[PATCH 4/8] nvme: add fabrics sysfs attributes

Christoph Hellwig
2016-06-13T14:45:24Z

From: Ming Lin <ming.l-Vzezgt5dB6uUEJcrhfAQsw@public.gmane.org>

- delete_controller: This attribute allows to delete a controller.
A driver is not obligated to support it (pci doesn't) so it is
created only if the driver supports it. The new fabrics drivers
will support it (essentialy a disconnect operation).

Usage:
echo > /sys/class/nvme/nvme0/delete_controller

- subsysnqn: This attribute shows the subsystem nqn of the configured
device. If a driver does not implement the get_subsysnqn method, the
file will not appear in sysfs.

- transport: This attribute shows the transport name. Added a "name"
field to struct nvme_ctrl_ops.

For loop,
cat /sys/class/nvme/nvme0/transport
loop

For RDMA,
cat /sys/class/nvme/nvme0/transport
rdma

For PCIe,
cat /sys/class/nvme/nvme0/transport
pcie

- address: This attributes shows the controller address. The fabrics
drivers that will implement get_address can show the address of the
connected controller.

example:
cat /sys/class/nvme/nvme0/address
traddr=192.168.2.2,trsvcid=1023

Signed-off-by: Ming Lin <ming.l-Vzezgt5dB6uUEJcrhfAQsw@public.gmane.org>
Reviewed-by: Jay Freyensee <james.p.freyensee-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
drivers/nvme/host/core.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++--
drivers/nvme/host/nvme.h | 4 +++
drivers/nvme/host/pci.c | 1 +
3 files changed, 78 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index bd04ec6..f5676c6 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1362,7 +1362,7 @@ static struct attribute *nvme_ns_attrs[] = {
NULL,
};

-static umode_t nvme_attrs_are_visible(struct kobject *kobj,
+static umode_t nvme_ns_attrs_are_visible(struct kobject *kobj,
struct attribute *a, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
@@ -1381,7 +1381,7 @@ static umode_t nvme_attrs_are_visible(struct kobject *kobj,

static const struct attribute_group nvme_ns_attr_group = {
.attrs = nvme_ns_attrs,
- .is_visible = nvme_attrs_are_visible,
+ .is_visible = nvme_ns_attrs_are_visible,
};

#define nvme_show_str_function(field) \
@@ -1407,6 +1407,49 @@ nvme_show_str_function(serial);
nvme_show_str_function(firmware_rev);
nvme_show_int_function(cntlid);

+static ssize_t nvme_sysfs_delete(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+ if (device_remove_file_self(dev, attr))
+ ctrl->ops->delete_ctrl(ctrl);
+ return count;
+}
+static DEVICE_ATTR(delete_controller, S_IWUSR, NULL, nvme_sysfs_delete);
+
+static ssize_t nvme_sysfs_show_transport(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%s\n", ctrl->ops->name);
+}
+static DEVICE_ATTR(transport, S_IRUGO, nvme_sysfs_show_transport, NULL);
+
+static ssize_t nvme_sysfs_show_subsysnqn(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%s\n",
+ ctrl->ops->get_subsysnqn(ctrl));
+}
+static DEVICE_ATTR(subsysnqn, S_IRUGO, nvme_sysfs_show_subsysnqn, NULL);
+
+static ssize_t nvme_sysfs_show_address(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+ return ctrl->ops->get_address(ctrl, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR(address, S_IRUGO, nvme_sysfs_show_address, NULL);
+
static struct attribute *nvme_dev_attrs[] = {
&dev_attr_reset_controller.attr,
&dev_attr_rescan_controller.attr,
@@ -1414,11 +1457,38 @@ static struct attribute *nvme_dev_attrs[] = {
&dev_attr_serial.attr,
&dev_attr_firmware_rev.attr,
&dev_attr_cntlid.attr,
+ &dev_attr_delete_controller.attr,
+ &dev_attr_transport.attr,
+ &dev_attr_subsysnqn.attr,
+ &dev_attr_address.attr,
NULL
};

+#define CHECK_ATTR(ctrl, a, name) \
+ if ((a) == &dev_attr_##name.attr && \
+ !(ctrl)->ops->get_##name) \
+ return 0
+
+static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+ if (a == &dev_attr_delete_controller.attr) {
+ if (!ctrl->ops->delete_ctrl)
+ return 0;
+ }
+
+ CHECK_ATTR(ctrl, a, subsysnqn);
+ CHECK_ATTR(ctrl, a, address);
+
+ return a->mode;
+}
+
static struct attribute_group nvme_dev_attrs_group = {
- .attrs = nvme_dev_attrs,
+ .attrs = nvme_dev_attrs,
+ .is_visible = nvme_dev_attrs_are_visible,
};

static const struct attribute_group *nvme_dev_attr_groups[] = {
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 68a67ac..c99acb0 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -144,6 +144,7 @@ struct nvme_ns {
};

struct nvme_ctrl_ops {
+ const char *name;
struct module *module;
int (*reg_read32)(struct nvme_ctrl *ctrl, u32 off, u32 *val);
int (*reg_write32)(struct nvme_ctrl *ctrl, u32 off, u32 val);
@@ -152,6 +153,9 @@ struct nvme_ctrl_ops {
void (*free_ctrl)(struct nvme_ctrl *ctrl);
void (*post_scan)(struct nvme_ctrl *ctrl);
void (*submit_async_event)(struct nvme_ctrl *ctrl, int aer_idx);
+ int (*delete_ctrl)(struct nvme_ctrl *ctrl);
+ const char *(*get_subsysnqn)(struct nvme_ctrl *ctrl);
+ int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size);
};

static inline bool nvme_ctrl_ready(struct nvme_ctrl *ctrl)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index db6fdee..de222ed 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1873,6 +1873,7 @@ static int nvme_pci_reset_ctrl(struct nvme_ctrl *ctrl)
}

static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
+ .name = "pcie",
.module = THIS_MODULE,
.reg_read32 = nvme_pci_reg_read32,
.reg_write32 = nvme_pci_reg_write32,