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=-18.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 A37F2C47082 for ; Sat, 5 Jun 2021 15:48:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75C32613DF for ; Sat, 5 Jun 2021 15:48:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229931AbhFEPuV (ORCPT ); Sat, 5 Jun 2021 11:50:21 -0400 Received: from mga14.intel.com ([192.55.52.115]:13712 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229930AbhFEPuU (ORCPT ); Sat, 5 Jun 2021 11:50:20 -0400 IronPort-SDR: Qy1MTW+A0g5jqBXFBSysaLwqgCgprtYe5qAn2D6K/xNaQuU00DZvgmiwal5aN5238NM0V4icLh 2acr/oAa/PDQ== X-IronPort-AV: E=McAfee;i="6200,9189,10006"; a="204256930" X-IronPort-AV: E=Sophos;i="5.83,251,1616482800"; d="scan'208";a="204256930" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jun 2021 08:48:30 -0700 IronPort-SDR: PkmiA1+xYzHV7WvPfAlA/Cy5btdZdHYulCwJkXFOg+PvrCmhhQJIAbp5uH5NJnJM6v3EFRltQM 32PO9OEceLHg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,251,1616482800"; d="scan'208";a="484268116" Received: from yilunxu-optiplex-7050.sh.intel.com (HELO localhost) ([10.239.159.162]) by fmsmga002.fm.intel.com with ESMTP; 05 Jun 2021 08:48:27 -0700 Date: Sat, 5 Jun 2021 23:42:53 +0800 From: Xu Yilun To: Russ Weight Cc: Tom Rix , mdf@kernel.org, linux-fpga@vger.kernel.org, lgoncalv@redhat.com, hao.wu@intel.com, matthew.gerlach@intel.com, richard.gong@intel.com Subject: Re: [PATCH v4 1/3] fpga: mgr: Use standard dev_release for class driver Message-ID: <20210605154253.GA1973240@yilunxu-OptiPlex-7050> References: <20210528215755.839712-1-russell.h.weight@intel.com> <20210528215755.839712-2-russell.h.weight@intel.com> <3741e1dd-e010-79c0-7d27-930192f632a8@redhat.com> <92ced1b2-1ea7-58ce-32d3-413ee474efc8@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org On Thu, Jun 03, 2021 at 03:45:17PM -0700, Russ Weight wrote: > > > On 6/1/21 5:38 PM, Russ Weight wrote: > > > > On 6/1/21 4:24 PM, Tom Rix wrote: > >> On 5/28/21 2:57 PM, Russ Weight wrote: > >>> The FPGA manager class driver data structure is being treated as a > >>> managed resource instead of using standard dev_release call-back > >>> to release the class data structure. This change removes the > >>> managed resource code for the freeing of the class data structure > >>> and combines the create() and register() functions into a single > >>> register() function. > >>> > >>> The devm_fpga_mgr_register() function is retained. > >>> > >>> Signed-off-by: Russ Weight > >>> --- > >>> v4: > >>>    - Added the compat_id parameter to fpga_mgr_register() and > >> On a refactor, it is best to do the refactoring as mechanically as possible. > >> > >> While compat_id may be useful, it should be done in a separate patch. > > These would have to be included with the changes merge the create and register > > functions into a single function. > > > >> > >> Unless it is really needed for your next security update patch consider resubmitting later > >> > >>>      devm_fpga_mgr_register() to ensure that the compat_id is set before > >>>      the device_register() call. > >>> v3: > >>>    - Cleaned up comment header for fpga_mgr_register() > >>>    - Fix error return on ida_simple_get() failure > >>> v2: > >>>    - Restored devm_fpga_mgr_register() functionality, adapted for the combined > >>>      create/register functionality. > >>>    - All previous callers of devm_fpga_mgr_register() will continue to call > >>>      devm_fpga_mgr_register(). > >>>    - replaced unnecessary ternary operators in return statements with standard > >>>      if conditions. > >>> --- > >>>   drivers/fpga/altera-cvp.c        |  12 +-- > >>>   drivers/fpga/altera-pr-ip-core.c |   9 +- > >>>   drivers/fpga/altera-ps-spi.c     |  10 +- > >>>   drivers/fpga/dfl-fme-mgr.c       |  12 +-- > >>>   drivers/fpga/fpga-mgr.c          | 168 +++++++++---------------------- > >>>   drivers/fpga/ice40-spi.c         |  10 +- > >>>   drivers/fpga/machxo2-spi.c       |  10 +- > >>>   drivers/fpga/socfpga-a10.c       |  16 ++- > >>>   drivers/fpga/socfpga.c           |  10 +- > >>>   drivers/fpga/stratix10-soc.c     |  15 +-- > >>>   drivers/fpga/ts73xx-fpga.c       |  10 +- > >>>   drivers/fpga/xilinx-spi.c        |  12 +-- > >>>   drivers/fpga/zynq-fpga.c         |  16 ++- > >>>   drivers/fpga/zynqmp-fpga.c       |  10 +- > >>>   include/linux/fpga/fpga-mgr.h    |  19 ++-- > >>>   15 files changed, 120 insertions(+), 219 deletions(-) > >> ./Documentation/driver-api/fpga/fpga-mgr.rst > >> > >> still refers to fpga_mgr_create. > > Thanks for catching that. > > > >>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c > >>> index 4e0edb60bfba..25eaa97ae7aa 100644 > >>> --- a/drivers/fpga/altera-cvp.c > >>> +++ b/drivers/fpga/altera-cvp.c > >>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev, > >>>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s", > >>>            ALTERA_CVP_MGR_NAME, pci_name(pdev)); > >>>   -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name, > >>> -                   &altera_cvp_ops, conf); > >>> -    if (!mgr) { > >>> -        ret = -ENOMEM; > >>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name, NULL, > >>> +                &altera_cvp_ops, conf); > >>> +    if (IS_ERR(mgr)) { > >>> +        ret = PTR_ERR(mgr); > >>>           goto err_unmap; > >>>       } > >>>         pci_set_drvdata(pdev, mgr); > >>>   -    ret = fpga_mgr_register(mgr); > >>> -    if (ret) > >>> -        goto err_unmap; > >>> - > >>>       return 0; > >>>     err_unmap: > >>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c > >>> index 5b130c4d9882..bfd4de1e7ac5 100644 > >>> --- a/drivers/fpga/altera-pr-ip-core.c > >>> +++ b/drivers/fpga/altera-pr-ip-core.c > >>> @@ -191,11 +191,12 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base) > >>>           (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT, > >>>           (int)(val & ALT_PR_CSR_PR_START)); > >>>   -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), NULL, > >>> +                     &alt_pr_ops, priv); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(dev, mgr); > >>> +    return 0; > >>>   } > >>>   EXPORT_SYMBOL_GPL(alt_pr_register); > >>>   diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c > >>> index 23bfd4d1ad0f..e6fc7208213c 100644 > >>> --- a/drivers/fpga/altera-ps-spi.c > >>> +++ b/drivers/fpga/altera-ps-spi.c > >>> @@ -302,12 +302,12 @@ static int altera_ps_probe(struct spi_device *spi) > >>>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s", > >>>            dev_driver_string(&spi->dev), dev_name(&spi->dev)); > >>>   -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name, > >>> -                   &altera_ps_ops, conf); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name, NULL, > >>> +                     &altera_ps_ops, conf); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(&spi->dev, mgr); > >>> +    return 0; > >>>   } > >>>     static const struct spi_device_id altera_ps_spi_ids[] = { > >>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c > >>> index d5861d13b306..c9b98afa7d50 100644 > >>> --- a/drivers/fpga/dfl-fme-mgr.c > >>> +++ b/drivers/fpga/dfl-fme-mgr.c > >>> @@ -308,14 +308,12 @@ static int fme_mgr_probe(struct platform_device *pdev) > >>>         fme_mgr_get_compat_id(priv->ioaddr, compat_id); > >>>   -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager", > >>> -                   &fme_mgr_ops, priv); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> - > >>> -    mgr->compat_id = compat_id; > >>> +    mgr = devm_fpga_mgr_register(dev, "DFL FME FPGA Manager", compat_id, > >>> +                     &fme_mgr_ops, priv); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(dev, mgr); > >>> +    return 0; > >>>   } > >>>     static struct platform_driver fme_mgr_driver = { > >>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c > >>> index b85bc47c91a9..d6d64ce34417 100644 > >>> --- a/drivers/fpga/fpga-mgr.c > >>> +++ b/drivers/fpga/fpga-mgr.c > >>> @@ -550,20 +550,22 @@ void fpga_mgr_unlock(struct fpga_manager *mgr) > >>>   EXPORT_SYMBOL_GPL(fpga_mgr_unlock); > >>>     /** > >>> - * fpga_mgr_create - create and initialize a FPGA manager struct > >>> + * fpga_mgr_register - create and register a FPGA Manager device > >>>    * @dev:    fpga manager device from pdev > >>>    * @name:    fpga manager name > >>> + * @compat_id:    FPGA manager id for compatibility check. > >> for consistency, use lowercase fpga > >> > >> similar issue below. > > OK > > > >>>    * @mops:    