nfit, libnvdimm: clarify "commands" vs "_DSMs"

Clarify the distinction between "commands", the ioctls userspace calls
to request the kernel take some action on a given dimm device, and
"_DSMs", the actual function numbers used in the firmware interface to
the DIMM.  _DSMs are ACPI specific whereas commands are Linux kernel
generic.

This is in preparation for breaking the 1:1 implicit relationship
between the kernel ioctl number space and the firmware specific function
numbers.

Cc: Jerry Hoemann <jerry.hoemann@hpe.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index d0f35e6..1b98e9d 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -175,7 +175,7 @@
 	union acpi_object in_obj, in_buf, *out_obj;
 	struct device *dev = acpi_desc->dev;
 	const char *cmd_name, *dimm_name;
-	unsigned long dsm_mask;
+	unsigned long cmd_mask;
 	acpi_handle handle;
 	const u8 *uuid;
 	u32 offset;
@@ -189,7 +189,7 @@
 			return -ENOTTY;
 		dimm_name = nvdimm_name(nvdimm);
 		cmd_name = nvdimm_cmd_name(cmd);
-		dsm_mask = nfit_mem->dsm_mask;
+		cmd_mask = nvdimm_cmd_mask(nvdimm);
 		desc = nd_cmd_dimm_desc(cmd);
 		uuid = to_nfit_uuid(NFIT_DEV_DIMM);
 		handle = adev->handle;
@@ -197,7 +197,7 @@
 		struct acpi_device *adev = to_acpi_dev(acpi_desc);
 
 		cmd_name = nvdimm_bus_cmd_name(cmd);
-		dsm_mask = nd_desc->dsm_mask;
+		cmd_mask = nd_desc->cmd_mask;
 		desc = nd_cmd_bus_desc(cmd);
 		uuid = to_nfit_uuid(NFIT_DEV_BUS);
 		handle = adev->handle;
@@ -207,7 +207,7 @@
 	if (!desc || (cmd && (desc->out_num + desc->in_num == 0)))
 		return -ENOTTY;
 
-	if (!test_bit(cmd, &dsm_mask))
+	if (!test_bit(cmd, &cmd_mask))
 		return -ENOTTY;
 
 	in_obj.type = ACPI_TYPE_PACKAGE;
@@ -926,7 +926,8 @@
 	const u8 *uuid = to_nfit_uuid(NFIT_DEV_DIMM);
 	int i;
 
-	nfit_mem->dsm_mask = acpi_desc->dimm_dsm_force_en;
+	/* nfit test assumes 1:1 relationship between commands and dsms */
+	nfit_mem->dsm_mask = acpi_desc->dimm_cmd_force_en;
 	adev = to_acpi_dev(acpi_desc);
 	if (!adev)
 		return 0;
@@ -976,9 +977,13 @@
 		if (rc)
 			continue;
 
+		/*
+		 * For now there is 1:1 relationship between cmd_mask and
+		 * dsm_mask.
+		 */
 		nvdimm = nvdimm_create(acpi_desc->nvdimm_bus, nfit_mem,
 				acpi_nfit_dimm_attribute_groups,
-				flags, &nfit_mem->dsm_mask);
+				flags, nfit_mem->dsm_mask);
 		if (!nvdimm)
 			return -ENOMEM;
 
@@ -1007,14 +1012,14 @@
 	struct acpi_device *adev;
 	int i;
 
-	nd_desc->dsm_mask = acpi_desc->bus_dsm_force_en;
+	nd_desc->cmd_mask = acpi_desc->bus_cmd_force_en;
 	adev = to_acpi_dev(acpi_desc);
 	if (!adev)
 		return;
 
 	for (i = ND_CMD_ARS_CAP; i <= ND_CMD_CLEAR_ERROR; i++)
 		if (acpi_check_dsm(adev->handle, uuid, 1, 1ULL << i))
-			set_bit(i, &nd_desc->dsm_mask);
+			set_bit(i, &nd_desc->cmd_mask);
 }
 
