Re: [PATCH v23 01/22] cxl: Add type2 device basic support

["Cheatham, Benjamin" <benjamin.cheatham@amd.com>]

On 2/1/2026 9:54 AM, alejandro.lucero-palau@amd.com wrote:
> From: Alejandro Lucero <alucerop@amd.com>
> 
> Differentiate CXL memory expanders (type 3) from CXL device accelerators
> (type 2) with a new function for initializing cxl_dev_state and a macro
> for helping accel drivers to embed cxl_dev_state inside a private
> struct.
> 
> Move structs to include/cxl as the size of the accel driver private
> struct embedding cxl_dev_state needs to know the size of this struct.
> 
> Use same new initialization with the type3 pci driver.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Reviewed-by: Alison Schofield <alison.schofield@intel.com>
> Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
> ---
>  drivers/cxl/core/mbox.c      |  12 +-
>  drivers/cxl/core/memdev.c    |  32 +++++
>  drivers/cxl/cxl.h            |  97 +--------------
>  drivers/cxl/cxlmem.h         |  86 +------------
>  drivers/cxl/pci.c            |  14 +--
>  include/cxl/cxl.h            | 226 +++++++++++++++++++++++++++++++++++
>  tools/testing/cxl/test/mem.c |   3 +-
>  7 files changed, 274 insertions(+), 196 deletions(-)
>  create mode 100644 include/cxl/cxl.h
> 
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index fa6dd0c94656..bee84d0101d1 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -1514,23 +1514,21 @@ int cxl_mailbox_init(struct cxl_mailbox *cxl_mbox, struct device *host)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_mailbox_init, "CXL");
>  
> -struct cxl_memdev_state *cxl_memdev_state_create(struct device *dev)
> +struct cxl_memdev_state *cxl_memdev_state_create(struct device *dev, u64 serial,
> +						 u16 dvsec)
>  {
>  	struct cxl_memdev_state *mds;
>  	int rc;
>  
> -	mds = devm_kzalloc(dev, sizeof(*mds), GFP_KERNEL);
> +	mds = devm_cxl_dev_state_create(dev, CXL_DEVTYPE_CLASSMEM, serial,
> +					dvsec, struct cxl_memdev_state, cxlds,
> +					true);
>  	if (!mds) {
>  		dev_err(dev, "No memory available\n");
>  		return ERR_PTR(-ENOMEM);
>  	}
>  
>  	mutex_init(&mds->event.log_lock);
> -	mds->cxlds.dev = dev;
> -	mds->cxlds.reg_map.host = dev;
> -	mds->cxlds.cxl_mbox.host = dev;
> -	mds->cxlds.reg_map.resource = CXL_RESOURCE_NONE;
> -	mds->cxlds.type = CXL_DEVTYPE_CLASSMEM;
>  
>  	rc = devm_cxl_register_mce_notifier(dev, &mds->mce_notifier);
>  	if (rc == -EOPNOTSUPP)
> diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> index af3d0cc65138..22d156f25305 100644
> --- a/drivers/cxl/core/memdev.c
> +++ b/drivers/cxl/core/memdev.c
> @@ -656,6 +656,38 @@ static void detach_memdev(struct work_struct *work)
>  
>  static struct lock_class_key cxl_memdev_key;
>  
> +static void cxl_dev_state_init(struct cxl_dev_state *cxlds, struct device *dev,
> +			       enum cxl_devtype type, u64 serial, u16 dvsec,
> +			       bool has_mbox)
> +{
> +	*cxlds = (struct cxl_dev_state) {
> +		.dev = dev,
> +		.type = type,
> +		.serial = serial,
> +		.cxl_dvsec = dvsec,
> +		.reg_map.host = dev,
> +		.reg_map.resource = CXL_RESOURCE_NONE,
> +	};
> +
> +	if (has_mbox)
> +		cxlds->cxl_mbox.host = dev;
> +}
> +
> +struct cxl_dev_state *_devm_cxl_dev_state_create(struct device *dev,
> +						 enum cxl_devtype type,
> +						 u64 serial, u16 dvsec,
> +						 size_t size, bool has_mbox)
> +{
> +	struct cxl_dev_state *cxlds = devm_kzalloc(dev, size, GFP_KERNEL);
> +
> +	if (!cxlds)
> +		return NULL;
> +
> +	cxl_dev_state_init(cxlds, dev, type, serial, dvsec, has_mbox);

Nit: Having a second function to do the init seems overkill here, especially since cxl_dev_state_init() isn't called outside this
function. I'd fold it into this function instead, but I'm fine with it either way (especially if you were told otherwise before).

Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
> +	return cxlds;
> +}
> +EXPORT_SYMBOL_NS_GPL(_devm_cxl_dev_state_create, "CXL");
> +
>  static struct cxl_memdev *cxl_memdev_alloc(struct cxl_dev_state *cxlds,
>  					   const struct file_operations *fops,
>  					   const struct cxl_memdev_attach *attach)
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index e1d47062e1d3..3eaa353e430b 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -12,6 +12,7 @@
>  #include <linux/node.h>
>  #include <linux/io.h>
>  #include <linux/range.h>
> +#include <cxl/cxl.h>
>  
>  extern const struct nvdimm_security_ops *cxl_security_ops;
>  
> @@ -201,97 +202,6 @@ static inline int ways_to_eiw(unsigned int ways, u8 *eiw)
>  #define   CXLDEV_MBOX_BG_CMD_COMMAND_VENDOR_MASK GENMASK_ULL(63, 48)
>  #define CXLDEV_MBOX_PAYLOAD_OFFSET 0x20
>  
> -/*
> - * Using struct_group() allows for per register-block-type helper routines,
> - * without requiring block-type agnostic code to include the prefix.
> - */
> -struct cxl_regs {
> -	/*
> -	 * Common set of CXL Component register block base pointers
> -	 * @hdm_decoder: CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure
> -	 * @ras: CXL 2.0 8.2.5.9 CXL RAS Capability Structure
> -	 */
> -	struct_group_tagged(cxl_component_regs, component,
> -		void __iomem *hdm_decoder;
> -		void __iomem *ras;
> -	);
> -	/*
> -	 * Common set of CXL Device register block base pointers
> -	 * @status: CXL 2.0 8.2.8.3 Device Status Registers
> -	 * @mbox: CXL 2.0 8.2.8.4 Mailbox Registers
> -	 * @memdev: CXL 2.0 8.2.8.5 Memory Device Registers
> -	 */
> -	struct_group_tagged(cxl_device_regs, device_regs,
> -		void __iomem *status, *mbox, *memdev;
> -	);
> -
> -	struct_group_tagged(cxl_pmu_regs, pmu_regs,
> -		void __iomem *pmu;
> -	);
> -
> -	/*
> -	 * RCH downstream port specific RAS register
> -	 * @aer: CXL 3.0 8.2.1.1 RCH Downstream Port RCRB
> -	 */
> -	struct_group_tagged(cxl_rch_regs, rch_regs,
> -		void __iomem *dport_aer;
> -	);
> -
> -	/*
> -	 * RCD upstream port specific PCIe cap register
> -	 * @pcie_cap: CXL 3.0 8.2.1.2 RCD Upstream Port RCRB
> -	 */
> -	struct_group_tagged(cxl_rcd_regs, rcd_regs,
> -		void __iomem *rcd_pcie_cap;
> -	);
> -};
> -
> -struct cxl_reg_map {
> -	bool valid;
> -	int id;
> -	unsigned long offset;
> -	unsigned long size;
> -};
> -
> -struct cxl_component_reg_map {
> -	struct cxl_reg_map hdm_decoder;
> -	struct cxl_reg_map ras;
> -};
> -
> -struct cxl_device_reg_map {
> -	struct cxl_reg_map status;
> -	struct cxl_reg_map mbox;
> -	struct cxl_reg_map memdev;
> -};
> -
> -struct cxl_pmu_reg_map {
> -	struct cxl_reg_map pmu;
> -};
> -
> -/**
> - * struct cxl_register_map - DVSEC harvested register block mapping parameters
> - * @host: device for devm operations and logging
> - * @base: virtual base of the register-block-BAR + @block_offset
> - * @resource: physical resource base of the register block
> - * @max_size: maximum mapping size to perform register search
> - * @reg_type: see enum cxl_regloc_type
> - * @component_map: cxl_reg_map for component registers
> - * @device_map: cxl_reg_maps for device registers
