[RFC 2/2] vhost: IFC VF vdpa layer

[Zhu Lingshan]

This commit introduced IFC VF operations for vdpa, which complys to
vhost_mdev interfaces, handles IFC VF initialization,
configuration and removal.

Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
---
 drivers/vhost/ifcvf/ifcvf_main.c | 541 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 541 insertions(+)
 create mode 100644 drivers/vhost/ifcvf/ifcvf_main.c

diff --git a/drivers/vhost/ifcvf/ifcvf_main.c b/drivers/vhost/ifcvf/ifcvf_main.c
new file mode 100644
index 000000000000..c48a29969a85
--- /dev/null
+++ b/drivers/vhost/ifcvf/ifcvf_main.c
@@ -0,0 +1,541 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 Intel Corporation.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mdev.h>
+#include <linux/pci.h>
+#include <linux/sysfs.h>
+
+#include "ifcvf_base.h"
+
+#define VERSION_STRING	"0.1"
+#define DRIVER_AUTHOR	"Intel Corporation"
+#define IFCVF_DRIVER_NAME	"ifcvf"
+
+static irqreturn_t ifcvf_intr_handler(int irq, void *arg)
+{
+	struct vring_info *vring = arg;
+
+	if (vring->cb.callback)
+		return vring->cb.callback(vring->cb.private);
+
+	return IRQ_HANDLED;
+}
+
+static u64 ifcvf_mdev_get_features(struct mdev_device *mdev)
+{
+	return IFC_SUPPORTED_FEATURES;
+}
+
+static int ifcvf_mdev_set_features(struct mdev_device *mdev, u64 features)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	vf->req_features = features;
+
+	return 0;
+}
+
+static u64 ifcvf_mdev_get_vq_state(struct mdev_device *mdev, u16 qid)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	return vf->vring[qid].last_avail_idx;
+}
+
+static int ifcvf_mdev_set_vq_state(struct mdev_device *mdev, u16 qid, u64 num)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	vf->vring[qid].last_used_idx = num;
+	vf->vring[qid].last_avail_idx = num;
+
+	return 0;
+}
+
+static int ifcvf_mdev_set_vq_address(struct mdev_device *mdev, u16 idx,
+				     u64 desc_area, u64 driver_area,
+				     u64 device_area)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	vf->vring[idx].desc = desc_area;
+	vf->vring[idx].avail = driver_area;
+	vf->vring[idx].used = device_area;
+
+	return 0;
+}
+
+static void ifcvf_mdev_set_vq_num(struct mdev_device *mdev, u16 qid, u32 num)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	vf->vring[qid].size = num;
+}
+
+static void ifcvf_mdev_set_vq_ready(struct mdev_device *mdev,
+				u16 qid, bool ready)
+{
+
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	vf->vring[qid].ready = ready;
+}
+
+static bool ifcvf_mdev_get_vq_ready(struct mdev_device *mdev, u16 qid)
+{
+
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	return vf->vring[qid].ready;
+}
+
+static void ifcvf_mdev_set_vq_cb(struct mdev_device *mdev, u16 idx,
+				 struct virtio_mdev_callback *cb)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	vf->vring[idx].cb = *cb;
+}
+
+static void ifcvf_mdev_kick_vq(struct mdev_device *mdev, u16 idx)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	ifcvf_notify_queue(vf, idx);
+}
+
+static u8 ifcvf_mdev_get_status(struct mdev_device *mdev)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	return vf->status;
+}
+
+static u32 ifcvf_mdev_get_generation(struct mdev_device *mdev)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	return vf->generation;
