On 8/26/2012 12:10 AM, Nicholas A. Bellinger wrote:
> On Sat, 2012-08-25 at 23:39 +0530, Naresh Kumar Inna wrote:
>> On 8/25/2012 2:47 AM, Nicholas A. Bellinger wrote:
>>> On Sat, 2012-08-25 at 00:06 +0530, Naresh Kumar Inna wrote:
>>>> On 8/24/2012 1:28 AM, Nicholas A. Bellinger wrote:
>>>>> On Fri, 2012-08-24 at 03:57 +0530, Naresh Kumar Inna wrote:
>>>>>> This patch contains the first set of the header files for csiostor driver.
>>>>>>
>>>>>> Signed-off-by: Naresh Kumar Inna <naresh@xxxxxxxxxxx>
>>>>>> ---
>>>>>> drivers/scsi/csiostor/csio_defs.h | 143 ++++++
>>>>>> drivers/scsi/csiostor/csio_fcoe_proto.h | 843 +++++++++++++++++++++++++++++++
>>>>>> drivers/scsi/csiostor/csio_hw.h | 668 ++++++++++++++++++++++++
>>>>>> drivers/scsi/csiostor/csio_init.h | 158 ++++++
>>>>>> 4 files changed, 1812 insertions(+), 0 deletions(-)
>>>>>> create mode 100644 drivers/scsi/csiostor/csio_defs.h
>>>>>> create mode 100644 drivers/scsi/csiostor/csio_fcoe_proto.h
>>>>>> create mode 100644 drivers/scsi/csiostor/csio_hw.h
>>>>>> create mode 100644 drivers/scsi/csiostor/csio_init.h
>>>>>>
>>>>>
>>>>> Hi Naresh,
>>>>>
>>>>> Just commenting on csio_defs.h bits here... As Robert mentioned, you'll
>>>>> need to convert the driver to use (or add to) upstream protocol
>>>>> definitions and drop the csio_fcoe_proto.h bits..
>>>>>
>>>>
>>>> Hi Nicholas,
>>>>
>>>> I would like take up the discussion of the protocol header file in that
>>>> email thread. Please find the rest of my replies inline.
>>>>
>>>> Thanks for reviewing,
>>>> Naresh.
>>>>
>>>>>> diff --git a/drivers/scsi/csiostor/csio_defs.h b/drivers/scsi/csiostor/csio_defs.h
>>>>>> new file mode 100644
>>>>>> index 0000000..4f1c713
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/scsi/csiostor/csio_defs.h
>
> <SNIP>
>
>>>>>> +static inline int
>>>>>> +csio_list_deleted(struct list_head *list)
>>>>>> +{
>>>>>> + return ((list->next == list) && (list->prev == list));
>>>>>> +}
>>>>>> +
>>>>>> +#define csio_list_next(elem) (((struct list_head *)(elem))->next)
>>>>>> +#define csio_list_prev(elem) (((struct list_head *)(elem))->prev)
>>>>>> +
>>>>>> +#define csio_deq_from_head(head, elem) \
>>>>>> +do { \
>>>>>> + if (!list_empty(head)) { \
>>>>>> + *((struct list_head **)(elem)) = csio_list_next((head)); \
>>>>>> + csio_list_next((head)) = \
>>>>>> + csio_list_next(csio_list_next((head))); \
>>>>>> + csio_list_prev(csio_list_next((head))) = (head); \
>>>>>> + INIT_LIST_HEAD(*((struct list_head **)(elem))); \
>>>>>> + } else \
>>>>>> + *((struct list_head **)(elem)) = (struct list_head *)NULL;\
>>>>>> +} while (0)
>>>>>> +
>>>>>
>>>>> This code is confusing as hell.. Why can't you just use normal list.h
>>>>> macros for this..?
>>>>
>>>> I have not found an equivalent function in list.h that does the above
>>>> and the following macro. Could you please point me to it? I have seen a
>>>> couple of other drivers define their own macros to achieve what this
>>>> macro does, hence I assumed there isnt a list.h macro that does this.
>>>>
>>>
>>> AFAICT all that csio_deq_from_head code is supposed to do is pull an
>>> item off a list, right..? Why not just:
>>>
>>> while (!list_empty(list)) {
>>> elem = list_first_entry(list, struct elem_type,
>>> elm_list);
>>> list_del_init(&elem->elm_list);
>>>
>>> <do work>
>>> <free *elem memory>
>>> }
>>>
>>
>> I will try to come up with a simpler static inline version of the macro.
>> Would that work?
>
> No. The point is that the above code is a disaster, and AFAICT there is
> no reason why any of it is necessary to begin with at all.
>
> Why can't csio_deq_from_head() just become list_first_entry() +
> list_del_init() to do the exact same thing without all of the extra
> overhead of list_head pointer de-reference + assignments..?
>
> --nab
>
Yes, that's what I was trying to say. csio_deq_from_head() will become
a static function comprising list_first_entry + list_del_init(), with
some checks perhaps.
Thanks,
Naresh.
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