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

[Frank Li]

> -----Original Message-----
> From: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> Sent: Friday, June 24, 2022 4:46 AM
> To: linux-kernel@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx
> Cc: Frank Li <frank.li@xxxxxxx>; jdmason@xxxxxxxx; kishon@xxxxxx;
> lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx; bhelgaas@xxxxxxxxxx
> Subject: [PATCH -next] PCI: endpoint: pci-epf-vntb: fix error handle in
> epf_ntb_mw_bar_init()
> 
> 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.
> 
> Fixes: ff32fac00d97 ("NTB: EPF: support NTB transfer between PCI RC and EP
> connection")
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> ---
>  drivers/pci/endpoint/functions/pci-epf-vntb.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index ebf7e243eefa..d8ed640c16c4 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
> @@ -625,6 +627,11 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
>  							      &ntb-
> >vpci_mw_phy[i],
>  							      size);
>  		if (!ntb->vpci_mw_addr[i]) {
> +			pci_epc_clear_bar(ntb->epf->epc,
> +					  ntb->epf->func_no,
> +					  ntb->epf->vfunc_no,
> +					  &ntb->epf->bar[barno]);
> +			ret = -ENOMEM;

This function move to goto and keep consistent of error handle. 
 
Suggest: 
	Goto err_set_bar

	....
Error_set_bar:
	Pci_epc_clear_bar();

>  			dev_err(dev, "Failed to allocate source address\n");
>  			goto err_alloc_mem;
>  		}
> @@ -632,6 +639,7 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
> 
>  	return ret;
>  err_alloc_mem:
> +	epf_ntb_mw_bar_clear(ntb, i);
>  	return ret;
>  }
> 
> @@ -640,12 +648,12 @@ 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 +782,7 @@ 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 +802,7 @@ 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