Per the CXL specification (8.1.12.2 Memory Device PCIe Capabilities and
Extended Capabilities) the Device Serial Number capability is mandatory.
Emit it for user tooling to identify devices.
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-cxl | 9 +++++++++
drivers/cxl/core/memdev.c | 11 +++++++++++
drivers/cxl/cxlmem.h | 2 ++
drivers/cxl/pci.c | 1 +
tools/testing/cxl/test/mem.c | 1 +
5 files changed, 24 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
index 6d8cbf3355b5..87c0e5e65322 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -25,6 +25,15 @@ Description:
identically named field in the Identify Memory Device Output
Payload in the CXL-2.0 specification.
+What: /sys/bus/cxl/devices/memX/serial
+Date: January, 2022
+KernelVersion: v5.18
+Contact: linux-cxl@xxxxxxxxxxxxxxx
+Description:
+ (RO) 64-bit serial number per the PCIe Device Serial Number
+ capability. Mandatory for CXL devices, see CXL 2.0 8.1.12.2
+ Memory Device PCIe Capabilities and Extended Capabilities.
+
What: /sys/bus/cxl/devices/*/devtype
Date: June, 2021
KernelVersion: v5.14
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index 61029cb7ac62..1e574b052583 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -89,7 +89,18 @@ static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr,
static struct device_attribute dev_attr_pmem_size =
__ATTR(size, 0444, pmem_size_show, NULL);
+static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
+ struct cxl_dev_state *cxlds = cxlmd->cxlds;
+
+ return sysfs_emit(buf, "%#llx\n", cxlds->serial);
+}
+static DEVICE_ATTR_RO(serial);
+
static struct attribute *cxl_memdev_attributes[] = {
+ &dev_attr_serial.attr,
&dev_attr_firmware_version.attr,
&dev_attr_payload_max.attr,
&dev_attr_label_storage_size.attr,
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index e70838e5dc17..0ba0cf8dcdbc 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -131,6 +131,7 @@ struct cxl_endpoint_dvsec_info {
* @next_persistent_bytes: persistent capacity change pending device reset
* @component_reg_phys: register base of component registers
* @info: Cached DVSEC information about the device.
+ * @serial: PCIe Device Serial Number
* @mbox_send: @dev specific transport for transmitting mailbox commands
* @wait_media_ready: @dev specific method to await media ready
*
@@ -164,6 +165,7 @@ struct cxl_dev_state {
resource_size_t component_reg_phys;
struct cxl_endpoint_dvsec_info info;
+ u64 serial;
int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd);
int (*wait_media_ready)(struct cxl_dev_state *cxlds);
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 513cb0e2a70a..9252e1f4b18c 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -557,6 +557,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
if (IS_ERR(cxlds))
return PTR_ERR(cxlds);
+ cxlds->serial = pci_get_dsn(pdev);
cxlds->cxl_dvsec = pci_find_dvsec_capability(
pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC);
if (!cxlds->cxl_dvsec) {
diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
index 3af3f94de0c3..36ef337c775c 100644
--- a/tools/testing/cxl/test/mem.c
+++ b/tools/testing/cxl/test/mem.c
@@ -268,6 +268,7 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
if (IS_ERR(cxlds))
return PTR_ERR(cxlds);
+ cxlds->serial = pdev->id;
cxlds->mbox_send = cxl_mock_mbox_send;
cxlds->wait_media_ready = cxl_mock_wait_media_ready;
cxlds->payload_size = SZ_4K;