+}
+
+static int ifcvf_mdev_get_version(struct mdev_device *mdev)
+{
+	return VIRTIO_MDEV_VERSION;
+}
+
+static u32 ifcvf_mdev_get_device_id(struct mdev_device *mdev)
+{
+	return IFCVF_DEVICE_ID;
+}
+
+static u32 ifcvf_mdev_get_vendor_id(struct mdev_device *mdev)
+{
+	return IFCVF_VENDOR_ID;
+}
+
+static u16 ifcvf_mdev_get_vq_align(struct mdev_device *mdev)
+{
+	return IFCVF_QUEUE_ALIGNMENT;
+}
+
+static int ifcvf_start_datapath(void *private)
+{
+	int i, ret;
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(private);
+
+	for (i = 0; i < (IFCVF_MAX_QUEUE_PAIRS * 2); i++) {
+		if (!vf->vring[i].ready)
+			break;
+
+		if (!vf->vring[i].size)
+			break;
+
+		if (!vf->vring[i].desc || !vf->vring[i].avail ||
+			!vf->vring[i].used)
+			break;
+	}
+	vf->nr_vring = i;
+
+	ret = ifcvf_start_hw(vf);
+	return ret;
+}
+
+static int ifcvf_stop_datapath(void *private)
+{
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(private);
+	int i;
+
+	for (i = 0; i < IFCVF_MAX_QUEUES; i++)
+		vf->vring[i].cb.callback = NULL;
+
+	ifcvf_stop_hw(vf);
+
+	return 0;
+}
+
+static void ifcvf_reset_vring(struct ifcvf_adapter *adapter)
+{
+	int i;
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+		vf->vring[i].last_used_idx = 0;
+		vf->vring[i].last_avail_idx = 0;
+		vf->vring[i].desc = 0;
+		vf->vring[i].avail = 0;
+		vf->vring[i].used = 0;
+		vf->vring[i].ready = 0;
+		vf->vring->cb.callback = NULL;
+		vf->vring->cb.private = NULL;
+	}
+}
+
+static void ifcvf_mdev_set_status(struct mdev_device *mdev, u8 status)
+{
+	struct ifcvf_adapter *adapter = mdev_get_drvdata(mdev);
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+
+	vf->status = status;
+
+	if (status == 0) {
+		ifcvf_stop_datapath(adapter);
+		ifcvf_reset_vring(adapter);
+		return;
+	}
+
+	if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
+		ifcvf_start_datapath(adapter);
+		return;
+	}
+}
+
+static u16 ifcvf_mdev_get_queue_max(struct mdev_device *mdev)
+{
+	return IFCVF_MAX_QUEUES;
+}
+
+static struct virtio_mdev_device_ops ifc_mdev_ops = {
+	.get_features  = ifcvf_mdev_get_features,
+	.set_features  = ifcvf_mdev_set_features,
+	.get_status    = ifcvf_mdev_get_status,
+	.set_status    = ifcvf_mdev_set_status,
+	.get_queue_max = ifcvf_mdev_get_queue_max,
+	.get_vq_state   = ifcvf_mdev_get_vq_state,
+	.set_vq_state   = ifcvf_mdev_set_vq_state,
+	.set_vq_cb      = ifcvf_mdev_set_vq_cb,
+	.set_vq_ready   = ifcvf_mdev_set_vq_ready,
+	.get_vq_ready	= ifcvf_mdev_get_vq_ready,
+	.set_vq_num     = ifcvf_mdev_set_vq_num,
+	.set_vq_address = ifcvf_mdev_set_vq_address,
+	.kick_vq        = ifcvf_mdev_kick_vq,
+	.get_generation	= ifcvf_mdev_get_generation,
+	.get_version	= ifcvf_mdev_get_version,
+	.get_device_id	= ifcvf_mdev_get_device_id,
+	.get_vendor_id	= ifcvf_mdev_get_vendor_id,
+	.get_vq_align	= ifcvf_mdev_get_vq_align,
+};
+
+static int ifcvf_init_msix(struct ifcvf_adapter *adapter)
+{
+	int vector, i, ret, irq;
+	struct pci_dev *pdev = to_pci_dev(adapter->dev);
+	struct ifcvf_hw *vf = &adapter->vf;
+
+	ret = pci_alloc_irq_vectors(pdev, IFCVF_MAX_INTR,
+			IFCVF_MAX_INTR, PCI_IRQ_MSIX);
+	if (ret < 0) {
+		IFC_ERR(adapter->dev, "Failed to alloc irq vectors.\n");
