[PATCH 08/10] nvdimm: Add driver for OpenCAPI Storage Class Memory

[Alastair D'Silva]

From: Alastair D'Silva <alastair@xxxxxxxxxxx>

This driver exposes LPC memory on OpenCAPI SCM cards
as an NVDIMM, allowing the existing nvram infrastructure
to be used.

Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
---
 drivers/nvdimm/Kconfig             |   17 +
 drivers/nvdimm/Makefile            |    3 +
 drivers/nvdimm/ocxl-scm.c          | 2210 ++++++++++++++++++++++++++++
 drivers/nvdimm/ocxl-scm_internal.c |  232 +++
 drivers/nvdimm/ocxl-scm_internal.h |  331 +++++
 drivers/nvdimm/ocxl-scm_sysfs.c    |  219 +++
 include/uapi/linux/ocxl-scm.h      |  128 ++
 mm/memory_hotplug.c                |    2 +-
 8 files changed, 3141 insertions(+), 1 deletion(-)
 create mode 100644 drivers/nvdimm/ocxl-scm.c
 create mode 100644 drivers/nvdimm/ocxl-scm_internal.c
 create mode 100644 drivers/nvdimm/ocxl-scm_internal.h
 create mode 100644 drivers/nvdimm/ocxl-scm_sysfs.c
 create mode 100644 include/uapi/linux/ocxl-scm.h

diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 36af7af6b7cf..e4f7b6b08efd 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -130,4 +130,21 @@ config NVDIMM_TEST_BUILD
 	  core devm_memremap_pages() implementation and other
 	  infrastructure.
 
+config OCXL_SCM
+	tristate "OpenCAPI Storage Class Memory"
+	depends on LIBNVDIMM
+	select ZONE_DEVICE
+	select OCXL
+	help
+	  Exposes devices that implement the OpenCAPI Storage Class Memory
+	  specification as persistent memory regions.
+
+	  Select N if unsure.
+
+config OCXL_SCM_DEBUG
+	bool "OpenCAPI Storage Class Memory debugging"
+	depends on OCXL_SCM
+	help
+	  Enables low level IOCTLs for OpenCAPI SCM firmware development
+
 endif
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index 29203f3d3069..43d826397bfc 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -6,6 +6,9 @@ obj-$(CONFIG_ND_BLK) += nd_blk.o
 obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
 obj-$(CONFIG_OF_PMEM) += of_pmem.o
 obj-$(CONFIG_VIRTIO_PMEM) += virtio_pmem.o nd_virtio.o
+obj-$(CONFIG_OCXL_SCM) += ocxlscm.o
+
+ocxlscm-y := ocxl-scm.o ocxl-scm_internal.o ocxl-scm_sysfs.o
 
 nd_pmem-y := pmem.o
 
diff --git a/drivers/nvdimm/ocxl-scm.c b/drivers/nvdimm/ocxl-scm.c
new file mode 100644
index 000000000000..f4e6cc022de8
--- /dev/null
+++ b/drivers/nvdimm/ocxl-scm.c
@@ -0,0 +1,2210 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2019 IBM Corp.
+
+/*
+ * A driver for Storage Class Memory, connected via OpenCAPI
+ */
+
+#include <linux/module.h>
+#include <misc/ocxl.h>
+#include <linux/delay.h>
+#include <linux/ndctl.h>
+#include <linux/eventfd.h>
+#include <linux/fs.h>
+#include <linux/mm_types.h>
+#include <linux/memory_hotplug.h>
+#include "ocxl-scm_internal.h"
+
+
+static const struct pci_device_id scm_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x0625), },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(pci, scm_pci_tbl);
+
+#define SCM_NUM_MINORS 256 // Total to reserve
+#define SCM_USABLE_TIMEOUT 120 // seconds
+
+static dev_t scm_dev;
+static struct class *scm_class;
+static struct mutex minors_idr_lock;
+static struct idr minors_idr;
+
+static const struct attribute_group *scm_pmem_attribute_groups[] = {
+	&nvdimm_bus_attribute_group,
+	NULL,
+};
+
+static const struct attribute_group *scm_pmem_region_attribute_groups[] = {
+	&nd_region_attribute_group,
+	&nd_device_attribute_group,
+	&nd_mapping_attribute_group,
+	&nd_numa_attribute_group,
+	NULL,
+};
+
+/**
+ * scm_ndctl_config_write() - Handle a ND_CMD_SET_CONFIG_DATA command from ndctl
+ * @scm_data: the SCM metadata
+ * @command: the incoming data to write
+ * Return: 0 on success, negative on failure
+ */
+static int scm_ndctl_config_write(struct scm_data *scm_data,
+				  struct nd_cmd_set_config_hdr *command)
+{
+	if (command->in_offset + command->in_length > SCM_LABEL_AREA_SIZE)
+		return -EINVAL;
+
+	memcpy_flushcache(scm_data->metadata_addr + command->in_offset, command->in_buf,
+			  command->in_length);
+
+	return 0;
+}
+
+/**
+ * scm_ndctl_config_read() - Handle a ND_CMD_GET_CONFIG_DATA command from ndctl
+ * @scm_data: the SCM metadata
+ * @command: the read request
+ * Return: 0 on success, negative on failure
+ */
+static int scm_ndctl_config_read(struct scm_data *scm_data,
+				 struct nd_cmd_get_config_data_hdr *command)
+{
+	if (command->in_offset + command->in_length > SCM_LABEL_AREA_SIZE)
+		return -EINVAL;
+
+	memcpy(command->out_buf, scm_data->metadata_addr + command->in_offset,
+	       command->in_length);
+
+	return 0;
+}
+
+/**
+ * scm_ndctl_config_size() - Handle a ND_CMD_GET_CONFIG_SIZE command from ndctl
+ * @scm_data: the SCM metadata
+ * @command: the read request
+ * Return: 0 on success, negative on failure
+ */
+static int scm_ndctl_config_size(struct nd_cmd_get_config_size *command)
+{
+	command->status = 0;
+	command->config_size = SCM_LABEL_AREA_SIZE;
+	command->max_xfer = PAGE_SIZE;
+
+	return 0;
+}
+
+static int read_smart_attrib(struct scm_data *scm_data, u16 offset,
+			     struct scm_smart_attribs *attribs)
+{
+	u64 val;
+	int rc;
+	struct scm_smart_attrib *attrib;
+	u8 attrib_id;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, offset, OCXL_LITTLE_ENDIAN,
+				     &val);
+	if (rc)
+		return rc;
+
+	attrib_id = (val >> 56) & 0xff;
+	switch (attrib_id) {
+	case SCM_SMART_ATTR_POWER_ON_HOURS:
+		attrib = &attribs->power_on_hours;
+		break;
+
+	case SCM_SMART_ATTR_TEMPERATURE:
+		attrib = &attribs->temperature;
+		break;
+
+	case SCM_SMART_ATTR_LIFE_REMAINING:
+		attrib = &attribs->life_remaining;
+		break;
+
+	default:
+		dev_err(&scm_data->dev, "Unknown smart attrib '%d'", attrib_id);
+		return -EFAULT;
+	}
+
+	attrib->id = attrib_id;
+	attrib->attribute_flags = (val >> 40) & 0xffff;
+	attrib->current_val = (val >> 32) & 0xff;
+	attrib->threshold_val = (val >> 24) & 0xff;
+	attrib->worst_val = (val >> 16) & 0xff;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, offset + 0x08,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	attrib->raw_val = val;
+
+	return 0;
+}
+
+static int scm_smart_offset_0x00(struct scm_data *scm_data, u32 *length)
+{
+	int rc;
+	u64 val;
+
+	u16 data_identifier;
+	u32 data_length;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	data_identifier = val >> 48;
+	data_length = val & 0xFFFFFFFF;
+
+	if (data_identifier != 0x534D) {
+		dev_err(&scm_data->dev,
+			"Bad data identifier for smart data, expected 'SM', got '%-.*s'\n",
+			2, (char *)&data_identifier);
+		return -EFAULT;
+	}
+
+	*length = data_length;
+	return 0;
+}
+
+static int scm_smart_update(struct scm_data *scm_data)
+{
+	u32 length, i;
+	int rc;
+
+	mutex_lock(&scm_data->admin_command.lock);
+
+	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_SMART);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_execute(scm_data);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_complete_timeout(scm_data, ADMIN_COMMAND_SMART);
+	if (rc < 0) {
+		dev_err(&scm_data->dev, "SMART timeout\n");
+		goto out;
+	}
+
+	rc = scm_admin_response(scm_data);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS) {
+		scm_warn_status(scm_data, "Unexpected status from SMART", rc);
+		goto out;
+	}
+
+	rc = scm_smart_offset_0x00(scm_data, &length);
+	if (rc)
+		goto out;
+
+	length /= 0x10; // Length now contains the number of attributes
+
+	for (i = 0; i < length; i++)
+		read_smart_attrib(scm_data,
+				  scm_data->admin_command.data_offset + 0x08 + i * 0x10,
+				  &scm_data->smart);
+
+	rc = scm_admin_response_handled(scm_data);
+	if (rc)
+		goto out;
+
+	rc = 0;
+	goto out;
+
+out:
+	mutex_unlock(&scm_data->admin_command.lock);
+	return rc;
+}
+
+static int scm_ndctl_smart(struct scm_data *scm_data, void *buf,
+			   unsigned int buf_len)
+{
+	int rc;
+
+	if (buf_len != sizeof(scm_data->smart))
+		return -EINVAL;
+
+	rc = scm_smart_update(scm_data);
+	if (rc)
+		return rc;
+
+	memcpy(buf, &scm_data->smart, buf_len);
+
+	return 0;
+}
+
+
+static int scm_ndctl(struct nvdimm_bus_descriptor *nd_desc,
+		     struct nvdimm *nvdimm,
+		     unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
+{
+	struct scm_data *scm_data = container_of(nd_desc, struct scm_data, bus_desc);
+
+	switch (cmd) {
+	case ND_CMD_SMART:
+		*cmd_rc = scm_ndctl_smart(scm_data, buf, buf_len);
+		return 0;
+
+	case ND_CMD_GET_CONFIG_SIZE:
+		*cmd_rc = scm_ndctl_config_size(buf);
+		return 0;
+
+	case ND_CMD_GET_CONFIG_DATA:
+		*cmd_rc = scm_ndctl_config_read(scm_data, buf);
+		return 0;
+
+	case ND_CMD_SET_CONFIG_DATA:
+		*cmd_rc = scm_ndctl_config_write(scm_data, buf);
+		return 0;
+
+	default:
+		return -ENOTTY;
+	}
+}
+
+static ssize_t serial_show(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct nvdimm *nvdimm = to_nvdimm(dev);
+	struct scm_data *scm_data = nvdimm_provider_data(nvdimm);
+	const struct ocxl_fn_config *config = ocxl_function_config(scm_data->ocxl_fn);
+
+	return sprintf(buf, "0x%llx\n", config->serial);
+}
+static DEVICE_ATTR_RO(serial);
+
+static struct attribute *scm_dimm_attributes[] = {
+	&dev_attr_serial.attr,
+	NULL,
+};
+
+static umode_t scm_dimm_attr_visible(struct kobject *kobj,
+				     struct attribute *a, int n)
+{
+	return a->mode;
+}
+
+static const struct attribute_group scm_dimm_attribute_group = {
+	.name = "scm",
+	.attrs = scm_dimm_attributes,
+	.is_visible = scm_dimm_attr_visible,
+};
+
+static const struct attribute_group *scm_dimm_attribute_groups[] = {
+	&nvdimm_attribute_group,
+	&nd_device_attribute_group,
+	&scm_dimm_attribute_group,
+	NULL,
+};
+
+/**
+ * scm_reserve_metadata() - Reserve space for nvdimm metadata
+ * @scm_data: The SCM device data
+ * @lpc_mem: The resource representing the LPC memory of the SCM device
+ */
+static int scm_reserve_metadata(struct scm_data *scm_data,
+				struct resource *lpc_mem)
+{
+	scm_data->metadata_addr = devm_memremap(&scm_data->dev, lpc_mem->start,
+						SCM_LABEL_AREA_SIZE, MEMREMAP_WB);
+	if (IS_ERR(scm_data->metadata_addr))
+		return PTR_ERR(scm_data->metadata_addr);
+
+	return 0;
+}
+
+/**
+ * scm_overwrite() - Overwrite all data on the card
+ * @scm_data: The SCM device data
+ * Return: 0 on success
+ */
+int scm_overwrite(struct scm_data *scm_data)
+{
+	int rc;
+
+	mutex_lock(&scm_data->ns_command.lock);
+
+	rc = scm_ns_command_request(scm_data, NS_COMMAND_SECURE_ERASE);
+	if (rc)
+		goto out;
+
+	rc = scm_ns_command_execute(scm_data);
+	if (rc)
+		goto out;
+
+	scm_data->overwrite_state = SCM_OVERWRITE_BUSY;
+
+	return 0;
+
+out:
+	mutex_unlock(&scm_data->ns_command.lock);
+	return rc;
+}
+
+/**
+ * scm_secop_overwrite() - Overwrite all data on the card
+ * @nvdimm: The nvdimm representation of the SCM device to start the overwrite on
+ * @key_data: Unused (no security key implementation)
+ * Return: 0 on success
+ */
+static int scm_secop_overwrite(struct nvdimm *nvdimm,
