In preparation for moving lockdep_mutex nested lock acquisition into the
core, remove the cxl_device_lock() wrapper, but preserve
cxl_lock_class() that will be used to inform the core of the subsystem's
lock ordering rules.

Note that this reverts back to the default state of unvalidated
device_lock(). A follow-on change to use the new dev->lock_class
facility re-enables lockdep validation.

Cc: Alison Schofield <alison.schofi...@intel.com>
Cc: Vishal Verma <vishal.l.ve...@intel.com>
Cc: Ira Weiny <ira.we...@intel.com>
Cc: Ben Widawsky <ben.widaw...@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.came...@huawei.com>
Reviewed-by: Dave Jiang <dave.ji...@intel.com>
Reviewed-by: Kevin Tian <kevin.t...@intel.com>
Signed-off-by: Dan Williams <dan.j.willi...@intel.com>
---
 drivers/cxl/core/pmem.c |    4 ++-
 drivers/cxl/core/port.c |   54 ++++++++++++++++++++---------------------------
 drivers/cxl/cxl.h       |   46 ----------------------------------------
 drivers/cxl/mem.c       |    4 ++-
 drivers/cxl/pmem.c      |   12 +++++-----
 lib/Kconfig.debug       |    2 +-
 6 files changed, 34 insertions(+), 88 deletions(-)

diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c
index 8de240c4d96b..60f71caa5dbd 100644
--- a/drivers/cxl/core/pmem.c
+++ b/drivers/cxl/core/pmem.c
@@ -121,10 +121,10 @@ static void unregister_nvb(void *_cxl_nvb)
         * work to flush. Once the state has been changed to 'dead' then no new
         * work can be queued by user-triggered bind.
         */
-       cxl_device_lock(&cxl_nvb->dev);
+       device_lock(&cxl_nvb->dev);
        flush = cxl_nvb->state != CXL_NVB_NEW;
        cxl_nvb->state = CXL_NVB_DEAD;
-       cxl_device_unlock(&cxl_nvb->dev);
+       device_unlock(&cxl_nvb->dev);
 
        /*
         * Even though the device core will trigger device_release_driver()
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 2ab1ba4499b3..437e8a71e5dc 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);
 }
@@ -554,7 +554,7 @@ 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 +564,7 @@ static int match_root_child(struct device *dev, const void 
*match)
                }
        }
 out:
-       cxl_device_unlock(dev);
+       device_unlock(dev);
 
        return !!iter;
 }
@@ -623,13 +623,13 @@ 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 +736,15 @@ 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 +854,12 @@ 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 +920,7 @@ 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 +928,12 @@ 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 +948,7 @@ 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 +956,7 @@ 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 +1004,7 @@ 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 +1022,7 @@ 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 +1133,14 @@ 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);
@@ -1379,9 +1379,9 @@ 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;
 }
@@ -1452,13 +1452,7 @@ static int cxl_bus_probe(struct device *dev)
 {
        int rc;
 
-       /*
-        * Take the CXL nested lock since the driver core only holds
-        * @dev->mutex and not @dev->lockdep_mutex.
-        */
-       cxl_nested_lock(dev);
        rc = to_cxl_drv(dev->driver)->probe(dev);
-       cxl_nested_unlock(dev);
 
        dev_dbg(dev, "probe: %d\n", rc);
        return rc;
@@ -1468,10 +1462,8 @@ static void cxl_bus_remove(struct device *dev)
 {
        struct cxl_driver *cxl_drv = to_cxl_drv(dev->driver);
 
-       cxl_nested_lock(dev);
        if (cxl_drv->remove)
                cxl_drv->remove(dev);
-       cxl_nested_unlock(dev);
 }
 
 static struct workqueue_struct *cxl_bus_wq;
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index c9fda9304c54..a6c1a027e389 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -439,51 +439,5 @@ static inline int cxl_lock_class(struct device *dev)
        else
                return CXL_ANON_LOCK;
 }
-
-static inline void cxl_nested_lock(struct device *dev)
-{
-       mutex_lock_nested(&dev->lockdep_mutex, cxl_lock_class(dev));
-}
-
-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__ */
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 49a4b1c47299..91fb8d5b21a7 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -195,7 +195,7 @@ static int cxl_mem_probe(struct device *dev)
                return -ENXIO;
        }
 
-       cxl_device_lock(&parent_port->dev);
+       device_lock(&parent_port->dev);
        if (!parent_port->dev.driver) {
                dev_err(dev, "CXL port topology %s not enabled\n",
                        dev_name(&parent_port->dev));
@@ -205,7 +205,7 @@ static int cxl_mem_probe(struct device *dev)
 
        rc = create_endpoint(cxlmd, parent_port);
 out:
-       cxl_device_unlock(&parent_port->dev);
+       device_unlock(&parent_port->dev);
        put_device(&parent_port->dev);
        return rc;
 }
diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
index 15ad666ab03e..b65a272a2d6d 100644
--- a/drivers/cxl/pmem.c
+++ b/drivers/cxl/pmem.c
@@ -43,7 +43,7 @@ static int cxl_nvdimm_probe(struct device *dev)
        if (!cxl_nvb)
                return -ENXIO;
 
-       cxl_device_lock(&cxl_nvb->dev);
+       device_lock(&cxl_nvb->dev);
        if (!cxl_nvb->nvdimm_bus) {
                rc = -ENXIO;
                goto out;
@@ -68,7 +68,7 @@ static int cxl_nvdimm_probe(struct device *dev)
        dev_set_drvdata(dev, nvdimm);
        rc = devm_add_action_or_reset(dev, unregister_nvdimm, nvdimm);
 out:
-       cxl_device_unlock(&cxl_nvb->dev);
+       device_unlock(&cxl_nvb->dev);
        put_device(&cxl_nvb->dev);
 
        return rc;
@@ -233,7 +233,7 @@ static void cxl_nvb_update_state(struct work_struct *work)
        struct nvdimm_bus *victim_bus = NULL;
        bool release = false, rescan = false;
 
-       cxl_device_lock(&cxl_nvb->dev);
+       device_lock(&cxl_nvb->dev);
        switch (cxl_nvb->state) {
        case CXL_NVB_ONLINE:
                if (!online_nvdimm_bus(cxl_nvb)) {
@@ -251,7 +251,7 @@ static void cxl_nvb_update_state(struct work_struct *work)
        default:
                break;
        }
-       cxl_device_unlock(&cxl_nvb->dev);
+       device_unlock(&cxl_nvb->dev);
 
        if (release)
                device_release_driver(&cxl_nvb->dev);
@@ -327,9 +327,9 @@ static int cxl_nvdimm_bridge_reset(struct device *dev, void 
*data)
                return 0;
 
        cxl_nvb = to_cxl_nvdimm_bridge(dev);
-       cxl_device_lock(dev);
+       device_lock(dev);
        cxl_nvb->state = CXL_NVB_NEW;
-       cxl_device_unlock(dev);
+       device_unlock(dev);
 
        return 0;
 }
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 075cd25363ac..333d41da7621 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1563,7 +1563,7 @@ config PROVE_CXL_LOCKING
        bool "CXL"
        depends on CXL_BUS
        help
-         Enable lockdep to validate cxl_device_lock() usage.
+         Enable lockdep to validate CXL subsystem usage of the device lock.
 
 endchoice
 


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