[PATCH] nfit: add Microsoft NVDIMM DSM command set to white list

[Stuart Hayes <stuart.w.hayes@gmail.com>]

Add the Microsoft _DSM command set to the white list of NVDIMM command sets.

This command set is documented at https://msdn.microsoft.com/library/windows/hardware/mt604741.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
---
  drivers/acpi/nfit.c        | 9 ++++++---
  drivers/acpi/nfit.h        | 4 ++++
  include/uapi/linux/ndctl.h | 1 +
  3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 2215fc8..48fc575 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -1130,11 +1130,11 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
  	}
  
  	/*
-	 * Until standardization materializes we need to consider up to 3
+	 * Until standardization materializes we need to consider several
  	 * different command sets.  Note, that checking for function0 (bit0)
  	 * tells us if any commands are reachable through this uuid.
  	 */
-	for (i = NVDIMM_FAMILY_INTEL; i <= NVDIMM_FAMILY_HPE2; i++)
+	for (i = NVDIMM_FAMILY_INTEL; i <= NVDIMM_FAMILY_MSFT; i++)
  		if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 1))
  			break;
  
@@ -1150,7 +1150,9 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
  		dsm_mask = 0x1fe;
  		if (disable_vendor_specific)
  			dsm_mask &= ~(1 << 8);
-	} else {
+	} else if (nfit_mem->family == NVDIMM_FAMILY_MSFT)
+		dsm_mask = 0xffffffff;
+	else {
  		dev_err(dev, "unknown dimm command family\n");
  		nfit_mem->family = -1;
  		return force_enable_dimms ? 0 : -ENODEV;
@@ -2692,6 +2694,7 @@ static __init int nfit_init(void)
  	acpi_str_to_uuid(UUID_NFIT_DIMM, nfit_uuid[NFIT_DEV_DIMM]);
  	acpi_str_to_uuid(UUID_NFIT_DIMM_N_HPE1, nfit_uuid[NFIT_DEV_DIMM_N_HPE1]);
  	acpi_str_to_uuid(UUID_NFIT_DIMM_N_HPE2, nfit_uuid[NFIT_DEV_DIMM_N_HPE2]);
+	acpi_str_to_uuid(UUID_NFIT_DIMM_N_MSFT, nfit_uuid[NFIT_DEV_DIMM_N_MSFT]);
  
  	nfit_wq = create_singlethread_workqueue("nfit");
  	if (!nfit_wq)
diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h
index 11cb383..f06fa91 100644
--- a/drivers/acpi/nfit.h
+++ b/drivers/acpi/nfit.h
@@ -31,6 +31,9 @@
  #define UUID_NFIT_DIMM_N_HPE1 "9002c334-acf3-4c0e-9642-a235f0d53bc6"
  #define UUID_NFIT_DIMM_N_HPE2 "5008664b-b758-41a0-a03c-27c2f2d04f7e"
  
+/* https://msdn.microsoft.com/library/windows/hardware/mt604741 */
+#define UUID_NFIT_DIMM_N_MSFT "1ee68b36-d4bd-4a1a-9a16-4f8e53d46e05"
+
  #define ACPI_NFIT_MEM_FAILED_MASK (ACPI_NFIT_MEM_SAVE_FAILED \
  		| ACPI_NFIT_MEM_RESTORE_FAILED | ACPI_NFIT_MEM_FLUSH_FAILED \
  		| ACPI_NFIT_MEM_NOT_ARMED)
@@ -40,6 +43,7 @@ enum nfit_uuids {
  	NFIT_DEV_DIMM = NVDIMM_FAMILY_INTEL,
  	NFIT_DEV_DIMM_N_HPE1 = NVDIMM_FAMILY_HPE1,
  	NFIT_DEV_DIMM_N_HPE2 = NVDIMM_FAMILY_HPE2,
+	NFIT_DEV_DIMM_N_MSFT = NVDIMM_FAMILY_MSFT,
  	NFIT_SPA_VOLATILE,
  	NFIT_SPA_PM,
  	NFIT_SPA_DCR,
diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h
index 309915f..ba5a8c7 100644
--- a/include/uapi/linux/ndctl.h
+++ b/include/uapi/linux/ndctl.h
@@ -298,6 +298,7 @@ struct nd_cmd_pkg {
  #define NVDIMM_FAMILY_INTEL 0
  #define NVDIMM_FAMILY_HPE1 1
  #define NVDIMM_FAMILY_HPE2 2
+#define NVDIMM_FAMILY_MSFT 3
  
  #define ND_IOCTL_CALL			_IOWR(ND_IOCTL, ND_CMD_CALL,\
  					struct nd_cmd_pkg)
-- 
1.8.3.1