Re: [PATCH 3/6] PCI/AER: clean all untracked pci_ops_aer when rmmod aer_inject

[Huang Ying <ying.huang@intel.com>]

On Wed, 2012-09-19 at 14:09 +0800, Yijing Wang wrote:
> On 2012/9/19 13:57, Huang Ying wrote:
> > On Wed, 2012-09-19 at 10:40 +0800, Yijing Wang wrote:
> >> Since hot plug for pci devices while doing aer inject, some newly created child buses'
> >> pci_ops will be assigned to pci_ops_aer. Aer_inject does not track these pci_ops_aer(not
> >> list in pci_bus_ops_list),we should clean all of these when rmmod aer_inject module.
> >>
> >> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> >> ---
> >>  drivers/pci/pcie/aer/aer_inject.c |   35 +++++++++++++++++++++++++++++++++++
> >>  1 files changed, 35 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c
> >> index 442147b..e2400b5 100644
> >> --- a/drivers/pci/pcie/aer/aer_inject.c
> >> +++ b/drivers/pci/pcie/aer/aer_inject.c
> >> @@ -299,6 +299,32 @@ static void pci_bus_ops_init(struct pci_bus_ops *bus_ops,
> >>  	bus_ops->ops = ops;
> >>  }
> >>  
> >> +static void pci_clean_child_aer_ops(struct pci_bus *bus)
> >> +{
> >> +	struct pci_bus *child;
> >> +
> >> +	list_for_each_entry(child, &bus->children, node) {
> >> +		if (child->ops == &pci_ops_aer)
> >> +			pci_bus_set_ops(child, bus->ops);
> >> +		pci_clean_child_aer_ops(child);
> >> +	}
> > 
> > Why not use pci_walk_bus?
> > 
> 
> I think here walk all child buses is enough, pci_walk_bus will walk all child devices under this bus.
> 
> >> +}
> >> +
> >> +/* find pci_ops_aer from root bus, and replace it by parent bus's pci_ops.
> >> + * pci_ops of root bus won't be pci_ops_aer here*/
> >> +static void clean_untracked_pci_ops_aer(void)
> >> +{
> >> +	struct pci_bus_ops *bus_ops;
> >> +
> >> +	list_for_each_entry(bus_ops, &pci_bus_ops_list, list) {
> >> +		/* the bus with untracked pci_ops_aer always the
> >> +		 * child bus of root bus tracked in pci_bus_ops_list
> >> +		 */
> >> +		if (pci_is_root_bus(bus_ops->bus))
> >> +			pci_clean_child_aer_ops(bus_ops->bus);
> >> +	}
> >> +}
> >> +
> >>  static int pci_bus_set_aer_ops(struct pci_bus *bus)
> >>  {
> >>  	struct pci_ops *ops;
> >> @@ -558,9 +584,18 @@ static void __exit aer_inject_exit(void)
> >>  
> >>  	misc_deregister(&aer_inject_device);
> >>  
> >> +	/* clean pci_bus_ops tracked in pci_bus_ops_list */
> >>  	while ((bus_ops = pci_bus_ops_get(bus_ops)))
> >>  		pci_bus_set_ops(bus_ops->bus, bus_ops->ops);
> > 
> > Why not do clean here inside loop?
> > 
> 
> Because I also need these bus_ops to scan untracked pci_ops_aer.

I mean why not call pci_clean_child_aer_ops() inside loop.

Best Regards,
Huang Ying

> > 
> >>  
> >> +	/* Inject aer errors and hotplug the same pcie device
> >> +	 * maybe assign some newly created buses' pci_ops pci_ops_aer.
> >> +	 * Since these pci_ops_aer are not tracked in pci_bus_ops_list,
> >> +	 * we need to find and clean untracked pci_ops_aer before aer_inject
> >> +	 * module exit
> >> +	 */
> >> +	clean_untracked_pci_ops_aer();
> >> +
> >>  	while ((bus_ops = pci_bus_ops_pop()))
> >>  		kfree(bus_ops);
> >>  
> > 
> > 
> > 
> > .
> > 
> 
>