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From:   Gautam Dawar <gautam.dawar@amd.com>
To:     <linux-net-drivers@amd.com>, <jasowang@redhat.com>,
        Edward Cree <ecree.xilinx@gmail.com>,
        Martin Habets <habetsm.xilinx@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        "Jakub Kicinski" <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Richard Cochran <richardcochran@gmail.com>,
        <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>
CC:     <eperezma@redhat.com>, <harpreet.anand@amd.com>,
        <tanuj.kamde@amd.com>, <koushik.dutta@amd.com>,
        Gautam Dawar <gautam.dawar@amd.com>
Subject: [PATCH net-next v2 07/14] sfc: implement vdpa device config operations
Date:   Tue, 7 Mar 2023 17:06:09 +0530
Message-ID: <20230307113621.64153-8-gautam.dawar@amd.com>
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vDPA config operations can be broadly categorized in to either
virtqueue operations, device operations or DMA operations.
This patch implements most of the device level config operations.

Signed-off-by: Gautam Dawar <gautam.dawar@amd.com>
---
 drivers/net/ethernet/sfc/ef100_vdpa.h     |  14 +++
 drivers/net/ethernet/sfc/ef100_vdpa_ops.c | 131 ++++++++++++++++++++++
 2 files changed, 145 insertions(+)

diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.h b/drivers/net/ethernet/sfc/ef100_vdpa.h
index 1101b30f56e7..dcf4a8156415 100644
--- a/drivers/net/ethernet/sfc/ef100_vdpa.h
+++ b/drivers/net/ethernet/sfc/ef100_vdpa.h
@@ -20,6 +20,18 @@
 /* Max queue pairs currently supported */
 #define EF100_VDPA_MAX_QUEUES_PAIRS 1
 
+/* Device ID of a virtio net device */
+#define EF100_VDPA_VIRTIO_NET_DEVICE_ID VIRTIO_ID_NET
+
+/* Vendor ID of Xilinx vDPA NIC */
+#define EF100_VDPA_VENDOR_ID  PCI_VENDOR_ID_XILINX
+
+/* Max number of Buffers supported in the virtqueue */
+#define EF100_VDPA_VQ_NUM_MAX_SIZE 512
+
+/* Alignment requirement of the Virtqueue */
+#define EF100_VDPA_VQ_ALIGN 4096
+
 /**
  * enum ef100_vdpa_nic_state - possible states for a vDPA NIC
  *
@@ -60,6 +72,7 @@ enum ef100_vdpa_vq_type {
  * @net_config: virtio_net_config data
  * @mac_address: mac address of interface associated with this vdpa device
  * @mac_configured: true after MAC address is configured
+ * @cfg_cb: callback for config change
  */
 struct ef100_vdpa_nic {
 	struct vdpa_device vdpa_dev;
@@ -75,6 +88,7 @@ struct ef100_vdpa_nic {
 	struct virtio_net_config net_config;
 	u8 *mac_address;
 	bool mac_configured;
+	struct vdpa_callback cfg_cb;
 };
 
 int ef100_vdpa_init(struct efx_probe_data *probe_data);
diff --git a/drivers/net/ethernet/sfc/ef100_vdpa_ops.c b/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
index f1ce011adc43..a2364ef9f492 100644
--- a/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
+++ b/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
@@ -9,12 +9,131 @@
 
 #include <linux/vdpa.h>
 #include "ef100_vdpa.h"
+#include "mcdi_vdpa.h"
 
 static struct ef100_vdpa_nic *get_vdpa_nic(struct vdpa_device *vdev)
 {
 	return container_of(vdev, struct ef100_vdpa_nic, vdpa_dev);
 }
 