pointer to structure of fpga manager ops > >>>    * @priv:    fpga manager private data > >>>    * > >>> - * The caller of this function is responsible for freeing the struct with > >>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended. > >>> + * The caller of this function is responsible for calling fpga_mgr_unregister(). > >>> + * Using devm_fpga_mgr_register instead is recommended. > >>>    * > >>> - * Return: pointer to struct fpga_manager or NULL > >>> + * Return: struct fpga_manager pointer on success, ERR_PTR() on error. > >>>    */ > >>> -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name, > >>> -                     const struct fpga_manager_ops *mops, > >>> -                     void *priv) > >>> +struct fpga_manager * > >>> +fpga_mgr_register(struct device *dev, const char *name, > >>> +          struct fpga_compat_id *compat_id, > >>> +          const struct fpga_manager_ops *mops, void *priv) > >>>   { > >>>       struct fpga_manager *mgr; > >>>       int id, ret; > >>> @@ -572,29 +574,31 @@ struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name, > >>>           !mops->write_init || (!mops->write && !mops->write_sg) || > >>>           (mops->write && mops->write_sg)) { > >>>           dev_err(dev, "Attempt to register without fpga_manager_ops\n"); > >>> -        return NULL; > >>> +        return ERR_PTR(-EINVAL); > >>>       } > >>>         if (!name || !strlen(name)) { > >>>           dev_err(dev, "Attempt to register with no name!\n"); > >>> -        return NULL; > >>> +        return ERR_PTR(-EINVAL); > >>>       } > >>>         mgr = kzalloc(sizeof(*mgr), GFP_KERNEL); > >>>       if (!mgr) > >>> -        return NULL; > >>> +        return ERR_PTR(-ENOMEM); > >>>         id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL); > >>> -    if (id < 0) > >>> +    if (id < 0) { > >>> +        ret = id; > >> ida_* returns a normal error, so needs a wrapping in > >> > >> ret = ERR_PTR(id) > > Thanks - I'll fix that > Actually, if you follow the "goto error_kfree", you will see that ret is > wrapped in ERR_PTR() in the return statement, so id does not need to be > wrapped here. > > > > >>>           goto error_kfree; > >>> +    } > >>>         mutex_init(&mgr->ref_mutex); > >>>         mgr->name = name; > >>> +    mgr->compat_id = compat_id; > >>>       mgr->mops = mops; > >>>       mgr->priv = priv; > >>>   -    device_initialize(&mgr->dev); > >>>       mgr->dev.class = fpga_mgr_class; > >>>       mgr->dev.groups = mops->groups; > >>>       mgr->dev.parent = dev; > >>> @@ -605,84 +609,6 @@ struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name, > >>>       if (ret) > >>>           goto error_device; > >>>   -    return mgr; > >>> - > >>> -error_device: > >>> -    ida_simple_remove(&fpga_mgr_ida, id); > >>> -error_kfree: > >>> -    kfree(mgr); > >>> - > >>> -    return NULL; > >>> -} > >>> -EXPORT_SYMBOL_GPL(fpga_mgr_create); > >>> - > >>> -/** > >>> - * fpga_mgr_free - free a FPGA manager created with fpga_mgr_create() > >>> - * @mgr:    fpga manager struct > >>> - */ > >>> -void fpga_mgr_free(struct fpga_manager *mgr) > >>> -{ > >>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id); > >>> -    kfree(mgr); > >>> -} > >>> -EXPORT_SYMBOL_GPL(fpga_mgr_free); > >>> - > >>> -static void devm_fpga_mgr_release(struct device *dev, void *res) > >>> -{ > >>> -    struct fpga_mgr_devres *dr = res; > >>> - > >>> -    fpga_mgr_free(dr->mgr); > >>> -} > >>> - > >>> -/** > >>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct > >>> - * @dev:    fpga manager device from pdev > >>> - * @name:    fpga manager name > >>> - * @mops:    pointer to structure of fpga manager ops > >>> - * @priv:    fpga manager private data > >>> - * > >>> - * This function is intended for use in a FPGA manager driver's probe function. > >>> - * After the manager driver creates the manager struct with > >>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The > >>> - * manager driver's remove function should call fpga_mgr_unregister().  The > >>> - * manager struct allocated with this function will be freed automatically on > >>> - * driver detach.  