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From:   Gautam Dawar <gautam.dawar@amd.com>
To:     <linux-net-drivers@amd.com>, <netdev@vger.kernel.org>,
        <jasowang@redhat.com>, <eperezma@redhat.com>
CC:     <tanuj.kamde@amd.com>, <Koushik.Dutta@amd.com>,
        <harpreet.anand@amd.com>, Gautam Dawar <gautam.dawar@amd.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>, <linux-kernel@vger.kernel.org>
Subject: [PATCH net-next 08/11] sfc: implement device status related vdpa config operations
Date:   Wed, 7 Dec 2022 20:24:24 +0530
Message-ID: <20221207145428.31544-9-gautam.dawar@amd.com>
In-Reply-To: <20221207145428.31544-1-gautam.dawar@amd.com>
References: <20221207145428.31544-1-gautam.dawar@amd.com>
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vDPA config opertions to handle get/set device status and device
reset have been implemented.

Signed-off-by: Gautam Dawar <gautam.dawar@amd.com>
---
 drivers/net/ethernet/sfc/ef100_vdpa.c     |   7 +-
 drivers/net/ethernet/sfc/ef100_vdpa.h     |   1 +
 drivers/net/ethernet/sfc/ef100_vdpa_ops.c | 133 ++++++++++++++++++++++
 3 files changed, 140 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.c b/drivers/net/ethernet/sfc/ef100_vdpa.c
index 04d64bfe3c93..80bca281a748 100644
--- a/drivers/net/ethernet/sfc/ef100_vdpa.c
+++ b/drivers/net/ethernet/sfc/ef100_vdpa.c
@@ -225,9 +225,14 @@ static int vdpa_allocate_vis(struct efx_nic *efx, unsigned int *allocated_vis)
 
 static void ef100_vdpa_delete(struct efx_nic *efx)
 {
+	struct vdpa_device *vdpa_dev;
+
 	if (efx->vdpa_nic) {
+		vdpa_dev = &efx->vdpa_nic->vdpa_dev;
+		ef100_vdpa_reset(vdpa_dev);
+
 		/* replace with _vdpa_unregister_device later */
-		put_device(&efx->vdpa_nic->vdpa_dev.dev);
+		put_device(&vdpa_dev->dev);
 		efx->vdpa_nic = NULL;
 	}
 	efx_mcdi_free_vis(efx);
diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.h b/drivers/net/ethernet/sfc/ef100_vdpa.h
index a33edd6dda12..1b0bbba88154 100644
--- a/drivers/net/ethernet/sfc/ef100_vdpa.h
+++ b/drivers/net/ethernet/sfc/ef100_vdpa.h
@@ -186,6 +186,7 @@ int ef100_vdpa_add_filter(struct ef100_vdpa_nic *vdpa_nic,
 			  enum ef100_vdpa_mac_filter_type type);
 int ef100_vdpa_irq_vectors_alloc(struct pci_dev *pci_dev, u16 nvqs);
 void ef100_vdpa_irq_vectors_free(void *data);
+int ef100_vdpa_reset(struct vdpa_device *vdev);
 
 static inline bool efx_vdpa_is_little_endian(struct ef100_vdpa_nic *vdpa_nic)
 {
diff --git a/drivers/net/ethernet/sfc/ef100_vdpa_ops.c b/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
index 132ddb4a647b..718b67f6da90 100644
--- a/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
+++ b/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
@@ -251,6 +251,62 @@ static bool is_qid_invalid(struct ef100_vdpa_nic *vdpa_nic, u16 idx,
 	return false;
 }
 
+static void ef100_reset_vdpa_device(struct ef100_vdpa_nic *vdpa_nic)
+{
+	int i;
+
+	WARN_ON(!mutex_is_locked(&vdpa_nic->lock));
+
+	if (!vdpa_nic->status)
+		return;
+
+	vdpa_nic->vdpa_state = EF100_VDPA_STATE_INITIALIZED;
+	vdpa_nic->status = 0;
+	vdpa_nic->features = 0;
+	for (i = 0; i < (vdpa_nic->max_queue_pairs * 2); i++)
+		reset_vring(vdpa_nic, i);
+}
+
+/* May be called under the rtnl lock */
+int ef100_vdpa_reset(struct vdpa_device *vdev)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+
+	/* vdpa device can be deleted anytime but the bar_config
+	 * could still be vdpa and hence efx->state would be STATE_VDPA.
+	 * Accordingly, ensure vdpa device exists before reset handling
+	 */
+	if (!vdpa_nic)
+		return -ENODEV;
+
+	mutex_lock(&vdpa_nic->lock);
+	ef100_reset_vdpa_device(vdpa_nic);
+	mutex_unlock(&vdpa_nic->lock);
+	return 0;
+}
+
+static int start_vdpa_device(struct ef100_vdpa_nic *vdpa_nic)
+{
+	int rc = 0;
+	int i, j;
+
+	for (i = 0; i < (vdpa_nic->max_queue_pairs * 2); i++) {
+		if (can_create_vring(vdpa_nic, i)) {
+			rc = create_vring(vdpa_nic, i);
+			if (rc)
+				goto clear_vring;
+		}
+	}
+	vdpa_nic->vdpa_state = EF100_VDPA_STATE_STARTED;
+	return rc;
+
+clear_vring:
+	for (j = 0; j < i; j++)
+		if (vdpa_nic->vring[j].vring_created)
+			delete_vring(vdpa_nic, j);
+	return rc;
+}
+
 static int ef100_vdpa_set_vq_address(struct vdpa_device *vdev,
 				     u16 idx, u64 desc_area, u64 driver_area,
 				     u64 device_area)
@@ -568,6 +624,80 @@ static u32 ef100_vdpa_get_vendor_id(struct vdpa_device *vdev)
 	return EF100_VDPA_VENDOR_ID;
 }
 
