acpi, nfit: hide unknown commands from nmemX/commands

For vendor specific commands that do not have a common kernel
translation, hide them from nmemX/commands. For example, the following
results from new enabling to probe for support of the new
NVDIMM_FAMILY_INTEL DSMs specified in v1.6 of the command specification
[1]:

    # cat /sys/bus/nd/devices/nmem0/commands
    smart smart_thresh flags get_size get_data set_data effect_size
    effect_log vendor cmd_call unknown unknown unknown unknown unknown
    unknown unknown unknown

[1]: https://pmem.io/documents/NVDIMM_DSM_Interface-V1.6.pdfSigned-off-by: NDan Williams <dan.j.williams@intel.com>

drivers/acpi/nfit/core.c

@@ -1769,8 +1769,14 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 		 * userspace interface.
 		 */
 		cmd_mask = 1UL << ND_CMD_CALL;
-		if (nfit_mem->family == NVDIMM_FAMILY_INTEL)
-			cmd_mask |= nfit_mem->dsm_mask;
+		if (nfit_mem->family == NVDIMM_FAMILY_INTEL) {
+			/*
+			 * These commands have a 1:1 correspondence
+			 * between DSM payload and libnvdimm ioctl
+			 * payload format.
+			 */
+			cmd_mask |= nfit_mem->dsm_mask & NVDIMM_STANDARD_CMDMASK;
+		}
 
 		if (nfit_mem->has_lsi)
 			set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);

drivers/acpi/nfit/nfit.h

@@ -38,6 +38,12 @@
 		| ACPI_NFIT_MEM_RESTORE_FAILED | ACPI_NFIT_MEM_FLUSH_FAILED \
 		| ACPI_NFIT_MEM_NOT_ARMED | ACPI_NFIT_MEM_MAP_FAILED)
 
+#define NVDIMM_STANDARD_CMDMASK \
+(1 << ND_CMD_SMART | 1 << ND_CMD_SMART_THRESHOLD | 1 << ND_CMD_DIMM_FLAGS \
+ | 1 << ND_CMD_GET_CONFIG_SIZE | 1 << ND_CMD_GET_CONFIG_DATA \
+ | 1 << ND_CMD_SET_CONFIG_DATA | 1 << ND_CMD_VENDOR_EFFECT_LOG_SIZE \
+ | 1 << ND_CMD_VENDOR_EFFECT_LOG | 1 << ND_CMD_VENDOR)
+
 enum nfit_uuids {
 	/* for simplicity alias the uuid index with the family id */
 	NFIT_DEV_DIMM = NVDIMM_FAMILY_INTEL,