+		return ret;
+	}
+
+	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+		vector = i + IFCVF_MSI_QUEUE_OFF;
+		irq = pci_irq_vector(pdev, vector);
+		ret = request_irq(irq, ifcvf_intr_handler, 0,
+				pci_name(pdev), &vf->vring[i]);
+		if (ret) {
+			IFC_ERR(adapter->dev,
+				"Failed to request irq for vq %d.\n", i);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void ifcvf_destroy_adapter(struct ifcvf_adapter *adapter)
+{
+	int i, vector, irq;
+	struct ifcvf_hw *vf = IFC_PRIVATE_TO_VF(adapter);
+	struct pci_dev *pdev = to_pci_dev(adapter->dev);
+
+	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+		vector = i + IFCVF_MSI_QUEUE_OFF;
+		irq = pci_irq_vector(pdev, vector);
+		free_irq(irq, &vf->vring[i]);
+	}
+}
+
+static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+	const char *name = "vhost accelerator (virtio ring compatible)";
+
+	return sprintf(buf, "%s\n", name);
+}
+MDEV_TYPE_ATTR_RO(name);
+
+static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
+			       char *buf)
+{
+	return sprintf(buf, "%s\n", VIRTIO_MDEV_DEVICE_API_STRING);
+}
+MDEV_TYPE_ATTR_RO(device_api);
+
+static ssize_t available_instances_show(struct kobject *kobj,
+					struct device *dev, char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ifcvf_adapter *adapter = pci_get_drvdata(pdev);
+
+	return sprintf(buf, "%d\n", adapter->mdev_count);
+}
+
+MDEV_TYPE_ATTR_RO(available_instances);
+
+static ssize_t type_show(struct kobject *kobj,
+			struct device *dev, char *buf)
+{
+	return sprintf(buf, "%s\n", "net");
+}
+
+MDEV_TYPE_ATTR_RO(type);
+
+
+static struct attribute *mdev_types_attrs[] = {
+	&mdev_type_attr_name.attr,
+	&mdev_type_attr_device_api.attr,
+	&mdev_type_attr_available_instances.attr,
+	&mdev_type_attr_type.attr,
+	NULL,
+};
+
+static struct attribute_group mdev_type_group = {
+	.name  = "vdpa_virtio",
+	.attrs = mdev_types_attrs,
+};
+
+static struct attribute_group *mdev_type_groups[] = {
+	&mdev_type_group,
+	NULL,
+};
+
+const struct attribute_group *mdev_dev_groups[] = {
+	NULL,
+};
+
+static int ifcvf_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
+{
+	struct device *dev = mdev_parent_dev(mdev);
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ifcvf_adapter *adapter = pci_get_drvdata(pdev);
+	int ret = 0;
+
+	mutex_lock(&adapter->mdev_lock);
+
+	if (adapter->mdev_count < 1) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	mdev_set_class_id(mdev, MDEV_ID_VHOST);
+	mdev_set_dev_ops(mdev, &ifc_mdev_ops);
+
+	mdev_set_drvdata(mdev, adapter);
+	mdev_set_iommu_device(mdev_dev(mdev), dev);
+
+	INIT_LIST_HEAD(&adapter->dma_maps);
+	adapter->mdev_count--;
+
+out:
+	mutex_unlock(&adapter->mdev_lock);
+	return ret;
+}
+
+static int ifcvf_mdev_remove(struct mdev_device *mdev)
+{
+	struct device *dev = mdev_parent_dev(mdev);
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ifcvf_adapter *adapter = pci_get_drvdata(pdev);
+
+	mutex_lock(&adapter->mdev_lock);
+	adapter->mdev_count++;
+	mutex_unlock(&adapter->mdev_lock);
+
+	return 0;
+}
+
+static struct mdev_parent_ops ifcvf_mdev_fops = {
+	.owner			= THIS_MODULE,
+	.supported_type_groups	= mdev_type_groups,
+	.mdev_attr_groups	= mdev_dev_groups,
+	.create			= ifcvf_mdev_create,
