Re: [RFC] pci: Rework config space blocking services

From: Jan Kiszka
Date: Tue Sep 06 2011 - 04:48:36 EST


On 2011-09-06 10:47, Michael S. Tsirkin wrote:
> On Tue, Sep 06, 2011 at 10:27:45AM +0200, Jan Kiszka wrote:
>> On 2011-09-06 10:04, Michael S. Tsirkin wrote:
>>> On Tue, Sep 06, 2011 at 09:18:13AM +0200, Jan Kiszka wrote:
>>>>>> @@ -401,36 +403,58 @@ int pci_vpd_truncate(struct pci_dev *dev, size_t size)
>>>>>> EXPORT_SYMBOL(pci_vpd_truncate);
>>>>>>
>>>>>> /**
>>>>>> - * pci_block_user_cfg_access - Block userspace PCI config reads/writes
>>>>>> + * pci_block_cfg_access - Block PCI config reads/writes
>>>>>
>>>>> This comment seems confusing. We don't in fact block all config
>>>>> reads writes. Instead we block userspace accesses and
>>>>> concurrent block requests.
>>>>
>>>> I'm open for a better suggestion that summarize the more verbose (and
>>>> hopefully clearer) explanation below.
>>>
>>> I think the problem is, it doesn't block config access
>>> and we call it pci_block_cfg_access.
>>>
>>> Thinking about it, doesn't this behave somewhat like a lock?
>>> How about
>>>
>>> pci_user_cfg_access_trylock
>>> pci_user_cfg_access_lock
>>> pci_user_cfg_access_unlock
>>>
>>> And then:
>>> * pci_user_cfg_access_lock - Lock userspace PCI config access
>>
>> Except that the "userspace" here is still only half of the truth
>
> It's the name of the lock :)

Ah, blind. That has to be change as well of course (pci_cfg_access_*lock).

Jan

--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
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