+static u8 ef100_vdpa_get_status(struct vdpa_device *vdev)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+	u8 status;
+
+	mutex_lock(&vdpa_nic->lock);
+	status = vdpa_nic->status;
+	mutex_unlock(&vdpa_nic->lock);
+	return status;
+}
+
+static void ef100_vdpa_set_status(struct vdpa_device *vdev, u8 status)
+{
+	struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
+	u8 new_status;
+	int rc;
+
+	mutex_lock(&vdpa_nic->lock);
+	if (!status) {
+		dev_info(&vdev->dev,
+			 "%s: Status received is 0. Device reset being done\n",
+			 __func__);
+		ef100_reset_vdpa_device(vdpa_nic);
+		goto unlock_return;
+	}
+	new_status = status & ~vdpa_nic->status;
+	if (new_status == 0) {
+		dev_info(&vdev->dev,
+			 "%s: New status same as current status\n", __func__);
+		goto unlock_return;
+	}
+	if (new_status & VIRTIO_CONFIG_S_FAILED) {
+		ef100_reset_vdpa_device(vdpa_nic);
+		goto unlock_return;
+	}
+
+	if (new_status & VIRTIO_CONFIG_S_ACKNOWLEDGE &&
+	    vdpa_nic->vdpa_state == EF100_VDPA_STATE_INITIALIZED) {
+		vdpa_nic->status |= VIRTIO_CONFIG_S_ACKNOWLEDGE;
+		new_status &= ~VIRTIO_CONFIG_S_ACKNOWLEDGE;
+	}
+	if (new_status & VIRTIO_CONFIG_S_DRIVER &&
+	    vdpa_nic->vdpa_state == EF100_VDPA_STATE_INITIALIZED) {
+		vdpa_nic->status |= VIRTIO_CONFIG_S_DRIVER;
+		new_status &= ~VIRTIO_CONFIG_S_DRIVER;
+	}
+	if (new_status & VIRTIO_CONFIG_S_FEATURES_OK &&
+	    vdpa_nic->vdpa_state == EF100_VDPA_STATE_INITIALIZED) {
+		vdpa_nic->status |= VIRTIO_CONFIG_S_FEATURES_OK;
+		vdpa_nic->vdpa_state = EF100_VDPA_STATE_NEGOTIATED;
+		new_status &= ~VIRTIO_CONFIG_S_FEATURES_OK;
+	}
+	if (new_status & VIRTIO_CONFIG_S_DRIVER_OK &&
+	    vdpa_nic->vdpa_state == EF100_VDPA_STATE_NEGOTIATED) {
+		vdpa_nic->status |= VIRTIO_CONFIG_S_DRIVER_OK;
+		rc = start_vdpa_device(vdpa_nic);
+		if (rc) {
+			dev_err(&vdpa_nic->vdpa_dev.dev,
+				"%s: vDPA device failed:%d\n", __func__, rc);
+			vdpa_nic->status &= ~VIRTIO_CONFIG_S_DRIVER_OK;
+			goto unlock_return;
+		}
+		new_status &= ~VIRTIO_CONFIG_S_DRIVER_OK;
+	}
+	if (new_status) {
+		dev_warn(&vdev->dev,
+			 "%s: Mismatch Status: %x & State: %u\n",
+			 __func__, new_status, vdpa_nic->vdpa_state);
+	}
+
+unlock_return:
+	mutex_unlock(&vdpa_nic->lock);
+}
+
 static size_t ef100_vdpa_get_config_size(struct vdpa_device *vdev)
 {
 	return sizeof(struct virtio_net_config);
@@ -640,6 +770,9 @@ const struct vdpa_config_ops ef100_vdpa_config_ops = {
 	.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_status	     = ef100_vdpa_get_status,
+	.set_status	     = ef100_vdpa_set_status,
+	.reset               = ef100_vdpa_reset,
 	.get_config_size     = ef100_vdpa_get_config_size,
 	.get_config	     = ef100_vdpa_get_config,
 	.set_config	     = ef100_vdpa_set_config,
-- 
2.30.1