Re: [PATCH -next v2] PCI: endpoint: pci-epf-vntb: fix error handle in epf_ntb_mw_bar_init()

[Bjorn Helgaas <helgaas@kernel.org>]

On Sat, Jun 25, 2022 at 10:15:16AM +0800, Yang Yingliang wrote:
> In error case of epf_ntb_mw_bar_init(), memory window BARs should be
> cleared, so add 'num_mws' parameter in epf_ntb_mw_bar_clear() and
> calling it in error path to clear the BARs. Also add missing error
> code when pci_epc_mem_alloc_addr() fails.

Another one for Jon, since ff32fac00d97 appeared in -next via his
tree

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=ff32fac00d97

> Fixes: ff32fac00d97 ("NTB: EPF: support NTB transfer between PCI RC and EP connection")
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
> v2:
>   add error label err_set_bar and move pci_epc_clear_bar() to it
> ---
>  drivers/pci/endpoint/functions/pci-epf-vntb.c | 20 ++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index ebf7e243eefa..ee9fee167d48 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -567,6 +567,8 @@ static int epf_ntb_db_bar_init(struct epf_ntb *ntb)
>  	return -1;
>  }
>  
> +static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws);
> +
>  /**
>   * epf_ntb_db_bar_clear() - Clear doorbell BAR and free memory
>   *   allocated in peers outbound address space
> @@ -625,13 +627,21 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
>  							      &ntb->vpci_mw_phy[i],
>  							      size);
>  		if (!ntb->vpci_mw_addr[i]) {
> +			ret = -ENOMEM;
>  			dev_err(dev, "Failed to allocate source address\n");
> -			goto err_alloc_mem;
> +			goto err_set_bar;
>  		}
>  	}
>  
>  	return ret;
> +
> +err_set_bar:
> +	pci_epc_clear_bar(ntb->epf->epc,
> +			  ntb->epf->func_no,
> +			  ntb->epf->vfunc_no,
> +			  &ntb->epf->bar[barno]);
>  err_alloc_mem:
> +	epf_ntb_mw_bar_clear(ntb, i);
>  	return ret;
>  }
>  
> @@ -640,12 +650,12 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
>   * @ntb: NTB device that facilitates communication between HOST and vHOST
>   *
>   */
> -static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb)
> +static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
>  {
>  	enum pci_barno barno;
>  	int i;
>  
> -	for (i = 0; i < ntb->num_mws; i++) {
> +	for (i = 0; i < num_mws; i++) {
>  		barno = ntb->epf_ntb_bar[BAR_MW0 + i];
>  		pci_epc_clear_bar(ntb->epf->epc,
>  				  ntb->epf->func_no,
> @@ -774,7 +784,7 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
>  	return 0;
>  
>  err_write_header:
> -	epf_ntb_mw_bar_clear(ntb);
> +	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
>  err_mw_bar_init:
>  	epf_ntb_db_bar_clear(ntb);
>  err_db_bar_init:
> @@ -794,7 +804,7 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
>  static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
>  {
>  	epf_ntb_db_bar_clear(ntb);
> -	epf_ntb_mw_bar_clear(ntb);
> +	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
>  }
>  
>  #define EPF_NTB_R(_name)						\
> -- 
> 2.25.1
>