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(vdev: vpmem->vdev,
22 c: virtio_pmem_host_ack, n: "flush_queue");
23 if (IS_ERR(ptr: vpmem->req_vq))
24 return PTR_ERR(ptr: vpmem->req_vq);
25
26 spin_lock_init(&vpmem->pmem_lock);
27 INIT_LIST_HEAD(list: &vpmem->req_list);
28
29 return 0;
30};
31
32static int virtio_pmem_validate(struct virtio_device *vdev)
33{
34 struct virtio_shm_region shm_reg;
35
36 if (virtio_has_feature(vdev, VIRTIO_PMEM_F_SHMEM_REGION) &&
37 !virtio_get_shm_region(vdev, region: &shm_reg, id: (u8)VIRTIO_PMEM_SHMEM_REGION_ID)
38 ) {
39 dev_notice(&vdev->dev, "failed to get shared memory region %d\n",
40 VIRTIO_PMEM_SHMEM_REGION_ID);
41 __virtio_clear_bit(vdev, VIRTIO_PMEM_F_SHMEM_REGION);
42 }
43 return 0;
44}
45
46static int virtio_pmem_probe(struct virtio_device *vdev)
47{
48 struct nd_region_desc ndr_desc = {};
49 struct nd_region *nd_region;
50 struct virtio_pmem *vpmem;
51 struct resource res;
52 struct virtio_shm_region shm_reg;
53 int err = 0;
54
55 if (!vdev->config->get) {
56 dev_err(&vdev->dev, "%s failure: config access disabled\n",
57 __func__);
58 return -EINVAL;
59 }
60
61 vpmem = devm_kzalloc(dev: &vdev->dev, size: sizeof(*vpmem), GFP_KERNEL);
62 if (!vpmem) {
63 err = -ENOMEM;
64 goto out_err;
65 }
66
67 vpmem->vdev = vdev;
68 vdev->priv = vpmem;
69 err = init_vq(vpmem);
70 if (err) {
71 dev_err(&vdev->dev, "failed to initialize virtio pmem vq's\n");
72 goto out_err;
73 }
74
75 if (virtio_has_feature(vdev, VIRTIO_PMEM_F_SHMEM_REGION)) {
76 virtio_get_shm_region(vdev, region: &shm_reg, id: (u8)VIRTIO_PMEM_SHMEM_REGION_ID);
77 vpmem->start = shm_reg.addr;
78 vpmem->size = shm_reg.len;
79 } else {
80 virtio_cread_le(vpmem->vdev, struct virtio_pmem_config,
81 start, &vpmem->start);
82 virtio_cread_le(vpmem->vdev, struct virtio_pmem_config,
83 size, &vpmem->size);
84 }
85
86 res.start = vpmem->start;
87 res.end = vpmem->start + vpmem->size - 1;
88 vpmem->nd_desc.provider_name = "virtio-pmem";
89 vpmem->nd_desc.module = THIS_MODULE;
90
91 vpmem->nvdimm_bus = nvdimm_bus_register(parent: &vdev->dev,
92 nfit_desc: &vpmem->nd_desc);
93 if (!vpmem->nvdimm_bus) {
94 dev_err(&vdev->dev, "failed to register device with nvdimm_bus\n");
95 err = -ENXIO;
96 goto out_vq;
97 }
98
99 dev_set_drvdata(dev: &vdev->dev, data: vpmem->nvdimm_bus);
100
101 ndr_desc.res = &res;
102
103 ndr_desc.numa_node = memory_add_physaddr_to_nid(start: res.start);
104 ndr_desc.target_node = phys_to_target_node(start: res.start);
105 if (ndr_desc.target_node == NUMA_NO_NODE) {
106 ndr_desc.target_node = ndr_desc.numa_node;
107 dev_dbg(&vdev->dev, "changing target node from %d to %d",
108 NUMA_NO_NODE, ndr_desc.target_node);
109 }
110
111 ndr_desc.flush = async_pmem_flush;
112 ndr_desc.provider_data = vdev;
113 set_bit(nr: ND_REGION_PAGEMAP, addr: &ndr_desc.flags);
114 set_bit(nr: ND_REGION_ASYNC, addr: &ndr_desc.flags);
115 /*
116 * The NVDIMM region could be available before the
117 * virtio_device_ready() that is called by
118 * virtio_dev_probe(), so we set device ready here.
119 */
120 virtio_device_ready(dev: vdev);
121 nd_region = nvdimm_pmem_region_create(nvdimm_bus: vpmem->nvdimm_bus, ndr_desc: &ndr_desc);
122 if (!nd_region) {
123 dev_err(&vdev->dev, "failed to create nvdimm region\n");
124 err = -ENXIO;
125 goto out_nd;
126 }
127 return 0;
128out_nd:
129 virtio_reset_device(dev: vdev);
130 nvdimm_bus_unregister(nvdimm_bus: vpmem->nvdimm_bus);
131out_vq:
132 vdev->config->del_vqs(vdev);
133out_err:
134 return err;
135}
136
137static void virtio_pmem_remove(struct virtio_device *vdev)
138{
139 struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(dev: &vdev->dev);
140
141 nvdimm_bus_unregister(nvdimm_bus);
142 vdev->config->del_vqs(vdev);
143 virtio_reset_device(dev: vdev);
144}
145
146static unsigned int features[] = {
147 VIRTIO_PMEM_F_SHMEM_REGION,
148};
149
150static struct virtio_driver virtio_pmem_driver = {
151 .feature_table = features,
152 .feature_table_size = ARRAY_SIZE(features),
153 .driver.name = KBUILD_MODNAME,
154 .driver.owner = THIS_MODULE,
155 .id_table = id_table,
156 .validate = virtio_pmem_validate,
157 .probe = virtio_pmem_probe,
158 .remove = virtio_pmem_remove,
159};
160
161module_virtio_driver(virtio_pmem_driver);
162MODULE_DEVICE_TABLE(virtio, id_table);
163MODULE_DESCRIPTION("Virtio pmem driver");
164MODULE_LICENSE("GPL");
165

source code of linux/drivers/nvdimm/virtio_pmem.c