RE: [PATCH] PCI: hv: Fix build error without CONFIG_SYSFS

RE: [PATCH] PCI: hv: Fix build error without CONFIG_SYSFS

[Michael Kelley]

From: YueHaibing <yuehaibing@huawei.com>  Sent: Friday, May 31, 2019 8:09 AM
> 
> while building without CONFIG_SYSFS, fails as below:
> 
> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_assign_slots':
> pci-hyperv.c:(.text+0x40a): undefined reference to 'pci_create_slot'
> drivers/pci/controller/pci-hyperv.o: In function 'pci_devices_present_work':
> pci-hyperv.c:(.text+0xc02): undefined reference to 'pci_destroy_slot'
> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_remove':
> pci-hyperv.c:(.text+0xe50): undefined reference to 'pci_destroy_slot'
> drivers/pci/controller/pci-hyperv.o: In function 'hv_eject_device_work':
> pci-hyperv.c:(.text+0x11f9): undefined reference to 'pci_destroy_slot'
> 
> Select SYSFS while PCI_HYPERV is set to fix this.
> 

I'm wondering if is the right way to fix the problem.  Conceptually
is it possible to setup & operate virtual PCI devices like 
pci-hyperv.c does, even if sysfs is not present?  Or is it right to
always required sysfs?

The function pci_dev_assign_slot() in slot.c has a null implementation
in include/linux/pci.h when CONFIG_SYSFS is not defined, which
seems to be trying to solve the same problem for that function.  And
if CONFIG_HOTPLUG_PCI is defined but CONFIG_SYSFS is not,
pci_hp_create_module_link() and pci_hp_remove_module_link()
look like they would have the same problem.  Maybe there should
be degenerate implementations of pci_create_slot() and
pci_destroy_slot() for cases when CONFIG_SYSFS is not defined?

But I'll admit I don't know the full story behind how PCI slots
are represented and used, so maybe I'm off base.  I just noticed
the inconsistency in how other functions in slot.c are handled.

Thoughts?

Michael

Re: [PATCH] PCI: hv: Fix build error without CONFIG_SYSFS

[Yuehaibing]

On 2019/6/2 6:59, Michael Kelley wrote:
> From: YueHaibing <yuehaibing@huawei.com>  Sent: Friday, May 31, 2019 8:09 AM
>>
>> while building without CONFIG_SYSFS, fails as below:
>>
>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_assign_slots':
>> pci-hyperv.c:(.text+0x40a): undefined reference to 'pci_create_slot'
>> drivers/pci/controller/pci-hyperv.o: In function 'pci_devices_present_work':
>> pci-hyperv.c:(.text+0xc02): undefined reference to 'pci_destroy_slot'
>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_remove':
>> pci-hyperv.c:(.text+0xe50): undefined reference to 'pci_destroy_slot'
>> drivers/pci/controller/pci-hyperv.o: In function 'hv_eject_device_work':
>> pci-hyperv.c:(.text+0x11f9): undefined reference to 'pci_destroy_slot'
>>
>> Select SYSFS while PCI_HYPERV is set to fix this.
>>
> 
> I'm wondering if is the right way to fix the problem.  Conceptually
> is it possible to setup & operate virtual PCI devices like 
> pci-hyperv.c does, even if sysfs is not present?  Or is it right to
> always required sysfs?
> 
> The function pci_dev_assign_slot() in slot.c has a null implementation
> in include/linux/pci.h when CONFIG_SYSFS is not defined, which
> seems to be trying to solve the same problem for that function.  And
> if CONFIG_HOTPLUG_PCI is defined but CONFIG_SYSFS is not,
> pci_hp_create_module_link() and pci_hp_remove_module_link()
> look like they would have the same problem.  Maybe there should
> be degenerate implementations of pci_create_slot() and
> pci_destroy_slot() for cases when CONFIG_SYSFS is not defined?
> 
> But I'll admit I don't know the full story behind how PCI slots
> are represented and used, so maybe I'm off base.  I just noticed
> the inconsistency in how other functions in slot.c are handled.
> 
> Thoughts?

