Merge branch 'for-7.1/cxl-type2-support' into cxl-for-next

Prep patches for CXL type2 accelerator basic support

cxl/region: Factor out interleave granularity setup
cxl/region: Factor out interleave ways setup
cxl: Make region type based on endpoint type
cxl/pci: Remove redundant cxl_pci_find_port() call
cxl: Move pci generic code from cxl_pci to core/cxl_pci
cxl: export internal structs for external Type2 drivers
cxl: support Type2 when initializing cxl_dev_state

12 files changed, 394 insertions, 300 deletions

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 5b0570df0fd9..5539e941782f 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -224,4 +224,6 @@ int cxl_set_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
 		    u16 *return_code);
 #endif
 
+resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
+					   struct cxl_dport *dport);
 #endif /* __CXL_CORE_H__ */
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 3f34bbabf4d3..aaa5c6277ebf 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -1522,23 +1522,21 @@ 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 591425866045..80e65690eb77 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -659,6 +659,30 @@ static void detach_memdev(struct work_struct *work)
 
 static struct lock_class_key cxl_memdev_key;
 
+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;
+
+	cxlds->dev = dev;
+	cxlds->type = type;
+	cxlds->serial = serial;
+	cxlds->cxl_dvsec = dvsec;
+	cxlds->reg_map.host = dev;
+	cxlds->reg_map.resource = CXL_RESOURCE_NONE;
+
+	if (has_mbox)
+		cxlds->cxl_mbox.host = dev;
+
+	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/core/pci.c b/drivers/cxl/core/pci.c
index f96ce884a213..d1f487b3d809 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -696,6 +696,63 @@ bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_reset_detected, "CXL");
 
+static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
+				  struct cxl_register_map *map,
+				  struct cxl_dport *dport)
+{
+	resource_size_t component_reg_phys;
+
+	*map = (struct cxl_register_map) {
+		.host = &pdev->dev,
+		.resource = CXL_RESOURCE_NONE,
+	};
+
+	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
+	if (component_reg_phys == CXL_RESOURCE_NONE)
+		return -ENXIO;
+
+	map->resource = component_reg_phys;
+	map->reg_type = CXL_REGLOC_RBI_COMPONENT;
+	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
+
+	return 0;
+}
+
+int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
+		       struct cxl_register_map *map)
+{
+	int rc;
+
+	rc = cxl_find_regblock(pdev, type, map);
+
+	/*
+	 * If the Register Locator DVSEC does not exist, check if it
+	 * is an RCH and try to extract the Component Registers from
+	 * an RCRB.
+	 */
+	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev)) {
+		struct cxl_dport *dport;
+		struct cxl_port *port __free(put_cxl_port) =
+			cxl_pci_find_port(pdev, &dport);
+		if (!port)
+			return -EPROBE_DEFER;
+
+		rc = cxl_rcrb_get_comp_regs(pdev, map, dport);
+		if (rc)
+			return rc;
+
+		rc = cxl_dport_map_rcd_linkcap(pdev, dport);
+		if (rc)
+			return rc;
+
+	} else if (rc) {
+		return rc;
+	}
+
+	return cxl_setup_regs(map);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_pci_setup_regs, "CXL");
+
 int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c)
 {
 	int speed, bw;
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index f901034624e1..8fc895c384ab 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -485,22 +485,14 @@ static ssize_t interleave_ways_show(struct device *dev,
 
 static const struct attribute_group *get_cxl_region_target_group(void);
 
-static ssize_t interleave_ways_store(struct device *dev,
-				     struct device_attribute *attr,
-				     const char *buf, size_t len)
+static int set_interleave_ways(struct cxl_region *cxlr, int val)
 {
-	struct cxl_region *cxlr = to_cxl_region(dev);
 	struct cxl_root_decoder *cxlrd = cxlr->cxlrd;
 	struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
 	struct cxl_region_params *p = &cxlr->params;
-	unsigned int val, save;
-	int rc;
+	int save, rc;
 	u8 iw;
 
-	rc = kstrtouint(buf, 0, &val);
-	if (rc)
-		return rc;
-
 	rc = ways_to_eiw(val, &iw);
 	if (rc)
 		return rc;
@@ -515,9 +507,7 @@ static ssize_t interleave_ways_store(struct device *dev,
 		return -EINVAL;
 	}
 
-	ACQUIRE(rwsem_write_kill, rwsem)(&cxl_rwsem.region);
-	if ((rc = ACQUIRE_ERR(rwsem_write_kill, &rwsem)))
-		return rc;
+	lockdep_assert_held_write(&cxl_rwsem.region);
 
