net: ena: Add device reload capability through devlink

Adding basic devlink capability support of reloading the driver.
This capability is required to support driver init type
devlink params (DEVLINK_PARAM_CMODE_DRIVERINIT). Such params
require reloading of the driver (destroy/restore sequence).
The reloading is done by the devlink framework using the
hooks provided by the driver.

Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-4-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
index 98dc62174a40613684ddcc1c73507bf18a5e2a75..112a3994bc8545ca415c02857be69c528933602f 100644 (file)
--- a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
+++ b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
@@ -57,6 +57,7 @@ ena_ethtool.c       ethtool callbacks.
 ena_xdp.[ch]        XDP files
 ena_pci_id_tbl.h    Supported device IDs.
 ena_phc.[ch]        PTP hardware clock infrastructure (see `PHC`_ for more info)
+ena_devlink.[ch]    devlink files.
 =================   ======================================================
 
 Management Interface:
@@ -269,6 +270,18 @@ RSS
 - The user can provide a hash key, hash function, and configure the
   indirection table through `ethtool(8)`.
 
+DEVLINK SUPPORT
+===============
+.. _`devlink`: https://www.kernel.org/doc/html/latest/networking/devlink/index.html
+
+`devlink`_ supports reloading the driver and initiating re-negotiation with the ENA device
+
+.. code-block:: shell
+
+  sudo devlink dev reload pci/<domain:bus:slot.function>
+  # for example:
+  sudo devlink dev reload pci/0000:00:06.0
+
 DATA PATH
 =========
 

diff --git a/drivers/net/ethernet/amazon/Kconfig b/drivers/net/ethernet/amazon/Kconfig
index 8d61bc62e295aee260260b9484e1a83a38a0c323..95dcc3969f0c1081d315d4d853062635543777b5 100644 (file)
--- a/drivers/net/ethernet/amazon/Kconfig
+++ b/drivers/net/ethernet/amazon/Kconfig
@@ -21,6 +21,7 @@ config ENA_ETHERNET
        depends on PCI_MSI && !CPU_BIG_ENDIAN
        depends on PTP_1588_CLOCK_OPTIONAL
        select DIMLIB
+       select NET_DEVLINK
        help
          This driver supports Elastic Network Adapter (ENA)"
 

diff --git a/drivers/net/ethernet/amazon/ena/Makefile b/drivers/net/ethernet/amazon/ena/Makefile
index 8c874177468fe70d3376d7d2cb36ab31dcdeedaa..4b6511db873e041a046ad7723f66a9bbb437d779 100644 (file)
--- a/drivers/net/ethernet/amazon/ena/Makefile
+++ b/drivers/net/ethernet/amazon/ena/Makefile
@@ -5,4 +5,4 @@
 
 obj-$(CONFIG_ENA_ETHERNET) += ena.o
 
-ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o ena_xdp.o ena_phc.o
+ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o ena_xdp.o ena_phc.o ena_devlink.o

