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 12 static struct virtio_device_id id_table[] = { 13 { VIRTIO_ID_PMEM, VIRTIO_DEV_ANY_ID }, 14 { 0 }, 15 }; 16 17 /* Initialize virt queue */ 18 static 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 32 static 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, &shm_reg, (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 46 static 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(&vdev->dev, sizeof(*vpmem), GFP_KERNEL); 62 if (!vpmem) { 63 err = -ENOMEM; 64 goto out_err; 65 } 66 67 mutex_init(&vpmem->flush_lock); 68 vpmem->vdev = vdev; 69 vdev->priv = vpmem; 70 err = init_vq(vpmem); 71 if (err) { 72 dev_err(&vdev->dev, "failed to initialize virtio pmem vq's\n"); 73 goto out_err; 74 } 75 76 if (virtio_has_feature(vdev, VIRTIO_PMEM_F_SHMEM_REGION)) { 77 virtio_get_shm_region(vdev, &shm_reg, (u8)VIRTIO_PMEM_SHMEM_REGION_ID); 78 vpmem->start = shm_reg.addr; 79 vpmem->size = shm_reg.len; 80 } else { 81 virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, 82 start, &vpmem->start); 83 virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, 84 size, &vpmem->size); 85 } 86 87 res.start = vpmem->start; 88 res.end = vpmem->start + vpmem->size - 1; 89 vpmem->nd_desc.provider_name = "virtio-pmem"; 90 vpmem->nd_desc.module = THIS_MODULE; 91 92 vpmem->nvdimm_bus = nvdimm_bus_register(&vdev->dev, 93 &vpmem->nd_desc); 94 if (!vpmem->nvdimm_bus) { 95 dev_err(&vdev->dev, "failed to register device with nvdimm_bus\n"); 96 err = -ENXIO; 97 goto out_vq; 98 } 99 100 dev_set_drvdata(&vdev->dev, vpmem->nvdimm_bus); 101 102 ndr_desc.res = &res; 103 104 ndr_desc.numa_node = memory_add_physaddr_to_nid(res.start); 105 ndr_desc.target_node = phys_to_target_node(res.start); 106 if (ndr_desc.target_node == NUMA_NO_NODE) { 107 ndr_desc.target_node = ndr_desc.numa_node; 108 dev_dbg(&vdev->dev, "changing target node from %d to %d", 109 NUMA_NO_NODE, ndr_desc.target_node); 110 } 111 112 ndr_desc.flush = async_pmem_flush; 113 ndr_desc.provider_data = vdev; 114 set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags); 115 set_bit(ND_REGION_ASYNC, &ndr_desc.flags); 116 /* 117 * The NVDIMM region could be available before the 118 * virtio_device_ready() that is called by 119 * virtio_dev_probe(), so we set device ready here. 120 */ 121 virtio_device_ready(vdev); 122 nd_region = nvdimm_pmem_region_create(vpmem->nvdimm_bus, &ndr_desc); 123 if (!nd_region) { 124 dev_err(&vdev->dev, "failed to create nvdimm region\n"); 125 err = -ENXIO; 126 goto out_nd; 127 } 128 return 0; 129 out_nd: 130 virtio_reset_device(vdev); 131 nvdimm_bus_unregister(vpmem->nvdimm_bus); 132 out_vq: 133 vdev->config->del_vqs(vdev); 134 out_err: 135 return err; 136 } 137 138 static void virtio_pmem_remove(struct virtio_device *vdev) 139 { 140 struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(&vdev->dev); 141 142 nvdimm_bus_unregister(nvdimm_bus); 143 vdev->config->del_vqs(vdev); 144 virtio_reset_device(vdev); 145 } 146 147 static int virtio_pmem_freeze(struct virtio_device *vdev) 148 { 149 vdev->config->del_vqs(vdev); 150 virtio_reset_device(vdev); 151 152 return 0; 153 } 154 155 static int virtio_pmem_restore(struct virtio_device *vdev) 156 { 157 int ret; 158 159 ret = init_vq(vdev->priv); 160 if (ret) { 161 dev_err(&vdev->dev, "failed to initialize virtio pmem's vq\n"); 162 return ret; 163 } 164 virtio_device_ready(vdev); 165 166 return 0; 167 } 168 169 static unsigned int features[] = { 170 VIRTIO_PMEM_F_SHMEM_REGION, 171 }; 172 173 static struct virtio_driver virtio_pmem_driver = { 174 .feature_table = features, 175 .feature_table_size = ARRAY_SIZE(features), 176 .driver.name = KBUILD_MODNAME, 177 .id_table = id_table, 178 .validate = virtio_pmem_validate, 179 .probe = virtio_pmem_probe, 180 .remove = virtio_pmem_remove, 181 .freeze = virtio_pmem_freeze, 182 .restore = virtio_pmem_restore, 183 }; 184 185 module_virtio_driver(virtio_pmem_driver); 186 MODULE_DEVICE_TABLE(virtio, id_table); 187 MODULE_DESCRIPTION("Virtio pmem driver"); 188 MODULE_LICENSE("GPL"); 189