> - * @pmu_map: cxl_reg_maps for CXL Performance Monitoring Units
> - */
> -struct cxl_register_map {
> -	struct device *host;
> -	void __iomem *base;
> -	resource_size_t resource;
> -	resource_size_t max_size;
> -	u8 reg_type;
> -	union {
> -		struct cxl_component_reg_map component_map;
> -		struct cxl_device_reg_map device_map;
> -		struct cxl_pmu_reg_map pmu_map;
> -	};
> -};
> -
>  void cxl_probe_component_regs(struct device *dev, void __iomem *base,
>  			      struct cxl_component_reg_map *map);
>  void cxl_probe_device_regs(struct device *dev, void __iomem *base,
> @@ -497,11 +407,6 @@ struct cxl_region_params {
>  	resource_size_t cache_size;
>  };
>  
> -enum cxl_partition_mode {
> -	CXL_PARTMODE_RAM,
> -	CXL_PARTMODE_PMEM,
> -};
> -
>  /*
>   * Indicate whether this region has been assembled by autodetection or
>   * userspace assembly. Prevent endpoint decoders outside of automatic
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index ef202b34e5ea..281546de426e 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -113,8 +113,6 @@ int devm_cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
>  			 resource_size_t base, resource_size_t len,
>  			 resource_size_t skipped);
>  
> -#define CXL_NR_PARTITIONS_MAX 2
> -
>  struct cxl_dpa_info {
>  	u64 size;
>  	struct cxl_dpa_part_info {
> @@ -373,87 +371,6 @@ struct cxl_security_state {
>  	struct kernfs_node *sanitize_node;
>  };
>  
> -/*
> - * enum cxl_devtype - delineate type-2 from a generic type-3 device
> - * @CXL_DEVTYPE_DEVMEM - Vendor specific CXL Type-2 device implementing HDM-D or
> - *			 HDM-DB, no requirement that this device implements a
> - *			 mailbox, or other memory-device-standard manageability
> - *			 flows.
> - * @CXL_DEVTYPE_CLASSMEM - Common class definition of a CXL Type-3 device with
> - *			   HDM-H and class-mandatory memory device registers
> - */
> -enum cxl_devtype {
> -	CXL_DEVTYPE_DEVMEM,
> -	CXL_DEVTYPE_CLASSMEM,
> -};
> -
> -/**
> - * struct cxl_dpa_perf - DPA performance property entry
> - * @dpa_range: range for DPA address
> - * @coord: QoS performance data (i.e. latency, bandwidth)
> - * @cdat_coord: raw QoS performance data from CDAT
> - * @qos_class: QoS Class cookies
> - */
> -struct cxl_dpa_perf {
> -	struct range dpa_range;
> -	struct access_coordinate coord[ACCESS_COORDINATE_MAX];
> -	struct access_coordinate cdat_coord[ACCESS_COORDINATE_MAX];
> -	int qos_class;
> -};
> -
> -/**
> - * struct cxl_dpa_partition - DPA partition descriptor
> - * @res: shortcut to the partition in the DPA resource tree (cxlds->dpa_res)
> - * @perf: performance attributes of the partition from CDAT
> - * @mode: operation mode for the DPA capacity, e.g. ram, pmem, dynamic...
> - */
> -struct cxl_dpa_partition {
> -	struct resource res;
> -	struct cxl_dpa_perf perf;
> -	enum cxl_partition_mode mode;
> -};
> -
> -/**
> - * struct cxl_dev_state - The driver device state
> - *
> - * cxl_dev_state represents the CXL driver/device state.  It provides an
> - * interface to mailbox commands as well as some cached data about the device.
> - * Currently only memory devices are represented.