diff --git a/drivers/net/ethernet/amazon/ena/ena_devlink.c b/drivers/net/ethernet/amazon/ena/ena_devlink.c
new file mode 100644 (file)
index 0000000..db56916
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_devlink.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) Amazon.com, Inc. or its affiliates.
+ * All rights reserved.
+ */
+
+#include "linux/pci.h"
+#include "ena_devlink.h"
+
+static int ena_devlink_reload_down(struct devlink *devlink,
+                                  bool netns_change,
+                                  enum devlink_reload_action action,
+                                  enum devlink_reload_limit limit,
+                                  struct netlink_ext_ack *extack)
+{
+       struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+
+       if (netns_change) {
+               NL_SET_ERR_MSG_MOD(extack,
+                                  "Namespace change is not supported");
+               return -EOPNOTSUPP;
+       }
+
+       rtnl_lock();
+       ena_destroy_device(adapter, false);
+       rtnl_unlock();
+
+       return 0;
+}
+
+static int ena_devlink_reload_up(struct devlink *devlink,
+                                enum devlink_reload_action action,
+                                enum devlink_reload_limit limit,
+                                u32 *actions_performed,
+                                struct netlink_ext_ack *extack)
+{
+       struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+       int err = 0;
+
+       rtnl_lock();
+       /* Check that no other routine initialized the device (e.g.
+        * ena_fw_reset_device()). Also we're under devlink_mutex here,
+        * so devlink isn't freed under our feet.
+        */
+       if (!test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
+               err = ena_restore_device(adapter);
+
+       rtnl_unlock();
+
+       if (!err)
+               *actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
+
+       return err;
+}
+
+static const struct devlink_ops ena_devlink_ops = {
+       .reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
+       .reload_down    = ena_devlink_reload_down,
+       .reload_up      = ena_devlink_reload_up,
+};
+
+struct devlink *ena_devlink_alloc(struct ena_adapter *adapter)
+{
+       struct device *dev = &adapter->pdev->dev;
+       struct devlink *devlink;
+
+       devlink = devlink_alloc(&ena_devlink_ops,
+                               sizeof(struct ena_adapter *),
+                               dev);
+       if (!devlink) {
+               netdev_err(adapter->netdev,
+                          "Failed to allocate devlink struct\n");
+               return NULL;
+       }
+
+       ENA_DEVLINK_PRIV(devlink) = adapter;
+       adapter->devlink = devlink;
+
+       return devlink;
+}
+
+void ena_devlink_free(struct devlink *devlink)
+{
+       devlink_free(devlink);
+}
+
+void ena_devlink_register(struct devlink *devlink, struct device *dev)
+{
+       devlink_register(devlink);
+}
+
+void ena_devlink_unregister(struct devlink *devlink)
+{
+       devlink_unregister(devlink);
+}

diff --git a/drivers/net/ethernet/amazon/ena/ena_devlink.h b/drivers/net/ethernet/amazon/ena/ena_devlink.h
new file mode 100644 (file)
index 0000000..cb1a5f2
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_devlink.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) Amazon.com, Inc. or its affiliates.
+ * All rights reserved.
+ */
+#ifndef DEVLINK_H
+#define DEVLINK_H
+
+#include "ena_netdev.h"
+#include <net/devlink.h>
+
+#define ENA_DEVLINK_PRIV(devlink) \
+       (*(struct ena_adapter **)devlink_priv(devlink))
+
+struct devlink *ena_devlink_alloc(struct ena_adapter *adapter);
+void ena_devlink_free(struct devlink *devlink);
+void ena_devlink_register(struct devlink *devlink, struct device *dev);
+void ena_devlink_unregister(struct devlink *devlink);
+
+#endif /* DEVLINK_H */

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 14a85916464b6e74b84200f4604a7650d96307ab..ab88895b874e61f2d68600aa5ca816127032675b 100644 (file)
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -21,6 +21,8 @@
 
 #include "ena_phc.h"
 
+#include "ena_devlink.h"
+
 MODULE_AUTHOR("Amazon.com, Inc. or its affiliates");
 MODULE_DESCRIPTION(DEVICE_NAME);
 MODULE_LICENSE("GPL");
@@ -41,8 +43,6 @@ MODULE_DEVICE_TABLE(pci, ena_pci_tbl);
 
 static int ena_rss_init_default(struct ena_adapter *adapter);
 static void check_for_admin_com_state(struct ena_adapter *adapter);
-static int ena_destroy_device(struct ena_adapter *adapter, bool graceful);
-static int ena_restore_device(struct ena_adapter *adapter);
 
 static void ena_tx_timeout(struct net_device *dev, unsigned int txqueue)
 {
@@ -3240,7 +3240,7 @@ err_disable_msix:
        return rc;
 }
 
