Re: [PATCH v5 09/28] fpga: dfl: add feature device infrastructure

Wu Hao
2018-06-06T12:33:26Z

On Tue, Jun 05, 2018 at 04:14:43PM -0500, Alan Tull wrote:
> On Tue, May 1, 2018 at 9:50 PM, Wu Hao <hao.wu@intel.com> wrote:
>
> Hi Hao,
>
> Some minor things, otherwise looks fine.
>
> > From: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> >
> > This patch abstracts the common operations of the sub features, and defines
> > the feature_ops data structure, including init, uinit and ioctl function
> > pointers. And this patch adds some common helper functions for FME and AFU
> > drivers, e.g dfl_feature_dev_use_begin/end which are used to ensure
> > exclusive usage of the feature device file.
> >
> > Signed-off-by: Tim Whisonant <tim.whisonant@intel.com>
> > Signed-off-by: Enno Luebbers <enno.luebbers@intel.com>
> > Signed-off-by: Shiva Rao <shiva.rao@intel.com>
> > Signed-off-by: Christopher Rauer <christopher.rauer@intel.com>
> > Signed-off-by: Kang Luwei <luwei.kang@intel.com>
> > Signed-off-by: Zhang Yi <yi.z.zhang@intel.com>
> > Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> > Signed-off-by: Wu Hao <hao.wu@intel.com>
> Acked-by: Alan Tull <atull@kernel.org>
>
> > ---
> > v2: rebased
> > v3: use const for feature_ops.
> > replace pci related function.
> > v4: rebase and add more comments in code.
> > v5: remove useless WARN_ON().
> > reorder declarations in functions per suggestion from Moritz.
> > add "dfl_" prefix to functions and data structure.
> > ---
> > drivers/fpga/dfl.c | 57 +++++++++++++++++++++++++++++++++++++
> > drivers/fpga/dfl.h | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
> > 2 files changed, 138 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> > index 1e06efb..c4c47d6 100644
> > --- a/drivers/fpga/dfl.c
> > +++ b/drivers/fpga/dfl.c
> > @@ -74,6 +74,63 @@ static enum dfl_id_type feature_dev_id_type(struct platform_device *pdev)
> > return DFL_ID_MAX;
> > }
> >
> > +void dfl_fpga_dev_feature_uinit(struct platform_device *pdev)
> > +{
> > + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
> > + struct dfl_feature *feature;
> > +
> > + dfl_fpga_dev_for_each_feature(pdata, feature)
> > + if (feature->ops) {
> > + feature->ops->uinit(pdev, feature);
> > + feature->ops = NULL;
> > + }
> > +}
> > +EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_uinit);
>
> Please add kernel-doc for functions that are exported to recommend and
> guide their usage.

Sorry, I missed uinit and init functions. will add them in v6.