 	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE)
 		return -EBUSY;
@@ -525,10 +515,31 @@ static ssize_t interleave_ways_store(struct device *dev,
 	save = p->interleave_ways;
 	p->interleave_ways = val;
 	rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group());
-	if (rc) {
+	if (rc)
 		p->interleave_ways = save;
+
+	return rc;
+}
+
+static ssize_t interleave_ways_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t len)
+{
+	struct cxl_region *cxlr = to_cxl_region(dev);
+	int val;
+	int rc;
+
+	rc = kstrtoint(buf, 0, &val);
+	if (rc)
+		return rc;
+
+	ACQUIRE(rwsem_write_kill, rwsem)(&cxl_rwsem.region);
+	if ((rc = ACQUIRE_ERR(rwsem_write_kill, &rwsem)))
+		return rc;
+
+	rc = set_interleave_ways(cxlr, val);
+	if (rc)
 		return rc;
-	}
 
 	return len;
 }
@@ -548,21 +559,14 @@ static ssize_t interleave_granularity_show(struct device *dev,
 	return sysfs_emit(buf, "%d\n", p->interleave_granularity);
 }
 
-static ssize_t interleave_granularity_store(struct device *dev,
-					    struct device_attribute *attr,
-					    const char *buf, size_t len)
+static int set_interleave_granularity(struct cxl_region *cxlr, int val)
 {
-	struct cxl_region *cxlr = to_cxl_region(dev);
 	struct cxl_root_decoder *cxlrd = cxlr->cxlrd;
 	struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
 	struct cxl_region_params *p = &cxlr->params;
-	int rc, val;
+	int rc;
 	u16 ig;
 
-	rc = kstrtoint(buf, 0, &val);
-	if (rc)
-		return rc;
-
 	rc = granularity_to_eig(val, &ig);
 	if (rc)
 		return rc;
@@ -578,14 +582,33 @@ static ssize_t interleave_granularity_store(struct device *dev,
 	if (cxld->interleave_ways > 1 && val != cxld->interleave_granularity)
 		return -EINVAL;
 
-	ACQUIRE(rwsem_write_kill, rwsem)(&cxl_rwsem.region);
-	if ((rc = ACQUIRE_ERR(rwsem_write_kill, &rwsem)))
-		return rc;
+	lockdep_assert_held_write(&cxl_rwsem.region);
 
 	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE)
 		return -EBUSY;
 
 	p->interleave_granularity = val;
+	return 0;
+}
+
+static ssize_t interleave_granularity_store(struct device *dev,
+					    struct device_attribute *attr,
+					    const char *buf, size_t len)
+{
+	struct cxl_region *cxlr = to_cxl_region(dev);
+	int rc, val;
+
+	rc = kstrtoint(buf, 0, &val);
+	if (rc)
+		return rc;
+
+	ACQUIRE(rwsem_write_kill, rwsem)(&cxl_rwsem.region);
+	if ((rc = ACQUIRE_ERR(rwsem_write_kill, &rwsem)))
+		return rc;
+
+	rc = set_interleave_granularity(cxlr, val);
+	if (rc)
+		return rc;
 
 	return len;
 }
@@ -2667,7 +2690,8 @@ static ssize_t create_ram_region_show(struct device *dev,
 }
 
 static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd,
-					  enum cxl_partition_mode mode, int id)
+					  enum cxl_partition_mode mode, int id,
+					  enum cxl_decoder_type target_type)
 {
 	int rc;
 
@@ -2689,7 +2713,7 @@ static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd,
 		return ERR_PTR(-EBUSY);
 	}
 
-	return devm_cxl_add_region(cxlrd, id, mode, CXL_DECODER_HOSTONLYMEM);
+	return devm_cxl_add_region(cxlrd, id, mode, target_type);
 }
 
 static ssize_t create_region_store(struct device *dev, const char *buf,
@@ -2703,7 +2727,7 @@ static ssize_t create_region_store(struct device *dev, const char *buf,
 	if (rc != 1)
 		return -EINVAL;
 
-	cxlr = __create_region(cxlrd, mode, id);
+	cxlr = __create_region(cxlrd, mode, id, CXL_DECODER_HOSTONLYMEM);
 	if (IS_ERR(cxlr))
 		return PTR_ERR(cxlr);
 
