Re: [PATCH v4 16/19] fpga: dfl: allocate platform device after feature device data

["Colberg, Peter" <peter.colberg@intel.com>]

On Mon, 2024-11-18 at 23:04 +0000, Colberg, Peter wrote:
> On Mon, 2024-11-18 at 22:51 +0800, Xu Yilun wrote:
> > On Fri, Oct 25, 2024 at 06:37:11PM -0400, Peter Colberg wrote:
> > > Delay calling platform_device_alloc() from build_info_create_dev() to
> > > feature_dev_register(), now that the feature device data contains all
> > > necessary data to create the feature device. This completes the new
> > > function feature_dev_register(), which will be reused in a subsequent
> > > commit to fully recreate the feature device when assigning a port.
> > > 
> > > Signed-off-by: Peter Colberg <peter.colberg@intel.com>
> > > Reviewed-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> > > Reviewed-by: Basheer Ahmed Muddebihal <basheer.ahmed.muddebihal@linux.intel.com>
> > > ---
> > > Changes since v3:
> > > - New patch extracted from last patch of v3 series.
> > > ---
> > >  drivers/fpga/dfl.c | 59 +++++++++++++++++-----------------------------
> > >  1 file changed, 22 insertions(+), 37 deletions(-)
> > > 
> > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> > > index a9ec37278b2d..d9cef150ed0d 100644
> > > --- a/drivers/fpga/dfl.c
> > > +++ b/drivers/fpga/dfl.c
> > > @@ -681,7 +681,6 @@ EXPORT_SYMBOL_GPL(dfl_fpga_dev_ops_unregister);
> > >   * @nr_irqs: number of irqs for all feature devices.
> > >   * @irq_table: Linux IRQ numbers for all irqs, indexed by local irq index of
> > >   *	       this device.
> > > - * @feature_dev: current feature device.
> > >   * @type: the current FIU type.
> > >   * @ioaddr: header register region address of current FIU in enumeration.
> > >   * @start: register resource start of current FIU.
> > > @@ -695,7 +694,6 @@ struct build_feature_devs_info {
> > >  	unsigned int nr_irqs;
> > >  	int *irq_table;
> > >  
> > > -	struct platform_device *feature_dev;
> > >  	enum dfl_id_type type;
> > >  	void __iomem *ioaddr;
> > >  	resource_size_t start;
> > > @@ -750,7 +748,6 @@ static void dfl_id_free_action(void *arg)
> > >  static struct dfl_feature_dev_data *
> > >  binfo_create_feature_dev_data(struct build_feature_devs_info *binfo)
> > >  {
> > > -	struct platform_device *fdev = binfo->feature_dev;
> > >  	enum dfl_id_type type = binfo->type;
> > >  	struct dfl_feature_info *finfo, *p;
> > >  	struct dfl_feature_dev_data *fdata;
> > > @@ -773,7 +770,6 @@ binfo_create_feature_dev_data(struct build_feature_devs_info *binfo)
> > >  	if (!fdata->resources)
> > >  		return ERR_PTR(-ENOMEM);
> > >  
> > > -	fdata->dev = fdev;
> > >  	fdata->type = type;
> > >  
> > >  	fdata->pdev_id = dfl_id_alloc(type, binfo->dev);
> > > @@ -784,8 +780,6 @@ binfo_create_feature_dev_data(struct build_feature_devs_info *binfo)
> > >  	if (ret)
> > >  		return ERR_PTR(ret);
> > >  
> > > -	fdev->id = fdata->pdev_id;
> > > -
> > >  	fdata->pdev_name = dfl_devs[type].name;
> > >  	fdata->num = binfo->feature_num;
> > >  	fdata->dfl_cdev = binfo->cdev;
> > > @@ -809,7 +803,6 @@ binfo_create_feature_dev_data(struct build_feature_devs_info *binfo)
> > >  		unsigned int i;
> > >  
> > >  		/* save resource information for each feature */
> > > -		feature->dev = fdev;
> > >  		feature->id = finfo->fid;
> > >  		feature->revision = finfo->revision;
> > >  		feature->dfh_version = finfo->dfh_version;
> > > @@ -868,18 +861,6 @@ binfo_create_feature_dev_data(struct build_feature_devs_info *binfo)
> > >  static int
> > >  build_info_create_dev(struct build_feature_devs_info *binfo)
> > >  {
> > > -	enum dfl_id_type type = binfo->type;
> > > -	struct platform_device *fdev;
> > > -
> > > -	/*
> > > -	 * we use -ENODEV as the initialization indicator which indicates
> > > -	 * whether the id need to be reclaimed
> > > -	 */
> > > -	fdev = platform_device_alloc(dfl_devs[type].name, -ENODEV);
> > > -	if (!fdev)
> > > -		return -ENOMEM;
> > > -
> > > -	binfo->feature_dev = fdev;
> > >  	binfo->feature_num = 0;
> > >  
> > >  	INIT_LIST_HEAD(&binfo->sub_features);
> > > @@ -895,27 +876,43 @@ build_info_create_dev(struct build_feature_devs_info *binfo)
> > >  static int feature_dev_register(struct dfl_feature_dev_data *fdata)
> > >  {
> > >  	struct dfl_feature_platform_data pdata = {};
> > > -	struct platform_device *fdev = fdata->dev;
> > > +	struct platform_device *fdev;
> > > +	struct dfl_feature *feature;
> > >  	int ret;
> > >  
> > > +	fdev = platform_device_alloc(fdata->pdev_name, fdata->pdev_id);
> > > +	if (!fdev)
> > > +		return -ENOMEM;
> > > +
> > > +	fdata->dev = fdev;
> > > +
> > >  	fdev->dev.parent = &fdata->dfl_cdev->region->dev;
> > >  	fdev->dev.devt = dfl_get_devt(dfl_devs[fdata->type].devt_type, fdev->id);
> > >  
> > > +	dfl_fpga_dev_for_each_feature(fdata, feature)
> > > +		feature->dev = fdev;
> > > +
> > >  	ret = platform_device_add_resources(fdev, fdata->resources,
> > >  					    fdata->resource_num);
> > >  	if (ret)
> > > -		return ret;
> > > +		goto err_put_dev;
> > >  
> > >  	pdata.fdata = fdata;
> > >  	ret = platform_device_add_data(fdev, &pdata, sizeof(pdata));
> > >  	if (ret)
> > > -		return ret;
> > > +		goto err_put_dev;
> > >  
> > >  	ret = platform_device_add(fdev);
> > >  	if (ret)
> > > -		return ret;
> > > +		goto err_put_dev;
> > >  
> > >  	return 0;
> > > +
> > > +err_put_dev:
> > > +	platform_device_put(fdev);
> > > +	fdata->dev = NULL;
> > 
> > Do we also need to clean up all the feature->dev?
> 
> Yes, thank you for the suggestion. It is not needed for functional
> correctness since feature->dev is exclusively used when non-NULL, but
> it seems a good idea for consistency.