>
> > +
> > +static int dfl_feature_instance_init(struct platform_device *pdev,
> > + struct dfl_feature_platform_data *pdata,
> > + struct dfl_feature *feature,
> > + struct dfl_feature_driver *drv)
> > +{
> > + int ret;
> > +
> > + ret = drv->ops->init(pdev, feature);
> > + if (ret)
> > + return ret;
> > +
> > + feature->ops = drv->ops;
> > +
> > + return ret;
> > +}
> > +
> > +int dfl_fpga_dev_feature_init(struct platform_device *pdev,
> > + struct dfl_feature_driver *feature_drvs)
> > +{
> > + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
> > + struct dfl_feature_driver *drv = feature_drvs;
> > + struct dfl_feature *feature;
> > + int ret;
> > +
> > + while (drv->ops) {
> > + dfl_fpga_dev_for_each_feature(pdata, feature) {
> > + /* match feature and drv using id */
> > + if (feature->id == drv->id) {
> > + ret = dfl_feature_instance_init(pdev, pdata,
> > + feature, drv);
> > + if (ret)
> > + goto exit;
> > + }
> > + }
> > + drv++;
> > + }
> > +
> > + return 0;
> > +exit:
> > + dfl_fpga_dev_feature_uinit(pdev);
> > + return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_init);
> > +
> > struct dfl_chardev_info {
> > const char *name;
> > dev_t devt;
> > diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
> > index 2b6aaef..27f7a74 100644
> > --- a/drivers/fpga/dfl.h
> > +++ b/drivers/fpga/dfl.h
> > @@ -132,6 +132,17 @@
> > #define PORT_CTRL_SFTRST_ACK BIT_ULL(4) /* HW ack for reset */
> >
> > /**
> > + * struct dfl_feature_driver - sub feature's driver
> > + *
> > + * @id: sub feature id.
> > + * @ops: ops of this sub feature.
> > + */
> > +struct dfl_feature_driver {
> > + u64 id;
> > + const struct dfl_feature_ops *ops;
> > +};
> > +
> > +/**
> > * struct dfl_feature - sub feature of the feature devices
> > *
> > * @id: sub feature id.
> > @@ -139,13 +150,17 @@
> > * this index is used to find its mmio resource from the
> > * feature dev (platform device)'s reources.
> > * @ioaddr: mapped mmio resource address.
> > + * @ops: ops of this sub feature.
> > */
> > struct dfl_feature {
> > u64 id;
> > int resource_index;
> > void __iomem *ioaddr;
> > + const struct dfl_feature_ops *ops;
> > };
> >
> > +#define DEV_STATUS_IN_USE 0
> > +
> > /**
> > * struct dfl_feature_platform_data - platform data for feature devices
> > *
> > @@ -156,6 +171,8 @@ struct dfl_feature {
> > * @dfl_cdev: ptr to container device.
> > * @disable_count: count for port disable.
> > * @num: number for sub features.
> > + * @dev_status: dev status (e.g DEV_STATUS_IN_USE).
> > + * @private: ptr to feature dev private data.
> > * @features: sub features of this feature dev.
> > */
> > struct dfl_feature_platform_data {
> > @@ -165,11 +182,49 @@ struct dfl_feature_platform_data {
> > struct platform_device *dev;
> > struct dfl_fpga_cdev *dfl_cdev;
> > unsigned int disable_count;
> > -
> > + unsigned long dev_status;
> > + void *private;
> > int num;
> > struct dfl_feature features[0];
> > };
> >
> > +static inline
> > +int dfl_feature_dev_use_begin(struct dfl_feature_platform_data *pdata)
> > +{
> > + /* Test and set IN_USE flags to ensure file is exclusively used */
> > + if (test_and_set_bit_lock(DEV_STATUS_IN_USE, &pdata->dev_status))
> > + return -EBUSY;
> > +
> > + return 0;
> > +}
> > +
> > +static inline
> > +void dfl_feature_dev_use_end(struct dfl_feature_platform_data *pdata)
> > +{
> > + clear_bit_unlock(DEV_STATUS_IN_USE, &pdata->dev_status);
> > +}
> > +
> > +static inline
> > +void dfl_fpga_pdata_set_private(struct dfl_feature_platform_data *pdata,
> > + void *private)
> > +{
> > + pdata->private = private;
> > +}
> > +
> > +static inline
> > +void *dfl_fpga_pdata_get_private(struct dfl_feature_platform_data *pdata)
> > +{
> > + return pdata->private;
> > +}
> > +
> > +struct dfl_feature_ops {
> > + int (*init)(struct platform_device *pdev, struct dfl_feature *feature);
> > + void (*uinit)(struct platform_device *pdev,
> > + struct dfl_feature *feature);
> > + long (*ioctl)(struct platform_device *pdev, struct dfl_feature *feature,
> > + unsigned int cmd, unsigned long arg);
> > +};
> > +
> > #define DFL_FPGA_FEATURE_DEV_FME "dfl-fme"
> > #define DFL_FPGA_FEATURE_DEV_PORT "dfl-port"
>
> Please move these to the same place as other things that will need to
> be added to as feature devices are added as noted in the other reviews
> today.

as these two strings are used as platform device name, so I think we need to
keep them in the dfl.h file, because platform driver could reuse the same.
But I will add detailed comments to guide others to put name string for new
feature device (platform device) in the dfl.h file together with above ones.

Thanks a lot for the review.
Hao