@@ -3921,7 +3945,8 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
 
 	do {
 		cxlr = __create_region(cxlrd, cxlds->part[part].mode,
-				       atomic_read(&cxlrd->region_id));
+				       atomic_read(&cxlrd->region_id),
+				       cxled->cxld.target_type);
 	} while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY);
 
 	if (IS_ERR(cxlr)) {
diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
index a010b3214342..93710cf4f0a6 100644
--- a/drivers/cxl/core/regs.c
+++ b/drivers/cxl/core/regs.c
@@ -641,4 +641,3 @@ resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
 		return CXL_RESOURCE_NONE;
 	return __rcrb_to_component(dev, &dport->rcrb, CXL_RCRB_UPSTREAM);
 }
-EXPORT_SYMBOL_NS_GPL(cxl_rcd_component_reg_phys, "CXL");
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index d09c84bcc015..f08be12e0e53 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,
@@ -312,8 +222,6 @@ int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
 		      struct cxl_register_map *map);
 int cxl_setup_regs(struct cxl_register_map *map);
 struct cxl_dport;
-resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
-					   struct cxl_dport *dport);
 int cxl_dport_map_rcd_linkcap(struct pci_dev *pdev, struct cxl_dport *dport);
 
 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
@@ -498,11 +406,6 @@ 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 7a34a19c02c8..02054f233fc5 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: Class device "Device" registers
- * @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_device_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/cxlpci.h b/drivers/cxl/cxlpci.h
index 0cf64218aa16..b826eb53cf7b 100644
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -74,6 +74,17 @@ static inline bool cxl_pci_flit_256(struct pci_dev *pdev)
 	return lnksta2 & PCI_EXP_LNKSTA2_FLIT;
 }
 
+/*
+ * Assume that the caller has already validated that @pdev has CXL
+ * capabilities, any RCiEP with CXL capabilities is treated as a
+ * Restricted CXL Device (RCD) and finds upstream port and endpoint
+ * registers in a Root Complex Register Block (RCRB).
+ */
+static inline bool is_cxl_restricted(struct pci_dev *pdev)
+{
+	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
+}
+
 struct cxl_dev_state;
 void read_cdat_data(struct cxl_port *port);
 
@@ -101,4 +112,6 @@ static inline void devm_cxl_port_ras_setup(struct cxl_port *port)
 }
 #endif
 
+int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
+		       struct cxl_register_map *map);
 #endif /* __CXL_PCI_H__ */
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 6e04c8ef1912..bace662dc988 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -465,76 +465,6 @@ static int cxl_pci_setup_mailbox(struct cxl_memdev_state *mds, bool irq_avail)
 	return 0;
 }
 
-/*
- * Assume that any RCIEP that emits the CXL memory expander class code
- * is an RCD
- */
-static bool is_cxl_restricted(struct pci_dev *pdev)
-{
-	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
-}
-
-static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
-				  struct cxl_register_map *map,
-				  struct cxl_dport *dport)
-{
-	resource_size_t component_reg_phys;
-
-	*map = (struct cxl_register_map) {
-		.host = &pdev->dev,
-		.resource = CXL_RESOURCE_NONE,
-	};
-
-	struct cxl_port *port __free(put_cxl_port) =
-		cxl_pci_find_port(pdev, &dport);
-	if (!port)
-		return -EPROBE_DEFER;
-
-	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
-	if (component_reg_phys == CXL_RESOURCE_NONE)
-		return -ENXIO;
-
-	map->resource = component_reg_phys;
-	map->reg_type = CXL_REGLOC_RBI_COMPONENT;
-	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
-
-	return 0;
-}
-
-static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
-			      struct cxl_register_map *map)
-{
-	int rc;
-
-	rc = cxl_find_regblock(pdev, type, map);
-
-	/*
-	 * If the Register Locator DVSEC does not exist, check if it
-	 * is an RCH and try to extract the Component Registers from
-	 * an RCRB.
-	 */
-	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev)) {
-		struct cxl_dport *dport;
-		struct cxl_port *port __free(put_cxl_port) =
-			cxl_pci_find_port(pdev, &dport);
-		if (!port)
-			return -EPROBE_DEFER;
-
-		rc = cxl_rcrb_get_comp_regs(pdev, map, dport);
-		if (rc)
-			return rc;
-
-		rc = cxl_dport_map_rcd_linkcap(pdev, dport);
-		if (rc)
-			return rc;
-
-	} else if (rc) {
-		return rc;
-	}
-
-	return cxl_setup_regs(map);
-}
-
 static void free_event_buf(void *buf)
 {
 	kvfree(buf);
@@ -865,25 +795,25 @@ 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..fa7269154620
--- /dev/null
+++ b/include/cxl/cxl.h
@@ -0,0 +1,226 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2020 Intel Corporation. */
+/* Copyright(c) 2026 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_device_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: name of the struct cxl_dev_state member in drv_struct
+ * @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;