+static ssize_t cmb_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
+
+ return sysfs_emit(buf, "cmbloc : x%08x\ncmbsz : x%08x\n",
+ ndev->cmbloc, ndev->cmbsz);
+}
+static DEVICE_ATTR_RO(cmb);
+
+static ssize_t cmbloc_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
+
+ return sysfs_emit(buf, "%u\n", ndev->cmbloc);
+}
+static DEVICE_ATTR_RO(cmbloc);
+
+static ssize_t cmbsz_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
+
+ return sysfs_emit(buf, "%u\n", ndev->cmbsz);
+}
+static DEVICE_ATTR_RO(cmbsz);
+
+static ssize_t hmb_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
+
+ return sysfs_emit(buf, "%d\n", ndev->hmb);
+}
+
+static ssize_t hmb_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct nvme_dev *ndev = to_nvme_dev(dev_get_drvdata(dev));
+ bool new;
+ int ret;
+
+ if (strtobool(buf, &new) < 0)
+ return -EINVAL;
+
+ if (new == ndev->hmb)
+ return count;
+
+ if (new) {
+ ret = nvme_setup_host_mem(ndev);
+ } else {
+ ret = nvme_set_host_mem(ndev, 0);
+ if (!ret)
+ nvme_free_host_mem(ndev);
+ }
+
+ if (ret < 0)
+ return ret;
+
+ return count;
+}
+static DEVICE_ATTR_RW(hmb);
+
+static umode_t nvme_pci_attrs_are_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct nvme_ctrl *ctrl =
+ dev_get_drvdata(container_of(kobj, struct device, kobj));
+ struct nvme_dev *dev = to_nvme_dev(ctrl);
+
+ if (a == &dev_attr_cmb.attr ||
+ a == &dev_attr_cmbloc.attr ||
+ a == &dev_attr_cmbsz.attr) {
+ if (!dev->cmbsz)
+ return 0;
+ }
+ if (a == &dev_attr_hmb.attr && !ctrl->hmpre)
+ return 0;
+
+ return a->mode;
+}
+
+static struct attribute *nvme_pci_attrs[] = {
+ &dev_attr_cmb.attr,
+ &dev_attr_cmbloc.attr,
+ &dev_attr_cmbsz.attr,
+ &dev_attr_hmb.attr,
+ NULL,
+};
+
+static const struct attribute_group nvme_pci_attr_group = {
+ .attrs = nvme_pci_attrs,
+ .is_visible = nvme_pci_attrs_are_visible,
+};
+