cxl/port: Use scoped_guard()/guard() to drop device_lock() for cxl_port

A device_lock() and device_unlock() pair can be replaced by a cleanup
helper scoped_guard() or guard(), that can enhance code readability. In
CXL subsystem, still use device_lock() and device_unlock() pairs for cxl
port resource protection, most of them can be replaced by a
scoped_guard() or a guard() simply.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Li Ming <ming4.li@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20240830013138.2256244-2-ming4.li@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index e5cdeafdf76e7dbcc117ccd9af949d34526804aa..0a913b30c7fc127ac572f05ead0546f98123a16b 100644 (file)
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -1214,7 +1214,7 @@ int cxl_mem_sanitize(struct cxl_memdev *cxlmd, u16 cmd)
        int rc;
 
        /* synchronize with cxl_mem_probe() and decoder write operations */
-       device_lock(&cxlmd->dev);
+       guard(device)(&cxlmd->dev);
        endpoint = cxlmd->endpoint;
        down_read(&cxl_region_rwsem);
        /*
@@ -1226,7 +1226,6 @@ int cxl_mem_sanitize(struct cxl_memdev *cxlmd, u16 cmd)
        else
                rc = -EBUSY;
        up_read(&cxl_region_rwsem);
-       device_unlock(&cxlmd->dev);
 
        return rc;
 }

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index e1e7620764766ee1c7efadaed8ca388c1fcad758..ebd7ddadbb544f7417af498c0ad0c22a8ef9eea6 100644 (file)
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -1258,18 +1258,13 @@ EXPORT_SYMBOL_NS_GPL(devm_cxl_add_rch_dport, CXL);
 static int add_ep(struct cxl_ep *new)
 {
        struct cxl_port *port = new->dport->port;
-       int rc;
 
-       device_lock(&port->dev);
-       if (port->dead) {
-               device_unlock(&port->dev);
+       guard(device)(&port->dev);
+       if (port->dead)
                return -ENXIO;
-       }
-       rc = xa_insert(&port->endpoints, (unsigned long)new->ep, new,
-                      GFP_KERNEL);
-       device_unlock(&port->dev);
 
-       return rc;
+       return xa_insert(&port->endpoints, (unsigned long)new->ep,
+                        new, GFP_KERNEL);
 }
 
 /**
@@ -1393,14 +1388,14 @@ static void delete_endpoint(void *data)
        struct cxl_port *endpoint = cxlmd->endpoint;
        struct device *host = endpoint_host(endpoint);
 
-       device_lock(host);
-       if (host->driver && !endpoint->dead) {
-               devm_release_action(host, cxl_unlink_parent_dport, endpoint);
-               devm_release_action(host, cxl_unlink_uport, endpoint);
-               devm_release_action(host, unregister_port, endpoint);
+       scoped_guard(device, host) {
+               if (host->driver && !endpoint->dead) {
+                       devm_release_action(host, cxl_unlink_parent_dport, endpoint);
+                       devm_release_action(host, cxl_unlink_uport, endpoint);
+                       devm_release_action(host, unregister_port, endpoint);
+               }
+               cxlmd->endpoint = NULL;
        }
-       cxlmd->endpoint = NULL;
-       device_unlock(host);
        put_device(&endpoint->dev);
        put_device(host);
 }
@@ -1565,40 +1560,38 @@ static int add_port_attach_ep(struct cxl_memdev *cxlmd,
         * dereferencing the device of the port before the parent_port releasing.
         */
        struct cxl_port *port __free(put_cxl_port) = NULL;
-       device_lock(&parent_port->dev);
-       if (!parent_port->dev.driver) {
-               dev_warn(&cxlmd->dev,
-                        "port %s:%s disabled, failed to enumerate CXL.mem\n",
-                        dev_name(&parent_port->dev), dev_name(uport_dev));
-               port = ERR_PTR(-ENXIO);
-               goto out;
-       }
+       scoped_guard(device, &parent_port->dev) {
+               if (!parent_port->dev.driver) {
+                       dev_warn(&cxlmd->dev,
+                                "port %s:%s disabled, failed to enumerate CXL.mem\n",
+                                dev_name(&parent_port->dev), dev_name(uport_dev));
+                       return -ENXIO;
+               }
+
+               port = find_cxl_port_at(parent_port, dport_dev, &dport);
+               if (!port) {
+                       component_reg_phys = find_component_registers(uport_dev);
+                       port = devm_cxl_add_port(&parent_port->dev, uport_dev,
+                                                component_reg_phys, parent_dport);
+                       if (IS_ERR(port))
+                               return PTR_ERR(port);
 
-       port = find_cxl_port_at(parent_port, dport_dev, &dport);
-       if (!port) {
-               component_reg_phys = find_component_registers(uport_dev);
-               port = devm_cxl_add_port(&parent_port->dev, uport_dev,
-                                        component_reg_phys, parent_dport);
-               /* retry find to pick up the new dport information */
-               if (!IS_ERR(port))
+                       /* retry find to pick up the new dport information */
                        port = find_cxl_port_at(parent_port, dport_dev, &dport);
+                       if (!port)
+                               return -ENXIO;
+               }
        }
-out:
-       device_unlock(&parent_port->dev);
 
