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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <whzxo7v7ocomwvx2onrccrrnfc7eg5g5yeusoifmmflaiawaa6@xylztblydibz>
Date: Mon, 9 Dec 2024 14:31:05 +0100
From: Stefano Garzarella <sgarzare@...hat.com>
To: Philipp Stanner <pstanner@...hat.com>
Cc: Alvaro Karsz <alvaro.karsz@...id-run.com>, 
	"Michael S. Tsirkin" <mst@...hat.com>, Jason Wang <jasowang@...hat.com>, 
	Xuan Zhuo <xuanzhuo@...ux.alibaba.com>, Eugenio Pérez <eperezma@...hat.com>, 
	virtualization@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] vdpa: solidrun: Replace deprecated PCI functions

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@...hat.com>
>---
>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
>