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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 7ED6DC07E96 for ; Tue, 6 Jul 2021 21:02:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6331F61CA6 for ; Tue, 6 Jul 2021 21:02:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229807AbhGFVFN (ORCPT ); Tue, 6 Jul 2021 17:05:13 -0400 Received: from mga14.intel.com ([192.55.52.115]:44971 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230197AbhGFVFN (ORCPT ); Tue, 6 Jul 2021 17:05:13 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10037"; a="209013559" X-IronPort-AV: E=Sophos;i="5.83,329,1616482800"; d="scan'208";a="209013559" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2021 14:02:33 -0700 X-IronPort-AV: E=Sophos;i="5.83,329,1616482800"; d="scan'208";a="457207606" Received: from rhweight-mobl2.amr.corp.intel.com (HELO [10.0.2.4]) ([10.209.123.96]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2021 14:02:32 -0700 Subject: Re: [PATCH v9 1/3] fpga: mgr: Use standard dev_release for class driver To: Tom Rix , mdf@kernel.org, linux-fpga@vger.kernel.org Cc: lgoncalv@redhat.com, yilun.xu@intel.com, hao.wu@intel.com, matthew.gerlach@intel.com, richard.gong@intel.com References: <20210701013733.75483-1-russell.h.weight@intel.com> <20210701013733.75483-2-russell.h.weight@intel.com> From: Russ Weight Message-ID: Date: Tue, 6 Jul 2021 14:02:20 -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: 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 7/6/21 12:04 PM, Tom Rix wrote: > Russ, > > My two big concerns are. > > compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv. fpga_mgr_info is a temporary structure on the stack that contains the parameters only long enough to pass them in and have them added to the fpga_manager structure. Do you have a concern about it being on the fpga_manager structure. > > there are two register functions, there should be one. I get what you are saying. I don't really like the idea of forcing the complexity of the temporary structure on all callers, since only a couple require it, but we can do that if that is the concensus. What do others think? > > On 6/30/21 6:37 PM, Russ Weight wrote: >> The FPGA manager class driver data structure is being treated as a >> managed resource instead of using the standard dev_release call-back >> function 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() or register_simple() function. >> >> The register() function accepts an info data structure to provide >> flexibility in passing optional parameters. The register_simple() >> function supports the current parameter list for users that don't >> require the use of optional parameters. >> >> The devm_fpga_mgr_register() function is retained, and the >> devm_fpga_mgr_register_simple() function is added. >> >> Signed-off-by: Russ Weight >> Reviewed-by: Xu Yilun >> --- >> v9: >>    - Cleaned up documentation for the FPGA Manager register functions >>    - Renamed fpga_mgr_register() to fpga_mgr_register_full() >>    - Renamed fpga_mgr_register_simple() to fpga_mgr_register() >>    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full() >>    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register() >> v8: >>    - Added reviewed-by tag. >>    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation. >> v7: >>    - Update the commit message to describe the new parameters for the >>      *fpga_mgr_register() functions and to mention the >>      *fpga_mgr_register_simple() functions. >>    - Fix function prototypes in header file to rename dev to parent. >>    - Make use of the PTR_ERR_OR_ZERO() macro when possible. >>    - Some cleanup of comments. >>    - Update function defintions/prototypes to apply const to the new info >>      parameter. >> v6: >>    - Moved FPGA manager optional parameters out of the ops structure and >>      back into the FPGA manager structure. >>    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to >>      accept an info data structure to provide flexibility in passing optional >>      parameters. >>    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple() >>      functions to support current parameters for users that don't require >>      the use of optional parameters. >> v5: >>    - Rebased on top of recently accepted patches. >>    - Removed compat_id from the fpga_mgr_register() parameter list >>      and added it to the fpga_manager_ops structure. This also required >>      dynamically allocating the dfl-fme-ops structure in order to add >>      the appropriate compat_id. >> v4: >>    - Added the compat_id parameter to fpga_mgr_register() and >>      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. >> --- >>   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++- >>   drivers/fpga/altera-cvp.c                  |  12 +- >>   drivers/fpga/altera-pr-ip-core.c           |   7 +- >>   drivers/fpga/altera-ps-spi.c               |   9 +- >>   drivers/fpga/dfl-fme-mgr.c                 |  22 +-- >>   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------ >>   drivers/fpga/ice40-spi.c                   |   9 +- >>   