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=-20.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 72E71C47094 for ; Mon, 7 Jun 2021 23:51:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E89860E0B for ; Mon, 7 Jun 2021 23:51:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230239AbhFGXw5 (ORCPT ); Mon, 7 Jun 2021 19:52:57 -0400 Received: from mga05.intel.com ([192.55.52.43]:48815 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230251AbhFGXw4 (ORCPT ); Mon, 7 Jun 2021 19:52:56 -0400 IronPort-SDR: 8U5TQecRe2usJNUMbM76HSiODWPirUbvsz88XbAOL9gxKgApuYjXQjsb+BNozm0KNnRUtSGvA8 76dSHU1JTMjA== X-IronPort-AV: E=McAfee;i="6200,9189,10008"; a="290368171" X-IronPort-AV: E=Sophos;i="5.83,256,1616482800"; d="scan'208";a="290368171" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2021 16:51:04 -0700 IronPort-SDR: 70xKpDmu39/VY8SCJi5zJFoqduH4Wg9iFBiS14Uw2yGgm2NcFU9KyBczq6lGe+VZOMCFcI55FK zVgYHv1nmHmQ== X-IronPort-AV: E=Sophos;i="5.83,256,1616482800"; d="scan'208";a="401859424" Received: from rhweight-mobl2.amr.corp.intel.com (HELO [10.0.2.4]) ([10.209.120.106]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2021 16:51:03 -0700 Subject: Re: [PATCH v4 1/3] fpga: mgr: Use standard dev_release for class driver To: Xu Yilun 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 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> <20210605154253.GA1973240@yilunxu-OptiPlex-7050> From: Russ Weight Message-ID: <6ba648a9-0722-856d-0a4f-a2b8eba68355@intel.com> Date: Mon, 7 Jun 2021 16:50:58 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210605154253.GA1973240@yilunxu-OptiPlex-7050> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org On 6/5/21 8:42 AM, Xu Yilun wrote: > 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. Consider the case where both devm_fpga_mgr_create() and devm_fpga_mgr_register() are called, and both succeed. When the driver is unloaded devm_fpga_mgr_release() is called on behalf of the create and it will call put_device(). Then devm_fpga_mgr_unregister() will be called on behalf of the register, and it will call device_unregister(), which also calls put_device(). In this case, I think there is an extra call to put_device(), right? Or is that not a problem? The only way I can think to avoid the extra put_device() call for this case would be to set a flag when-and-if fpga_mgr_register() succeeds and then refuse to call put_device() in devm_fpga_mgr_release() in order to avoid the duplicate call to put_device(). But that feels like a hack to me. Am I missing something? Is there a cleaner way to make this work? - Russ > > 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 */