RE: [PATCH v5 18/18] cxl: add dimm_id support for __nvdimm_create()

[Dan Williams <dan.j.williams@intel.com>]

Dave Jiang wrote:
> Set the cxlds->serial as the dimm_id to be fed to __nvdimm_create(). The
> security code uses that as the key description for the security key of the
> memory device. The nvdimm unlock code cannot find the respective key
> without the dimm_id.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/cxl/cxlmem.h         |    3 +++
>  drivers/cxl/pci.c            |    4 ++++
>  drivers/cxl/pmem.c           |    4 +++-
>  tools/testing/cxl/test/mem.c |    4 ++++
>  4 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 75baeb0bbe57..76bdec873868 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -178,6 +178,8 @@ struct cxl_endpoint_dvsec_info {
>  	struct range dvsec_range[2];
>  };
>  
> +#define CXL_DEV_ID_LEN 32
> +
>  /**
>   * struct cxl_dev_state - The driver device state
>   *
> @@ -244,6 +246,7 @@ struct cxl_dev_state {
>  
>  	resource_size_t component_reg_phys;
>  	u64 serial;
> +	u8 dev_id[CXL_DEV_ID_LEN]; /* for nvdimm, string of 'serial' */
>  
>  	struct xarray doe_mbs;
>  
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index 621a0522b554..c48fcd2a90ef 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -456,6 +456,10 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  		return PTR_ERR(cxlds);
>  
>  	cxlds->serial = pci_get_dsn(pdev);
> +	rc = snprintf(cxlds->dev_id, CXL_DEV_ID_LEN, "%llu", cxlds->serial);
> +	if (rc <= 0)
> +		return -ENXIO;
> +

Per below, move this to cxl_nvd, but also if you change the format
string to %#llx then you know you can reduce CXL_DEV_ID_LEN to 19
because a 64-bit number will never take more than 18 characters to
print.

>  	cxlds->cxl_dvsec = pci_find_dvsec_capability(
>  		pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
>  	if (!cxlds->cxl_dvsec)
> diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
> index 322f834cc27d..80556dc8d29c 100644
> --- a/drivers/cxl/pmem.c
> +++ b/drivers/cxl/pmem.c
> @@ -112,9 +112,11 @@ static int cxl_nvdimm_probe(struct device *dev)
>  	set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);
>  	set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask);
>  	set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask);
> +
>  	nvdimm = __nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd,
>  				 cxl_dimm_attribute_groups, flags,
> -				 cmd_mask, 0, NULL, NULL, cxl_security_ops, NULL);
> +				 cmd_mask, 0, NULL, cxlds->dev_id,
> +				 cxl_security_ops, NULL);

I would hang this off of cxl_nvd->dev_id, not cxlds->dev_id, since the
former is associated with the nvdimm side of a cxl_memdev.

>  	if (!nvdimm) {
>  		rc = -ENOMEM;
>  		goto out;
> diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> index 38f1cea0a353..94a3f42096c8 100644
> --- a/tools/testing/cxl/test/mem.c
> +++ b/tools/testing/cxl/test/mem.c
> @@ -593,6 +593,10 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
>  		return PTR_ERR(cxlds);
>  
>  	cxlds->serial = pdev->id;
> +	rc = snprintf(cxlds->dev_id, CXL_DEV_ID_LEN, "%llu", cxlds->serial);
> +	if (rc <= 0)
> +		return -ENXIO;
> +
>  	cxlds->mbox_send = cxl_mock_mbox_send;
>  	cxlds->payload_size = SZ_4K;
>  
> 
>