+static u32 ef100_vdpa_get_vq_align(struct vdpa_device *vdev)
+{
+	return EF100_VDPA_VQ_ALIGN;
+}
+
+static u64 ef100_vdpa_get_device_features(struct vdpa_device *vdev)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+	u64 features;
+	int rc;
+
+	rc = efx_vdpa_get_features(vdpa_nic->efx,
+				   EF100_VDPA_DEVICE_TYPE_NET, &features);
+	if (rc) {
+		dev_err(&vdev->dev, "%s: MCDI get features error:%d\n",
+			__func__, rc);
+		/* Returning 0 as value of features will lead to failure
+		 * of feature negotiation.
+		 */
+		return 0;
+	}
+
+	features |= BIT_ULL(VIRTIO_NET_F_MAC);
+	return features;
+}
+
+static int ef100_vdpa_set_driver_features(struct vdpa_device *vdev,
+					  u64 features)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+	u64 verify_features;
+	int rc;
+
+	mutex_lock(&vdpa_nic->lock);
+	verify_features = features & ~BIT_ULL(VIRTIO_NET_F_MAC);
+	rc = efx_vdpa_verify_features(vdpa_nic->efx,
+				      EF100_VDPA_DEVICE_TYPE_NET,
+				      verify_features);
+	if (rc) {
+		dev_err(&vdev->dev, "%s: MCDI verify features error:%d\n",
+			__func__, rc);
+		goto err;
+	}
+
+	vdpa_nic->features = features;
+err:
+	mutex_unlock(&vdpa_nic->lock);
+	return rc;
+}
+
+static u64 ef100_vdpa_get_driver_features(struct vdpa_device *vdev)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+
+	return vdpa_nic->features;
+}
+
+static void ef100_vdpa_set_config_cb(struct vdpa_device *vdev,
+				     struct vdpa_callback *cb)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+
+	if (cb)
+		vdpa_nic->cfg_cb = *cb;
+}
+
+static u16 ef100_vdpa_get_vq_num_max(struct vdpa_device *vdev)
+{
+	return EF100_VDPA_VQ_NUM_MAX_SIZE;
+}
+
+static u32 ef100_vdpa_get_device_id(struct vdpa_device *vdev)
+{
+	return EF100_VDPA_VIRTIO_NET_DEVICE_ID;
+}
+
+static u32 ef100_vdpa_get_vendor_id(struct vdpa_device *vdev)
+{
+	return EF100_VDPA_VENDOR_ID;
+}
+
+static size_t ef100_vdpa_get_config_size(struct vdpa_device *vdev)
+{
+	return sizeof(struct virtio_net_config);
+}
+
+static void ef100_vdpa_get_config(struct vdpa_device *vdev,
+				  unsigned int offset,
+				  void *buf, unsigned int len)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+
+	/* Avoid the possibility of wrap-up after the sum exceeds U32_MAX */
+	if (WARN_ON(((u64)offset + len) > sizeof(struct virtio_net_config))) {
+		dev_err(&vdev->dev,
+			"%s: Offset + len exceeds config size\n", __func__);
+		return;
+	}
+	memcpy(buf, (u8 *)&vdpa_nic->net_config + offset, len);
+}
+
+static void ef100_vdpa_set_config(struct vdpa_device *vdev, unsigned int offset,
+				  const void *buf, unsigned int len)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+
+	/* Avoid the possibility of wrap-up after the sum exceeds U32_MAX */
+	if (WARN_ON(((u64)offset + len) > sizeof(vdpa_nic->net_config))) {
+		dev_err(&vdev->dev,
+			"%s: Offset + len exceeds config size\n", __func__);
+		return;
+	}
+
+	memcpy((u8 *)&vdpa_nic->net_config + offset, buf, len);
+	if (is_valid_ether_addr(vdpa_nic->mac_address))
+		vdpa_nic->mac_configured = true;
+}
+
 static void ef100_vdpa_free(struct vdpa_device *vdev)
 {
 	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
@@ -26,5 +145,17 @@ static void ef100_vdpa_free(struct vdpa_device *vdev)
 }
 
 const struct vdpa_config_ops ef100_vdpa_config_ops = {
+	.get_vq_align	     = ef100_vdpa_get_vq_align,
+	.get_device_features = ef100_vdpa_get_device_features,
+	.set_driver_features = ef100_vdpa_set_driver_features,
+	.get_driver_features = ef100_vdpa_get_driver_features,
+	.set_config_cb	     = ef100_vdpa_set_config_cb,
+	.get_vq_num_max      = ef100_vdpa_get_vq_num_max,
+	.get_device_id	     = ef100_vdpa_get_device_id,
+	.get_vendor_id	     = ef100_vdpa_get_vendor_id,
+	.get_config_size     = ef100_vdpa_get_config_size,
+	.get_config	     = ef100_vdpa_get_config,
+	.set_config	     = ef100_vdpa_set_config,
+	.get_generation      = NULL,
 	.free	             = ef100_vdpa_free,
 };
-- 
2.30.1