268a03a42d33 ("PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS")

make slot.o depends CONFIG_SYSFS

commit 268a03a42d3377d5fb41e6e7cbdec4e0b65cab2e
Author: Alex Chiang <achiang@hp.com>
Date:   Wed Jun 17 19:03:57 2009 -0600

    PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS

    There is no way to interact with a physical PCI slot without
    sysfs, so encode the dependency and prevent this build error:

        drivers/pci/slot.c: In function 'pci_hp_create_module_link':
        drivers/pci/slot.c:327: error: 'module_kset' undeclared

    This patch _should_ make pci-sysfs.o depend on CONFIG_SYSFS too,
    but we cannot (yet) because the PCI core merrily assumes the
    existence of sysfs:

        drivers/built-in.o: In function `pci_bus_add_device':
        drivers/pci/bus.c:89: undefined reference to `pci_create_sysfs_dev_files'
        drivers/built-in.o: In function `pci_stop_dev':
        drivers/pci/remove.c:24: undefined reference to `pci_remove_sysfs_dev_files'

    So do the minimal bit for now and figure out how to untangle it
    later.

If No CONFIG_SYSFS, slot.o is not build

> 
> Michael
> 
> 

Re: [PATCH] PCI: hv: Fix build error without CONFIG_SYSFS

[Yuehaibing]

+cc Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

On 2019/6/15 14:18, Yuehaibing wrote:
> 
> On 2019/6/2 6:59, Michael Kelley wrote:
>> From: YueHaibing <yuehaibing@huawei.com>  Sent: Friday, May 31, 2019 8:09 AM
>>>
>>> while building without CONFIG_SYSFS, fails as below:
>>>
>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_assign_slots':
>>> pci-hyperv.c:(.text+0x40a): undefined reference to 'pci_create_slot'
>>> drivers/pci/controller/pci-hyperv.o: In function 'pci_devices_present_work':
>>> pci-hyperv.c:(.text+0xc02): undefined reference to 'pci_destroy_slot'
>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_remove':
>>> pci-hyperv.c:(.text+0xe50): undefined reference to 'pci_destroy_slot'
>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_eject_device_work':
>>> pci-hyperv.c:(.text+0x11f9): undefined reference to 'pci_destroy_slot'
>>>
>>> Select SYSFS while PCI_HYPERV is set to fix this.
>>>
>>
>> I'm wondering if is the right way to fix the problem.  Conceptually
>> is it possible to setup & operate virtual PCI devices like 
>> pci-hyperv.c does, even if sysfs is not present?  Or is it right to
>> always required sysfs?
>>
>> The function pci_dev_assign_slot() in slot.c has a null implementation
>> in include/linux/pci.h when CONFIG_SYSFS is not defined, which
>> seems to be trying to solve the same problem for that function.  And
>> if CONFIG_HOTPLUG_PCI is defined but CONFIG_SYSFS is not,
>> pci_hp_create_module_link() and pci_hp_remove_module_link()
>> look like they would have the same problem.  Maybe there should
>> be degenerate implementations of pci_create_slot() and
>> pci_destroy_slot() for cases when CONFIG_SYSFS is not defined?
>>
>> But I'll admit I don't know the full story behind how PCI slots
>> are represented and used, so maybe I'm off base.  I just noticed
>> the inconsistency in how other functions in slot.c are handled.
>>
>> Thoughts?
> 
> 268a03a42d33 ("PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS")
> 
> make slot.o depends CONFIG_SYSFS
> 
> commit 268a03a42d3377d5fb41e6e7cbdec4e0b65cab2e
> Author: Alex Chiang <achiang@hp.com>
> Date:   Wed Jun 17 19:03:57 2009 -0600
> 
>     PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS
> 
>     There is no way to interact with a physical PCI slot without
>     sysfs, so encode the dependency and prevent this build error:
> 
>         drivers/pci/slot.c: In function 'pci_hp_create_module_link':
>         drivers/pci/slot.c:327: error: 'module_kset' undeclared
> 
>     This patch _should_ make pci-sysfs.o depend on CONFIG_SYSFS too,
>     but we cannot (yet) because the PCI core merrily assumes the
>     existence of sysfs:
> 
>         drivers/built-in.o: In function `pci_bus_add_device':
>         drivers/pci/bus.c:89: undefined reference to `pci_create_sysfs_dev_files'
>         drivers/built-in.o: In function `pci_stop_dev':
>         drivers/pci/remove.c:24: undefined reference to `pci_remove_sysfs_dev_files'
> 
>     So do the minimal bit for now and figure out how to untangle it
>     later.
> 
> If No CONFIG_SYSFS, slot.o is not build
> 
>>
>> Michael
>>
>>
> 
> 
> .
> 

Re: [PATCH] PCI: hv: Fix build error without CONFIG_SYSFS

[Lorenzo Pieralisi]

On Sat, Jun 15, 2019 at 02:48:24PM +0800, Yuehaibing wrote:
> +cc Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Can we drop this patch and merge:

https://patchwork.ozlabs.org/patch/1131444/

instead ?

