Re: [RESEND PATCH v10 0/3] fpga: Use standard class dev_release function

[Russ Weight <russell.h.weight@intel.com>]

On 7/27/21 10:44 AM, Tom Rix wrote:
>
> On 7/27/21 10:16 AM, Russ Weight wrote:
>>
>> On 7/27/21 9:55 AM, Tom Rix wrote:
>>> On 7/27/21 9:38 AM, Russ Weight wrote:
>>>> On 7/27/21 9:22 AM, Tom Rix wrote:
>>>>> On 7/27/21 9:15 AM, Russ Weight wrote:
>>>>>> On 7/27/21 6:24 AM, Tom Rix wrote:
>>>>>>> On 7/26/21 2:33 PM, Russ Weight wrote:
>>>>>>>> Hi Moritz,
>>>>>>>>
>>>>>>>> I sent this version of the patchset out on July 8th. The only discussion has
>>>>>>>> been around the compat-id structure. I think there is agreement that this can
>>>>>>>> be treated separately. What are your thoughts? Do you think this patchset is
>>>>>>>> ready?
>>>>>>> While I agree the compat_id can be treated separately, i still have a problem with the 2 register functions.
>>>>>>>
>>>>>>> In this discussion,
>>>>>>>
>>>>>>> https://lore.kernel.org/linux-fpga/DM6PR11MB38194D113950FA4B75C7F2C485E49@DM6PR11MB3819.namprd11.prod.outlook.com/
>>>>>>>
>>>>>>> *register_full(..., *info) becomes
>>>>>>>
>>>>>>> *register(..., *info)
>>>>>>>
>>>>>>> and
>>>>>>>
>>>>>>> *register_simple() is moved out of the public api and becomes private to the subsystem.
>>>>>> Somehow I missed that part of the email. I'm not sure I understand the part about
>>>>>> register_simple() "becomes private to the subsystem". Most users would call the simple
>>>>>> version of the API. Is the proposal to replicate the register_simple() interface
>>>>>> for each driver that calls it?
>>>>> Still use *register_simple() internally, so most of your patchset is unchanged.
>>>>>
>>>>> Move it out the public api. include/linux/fpga-mgr.h into someplace appropriate in drivers/fpga/
>>>> Ok - I'll do another spin of the patch set.
>>>>
>>>> Just to be clear, *register_full() gets renamed back to *register(). The current *register()
>>>> goes back to *register_simple(). *register_simple() is an exported symbol, but the function
>>>> prototype moves out of the public header file into private header file under drivers/fpga.
>>> Mostly.
>>>
>>> If register_simple does not need to be exported, it shouldn't be.
>> If *register_simple() is to reside in the fpga_mgr or fpga_region module and be
>> called by other modules, then it has to be exported... unless it is defined as a
>> static function in a header file. Shall I go that route instead? I could create
>> a new drivers/fpga/fpga.h file and add the *register_simple() functions there.
>> Or I could create separate drivers/fpga/fpga-mgr.h and drivers/fpga/fpga-region.h
>> header files with one static function each.
>
> good point, exporting ok

Before I do this, can I get others to chime in? There was a previous patchset that
used *register_simple() and *register(). It seemed that the consensus at that time
was that it should be *register() and *register_full(). I'm starting to feel like
I'm going in circles...

I personally don't have a problem with two public flavors of the register function
(the way it is now), what do other's think? If it really is a problem to have two
versions of the register function, maybe I should just change all of the callers
to declare a structure and call the same register function?