> - *
> - * @dev: The device associated with this CXL state
> - * @cxlmd: The device representing the CXL.mem capabilities of @dev
> - * @reg_map: component and ras register mapping parameters
> - * @regs: Parsed register blocks
> - * @cxl_dvsec: Offset to the PCIe device DVSEC
> - * @rcd: operating in RCD mode (CXL 3.0 9.11.8 CXL Devices Attached to an RCH)
> - * @media_ready: Indicate whether the device media is usable
> - * @dpa_res: Overall DPA resource tree for the device
> - * @part: DPA partition array
> - * @nr_partitions: Number of DPA partitions
> - * @serial: PCIe Device Serial Number
> - * @type: Generic Memory Class device or Vendor Specific Memory device
> - * @cxl_mbox: CXL mailbox context
> - * @cxlfs: CXL features context
> - */
> -struct cxl_dev_state {
> -	struct device *dev;
> -	struct cxl_memdev *cxlmd;
> -	struct cxl_register_map reg_map;
> -	struct cxl_regs regs;
> -	int cxl_dvsec;
> -	bool rcd;
> -	bool media_ready;
> -	struct resource dpa_res;
> -	struct cxl_dpa_partition part[CXL_NR_PARTITIONS_MAX];
> -	unsigned int nr_partitions;
> -	u64 serial;
> -	enum cxl_devtype type;
> -	struct cxl_mailbox cxl_mbox;
> -#ifdef CONFIG_CXL_FEATURES
> -	struct cxl_features_state *cxlfs;
> -#endif
> -};
> -
>  static inline resource_size_t cxl_pmem_size(struct cxl_dev_state *cxlds)
>  {
>  	/*
> @@ -858,7 +775,8 @@ int cxl_dev_state_identify(struct cxl_memdev_state *mds);
>  int cxl_await_media_ready(struct cxl_dev_state *cxlds);
>  int cxl_enumerate_cmds(struct cxl_memdev_state *mds);
>  int cxl_mem_dpa_fetch(struct cxl_memdev_state *mds, struct cxl_dpa_info *info);
> -struct cxl_memdev_state *cxl_memdev_state_create(struct device *dev);
> +struct cxl_memdev_state *cxl_memdev_state_create(struct device *dev, u64 serial,
> +						 u16 dvsec);
>  void set_exclusive_cxl_commands(struct cxl_memdev_state *mds,
>  				unsigned long *cmds);
>  void clear_exclusive_cxl_commands(struct cxl_memdev_state *mds,
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index 1cf232220873..24179cc702bf 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -911,25 +911,25 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  	int rc, pmu_count;
>  	unsigned int i;
>  	bool irq_avail;
> +	u16 dvsec;
>  
>  	rc = pcim_enable_device(pdev);
>  	if (rc)
>  		return rc;
>  	pci_set_master(pdev);
>  
> -	mds = cxl_memdev_state_create(&pdev->dev);
> +	dvsec = pci_find_dvsec_capability(pdev, PCI_VENDOR_ID_CXL,
> +					  PCI_DVSEC_CXL_DEVICE);
> +	if (!dvsec)
> +		pci_warn(pdev, "Device DVSEC not present, skip CXL.mem init\n");
> +
> +	mds = cxl_memdev_state_create(&pdev->dev, pci_get_dsn(pdev), dvsec);
>  	if (IS_ERR(mds))
>  		return PTR_ERR(mds);
>  	cxlds = &mds->cxlds;
>  	pci_set_drvdata(pdev, cxlds);
>  
>  	cxlds->rcd = is_cxl_restricted(pdev);
> -	cxlds->serial = pci_get_dsn(pdev);
> -	cxlds->cxl_dvsec = pci_find_dvsec_capability(
> -		pdev, PCI_VENDOR_ID_CXL, PCI_DVSEC_CXL_DEVICE);
> -	if (!cxlds->cxl_dvsec)
> -		dev_warn(&pdev->dev,
> -			 "Device DVSEC not present, skip CXL.mem init\n");
>  
>  	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
>  	if (rc)
> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
> new file mode 100644
> index 000000000000..13d448686189
> --- /dev/null
> +++ b/include/cxl/cxl.h
> @@ -0,0 +1,226 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright(c) 2020 Intel Corporation. */
> +/* Copyright(c) 2025 Advanced Micro Devices, Inc. */
> +
> +#ifndef __CXL_CXL_H__
> +#define __CXL_CXL_H__
> +
> +#include <linux/node.h>
> +#include <linux/ioport.h>
> +#include <cxl/mailbox.h>
> +
> +/**
> + * enum cxl_devtype - delineate type-2 from a generic type-3 device
> + * @CXL_DEVTYPE_DEVMEM: Vendor specific CXL Type-2 device implementing HDM-D or
> + *			 HDM-DB, no requirement that this device implements a
> + *			 mailbox, or other memory-device-standard manageability
> + *			 flows.
> + * @CXL_DEVTYPE_CLASSMEM: Common class definition of a CXL Type-3 device with
> + *			   HDM-H and class-mandatory memory device registers
> + */
> +enum cxl_devtype {
> +	CXL_DEVTYPE_DEVMEM,
> +	CXL_DEVTYPE_CLASSMEM,
> +};
> +
> +struct device;
> +
> +/*
> + * Using struct_group() allows for per register-block-type helper routines,
> + * without requiring block-type agnostic code to include the prefix.