-static int ena_destroy_device(struct ena_adapter *adapter, bool graceful)
+int ena_destroy_device(struct ena_adapter *adapter, bool graceful)
 {
        struct net_device *netdev = adapter->netdev;
        struct ena_com_dev *ena_dev = adapter->ena_dev;
@@ -3291,7 +3291,7 @@ static int ena_destroy_device(struct ena_adapter *adapter, bool graceful)
        return rc;
 }
 
-static int ena_restore_device(struct ena_adapter *adapter)
+int ena_restore_device(struct ena_adapter *adapter)
 {
        struct ena_com_dev_get_features_ctx get_feat_ctx;
        struct ena_com_dev *ena_dev = adapter->ena_dev;
@@ -3877,6 +3877,7 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
        struct ena_adapter *adapter;
        struct net_device *netdev;
        static int adapters_found;
+       struct devlink *devlink;
        u32 max_num_io_queues;
        bool wd_state;
        int bars, rc;
@@ -3960,12 +3961,20 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
                goto err_metrics_destroy;
        }
 
+       /* Need to do this before ena_device_init */
+       devlink = ena_devlink_alloc(adapter);
+       if (!devlink) {
+               netdev_err(netdev, "ena_devlink_alloc failed\n");
+               rc = -ENOMEM;
+               goto err_metrics_destroy;
+       }
+
        rc = ena_device_init(adapter, pdev, &get_feat_ctx, &wd_state);
        if (rc) {
                dev_err(&pdev->dev, "ENA device init failed\n");
                if (rc == -ETIME)
                        rc = -EPROBE_DEFER;
-               goto err_metrics_destroy;
+               goto ena_devlink_destroy;
        }
 
        /* Initial TX and RX interrupt delay. Assumes 1 usec granularity.
@@ -4070,6 +4079,12 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
        adapters_found++;
 
+       /* From this point, the devlink device is visible to users.
+        * Perform the registration last to ensure that all the resources
+        * are available and that the netdevice is registered.
+        */
+       ena_devlink_register(devlink, &pdev->dev);
+
        return 0;
 
 err_rss:
@@ -4086,6 +4101,8 @@ err_worker_destroy:
 err_device_destroy:
        ena_com_delete_host_info(ena_dev);
        ena_com_admin_destroy(ena_dev);
+ena_devlink_destroy:
+       ena_devlink_free(devlink);
 err_metrics_destroy:
        ena_com_delete_customer_metrics_buffer(ena_dev);
 err_free_phc:
@@ -4132,6 +4149,9 @@ static void __ena_shutoff(struct pci_dev *pdev, bool shutdown)
 
        ena_phc_free(adapter);
 
+       ena_devlink_unregister(adapter->devlink);
+       ena_devlink_free(adapter->devlink);
+
        if (shutdown) {
                netif_device_detach(netdev);
                dev_close(netdev);

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index 7867cd7f25bc1cb9fefa172c21b9514b59e04e29..a732a19ea97ba11a032692db2d85d47c1d3958a1 100644 (file)
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -16,6 +16,7 @@
 #include <linux/skbuff.h>
 #include <net/xdp.h>
 #include <uapi/linux/bpf.h>
+#include <net/devlink.h>
 
 #include "ena_com.h"
 #include "ena_eth_com.h"
@@ -387,6 +388,8 @@ struct ena_adapter {
        struct bpf_prog *xdp_bpf_prog;
        u32 xdp_first_ring;
        u32 xdp_num_queues;
+
+       struct devlink *devlink;
 };
 
 void ena_set_ethtool_ops(struct net_device *netdev);
@@ -416,6 +419,8 @@ static inline void ena_reset_device(struct ena_adapter *adapter,
        set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
 }
 
+int ena_destroy_device(struct ena_adapter *adapter, bool graceful);
+int ena_restore_device(struct ena_adapter *adapter);
 int handle_invalid_req_id(struct ena_ring *ring, u16 req_id,
                          struct ena_tx_buffer *tx_info, bool is_xdp);