- Russ


>
> Tom
>
>>
>> - Russ
>>
>>> Tom
>>>
>>>> - Russ
>>>>
>>>>> Tom
>>>>>
>>>>>>> Tom
>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> - Russ
>>>>>>>>
>>>>>>>>
>>>>>>>> On 7/26/21 2:27 PM, Russ Weight wrote:
>>>>>>>>> The FPGA framework has a convention of using managed resource functions
>>>>>>>>> to allow parent drivers to manage the data structures allocated by the
>>>>>>>>> class drivers. They use an empty *_dev_release() function to satisfy the
>>>>>>>>> class driver.
>>>>>>>>>
>>>>>>>>> This is inconsistent with linux driver model.
>>>>>>>>>
>>>>>>>>> These changes remove the managed resource functions and populate the class
>>>>>>>>> dev_release callback functions. They also merge the create() and register()
>>>>>>>>> functions into a single register() or register_full() function for each of
>>>>>>>>> the fpga-mgr, fpga-region, and fpga-bridge class drivers.
>>>>>>>>>
>>>>>>>>> The new *register_full() functions accept an info data structure to provide
>>>>>>>>> flexibility in passing optional parameters. The *register() functions
>>>>>>>>> support the legacy parameter list for users that don't require the use of
>>>>>>>>> optional parameters.
>>>>>>>>>
>>>>>>>>> For more context, refer to this email thread:
>>>>>>>>>
>>>>>>>>> https://marc.info/?l=linux-fpga&m=162127412218557&w=2
>>>>>>>>>
>>>>>>>>> I turned on the configs assocated with each of the modified files, but I
>>>>>>>>> must have been missing some dependencies, because not all of them compiled.
>>>>>>>>> I did a run-time test specifically with the dfl-fme infrastructure. This
>>>>>>>>> would have exercised the region, bridge, and fpga-mgr frameworks.
>>>>>>>>>
>>>>>>>>> Changelog v9 -> v10:
>>>>>>>>>       - Fixed commit messages to reference register_full() instead of
>>>>>>>>>         register_simple().
>>>>>>>>>       - Removed the fpga_bridge_register_full() function, because there is
>>>>>>>>>         not need for it yet. Updated the documentation and commit message
>>>>>>>>>         accordingly.
>>>>>>>>>       - Updated documentation to reference the fpga_manager_info and
>>>>>>>>>         fpga_region_info structures.
>>>>>>>>>
>>>>>>>>> Changelog v8 -> v9:
>>>>>>>>>       - Cleaned up documentation for the FPGA Manager, Bridge, and Region
>>>>>>>>>         register functions
>>>>>>>>>       - Renamed fpga_*_register() to fpga_*_register_full()
>>>>>>>>>       - Renamed fpga_*_register_simple() to fpga_*_register()
>>>>>>>>>       - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>>>>>>>>       - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>>>>>>>>>
>>>>>>>>> Changelog v7 -> v8:
>>>>>>>>>       - Added reviewed-by tags.
>>>>>>>>>       - Updated Documentation/driver-api/fpga/ files: fpga-mgr.rst,
>>>>>>>>>         fpga-bridge.rst, and fpga-region.rst.
>>>>>>>>>
>>>>>>>>> Changelog v6 -> v7:
>>>>>>>>>       - Update the commit messages to describe the new parameters for the
>>>>>>>>>         *register() functions and to mention the *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 definitions/prototypes to apply const to the new info
>>>>>>>>>         parameter.
>>>>>>>>>       - Verify that info->br_ops is non-null in the fpga_bridge_register()
>>>>>>>>>         function.
>>>>>>>>>       - Verify a non-null info pointer in the fpga_region_register() function.
>>>>>>>>>
>>>>>>>>> Changelog v5 -> v6:
>>>>>>>>>       - Moved FPGA manager/bridge/region optional parameters out of the ops
>>>>>>>>>         structure and back into the FPGA class driver structure.
>>>>>>>>>       - Changed fpga_*_register() function parameters to accept an info data
>>>>>>>>>         structure to provide flexibility in passing optional parameters.
>>>>>>>>>       - Added fpga_*_register_simple() functions to support current parameters