+	.remove			= ifcvf_mdev_remove,
+};
+
+static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct device *dev = &pdev->dev;
+	struct ifcvf_adapter *adapter;
+	struct ifcvf_hw *vf;
+	int ret, i;
+
+	adapter = kzalloc(sizeof(struct ifcvf_adapter), GFP_KERNEL);
+	if (adapter == NULL) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	mutex_init(&adapter->mdev_lock);
+	adapter->mdev_count = 1;
+	adapter->dev = dev;
+
+	pci_set_drvdata(pdev, adapter);
+
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		IFC_ERR(adapter->dev, "Failed to enable device.\n");
+		goto free_adapter;
+	}
+
+	ret = pci_request_regions(pdev, IFCVF_DRIVER_NAME);
+	if (ret) {
+		IFC_ERR(adapter->dev, "Failed to request MMIO region.\n");
+		goto disable_device;
+	}
+
+	pci_set_master(pdev);
+
+	ret = ifcvf_init_msix(adapter);
+	if (ret) {
+		IFC_ERR(adapter->dev, "Failed to initialize MSIX.\n");
+		goto free_msix;
+	}
+
+	vf = &adapter->vf;
+	for (i = 0; i < IFCVF_PCI_MAX_RESOURCE; i++) {
+		vf->mem_resource[i].phys_addr = pci_resource_start(pdev, i);
+		vf->mem_resource[i].len = pci_resource_len(pdev, i);
+		if (!vf->mem_resource[i].len) {
+			vf->mem_resource[i].addr = NULL;
+			continue;
+		}
+
+		vf->mem_resource[i].addr = pci_iomap_range(pdev, i, 0,
+				vf->mem_resource[i].len);
+		if (!vf->mem_resource[i].addr) {
+			IFC_ERR(adapter->dev, "Failed to map IO resource %d\n",
+				i);
+			return -1;
+		}
+	}
+
+	if (ifcvf_init_hw(vf, pdev) < 0)
+		return -1;
+
+	ret = mdev_register_device(dev, &ifcvf_mdev_fops);
+	if (ret) {
+		IFC_ERR(adapter->dev,  "Failed to register mdev device\n");
+		goto destroy_adapter;
+	}
+
+	return 0;
+
+destroy_adapter:
+	ifcvf_destroy_adapter(adapter);
+free_msix:
+	pci_free_irq_vectors(pdev);
+	pci_release_regions(pdev);
+disable_device:
+	pci_disable_device(pdev);
+free_adapter:
+	kfree(adapter);
+fail:
+	return ret;
+}
+
+static void ifcvf_remove(struct pci_dev *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ifcvf_adapter *adapter = pci_get_drvdata(pdev);
+	struct ifcvf_hw *vf;
+	int i;
+
+	mdev_unregister_device(dev);
+
+	vf = &adapter->vf;
+	for (i = 0; i < IFCVF_PCI_MAX_RESOURCE; i++) {
+		if (vf->mem_resource[i].addr) {
+			pci_iounmap(pdev, vf->mem_resource[i].addr);
+			vf->mem_resource[i].addr = NULL;
+		}
+	}
+
+	ifcvf_destroy_adapter(adapter);
+	pci_free_irq_vectors(pdev);
+
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+
+	kfree(adapter);
+}
+
+static struct pci_device_id ifcvf_pci_ids[] = {
+	{ PCI_DEVICE_SUB(IFCVF_VENDOR_ID,
+			IFCVF_DEVICE_ID,
+			IFCVF_SUBSYS_VENDOR_ID,
+			IFCVF_SUBSYS_DEVICE_ID) },
+	{ 0 },
+};
+MODULE_DEVICE_TABLE(pci, ifcvf_pci_ids);
+
+static struct pci_driver ifcvf_driver = {
+	.name     = IFCVF_DRIVER_NAME,
+	.id_table = ifcvf_pci_ids,
+	.probe    = ifcvf_probe,
+	.remove   = ifcvf_remove,
+};
+
+static int __init ifcvf_init_module(void)
+{
+	int ret;
+
+	ret = pci_register_driver(&ifcvf_driver);
+	return ret;
+}
+
+static void __exit ifcvf_exit_module(void)
+{
+	pci_unregister_driver(&ifcvf_driver);
+}
+
+module_init(ifcvf_init_module);
+module_exit(ifcvf_exit_module);
+
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(VERSION_STRING);
+MODULE_AUTHOR(DRIVER_AUTHOR);
-- 
2.16.4