[dpdk-dev] Clarification for eth_driver changes

[Shreyansh Jain]

On Thursday 10 November 2016 01:33 PM, Thomas Monjalon wrote:
> 2016-11-10 15:51, Jianbo Liu:
>> On 10 November 2016 at 15:26, Shreyansh Jain <shreyansh.jain at nxp.com> wrote:
>>> This is what the current outline of eth_driver is:
>>>
>>> +------------------------+
>>> | eth_driver             |
>>> | +---------------------+|
>>> | | rte_pci_driver      ||
>>> | | +------------------+||
>>> | | | rte_driver       |||
>>> | | |  name[]          |||
>>> | | |  ...             |||
>>> | | +------------------+||
>>> | |  .probe             ||
>>> | |  .remove            ||
>>> | |  ...                ||
>>> | +---------------------+|
>>> |  .eth_dev_init         |
>>> |  .eth_dev_uninit       |
>>> +------------------------+
>>>
>>> This is what I was thinking:
>>>
>>> +---------------------+        +----------------------+
>>> | rte_pci_driver      |        |eth_driver            |
>>> | +------------------+|       _|_struct rte_driver *p |
>>> | | rte_driver       <-------/ | .eth_dev_init        |
>>> | |  ...             ||        | .eth_dev_uninit      |
>>> | |  name            ||        +----------------------+
>>> | |  <more>          ||
>>> | +------------------+|
>>> |  <PCI specific info>|
>>> +---------------------+
>>>
>>> ::Impact::
>>> Various drivers use the rte_pci_driver embedded in the eth_driver object for
>>> device initialization.
>>>  == They assume that rte_pci_driver is directly embedded and hence simply
>>> dereference.
>>>  == e.g. eth_igb_dev_init() in drivers/net/e1000/igb_ethdev.c file
>>>
>>> With the above change, such drivers would have to access rte_driver and then
>>> perform container_of to obtain their respective rte_xxx_driver.
>>>  == this would be useful in case there is a non-PCI driver
>>>
>>> ::Problem::
>>> I am not sure of reason as to why eth_driver embedded rte_pci_driver in
>>> first place - other than a convenient way to define it before PCI driver
>>> registration.
>>>
>>> As all the existing PMDs are impacted - am I missing something here in
>>> making the above change?
>>>
>>
>> How do you know eth_driver->p is pointing to a rte_pci_driver or rte_soc_driver?
>> Maybe you need to add a type/flag in rte_driver.
>
> Why do you need any bus information at ethdev level?
>

AFAIK, we don't need it. Above text is not stating anything on that 
grounds either, I think. Isn't it?

-
Shreyansh