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.
fpga_mgr_register() calls device_add(), so fpga_mgr_unregister() should
call device_del().
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 */