+			       const struct nvdimm_key_data *key_data)
+{
+	struct scm_data *scm_data = nvdimm_provider_data(nvdimm);
+
+	return scm_overwrite(scm_data);
+}
+
+/**
+ * scm_secop_query_overwrite() - Get the current overwrite state
+ * @nvdimm: The nvdimm representation of the SCM device to start the overwrite on
+ * Return: 0 if successful or idle, -EBUSY if busy, -EFAULT if failed
+ */
+static int scm_secop_query_overwrite(struct nvdimm *nvdimm)
+{
+	struct scm_data *scm_data = nvdimm_provider_data(nvdimm);
+
+	if (scm_data->overwrite_state == SCM_OVERWRITE_BUSY)
+		return -EBUSY;
+
+	if (scm_data->overwrite_state == SCM_OVERWRITE_FAILED)
+		return -EFAULT;
+
+	return 0;
+}
+
+/**
+ * scm_secop_get_flags() - return the security flags for the SCM device
+ */
+static unsigned long scm_secop_get_flags(struct nvdimm *nvdimm,
+		enum nvdimm_passphrase_type ptype)
+{
+	struct scm_data *scm_data = nvdimm_provider_data(nvdimm);
+
+	if (scm_data->overwrite_state == SCM_OVERWRITE_BUSY)
+		return BIT(NVDIMM_SECURITY_OVERWRITE);
+
+	return BIT(NVDIMM_SECURITY_DISABLED);
+}
+
+static const struct nvdimm_security_ops sec_ops  = {
+	.get_flags = scm_secop_get_flags,
+	.overwrite = scm_secop_overwrite,
+	.query_overwrite = scm_secop_query_overwrite,
+};
+
+/**
+ * scm_register_lpc_mem() - Discover persistent memory on a device and register it with the NVDIMM subsystem
+ * @scm_data: The SCM device data
+ * Return: 0 on success
+ */
+static int scm_register_lpc_mem(struct scm_data *scm_data)
+{
+	struct nd_region_desc region_desc;
+	struct nd_mapping_desc nd_mapping_desc;
+	struct resource *lpc_mem;
+	const struct ocxl_afu_config *config;
+	const struct ocxl_fn_config *fn_config;
+	int rc;
+	unsigned long nvdimm_cmd_mask = 0;
+	unsigned long nvdimm_flags = 0;
+	int target_node;
+	char serial[16+1];
+
+	// Set up the reserved metadata area
+	rc = ocxl_afu_map_lpc_mem(scm_data->ocxl_afu);
+	if (rc < 0)
+		return rc;
+
+	lpc_mem = ocxl_afu_lpc_mem(scm_data->ocxl_afu);
+	if (lpc_mem == NULL)
+		return -EINVAL;
+
+	config = ocxl_afu_config(scm_data->ocxl_afu);
+	fn_config = ocxl_function_config(scm_data->ocxl_fn);
+
+	rc = scm_reserve_metadata(scm_data, lpc_mem);
+	if (rc)
+		return rc;
+
+	scm_data->bus_desc.attr_groups = scm_pmem_attribute_groups;
+	scm_data->bus_desc.provider_name = "scm";
+	scm_data->bus_desc.ndctl = scm_ndctl;
+	scm_data->bus_desc.module = THIS_MODULE;
+
+	scm_data->nvdimm_bus = nvdimm_bus_register(&scm_data->dev,
+			       &scm_data->bus_desc);
+	if (!scm_data->nvdimm_bus)
+		return -EINVAL;
+
+	scm_data->scm_res.start = (u64)lpc_mem->start + SCM_LABEL_AREA_SIZE;
+	scm_data->scm_res.end = (u64)lpc_mem->start + config->lpc_mem_size - 1;
+	scm_data->scm_res.name = "SCM persistent memory";
+
+	set_bit(ND_CMD_GET_CONFIG_SIZE, &nvdimm_cmd_mask);
+	set_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm_cmd_mask);
+	set_bit(ND_CMD_SET_CONFIG_DATA, &nvdimm_cmd_mask);
+	set_bit(ND_CMD_SMART, &nvdimm_cmd_mask);
+
+	set_bit(NDD_ALIASING, &nvdimm_flags);
+
+	snprintf(serial, sizeof(serial), "%llx", fn_config->serial);
+	nd_mapping_desc.nvdimm = __nvdimm_create(scm_data->nvdimm_bus, scm_data,
+				 scm_dimm_attribute_groups,
+				 nvdimm_flags, nvdimm_cmd_mask,
+				 0, NULL, serial, &sec_ops);
+	if (!nd_mapping_desc.nvdimm)
+		return -ENOMEM;
+
+	if (nvdimm_bus_check_dimm_count(scm_data->nvdimm_bus, 1))
+		return -EINVAL;
+
+	nd_mapping_desc.start = scm_data->scm_res.start;
+	nd_mapping_desc.size = resource_size(&scm_data->scm_res);
+	nd_mapping_desc.position = 0;
+
+	scm_data->nd_set.cookie1 = fn_config->serial + 1; // allow for empty serial
+	scm_data->nd_set.cookie2 = fn_config->serial + 1;
+
+	target_node = of_node_to_nid(scm_data->pdev->dev.of_node);
+
+	memset(&region_desc, 0, sizeof(region_desc));
+	region_desc.res = &scm_data->scm_res;
+	region_desc.attr_groups = scm_pmem_region_attribute_groups;
+	region_desc.numa_node = NUMA_NO_NODE;
+	region_desc.target_node = target_node;
+	region_desc.num_mappings = 1;
+	region_desc.mapping = &nd_mapping_desc;
+	region_desc.nd_set = &scm_data->nd_set;
+
+	set_bit(ND_REGION_PAGEMAP, &region_desc.flags);
+	/*
+	 * NB: libnvdimm copies the data from ndr_desc into it's own
+	 * structures so passing a stack pointer is fine.
+	 */
+	scm_data->nd_region = nvdimm_pmem_region_create(scm_data->nvdimm_bus,
+			      &region_desc);
+	if (!scm_data->nd_region)
+		return -EINVAL;
+
+	dev_info(&scm_data->dev,
+		 "Onlining %lluMB of persistent memory\n",
+		 nd_mapping_desc.size / SZ_1M);
+
+	return 0;
+}
+
+/**
+ * scm_is_memory_available() - Does the controller have memory available?
+ * @scm_data: a pointer to the SCM device data
+ * Return: true if the controller has memory available
+ */
+static bool scm_is_memory_available(const struct scm_data *scm_data)
+{
+	u64 val = 0;
+	int rc = scm_chi(scm_data, &val);
+
+	WARN_ON(rc < 0);
+
+	return (val & GLOBAL_MMIO_CHI_MA) != 0;
+}
+
+/**
+ * scm_extract_command_metadata() - Extract command data from MMIO & save it for further use
+ * @scm_data: a pointer to the SCM device data
+ * @offset: The base address of the command data structures (address of CREQO)
+ * @command_metadata: A pointer to the command metadata to populate
+ * Return: 0 on success, negative on failure
+ */
+static int scm_extract_command_metadata(struct scm_data *scm_data, u32 offset,
+					struct command_metadata *command_metadata)
+{
+	int rc;
+	u64 tmp;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, offset, OCXL_LITTLE_ENDIAN,
+				     &tmp);
+	if (rc)
+		return rc;
+
+	command_metadata->request_offset = tmp >> 32;
+	command_metadata->response_offset = tmp & 0xFFFFFFFF;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, offset + 8, OCXL_LITTLE_ENDIAN,
+				     &tmp);
+	if (rc)
+		return rc;
+
+	command_metadata->data_offset = tmp >> 32;
+	command_metadata->data_size = tmp & 0xFFFFFFFF;
+
+	command_metadata->id = 0;
+
+	return 0;
+}
+
+/**
+ * scm_setup_command_metadata() - Set up the command metadata
+ * @scm_data: a pointer to the SCM device data
+ */
+static int scm_setup_command_metadata(struct scm_data *scm_data)
+{
+	int rc;
+
+	rc = scm_extract_command_metadata(scm_data, GLOBAL_MMIO_ACMA_CREQO,
+					  &scm_data->admin_command);
+	if (rc)
+		return rc;
+
+	rc = scm_extract_command_metadata(scm_data, GLOBAL_MMIO_NSCMA_CREQO,
+					  &scm_data->ns_command);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+/**
+ * scm_heartbeat() - Issue a heartbeat command to the controller
+ * @scm_data: a pointer to the SCM device data
+ * Return: 0 if the controller responded correctly, negative on error
+ */
+static int scm_heartbeat(struct scm_data *scm_data)
+{
+	int rc;
+
+	mutex_lock(&scm_data->admin_command.lock);
+
+	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_HEARTBEAT);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_execute(scm_data);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_complete_timeout(scm_data, ADMIN_COMMAND_HEARTBEAT);
+	if (rc < 0) {
+		dev_err(&scm_data->dev, "Heartbeat timeout\n");
+		goto out;
+	}
+
+	rc = scm_admin_response(scm_data);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS)
+		scm_warn_status(scm_data, "Unexpected status from heartbeat", rc);
+
+	rc = scm_admin_response_handled(scm_data);
+
+	goto out;
+
+out:
+	mutex_unlock(&scm_data->admin_command.lock);
+	return rc;
+}
+
+/**
+ * scm_is_usable() - Is a controller usable?
+ * @scm_data: a pointer to the SCM device data
+ * Return: true if the controller is usable
+ */
+static bool scm_is_usable(const struct scm_data *scm_data)
+{
+	if (!scm_controller_is_ready(scm_data)) {
+		dev_err(&scm_data->dev, "SCM controller is not ready.\n");
+		return false;
+	}
+
+	if (!scm_is_memory_available(scm_data)) {
+		dev_err(&scm_data->dev,
+			"SCM controller does not have memory available.\n");
+		return false;
+	}
+
+	return true;
+}
+
+/**
+ * allocate_scm_minor() - Allocate a minor number to use for an SCM device
+ * @scm_data: The SCM device to associate the minor with
+ * Return: the allocated minor number
+ */
+static int allocate_scm_minor(struct scm_data *scm_data)
+{
+	int minor;
+
+	mutex_lock(&minors_idr_lock);
+	minor = idr_alloc(&minors_idr, scm_data, 0, SCM_NUM_MINORS, GFP_KERNEL);
+	mutex_unlock(&minors_idr_lock);
+	return minor;
+}
+
+static void free_scm_minor(struct scm_data *scm_data)
+{
+	mutex_lock(&minors_idr_lock);
+	idr_remove(&minors_idr, MINOR(scm_data->dev.devt));
+	mutex_unlock(&minors_idr_lock);
+}
+
+/**
+ * free_scm() - Free all members of an SCM struct
+ * @scm_data: the SCM metadata to clear
+ */
+static void free_scm(struct scm_data *scm_data)
+{
+	// Disable doorbells
+	(void)ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_CHIEC,
+				     OCXL_LITTLE_ENDIAN,
+				     GLOBAL_MMIO_CHI_ALL);
+
+	free_scm_minor(scm_data);
+
+	if (scm_data->irq_addr[1])
+		iounmap(scm_data->irq_addr[1]);
+
+	if (scm_data->irq_addr[0])
+		iounmap(scm_data->irq_addr[0]);
+
+	if (scm_data->cdev.owner)
+		cdev_del(&scm_data->cdev);
+
+	if (scm_data->metadata_addr)
+		devm_memunmap(&scm_data->dev, scm_data->metadata_addr);
+
+	if (scm_data->ocxl_context)
+		ocxl_context_free(scm_data->ocxl_context);
+
+	if (scm_data->ocxl_afu)
+		ocxl_afu_put(scm_data->ocxl_afu);
+
+	if (scm_data->ocxl_fn)
+		ocxl_function_close(scm_data->ocxl_fn);
+
+	kfree(scm_data);
+}
+
+/**
+ * free_scm_dev - Free an SCM device
+ * @dev: The device struct
+ */
+static void free_scm_dev(struct device *dev)
+{
+	struct scm_data *scm_data = container_of(dev, struct scm_data, dev);
+
+	free_scm(scm_data);
+}
+
+/**
+ * scm_register - Register an SCM device with the kernel
+ * @scm_data: the SCM metadata
+ * Return: 0 on success, negative on failure
+ */
+static int scm_register(struct scm_data *scm_data)
+{
+	int rc;
+	int minor = allocate_scm_minor(scm_data);
+
+	if (minor < 0)
+		return minor;
+
+	scm_data->dev.release = free_scm_dev;
+	rc = dev_set_name(&scm_data->dev, "scm%d", minor);
+	if (rc < 0)
+		return rc;
+
+	scm_data->dev.devt = MKDEV(MAJOR(scm_dev), minor);
+	scm_data->dev.class = scm_class;
+	scm_data->dev.parent = &scm_data->pdev->dev;
+
+	rc = device_register(&scm_data->dev);
+	return rc;
+}
+
+static void scm_put(struct scm_data *scm_data)
+{
+	put_device(&scm_data->dev);
+}
+
+struct scm_data *scm_get(struct scm_data *scm_data)
+{
+	return (get_device(&scm_data->dev) == NULL) ? NULL : scm_data;
+}
+
+static struct scm_data *find_and_get_scm(dev_t devno)
+{
+	struct scm_data *scm_data;
+	int minor = MINOR(devno);
+	/*
+	 * We don't declare an RCU critical section here, as our AFU
+	 * is protected by a reference counter on the device. By the time the
+	 * minor number of a device is removed from the idr, the ref count of
+	 * the device is already at 0, so no user API will access that AFU and
+	 * this function can't return it.
