[Patch v5 01/12] net: mana: Add support for auxiliary device

[longli@linuxonhyperv.com]

From: Long Li <longli@microsoft.com>

In preparation for supporting MANA RDMA driver, add support for auxiliary
device in the Ethernet driver. The RDMA device is modeled as an auxiliary
device to the Ethernet device.

Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Long Li <longli@microsoft.com>
---
Change log:
v3: define mana_adev_idx_alloc and mana_adev_idx_free as static

 drivers/net/ethernet/microsoft/mana/gdma.h    |  2 +
 .../ethernet/microsoft/mana/mana_auxiliary.h  | 10 +++
 drivers/net/ethernet/microsoft/mana/mana_en.c | 84 ++++++++++++++++++-
 3 files changed, 95 insertions(+), 1 deletion(-)
 create mode 100644 drivers/net/ethernet/microsoft/mana/mana_auxiliary.h

diff --git a/drivers/net/ethernet/microsoft/mana/gdma.h b/drivers/net/ethernet/microsoft/mana/gdma.h
index 41ecd156e95f..d815d323be87 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma.h
+++ b/drivers/net/ethernet/microsoft/mana/gdma.h
@@ -204,6 +204,8 @@ struct gdma_dev {
 
 	/* GDMA driver specific pointer */
 	void *driver_data;
+
+	struct auxiliary_device *adev;
 };
 
 #define MINIMUM_SUPPORTED_PAGE_SIZE PAGE_SIZE
diff --git a/drivers/net/ethernet/microsoft/mana/mana_auxiliary.h b/drivers/net/ethernet/microsoft/mana/mana_auxiliary.h
new file mode 100644
index 000000000000..373d59756846
--- /dev/null
+++ b/drivers/net/ethernet/microsoft/mana/mana_auxiliary.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2022, Microsoft Corporation. */
+
+#include "mana.h"
+#include <linux/auxiliary_bus.h>
+
+struct mana_adev {
+	struct auxiliary_device adev;
+	struct gdma_dev *mdev;
+};
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index b7d3ba1b4d17..bfe244aa0eca 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -12,6 +12,19 @@
 #include <net/ip6_checksum.h>
 
 #include "mana.h"
+#include "mana_auxiliary.h"
+
+static DEFINE_IDA(mana_adev_ida);
+
+static int mana_adev_idx_alloc(void)
+{
+	return ida_alloc(&mana_adev_ida, GFP_KERNEL);
+}
+
+static void mana_adev_idx_free(int idx)
+{
+	ida_free(&mana_adev_ida, idx);
+}
 
 /* Microsoft Azure Network Adapter (MANA) functions */
 
@@ -1960,6 +1973,70 @@ static int mana_probe_port(struct mana_context *ac, int port_idx,
 	return err;
 }
 
+static void adev_release(struct device *dev)
+{
+	struct mana_adev *madev = container_of(dev, struct mana_adev, adev.dev);
+
+	kfree(madev);
+}
+
+static void remove_adev(struct gdma_dev *gd)
+{
+	struct auxiliary_device *adev = gd->adev;
+	int id = adev->id;
+
+	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
+
+	mana_adev_idx_free(id);
+	gd->adev = NULL;
+}
+
+static int add_adev(struct gdma_dev *gd)
+{
+	struct auxiliary_device *adev;
+	struct mana_adev *madev;
+	int ret;
+
+	madev = kzalloc(sizeof(*madev), GFP_KERNEL);
+	if (!madev)
+		return -ENOMEM;
+
+	adev = &madev->adev;
+	adev->id = mana_adev_idx_alloc();
+	if (adev->id < 0) {
+		ret = adev->id;
+		goto idx_fail;
+	}
+
+	adev->name = "rdma";
+	adev->dev.parent = gd->gdma_context->dev;
+	adev->dev.release = adev_release;
+	madev->mdev = gd;
+
+	ret = auxiliary_device_init(adev);
+	if (ret)
+		goto init_fail;
+
+	ret = auxiliary_device_add(adev);
+	if (ret)
+		goto add_fail;
+
+	gd->adev = adev;
+	return 0;
+
+add_fail:
+	auxiliary_device_uninit(adev);
+
+init_fail:
+	mana_adev_idx_free(adev->id);
+
+idx_fail:
+	kfree(madev);
+
+	return ret;
+}
+
 int mana_probe(struct gdma_dev *gd, bool resuming)
 {
 	struct gdma_context *gc = gd->gdma_context;
@@ -2027,6 +2104,8 @@ int mana_probe(struct gdma_dev *gd, bool resuming)
 				break;
 		}
 	}
+
+	err = add_adev(gd);
 out:
 	if (err)
 		mana_remove(gd, false);
@@ -2043,6 +2122,10 @@ void mana_remove(struct gdma_dev *gd, bool suspending)
 	int err;
 	int i;
 
+	/* adev currently doesn't support suspending, always remove it */
+	if (gd->adev)
+		remove_adev(gd);
+
 	for (i = 0; i < ac->num_ports; i++) {
 		ndev = ac->ports[i];
 		if (!ndev) {
@@ -2075,7 +2158,6 @@ void mana_remove(struct gdma_dev *gd, bool suspending)
 	}
 
 	mana_destroy_eq(ac);
-
 out:
 	mana_gd_deregister_device(gd);
 
-- 
2.17.1