Thanks,
Lorenzo

> 
> On 2019/6/15 14:18, Yuehaibing wrote:
> > 
> > On 2019/6/2 6:59, Michael Kelley wrote:
> >> From: YueHaibing <yuehaibing@huawei.com>  Sent: Friday, May 31, 2019 8:09 AM
> >>>
> >>> while building without CONFIG_SYSFS, fails as below:
> >>>
> >>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_assign_slots':
> >>> pci-hyperv.c:(.text+0x40a): undefined reference to 'pci_create_slot'
> >>> drivers/pci/controller/pci-hyperv.o: In function 'pci_devices_present_work':
> >>> pci-hyperv.c:(.text+0xc02): undefined reference to 'pci_destroy_slot'
> >>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_remove':
> >>> pci-hyperv.c:(.text+0xe50): undefined reference to 'pci_destroy_slot'
> >>> drivers/pci/controller/pci-hyperv.o: In function 'hv_eject_device_work':
> >>> pci-hyperv.c:(.text+0x11f9): undefined reference to 'pci_destroy_slot'
> >>>
> >>> Select SYSFS while PCI_HYPERV is set to fix this.
> >>>
> >>
> >> I'm wondering if is the right way to fix the problem.  Conceptually
> >> is it possible to setup & operate virtual PCI devices like 
> >> pci-hyperv.c does, even if sysfs is not present?  Or is it right to
> >> always required sysfs?
> >>
> >> The function pci_dev_assign_slot() in slot.c has a null implementation
> >> in include/linux/pci.h when CONFIG_SYSFS is not defined, which
> >> seems to be trying to solve the same problem for that function.  And
> >> if CONFIG_HOTPLUG_PCI is defined but CONFIG_SYSFS is not,
> >> pci_hp_create_module_link() and pci_hp_remove_module_link()
> >> look like they would have the same problem.  Maybe there should
> >> be degenerate implementations of pci_create_slot() and
> >> pci_destroy_slot() for cases when CONFIG_SYSFS is not defined?
> >>
> >> But I'll admit I don't know the full story behind how PCI slots
> >> are represented and used, so maybe I'm off base.  I just noticed
> >> the inconsistency in how other functions in slot.c are handled.
> >>
> >> Thoughts?
> > 
> > 268a03a42d33 ("PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS")
> > 
> > make slot.o depends CONFIG_SYSFS
> > 
> > commit 268a03a42d3377d5fb41e6e7cbdec4e0b65cab2e
> > Author: Alex Chiang <achiang@hp.com>
> > Date:   Wed Jun 17 19:03:57 2009 -0600
> > 
> >     PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS
> > 
> >     There is no way to interact with a physical PCI slot without
> >     sysfs, so encode the dependency and prevent this build error:
> > 
> >         drivers/pci/slot.c: In function 'pci_hp_create_module_link':
> >         drivers/pci/slot.c:327: error: 'module_kset' undeclared
> > 
> >     This patch _should_ make pci-sysfs.o depend on CONFIG_SYSFS too,
> >     but we cannot (yet) because the PCI core merrily assumes the
> >     existence of sysfs:
> > 
> >         drivers/built-in.o: In function `pci_bus_add_device':
> >         drivers/pci/bus.c:89: undefined reference to `pci_create_sysfs_dev_files'
> >         drivers/built-in.o: In function `pci_stop_dev':
> >         drivers/pci/remove.c:24: undefined reference to `pci_remove_sysfs_dev_files'
> > 
> >     So do the minimal bit for now and figure out how to untangle it
> >     later.
> > 
> > If No CONFIG_SYSFS, slot.o is not build
> > 
> >>
> >> Michael
> >>
> >>
> > 
> > 
> > .
> > 
> 

Re: [PATCH] PCI: hv: Fix build error without CONFIG_SYSFS

[Yuehaibing]

On 2019/8/13 18:18, Lorenzo Pieralisi wrote:
> On Sat, Jun 15, 2019 at 02:48:24PM +0800, Yuehaibing wrote:
>> +cc Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> 
> Can we drop this patch and merge:
> 
> https://patchwork.ozlabs.org/patch/1131444/
> 
> instead ?

