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 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?

> +}
> +
> +/* 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?

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);
>