vdpa/octeon_ep: read vendor-specific PCI capability

Added support to read the vendor-specific PCI capability to identify the
type of device being emulated.

Reviewed-by: Dan Carpenter <[email protected]>
Acked-by: Jason Wang <[email protected]>
Signed-off-by: Shijith Thotton <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

Author: Shijith Thotton

drivers/vdpa/octeon_ep/octep_vdpa.h

@@ -8,6 +8,7 @@
 #include <linux/pci_regs.h>
 #include <linux/vdpa.h>
 #include <linux/virtio_pci_modern.h>
+#include <uapi/linux/virtio_crypto.h>
 #include <uapi/linux/virtio_net.h>
 #include <uapi/linux/virtio_blk.h>
 #include <uapi/linux/virtio_config.h>
@@ -52,6 +53,24 @@ struct octep_vring_info {
 	phys_addr_t notify_pa;
 };
 
+enum octep_pci_vndr_cfg_type {
+	OCTEP_PCI_VNDR_CFG_TYPE_VIRTIO_ID,
+	OCTEP_PCI_VNDR_CFG_TYPE_MAX,
+};
+
+struct octep_pci_vndr_data {
+	struct virtio_pci_vndr_data hdr;
+	u8 id;
+	u8 bar;
+	union {
+		u64 data;
+		struct {
+			u32 offset;
+			u32 length;
+		};
+	};
+};
+
 struct octep_hw {
 	struct pci_dev *pdev;
 	u8 __iomem *base[PCI_STD_NUM_BARS];
@@ -69,6 +88,7 @@ struct octep_hw {
 	u32 config_size;
 	int nb_irqs;
 	int *irqs;
+	u8 dev_id;
 };
 
 u8 octep_hw_get_status(struct octep_hw *oct_hw);

drivers/vdpa/octeon_ep/octep_vdpa_hw.c

@@ -2,6 +2,7 @@
 /* Copyright (C) 2024 Marvell. */
 
 #include <linux/iopoll.h>
+#include <linux/build_bug.h>
 
 #include "octep_vdpa.h"
 
@@ -358,7 +359,14 @@ u16 octep_get_vq_size(struct octep_hw *oct_hw)
 
 static u32 octep_get_config_size(struct octep_hw *oct_hw)
 {
-	return sizeof(struct virtio_net_config);
+	switch (oct_hw->dev_id) {
+	case VIRTIO_ID_NET:
+		return sizeof(struct virtio_net_config);
+	case VIRTIO_ID_CRYPTO:
+		return sizeof(struct virtio_crypto_config);
+	default:
+		return 0;
+	}
 }
 
 static void __iomem *octep_get_cap_addr(struct octep_hw *oct_hw, struct virtio_pci_cap *cap)
@@ -416,8 +424,25 @@ static int octep_pci_signature_verify(struct octep_hw *oct_hw)
 	return 0;
 }
 
+static void octep_vndr_data_process(struct octep_hw *oct_hw,
+				    struct octep_pci_vndr_data *vndr_data)
+{
+	BUILD_BUG_ON(sizeof(struct octep_pci_vndr_data) % 4 != 0);
+
+	switch (vndr_data->id) {
+	case OCTEP_PCI_VNDR_CFG_TYPE_VIRTIO_ID:
+		oct_hw->dev_id = (u8)vndr_data->data;
+		break;
+	default:
+		dev_err(&oct_hw->pdev->dev, "Invalid vendor data id %u\n",
+			vndr_data->id);
+		break;
+	}
+}
+
 int octep_hw_caps_read(struct octep_hw *oct_hw, struct pci_dev *pdev)
 {
+	struct octep_pci_vndr_data vndr_data;
 	struct octep_mbox __iomem *mbox;
 	struct device *dev = &pdev->dev;
 	struct virtio_pci_cap cap;
@@ -466,6 +491,15 @@ int octep_hw_caps_read(struct octep_hw *oct_hw, struct pci_dev *pdev)
 		case VIRTIO_PCI_CAP_ISR_CFG:
 			oct_hw->isr = octep_get_cap_addr(oct_hw, &cap);
 			break;
+		case VIRTIO_PCI_CAP_VENDOR_CFG:
+			octep_pci_caps_read(oct_hw, &vndr_data, sizeof(vndr_data), pos);
+			if (vndr_data.hdr.vendor_id != PCI_VENDOR_ID_CAVIUM) {
+				dev_err(dev, "Invalid vendor data\n");
+				return -EINVAL;
+			}
+
+			octep_vndr_data_process(oct_hw, &vndr_data);
+			break;
 		}
 
 		pos = cap.cap_next;

drivers/vdpa/octeon_ep/octep_vdpa_main.c

@@ -302,7 +302,9 @@ static u32 octep_vdpa_get_generation(struct vdpa_device *vdpa_dev)
 
 static u32 octep_vdpa_get_device_id(struct vdpa_device *vdpa_dev)
 {
-	return VIRTIO_ID_NET;
+	struct octep_hw *oct_hw = vdpa_to_octep_hw(vdpa_dev);
+
+	return oct_hw->dev_id;
 }
 
 static u32 octep_vdpa_get_vendor_id(struct vdpa_device *vdpa_dev)