+	 */
+	scm_data = idr_find(&minors_idr, minor);
+	if (scm_data)
+		scm_get(scm_data);
+	return scm_data;
+}
+
+static int scm_file_open(struct inode *inode, struct file *file)
+{
+	struct scm_data *scm_data;
+
+	scm_data = find_and_get_scm(inode->i_rdev);
+	if (!scm_data)
+		return -ENODEV;
+
+	file->private_data = scm_data;
+	return 0;
+}
+
+static int scm_file_release(struct inode *inode, struct file *file)
+{
+	struct scm_data *scm_data = file->private_data;
+
+	if (scm_data->ev_ctx) {
+		eventfd_ctx_put(scm_data->ev_ctx);
+		scm_data->ev_ctx = NULL;
+	}
+
+	scm_put(scm_data);
+	return 0;
+}
+
+static int scm_ioctl_buffer_info(struct scm_data *scm_data,
+				 struct scm_ioctl_buffer_info __user *uarg)
+{
+	struct scm_ioctl_buffer_info args;
+
+	args.admin_command_buffer_size = scm_data->admin_command.data_size;
+	args.near_storage_buffer_size = scm_data->ns_command.data_size;
+
+	if (copy_to_user(uarg, &args, sizeof(args)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int scm_error_log_offset_0x00(struct scm_data *scm_data, u16 *length)
+{
+	int rc;
+	u64 val;
+
+	u16 data_identifier;
+	u32 data_length;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	data_identifier = val >> 48;
+	data_length = val & 0xFFFF;
+
+	if (data_identifier != 0x454C) {
+		dev_err(&scm_data->dev,
+			"Bad data identifier for error log data, expected 'EL', got '%2s' (%#x), data_length=%u\n",
+			(char *)&data_identifier,
+			(unsigned int)data_identifier, data_length);
+		return -EFAULT;
+	}
+
+	*length = data_length;
+	return 0;
+}
+
+static int scm_error_log_offset_0x08(struct scm_data *scm_data,
+				     u32 *log_identifier, u32 *program_ref_code)
+{
+	int rc;
+	u64 val;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	*log_identifier = val >> 32;
+	*program_ref_code = val & 0xFFFFFFFF;
+
+	return 0;
+}
+
+static int scm_read_error_log(struct scm_data *scm_data,
+			      struct scm_ioctl_error_log *log, bool buf_is_user)
+{
+	u64 val;
+	u16 user_buf_length;
+	u16 buf_length;
+	u16 i;
+	int rc;
+
+	if (log->buf_size % 8)
+		return -EINVAL;
+
+	rc = scm_chi(scm_data, &val);
+	if (rc)
+		goto out;
+
+	if (!(val & GLOBAL_MMIO_CHI_ELA))
+		return -EAGAIN;
+
+	user_buf_length = log->buf_size;
+
+	mutex_lock(&scm_data->admin_command.lock);
+
+	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_ERRLOG);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_execute(scm_data);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_complete_timeout(scm_data, ADMIN_COMMAND_ERRLOG);
+	if (rc < 0) {
+		dev_warn(&scm_data->dev, "Read error log timed out\n");
+		goto out;
+	}
+
+	rc = scm_admin_response(scm_data);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS) {
+		scm_warn_status(scm_data, "Unexpected status from retrieve error log", rc);
+		goto out;
+	}
+
+
+	rc = scm_error_log_offset_0x00(scm_data, &log->buf_size);
+	if (rc)
+		goto out;
+	// log->buf_size now contains the scm buffer size, not the user size
+
+	rc = scm_error_log_offset_0x08(scm_data, &log->log_identifier,
+				       &log->program_reference_code);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x10,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		goto out;
+
+	log->error_log_type = val >> 56;
+	log->action_flags = (log->error_log_type == SCM_ERROR_LOG_TYPE_GENERAL) ?
+			    (val >> 32) & 0xFFFFFF : 0;
+	log->power_on_seconds = val & 0xFFFFFFFF;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x18,
+				     OCXL_LITTLE_ENDIAN, &log->timestamp);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x20,
+				     OCXL_HOST_ENDIAN, &log->wwid[0]);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x28,
+				     OCXL_HOST_ENDIAN, &log->wwid[1]);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x30,
+				     OCXL_HOST_ENDIAN, (u64 *)log->fw_revision);
+	if (rc)
+		goto out;
+	log->fw_revision[8] = '\0';
+
+	buf_length = (user_buf_length < log->buf_size) ?
+		     user_buf_length : log->buf_size;
+	for (i = 0; i < buf_length + 0x48; i += 8) {
+		u64 val;
+
+		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+					     scm_data->admin_command.data_offset + i,
+					     OCXL_HOST_ENDIAN, &val);
+		if (rc)
+			goto out;
+
+		if (buf_is_user) {
+			if (copy_to_user(&log->buf[i], &val, sizeof(u64))) {
+				rc = -EFAULT;
+				goto out;
+			}
+		} else
+			log->buf[i] = val;
+	}
+
+	rc = scm_admin_response_handled(scm_data);
+	if (rc)
+		goto out;
+
+out:
+	mutex_unlock(&scm_data->admin_command.lock);
+	return rc;
+
+}
+
+static int scm_ioctl_error_log(struct scm_data *scm_data,
+			       struct scm_ioctl_error_log __user *uarg)
+{
+	struct scm_ioctl_error_log args;
+	int rc;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	rc = scm_read_error_log(scm_data, &args, true);
+	if (rc)
+		return rc;
+
+	if (copy_to_user(uarg, &args, sizeof(args)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int scm_ioctl_controller_dump_data(struct scm_data *scm_data,
+	struct scm_ioctl_controller_dump_data __user *uarg)
+{
+	struct scm_ioctl_controller_dump_data args;
+	u16 i;
+	u64 val;
+	int rc;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	if (args.buf_size % 8)
+		return -EINVAL;
+
+	if (args.buf_size > scm_data->admin_command.data_size)
+		return -EINVAL;
+
+	mutex_lock(&scm_data->admin_command.lock);
+
+	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_CONTROLLER_DUMP);
+	if (rc)
+		goto out;
+
+	val = ((u64)args.offset) << 32;
+	val |= args.buf_size;
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+				      scm_data->admin_command.request_offset + 0x08,
+				      OCXL_LITTLE_ENDIAN, val);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_execute(scm_data);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_complete_timeout(scm_data,
+						ADMIN_COMMAND_CONTROLLER_DUMP);
+	if (rc < 0) {
+		dev_warn(&scm_data->dev, "Controller dump timed out\n");
+		goto out;
+	}
+
+	rc = scm_admin_response(scm_data);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS) {
+		scm_warn_status(scm_data,
+				"Unexpected status from retrieve error log",
+				rc);
+		goto out;
+	}
+
+	for (i = 0; i < args.buf_size; i += 8) {
+		u64 val;
+
+		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+					     scm_data->admin_command.data_offset + i,
+					     OCXL_HOST_ENDIAN, &val);
+		if (rc)
+			goto out;
+
+		if (copy_to_user(&args.buf[i], &val, sizeof(u64))) {
+			rc = -EFAULT;
+			goto out;
+		}
+	}
+
+	if (copy_to_user(uarg, &args, sizeof(args))) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	rc = scm_admin_response_handled(scm_data);
+	if (rc)
+		goto out;
+
+out:
+	mutex_unlock(&scm_data->admin_command.lock);
+	return rc;
+}
+
+int scm_request_controller_dump(struct scm_data *scm_data)
+{
+	int rc;
+	u64 busy = 1;
+
+	rc = ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_CHIC,
+				    OCXL_LITTLE_ENDIAN,
+				    GLOBAL_MMIO_CHI_CDA);
+
+
+	rc = ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+				    OCXL_LITTLE_ENDIAN,
+				    GLOBAL_MMIO_HCI_CONTROLLER_DUMP);
+	if (rc)
+		return rc;
+
+	while (busy) {
+		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+					     GLOBAL_MMIO_HCI,
+					     OCXL_LITTLE_ENDIAN, &busy);
+		if (rc)
+			return rc;
+
+		busy &= GLOBAL_MMIO_HCI_CONTROLLER_DUMP;
+		cond_resched();
+	}
+
+	return 0;
+}
+
+static int scm_ioctl_controller_dump_complete(struct scm_data *scm_data)
+{
+	int rc;
+
+	rc = ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+				    OCXL_LITTLE_ENDIAN,
+				    GLOBAL_MMIO_HCI_CONTROLLER_DUMP_COLLECTED);
+
+	if (rc)
+		return -EFAULT;
+
+	return 0;
+}
+
+static int scm_controller_stats_offset_0x00(struct scm_data *scm_data,
+	u32 *length)
+{
+	int rc;
+	u64 val;
+
+	u16 data_identifier;
+	u32 data_length;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	data_identifier = val >> 48;
+	data_length = val & 0xFFFFFFFF;
+
+	if (data_identifier != 0x4353) {
+		dev_err(&scm_data->dev,
+			"Bad data identifier for controller stats, expected 'CS', got '%-.*s'\n",
+			2, (char *)&data_identifier);
+		return -EFAULT;
+	}
+
+	*length = data_length;
+	return 0;
+}
+
+static int scm_ioctl_controller_stats(struct scm_data *scm_data,
+				      struct scm_ioctl_controller_stats __user *uarg)
+{
+	struct scm_ioctl_controller_stats args;
+	u32 length;
+	int rc;
+	u64 val;
+
+	memset(&args, '\0', sizeof(args));
+
+	mutex_lock(&scm_data->admin_command.lock);
+
+	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_CONTROLLER_STATS);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+				      scm_data->admin_command.request_offset + 0x08,
+				      OCXL_LITTLE_ENDIAN, 0);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_execute(scm_data);
+	if (rc)
+		goto out;
+
+
+	rc = scm_admin_command_complete_timeout(scm_data,
+						ADMIN_COMMAND_CONTROLLER_STATS);
+	if (rc < 0) {
+		dev_warn(&scm_data->dev, "Controller stats timed out\n");
+		goto out;
+	}
+
+	rc = scm_admin_response(scm_data);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS) {
+		scm_warn_status(scm_data,
+				"Unexpected status from controller stats", rc);
+		goto out;
+	}
+
+	rc = scm_controller_stats_offset_0x00(scm_data, &length);
+	if (rc)
+		goto out;
+
+	if (length != 0x140)
+		scm_warn_status(scm_data,
+				"Unexpected length for controller stats data, expected 0x140, got 0x%x",
+				length);
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x08,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		goto out;
+
+	args.reset_count = val >> 32;
+	args.reset_uptime = val & 0xFFFFFFFF;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x10,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		goto out;
+
+	args.power_on_uptime = val >> 32;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x08,
+				     OCXL_LITTLE_ENDIAN, &args.host_load_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x10,