This includes the case of a probe function returning error > >>> - * before calling fpga_mgr_register(), the struct will still get cleaned up. > >>> - * > >>> - * Return: pointer to struct fpga_manager or NULL > >>> - */ > >>> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name, > >>> -                      const struct fpga_manager_ops *mops, > >>> -                      void *priv) > >>> -{ > >>> -    struct fpga_mgr_devres *dr; > >>> - > >>> -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL); > >>> -    if (!dr) > >>> -        return NULL; > >>> - > >>> -    dr->mgr = fpga_mgr_create(dev, name, mops, priv); > >>> -    if (!dr->mgr) { > >>> -        devres_free(dr); > >>> -        return NULL; > >>> -    } > >>> - > >>> -    devres_add(dev, dr); > >>> - > >>> -    return dr->mgr; > >>> -} > >>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create); > >>> - > >>> -/** > >>> - * fpga_mgr_register - register a FPGA manager > >>> - * @mgr: fpga manager struct > >>> - * > >>> - * Return: 0 on success, negative error code otherwise. > >>> - */ > >>> -int fpga_mgr_register(struct fpga_manager *mgr) > >>> -{ > >>> -    int ret; > >>> - > >>>       /* > >>>        * Initialize framework state by requesting low level driver read state > >>>        * from device.  FPGA may be in reset mode or may have been programmed > >>> @@ -690,18 +616,20 @@ int fpga_mgr_register(struct fpga_manager *mgr) > >>>        */ > >>>       mgr->state = mgr->mops->state(mgr); > >>>   -    ret = device_add(&mgr->dev); > >>> -    if (ret) > >>> -        goto error_device; > >>> - > >>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name); > >> can we keep this dev_info() line and move it below device_register() ? > > In Greg's response to my driver, he said he said that a well-behaved driver does > > not need dev_info() calls... > >>> +    ret = device_register(&mgr->dev); > >>> +    if (ret) { > >>> +        put_device(&mgr->dev); > >> pr_err() here ? > > OK - I can add a message > > > >>> +        return ERR_PTR(ret); > >>> +    } > >>>   -    return 0; > >>> +    return mgr; > >>>     error_device: > >>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id); > >>> +    ida_simple_remove(&fpga_mgr_ida, id); > >>> +error_kfree: > >>> +    kfree(mgr); > >>>   -    return ret; > >>> +    return ERR_PTR(ret); > >>>   } > >>>   EXPORT_SYMBOL_GPL(fpga_mgr_register); > >>>   @@ -726,14 +654,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr) > >>>   } > >>>   EXPORT_SYMBOL_GPL(fpga_mgr_unregister); > >>>   -static int fpga_mgr_devres_match(struct device *dev, void *res, > >>> -                 void *match_data) > >>> -{ > >>> -    struct fpga_mgr_devres *dr = res; > >>> - > >>> -    return match_data == dr->mgr; > >>> -} > >>> - > >>>   static void devm_fpga_mgr_unregister(struct device *dev, void *res) > >>>   { > >>>       struct fpga_mgr_devres *dr = res; > >>> @@ -743,44 +663,46 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res) > >>>     /** > >>>    * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register() > >>> - * @dev: managing device for this FPGA manager > >>> - * @mgr: fpga manager struct > >>> + * @dev:    fpga manager device from pdev > >>> + * @name:    fpga manager name > >>> + * @compat_id:    FPGA manager id for compatibility check. > >>> + * @mops:    pointer to structure of fpga manager ops > >>> + * @priv:    fpga manager private data > >>>    * > >>>    * This is the devres variant of fpga_mgr_register() for which the unregister > >>>    * function will be called automatically when the managing device is detached. > >>>    */ > >>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr) > >>> +struct fpga_manager * > >>> +devm_fpga_mgr_register(struct device *dev, const char *name, > >>> +               struct fpga_compat_id *compat_id, > >>> +               const struct fpga_manager_ops *mops, void *priv) > >>>   { > >>>       struct fpga_mgr_devres *dr; > >>> -    int ret; > >>> - > >>> -    /* > >>> -     * Make sure that the struct fpga_manager * that is passed in is > >>> -     * managed itself. > >>> -     */ > >>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release, > >>> -                 fpga_mgr_devres_match, mgr))) > >>> -        return -EINVAL; > >>> +    struct fpga_manager *mgr; > >>>         dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL); > >>>       if (!dr) > >>> -        return -ENOMEM; > >>> +        return ERR_PTR(-ENOMEM); > >>>   -    ret = fpga_mgr_register(mgr); > >>> -    if (ret) { > >>> +    mgr = fpga_mgr_register(dev, name, compat_id, mops, priv); > >>> +    if (IS_ERR(mgr)) { > >>>           devres_free(dr); > >>> -        return ret; > >>> +        return mgr; > >>>       } > >>>         dr->mgr = mgr; > >>>       devres_add(dev, dr); > >>>   -    return 0; > >>> +    return mgr; > >>>   } > >>>   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register); > >>>     static void fpga_mgr_dev_release(struct device *dev) > >>>   { > >>> +    struct fpga_manager *mgr = to_fpga_manager(dev); > >>> + > >>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id); > >>> +    kfree(mgr); > >>>   } > >>>     static int __init fpga_mgr_class_init(void) > >>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c > >>> index 69dec5af23c3..b1c7c0713e11 100644 > >>> --- a/drivers/fpga/ice40-spi.c > >>> +++ b/drivers/fpga/ice40-spi.c > >>> @@ -178,12 +178,12 @@ static int ice40_fpga_probe(struct spi_device *spi) > >>>           return ret; > >>>       } > >>>   -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager", > >>> -                   &ice40_fpga_ops, priv); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager", > >>> +                     NULL, &ice40_fpga_ops, priv); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(dev, mgr); > >>> +    return 0; > >>>   } > >>>     static const struct of_device_id ice40_fpga_of_match[] = { > >>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c > >>> index 114a64d2b7a4..75cc6efaa1b6 100644 > >>> --- a/drivers/fpga/machxo2-spi.c > >>> +++ b/drivers/fpga/machxo2-spi.c > >>> @@ -366,12 +366,12 @@ static int machxo2_spi_probe(struct spi_device *spi) > >>>           return -EINVAL; > >>>       } > >>>   -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager", > >>> -                   &machxo2_ops, spi); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager", > >>> +                     NULL, &machxo2_ops, spi); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(dev, mgr); > >>> +    return 0; > >>>   } > >>>     static const struct of_device_id of_match[] = { > >>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c > >>> index 573d88bdf730..80b8891fb302 100644 > >>> --- a/drivers/fpga/socfpga-a10.c > >>> +++ b/drivers/fpga/socfpga-a10.c > >>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev) > >>>           return -EBUSY; > >>>       } > >>>   -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager", > >>> -                   &socfpga_a10_fpga_mgr_ops, priv); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> - > >>> -    platform_set_drvdata(pdev, mgr); > >>> - > >>> -    ret = fpga_mgr_register(mgr); > >>> -    if (ret) { > >>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager", > >>> +                NULL, &socfpga_a10_fpga_mgr_ops, priv); > >>> +    if (IS_ERR(mgr)) { > >>>           clk_disable_unprepare(priv->clk); > >>> -        return ret; > >>> +        return PTR_ERR(mgr); > >>>       } > >>>   +    platform_set_drvdata(pdev, mgr); > >>> + > >>>       return 0; > >>>   } > >>>   diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c > >>> index 1f467173fc1f..06edfab8a496 100644 > >>> --- a/drivers/fpga/socfpga.c > >>> +++ b/drivers/fpga/socfpga.c > >>> @@ -571,12 +571,12 @@ static int socfpga_fpga_probe(struct platform_device *pdev) > >>>       if (ret) > >>>           return ret; > >>>   -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager", > >>> -                   &socfpga_fpga_ops, priv); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager", > >>> +                     NULL, &socfpga_fpga_ops, priv); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(dev, mgr); > >>> +    return 0; > >>>   } > >>>     #ifdef CONFIG_OF > >>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c > >>> index 657a70c5fc99..434094c3ac69 100644 > >>> --- a/drivers/fpga/stratix10-soc.c > >>> +++ b/drivers/fpga/stratix10-soc.c > >>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev) > >>>         init_completion(&priv->status_return_completion); > >>>   -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager", > >>> -                  &s10_ops, priv); > >>> -    if (!mgr) { > >>> -        dev_err(dev, "unable to create FPGA manager\n"); > >>> -        ret = -ENOMEM; > >>> -        goto probe_err; > >>> -    } > >>> - > >>> -    ret = fpga_mgr_register(mgr); > >>> -    if (ret) { > >>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager", > >>> +                NULL, &s10_ops, priv); > >>> +    if (IS_ERR(mgr)) { > >>>           dev_err(dev, "unable to register FPGA manager\n"); > >>> -        fpga_mgr_free(mgr); > >>> +        ret = PTR_ERR(mgr); > >>>           goto probe_err; > >>>       } > >>>   diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c > >>> index 101f016c6ed8..5efbec2b9f9f 100644 > >>> --- a/drivers/fpga/ts73xx-fpga.c > >>> +++ b/drivers/fpga/ts73xx-fpga.c > >>> @@ -122,12 +122,12 @@ static int ts73xx_fpga_probe(struct platform_device *pdev) > >>>       if (IS_ERR(priv->io_base)) > >>>           return PTR_ERR(priv->io_base); > >>>   -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager", > >>> -                   &ts73xx_fpga_ops, priv); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager", > >> This is missing compat_id param. > > Thanks - I thought I'll do another pass and make sure I catch them all. > > > >> Similar for others. > >> > >>> +                     &ts73xx_fpga_ops, priv); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(kdev, mgr); > >>> +    return 0; > >>>   } > >>>     static struct platform_driver ts73xx_fpga_driver = { > >>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c > >>> index fee4d0abf6bf..6f1894929687 100644 > >>> --- a/drivers/fpga/xilinx-spi.c > >>> +++ b/drivers/fpga/xilinx-spi.c > >>> @@ -247,13 +247,13 @@ static int xilinx_spi_probe(struct spi_device *spi) > >>>           return dev_err_probe(&spi->dev, PTR_ERR(conf->done), > >>>                        "Failed to get DONE gpio\n"); > >>>   -    mgr = devm_fpga_mgr_create(&spi->dev, > >>> -                   "Xilinx Slave Serial FPGA Manager", > >>> -                   &xilinx_spi_ops, conf); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> +    mgr = devm_fpga_mgr_register(&spi->dev, > >>> +                     "Xilinx Slave Serial FPGA Manager", > >>> +                     NULL, &xilinx_spi_ops, conf); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(&spi->dev, mgr); > >>> +    return 0; > >>>   } > >>>     static const struct of_device_id xlnx_spi_of_match[] = { > >>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c > >>> index 07fa8d9ec675..74bbb9710f4e 100644 > >>> --- a/drivers/fpga/zynq-fpga.c > >>> +++ b/drivers/fpga/zynq-fpga.c > >>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev) > >>>         clk_disable(priv->clk); > >>>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager", > >>> -                   &zynq_fpga_ops, priv); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> - > >>> -    platform_set_drvdata(pdev, mgr); > >>> - > >>> -    err = fpga_mgr_register(mgr); > >>> -    if (err) { > >>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager", > >> This is missing compat_id param as well. > >>> +                &zynq_fpga_ops, priv); > >>> +    if (IS_ERR(mgr)) { > >>>           dev_err(dev, "unable to register FPGA manager\n"); > >>>           clk_unprepare(priv->clk); > >>> -        return err; > >>> +        return PTR_ERR(mgr); > >>>       } > >>>   +    platform_set_drvdata(pdev, mgr); > >>> + > >>>       return 0; > >>>   } > >>>   diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c > >>> index 125743c9797f..1a6d520985be 100644 > >>> --- a/drivers/fpga/zynqmp-fpga.c > >>> +++ b/drivers/fpga/zynqmp-fpga.c > >>> @@ -102,12 +102,12 @@ static int zynqmp_fpga_probe(struct platform_device *pdev) > >>>         priv->dev = dev; > >>>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager", > >>> -                   &zynqmp_fpga_ops, priv); > >>> -    if (!mgr) > >>> -        return -ENOMEM; > >>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager", > >>> +                     &zynqmp_fpga_ops, priv); > >>> +    if (IS_ERR(mgr)) > >>> +        return PTR_ERR(mgr); > >>>   -    return devm_fpga_mgr_register(dev, mgr); > >>> +    return 0; > >>>   } > >>>     static