net: ionic: Create an auxiliary device for rdma driver

To support RDMA capable ethernet device, create an auxiliary device in
the ionic Ethernet driver. The RDMA device is modeled as an auxiliary
device to the Ethernet device.

Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
Link: https://patch.msgid.link/20250903061606.4139957-2-abhijit.gangurde@amd.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/Documentation/networking/device_drivers/ethernet/pensando/ionic.rst b/Documentation/networking/device_drivers/ethernet/pensando/ionic.rst
index 05fe2b11bb18834cade782b1426f7c2991de42b8..a0029b6db31e595ff63a1427a27cc1c5b17b0212 100644 (file)
--- a/Documentation/networking/device_drivers/ethernet/pensando/ionic.rst
+++ b/Documentation/networking/device_drivers/ethernet/pensando/ionic.rst
@@ -13,6 +13,7 @@ Contents
 - Identifying the Adapter
 - Enabling the driver
 - Configuring the driver
+- RDMA Support via Auxiliary Device
 - Statistics
 - Support
 
@@ -105,6 +106,15 @@ XDP
 Support for XDP includes the basics, plus Jumbo frames, Redirect and
 ndo_xmit.  There is no current support for zero-copy sockets or HW offload.
 
+RDMA Support via Auxiliary Device
+=================================
+
+The ionic driver supports RDMA (Remote Direct Memory Access) functionality
+through the Linux auxiliary device framework when advertised by the firmware.
+RDMA capability is detected during device initialization, and if supported,
+the ethernet driver will create an auxiliary device that allows the RDMA
+driver to bind and provide InfiniBand/RoCE functionality.
+
 Statistics
 ==========
 

diff --git a/drivers/net/ethernet/pensando/Kconfig b/drivers/net/ethernet/pensando/Kconfig
index 01fe76786f771a7d3e6d9688ca77fb6ad057fe52..c99758adf3ad73c30cbac4762a87bcdb2adae54f 100644 (file)
--- a/drivers/net/ethernet/pensando/Kconfig
+++ b/drivers/net/ethernet/pensando/Kconfig
@@ -24,6 +24,7 @@ config IONIC
        select NET_DEVLINK
        select DIMLIB
        select PAGE_POOL
+       select AUXILIARY_BUS
        help
          This enables the support for the Pensando family of Ethernet
          adapters.  More specific information on this driver can be

diff --git a/drivers/net/ethernet/pensando/ionic/Makefile b/drivers/net/ethernet/pensando/ionic/Makefile
index 4e7642a2d25fe3505ccf0386bf4cf0ac114844d4..a598972fef41678d6926c347f0c0043075a6495b 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/Makefile
+++ b/drivers/net/ethernet/pensando/ionic/Makefile
@@ -5,5 +5,5 @@ obj-$(CONFIG_IONIC) := ionic.o
 
 ionic-y := ionic_main.o ionic_bus_pci.o ionic_devlink.o ionic_dev.o \
           ionic_debugfs.o ionic_lif.o ionic_rx_filter.o ionic_ethtool.o \
-          ionic_txrx.o ionic_stats.o ionic_fw.o
+          ionic_txrx.o ionic_stats.o ionic_fw.o ionic_aux.o
 ionic-$(CONFIG_PTP_1588_CLOCK) += ionic_phc.o

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_api.h b/drivers/net/ethernet/pensando/ionic/ionic_api.h
new file mode 100644 (file)
index 0000000..f9fcd1b
--- /dev/null
+++ b/drivers/net/ethernet/pensando/ionic/ionic_api.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2018-2025, Advanced Micro Devices, Inc. */
+
+#ifndef _IONIC_API_H_
+#define _IONIC_API_H_
+
+#include <linux/auxiliary_bus.h>
+
+/**
+ * struct ionic_aux_dev - Auxiliary device information
+ * @lif:        Logical interface
+ * @idx:        Index identifier
+ * @adev:       Auxiliary device
+ */
+struct ionic_aux_dev {
+       struct ionic_lif *lif;
+       int idx;
+       struct auxiliary_device adev;
+};
+
+#endif /* _IONIC_API_H_ */