Ok, it looks good to me, thanks!

> 
> Thanks,
> Lorenzo
> 
>>
>> On 2019/6/15 14:18, Yuehaibing wrote:
>>>
>>> On 2019/6/2 6:59, Michael Kelley wrote:
>>>> From: YueHaibing <yuehaibing@huawei.com>  Sent: Friday, May 31, 2019 8:09 AM
>>>>>
>>>>> while building without CONFIG_SYSFS, fails as below:
>>>>>
>>>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_assign_slots':
>>>>> pci-hyperv.c:(.text+0x40a): undefined reference to 'pci_create_slot'
>>>>> drivers/pci/controller/pci-hyperv.o: In function 'pci_devices_present_work':
>>>>> pci-hyperv.c:(.text+0xc02): undefined reference to 'pci_destroy_slot'
>>>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_pci_remove':
>>>>> pci-hyperv.c:(.text+0xe50): undefined reference to 'pci_destroy_slot'
>>>>> drivers/pci/controller/pci-hyperv.o: In function 'hv_eject_device_work':
>>>>> pci-hyperv.c:(.text+0x11f9): undefined reference to 'pci_destroy_slot'
>>>>>
>>>>> Select SYSFS while PCI_HYPERV is set to fix this.
>>>>>
>>>>
>>>> I'm wondering if is the right way to fix the problem.  Conceptually
>>>> is it possible to setup & operate virtual PCI devices like 
>>>> pci-hyperv.c does, even if sysfs is not present?  Or is it right to
>>>> always required sysfs?
>>>>
>>>> The function pci_dev_assign_slot() in slot.c has a null implementation
>>>> in include/linux/pci.h when CONFIG_SYSFS is not defined, which
>>>> seems to be trying to solve the same problem for that function.  And
>>>> if CONFIG_HOTPLUG_PCI is defined but CONFIG_SYSFS is not,
>>>> pci_hp_create_module_link() and pci_hp_remove_module_link()
>>>> look like they would have the same problem.  Maybe there should
>>>> be degenerate implementations of pci_create_slot() and
>>>> pci_destroy_slot() for cases when CONFIG_SYSFS is not defined?
>>>>
>>>> But I'll admit I don't know the full story behind how PCI slots
>>>> are represented and used, so maybe I'm off base.  I just noticed
>>>> the inconsistency in how other functions in slot.c are handled.
>>>>
>>>> Thoughts?
>>>
>>> 268a03a42d33 ("PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS")
>>>
>>> make slot.o depends CONFIG_SYSFS
>>>
>>> commit 268a03a42d3377d5fb41e6e7cbdec4e0b65cab2e
>>> Author: Alex Chiang <achiang@hp.com>
>>> Date:   Wed Jun 17 19:03:57 2009 -0600
>>>
>>>     PCI: drivers/pci/slot.c should depend on CONFIG_SYSFS
>>>
>>>     There is no way to interact with a physical PCI slot without
>>>     sysfs, so encode the dependency and prevent this build error:
>>>
>>>         drivers/pci/slot.c: In function 'pci_hp_create_module_link':
>>>         drivers/pci/slot.c:327: error: 'module_kset' undeclared
>>>
>>>     This patch _should_ make pci-sysfs.o depend on CONFIG_SYSFS too,
>>>     but we cannot (yet) because the PCI core merrily assumes the
>>>     existence of sysfs:
>>>
>>>         drivers/built-in.o: In function `pci_bus_add_device':
>>>         drivers/pci/bus.c:89: undefined reference to `pci_create_sysfs_dev_files'
>>>         drivers/built-in.o: In function `pci_stop_dev':
>>>         drivers/pci/remove.c:24: undefined reference to `pci_remove_sysfs_dev_files'
>>>
>>>     So do the minimal bit for now and figure out how to untangle it
>>>     later.
>>>
>>> If No CONFIG_SYSFS, slot.o is not build
>>>
>>>>
>>>> Michael
>>>>
>>>>
>>>
>>>
>>> .
>>>
>>
> 
> .
>