> + */
> +struct cxl_regs {
> +	/*
> +	 * Common set of CXL Component register block base pointers
> +	 * @hdm_decoder: CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure
> +	 * @ras: CXL 2.0 8.2.5.9 CXL RAS Capability Structure
> +	 */
> +	struct_group_tagged(cxl_component_regs, component,
> +		void __iomem *hdm_decoder;
> +		void __iomem *ras;
> +	);
> +	/*
> +	 * Common set of CXL Device register block base pointers
> +	 * @status: CXL 2.0 8.2.8.3 Device Status Registers
> +	 * @mbox: CXL 2.0 8.2.8.4 Mailbox Registers
> +	 * @memdev: CXL 2.0 8.2.8.5 Memory Device Registers
> +	 */
> +	struct_group_tagged(cxl_device_regs, device_regs,
> +		void __iomem *status, *mbox, *memdev;
> +	);
> +
> +	struct_group_tagged(cxl_pmu_regs, pmu_regs,
> +		void __iomem *pmu;
> +	);
> +
> +	/*
> +	 * RCH downstream port specific RAS register
> +	 * @aer: CXL 3.0 8.2.1.1 RCH Downstream Port RCRB
> +	 */
> +	struct_group_tagged(cxl_rch_regs, rch_regs,
> +		void __iomem *dport_aer;
> +	);
> +
> +	/*
> +	 * RCD upstream port specific PCIe cap register
> +	 * @pcie_cap: CXL 3.0 8.2.1.2 RCD Upstream Port RCRB
> +	 */
> +	struct_group_tagged(cxl_rcd_regs, rcd_regs,
> +		void __iomem *rcd_pcie_cap;
> +	);
> +};
> +
> +struct cxl_reg_map {
> +	bool valid;
> +	int id;
> +	unsigned long offset;
> +	unsigned long size;
> +};
> +
> +struct cxl_component_reg_map {
> +	struct cxl_reg_map hdm_decoder;
> +	struct cxl_reg_map ras;
> +};
> +
> +struct cxl_device_reg_map {
> +	struct cxl_reg_map status;
> +	struct cxl_reg_map mbox;
> +	struct cxl_reg_map memdev;
> +};
> +
> +struct cxl_pmu_reg_map {
> +	struct cxl_reg_map pmu;
> +};
> +
> +/**
> + * struct cxl_register_map - DVSEC harvested register block mapping parameters
> + * @host: device for devm operations and logging
> + * @base: virtual base of the register-block-BAR + @block_offset
> + * @resource: physical resource base of the register block
> + * @max_size: maximum mapping size to perform register search
> + * @reg_type: see enum cxl_regloc_type
> + * @component_map: cxl_reg_map for component registers
> + * @device_map: cxl_reg_maps for device registers
> + * @pmu_map: cxl_reg_maps for CXL Performance Monitoring Units
> + */
> +struct cxl_register_map {
> +	struct device *host;
> +	void __iomem *base;
> +	resource_size_t resource;
> +	resource_size_t max_size;
> +	u8 reg_type;
> +	union {
> +		struct cxl_component_reg_map component_map;
> +		struct cxl_device_reg_map device_map;
> +		struct cxl_pmu_reg_map pmu_map;
> +	};
> +};
> +
> +/**
> + * struct cxl_dpa_perf - DPA performance property entry
> + * @dpa_range: range for DPA address
> + * @coord: QoS performance data (i.e. latency, bandwidth)
> + * @cdat_coord: raw QoS performance data from CDAT
> + * @qos_class: QoS Class cookies
> + */
> +struct cxl_dpa_perf {
> +	struct range dpa_range;
> +	struct access_coordinate coord[ACCESS_COORDINATE_MAX];
> +	struct access_coordinate cdat_coord[ACCESS_COORDINATE_MAX];
> +	int qos_class;
> +};
> +
> +enum cxl_partition_mode {
> +	CXL_PARTMODE_RAM,
> +	CXL_PARTMODE_PMEM,
> +};
> +
> +/**
> + * struct cxl_dpa_partition - DPA partition descriptor
> + * @res: shortcut to the partition in the DPA resource tree (cxlds->dpa_res)
> + * @perf: performance attributes of the partition from CDAT
> + * @mode: operation mode for the DPA capacity, e.g. ram, pmem, dynamic...