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_aux.c b/drivers/net/ethernet/pensando/ionic/ionic_aux.c
new file mode 100644 (file)
index 0000000..f3c2a52
--- /dev/null
+++ b/drivers/net/ethernet/pensando/ionic/ionic_aux.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2018-2025, Advanced Micro Devices, Inc. */
+
+#include <linux/kernel.h>
+#include "ionic.h"
+#include "ionic_lif.h"
+#include "ionic_aux.h"
+
+static DEFINE_IDA(aux_ida);
+
+static void ionic_auxbus_release(struct device *dev)
+{
+       struct ionic_aux_dev *ionic_adev;
+
+       ionic_adev = container_of(dev, struct ionic_aux_dev, adev.dev);
+       ida_free(&aux_ida, ionic_adev->adev.id);
+       kfree(ionic_adev);
+}
+
+int ionic_auxbus_register(struct ionic_lif *lif)
+{
+       struct ionic_aux_dev *ionic_adev;
+       struct auxiliary_device *aux_dev;
+       int err, id;
+
+       if (!(le64_to_cpu(lif->ionic->ident.lif.capabilities) & IONIC_LIF_CAP_RDMA))
+               return 0;
+
+       ionic_adev = kzalloc(sizeof(*ionic_adev), GFP_KERNEL);
+       if (!ionic_adev)
+               return -ENOMEM;
+
+       aux_dev = &ionic_adev->adev;
+
+       id = ida_alloc(&aux_ida, GFP_KERNEL);
+       if (id < 0) {
+               dev_err(lif->ionic->dev, "Failed to allocate aux id: %d\n", id);
+               kfree(ionic_adev);
+               return id;
+       }
+
+       aux_dev->id = id;
+       aux_dev->name = "rdma";
+       aux_dev->dev.parent = &lif->ionic->pdev->dev;
+       aux_dev->dev.release = ionic_auxbus_release;
+       ionic_adev->lif = lif;
+       err = auxiliary_device_init(aux_dev);
+       if (err) {
+               dev_err(lif->ionic->dev, "Failed to initialize %s aux device: %d\n",
+                       aux_dev->name, err);
+               ida_free(&aux_ida, id);
+               kfree(ionic_adev);
+               return err;
+       }
+
+       err = auxiliary_device_add(aux_dev);
+       if (err) {
+               dev_err(lif->ionic->dev, "Failed to add %s aux device: %d\n",
+                       aux_dev->name, err);
+               auxiliary_device_uninit(aux_dev);
+               return err;
+       }
+
+       lif->ionic_adev = ionic_adev;
+       return 0;
+}
+
+void ionic_auxbus_unregister(struct ionic_lif *lif)
+{
+       mutex_lock(&lif->adev_lock);
+       if (!lif->ionic_adev)
+               goto out;
+
+       auxiliary_device_delete(&lif->ionic_adev->adev);
+       auxiliary_device_uninit(&lif->ionic_adev->adev);
+
+       lif->ionic_adev = NULL;
+out:
+       mutex_unlock(&lif->adev_lock);
+}

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_aux.h b/drivers/net/ethernet/pensando/ionic/ionic_aux.h
new file mode 100644 (file)
index 0000000..f5528a9
--- /dev/null
+++ b/drivers/net/ethernet/pensando/ionic/ionic_aux.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2018-2025, Advanced Micro Devices, Inc. */
+
+#ifndef _IONIC_AUX_H_
+#define _IONIC_AUX_H_
+
+int ionic_auxbus_register(struct ionic_lif *lif);
+void ionic_auxbus_unregister(struct ionic_lif *lif);
+
+#endif /* _IONIC_AUX_H_ */

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
index 136bfa3516d0027ce94fd8b54dd6e4c2e00975f1..f8752b1d2790b2b3c593716cdad9d9360b10b891 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c
@@ -9,6 +9,7 @@
 #include "ionic.h"
 #include "ionic_bus.h"
 #include "ionic_lif.h"
+#include "ionic_aux.h"
 #include "ionic_debugfs.h"
 
 /* Supported devices */
@@ -375,6 +376,8 @@ static int ionic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
                goto err_out_deregister_devlink;
        }
 
