Commit 38a34e10 authored by Dan Williams's avatar Dan Williams
Browse files

cxl: Drop cxl_device_lock() 



Now that all CXL subsystem locking is validated with custom lock
classes, there is no need for the custom usage of the lockdep_mutex.

Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/165055520383.3745911.53447786039115271.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent d864b8ea

drivers/cxl/core/pmem.c

+2 −2
Original line number Diff line number Diff line
@@ -124,10 +124,10 @@ 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()

drivers/cxl/core/port.c

+23 −32
Original line number Diff line number Diff line
@@ -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);

}
@@ -556,7 +556,7 @@ 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) {
@@ -566,7 +566,7 @@ static int match_root_child(struct device *dev, const void *match) 
		}

	}

out:

	cxl_device_unlock(dev);

	device_unlock(dev);



	return !!iter;

}
@@ -625,13 +625,13 @@ 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)
@@ -738,15 +738,15 @@ 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;

}
@@ -856,12 +856,12 @@ 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);
@@ -922,7 +922,7 @@ 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
@@ -930,12 +930,12 @@ 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));
@@ -950,7 +950,7 @@ 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",
@@ -958,7 +958,7 @@ 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);

	}

}
@@ -1006,7 +1006,7 @@ 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",
@@ -1024,7 +1024,7 @@ 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);
@@ -1135,14 +1135,14 @@ 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);
@@ -1384,9 +1384,9 @@ 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;

}
@@ -1457,14 +1457,7 @@ 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;

}
@@ -1473,10 +1466,8 @@ 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;

drivers/cxl/cxl.h

+0 −78
Original line number Diff line number Diff line
@@ -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__ */

drivers/cxl/mem.c

+2 −2
Original line number Diff line number Diff line
@@ -187,7 +187,7 @@ 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));
@@ -197,7 +197,7 @@ 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);



	/*

drivers/cxl/pmem.c

+6 −6
Original line number Diff line number Diff line
@@ -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;

}