Re: [PATCH v1 3/3] PCI: Add checks to mellanox_check_broken_intx_masking

[Gavin Shan <gwshan@linux.vnet.ibm.com>]

On Tue, Nov 15, 2016 at 10:00:00AM +0200, Noa Osherovich wrote:
>Mellanox devices were marked as having INTx masking ability broken.
>As a result, the VFIO driver fails to start when more than one device
>function is passed-through to a VM if both have the same INTx pin.
>
>Prior to Connect-IB, Mellanox devices exposed to the operating system
>one PCI function per all ports.
>Starting from Connect-IB, the devices are function-per-port. When
>passing the second function to a VM, VFIO will fail to start.
>
>Exclude ConnectX-4, ConnectX4-Lx and Connect-IB from the list of
>Mellanox devices marked as having broken INTx masking:
>
>- ConnectX-4 and ConnectX4-LX firmware version is checked. If INTx
>  masking is supported, we unmark the broken INTx masking.
>- Connect-IB does not support INTx currently so will not cause any
>  problem.
>
>Fixes: 11e42532ada31 ('PCI: Assume all Mellanox devices have ...')
>Signed-off-by: Noa Osherovich <noaos@mellanox.com>
>Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
>Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>---
> drivers/pci/quirks.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 55 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>index 228a4e8a8aeb..112a5fcad2f5 100644
>--- a/drivers/pci/quirks.c
>+++ b/drivers/pci/quirks.c
>@@ -3192,13 +3192,25 @@ static void quirk_broken_intx_masking(struct pci_dev *dev)
> 	PCI_DEVICE_ID_MELLANOX_CONNECTX2,
> 	PCI_DEVICE_ID_MELLANOX_CONNECTX3,
> 	PCI_DEVICE_ID_MELLANOX_CONNECTX3_PRO,
>-	PCI_DEVICE_ID_MELLANOX_CONNECTIB,
>-	PCI_DEVICE_ID_MELLANOX_CONNECTX4,
>-	PCI_DEVICE_ID_MELLANOX_CONNECTX4_LX
> };
>
>+#define CONNECTX_4_CURR_MAX_MINOR 99
>+#define CONNECTX_4_INTX_SUPPORT_MINOR 14
>+
>+/*
>+ * Checking ConnectX-4/LX FW version to see if it supports legacy interrupts.
>+ * If so, don't mark it as broken.
>+ * FW minor > 99 means older FW version format and no INTx masking support.
>+ * FW minor < 14 means new FW version format and no INTx masking support.
>+ */
> static void mellanox_check_broken_intx_masking(struct pci_dev *pdev)
> {
>+	__be32 __iomem *fw_ver;
>+	u16 fw_major;
>+	u16 fw_minor;
>+	u16 fw_subminor;
>+	u32 fw_maj_min;
>+	u32 fw_sub_min;
> 	int i;
>
> 	for (i = 0; i < ARRAY_SIZE(mellanox_broken_intx_devs); i++) {
>@@ -3207,6 +3219,46 @@ static void mellanox_check_broken_intx_masking(struct pci_dev *pdev)
> 			return;
> 		}
> 	}
>+
>+	/* Getting here means Connect-IB cards and up. Connect-IB has no INTx
>+	 * support so shouldn't be checked further
>+	 */
>+	if (pdev->device == PCI_DEVICE_ID_MELLANOX_CONNECTIB)
>+		return;
>+
>+	if (pdev->device != PCI_DEVICE_ID_MELLANOX_CONNECTX4 &&
>+	    pdev->device != PCI_DEVICE_ID_MELLANOX_CONNECTX4_LX)
>+		return;
>+
>+	/* For ConnectX-4 and ConnectX-4LX, need to check FW support */
>+	if (pci_enable_device_mem(pdev)) {
>+		dev_warn(&pdev->dev, "Can't enable device memory\n");
>+		return;
>+	}
>+
>+	/* Convert from PCI bus to resource space. */
>+	fw_ver = ioremap(pci_resource_start(pdev, 0), 4);
>+	if (!fw_ver) {
>+		dev_warn(&pdev->dev, "Can't map ConnectX-4 initialization segment\n");

pci_disable_device(pdev) is missed.

>+		return;
>+	}
>+
>+	/* Reading from resource space should be 32b aligned */
>+	fw_maj_min = ioread32be(fw_ver);
>+	fw_sub_min = ioread32be(fw_ver + 1);
>+	fw_major = fw_maj_min & 0xffff;
>+	fw_minor = fw_maj_min >> 16;
>+	fw_subminor = fw_sub_min & 0xffff;
>+	if (fw_minor > CONNECTX_4_CURR_MAX_MINOR ||
>+	    fw_minor < CONNECTX_4_INTX_SUPPORT_MINOR) {
>+		dev_warn(&pdev->dev, "ConnectX-4: FW %u.%u.%u doesn't support INTx masking, disabling. Please upgrade FW to %d.14.1100 and up for INTx support\n",
>+			 fw_major, fw_minor, fw_subminor, pdev->device ==
>+			 PCI_DEVICE_ID_MELLANOX_CONNECTX4 ? 12 : 14);
>+		pdev->broken_intx_masking = 1;
>+		pci_disable_device(pdev);

This pci_disable_device() should be called unconditionally
before iounmap();

>+	}
>+
>+	iounmap(fw_ver);
> }
>
> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_MELLANOX, PCI_ANY_ID,

Thanks,
Gavin