*Completely* untested (I wouldn't know where to begin and probably odn't
have the hardware anyway), and known incomplete.

What's wrong with something like this then?

---
 drivers/cxl/core/pmem.c |  8 +++++
 drivers/cxl/core/port.c | 58 +++++++++++++++++++++---------------
 drivers/cxl/cxl.h       | 78 -------------------------------------------------
 3 files changed, 42 insertions(+), 102 deletions(-)

diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c
index 8de240c4d96b..aca0dd5eefeb 100644
--- a/drivers/cxl/core/pmem.c
+++ b/drivers/cxl/core/pmem.c
@@ -80,6 +80,8 @@ struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct 
cxl_nvdimm *cxl_nvd)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_find_nvdimm_bridge, CXL);
 
+static lock_class_key cxl_nvdimm_bridge_key;
+
 static struct cxl_nvdimm_bridge *cxl_nvdimm_bridge_alloc(struct cxl_port *port)
 {
        struct cxl_nvdimm_bridge *cxl_nvb;
@@ -104,6 +106,8 @@ static struct cxl_nvdimm_bridge 
*cxl_nvdimm_bridge_alloc(struct cxl_port *port)
        dev->bus = &cxl_bus_type;
        dev->type = &cxl_nvdimm_bridge_type;
 
+       lockdep_set_class(&dev->mutex, &cxl_nvdimm_bridge_key);
+
        return cxl_nvb;
 
 err:
@@ -214,6 +218,8 @@ struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev)
 }
 EXPORT_SYMBOL_NS_GPL(to_cxl_nvdimm, CXL);
 
+static struct lock_class_key cxl_nvdimm_key;
+
 static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd)
 {
        struct cxl_nvdimm *cxl_nvd;
@@ -231,6 +237,8 @@ static struct cxl_nvdimm *cxl_nvdimm_alloc(struct 
cxl_memdev *cxlmd)
        dev->bus = &cxl_bus_type;
        dev->type = &cxl_nvdimm_type;
 
+       lockdep_set_class(&dev->mutex, &cxl_nvdimm_key);
+
        return cxl_nvd;
 }
 
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 2ab1ba4499b3..cae88404612f 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -312,10 +312,10 @@ static void cxl_port_release(struct device *dev)
        struct cxl_port *port = to_cxl_port(dev);
        struct cxl_ep *ep, *_e;
 
-       cxl_device_lock(dev);
+       device_lock(dev);
        list_for_each_entry_safe(ep, _e, &port->endpoints, list)
                cxl_ep_release(ep);
-       cxl_device_unlock(dev);
+       device_unlock(dev);
        ida_free(&cxl_port_ida, port->id);
        kfree(port);
 }
@@ -391,6 +391,8 @@ static int devm_cxl_link_uport(struct device *host, struct 
cxl_port *port)
        return devm_add_action_or_reset(host, cxl_unlink_uport, port);
 }
 
+static struct lock_class_key cxl_port_key;
+
 static struct cxl_port *cxl_port_alloc(struct device *uport,
                                       resource_size_t component_reg_phys,
                                       struct cxl_port *parent_port)
@@ -431,6 +433,8 @@ static struct cxl_port *cxl_port_alloc(struct device *uport,
        dev->bus = &cxl_bus_type;
        dev->type = &cxl_port_type;
 
+       lockdep_set_class(&dev->mutex, &cxl_port_key);
+
        return port;
 
 err:
@@ -457,8 +461,10 @@ struct cxl_port *devm_cxl_add_port(struct device *host, 
struct device *uport,
        if (IS_ERR(port))
                return port;
 
-       if (parent_port)
+       if (parent_port) {
                port->depth = parent_port->depth + 1;
+               lockdep_set_class_and_subclass(&port->dev->mutex, &cxl_port, 
port->depth);
+       }
        dev = &port->dev;
        if (is_cxl_memdev(uport))
                rc = dev_set_name(dev, "endpoint%d", port->id);
@@ -554,7 +560,7 @@ static int match_root_child(struct device *dev, const void 
*match)
                return 0;
 
        port = to_cxl_port(dev);
-       cxl_device_lock(dev);
+       device_lock(dev);
        list_for_each_entry(dport, &port->dports, list) {
                iter = match;
                while (iter) {
@@ -564,7 +570,7 @@ static int match_root_child(struct device *dev, const void 
*match)
                }
        }
 out:
-       cxl_device_unlock(dev);
+       device_unlock(dev);
 
