On 6/7/21 6:40 PM, Xu Yilun wrote:
> On Mon, Jun 07, 2021 at 04:50:58PM -0700, Russ Weight wrote:
>>
>> 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 <russell.h.weight@xxxxxxxxx>
>>>>>>> ---
>>>>>>> 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 real problem is the non-devm functions.
>
> fpga_mgr_create() calls device_initialize() so fpga_mgr_free() should call
> put_device() for deinitialization.
Yes - I understand that. The error case also needs to be fixed to call put_device()
on error.
>
> fpga_mgr_register() calls device_add(), so fpga_mgr_unregister() should
> call device_del().
OK - so your answer to my question is that fpga_mgr_unregister() should call
device_del() instead of device_unregister(). I can see how that will work.
I'll try to submit a new patchset today.
Thanks,
- Russ
>
> Thanks,
> Yilun
>
>> 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 */