drivers/fpga/machxo2-spi.c                 |   9 +- >>   drivers/fpga/socfpga-a10.c                 |  16 +- >>   drivers/fpga/socfpga.c                     |   9 +- >>   drivers/fpga/stratix10-soc.c               |  16 +- >>   drivers/fpga/ts73xx-fpga.c                 |   9 +- >>   drivers/fpga/xilinx-spi.c                  |  11 +- >>   drivers/fpga/zynq-fpga.c                   |  16 +- >>   drivers/fpga/zynqmp-fpga.c                 |   9 +- >>   include/linux/fpga/fpga-mgr.h              |  62 ++++-- >>   16 files changed, 210 insertions(+), 255 deletions(-) >> >> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst >> index 4d926b452cb3..826ed8dc9210 100644 >> --- a/Documentation/driver-api/fpga/fpga-mgr.rst >> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst >> @@ -24,7 +24,7 @@ How to support a new FPGA device >>   -------------------------------- >>     To add another FPGA manager, write a driver that implements a set of ops.  The >> -probe function calls fpga_mgr_register(), such as:: >> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as:: >>         static const struct fpga_manager_ops socfpga_fpga_ops = { >>           .write_init = socfpga_fpga_ops_configure_init, >> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as:: >>            * them in priv >>            */ >>   -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager", >> -                       &socfpga_fpga_ops, priv); >> -        if (!mgr) >> -            return -ENOMEM; >> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager", >> +                    &socfpga_fpga_ops, priv); >> +        if (IS_ERR(mgr)) >> +            return PTR_ERR(mgr); >>             platform_set_drvdata(pdev, mgr); >>   -        return fpga_mgr_register(mgr); >> +        return 0; >>       } >>         static int socfpga_fpga_remove(struct platform_device *pdev) >> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as:: >>           return 0; >>       } >>   +Alternatively, the probe function could call one of the resource managed >> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full(). >> +When these functions are used, the parameter syntax is the same, but the call >> +to fpga_mgr_unregister() should be removed. In the above example, the >> +socfpga_fpga_remove() function would not be required. >>     The ops will implement whatever device specific register writes are needed to >>   do the programming sequence for this particular FPGA.  These ops return 0 for >> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver >>   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`. >>   * struct fpga_manager -  the FPGA manager struct >>   * struct fpga_manager_ops -  Low level FPGA manager driver ops >> -* devm_fpga_mgr_create() -  Allocate and init a manager struct >> -* fpga_mgr_register() -  Register an FPGA manager >> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the >> +  fpga_mgr_info structure to provide the full flexibility of options >> +* fpga_mgr_register() -  Create and register an FPGA manager using standard >> +  arguments >> +* devm_fpga_mgr_register_full() -  Resource managed version of >> +  fpga_mgr_register_full() >> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register() >>   * fpga_mgr_unregister() -  Unregister an FPGA manager >>     .. kernel-doc:: include/linux/fpga/fpga-mgr.h >> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver >>      :functions: fpga_manager_ops >>     .. kernel-doc:: drivers/fpga/fpga-mgr.c >> -   :functions: devm_fpga_mgr_create >> +   :functions: fpga_mgr_register_full >>     .. kernel-doc:: drivers/fpga/fpga-mgr.c >>      :functions: fpga_mgr_register >>   +.. kernel-doc:: drivers/fpga/fpga-mgr.c >> +   :functions: devm_fpga_mgr_register_full >> + >> +.. kernel-doc:: drivers/fpga/fpga-mgr.c >> +   :functions: devm_fpga_mgr_register >> + >>   .. kernel-doc:: drivers/fpga/fpga-mgr.c >>      :functions: fpga_mgr_unregister >> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c >> index ccf4546eff29..4ffb9da537d8 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, >> +                &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 dfdf21ed34c4..be0667968d33 100644 >> --- a/drivers/fpga/altera-pr-ip-core.c >> +++ b/drivers/fpga/altera-pr-ip-core.c >> @@ -191,11 +191,8 @@ 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; >> - >> -    return devm_fpga_mgr_register(dev, mgr); >> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>   EXPORT_SYMBOL_GPL(alt_pr_register); >>   diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c >> index 23bfd4d1ad0f..5e1e009dba89 100644 >> --- a/drivers/fpga/altera-ps-spi.c >> +++ b/drivers/fpga/altera-ps-spi.c >> @@ -302,12 +302,9 @@ 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; >> - >> -    return devm_fpga_mgr_register(&spi->dev, mgr); >> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name, >> +                     &altera_ps_ops, conf); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>     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..620e7874ab53 100644 >> --- a/drivers/fpga/dfl-fme-mgr.c >> +++ b/drivers/fpga/dfl-fme-mgr.c >> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr, >>   static int fme_mgr_probe(struct platform_device *pdev) >>   { >>       struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev); >> -    struct fpga_compat_id *compat_id; >> +    struct fpga_manager_info info = { 0 }; >>       struct device *dev = &pdev->dev; >>       struct fme_mgr_priv *priv; >>       struct fpga_manager *mgr; >> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev) >>               return PTR_ERR(priv->ioaddr); >>       } >>   -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL); >> -    if (!compat_id) >> +    info.name = "DFL FME FPGA Manager"; >> +    info.mops = &fme_mgr_ops; >> +    info.priv = priv; >> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL); >> +    if (!info.compat_id) >>           return -ENOMEM; > could we limp along instead of failing ? The compat_id is used to verify compatibility between the static region and the partial reconfiguration. If there is insufficient memory for the small data structure, I think it is best to fail here. This is also consistent current implementation.   >>   -    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; >> - >> -    return devm_fpga_mgr_register(dev, mgr); >> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id); >> +    mgr = devm_fpga_mgr_register_full(dev, &info); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>     static struct platform_driver fme_mgr_driver = { >> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c >> index ecb4c3c795fa..5a913aa649fd 100644 >> --- a/drivers/fpga/fpga-mgr.c >> +++ b/drivers/fpga/fpga-mgr.c >> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr) >>   EXPORT_SYMBOL_GPL(fpga_mgr_unlock); >>     /** >> - * fpga_mgr_create - create and initialize an FPGA manager struct >> + * fpga_mgr_register_full - create and register an FPGA Manager device >>    * @parent:    fpga manager device from pdev >> - * @name:    fpga manager name >> - * @mops:    pointer to structure of fpga manager ops >> - * @priv:    fpga manager private data >> + * @info:    parameters for fpga manager >>    * >> - * 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_full() instead is recommended. >>    * >> - * Return: pointer to struct fpga_manager or NULL >> + * Return: pointer to struct fpga_manager pointer or ERR_PTR() >>    */ >> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name, >> -                     const struct fpga_manager_ops *mops, >> -                     void *priv) >> +struct fpga_manager * >> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info) >>   { >> +    const struct fpga_manager_ops *mops = info->mops; >>       struct fpga_manager *mgr; >>       int id, ret; >>   @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name, >>           !mops->write_init || (!mops->write && !mops->write_sg) || >>           (mops->write && mops->write_sg)) { >>           dev_err(parent, "Attempt to register without fpga_manager_ops\n"); >> -        return NULL; >> +        return ERR_PTR(-EINVAL); >>       } >>   -    if (!name || !strlen(name)) { >> +    if (!info->name || !strlen(info->name)) { >>           dev_err(parent, "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; >>           goto error_kfree; >> +    } >>         mutex_init(&mgr->ref_mutex); >>   -    mgr->name = name; >> -    mgr->mops = mops; >> -    mgr->priv = priv; >> +    mgr->name = info->name; >> +    mgr->mops = info->mops; >> +    mgr->priv = info->priv; >> +    mgr->compat_id = info->compat_id; >>   -    device_initialize(&mgr->dev); >>       mgr->dev.class = fpga_mgr_class; >>       mgr->dev.groups = mops->groups; >>       mgr->dev.parent = parent; >> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name, >>       if (ret) >>           goto error_device; >>   +    /* >> +     * Initialize framework state by requesting low level driver read state >> +     * from device.  FPGA may be in reset mode or may have been programmed >> +     * by bootloader or EEPROM. >> +     */ >> +    mgr->state = mgr->mops->state(mgr); > > This is existing code, but it seems wrong. > > A side effect of state() should not be to initialize. > > An init() should be added to mops I think this is just capturing the state of the underlying device an reflecting it in the fpga-manager state? Maybe someone else can comment on this. It seems outside the scope of these patches. > >> + >> +    ret = device_register(&mgr->dev); >> +    if (ret) { >> +        put_device(&mgr->dev); >> +        return ERR_PTR(ret); >> +    } >> + >>       return mgr; >>     error_device: >> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name, >>   error_kfree: >>       kfree(mgr); >>   -    return NULL; >> +    return ERR_PTR(ret); >>   } >> -EXPORT_SYMBOL_GPL(fpga_mgr_create); >> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full); >>     /** >> - * fpga_mgr_free - free an 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 >> + * fpga_mgr_register - create and register an FPGA Manager device >>    * @parent:    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 an 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. >> + * The