 static ssize_t range_index_show(struct device *dev,
diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h
index c75576b..332ee6f 100644
--- a/drivers/acpi/nfit.h
+++ b/drivers/acpi/nfit.h
@@ -132,8 +132,8 @@
 	size_t ars_status_size;
 	struct work_struct work;
 	unsigned int cancel:1;
-	unsigned long dimm_dsm_force_en;
-	unsigned long bus_dsm_force_en;
+	unsigned long dimm_cmd_force_en;
+	unsigned long bus_cmd_force_en;
 	int (*blk_do_io)(struct nd_blk_region *ndbr, resource_size_t dpa,
 			void *iobuf, u64 len, int rw);
 };
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 19f822d..cb2042a 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -589,24 +589,24 @@
 	void __user *p = (void __user *) arg;
 	struct device *dev = &nvdimm_bus->dev;
 	const char *cmd_name, *dimm_name;
-	unsigned long dsm_mask;
+	unsigned long cmd_mask;
 	void *buf;
 	int rc, i;
 
 	if (nvdimm) {
 		desc = nd_cmd_dimm_desc(cmd);
 		cmd_name = nvdimm_cmd_name(cmd);
-		dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
+		cmd_mask = nvdimm->cmd_mask;
 		dimm_name = dev_name(&nvdimm->dev);
 	} else {
 		desc = nd_cmd_bus_desc(cmd);
 		cmd_name = nvdimm_bus_cmd_name(cmd);
-		dsm_mask = nd_desc->dsm_mask;
+		cmd_mask = nd_desc->cmd_mask;
 		dimm_name = "bus";
 	}
 
 	if (!desc || (desc->out_num + desc->in_num == 0) ||
-			!test_bit(cmd, &dsm_mask))
+			!test_bit(cmd, &cmd_mask))
 		return -ENOTTY;
 
 	/* fail write commands (when read-only) */
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 182a93f..e8688a1 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -251,7 +251,7 @@
 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 
-	for_each_set_bit(cmd, &nd_desc->dsm_mask, BITS_PER_LONG)
+	for_each_set_bit(cmd, &nd_desc->cmd_mask, BITS_PER_LONG)
 		len += sprintf(buf + len, "%s ", nvdimm_bus_cmd_name(cmd));
 	len += sprintf(buf + len, "\n");
 	return len;
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index c56f882..79a35a0 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -37,9 +37,9 @@
 
 	nvdimm = to_nvdimm(ndd->dev);
 
-	if (!nvdimm->dsm_mask)
+	if (!nvdimm->cmd_mask)
 		return -ENXIO;
-	if (!test_bit(ND_CMD_GET_CONFIG_DATA, nvdimm->dsm_mask))
+	if (!test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask))
 		return -ENXIO;
 
 	return 0;
@@ -263,6 +263,12 @@
 }
 EXPORT_SYMBOL_GPL(nvdimm_name);
 
+unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm)
+{
+	return nvdimm->cmd_mask;
+}
+EXPORT_SYMBOL_GPL(nvdimm_cmd_mask);
+
 void *nvdimm_provider_data(struct nvdimm *nvdimm)
 {
 	if (nvdimm)
@@ -277,10 +283,10 @@
 	struct nvdimm *nvdimm = to_nvdimm(dev);
 	int cmd, len = 0;
 
-	if (!nvdimm->dsm_mask)
+	if (!nvdimm->cmd_mask)
 		return sprintf(buf, "\n");
 
-	for_each_set_bit(cmd, nvdimm->dsm_mask, BITS_PER_LONG)
+	for_each_set_bit(cmd, &nvdimm->cmd_mask, BITS_PER_LONG)
 		len += sprintf(buf + len, "%s ", nvdimm_cmd_name(cmd));
 	len += sprintf(buf + len, "\n");
 	return len;
@@ -340,7 +346,7 @@
 
 struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
 		const struct attribute_group **groups, unsigned long flags,
-		unsigned long *dsm_mask)
+		unsigned long cmd_mask)
 {
 	struct nvdimm *nvdimm = kzalloc(sizeof(*nvdimm), GFP_KERNEL);
 	struct device *dev;
@@ -355,7 +361,7 @@
 	}
 	nvdimm->provider_data = provider_data;
 	nvdimm->flags = flags;
-	nvdimm->dsm_mask = dsm_mask;
+	nvdimm->cmd_mask = cmd_mask;
 	atomic_set(&nvdimm->busy, 0);
 	dev = &nvdimm->dev;
 	dev_set_name(dev, "nmem%d", nvdimm->id);
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 1d1500f..da0d322 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -37,7 +37,7 @@
 struct nvdimm {
 	unsigned long flags;
 	void *provider_data;
-	unsigned long *dsm_mask;
+	unsigned long cmd_mask;
 	struct device dev;
 	atomic_t busy;
 	int id;