        return !!iter;
 }
@@ -623,13 +629,13 @@ static int add_dport(struct cxl_port *port, struct 
cxl_dport *new)
 static void cond_cxl_root_lock(struct cxl_port *port)
 {
        if (is_cxl_root(port))
-               cxl_device_lock(&port->dev);
+               device_lock(&port->dev);
 }
 
 static void cond_cxl_root_unlock(struct cxl_port *port)
 {
        if (is_cxl_root(port))
-               cxl_device_unlock(&port->dev);
+               device_unlock(&port->dev);
 }
 
 static void cxl_dport_remove(void *data)
@@ -736,15 +742,15 @@ static int add_ep(struct cxl_port *port, struct cxl_ep 
*new)
 {
        struct cxl_ep *dup;
 
-       cxl_device_lock(&port->dev);
+       device_lock(&port->dev);
        if (port->dead) {
-               cxl_device_unlock(&port->dev);
+               device_unlock(&port->dev);
                return -ENXIO;
        }
        dup = find_ep(port, new->ep);
        if (!dup)
                list_add_tail(&new->list, &port->endpoints);
-       cxl_device_unlock(&port->dev);
+       device_unlock(&port->dev);
 
        return dup ? -EEXIST : 0;
 }
@@ -854,12 +860,12 @@ static void delete_endpoint(void *data)
                goto out;
        parent = &parent_port->dev;
 
-       cxl_device_lock(parent);
+       device_lock(parent);
        if (parent->driver && endpoint->uport) {
                devm_release_action(parent, cxl_unlink_uport, endpoint);
                devm_release_action(parent, unregister_port, endpoint);
        }
-       cxl_device_unlock(parent);
+       device_unlock(parent);
        put_device(parent);
 out:
        put_device(&endpoint->dev);
@@ -920,7 +926,7 @@ static void cxl_detach_ep(void *data)
                }
 
                parent_port = to_cxl_port(port->dev.parent);
-               cxl_device_lock(&parent_port->dev);
+               device_lock(&parent_port->dev);
                if (!parent_port->dev.driver) {
                        /*
                         * The bottom-up race to delete the port lost to a
@@ -928,12 +934,12 @@ static void cxl_detach_ep(void *data)
                         * parent_port ->remove() will have cleaned up all
                         * descendants.
                         */
-                       cxl_device_unlock(&parent_port->dev);
+                       device_unlock(&parent_port->dev);
                        put_device(&port->dev);
                        continue;
                }
 
-               cxl_device_lock(&port->dev);
+               device_lock(&port->dev);
                ep = find_ep(port, &cxlmd->dev);
                dev_dbg(&cxlmd->dev, "disconnect %s from %s\n",
                        ep ? dev_name(ep->ep) : "", dev_name(&port->dev));
@@ -948,7 +954,7 @@ static void cxl_detach_ep(void *data)
                        port->dead = true;
                        list_splice_init(&port->dports, &reap_dports);
                }
-               cxl_device_unlock(&port->dev);
+               device_unlock(&port->dev);
 
                if (!list_empty(&reap_dports)) {
                        dev_dbg(&cxlmd->dev, "delete %s\n",
@@ -956,7 +962,7 @@ static void cxl_detach_ep(void *data)
                        delete_switch_port(port, &reap_dports);
                }
                put_device(&port->dev);
-               cxl_device_unlock(&parent_port->dev);
+               device_unlock(&parent_port->dev);
        }
 }
 
@@ -1004,7 +1010,7 @@ static int add_port_attach_ep(struct cxl_memdev *cxlmd,
                return -EAGAIN;
        }
 
-       cxl_device_lock(&parent_port->dev);
+       device_lock(&parent_port->dev);
        if (!parent_port->dev.driver) {
                dev_warn(&cxlmd->dev,
                         "port %s:%s disabled, failed to enumerate CXL.mem\n",
@@ -1022,7 +1028,7 @@ static int add_port_attach_ep(struct cxl_memdev *cxlmd,
                        get_device(&port->dev);
        }
 out:
-       cxl_device_unlock(&parent_port->dev);
+       device_unlock(&parent_port->dev);
 
        if (IS_ERR(port))
                rc = PTR_ERR(port);
@@ -1133,14 +1139,14 @@ struct cxl_dport *cxl_find_dport_by_dev(struct cxl_port 
*port,
 {
        struct cxl_dport *dport;
 