caller of this function is responsible for calling fpga_mgr_unregister(). >> + * Using devm_fpga_mgr_register() instead is recommended. This simple >> + * version of the register function should be sufficient for most users. The >> + * fpga_mgr_register_full() function is available for users that need to pass >> + * additional, optional parameters. >>    * >> - * Return: pointer to struct fpga_manager or NULL >> + * Return: pointer to struct fpga_manager pointer or ERR_PTR() >>    */ >> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name, >> -                      const struct fpga_manager_ops *mops, >> -                      void *priv) >> +struct fpga_manager * >> +fpga_mgr_register(struct device *parent, const char *name, >> +          const struct fpga_manager_ops *mops, void *priv) >>   { >> -    struct fpga_mgr_devres *dr; >> +    struct fpga_manager_info info = { 0 }; >>   -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL); >> -    if (!dr) >> -        return NULL; >> +    info.name = name; >> +    info.mops = mops; >> +    info.priv = priv; >>   -    dr->mgr = fpga_mgr_create(parent, name, mops, priv); >> -    if (!dr->mgr) { >> -        devres_free(dr); >> -        return NULL; >> -    } >> - >> -    devres_add(parent, dr); >> - >> -    return dr->mgr; >> -} >> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create); >> - >> -/** >> - * fpga_mgr_register - register an 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 >> -     * by bootloader or EEPROM. >> -     */ >> -    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); >> - >> -    return 0; >> - >> -error_device: >> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id); >> - >> -    return ret; >> +    return fpga_mgr_register_full(parent, &info); >>   } >>   EXPORT_SYMBOL_GPL(fpga_mgr_register); >>   @@ -726,14 +679,6 @@ 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; >> @@ -742,45 +687,67 @@ 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 >> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register() >> + * @parent:    fpga manager device from pdev >> + * @info:    parameters for fpga manager >>    * >> - * This is the devres variant of fpga_mgr_register() for which the unregister >> + * This is the devres variant of fpga_mgr_register_full() 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_full(struct device *parent, const struct fpga_manager_info *info) >>   { >>       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_full(parent, info); >> +    if (IS_ERR(mgr)) { >>           devres_free(dr); >> -        return ret; >> +        return mgr; >>       } >>         dr->mgr = mgr; >> -    devres_add(dev, dr); >> +    devres_add(parent, dr); >>   -    return 0; >> +    return mgr; >> +} >> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full); >> + >> +/** >> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register() >> + * @parent:    fpga manager device from pdev >> + * @name:    fpga manager name >> + * @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. >> + */ >> +struct fpga_manager * >> +devm_fpga_mgr_register(struct device *parent, const char *name, >> +               const struct fpga_manager_ops *mops, void *priv) >> +{ >> +    struct fpga_manager_info info = { 0 }; >> + >> +    info.name = name; >> +    info.mops = mops; >> +    info.priv = priv; >> + >> +    return devm_fpga_mgr_register_full(parent, &info); >>   } >>   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..b7591912248f 100644 >> --- a/drivers/fpga/ice40-spi.c >> +++ b/drivers/fpga/ice40-spi.c >> @@ -178,12 +178,9 @@ 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; >> - >> -    return devm_fpga_mgr_register(dev, mgr); >> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager", >> +                     &ice40_fpga_ops, priv); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>     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 1afb41aa20d7..8469dfb5dd21 100644 >> --- a/drivers/fpga/machxo2-spi.c >> +++ b/drivers/fpga/machxo2-spi.c >> @@ -366,12 +366,9 @@ 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; >> - >> -    return devm_fpga_mgr_register(dev, mgr); >> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager", >> +                     &machxo2_ops, spi); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>     #ifdef CONFIG_OF >> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c >> index 573d88bdf730..ac8e89b8a5cc 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", >> +                &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..7e0741f99696 100644 >> --- a/drivers/fpga/socfpga.c >> +++ b/drivers/fpga/socfpga.c >> @@ -571,12 +571,9 @@ 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; >> - >> -    return devm_fpga_mgr_register(dev, mgr); >> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager", >> +                     &socfpga_fpga_ops, priv); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>     #ifdef CONFIG_OF >> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c >> index a2cea500f7cc..9155e888a133 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", >> +                &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; >>       } >>   @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev) >>       struct s10_priv *priv = mgr->priv; >>         fpga_mgr_unregister(mgr); >> -    fpga_mgr_free(mgr); >>       stratix10_svc_free_channel(priv->chan); >>         return 0; >> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c >> index 101f016c6ed8..fd52de20ddb2 100644 >> --- a/drivers/fpga/ts73xx-fpga.c >> +++ b/drivers/fpga/ts73xx-fpga.c >> @@ -122,12 +122,9 @@ 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; >> - >> -    return devm_fpga_mgr_register(kdev, mgr); >> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager", >> +                     &ts73xx_fpga_ops, priv); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>     static struct platform_driver ts73xx_fpga_driver = { >> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c >> index fee4d0abf6bf..db23626f9ab2 100644 >> --- a/drivers/fpga/xilinx-spi.c >> +++ b/drivers/fpga/xilinx-spi.c >> @@ -247,13 +247,10 @@ 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; >> - >> -    return devm_fpga_mgr_register(&spi->dev, mgr); >> +    mgr = devm_fpga_mgr_register(&spi->dev, >> +                     "Xilinx Slave Serial FPGA Manager", >> +                     &xilinx_spi_ops, conf); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>     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 9b75bd4f93d8..426aa34c6a0d 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", >> +                &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..975bdc4d0a65 100644 >> --- a/drivers/fpga/zynqmp-fpga.c >> +++ b/drivers/fpga/zynqmp-fpga.c >> @@ -102,12 +102,9 @@ 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; >> - >> -    return devm_fpga_mgr_register(dev, mgr); >> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager", >> +                     &zynqmp_fpga_ops, priv); >> +    return PTR_ERR_OR_ZERO(mgr); >>   } >>     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 474c1f506307..ac3ddaf2903c 100644 >> --- a/include/linux/fpga/fpga-mgr.h >> +++ b/include/linux/fpga/fpga-mgr.h >> @@ -105,6 +105,36 @@ struct fpga_image_info { >>   #endif >>   }; >>   +/** >> + * struct fpga_compat_id - id for compatibility check >> + * >> + * @id_h: high 64bit of the compat_id >> + * @id_l: low 64bit of the compat_id >> + */ >> +struct fpga_compat_id { >> +    u64 id_h; >> +    u64 id_l; >> +}; >> + > > There are two register functions are to handle this dfl only structure. > > This really needs to be moved fme_mgr_priv. > >> +/** >> + * struct fpga_manager_info - collection of parameters for an FPGA Manager >> + * @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 >> + * >> + * fpga_manager_info contains parameters for the register function. These >> + * are separated into an info structure because they some are optional >> + * others could be added to in the future. The info structure facilitates >> + * maintaining a stable API. >> + */ >> +struct fpga_manager_info { >> +    const char *name; >> +    struct fpga_compat_id *compat_id; >> +    const struct fpga_manager_ops *mops; >> +    void *priv; >> +}; >> + >>   /** >>    * struct fpga_manager_ops - ops for low level fpga manager drivers >>    * @initial_header_size: Maximum number of bytes that should be passed into write_init >> @@ -143,17 +173,6 @@ struct fpga_manager_ops { >>   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3) >>   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4) >>   -/** >> - * struct fpga_compat_id - id for compatibility check >> - * >> - * @id_h: high 64bit of the compat_id >> - * @id_l: low 64bit of the compat_id >> - */ >> -struct fpga_compat_id { >> -    u64 id_h; >> -    u64 id_l; >> -}; >> - >>   /** >>    * struct fpga_manager - fpga manager structure >>    * @name: name of low level fpga manager >> @@ -191,17 +210,18 @@ 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); >> -void fpga_mgr_free(struct fpga_manager *mgr); > > removing these should cause any oot driver to fail to load. > > so an oops is unlikely. > > I'm ok with with api change. > >> -int fpga_mgr_register(struct fpga_manager *mgr); >> -void fpga_mgr_unregister(struct fpga_manager *mgr); >> +struct fpga_manager * >> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info); >>   -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr); >> +struct fpga_manager * >> +fpga_mgr_register(struct device *parent, const char *name, >> +          const struct fpga_manager_ops *mops, void *priv); > > having 2 ways to do the same thing is not great. > > this should be reduced down to 1. > > My preference is for the *info one as it's api will be durable. I would like to see if other's agree. > > Tom > >> +void fpga_mgr_unregister(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_full(struct device *parent, const struct fpga_manager_info *info); >> +struct fpga_manager * >> +devm_fpga_mgr_register(struct device *parent, const char *name, >> +               const struct fpga_manager_ops *mops, void *priv); >>     #endif /*_LINUX_FPGA_MGR_H */ >