libnvdimm: Add DSM support for Address Range Scrub commands

Add support for the three ARS DSM commands:
- Query ARS Capabilities - Queries the firmware to check if a given
  range supports scrub, and if so, which type (persistent vs. volatile)
- Start ARS - Starts a scrub for a given range/type
- Query ARS Status - Checks status of a previously started scrub, and
  provides the error logs if any.

  The commands are described by the example DSM spec at:
  http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

Also add these commands to the nfit_test test framework, and return
canned data.
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/acpi/nfit.c

@@ -868,6 +868,7 @@ static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
 	struct acpi_device *adev;
 	int i;
 
+	nd_desc->dsm_mask = acpi_desc->bus_dsm_force_en;
 	adev = to_acpi_dev(acpi_desc);
 	if (!adev)
 		return;

drivers/acpi/nfit.h

@@ -107,6 +107,7 @@ struct acpi_nfit_desc {
 	struct nvdimm_bus *nvdimm_bus;
 	struct device *dev;
 	unsigned long dimm_dsm_force_en;
+	unsigned long bus_dsm_force_en;
 	int (*blk_do_io)(struct nd_blk_region *ndbr, resource_size_t dpa,
 			void *iobuf, u64 len, int rw);
 };

include/uapi/linux/ndctl.h

@@ -111,6 +111,11 @@ enum {
 	ND_CMD_VENDOR = 9,
 };
 
+enum {
+	ND_ARS_VOLATILE = 1,
+	ND_ARS_PERSISTENT = 2,
+};
+
 static inline const char *nvdimm_bus_cmd_name(unsigned cmd)
 {
 	static const char * const names[] = {
@@ -194,4 +199,9 @@ enum nd_driver_flags {
 enum {
 	ND_MIN_NAMESPACE_SIZE = 0x00400000,
 };
+
+enum ars_masks {
+	ARS_STATUS_MASK = 0x0000FFFF,
+	ARS_EXT_STATUS_SHIFT = 16,
+};
 #endif /* __NDCTL_H__ */

tools/testing/nvdimm/test/nfit.c

@@ -147,75 +147,153 @@ static struct nfit_test *to_nfit_test(struct device *dev)
 	return container_of(pdev, struct nfit_test, pdev);
 }
 
+static int nfit_test_cmd_get_config_size(struct nd_cmd_get_config_size *nd_cmd,
+		unsigned int buf_len)
+{
+	if (buf_len < sizeof(*nd_cmd))
+		return -EINVAL;
+
+	nd_cmd->status = 0;
+	nd_cmd->config_size = LABEL_SIZE;
+	nd_cmd->max_xfer = SZ_4K;
+
+	return 0;
+}
+
+static int nfit_test_cmd_get_config_data(struct nd_cmd_get_config_data_hdr
+		*nd_cmd, unsigned int buf_len, void *label)
+{
+	unsigned int len, offset = nd_cmd->in_offset;
+	int rc;
+
+	if (buf_len < sizeof(*nd_cmd))
+		return -EINVAL;
+	if (offset >= LABEL_SIZE)
+		return -EINVAL;
+	if (nd_cmd->in_length + sizeof(*nd_cmd) > buf_len)
+		return -EINVAL;
+
+	nd_cmd->status = 0;
+	len = min(nd_cmd->in_length, LABEL_SIZE - offset);
+	memcpy(nd_cmd->out_buf, label + offset, len);
+	rc = buf_len - sizeof(*nd_cmd) - len;
+
+	return rc;
+}
+
+static int nfit_test_cmd_set_config_data(struct nd_cmd_set_config_hdr *nd_cmd,
+		unsigned int buf_len, void *label)
+{
+	unsigned int len, offset = nd_cmd->in_offset;
+	u32 *status;
+	int rc;
+
+	if (buf_len < sizeof(*nd_cmd))
+		return -EINVAL;
+	if (offset >= LABEL_SIZE)
+		return -EINVAL;
+	if (nd_cmd->in_length + sizeof(*nd_cmd) + 4 > buf_len)
+		return -EINVAL;
+
+	status = (void *)nd_cmd + nd_cmd->in_length + sizeof(*nd_cmd);
+	*status = 0;
+	len = min(nd_cmd->in_length, LABEL_SIZE - offset);
+	memcpy(label + offset, nd_cmd->in_buf, len);
+	rc = buf_len - sizeof(*nd_cmd) - (len + 4);
+
+	return rc;
+}
+
+static int nfit_test_cmd_ars_cap(struct nd_cmd_ars_cap *nd_cmd,
+		unsigned int buf_len)
+{
+	if (buf_len < sizeof(*nd_cmd))
+		return -EINVAL;
+
+	nd_cmd->max_ars_out = 256;
+	nd_cmd->status = (ND_ARS_PERSISTENT | ND_ARS_VOLATILE) << 16;
+
+	return 0;
+}
+
+static int nfit_test_cmd_ars_start(struct nd_cmd_ars_start *nd_cmd,
+		unsigned int buf_len)
+{
+	if (buf_len < sizeof(*nd_cmd))
+		return -EINVAL;
+
+	nd_cmd->status = 0;
+
+	return 0;
+}
+
+static int nfit_test_cmd_ars_status(struct nd_cmd_ars_status *nd_cmd,
+		unsigned int buf_len)
+{
+	if (buf_len < sizeof(*nd_cmd))
+		return -EINVAL;
+
+	nd_cmd->out_length = 256;
+	nd_cmd->num_records = 0;
+	nd_cmd->status = 0;
+
+	return 0;
+}
+
 static int nfit_test_ctl(struct nvdimm_bus_descriptor *nd_desc,
 		struct nvdimm *nvdimm, unsigned int cmd, void *buf,
 		unsigned int buf_len)
 {
 	struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
 	struct nfit_test *t = container_of(acpi_desc, typeof(*t), acpi_desc);
-	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
-	int i, rc;
+	int i, rc = 0;
+
+	if (nvdimm) {
+		struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
 
