enic: detect SR-IOV VF type from PCI capability

Read the VF device ID from the SR-IOV PCI capability at probe time to
determine whether the PF is configured for V1, USNIC, or V2 virtual
functions. Store the result in enic->vf_type for use by subsequent
SR-IOV operations.

The VF type is a firmware-configured property (set via UCSM, CIMC,
Intersight etc) that is immutable from the driver's perspective. Only
PFs are probed for this capability; VFs and dynamic vnics skip
detection.

Signed-off-by: Satish Kharat <satishkh@cisco.com>
Link: https://patch.msgid.link/20260401-enic-sriov-v2-prep-v4-3-d5834b2ef1b9@cisco.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/cisco/enic/enic.h b/drivers/net/ethernet/cisco/enic/enic.h
index 366c65d072fc5dcfa91166444a3d9674cf9410be..0fd9cd917132f81ebcd00c490303bfbcc8eb7bf1 100644 (file)
--- a/drivers/net/ethernet/cisco/enic/enic.h
+++ b/drivers/net/ethernet/cisco/enic/enic.h
@@ -225,6 +225,13 @@ struct enic_rq {
        struct page_pool *pool;
 } ____cacheline_aligned;
 
+enum enic_vf_type {
+       ENIC_VF_TYPE_NONE,
+       ENIC_VF_TYPE_V1,
+       ENIC_VF_TYPE_USNIC,
+       ENIC_VF_TYPE_V2,
+};
+
 /* Per-instance private data structure */
 struct enic {
        struct net_device *netdev;
@@ -252,6 +259,7 @@ struct enic {
 #ifdef CONFIG_PCI_IOV
        u16 num_vfs;
 #endif
+       enum enic_vf_type vf_type;
        spinlock_t enic_api_lock;
        bool enic_api_busy;
        struct enic_port_profile *pp;

diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index e16dfbcd2c229ff86f72468fd8c89c86406e88c6..acd05350ec1aa94505fba019e2e738674a8b9ca0 100644 (file)
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -67,6 +67,7 @@
 #define PCI_DEVICE_ID_CISCO_VIC_ENET_DYN     0x0044  /* enet dynamic vnic */
 #define PCI_DEVICE_ID_CISCO_VIC_ENET_VF      0x0071  /* enet SRIOV VF */
 #define PCI_DEVICE_ID_CISCO_VIC_ENET_VF_V2   0x02b7  /* enet SRIOV V2 VF */
+#define PCI_DEVICE_ID_CISCO_VIC_ENET_VF_USNIC 0x00cf /* enet USNIC VF */
 
 /* Supported devices */
 static const struct pci_device_id enic_id_table[] = {
@@ -2621,6 +2622,41 @@ static void enic_iounmap(struct enic *enic)
                        iounmap(enic->bar[i].vaddr);
 }
 
+#ifdef CONFIG_PCI_IOV
+static void enic_sriov_detect_vf_type(struct enic *enic)
+{
+       struct pci_dev *pdev = enic->pdev;
+       int pos;
+       u16 vf_dev_id;
+
+       if (enic_is_sriov_vf(enic) || enic_is_dynamic(enic))
+               return;
+
+       pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
+       if (!pos) {
+               enic->vf_type = ENIC_VF_TYPE_NONE;
+               return;
+       }
+
+       pci_read_config_word(pdev, pos + PCI_SRIOV_VF_DID, &vf_dev_id);
+
+       switch (vf_dev_id) {
+       case PCI_DEVICE_ID_CISCO_VIC_ENET_VF:
+               enic->vf_type = ENIC_VF_TYPE_V1;
+               break;
+       case PCI_DEVICE_ID_CISCO_VIC_ENET_VF_USNIC:
+               enic->vf_type = ENIC_VF_TYPE_USNIC;
+               break;
+       case PCI_DEVICE_ID_CISCO_VIC_ENET_VF_V2:
+               enic->vf_type = ENIC_VF_TYPE_V2;
+               break;
+       default:
+               enic->vf_type = ENIC_VF_TYPE_NONE;
+               break;
+       }
+}
+#endif
+
 static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
        struct device *dev = &pdev->dev;
@@ -2734,6 +2770,7 @@ static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
                        num_pps = enic->num_vfs;
                }
        }
+       enic_sriov_detect_vf_type(enic);
 #endif
 
        /* Allocate structure for port profiles */