_mmap; > + uio->open = dfl_uio_open; > + uio->release = dfl_uio_release; > + uio->irqcontrol = dfl_uio_irqcontrol; > + > + ret = uio_register_device(&feature->dev->dev, uio); > + if (ret) > + goto err_register; > + > +exit: > + return ret; > +err_register: > + kfree(uio->name); > + goto exit; > +} > +EXPORT_SYMBOL_GPL(dfl_uio_add); > + > +int dfl_uio_remove(struct dfl_feature *feature) > +{ > + uio_unregister_device(&feature->uio); > + kfree(feature->uio.name); > + return 0; > +} > +EXPORT_SYMBOL_GPL(dfl_uio_remove); > + > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > index 1305be48037d..af2cd3d1b5f6 100644 > --- a/drivers/fpga/dfl.c > +++ b/drivers/fpga/dfl.c > @@ -603,6 +603,7 @@ static int dfl_feature_instance_init(struct platform_device *pdev, > } > > feature->ops = drv->ops; > + mutex_init(&feature->lock); > > return ret; > } > @@ -663,10 +664,51 @@ exit: > } > EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_init); > > +int dfl_fpga_dev_feature_init_uio(struct platform_device *pdev, int dfh_type) { > + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); > + struct dfl_feature *feature; > + int ret; > + > + dfl_fpga_dev_for_each_feature(pdata, feature) { > + if (dfh_type == DFH_TYPE_FIU) { > + if (feature->id == FEATURE_ID_FIU_HEADER || > + feature->id == FEATURE_ID_AFU) > + continue; > + > + ret = dfl_uio_add(feature); > + if (ret) > + goto exit; > + } > + } > + > + return 0; > +exit: > + dfl_fpga_dev_feature_uinit_uio(pdev, dfh_type); > + return ret; > +} > +EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_init_uio); > + > +int dfl_fpga_dev_feature_uinit_uio(struct platform_device *pdev, int dfh_type) { > + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); > + struct dfl_feature *feature; > + int ret = 0; > + > + dfl_fpga_dev_for_each_feature(pdata, feature) { > + if (dfh_type == DFH_TYPE_FIU) { > + if (feature->id == FEATURE_ID_FIU_HEADER || > + feature->id == FEATURE_ID_AFU) > + continue; > + > + ret |= dfl_uio_remove(feature); > + } > + } > + return ret; > +} > +EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_uinit_uio); > + > static void dfl_chardev_uinit(void) > { > int i; > - > for (i = 0; i < DFL_FPGA_DEVT_MAX; i++) > if (MAJOR(dfl_chrdevs[i].devt)) { > unregister_chrdev_region(dfl_chrdevs[i].devt, > diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h > index a85d1cd7a130..fde0fc902d4d 100644 > --- a/drivers/fpga/dfl.h > +++ b/drivers/fpga/dfl.h > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > #include > > /* maximum supported number of ports */ > @@ -232,6 +233,7 @@ struct dfl_feature_irq_ctx { > * struct dfl_feature - sub feature of the feature devices > * > * @dev: ptr to pdev of the feature device which has the sub feature. > + * @uio: uio interface for feature. > * @id: sub feature id. > * @index: unique identifier for an sub feature within the feature device. > * It is possible that multiply sub features with same feature id are > @@ -248,6 +250,8 @@ struct dfl_feature_irq_ctx { > */ > struct dfl_feature { > struct platform_device *dev; > + struct uio_info uio; > + struct mutex lock; /* serialize dev and uio */ > u64 id; > int index; > int resource_index; > @@ -360,6 +364,11 @@ void dfl_fpga_dev_feature_uinit(struct platform_device *pdev); > int dfl_fpga_dev_feature_init(struct platform_device *pdev, > struct dfl_feature_driver *feature_drvs); > > +int dfl_fpga_dev_feature_init_uio(struct platform_device *pdev, int dfh_type); > +int dfl_fpga_dev_feature_uinit_uio(struct platform_device *pdev, int dfh_type); > +int dfl_uio_add(struct dfl_feature *feature); > +int dfl_uio_remove(struct dfl_feature *feature); > + > int dfl_fpga_dev_ops_register(struct platform_device *pdev, > const struct file_operations *fops, > struct module *owner); > diff --git a/uio.c b/uio.c > new file mode 100644 > index 000000000000..50210aab4822 > --- /dev/null > +++ b/uio.c > @@ -0,0 +1,56 @@ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +int main() > +{ > + int fd; > + uint64_t *ptr; > + unsigned page_size=sysconf(_SC_PAGESIZE); > + struct stat sb; > + > + /* > + * this is fid 1, thermal mgt > + * ex/ > + * # cat /sys/class/hwmon/hwmon3/temp1_input > + * 39000 > + */ > + fd = open("/dev/uio0", O_RDONLY|O_SYNC); > + if (fd < 0) { > + perror("uio open:"); > + return errno; > + } > + > + ptr = (uint64_t *) mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0); > + if (!ptr) { > + perror("uio mmap:"); > + } else { > + > + /* from dfl-fme-main.c : > + * > + * #define FME_THERM_RDSENSOR_FMT1 0x10 > + * #define FPGA_TEMPERATURE GENMASK_ULL(6, 0) > + * > + * case hwmon_temp_input: > + * v = readq(feature->ioaddr + FME_THERM_RDSENSOR_FMT1); > + * *val = (long)(FIELD_GET(FPGA_TEMPERATURE, v) * 1000); > + * break; > + */ > + uint64_t v = ptr[2]; > + v &= (1 << 6) -1; > + v *= 1000; > + printf("Temperature %d\n", v); > + > + munmap(ptr, page_size); > + } > + if (close(fd)) > + perror("uio close:"); > + > + return errno; > +} > -- > 2.18.4