+				     OCXL_LITTLE_ENDIAN, &args.host_store_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x18,
+				     OCXL_LITTLE_ENDIAN, &args.media_read_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x20,
+				     OCXL_LITTLE_ENDIAN, &args.media_write_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x28,
+				     OCXL_LITTLE_ENDIAN, &args.cache_hit_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x30,
+				     OCXL_LITTLE_ENDIAN, &args.cache_miss_count);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x38,
+				     OCXL_LITTLE_ENDIAN, &args.media_read_latency);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x40,
+				     OCXL_LITTLE_ENDIAN, &args.media_write_latency);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x48,
+				     OCXL_LITTLE_ENDIAN, &args.cache_read_latency);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+				     scm_data->admin_command.data_offset + 0x08 + 0x40 + 0x50,
+				     OCXL_LITTLE_ENDIAN, &args.cache_write_latency);
+	if (rc)
+		goto out;
+
+	if (copy_to_user(uarg, &args, sizeof(args))) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	rc = scm_admin_response_handled(scm_data);
+	if (rc)
+		goto out;
+
+	rc = 0;
+	goto out;
+
+out:
+	mutex_unlock(&scm_data->admin_command.lock);
+	return rc;
+}
+
+static int scm_ioctl_eventfd(struct scm_data *scm_data,
+			     struct scm_ioctl_eventfd __user *uarg)
+{
+	struct scm_ioctl_eventfd args;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	if (scm_data->ev_ctx)
+		return -EFAULT;
+
+	scm_data->ev_ctx = eventfd_ctx_fdget(args.eventfd);
+	if (!scm_data->ev_ctx)
+		return -EFAULT;
+
+	return 0;
+}
+
+static int scm_ioctl_event_check(struct scm_data *scm_data, u64 __user *uarg)
+{
+	u64 val = 0;
+	int rc;
+	u64 chi = 0;
+
+	rc = scm_chi(scm_data, &chi);
+	if (rc < 0)
+		return -EFAULT;
+
+	if (chi & GLOBAL_MMIO_CHI_ELA)
+		val |= SCM_IOCTL_EVENT_ERROR_LOG_AVAILABLE;
+
+	if (chi & GLOBAL_MMIO_CHI_CDA)
+		val |= SCM_IOCTL_EVENT_CONTROLLER_DUMP_AVAILABLE;
+
+	if (chi & GLOBAL_MMIO_CHI_CFFS)
+		val |= SCM_IOCTL_EVENT_FIRMWARE_FATAL;
+
+	if (chi & GLOBAL_MMIO_CHI_CHFS)
+		val |= SCM_IOCTL_EVENT_HARDWARE_FATAL;
+
+	rc = copy_to_user((u64 __user *) uarg, &val, sizeof(val));
+
+	return rc;
+}
+
+/**
+ * scm_req_controller_health_perf() - Request controller health & performance data
+ * @scm_data: the SCM metadata
+ * Return: 0 on success, negative on failure
+ */
+int scm_req_controller_health_perf(struct scm_data *scm_data)
+{
+	return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+				      OCXL_LITTLE_ENDIAN,
+				      GLOBAL_MMIO_HCI_REQ_HEALTH_PERF);
+}
+
+#ifdef CONFIG_OCXL_SCM_DEBUG
+/**
+ * scm_enable_fwdebug() - Enable FW debug on the controller
+ * @scm_data: a pointer to the SCM device data
+ * Return: 0 on success, negative on failure
+ */
+static int scm_enable_fwdebug(const struct scm_data *scm_data)
+{
+	return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+				      OCXL_LITTLE_ENDIAN,
+				      GLOBAL_MMIO_HCI_FW_DEBUG);
+}
+
+/**
+ * scm_disable_fwdebug() - Disable FW debug on the controller
+ * @scm_data: a pointer to the SCM device data
+ * Return: 0 on success, negative on failure
+ */
+static int scm_disable_fwdebug(const struct scm_data *scm_data)
+{
+	return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCIC,
+				      OCXL_LITTLE_ENDIAN,
+				      GLOBAL_MMIO_HCI_FW_DEBUG);
+}
+
+static int scm_ioctl_fwdebug(struct scm_data *scm_data,
+			     struct scm_ioctl_fwdebug __user *uarg)
+{
+	struct scm_ioctl_fwdebug args;
+	u64 val;
+	int i;
+	int rc;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	// Buffer size must be a multiple of 8
+	if ((args.buf_size & 0x07))
+		return -EINVAL;
+
+	if (args.buf_size > scm_data->admin_command.data_size)
+		return -EINVAL;
+
+	mutex_lock(&scm_data->admin_command.lock);
+
+	rc = scm_enable_fwdebug(scm_data);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_FW_DEBUG);
+	if (rc)
+		goto out;
+
+	// Write DebugAction & FunctionCode
+	val = ((u64)args.debug_action << 56) | ((u64)args.function_code << 40);
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+				      scm_data->admin_command.request_offset + 0x08,
+				      OCXL_LITTLE_ENDIAN, val);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+				      scm_data->admin_command.request_offset + 0x10,
+				      OCXL_LITTLE_ENDIAN, args.debug_parameter_1);
+	if (rc)
+		goto out;
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+				      scm_data->admin_command.request_offset + 0x18,
+				      OCXL_LITTLE_ENDIAN, args.debug_parameter_2);
+	if (rc)
+		goto out;
+
+	for (i = 0x20; i < 0x38; i += 0x08)
+		rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+					      scm_data->admin_command.request_offset + i,
+					      OCXL_LITTLE_ENDIAN, 0);
+	if (rc)
+		goto out;
+
+
+	// Populate admin command buffer
+	if (args.buf_size) {
+		for (i = 0; i < args.buf_size; i += sizeof(u64)) {
+			u64 val;
+
+			if (copy_from_user(&val, &args.buf[i], sizeof(u64)))
+				return -EFAULT;
+
+			rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+						      scm_data->admin_command.data_offset + i,
+						      OCXL_HOST_ENDIAN, val);
+			if (rc)
+				goto out;
+		}
+	}
+
+	rc = scm_admin_command_execute(scm_data);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_complete_timeout(scm_data,
+						scm_data->timeouts[ADMIN_COMMAND_FW_DEBUG]);
+	if (rc < 0)
+		goto out;
+
+	rc = scm_admin_response(scm_data);
+	if (rc < 0)
+		goto out;
+	if (rc != STATUS_SUCCESS) {
+		scm_warn_status(scm_data, "Unexpected status from FW Debug", rc);
+		goto out;
+	}
+
+	if (args.buf_size) {
+		for (i = 0; i < args.buf_size; i += sizeof(u64)) {
+			u64 val;
+
+			rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+						     scm_data->admin_command.data_offset + i,
+						     OCXL_HOST_ENDIAN, &val);
+			if (rc)
+				goto out;
+
+			if (copy_to_user(&args.buf[i], &val, sizeof(u64))) {
+				rc = -EFAULT;
+				goto out;
+			}
+		}
+	}
+
+	rc = scm_admin_response_handled(scm_data);
+	if (rc)
+		goto out;
+
+	rc = scm_disable_fwdebug(scm_data);
+	if (rc)
+		goto out;
+
+out:
+	mutex_unlock(&scm_data->admin_command.lock);
+	return rc;
+}
+
+static int scm_ioctl_shutdown(struct scm_data *scm_data)
+{
+	int rc;
+
+	mutex_lock(&scm_data->admin_command.lock);
+
+	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_SHUTDOWN);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_execute(scm_data);
+	if (rc)
+		goto out;
+
+	rc = scm_admin_command_complete_timeout(scm_data, ADMIN_COMMAND_SHUTDOWN);
+	if (rc < 0) {
+		dev_warn(&scm_data->dev, "Shutdown timed out\n");
+		goto out;
+	}
+
+	rc = 0;
+	goto out;
+
+out:
+	mutex_unlock(&scm_data->admin_command.lock);
+	return rc;
+}
+
+static int scm_ioctl_mmio_write(struct scm_data *scm_data,
+				struct scm_ioctl_mmio __user *uarg)
+{
+	struct scm_ioctl_mmio args;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	return ocxl_global_mmio_write64(scm_data->ocxl_afu, args.address,
+					OCXL_LITTLE_ENDIAN, args.val);
+}
+
+static int scm_ioctl_mmio_read(struct scm_data *scm_data,
+			       struct scm_ioctl_mmio __user *uarg)
+{
+	struct scm_ioctl_mmio args;
+	int rc;
+
+	if (copy_from_user(&args, uarg, sizeof(args)))
+		return -EFAULT;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, args.address,
+				     OCXL_LITTLE_ENDIAN, &args.val);
+	if (rc)
+		return rc;
+
+	if (copy_to_user(uarg, &args, sizeof(args)))
+		return -EFAULT;
+
+	return 0;
+}
+#else
+static int scm_ioctl_fwdebug(struct scm_data *scm_data,
+			     struct scm_ioctl_fwdebug __user *uarg)
+{
+	return -EPERM;
+}
+
+static int scm_ioctl_shutdown(struct scm_data *scm_data)
+{
+	return -EPERM;
+}
+
+static int scm_ioctl_mmio_write(struct scm_data *scm_data,
+				struct scm_ioctl_mmio __user *uarg)
+{
+	return -EPERM;
+}
+
+static int scm_ioctl_mmio_read(struct scm_data *scm_data,
+			       struct scm_ioctl_mmio __user *uarg)
+{
+	return -EPERM;
+}
+#endif
+
+static long scm_file_ioctl(struct file *file, unsigned int cmd,
+			   unsigned long args)
+{
+	struct scm_data *scm_data = file->private_data;
+	int rc = -EINVAL;
+
+	switch (cmd) {
+	case SCM_IOCTL_BUFFER_INFO:
+		rc = scm_ioctl_buffer_info(scm_data,
+					   (struct scm_ioctl_buffer_info __user *)args);
+		break;
+
+	case SCM_IOCTL_ERROR_LOG:
+		rc = scm_ioctl_error_log(scm_data,
+					 (struct scm_ioctl_error_log __user *)args);
+		break;
+
+	case SCM_IOCTL_CONTROLLER_DUMP:
+		rc = scm_request_controller_dump(scm_data);
+		break;
+
+	case SCM_IOCTL_CONTROLLER_DUMP_DATA:
+		rc = scm_ioctl_controller_dump_data(scm_data,
+						    (struct scm_ioctl_controller_dump_data __user *)args);
+		break;
+
+	case SCM_IOCTL_CONTROLLER_DUMP_COMPLETE:
+		rc = scm_ioctl_controller_dump_complete(scm_data);
+		break;
+
+	case SCM_IOCTL_CONTROLLER_STATS:
+		rc = scm_ioctl_controller_stats(scm_data,
+						(struct scm_ioctl_controller_stats __user *)args);
+		break;
+
+	case SCM_IOCTL_EVENTFD:
+		rc = scm_ioctl_eventfd(scm_data,
+				       (struct scm_ioctl_eventfd __user *)args);
+		break;
+
+	case SCM_IOCTL_EVENT_CHECK:
+		rc = scm_ioctl_event_check(scm_data, (u64 __user *)args);
+		break;
+
+	case SCM_IOCTL_REQUEST_HEALTH:
+		rc = scm_req_controller_health_perf(scm_data);
+		break;
+
+	case SCM_IOCTL_FWDEBUG:
+		rc = scm_ioctl_fwdebug(scm_data,
+				       (struct scm_ioctl_fwdebug __user *)args);
+		break;
+
+	case SCM_IOCTL_SHUTDOWN:
+		rc = scm_ioctl_shutdown(scm_data);
+		break;
+
+	case SCM_IOCTL_MMIO_WRITE:
+		rc = scm_ioctl_mmio_write(scm_data,
+					  (struct scm_ioctl_mmio __user *)args);
+		break;
+
+	case SCM_IOCTL_MMIO_READ:
+		rc = scm_ioctl_mmio_read(scm_data,
+					 (struct scm_ioctl_mmio __user *)args);
+		break;
+
+	}
+
+	return rc;
+}
+
+static const struct file_operations scm_fops = {
+	.owner		= THIS_MODULE,
+	.open	   = scm_file_open,