-	if (!nfit_mem || !test_bit(cmd, &nfit_mem->dsm_mask))
-		return -ENOTTY;
+		if (!nfit_mem || !test_bit(cmd, &nfit_mem->dsm_mask))
+			return -ENOTTY;
 
-	/* lookup label space for the given dimm */
-	for (i = 0; i < ARRAY_SIZE(handle); i++)
-		if (__to_nfit_memdev(nfit_mem)->device_handle == handle[i])
+		/* lookup label space for the given dimm */
+		for (i = 0; i < ARRAY_SIZE(handle); i++)
+			if (__to_nfit_memdev(nfit_mem)->device_handle ==
+					handle[i])
+				break;
+		if (i >= ARRAY_SIZE(handle))
+			return -ENXIO;
+
+		switch (cmd) {
+		case ND_CMD_GET_CONFIG_SIZE:
+			rc = nfit_test_cmd_get_config_size(buf, buf_len);
 			break;
-	if (i >= ARRAY_SIZE(handle))
-		return -ENXIO;
+		case ND_CMD_GET_CONFIG_DATA:
+			rc = nfit_test_cmd_get_config_data(buf, buf_len,
+				t->label[i]);
+			break;
+		case ND_CMD_SET_CONFIG_DATA:
+			rc = nfit_test_cmd_set_config_data(buf, buf_len,
+				t->label[i]);
+			break;
+		default:
+			return -ENOTTY;
+		}
+	} else {
+		if (!nd_desc || !test_bit(cmd, &nd_desc->dsm_mask))
+			return -ENOTTY;
 
-	switch (cmd) {
-	case ND_CMD_GET_CONFIG_SIZE: {
-		struct nd_cmd_get_config_size *nd_cmd = buf;
-
-		if (buf_len < sizeof(*nd_cmd))
-			return -EINVAL;
-		nd_cmd->status = 0;
-		nd_cmd->config_size = LABEL_SIZE;
-		nd_cmd->max_xfer = SZ_4K;
-		rc = 0;
-		break;
-	}
-	case ND_CMD_GET_CONFIG_DATA: {
-		struct nd_cmd_get_config_data_hdr *nd_cmd = buf;
-		unsigned int len, offset = nd_cmd->in_offset;
-
-		if (buf_len < sizeof(*nd_cmd))
-			return -EINVAL;
-		if (offset >= LABEL_SIZE)
-			return -EINVAL;
-		if (nd_cmd->in_length + sizeof(*nd_cmd) > buf_len)
-			return -EINVAL;
-
-		nd_cmd->status = 0;
-		len = min(nd_cmd->in_length, LABEL_SIZE - offset);
-		memcpy(nd_cmd->out_buf, t->label[i] + offset, len);
-		rc = buf_len - sizeof(*nd_cmd) - len;
-		break;
-	}
-	case ND_CMD_SET_CONFIG_DATA: {
-		struct nd_cmd_set_config_hdr *nd_cmd = buf;
-		unsigned int len, offset = nd_cmd->in_offset;
-		u32 *status;
-
-		if (buf_len < sizeof(*nd_cmd))
-			return -EINVAL;
-		if (offset >= LABEL_SIZE)
-			return -EINVAL;
-		if (nd_cmd->in_length + sizeof(*nd_cmd) + 4 > buf_len)
-			return -EINVAL;
-
-		status = buf + nd_cmd->in_length + sizeof(*nd_cmd);
-		*status = 0;
-		len = min(nd_cmd->in_length, LABEL_SIZE - offset);
-		memcpy(t->label[i] + offset, nd_cmd->in_buf, len);
-		rc = buf_len - sizeof(*nd_cmd) - (len + 4);
-		break;
-	}
-	default:
-		return -ENOTTY;
+		switch (cmd) {
+		case ND_CMD_ARS_CAP:
+			rc = nfit_test_cmd_ars_cap(buf, buf_len);
+			break;
+		case ND_CMD_ARS_START:
+			rc = nfit_test_cmd_ars_start(buf, buf_len);
+			break;
+		case ND_CMD_ARS_STATUS:
+			rc = nfit_test_cmd_ars_status(buf, buf_len);
+			break;
+		default:
+			return -ENOTTY;
+		}
 	}
 
 	return rc;
@@ -876,6 +954,9 @@ static void nfit_test0_setup(struct nfit_test *t)
 	set_bit(ND_CMD_GET_CONFIG_SIZE, &acpi_desc->dimm_dsm_force_en);
 	set_bit(ND_CMD_GET_CONFIG_DATA, &acpi_desc->dimm_dsm_force_en);
 	set_bit(ND_CMD_SET_CONFIG_DATA, &acpi_desc->dimm_dsm_force_en);
+	set_bit(ND_CMD_ARS_CAP, &acpi_desc->bus_dsm_force_en);
+	set_bit(ND_CMD_ARS_START, &acpi_desc->bus_dsm_force_en);
+	set_bit(ND_CMD_ARS_STATUS, &acpi_desc->bus_dsm_force_en);
 	nd_desc = &acpi_desc->nd_desc;
 	nd_desc->ndctl = nfit_test_ctl;
 }