1// SPDX-License-Identifier: GPL-2.0
2/*
3 * virtio_pmem.c: Virtio pmem Driver
4 *
5 * Discovers persistent memory range information
6 * from host and registers the virtual pmem device
7 * with libnvdimm core.
8 */
9#include "virtio_pmem.h"
10#include "nd.h"
11
12static struct virtio_device_id id_table[] = {
13	{ VIRTIO_ID_PMEM, VIRTIO_DEV_ANY_ID },
14	{ 0 },
15};
16
17 /* Initialize virt queue */
18static int init_vq(struct virtio_pmem *vpmem)
19{
20	/* single vq */
21	vpmem->req_vq = virtio_find_single_vq(vpmem->vdev,
22					virtio_pmem_host_ack, "flush_queue");
23	if (IS_ERR(vpmem->req_vq))
24		return PTR_ERR(vpmem->req_vq);
25
26	spin_lock_init(&vpmem->pmem_lock);
27	INIT_LIST_HEAD(&vpmem->req_list);
28
29	return 0;
30};
31
32static int virtio_pmem_probe(struct virtio_device *vdev)
33{
34	struct nd_region_desc ndr_desc = {};
35	int nid = dev_to_node(&vdev->dev);
36	struct nd_region *nd_region;
37	struct virtio_pmem *vpmem;
38	struct resource res;
39	int err = 0;
40
41	if (!vdev->config->get) {
42		dev_err(&vdev->dev, "%s failure: config access disabled\n",
43			__func__);
44		return -EINVAL;
45	}
46
47	vpmem = devm_kzalloc(&vdev->dev, sizeof(*vpmem), GFP_KERNEL);
48	if (!vpmem) {
49		err = -ENOMEM;
50		goto out_err;
51	}
52
53	vpmem->vdev = vdev;
54	vdev->priv = vpmem;
55	err = init_vq(vpmem);
56	if (err) {
57		dev_err(&vdev->dev, "failed to initialize virtio pmem vq's\n");
58		goto out_err;
59	}
60
61	virtio_cread_le(vpmem->vdev, struct virtio_pmem_config,
62			start, &vpmem->start);
63	virtio_cread_le(vpmem->vdev, struct virtio_pmem_config,
64			size, &vpmem->size);
65
66	res.start = vpmem->start;
67	res.end   = vpmem->start + vpmem->size - 1;
68	vpmem->nd_desc.provider_name = "virtio-pmem";
69	vpmem->nd_desc.module = THIS_MODULE;
70
71	vpmem->nvdimm_bus = nvdimm_bus_register(&vdev->dev,
72						&vpmem->nd_desc);
73	if (!vpmem->nvdimm_bus) {
74		dev_err(&vdev->dev, "failed to register device with nvdimm_bus\n");
75		err = -ENXIO;
76		goto out_vq;
77	}
78
79	dev_set_drvdata(&vdev->dev, vpmem->nvdimm_bus);
80
81	ndr_desc.res = &res;
82	ndr_desc.numa_node = nid;
83	ndr_desc.flush = async_pmem_flush;
84	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
85	set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
86	nd_region = nvdimm_pmem_region_create(vpmem->nvdimm_bus, &ndr_desc);
87	if (!nd_region) {
88		dev_err(&vdev->dev, "failed to create nvdimm region\n");
89		err = -ENXIO;
90		goto out_nd;
91	}
92	nd_region->provider_data = dev_to_virtio(nd_region->dev.parent->parent);
93	return 0;
94out_nd:
95	nvdimm_bus_unregister(vpmem->nvdimm_bus);
96out_vq:
97	vdev->config->del_vqs(vdev);
98out_err:
99	return err;
100}
101
102static void virtio_pmem_remove(struct virtio_device *vdev)
103{
104	struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(&vdev->dev);
105
106	nvdimm_bus_unregister(nvdimm_bus);
107	vdev->config->del_vqs(vdev);
108	vdev->config->reset(vdev);
109}
110
111static struct virtio_driver virtio_pmem_driver = {
112	.driver.name		= KBUILD_MODNAME,
113	.driver.owner		= THIS_MODULE,
114	.id_table		= id_table,
115	.probe			= virtio_pmem_probe,
116	.remove			= virtio_pmem_remove,
117};
118
119module_virtio_driver(virtio_pmem_driver);
120MODULE_DEVICE_TABLE(virtio, id_table);
121MODULE_DESCRIPTION("Virtio pmem driver");
122MODULE_LICENSE("GPL");
123