+	.release	= scm_file_release,
+	.unlocked_ioctl = scm_file_ioctl,
+	.compat_ioctl   = scm_file_ioctl,
+};
+
+/**
+ * scm_create_cdev() - Create the chardev in /dev for this scm device
+ * @scm_data: the SCM metadata
+ * Return: 0 on success, negative on failure
+ */
+static int scm_create_cdev(struct scm_data *scm_data)
+{
+	int rc;
+
+	cdev_init(&scm_data->cdev, &scm_fops);
+	rc = cdev_add(&scm_data->cdev, scm_data->dev.devt, 1);
+	if (rc) {
+		dev_err(&scm_data->dev, "Unable to add afu char device: %d\n", rc);
+		return rc;
+	}
+	return 0;
+}
+
+/**
+ * scm_remove() - Free an OpenCAPI Storage Class Memory device
+ * @pdev: the PCI device information struct
+ */
+static void scm_remove(struct pci_dev *pdev)
+{
+	if (PCI_FUNC(pdev->devfn) == 0) {
+		struct scm_function_0 *scm_func_0 = pci_get_drvdata(pdev);
+
+		if (scm_func_0) {
+			ocxl_function_close(scm_func_0->ocxl_fn);
+			scm_func_0->ocxl_fn = NULL;
+		}
+	} else {
+		struct scm_data *scm_data = pci_get_drvdata(pdev);
+
+		if (scm_data) {
+			if (scm_data->nvdimm_bus)
+				nvdimm_bus_unregister(scm_data->nvdimm_bus);
+
+			device_unregister(&scm_data->dev);
+		}
+	}
+}
+
+/**
+ * scm_setup_device_metadata() - Retrieve config information from the AFU and save it for future use
+ * @scm_data: the SCM metadata
+ * Return: 0 on success, negative on failure
+ */
+static int scm_setup_device_metadata(struct scm_data *scm_data)
+{
+	u64 val;
+	int rc;
+	int i;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, GLOBAL_MMIO_CCAP0,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	scm_data->scm_revision = val & 0xFFFF;
+	scm_data->read_latency = (val >> 32) & 0xFF;
+	scm_data->readiness_timeout = val >> 48;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, GLOBAL_MMIO_CCAP1,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	scm_data->max_controller_dump_size = val & 0xFFFFFFFF;
+
+	rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, GLOBAL_MMIO_FWVER,
+				     OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < 8; i++)
+		scm_data->fw_version[i] = (val >> (i * 8)) & 0xff;
+
+	scm_data->fw_version[8] = '\0';
+
+	dev_info(&scm_data->dev,
+		 "Firmware version '%s' SCM revision %d:%d\n", scm_data->fw_version,
+		 scm_data->scm_revision >> 4, scm_data->scm_revision & 0x0F);
+
+	return 0;
+}
+
+static const char *scm_decode_error_log_type(u8 error_log_type)
+{
+	switch (error_log_type) {
+	case 0x00:
+		return "general";
+	case 0x01:
+		return "predictive failure";
+	case 0x02:
+		return "thermal warning";
+	case 0x03:
+		return "data loss";
+	case 0x04:
+		return "health & performance";
+	default:
+		return "unknown";
+	}
+}
+
+static void scm_dump_error_log(struct scm_data *scm_data)
+{
+	struct scm_ioctl_error_log log;
+	u32 buf_size;
+	u8 *buf;
+	int rc;
+
+	if (scm_data->admin_command.data_size == 0)
+		return;
+
+	buf_size = scm_data->admin_command.data_size - 0x48;
+	buf = kzalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	log.buf = buf;
+	log.buf_size = buf_size;
+
+	rc = scm_read_error_log(scm_data, &log, false);
+	if (rc < 0)
+		goto out;
+
+	dev_warn(&scm_data->dev,
+		 "SCM Error log: WWID=0x%016llx%016llx LID=0x%x PRC=%x type=0x%x %s, Uptime=%u seconds timestamp=0x%llx\n",
+		 log.wwid[0], log.wwid[1],
+		 log.log_identifier, log.program_reference_code,
+		 log.error_log_type,
+		 scm_decode_error_log_type(log.error_log_type),
+		 log.power_on_seconds, log.timestamp);
+	print_hex_dump(KERN_WARNING, "buf", DUMP_PREFIX_OFFSET, 16, 1, buf,
+		       log.buf_size, false);
+
+out:
+	kfree(buf);
+}
+
+static void scm_handle_nscra_doorbell(struct scm_data *scm_data)
+{
+	int rc;
+
+	if (scm_data->ns_command.op_code == NS_COMMAND_SECURE_ERASE) {
+		u64 success, attempted;
+
+
+		rc = scm_ns_response(scm_data);
+		if (rc < 0) {
+			scm_data->overwrite_state = SCM_OVERWRITE_FAILED;
+			mutex_unlock(&scm_data->ns_command.lock);
+			return;
+		}
+		if (rc != STATUS_SUCCESS)
+			scm_warn_status(scm_data, "Unexpected status from overwrite", rc);
+
+		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+					     scm_data->ns_command.response_offset +
+					     NS_RESPONSE_SECURE_ERASE_ACCESSIBLE_SUCCESS,
+					     OCXL_HOST_ENDIAN, &success);
+		if (rc) {
+			scm_data->overwrite_state = SCM_OVERWRITE_FAILED;
+			mutex_unlock(&scm_data->ns_command.lock);
+			return;
+		}
+
+		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+					     scm_data->ns_command.response_offset +
+					     NS_RESPONSE_SECURE_ERASE_ACCESSIBLE_ATTEMPTED,
+					     OCXL_HOST_ENDIAN, &attempted);
+		if (rc) {
+			scm_data->overwrite_state = SCM_OVERWRITE_FAILED;
+			mutex_unlock(&scm_data->ns_command.lock);
+			return;
+		}
+
+		scm_data->overwrite_state = SCM_OVERWRITE_SUCCESS;
+		if (success != attempted)
+			scm_data->overwrite_state = SCM_OVERWRITE_FAILED;
+
+		dev_info(&scm_data->dev,
+			 "Overwritten %llu/%llu accessible pages", success, attempted);
+
+		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+					     scm_data->ns_command.response_offset +
+					     NS_RESPONSE_SECURE_ERASE_DEFECTIVE_SUCCESS,
+					     OCXL_HOST_ENDIAN, &success);
+		if (rc) {
+			scm_data->overwrite_state = SCM_OVERWRITE_FAILED;
+			mutex_unlock(&scm_data->ns_command.lock);
+			return;
+		}
+
+		rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+					     scm_data->ns_command.response_offset +
+					     NS_RESPONSE_SECURE_ERASE_DEFECTIVE_ATTEMPTED,
+					     OCXL_HOST_ENDIAN, &attempted);
+		if (rc) {
+			scm_data->overwrite_state = SCM_OVERWRITE_FAILED;
+			mutex_unlock(&scm_data->ns_command.lock);
+			return;
+		}
+
+		if (success != attempted)
+			scm_data->overwrite_state = SCM_OVERWRITE_FAILED;
+
+		dev_info(&scm_data->dev,
+			 "Overwritten %llu/%llu defective pages", success, attempted);
+
+		scm_ns_response_handled(scm_data);
+
+		mutex_unlock(&scm_data->ns_command.lock);
+		return;
+	}
+}
+
+static irqreturn_t scm_imn0_handler(void *private)
+{
+	struct scm_data *scm_data = private;
+	int rc;
+	u64 chi = 0;
+
+	rc = scm_chi(scm_data, &chi);
+	if (rc < 0)
+		return IRQ_NONE;
+
+	if (chi & GLOBAL_MMIO_CHI_NSCRA)
+		scm_handle_nscra_doorbell(scm_data);
+
+	if (chi & GLOBAL_MMIO_CHI_ELA) {
+		dev_warn(&scm_data->dev, "Error log is available\n");
+
+		if (scm_data->ev_ctx)
+			eventfd_signal(scm_data->ev_ctx, 1);
+	}
+
+	if (chi & GLOBAL_MMIO_CHI_CDA) {
+		dev_warn(&scm_data->dev, "Controller dump is available\n");
+
+		if (scm_data->ev_ctx)
+			eventfd_signal(scm_data->ev_ctx, 1);
+	}
+
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t scm_imn1_handler(void *private)
+{
+	struct scm_data *scm_data = private;
+	u64 chi = 0;
+
+	(void)scm_chi(scm_data, &chi);
+
+	if (chi & (GLOBAL_MMIO_CHI_CFFS | GLOBAL_MMIO_CHI_CHFS)) {
+		dev_err(&scm_data->dev,
+			"Controller status is fatal, chi=0x%llx, going offline\n", chi);
+
+		if (scm_data->nvdimm_bus) {
+			nvdimm_bus_unregister(scm_data->nvdimm_bus);
+			scm_data->nvdimm_bus = NULL;
+		}
+
+		if (scm_data->ev_ctx)
+			eventfd_signal(scm_data->ev_ctx, 1);
+	}
+
+	return IRQ_HANDLED;
+}
+
+
+/**
+ * scm_setup_irq() - Set up the IRQs for the SCM device
+ * @scm_data: the SCM metadata
+ * Return: 0 on success, negative on failure
+ */
+static int scm_setup_irq(struct scm_data *scm_data)
+{
+	int rc;
+	u64 irq_addr;
+
+	rc = ocxl_afu_irq_alloc(scm_data->ocxl_context, &scm_data->irq_id[0]);
+	if (rc)
+		return rc;
+
+	rc = ocxl_irq_set_handler(scm_data->ocxl_context, scm_data->irq_id[0],
+				  scm_imn0_handler, NULL, scm_data);
+
+	irq_addr = ocxl_afu_irq_get_addr(scm_data->ocxl_context, scm_data->irq_id[0]);
+	if (!irq_addr)
+		return -EFAULT;
+
+	scm_data->irq_addr[0] = ioremap(irq_addr, PAGE_SIZE);
+	if (!scm_data->irq_addr[0])
+		return -EINVAL;
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu, GLOBAL_MMIO_IMA0_OHP,
+				      OCXL_LITTLE_ENDIAN,
+				      (u64)scm_data->irq_addr[0]);
+	if (rc)
+		goto out_irq0;
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu, GLOBAL_MMIO_IMA0_CFP,
+				      OCXL_LITTLE_ENDIAN, 0);
+	if (rc)
+		goto out_irq0;
+
+	rc = ocxl_afu_irq_alloc(scm_data->ocxl_context, &scm_data->irq_id[1]);
+	if (rc)
+		goto out_irq0;
+
+
+	rc = ocxl_irq_set_handler(scm_data->ocxl_context, scm_data->irq_id[1],
+				  scm_imn1_handler, NULL, scm_data);
+	if (rc)
+		goto out_irq0;
+
+	irq_addr = ocxl_afu_irq_get_addr(scm_data->ocxl_context, scm_data->irq_id[1]);
+	if (!irq_addr)
+		goto out_irq0;
+
+	scm_data->irq_addr[1] = ioremap(irq_addr, PAGE_SIZE);
+	if (!scm_data->irq_addr[1])
+		goto out_irq0;
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu, GLOBAL_MMIO_IMA1_OHP,
+				      OCXL_LITTLE_ENDIAN,
+				      (u64)scm_data->irq_addr[1]);
+	if (rc)
+		goto out_irq1;
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu, GLOBAL_MMIO_IMA1_CFP,
+				      OCXL_LITTLE_ENDIAN, 0);
+	if (rc)
+		goto out_irq1;
+
+	// Enable doorbells
+	rc = ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_CHIE,
+				    OCXL_LITTLE_ENDIAN,
+				    GLOBAL_MMIO_CHI_ELA | GLOBAL_MMIO_CHI_CDA |
+				    GLOBAL_MMIO_CHI_CFFS | GLOBAL_MMIO_CHI_CHFS |
+				    GLOBAL_MMIO_CHI_NSCRA);
+	if (rc)
+		goto out_irq1;
+
+	return 0;
+
+out_irq1:
+	iounmap(scm_data->irq_addr[1]);
+	scm_data->irq_addr[1] = NULL;
+
+out_irq0:
+	iounmap(scm_data->irq_addr[0]);
+	scm_data->irq_addr[0] = NULL;
+
+	return rc;
+}
+
+/**
+ * scm_probe_function_0 - Set up function 0 for an OpenCAPI Storage Class Memory device
+ * This is important as it enables higher than 0 across all other functions,
+ * which in turn enables higher bandwidth accesses
+ * @pdev: the PCI device information struct
+ * Return: 0 on success, negative on failure
+ */
+static int scm_probe_function_0(struct pci_dev *pdev)
+{
+	struct scm_function_0 *scm_func_0 = NULL;
+
+	scm_func_0 = kzalloc(sizeof(*scm_func_0), GFP_KERNEL);
+	if (!scm_func_0)
