Re: [PATCH v2] vdpa: solidrun: Replace deprecated PCI functions

[Stefano Garzarella <sgarzare@xxxxxxxxxx>]

On Mon, Dec 09, 2024 at 12:51:18PM +0100, Philipp Stanner wrote:
> The PCI functions
>
> 	pcim_iomap_regions()
> 	pcim_iounmap_regions()
> 	pcim_iomap_table()
>
> have been deprecated by the PCI subsystem.
>
> Replace these functions with their successors pcim_iomap_region() and
> pcim_iounmap_region().
>
> Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx>
> ---
> Changes in v2:
>  - Fix build warning because of dead variable.
>  - Make "bars_found" a boolean, since only true or false are relevant.
> ---
> drivers/vdpa/solidrun/snet_main.c | 55 ++++++++++++++-----------------
> 1 file changed, 25 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/vdpa/solidrun/snet_main.c b/drivers/vdpa/solidrun/snet_main.c
> index c8b74980dbd1..1b9841698a1a 100644
> --- a/drivers/vdpa/solidrun/snet_main.c
> +++ b/drivers/vdpa/solidrun/snet_main.c
> @@ -556,59 +556,57 @@ static const struct vdpa_config_ops snet_config_ops = {
> static int psnet_open_pf_bar(struct pci_dev *pdev, struct psnet *psnet)
> {
> 	char *name;
> -	int ret, i, mask = 0;
> +	unsigned short i;
> +	bool bars_found = false;
> +	void __iomem *io;

I would suggest to move this declaration (*io) inside the for loop where 
it's used.

> +
> +	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
> +	if (!name)
> +		return -ENOMEM;
> +
> 	/* We don't know which BAR will be used to communicate..
> 	 * We will map every bar with len > 0.
> 	 *
> 	 * Later, we will discover the BAR and unmap all other BARs.
> 	 */
> 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> -		if (pci_resource_len(pdev, i))
> -			mask |= (1 << i);
> +		if (pci_resource_len(pdev, i) == 0)
> +			continue;
> +
> +		io = pcim_iomap_region(pdev, i, name);
> +		if (IS_ERR(io)) {
> +			SNET_ERR(pdev, "Failed to request and map PCI BARs\n");
> +			return PTR_ERR(io);

Now instead of calling pcim_iomap_regions() once, we need to call 
pcim_iomap_region() multiple times.
If one of these fails, should we unmap the ones we mapped before?

Thanks,
Stefano

> +		}
> +
> +		psnet->bars[i] = io;
> +		bars_found = true;
> 	}
>
> 	/* No BAR can be used.. */
> -	if (!mask) {
> +	if (!bars_found) {
> 		SNET_ERR(pdev, "Failed to find a PCI BAR\n");
> 		return -ENODEV;
> 	}
>
> -	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "psnet[%s]-bars", pci_name(pdev));
> -	if (!name)
> -		return -ENOMEM;
> -
> -	ret = pcim_iomap_regions(pdev, mask, name);
> -	if (ret) {
> -		SNET_ERR(pdev, "Failed to request and map PCI BARs\n");
> -		return ret;
> -	}
> -
> -	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> -		if (mask & (1 << i))
> -			psnet->bars[i] = pcim_iomap_table(pdev)[i];
> -	}
> -
> 	return 0;
> }
>
> static int snet_open_vf_bar(struct pci_dev *pdev, struct snet *snet)
> {
> 	char *name;
> -	int ret;
>
> 	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "snet[%s]-bars", pci_name(pdev));
> 	if (!name)
> 		return -ENOMEM;
>
> 	/* Request and map BAR */
> -	ret = pcim_iomap_regions(pdev, BIT(snet->psnet->cfg.vf_bar), name);
> -	if (ret) {
> +	snet->bar = pcim_iomap_region(pdev, snet->psnet->cfg.vf_bar, name);
> +	if (IS_ERR(snet->bar)) {
> 		SNET_ERR(pdev, "Failed to request and map PCI BAR for a VF\n");
> -		return ret;
> +		return PTR_ERR(snet->bar);
> 	}
>
> -	snet->bar = pcim_iomap_table(pdev)[snet->psnet->cfg.vf_bar];
> -
> 	return 0;
> }
>
> @@ -656,15 +654,12 @@ static int psnet_detect_bar(struct psnet *psnet, u32 off)
>
> static void psnet_unmap_unused_bars(struct pci_dev *pdev, struct psnet *psnet)
> {
> -	int i, mask = 0;
> +	unsigned short i;
>
> 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
> 		if (psnet->bars[i] && i != psnet->barno)
> -			mask |= (1 << i);
> +			pcim_iounmap_region(pdev, i);
> 	}
> -
> -	if (mask)
> -		pcim_iounmap_regions(pdev, mask);
> }
>
> /* Read SNET config from PCI BAR */
> --
> 2.47.1