const struct of_device_id zynqmp_fpga_of_match[] = { > >>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h > >>> index 2bc3030a69e5..3e1859cc0640 100644 > >>> --- a/include/linux/fpga/fpga-mgr.h > >>> +++ b/include/linux/fpga/fpga-mgr.h > >>> @@ -191,17 +191,16 @@ struct fpga_manager *fpga_mgr_get(struct device *dev); > >>>     void fpga_mgr_put(struct fpga_manager *mgr); > >>>   -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name, > >>> -                     const struct fpga_manager_ops *mops, > >>> -                     void *priv); > >> My biggest concern is that removing this will break all oot fpga drivers. > >> > >> The other patches have similar api changes > >> > >> Having a stable api is very important. > > That is a good point. While Greg did call out the separation of the > > device_initialize() and device_add() calls, his biggest concern was with > > the empty dev_release() functions. Maybe it would be best to first submit > > a patch that only addresses the dev_release() functions? Maybe it would be > > OK to leave the create and register functions as separate functions in order > > to maintain a stable API... > > On further investigation, I don't think we have much choice in changing > the API. We are almost coming full circle here. In 2018, there was only > an fpga_mgr_register() function. It was returning an errno value or zero. > It was also setting the drvdata of the parent driver with a pointer to > the resulting fpga_manager structure. > > It looks like the reason the interface was split into two (create and > register) was so that the fpga_manager pointer could be returned (by the > create function) without writing the drvdata of the parent driver: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7085e2a94f7df5f419e3cfb2fe809ce6564e9629 > > When the interfaces were split, fpga_mgr_free() was also created to free > the memory if the register function was not called. The fpga_mgr_free() > function was also called by the fpga_mgr_dev_release() function. A later > patch was submitted to simplify the memory management for the class driver: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=084181fe8cc7472695b907f0018f4cd00934cb12 > > It is this second commit that empties the fpga_mgr_dev_release() function > and instead uses devm_fpga_mgr_create() to manage the memory for the class > driver. > > The fix I am proposing essentially takes us back to the 2018 implementation, > but returns the fpga_manager pointer or ERR_PTR() instead of returning zero or > an errno. > > The definition of the API is integral to the memory management issue. I cannot > think of an acceptable solution for the upstream that doesn't involve > changing the API. It could result in some ifdef's in an out-of-tree driver, > but I don't think we can avoid it in this case. I agree the stable API is important, and I think it is still possible to fix the memory management issue while keeping the APIs. We should do the actual resource free work in class.dev_release(), and fpga_mgr_free should call put_device() to trigger it. And I see no problem with the current devm APIs. Thanks, Yilun > > > - Russ > > > >> My recommendation is to keep the public api and hide the change with an exported but not public function. > >> > >> Tom > >> > >>> -void fpga_mgr_free(struct fpga_manager *mgr); > >>> -int fpga_mgr_register(struct fpga_manager *mgr); > >>> +struct fpga_manager *fpga_mgr_register(struct device *dev, const char *name, > >>> +                       struct fpga_compat_id *compat_id, > >>> +                       const struct fpga_manager_ops *mops, > >>> +                       void *priv); > >>>   void fpga_mgr_unregister(struct fpga_manager *mgr); > >>>   -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr); > >>> - > >>> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name, > >>> -                      const struct fpga_manager_ops *mops, > >>> -                      void *priv); > >>> +struct fpga_manager * > >>> +devm_fpga_mgr_register(struct device *dev, const char *name, > >>> +               struct fpga_compat_id *compat_id, > >>> +               const struct fpga_manager_ops *mops, > >>> +               void *priv); > >>>     #endif /*_LINUX_FPGA_MGR_H */