+		return -ENOMEM;
+
+	scm_func_0->pdev = pdev;
+	scm_func_0->ocxl_fn = ocxl_function_open(pdev);
+	if (IS_ERR(scm_func_0->ocxl_fn)) {
+		kfree(scm_func_0);
+		dev_err(&pdev->dev, "failed to open OCXL function\n");
+		return -EFAULT;
+	}
+
+	pci_set_drvdata(pdev, scm_func_0);
+
+	return 0;
+}
+
+/**
+ * scm_probe - Init an OpenCAPI Storage Class Memory device
+ * @pdev: the PCI device information struct
+ * @ent: The entry from scm_pci_tbl
+ * Return: 0 on success, negative on failure
+ */
+static int scm_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	struct scm_data *scm_data = NULL;
+	int elapsed;
+	u64 chi;
+
+	if (PCI_FUNC(pdev->devfn) == 0)
+		return scm_probe_function_0(pdev);
+	else if (PCI_FUNC(pdev->devfn) != 1)
+		return 0;
+
+	scm_data = kzalloc(sizeof(*scm_data), GFP_KERNEL);
+	if (!scm_data)
+		goto err;
+	scm_data->pdev = pdev;
+	mutex_init(&scm_data->admin_command.lock);
+	mutex_init(&scm_data->ns_command.lock);
+
+
+	scm_data->timeouts[ADMIN_COMMAND_ERRLOG] = 2000; // ms
+	scm_data->timeouts[ADMIN_COMMAND_HEARTBEAT] = 100; // ms
+	scm_data->timeouts[ADMIN_COMMAND_SMART] = 100; // ms
+	scm_data->timeouts[ADMIN_COMMAND_CONTROLLER_DUMP] = 1000; // ms
+	scm_data->timeouts[ADMIN_COMMAND_CONTROLLER_STATS] = 100; // ms
+	scm_data->timeouts[ADMIN_COMMAND_SHUTDOWN] = 1000; // ms
+	scm_data->timeouts[ADMIN_COMMAND_FW_UPDATE] = 16000; // ms
+
+	pci_set_drvdata(pdev, scm_data);
+
+	scm_data->ocxl_fn = ocxl_function_open(pdev);
+	if (IS_ERR(scm_data->ocxl_fn)) {
+		kfree(scm_data);
+		scm_data = NULL;
+		pci_set_drvdata(pdev, NULL);
+		dev_err(&pdev->dev, "failed to open OCXL function\n");
+		goto err;
+	}
+
+	scm_data->ocxl_afu = ocxl_function_fetch_afu(scm_data->ocxl_fn, 0);
+	if (scm_data->ocxl_afu == NULL)
+		goto err;
+
+	ocxl_afu_get(scm_data->ocxl_afu);
+
+	if (scm_register(scm_data) < 0)
+		goto err;
+
+	if (ocxl_context_alloc(&scm_data->ocxl_context, scm_data->ocxl_afu, NULL))
+		goto err;
+
+	if (ocxl_context_attach(scm_data->ocxl_context, 0, NULL))
+		goto err;
+
+	if (scm_setup_device_metadata(scm_data))
+		goto err;
+
+	if (scm_setup_irq(scm_data))
+		goto err;
+
+	if (scm_setup_command_metadata(scm_data))
+		goto err;
+
+	if (scm_create_cdev(scm_data))
+		goto err;
+
+	if (scm_sysfs_add(scm_data))
+		goto err;
+
+	if (scm_heartbeat(scm_data))
+		goto err;
+
+	elapsed = 0;
+	while (!scm_is_usable(scm_data)) {
+		if (elapsed++ > SCM_USABLE_TIMEOUT) {
+			dev_warn(&scm_data->dev, "SCM ready timeout.\n");
+			goto err;
+		}
+
+		dev_warn(&scm_data->dev,
+			 "Waiting for SCM to become usable (%d/%d seconds)\n",
+			 elapsed, SCM_USABLE_TIMEOUT);
+		msleep(1000);
+	}
+
+	if (scm_register_lpc_mem(scm_data))
+		goto err;
+
+	return 0;
+
+err:
+	if (scm_data &&
+		    (scm_chi(scm_data, &chi) == 0) &&
+		    (chi & GLOBAL_MMIO_CHI_ELA))
+		scm_dump_error_log(scm_data);
+
+	dev_err(&pdev->dev,
+		"Error detected, will not register storage class memory\n");
+	return -ENXIO;
+}
+
+struct pci_driver scm_pci_driver = {
+	.name = "ocxl-scm",
+	.id_table = scm_pci_tbl,
+	.probe = scm_probe,
+	.remove = scm_remove,
+	.shutdown = scm_remove,
+};
+
+static int scm_file_init(void)
+{
+	int rc;
+
+	mutex_init(&minors_idr_lock);
+	idr_init(&minors_idr);
+
+	rc = alloc_chrdev_region(&scm_dev, 0, SCM_NUM_MINORS, "scm");
+	if (rc) {
+		pr_err("Unable to allocate scm major number: %d\n", rc);
+		return rc;
+	}
+
+	scm_class = class_create(THIS_MODULE, "scm");
+	if (IS_ERR(scm_class)) {
+		pr_err("Unable to create scm class\n");
+		unregister_chrdev_region(scm_dev, SCM_NUM_MINORS);
+		return PTR_ERR(scm_class);
+	}
+
+	return 0;
+}
+
+static void scm_file_exit(void)
+{
+	class_destroy(scm_class);
+	unregister_chrdev_region(scm_dev, SCM_NUM_MINORS);
+	idr_destroy(&minors_idr);
+}
+
+static int __init scm_init(void)
+{
+	int rc = 0;
+
+	rc = scm_file_init();
+	if (rc)
+		return rc;
+
+	rc = pci_register_driver(&scm_pci_driver);
+	if (rc) {
+		scm_file_exit();
+		return rc;
+	}
+
+	return 0;
+}
+
+static void scm_exit(void)
+{
+	pci_unregister_driver(&scm_pci_driver);
+	scm_file_exit();
+}
+
+module_init(scm_init);
+module_exit(scm_exit);
+
+MODULE_DESCRIPTION("Storage Class Memory");
+MODULE_LICENSE("GPL");
diff --git a/drivers/nvdimm/ocxl-scm_internal.c b/drivers/nvdimm/ocxl-scm_internal.c
new file mode 100644
index 000000000000..e7c247835817
--- /dev/null
+++ b/drivers/nvdimm/ocxl-scm_internal.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2019 IBM Corp.
+
+#include <misc/ocxl.h>
+#include <linux/delay.h>
+#include "ocxl-scm_internal.h"
+
+int scm_chi(const struct scm_data *scm_data, u64 *chi)
+{
+	u64 val;
+	int rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, GLOBAL_MMIO_CHI,
+					 OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	*chi = val;
+
+	return 0;
+}
+
+bool scm_controller_is_ready(const struct scm_data *scm_data)
+{
+	u64 val = 0;
+	int rc = scm_chi(scm_data, &val);
+
+	WARN_ON(rc < 0);
+
+	return (val & GLOBAL_MMIO_CHI_CRDY) != 0;
+}
+
+static int scm_command_request(const struct scm_data *scm_data,
+			       struct command_metadata *cmd, u8 op_code)
+{
+	u64 val = op_code;
+	int rc;
+	u8 i;
+
+	if (!scm_controller_is_ready(scm_data))
+		return -EIO;
+
+	cmd->op_code = op_code;
+	cmd->id++;
+
+	val |= ((u64)cmd->id) << 16;
+
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu, cmd->request_offset,
+				      OCXL_LITTLE_ENDIAN, val);
+	if (rc)
+		return rc;
+
+	for (i = 0x08; i <= 0x38; i += 0x08) {
+		rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+					      cmd->request_offset + i,
+					      OCXL_LITTLE_ENDIAN, 0);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
+int scm_admin_command_request(struct scm_data *scm_data, u8 op_code)
+{
+	return scm_command_request(scm_data, &scm_data->admin_command, op_code);
+}
+
+int scm_command_response(const struct scm_data *scm_data,
+			 const struct command_metadata *cmd)
+{
+	u64 val;
+	u16 id;
+	u8 status;
+	int rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+					 cmd->response_offset,
+					 OCXL_LITTLE_ENDIAN, &val);
+	if (rc)
+		return rc;
+
+	status = val & 0xff;
+	id = (val >> 16) & 0xffff;
+
+	if (id != cmd->id) {
+		dev_warn(&scm_data->dev,
+			 "Expected response for command %d, but received response for command %d instead.\n",
+			 cmd->id, id);
+	}
+
+	return status;
+}
+
+int scm_admin_response(const struct scm_data *scm_data)
+{
+	return scm_command_response(scm_data, &scm_data->admin_command);
+}
+
+
+int scm_admin_command_execute(const struct scm_data *scm_data)
+{
+	return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+				      OCXL_LITTLE_ENDIAN, GLOBAL_MMIO_HCI_ACRW);
+}
+
+static bool scm_admin_command_complete(const struct scm_data *scm_data)
+{
+	u64 val = 0;
+
+	int rc = scm_chi(scm_data, &val);
+
+	WARN_ON(rc);
+
+	return (val & GLOBAL_MMIO_CHI_ACRA) != 0;
+}
+
+int scm_admin_command_complete_timeout(const struct scm_data *scm_data,
+				       int command)
+{
+	u32 timeout = scm_data->timeouts[command];
+	timeout++;
+	timeout /= 32;
+	if (!timeout)
+		timeout = SCM_DEFAULT_TIMEOUT / 32;
+
+	while (timeout-- > 0) {
+		if (scm_admin_command_complete(scm_data))
+			return 0;
+		msleep(32);
+	}
+
+	return -EBUSY;
+}
+
+int scm_admin_response_handled(const struct scm_data *scm_data)
+{
+	return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_CHIC,
+				      OCXL_LITTLE_ENDIAN, GLOBAL_MMIO_CHI_ACRA);
+}
+
+int scm_ns_command_request(struct scm_data *scm_data, u8 op_code)
+{
+	return scm_command_request(scm_data, &scm_data->ns_command, op_code);
+}
+
+int scm_ns_response(const struct scm_data *scm_data)
+{
+	return scm_command_response(scm_data, &scm_data->ns_command);
+}
+
+int scm_ns_command_execute(const struct scm_data *scm_data)
+{
+	return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+				      OCXL_LITTLE_ENDIAN, GLOBAL_MMIO_HCI_NSCRW);
+}
+
+bool scm_ns_command_complete(const struct scm_data *scm_data)
+{
+	u64 val = 0;
+	int rc = scm_chi(scm_data, &val);
+
+	WARN_ON(rc);
+
+	return (val & GLOBAL_MMIO_CHI_NSCRA) != 0;
+}
+
+int scm_ns_response_handled(const struct scm_data *scm_data)
+{
+	return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_CHIC,
+				      OCXL_LITTLE_ENDIAN, GLOBAL_MMIO_CHI_NSCRA);
+}
+
+
+void scm_warn_status(const struct scm_data *scm_data, const char *message,
+		     u8 status)
+{
+	const char *text = "Unknown";
+
+	switch (status) {
+	case STATUS_SUCCESS:
+		text = "Success";
+		break;
+
+	case STATUS_MEM_UNAVAILABLE:
+		text = "Persistent memory unavailable";
+		break;
+
+	case STATUS_BAD_OPCODE:
+		text = "Bad opcode";
+		break;
+
+	case STATUS_BAD_REQUEST_PARM:
+		text = "Bad request parameter";
+		break;
+
+	case STATUS_BAD_DATA_PARM:
+		text = "Bad data parameter";
+		break;
+
+	case STATUS_DEBUG_BLOCKED:
+		text = "Debug action blocked";
+		break;
+
+	case STATUS_FAIL:
+		text = "Failed";
+		break;
+	}
+
+	dev_warn(&scm_data->dev, "%s: %s (%x)\n", message, text, status);
+}
+
+void scm_warn_status_fw_update(const struct scm_data *scm_data,
+			       const char *message, u8 status)
+{
+	const char *text;
+
+	switch (status) {
+	case STATUS_FW_UPDATE_BLOCKED:
+		text = "Firmware update is blocked, please try again later";
+		break;
+
+	case STATUS_FW_ARG_INVALID:
+		text = "Internal error in SCM firmware update mechanism";
+		break;
+
+	case STATUS_FW_INVALID:
+		text = "Firmware content is invalid, please verify firmware update file";
+		break;
+
+	default:
+		return scm_warn_status(scm_data, message, status);
+	}
+
+	dev_warn(&scm_data->dev, "%s: %s (%x)\n", message, text, status);
+}
diff --git a/drivers/nvdimm/ocxl-scm_internal.h b/drivers/nvdimm/ocxl-scm_internal.h
new file mode 100644
index 000000000000..c236d8092c6d
--- /dev/null
+++ b/drivers/nvdimm/ocxl-scm_internal.h
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2019 IBM Corp.