+       ionic_auxbus_register(ionic->lif);
+
        mod_timer(&ionic->watchdog_timer,
                  round_jiffies(jiffies + ionic->watchdog_period));
        ionic_queue_doorbell_check(ionic, IONIC_NAPI_DEADLINE);
@@ -416,6 +419,7 @@ static void ionic_remove(struct pci_dev *pdev)
 
                if (ionic->lif->doorbell_wa)
                        cancel_delayed_work_sync(&ionic->doorbell_check_dwork);
+               ionic_auxbus_unregister(ionic->lif);
                ionic_lif_unregister(ionic->lif);
                ionic_devlink_unregister(ionic);
                ionic_lif_deinit(ionic->lif);
@@ -445,6 +449,7 @@ static void ionic_reset_prepare(struct pci_dev *pdev)
        timer_delete_sync(&ionic->watchdog_timer);
        cancel_work_sync(&lif->deferred.work);
 
+       ionic_auxbus_unregister(ionic->lif);
        mutex_lock(&lif->queue_lock);
        ionic_stop_queues_reconfig(lif);
        ionic_txrx_free(lif);

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
index 48cb5d30b5f6f60c938eac6029e95b63561895b7..8ed5d2e5fde494ac96fe805d331279c2e09eafd6 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
@@ -19,6 +19,7 @@
 #include "ionic_bus.h"
 #include "ionic_dev.h"
 #include "ionic_lif.h"
+#include "ionic_aux.h"
 #include "ionic_txrx.h"
 #include "ionic_ethtool.h"
 #include "ionic_debugfs.h"
@@ -3293,6 +3294,7 @@ int ionic_lif_alloc(struct ionic *ionic)
 
        mutex_init(&lif->queue_lock);
        mutex_init(&lif->config_lock);
+       mutex_init(&lif->adev_lock);
 
        spin_lock_init(&lif->adminq_lock);
 
@@ -3349,6 +3351,7 @@ err_out_free_lif_info:
        lif->info = NULL;
        lif->info_pa = 0;
 err_out_free_mutex:
+       mutex_destroy(&lif->adev_lock);
        mutex_destroy(&lif->config_lock);
        mutex_destroy(&lif->queue_lock);
 err_out_free_netdev:
@@ -3384,6 +3387,7 @@ static void ionic_lif_handle_fw_down(struct ionic_lif *lif)
 
        netif_device_detach(lif->netdev);
 
+       ionic_auxbus_unregister(ionic->lif);
        mutex_lock(&lif->queue_lock);
        if (test_bit(IONIC_LIF_F_UP, lif->state)) {
                dev_info(ionic->dev, "Surprise FW stop, stopping queues\n");
@@ -3446,6 +3450,8 @@ int ionic_restart_lif(struct ionic_lif *lif)
        netif_device_attach(lif->netdev);
        ionic_queue_doorbell_check(ionic, IONIC_NAPI_DEADLINE);
 
+       ionic_auxbus_register(ionic->lif);
+
        return 0;
 
 err_txrx_free:
@@ -3528,6 +3534,7 @@ void ionic_lif_free(struct ionic_lif *lif)
 
        mutex_destroy(&lif->config_lock);
        mutex_destroy(&lif->queue_lock);
+       mutex_destroy(&lif->adev_lock);
 
        /* free netdev & lif */
        ionic_debugfs_del_lif(lif);

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.h b/drivers/net/ethernet/pensando/ionic/ionic_lif.h
index e01756fb7fdded9407c52712cfb1febc0e85da62..43bdd0fb87336eb7fb26fea9f4d02317dfe9241e 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.h
@@ -10,6 +10,7 @@
 #include <linux/dim.h>
 #include <linux/pci.h>
 #include "ionic_rx_filter.h"
+#include "ionic_api.h"
 
 #define IONIC_ADMINQ_LENGTH    16      /* must be a power of two */
 #define IONIC_NOTIFYQ_LENGTH   64      /* must be a power of two */
@@ -225,6 +226,8 @@ struct ionic_lif {
        dma_addr_t info_pa;
        u32 info_sz;
        struct ionic_qtype_info qtype_info[IONIC_QTYPE_MAX];
+       struct ionic_aux_dev *ionic_adev;
+       struct mutex adev_lock; /* lock for aux_dev actions */
 
        u8 rss_hash_key[IONIC_RSS_HASH_KEY_SIZE];
        u8 *rss_ind_tbl;