-       if (IS_ERR(port))
-               rc = PTR_ERR(port);
-       else {
-               dev_dbg(&cxlmd->dev, "add to new port %s:%s\n",
-                       dev_name(&port->dev), dev_name(port->uport_dev));
-               rc = cxl_add_ep(dport, &cxlmd->dev);
-               if (rc == -EBUSY) {
-                       /*
-                        * "can't" happen, but this error code means
-                        * something to the caller, so translate it.
-                        */
-                       rc = -ENXIO;
-               }
+       dev_dbg(&cxlmd->dev, "add to new port %s:%s\n",
+               dev_name(&port->dev), dev_name(port->uport_dev));
+       rc = cxl_add_ep(dport, &cxlmd->dev);
+       if (rc == -EBUSY) {
+               /*
+                * "can't" happen, but this error code means
+                * something to the caller, so translate it.
+                */
+               rc = -ENXIO;
        }
 
        return rc;
@@ -1979,7 +1972,6 @@ EXPORT_SYMBOL_NS_GPL(cxl_decoder_add_locked, CXL);
 int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map)
 {
        struct cxl_port *port;
-       int rc;
 
        if (WARN_ON_ONCE(!cxld))
                return -EINVAL;
@@ -1989,11 +1981,8 @@ int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map)
 
        port = to_cxl_port(cxld->dev.parent);
 
-       device_lock(&port->dev);
-       rc = cxl_decoder_add_locked(cxld, target_map);
-       device_unlock(&port->dev);
-
-       return rc;
+       guard(device)(&port->dev);
+       return cxl_decoder_add_locked(cxld, target_map);
 }
 EXPORT_SYMBOL_NS_GPL(cxl_decoder_add, CXL);
 

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 21ad5f24287581e179b00d6f651a47a90a12f720..9a7c001eff1e77479c6290c58536d6f1cc97fc42 100644 (file)
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -3094,11 +3094,11 @@ static void cxlr_release_nvdimm(void *_cxlr)
        struct cxl_region *cxlr = _cxlr;
        struct cxl_nvdimm_bridge *cxl_nvb = cxlr->cxl_nvb;
 
-       device_lock(&cxl_nvb->dev);
-       if (cxlr->cxlr_pmem)
-               devm_release_action(&cxl_nvb->dev, cxlr_pmem_unregister,
-                                   cxlr->cxlr_pmem);
-       device_unlock(&cxl_nvb->dev);
+       scoped_guard(device, &cxl_nvb->dev) {
+               if (cxlr->cxlr_pmem)
+                       devm_release_action(&cxl_nvb->dev, cxlr_pmem_unregister,
+                                           cxlr->cxlr_pmem);
+       }
        cxlr->cxl_nvb = NULL;
        put_device(&cxl_nvb->dev);
 }
@@ -3134,13 +3134,14 @@ static int devm_cxl_add_pmem_region(struct cxl_region *cxlr)
        dev_dbg(&cxlr->dev, "%s: register %s\n", dev_name(dev->parent),
                dev_name(dev));
 
-       device_lock(&cxl_nvb->dev);
-       if (cxl_nvb->dev.driver)
-               rc = devm_add_action_or_reset(&cxl_nvb->dev,
-                                             cxlr_pmem_unregister, cxlr_pmem);
-       else
-               rc = -ENXIO;
-       device_unlock(&cxl_nvb->dev);
+       scoped_guard(device, &cxl_nvb->dev) {
+               if (cxl_nvb->dev.driver)
+                       rc = devm_add_action_or_reset(&cxl_nvb->dev,
+                                                     cxlr_pmem_unregister,
+                                                     cxlr_pmem);
+               else
+                       rc = -ENXIO;
+       }
 
        if (rc)
                goto err_bridge;

diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index ab9b8ab8df44ee24d7e057a618a40bbdaaabdced..ae94018a01bdf69dced3c21b21ef877c35c93a2d 100644 (file)
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -168,19 +168,17 @@ static int cxl_mem_probe(struct device *dev)
 
        cxl_setup_parent_dport(dev, dport);
 
-       device_lock(endpoint_parent);
-       if (!endpoint_parent->driver) {
-               dev_err(dev, "CXL port topology %s not enabled\n",
-                       dev_name(endpoint_parent));
-               rc = -ENXIO;
-               goto unlock;
-       }
+       scoped_guard(device, endpoint_parent) {
+               if (!endpoint_parent->driver) {
+                       dev_err(dev, "CXL port topology %s not enabled\n",
+                               dev_name(endpoint_parent));
+                       return -ENXIO;
+               }
 
-       rc = devm_cxl_add_endpoint(endpoint_parent, cxlmd, dport);
-unlock:
-       device_unlock(endpoint_parent);
-       if (rc)
-               return rc;
+               rc = devm_cxl_add_endpoint(endpoint_parent, cxlmd, dport);
+               if (rc)
+                       return rc;
+       }
 
        /*
         * The kernel may be operating out of CXL memory on this device,

diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
index 4ef93da2233558c6868a3e0878d848b53de79474..647c7e25ef3a7cec52dabfa1a5e99bbe47e09f37 100644 (file)
--- a/drivers/cxl/pmem.c
+++ b/drivers/cxl/pmem.c
@@ -233,15 +233,13 @@ static int detach_nvdimm(struct device *dev, void *data)
        if (!is_cxl_nvdimm(dev))
                return 0;
 
-       device_lock(dev);
-       if (!dev->driver)
-               goto out;
-
-       cxl_nvd = to_cxl_nvdimm(dev);
-       if (cxl_nvd->cxlmd && cxl_nvd->cxlmd->cxl_nvb == data)
-               release = true;
-out:
-       device_unlock(dev);
+       scoped_guard(device, dev) {
+               if (dev->driver) {
+                       cxl_nvd = to_cxl_nvdimm(dev);
+                       if (cxl_nvd->cxlmd && cxl_nvd->cxlmd->cxl_nvb == data)
+                               release = true;
+               }
+       }
        if (release)
                device_release_driver(dev);
        return 0;