+
+#include <linux/pci.h>
+#include <linux/cdev.h>
+#include <misc/ocxl.h>
+#include <linux/libnvdimm.h>
+#include <uapi/linux/ocxl-scm.h>
+#include <linux/mm.h>
+
+#define SCM_DEFAULT_TIMEOUT 100
+
+#define GLOBAL_MMIO_CHI		0x000
+#define GLOBAL_MMIO_CHIC	0x008
+#define GLOBAL_MMIO_CHIE	0x010
+#define GLOBAL_MMIO_CHIEC	0x018
+#define GLOBAL_MMIO_HCI		0x020
+#define GLOBAL_MMIO_HCIC	0x028
+#define GLOBAL_MMIO_IMA0_OHP	0x040
+#define GLOBAL_MMIO_IMA0_CFP	0x048
+#define GLOBAL_MMIO_IMA1_OHP	0x050
+#define GLOBAL_MMIO_IMA1_CFP	0x058
+#define GLOBAL_MMIO_ACMA_CREQO	0x100
+#define GLOBAL_MMIO_ACMA_CRSPO	0x104
+#define GLOBAL_MMIO_ACMA_CDBO	0x108
+#define GLOBAL_MMIO_ACMA_CDBS	0x10c
+#define GLOBAL_MMIO_NSCMA_CREQO	0x120
+#define GLOBAL_MMIO_NSCMA_CRSPO	0x124
+#define GLOBAL_MMIO_NSCMA_CDBO	0x128
+#define GLOBAL_MMIO_NSCMA_CDBS	0x12c
+#define GLOBAL_MMIO_CSTS	0x140
+#define GLOBAL_MMIO_FWVER	0x148
+#define GLOBAL_MMIO_CCAP0	0x160
+#define GLOBAL_MMIO_CCAP1	0x168
+
+#define GLOBAL_MMIO_CHI_ACRA	BIT_ULL(0)
+#define GLOBAL_MMIO_CHI_NSCRA	BIT_ULL(1)
+#define GLOBAL_MMIO_CHI_CRDY	BIT_ULL(4)
+#define GLOBAL_MMIO_CHI_CFFS	BIT_ULL(5)
+#define GLOBAL_MMIO_CHI_MA	BIT_ULL(6)
+#define GLOBAL_MMIO_CHI_ELA	BIT_ULL(7)
+#define GLOBAL_MMIO_CHI_CDA	BIT_ULL(8)
+#define GLOBAL_MMIO_CHI_CHFS	BIT_ULL(9)
+
+#define GLOBAL_MMIO_CHI_ALL	(GLOBAL_MMIO_CHI_ACRA | \
+				 GLOBAL_MMIO_CHI_NSCRA | \
+				 GLOBAL_MMIO_CHI_CRDY | \
+				 GLOBAL_MMIO_CHI_CFFS | \
+				 GLOBAL_MMIO_CHI_MA | \
+				 GLOBAL_MMIO_CHI_ELA | \
+				 GLOBAL_MMIO_CHI_CDA | \
+				 GLOBAL_MMIO_CHI_CHFS)
+
+#define GLOBAL_MMIO_HCI_ACRW				BIT_ULL(0)
+#define GLOBAL_MMIO_HCI_NSCRW				BIT_ULL(1)
+#define GLOBAL_MMIO_HCI_AFU_RESET			BIT_ULL(2)
+#define GLOBAL_MMIO_HCI_FW_DEBUG			BIT_ULL(3)
+#define GLOBAL_MMIO_HCI_CONTROLLER_DUMP			BIT_ULL(4)
+#define GLOBAL_MMIO_HCI_CONTROLLER_DUMP_COLLECTED	BIT_ULL(5)
+#define GLOBAL_MMIO_HCI_REQ_HEALTH_PERF			BIT_ULL(6)
+
+#define ADMIN_COMMAND_HEARTBEAT		0x00u
+#define ADMIN_COMMAND_SHUTDOWN		0x01u
+#define ADMIN_COMMAND_FW_UPDATE		0x02u
+#define ADMIN_COMMAND_FW_DEBUG		0x03u
+#define ADMIN_COMMAND_ERRLOG		0x04u
+#define ADMIN_COMMAND_SMART		0x05u
+#define ADMIN_COMMAND_CONTROLLER_STATS	0x06u
+#define ADMIN_COMMAND_CONTROLLER_DUMP	0x07u
+#define ADMIN_COMMAND_CMD_CAPS		0x08u
+#define ADMIN_COMMAND_MAX		0x08u
+
+#define NS_COMMAND_SECURE_ERASE	0x20ull
+
+#define NS_RESPONSE_SECURE_ERASE_ACCESSIBLE_SUCCESS 0x20
+#define NS_RESPONSE_SECURE_ERASE_ACCESSIBLE_ATTEMPTED 0x28
+#define NS_RESPONSE_SECURE_ERASE_DEFECTIVE_SUCCESS 0x30
+#define NS_RESPONSE_SECURE_ERASE_DEFECTIVE_ATTEMPTED 0x38
+
+
+
+#define STATUS_SUCCESS		0x00
+#define STATUS_MEM_UNAVAILABLE	0x20
+#define STATUS_BAD_OPCODE	0x50
+#define STATUS_BAD_REQUEST_PARM	0x51
+#define STATUS_BAD_DATA_PARM	0x52
+#define STATUS_DEBUG_BLOCKED	0x70
+#define STATUS_FAIL		0xFF
+
+#define STATUS_FW_UPDATE_BLOCKED 0x21
+#define STATUS_FW_ARG_INVALID	0x51
+#define STATUS_FW_INVALID	0x52
+
+#define SCM_LABEL_AREA_SIZE	(1UL << PA_SECTION_SHIFT)
+
+struct command_metadata {
+	u32 request_offset;
+	u32 response_offset;
+	u32 data_offset;
+	u32 data_size;
+	struct mutex lock;
+	u16 id;
+	u8 op_code;
+};
+
+struct scm_function_0 {
+	struct pci_dev *pdev;
+	struct ocxl_fn *ocxl_fn;
+};
+
+enum overwrite_state {
+	SCM_OVERWRITE_IDLE = 0,
+	SCM_OVERWRITE_BUSY,
+	SCM_OVERWRITE_SUCCESS,
+	SCM_OVERWRITE_FAILED
+};
+
+#define SCM_SMART_ATTR_POWER_ON_HOURS	0x09
+#define SCM_SMART_ATTR_TEMPERATURE	0xC2
+#define SCM_SMART_ATTR_LIFE_REMAINING	0xCA
+
+struct scm_smart_attrib {
+	__u8 id; /* out, See defines above */
+	__u16 attribute_flags;
+	__u8 current_val;
+	__u8 threshold_val;
+	__u8 worst_val;
+	__u8 reserved;
+	__u64 raw_val;
+};
+
+struct scm_smart_attribs {
+	struct scm_smart_attrib power_on_hours;
+	struct scm_smart_attrib temperature;
+	struct scm_smart_attrib life_remaining;
+};
+
+struct scm_data {
+	struct device dev;
+	struct pci_dev *pdev;
+	struct cdev cdev;
+	struct ocxl_fn *ocxl_fn;
+#define SCM_IRQ_COUNT 2
+	int irq_id[SCM_IRQ_COUNT];
+	struct dev_pagemap irq_pgmap[SCM_IRQ_COUNT];
+	void *irq_addr[SCM_IRQ_COUNT];
+	struct nd_interleave_set nd_set;
+	struct nvdimm_bus_descriptor bus_desc;
+	struct nvdimm_bus *nvdimm_bus;
+	struct ocxl_afu *ocxl_afu;
+	struct ocxl_context *ocxl_context;
+	void *metadata_addr;
+	struct scm_global_mmio *global_mmio;
+	struct command_metadata admin_command;
+	struct command_metadata ns_command;
+	enum overwrite_state overwrite_state;
+	struct resource scm_res;
+	struct nd_region *nd_region;
+	struct eventfd_ctx *ev_ctx;
+	struct scm_smart_attribs smart;
+	char fw_version[8+1];
+	u32 timeouts[ADMIN_COMMAND_MAX+1];
+
+	u16 scm_revision; // major/minor
+	u16 readiness_timeout; /* The worst case time (in milliseconds) that the host shall
+				* wait for the controller to become operational following a reset (CHI.CRDY).
+				*/
+	u16 read_latency; /* The nominal measure of latency (in nanoseconds)
+			   * associated with an unassisted read of a memory block.
+			   * This represents the capability of the raw media technology without assistance
+			   */
+	u32 max_controller_dump_size; // bytes
+};
+
+/**
+ * Create sysfs entries for an SCM device
+ * scm_data: The SCM metadata
+ */
+int scm_sysfs_add(struct scm_data *scm_data);
+
+/**
+ * Get the value of the CHI register:
+ * scm_data: The SCM metadata
+ * chi: returns the CHI value
+ *
+ * Returns 0 on success, negative on error
+ */
+int scm_chi(const struct scm_data *scm_data, u64 *chi);
+
+/**
+ * scm_controller_is_ready - Is the controller ready?
+ * @scm_data: a pointer to the SCM device data
+ * Return true if the controller is ready
+ */
+bool scm_controller_is_ready(const struct scm_data *scm_data);
+
+/**
+ * Issue an admin command request
+ *
+ * scm_data: a pointer to the SCM device data
+ * op_code: The op-code for the command
+ *
+ * Returns an identifier for the command, or negative on error
+ */
+int scm_admin_command_request(struct scm_data *scm_data, u8 op_code);
+
+/**
+ * Validate an admin response
+ *
+ * scm_data: a pointer to the SCM device data
+ *
+ * Returns the status code of the command, or negative on error
+ */
+int scm_admin_response(const struct scm_data *scm_data);
+
+/**
+ * Notify the controller to start processing a pending admin command
+ *
+ * scm_data: a pointer to the SCM device data
+ *
+ * Returns 0 on success, negative on error
+ */
+int scm_admin_command_execute(const struct scm_data *scm_data);
+
+/**
+ * Wait for an admin command to finish executing
+ *
+ * scm_data: a pointer to the SCM device data
+ * command: the admin command to wait for completion (determines the timeout)
+ *
+ * Returns 0 on success, -EBUSY on timeout
+ */
+int scm_admin_command_complete_timeout(const struct scm_data *scm_data,
+				       int command);
+
+/**
+ * Notify the controller that the admin response has been handled
+ *
+ * scm_data: a pointer to the SCM device data
+ *
+ * Returns 0 on success, negative on failure
+ */
+int scm_admin_response_handled(const struct scm_data *scm_data);
+
+/**
+ * Issue a near storage command request
+ *
+ * scm_data: a pointer to the SCM device data
+ * op_code: The op-code for the command
+ *
+ * Returns an identifier for the command, or negative on error
+ */
+int scm_ns_command_request(struct scm_data *scm_data, u8 op_code);
+
+/**
+ * Validate a near storage response
+ *
+ * scm_data: a pointer to the SCM device data
+ *
+ * Returns the status code of the command, or negative on error
+ */
+int scm_ns_response(const struct scm_data *scm_data);
+
+/**
+ * Notify the controller to start processing a pending near storage command
+ *
+ * scm_data: a pointer to the SCM device data
+ *
+ * Returns 0 on success, negative on error
+ */
+int scm_ns_command_execute(const struct scm_data *scm_data);
+
+/**
+ * Is a near storage command executing
+ *
+ * scm_data: a pointer to the SCM device data
+ *
+ * Returns true if the previous admin command has completed
+ */
+bool scm_ns_command_complete(const struct scm_data *scm_data);
+
+/**
+ * Notify the controller that the near storage response has been handled
+ *
+ * scm_data: a pointer to the SCM device data
+ *
+ * Returns 0 on success, negative on failure
+ */
+int scm_ns_response_handled(const struct scm_data *scm_data);
+
+/**
+ * Emit a kernel warning showing a command status.
+ *
+ * scm_data: a pointer to the SCM device data
+ * message: A message to accompany the warning
+ * status: The command status
+ */
+void scm_warn_status(const struct scm_data *scm_data, const char *message,
+		     u8 status);
+
+/**
+ * Emit a kernel warning showing a command status.
+ *
+ * scm_data: a pointer to the SCM device data
+ * message: A message to accompany the warning
+ * status: The command status
+ */
+void scm_warn_status_fw_update(const struct scm_data *scm_data,
+			       const char *message, u8 status);
+
+/**
+ * Request a controller dump
+ *
+ * scm_data: a pointer to the SCM device data
+ */
+int scm_request_controller_dump(struct scm_data *scm_data);
+
+/**
+ * Request health & performance data (this will emit error logs with the information)
+ *
+ * scm_data: a pointer to the SCM device data
+ */
+int scm_req_controller_health_perf(struct scm_data *scm_data);
+
+
+/**
+ * scm_overwrite() - Overwrite all data on the card
+ * @scm_data: The SCM device data
+ * Return: 0 on success
+ */
+int scm_overwrite(struct scm_data *scm_data);
diff --git a/drivers/nvdimm/ocxl-scm_sysfs.c b/drivers/nvdimm/ocxl-scm_sysfs.c
new file mode 100644
index 000000000000..080bbdeb0e56
--- /dev/null
+++ b/drivers/nvdimm/ocxl-scm_sysfs.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2018 IBM Corp.
