Re: [PATCH 2/2] PCI: endpoint: Use link_up() callback in place of LINK_UP notifier

[Kishon Vijay Abraham I <kishon@ti.com>]

Hi Mani,

On 11/08/22 15:12, Manivannan Sadhasivam wrote:
> As a part of the transition towards callback mechanism for signalling the
> events from EPC to EPF, let's use the link_up() callback in the place of
> the LINK_UP notifier. This also removes the notifier support completely
> from the PCI endpoint framework.
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/pci/endpoint/functions/pci-epf-test.c | 33 ++++++-------------
>  drivers/pci/endpoint/pci-epc-core.c           |  8 +++--
>  include/linux/pci-epc.h                       |  8 -----
>  include/linux/pci-epf.h                       |  8 ++---
>  4 files changed, 18 insertions(+), 39 deletions(-)
> 

.
.
<snip>
.
.
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index 805f3d64f93b..a51ba9f158c3 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -690,10 +690,15 @@ EXPORT_SYMBOL_GPL(pci_epc_remove_epf);
>   */
>  void pci_epc_linkup(struct pci_epc *epc)
>  {
> +	struct pci_epf *epf;
> +
>  	if (!epc || IS_ERR(epc))
>  		return;
>  
> -	atomic_notifier_call_chain(&epc->notifier, LINK_UP, NULL);
> +	list_for_each_entry(epf, &epc->pci_epf, list) {
> +		if (epf->event_ops->link_up)
> +			epf->event_ops->link_up(epf);
> +	}

how do you ensure there is no race while invoking the call back
functions during add/remove of epf?

Thanks,
Kishon