This has been implemented in [PATCH v5 15/18].

Thanks,
Peter

> 
> Thanks,
> Peter
> 
> > 
> > Thanks,
> > Yilun
> > 
> > > +
> > > +	return ret;
> > >  }
> > >  
> > >  static void feature_dev_unregister(struct dfl_feature_dev_data *fdata)
> > > @@ -940,16 +937,7 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
> > >  	if (binfo->type == PORT_ID)
> > >  		dfl_fpga_cdev_add_port_data(binfo->cdev, fdata);
> > >  	else
> > > -		binfo->cdev->fme_dev = get_device(&binfo->feature_dev->dev);
> > > -
> > > -	/*
> > > -	 * reset it to avoid build_info_free() freeing their resource.
> > > -	 *
> > > -	 * The resource of successfully registered feature devices
> > > -	 * will be freed by platform_device_unregister(). See the
> > > -	 * comments in build_info_create_dev().
> > > -	 */
> > > -	binfo->feature_dev = NULL;
> > > +		binfo->cdev->fme_dev = get_device(&fdata->dev->dev);
> > >  
> > >  	/* reset the binfo for next FIU */
> > >  	binfo->type = DFL_ID_MAX;
> > > @@ -966,8 +954,6 @@ static void build_info_free(struct build_feature_devs_info *binfo)
> > >  		kfree(finfo);
> > >  	}
> > >  
> > > -	platform_device_put(binfo->feature_dev);
> > > -
> > >  	devm_kfree(binfo->dev, binfo);
> > >  }
> > >  
> > > @@ -1262,8 +1248,7 @@ static int parse_feature_afu(struct build_feature_devs_info *binfo,
> > >  	case PORT_ID:
> > >  		return parse_feature_port_afu(binfo, ofst);
> > >  	default:
> > > -		dev_info(binfo->dev, "AFU belonging to FIU %s is not supported yet.\n",
> > > -			 binfo->feature_dev->name);
> > > +		dev_info(binfo->dev, "AFU belonging to FIU is not supported yet.\n");
> > >  	}
> > >  
> > >  	return 0;
> > > -- 
> > > 2.47.0
> > > 
> > > 
>