> + */
> +struct cxl_dpa_partition {
> +	struct resource res;
> +	struct cxl_dpa_perf perf;
> +	enum cxl_partition_mode mode;
> +};
> +
> +#define CXL_NR_PARTITIONS_MAX 2
> +
> +/**
> + * struct cxl_dev_state - The driver device state
> + *
> + * cxl_dev_state represents the CXL driver/device state.  It provides an
> + * interface to mailbox commands as well as some cached data about the device.
> + * Currently only memory devices are represented.
> + *
> + * @dev: The device associated with this CXL state
> + * @cxlmd: The device representing the CXL.mem capabilities of @dev
> + * @reg_map: component and ras register mapping parameters
> + * @regs: Parsed register blocks
> + * @cxl_dvsec: Offset to the PCIe device DVSEC
> + * @rcd: operating in RCD mode (CXL 3.0 9.11.8 CXL Devices Attached to an RCH)
> + * @media_ready: Indicate whether the device media is usable
> + * @dpa_res: Overall DPA resource tree for the device
> + * @part: DPA partition array
> + * @nr_partitions: Number of DPA partitions
> + * @serial: PCIe Device Serial Number
> + * @type: Generic Memory Class device or Vendor Specific Memory device
> + * @cxl_mbox: CXL mailbox context
> + * @cxlfs: CXL features context
> + */
> +struct cxl_dev_state {
> +	/* public for Type2 drivers */
> +	struct device *dev;
> +	struct cxl_memdev *cxlmd;
> +
> +	/* private for Type2 drivers */
> +	struct cxl_register_map reg_map;
> +	struct cxl_regs regs;
> +	int cxl_dvsec;
> +	bool rcd;
> +	bool media_ready;
> +	struct resource dpa_res;
> +	struct cxl_dpa_partition part[CXL_NR_PARTITIONS_MAX];
> +	unsigned int nr_partitions;
> +	u64 serial;
> +	enum cxl_devtype type;
> +	struct cxl_mailbox cxl_mbox;
> +#ifdef CONFIG_CXL_FEATURES
> +	struct cxl_features_state *cxlfs;
> +#endif
> +};
> +
> +struct cxl_dev_state *_devm_cxl_dev_state_create(struct device *dev,
> +						 enum cxl_devtype type,
> +						 u64 serial, u16 dvsec,
> +						 size_t size, bool has_mbox);
> +
> +/**
> + * cxl_dev_state_create - safely create and cast a cxl dev state embedded in a
> + * driver specific struct.
> + *
> + * @parent: device behind the request
> + * @type: CXL device type
> + * @serial: device identification
> + * @dvsec: dvsec capability offset
> + * @drv_struct: driver struct embedding a cxl_dev_state struct
> + * @member: drv_struct member as cxl_dev_state
> + * @mbox: true if mailbox supported
> + *
> + * Returns a pointer to the drv_struct allocated and embedding a cxl_dev_state
> + * struct initialized.
> + *
> + * Introduced for Type2 driver support.
> + */
> +#define devm_cxl_dev_state_create(parent, type, serial, dvsec, drv_struct, member, mbox)	\
> +	({										\
> +		static_assert(__same_type(struct cxl_dev_state,				\
> +			      ((drv_struct *)NULL)->member));				\
> +		static_assert(offsetof(drv_struct, member) == 0);			\
> +		(drv_struct *)_devm_cxl_dev_state_create(parent, type, serial, dvsec,	\
> +						      sizeof(drv_struct), mbox);	\
> +	})
> +#endif /* __CXL_CXL_H__ */
> diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> index cb87e8c0e63c..79f42f4474d4 100644
> --- a/tools/testing/cxl/test/mem.c
> +++ b/tools/testing/cxl/test/mem.c
> @@ -1716,7 +1716,7 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
>  	if (rc)
>  		return rc;
>  
> -	mds = cxl_memdev_state_create(dev);
> +	mds = cxl_memdev_state_create(dev, pdev->id + 1, 0);
>  	if (IS_ERR(mds))
>  		return PTR_ERR(mds);
>  
> @@ -1732,7 +1732,6 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
>  	mds->event.buf = (struct cxl_get_event_payload *) mdata->event_buf;
>  	INIT_DELAYED_WORK(&mds->security.poll_dwork, cxl_mockmem_sanitize_work);
>  
> -	cxlds->serial = pdev->id + 1;
>  	if (is_rcd(pdev))
>  		cxlds->rcd = true;
>