-       cxl_device_lock(&port->dev);
+       device_lock(&port->dev);
        list_for_each_entry(dport, &port->dports, list)
                if (dport->dport == dev) {
-                       cxl_device_unlock(&port->dev);
+                       device_unlock(&port->dev);
                        return dport;
                }
 
-       cxl_device_unlock(&port->dev);
+       device_unlock(&port->dev);
        return NULL;
 }
 EXPORT_SYMBOL_NS_GPL(cxl_find_dport_by_dev, CXL);
@@ -1173,6 +1179,8 @@ static int decoder_populate_targets(struct cxl_decoder 
*cxld,
        return rc;
 }
 
+static struct lock_class_key cxl_decoder_key;
+
 /**
  * cxl_decoder_alloc - Allocate a new CXL decoder
  * @port: owning port of this decoder
@@ -1224,6 +1232,8 @@ static struct cxl_decoder *cxl_decoder_alloc(struct 
cxl_port *port,
        else
                cxld->dev.type = &cxl_decoder_switch_type;
 
+       lockdep_set_class(&dev->mutex, cxl_decoder_key);
+
        /* Pre initialize an "empty" decoder */
        cxld->interleave_ways = 1;
        cxld->interleave_granularity = PAGE_SIZE;
@@ -1379,9 +1389,9 @@ int cxl_decoder_add(struct cxl_decoder *cxld, int 
*target_map)
 
        port = to_cxl_port(cxld->dev.parent);
 
-       cxl_device_lock(&port->dev);
+       device_lock(&port->dev);
        rc = cxl_decoder_add_locked(cxld, target_map);
-       cxl_device_unlock(&port->dev);
+       device_unlock(&port->dev);
 
        return rc;
 }
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 990b6670222e..140dc3278cde 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -405,82 +405,4 @@ struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct 
cxl_nvdimm *cxl_nvd);
 #define __mock static
 #endif
 
-#ifdef CONFIG_PROVE_CXL_LOCKING
-enum cxl_lock_class {
-       CXL_ANON_LOCK,
-       CXL_NVDIMM_LOCK,
-       CXL_NVDIMM_BRIDGE_LOCK,
-       CXL_PORT_LOCK,
-       /*
-        * Be careful to add new lock classes here, CXL_PORT_LOCK is
-        * extended by the port depth, so a maximum CXL port topology
-        * depth would need to be defined first.
-        */
-};
-
-static inline void cxl_nested_lock(struct device *dev)
-{
-       if (is_cxl_port(dev)) {
-               struct cxl_port *port = to_cxl_port(dev);
-
-               mutex_lock_nested(&dev->lockdep_mutex,
-                                 CXL_PORT_LOCK + port->depth);
-       } else if (is_cxl_decoder(dev)) {
-               struct cxl_port *port = to_cxl_port(dev->parent);
-
-               /*
-                * A decoder is the immediate child of a port, so set
-                * its lock class equal to other child device siblings.
-                */
-               mutex_lock_nested(&dev->lockdep_mutex,
-                                 CXL_PORT_LOCK + port->depth + 1);
-       } else if (is_cxl_nvdimm_bridge(dev))
-               mutex_lock_nested(&dev->lockdep_mutex, CXL_NVDIMM_BRIDGE_LOCK);
-       else if (is_cxl_nvdimm(dev))
-               mutex_lock_nested(&dev->lockdep_mutex, CXL_NVDIMM_LOCK);
-       else
-               mutex_lock_nested(&dev->lockdep_mutex, CXL_ANON_LOCK);
-}
-
-static inline void cxl_nested_unlock(struct device *dev)
-{
-       mutex_unlock(&dev->lockdep_mutex);
-}
-
-static inline void cxl_device_lock(struct device *dev)
-{
-       /*
-        * For double lock errors the lockup will happen before lockdep
-        * warns at cxl_nested_lock(), so assert explicitly.
-        */
-       lockdep_assert_not_held(&dev->lockdep_mutex);
-
-       device_lock(dev);
-       cxl_nested_lock(dev);
-}
-
-static inline void cxl_device_unlock(struct device *dev)
-{
-       cxl_nested_unlock(dev);
-       device_unlock(dev);
-}
-#else
-static inline void cxl_nested_lock(struct device *dev)
-{
-}
-
-static inline void cxl_nested_unlock(struct device *dev)
-{
-}
-
-static inline void cxl_device_lock(struct device *dev)
-{
-       device_lock(dev);
-}
-
-static inline void cxl_device_unlock(struct device *dev)
-{
-       device_unlock(dev);
-}
-#endif
 #endif /* __CXL_H__ */

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