drivers/nvdimm/virtio_pmem.c

   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_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;
  94 out_nd:
  95         nvdimm_bus_unregister(vpmem->nvdimm_bus);
  96 out_vq:
  97         vdev->config->del_vqs(vdev);
  98 out_err:
  99         return err;
 100 }
 101
 102 static 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         virtio_reset_device(vdev);
 109 }
 110
 111 static 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
 119 module_virtio_driver(virtio_pmem_driver);
 120 MODULE_DEVICE_TABLE(virtio, id_table);
 121 MODULE_DESCRIPTION("Virtio pmem driver");
 122 MODULE_LICENSE("GPL");