>>>>>>>>>         for users that don't require use of optional parameters.
>>>>>>>>>
>>>>>>>>> Changelog v4 -> 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.
>>>>>>>>>       - Created the fpga_region_ops data structure which is optionally passed
>>>>>>>>>         to fpga_region_register(). compat_id, the get_bridges() pointer, and
>>>>>>>>>         the priv pointer are included in the fpga_region_ops structure.
>>>>>>>>>
>>>>>>>>> Changelog v3 -> 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.
>>>>>>>>>       - Added the compat_id parameter to fpga_region_register() to ensure
>>>>>>>>>         that the compat_id is set before the device_register() call.
>>>>>>>>>       - Modified the dfl_fpga_feature_devs_enumerate() function to restore
>>>>>>>>>         the fpga_region_register() call to the correct location.
>>>>>>>>>
>>>>>>>>> Changelog v2 -> v3:
>>>>>>>>>       - Cleaned up comment headers for fpga_mgr_register(), fpga_bridge_register(),
>>>>>>>>>         and fpga_region_register().
>>>>>>>>>       - Fixed error return on ida_simple_get() failure for fpga_mgr_register(),
>>>>>>>>>         fpga_bridge_register(), and fpga_region_register().
>>>>>>>>>       - Fixed error return value for fpga_bridge_register(): ERR_PTR(ret) instead
>>>>>>>>>         of NULL.
>>>>>>>>>
>>>>>>>>> Changelog v1 -> v2:
>>>>>>>>>       - Restored devm_fpga_mgr_register() functionality to the fpga-mgr
>>>>>>>>>         class driver, 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.
>>>>>>>>>
>>>>>>>>> Russ Weight (3):
>>>>>>>>>       fpga: mgr: Use standard dev_release for class driver
>>>>>>>>>       fpga: bridge: Use standard dev_release for class driver
>>>>>>>>>       fpga: region: Use standard dev_release for class driver
>>>>>>>>>
>>>>>>>>>      Documentation/driver-api/fpga/fpga-bridge.rst |   6 +-
>>>>>>>>>      Documentation/driver-api/fpga/fpga-mgr.rst    |  38 +++-
>>>>>>>>>      Documentation/driver-api/fpga/fpga-region.rst |  12 +-
>>>>>>>>>      drivers/fpga/altera-cvp.c                     |  12 +-
>>>>>>>>>      drivers/fpga/altera-fpga2sdram.c              |  12 +-
>>>>>>>>>      drivers/fpga/altera-freeze-bridge.c           |  10 +-
>>>>>>>>>      drivers/fpga/altera-hps2fpga.c                |  12 +-
>>>>>>>>>      drivers/fpga/altera-pr-ip-core.c              |   7 +-
>>>>>>>>>      drivers/fpga/altera-ps-spi.c                  |   9 +-
>>>>>>>>>      drivers/fpga/dfl-fme-br.c                     |  10 +-
>>>>>>>>>      drivers/fpga/dfl-fme-mgr.c                    |  22 +-
>>>>>>>>>      drivers/fpga/dfl-fme-region.c                 |  17 +-
>>>>>>>>>      drivers/fpga/dfl.c                            |  12 +-
>>>>>>>>>      drivers/fpga/fpga-bridge.c                    | 122 +++-------
>>>>>>>>>      drivers/fpga/fpga-mgr.c                       | 215 ++++++++----------
>>>>>>>>>      drivers/fpga/fpga-region.c                    | 119 ++++------
>>>>>>>>>      drivers/fpga/ice40-spi.c                      |   9 +-
>>>>>>>>>      drivers/fpga/machxo2-spi.c                    |   9 +-
>>>>>>>>>      drivers/fpga/of-fpga-region.c                 |  10 +-
>>>>>>>>>      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-pr-decoupler.c            |  17 +-
>>>>>>>>>      drivers/fpga/xilinx-spi.c                     |  11 +-
>>>>>>>>>      drivers/fpga/zynq-fpga.c                      |  16 +-
>>>>>>>>>      drivers/fpga/zynqmp-fpga.c                    |   9 +-
>>>>>>>>>      include/linux/fpga/fpga-bridge.h              |  30 ++-
>>>>>>>>>      include/linux/fpga/fpga-mgr.h                 |  62 +++--
>>>>>>>>>      include/linux/fpga/fpga-region.h              |  36 ++-
>>>>>>>>>      30 files changed, 383 insertions(+), 511 deletions(-)
>>>>>>>>>
>