On Sun, 23 Jan 2022 16:31:19 -0800
Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> 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>
Guess we should add this to the todo list for Qemu emulation.
I wonder a bit if it is something that should really be done at the
PCI device level. Maybe a question for Bjorn.
If not, then this is fine as far as I am concerned.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> 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;
>
