* [PATCH v3 2/3] cxl/port: Use scoped_guard()/guard() to drop device_lock() for cxl_port
2024-08-30 1:31 [PATCH v3 1/3] cxl/port: Use __free() to drop put_device() for cxl_port Li Ming
@ 2024-08-30 1:31 ` Li Ming
2024-08-30 1:31 ` [PATCH v3 3/3] cxl/port: Refactor __devm_cxl_add_port() to drop goto pattern Li Ming
2024-08-30 11:01 ` [PATCH v3 1/3] cxl/port: Use __free() to drop put_device() for cxl_port Jonathan Cameron
2 siblings, 0 replies; 4+ messages in thread
From: Li Ming @ 2024-08-30 1:31 UTC (permalink / raw)
To: dave, jonathan.cameron, dave.jiang, alison.schofield,
vishal.l.verma, ira.weiny, dan.j.williams
Cc: linux-cxl, Li Ming, Jonathan Cameron
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>
---
drivers/cxl/core/mbox.c | 3 +-
drivers/cxl/core/port.c | 93 +++++++++++++++++----------------------
drivers/cxl/core/region.c | 25 ++++++-----
drivers/cxl/mem.c | 22 +++++----
drivers/cxl/pmem.c | 16 +++----
5 files changed, 72 insertions(+), 87 deletions(-)
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index e5cdeafdf76e..0a913b30c7fc 100644
--- 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 ffd322aaed42..d02fb85e8c8d 100644
--- 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 21ad5f242875..9a7c001eff1e 100644
--- 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 ab9b8ab8df44..ae94018a01bd 100644
--- 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 4ef93da22335..647c7e25ef3a 100644
--- 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;
--
2.40.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v3 3/3] cxl/port: Refactor __devm_cxl_add_port() to drop goto pattern
2024-08-30 1:31 [PATCH v3 1/3] cxl/port: Use __free() to drop put_device() for cxl_port Li Ming
2024-08-30 1:31 ` [PATCH v3 2/3] cxl/port: Use scoped_guard()/guard() to drop device_lock() " Li Ming
@ 2024-08-30 1:31 ` Li Ming
2024-08-30 11:01 ` [PATCH v3 1/3] cxl/port: Use __free() to drop put_device() for cxl_port Jonathan Cameron
2 siblings, 0 replies; 4+ messages in thread
From: Li Ming @ 2024-08-30 1:31 UTC (permalink / raw)
To: dave, jonathan.cameron, dave.jiang, alison.schofield,
vishal.l.verma, ira.weiny, dan.j.williams
Cc: linux-cxl, Li Ming, Jonathan Cameron
In __devm_cxl_add_port(), there is a 'goto' to call put_device() for the
error cases between device_initialize() and device_add() to dereference
the 'struct device' of a new cxl_port. The 'goto' pattern in the case
can be removed by refactoring. Introducing a new function called
cxl_port_add() which is used to add the 'struct device' of a new
cxl_port to device hierarchy, moving the functions needing the help of
the 'goto' into cxl_port_add(), and using a scoped-based resource
management __free() to drop the open coded put_device() and the 'goto'
for the error cases.
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Li Ming <ming4.li@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huwaei.com>
---
drivers/cxl/core/port.c | 59 ++++++++++++++++++++++++-----------------
1 file changed, 35 insertions(+), 24 deletions(-)
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index d02fb85e8c8d..611da602bf8f 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -828,27 +828,20 @@ static void cxl_debugfs_create_dport_dir(struct cxl_dport *dport)
&cxl_einj_inject_fops);
}
-static struct cxl_port *__devm_cxl_add_port(struct device *host,
- struct device *uport_dev,
- resource_size_t component_reg_phys,
- struct cxl_dport *parent_dport)
+static int cxl_port_add(struct cxl_port *port,
+ resource_size_t component_reg_phys,
+ struct cxl_dport *parent_dport)
{
- struct cxl_port *port;
- struct device *dev;
+ struct device *dev __free(put_device) = &port->dev;
int rc;
- port = cxl_port_alloc(uport_dev, parent_dport);
- if (IS_ERR(port))
- return port;
-
- dev = &port->dev;
- if (is_cxl_memdev(uport_dev)) {
- struct cxl_memdev *cxlmd = to_cxl_memdev(uport_dev);
+ if (is_cxl_memdev(port->uport_dev)) {
+ struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
rc = dev_set_name(dev, "endpoint%d", port->id);
if (rc)
- goto err;
+ return rc;
/*
* The endpoint driver already enumerated the component and RAS
@@ -861,19 +854,41 @@ static struct cxl_port *__devm_cxl_add_port(struct device *host,
} else if (parent_dport) {
rc = dev_set_name(dev, "port%d", port->id);
if (rc)
- goto err;
+ return rc;
rc = cxl_port_setup_regs(port, component_reg_phys);
if (rc)
- goto err;
- } else
+ return rc;
+ } else {
rc = dev_set_name(dev, "root%d", port->id);
- if (rc)
- goto err;
+ if (rc)
+ return rc;
+ }
rc = device_add(dev);
if (rc)
- goto err;
+ return rc;
+
+ /* Inhibit the cleanup function invoked */
+ dev = NULL;
+ return 0;
+}
+
+static struct cxl_port *__devm_cxl_add_port(struct device *host,
+ struct device *uport_dev,
+ resource_size_t component_reg_phys,
+ struct cxl_dport *parent_dport)
+{
+ struct cxl_port *port;
+ int rc;
+
+ port = cxl_port_alloc(uport_dev, parent_dport);
+ if (IS_ERR(port))
+ return port;
+
+ rc = cxl_port_add(port, component_reg_phys, parent_dport);
+ if (rc)
+ return ERR_PTR(rc);
rc = devm_add_action_or_reset(host, unregister_port, port);
if (rc)
@@ -891,10 +906,6 @@ static struct cxl_port *__devm_cxl_add_port(struct device *host,
port->pci_latency = cxl_pci_get_latency(to_pci_dev(uport_dev));
return port;
-
-err:
- put_device(dev);
- return ERR_PTR(rc);
}
/**
--
2.40.1
^ permalink raw reply related [flat|nested] 4+ messages in thread