+
+#include <linux/sysfs.h>
+#include <linux/capability.h>
+#include <linux/limits.h>
+#include <linux/firmware.h>
+#include "ocxl-scm_internal.h"
+
+static ssize_t admin_command_buffer_size_show(struct device *device,
+	struct device_attribute *attr,
+	char *buf)
+{
+	struct scm_data *scm_data = container_of(device, struct scm_data, dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", scm_data->admin_command.data_size);
+}
+
+static ssize_t fw_version_show(struct device *device,
+			       struct device_attribute *attr, char *buf)
+{
+	struct scm_data *scm_data = container_of(device, struct scm_data, dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", scm_data->fw_version);
+}
+
+#define SCM_FWUPDATE_BLOCK_SIZE	32768
+
+/**
+ * scm_update_firmware() - Write a 32kB block of data to firmware
+ * The block may be less than 32kB if it is the last one
+ *
+ * scm_data the SCM device metadata
+ * offset: the offset of the start of the block
+ * buf: the block data
+ * size: the size of the block
+ */
+static ssize_t scm_update_firmware(struct scm_data *scm_data, size_t offset,
+				   const char *buf, size_t size)
+{
+	int rc;
+	size_t i;
+	u64 val;
+
+	if (size > SCM_FWUPDATE_BLOCK_SIZE)
+		return -EINVAL;
+
+	rc = scm_admin_command_request(scm_data, ADMIN_COMMAND_FW_UPDATE);
+	if (rc)
+		return rc;
+
+	val = (((u64)offset) << 32) | size;
+	rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+				      scm_data->admin_command.request_offset + 8,
+				      OCXL_LITTLE_ENDIAN, val);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < size; i += 8) {
+		val = *(u64 *)(buf + i);
+		rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+					      scm_data->admin_command.data_offset + i,
+					      OCXL_HOST_ENDIAN, val);
+		if (rc)
+			return rc;
+	}
+
+	rc = scm_admin_command_execute(scm_data);
+	if (rc)
+		return rc;
+
+	rc = scm_admin_command_complete_timeout(scm_data,
+						ADMIN_COMMAND_FW_UPDATE);
+	if (rc < 0) {
+		dev_err(&scm_data->dev, "Firmware update timeout\n");
+		return rc;
+	}
+
+	rc = scm_admin_response(scm_data);
+	if (rc < 0)
+		return rc;
+	if (rc != STATUS_SUCCESS) {
+		scm_warn_status_fw_update(scm_data, "FW Update", rc);
+		return rc;
+	}
+
+	return 0;
+}
+
+/*
+ * Parse out a firmware filename from sysfs, retrieve it's contents and write it
+ * to the SCM device firmware storage
+ */
+static ssize_t fw_update_filename_store(struct device *device,
+					struct device_attribute *attr,
+					const char *buf, size_t size)
+{
+	char path[NAME_MAX+1];
+	const char *end;
+	const struct firmware *firmware = NULL;
+	size_t offset;
+	int rc;
+	struct scm_data *scm_data = container_of(device, struct scm_data, dev);
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	end = strnchr(buf, size, '\n');
+	if (end == NULL)
+		end = buf + strnlen(buf, size);
+
+	if ((end - buf) > NAME_MAX) {
+		dev_err(device, "Firmware filename '%-.*s' too long\n",
+			(int)(end - buf), buf);
+		return -EIO;
+	}
+
+	memcpy(path, buf, end - buf);
+	path[end - buf] = '\0';
+
+	if (request_firmware(&firmware, path, device)) {
+		dev_err(device, "Firmware file %s not found\n", path);
+		return -EIO;
+	}
+
+	if (firmware->size % 8) {
+		release_firmware(firmware);
+		dev_err(device, "Firmware '%s' should be a multiple of 8 bytes", path);
+		return -EINVAL;
+	}
+
+	mutex_lock(&scm_data->admin_command.lock);
+
+	for (offset = 0; offset < firmware->size; offset += SCM_FWUPDATE_BLOCK_SIZE) {
+		size_t remainder = firmware->size - offset;
+		size_t block_size;
+
+		block_size = (remainder > SCM_FWUPDATE_BLOCK_SIZE) ?
+			      SCM_FWUPDATE_BLOCK_SIZE : remainder;
+		rc = scm_update_firmware(scm_data, offset,
+					 firmware->data + offset, block_size);
+		if (rc) {
+			mutex_unlock(&scm_data->admin_command.lock);
+			return -EFAULT;
+		}
+	}
+
+	mutex_unlock(&scm_data->admin_command.lock);
+
+	return size;
+}
+
+/*
+ * Trigger a controller dump
+ */
+static ssize_t controller_dump_store(struct device *device,
+				     struct device_attribute *attr,
+				     const char *buf, size_t size)
+{
+	struct scm_data *scm_data = container_of(device, struct scm_data, dev);
+
+	scm_request_controller_dump(scm_data);
+
+	return size;
+}
+
+/*
+ * Request health & performance data
+ */
+static ssize_t health_request_store(struct device *device,
+				    struct device_attribute *attr,
+				    const char *buf, size_t size)
+{
+	struct scm_data *scm_data = container_of(device, struct scm_data, dev);
+
+	scm_req_controller_health_perf(scm_data);
+
+	return size;
+}
+
+/*
+ * Overwrite all media
+ */
+static ssize_t overwrite_store(struct device *device,
+			       struct device_attribute *attr,
+			       const char *buf, size_t size)
+{
+	struct scm_data *scm_data = container_of(device, struct scm_data, dev);
+
+	scm_overwrite(scm_data);
+
+	return size;
+}
+
+static struct device_attribute scm_attrs[] = {
+	__ATTR_RO(admin_command_buffer_size),
+	__ATTR_RO(fw_version),
+	__ATTR_WO(fw_update_filename),
+	__ATTR_WO(controller_dump),
+	__ATTR_WO(health_request),
+	__ATTR_WO(overwrite),
+};
+
+int scm_sysfs_add(struct scm_data *scm_data)
+{
+	int i, rc;
+
+	for (i = 0; i < ARRAY_SIZE(scm_attrs); i++) {
+		rc = device_create_file(&scm_data->dev, &scm_attrs[i]);
+		if (rc) {
+			for (; --i >= 0;)
+				device_remove_file(&scm_data->dev, &scm_attrs[i]);
+
+			return rc;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(scm_sysfs_add);
diff --git a/include/uapi/linux/ocxl-scm.h b/include/uapi/linux/ocxl-scm.h
new file mode 100644
index 000000000000..6dc7e5196da2
--- /dev/null
+++ b/include/uapi/linux/ocxl-scm.h
@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/* Copyright 2017 IBM Corp. */
+#ifndef _UAPI_OCXL_SCM_H
+#define _UAPI_OCXL_SCM_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+enum scm_fwdebug_action {
+	SCM_FWDEBUG_READ_CONTROLLER_MEMORY = 0x01,
+	SCM_FWDEBUG_WRITE_CONTROLLER_MEMORY = 0x02,
+	SCM_FWDEBUG_ENABLE_FUNCTION = 0x03,
+	SCM_FWDEBUG_DISABLE_FUNCTION = 0x04,
+	SCM_FWDEBUG_GET_PEL = 0x05, // Retrieve Persistent Error Log
+};
+
+struct scm_ioctl_buffer_info {
+	__u32	admin_command_buffer_size; // out
+	__u32	near_storage_buffer_size; // out
+};
+
+struct scm_ioctl_fwdebug { // All args are inputs
+	enum scm_fwdebug_action debug_action;
+	__u16 function_code;
+	__u16 buf_size; // Size of optional data buffer
+	__u64 debug_parameter_1;
+	__u64 debug_parameter_2;
+	__u8 *buf; // Pointer to optional in/out data buffer
+};
+
+#define SCM_ERROR_LOG_ACTION_RESET	(1 << (32-32))
+#define SCM_ERROR_LOG_ACTION_CHKFW	(1 << (53-32))
+#define SCM_ERROR_LOG_ACTION_REPLACE	(1 << (54-32))
+#define SCM_ERROR_LOG_ACTION_DUMP	(1 << (55-32))
+
+#define SCM_ERROR_LOG_TYPE_GENERAL		(0x00)
+#define SCM_ERROR_LOG_TYPE_PREDICTIVE_FAILURE	(0x01)
+#define SCM_ERROR_LOG_TYPE_THERMAL_WARNING	(0x02)
+#define SCM_ERROR_LOG_TYPE_DATA_LOSS		(0x03)
+#define SCM_ERROR_LOG_TYPE_HEALTH_PERFORMANCE	(0x04)
+
+struct scm_ioctl_error_log {
+	__u32 log_identifier; // out
+	__u32 program_reference_code; // out
+	__u32 action_flags; //out, recommended course of action
+	__u32 power_on_seconds; // out, Number of seconds the controller has been on when the error occurred
+	__u64 timestamp; // out, relative time since the current IPL
+	__u64 wwid[2]; // out, the NAA formatted WWID associated with the controller
+	char  fw_revision[8+1]; // out, firmware revision as null terminated text
+	__u16 buf_size; /* in/out, buffer size provided/required.
+			 * If required is greater than provided, the buffer
+			 * will be truncated to the amount provided. If its
+			 * less, then only the required bytes will be populated.
+			 * If it is 0, then there are no more error log entries.
+			 */
+	__u8  error_log_type;
+	__u8  reserved1;
+	__u32 reserved2;
+	__u64 reserved3[2];
+	__u8 *buf; // pointer to output buffer
+};
+
+struct scm_ioctl_controller_dump_data {
+	__u8 *buf; // pointer to output buffer
+	__u16 buf_size; /* in/out, buffer size provided/required.
+			 * If required is greater than provided, the buffer
+			 * will be truncated to the amount provided. If its
+			 * less, then only the required bytes will be populated.
+			 * If it is 0, then there is no more dump data available.
+			 */
+	__u32 offset; // in, Offset within the dump
+	__u64 reserved[8];
+};
+
+struct scm_ioctl_controller_stats {
+	__u32 reset_count;
+	__u32 reset_uptime; // seconds
+	__u32 power_on_uptime; // seconds
+	__u64 host_load_count;
+	__u64 host_store_count;
+	__u64 media_read_count;
+	__u64 media_write_count;
+	__u64 cache_hit_count;
+	__u64 cache_miss_count;
+	__u64 media_read_latency; // nanoseconds
+	__u64 media_write_latency; // nanoseconds
+	__u64 cache_read_latency; // nanoseconds
+	__u64 cache_write_latency; // nanoseconds
+};
+
+struct scm_ioctl_mmio {
+	__u64 address; // Offset in global MMIO space
+	__u64 val; // value to write/was read
+};
+
+struct scm_ioctl_eventfd {
+	__s32 eventfd;
+	__u32 reserved;
+};
+
+#ifndef BIT_ULL
+#define BIT_ULL(nr)	(1ULL << (nr))
+#endif
+
+#define SCM_IOCTL_EVENT_CONTROLLER_DUMP_AVAILABLE	BIT_ULL(0)
+#define SCM_IOCTL_EVENT_ERROR_LOG_AVAILABLE		BIT_ULL(1)
+#define SCM_IOCTL_EVENT_HARDWARE_FATAL			BIT_ULL(2)
+#define SCM_IOCTL_EVENT_FIRMWARE_FATAL			BIT_ULL(3)
+
+/* ioctl numbers */
+#define SCM_MAGIC 0x5C
+/* SCM devices */
+#define SCM_IOCTL_BUFFER_INFO	_IOR(SCM_MAGIC, 0x00, struct scm_ioctl_buffer_info)
+#define SCM_IOCTL_ERROR_LOG	_IOWR(SCM_MAGIC, 0x01, struct scm_ioctl_error_log)
+#define SCM_IOCTL_CONTROLLER_DUMP _IO(SCM_MAGIC, 0x02)
+#define SCM_IOCTL_CONTROLLER_DUMP_DATA _IOWR(SCM_MAGIC, 0x03, struct scm_ioctl_controller_dump_data)
+#define SCM_IOCTL_CONTROLLER_DUMP_COMPLETE _IO(SCM_MAGIC, 0x04)
+#define SCM_IOCTL_CONTROLLER_STATS _IO(SCM_MAGIC, 0x05)
+#define SCM_IOCTL_EVENTFD	_IOW(SCM_MAGIC, 0x06, struct scm_ioctl_eventfd)
+#define SCM_IOCTL_EVENT_CHECK	_IOR(SCM_MAGIC, 0x07, __u64)
+#define SCM_IOCTL_REQUEST_HEALTH _IO(SCM_MAGIC, 0x08)
+
+#define SCM_IOCTL_FWDEBUG	_IOWR(SCM_MAGIC, 0xf0, struct scm_ioctl_fwdebug)
+#define SCM_IOCTL_MMIO_WRITE	_IOW(SCM_MAGIC, 0xf1, struct scm_ioctl_mmio)
+#define SCM_IOCTL_MMIO_READ	_IOWR(SCM_MAGIC, 0xf2, struct scm_ioctl_mmio)
+#define SCM_IOCTL_SHUTDOWN	_IO(SCM_MAGIC, 0xf3)
+
+#endif /* _UAPI_OCXL_SCM_H */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b39827dbd071..376500f4e3a2 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -279,7 +279,7 @@ static int check_pfn_span(unsigned long pfn, unsigned long nr_pages,
 }
 
 int check_hotplug_memory_addressable(unsigned long pfn,
-					    unsigned long nr_pages)
+				     unsigned long nr_pages)
 {
 	const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1;
 
-- 
2.21.0