[PATCH v2 1/3] cxl/port: Use __free() to drop put_device() for cxl_port

Li Ming
2024-08-26T09:01:18Z

Using scope-based resource management __free() marco with a new helper
called put_cxl_port() to drop open coded the put_device() used to
dereference the 'struct device' in cxl_port.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Li Ming <ming4.li@intel.com>
---
v2:
- Use guard() instead of scoped_guard() in some cases.
- Ira: Check the return value of find_cxl_port_at().
Link to v1: https://lore.kernel.org/linux-cxl/8ac82c61-7871-4914-b376-32431868622c@intel.com/T/#m07695675435bf702311dfc40f64289b9623afa16
---
drivers/cxl/core/pci.c | 6 ++----
drivers/cxl/core/port.c | 26 +++++++++-----------------
drivers/cxl/cxl.h | 1 +
drivers/cxl/mem.c | 5 ++---
drivers/cxl/pci.c | 7 ++-----
5 files changed, 16 insertions(+), 29 deletions(-)

diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 51132a575b27..4725e37d90fb 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -915,15 +915,13 @@ static void cxl_handle_rdport_errors(struct cxl_dev_state *cxlds)
struct pci_dev *pdev = to_pci_dev(cxlds->dev);
struct aer_capability_regs aer_regs;
struct cxl_dport *dport;
- struct cxl_port *port;
int severity;

- port = cxl_pci_find_port(pdev, &dport);
+ struct cxl_port *port __free(put_cxl_port) =
+ cxl_pci_find_port(pdev, &dport);
if (!port)
return;

- put_device(&port->dev);
-
if (!cxl_rch_get_aer_info(dport->regs.dport_aer, &aer_regs))
return;

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 1d5007e3795a..b50dda6610e3 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -1477,12 +1477,11 @@ static void cxl_detach_ep(void *data)
.cxlmd = cxlmd,
.depth = i,
};
- struct device *dev;
struct cxl_ep *ep;
bool died = false;

- dev = bus_find_device(&cxl_bus_type, NULL, &ctx,
- port_has_memdev);
+ struct device *dev __free(put_device) =
+ bus_find_device(&cxl_bus_type, NULL, &ctx, port_has_memdev);
if (!dev)
continue;
port = to_cxl_port(dev);
@@ -1512,7 +1511,6 @@ static void cxl_detach_ep(void *data)
dev_name(&port->dev));
delete_switch_port(port);
}
- put_device(&port->dev);
device_unlock(&parent_port->dev);
}
}
@@ -1539,8 +1537,8 @@ static int add_port_attach_ep(struct cxl_memdev *cxlmd,
struct device *uport_dev,
struct device *dport_dev)
{
+ struct cxl_port *port __free(put_cxl_port) = NULL;
struct device *dparent = grandparent(dport_dev);
- struct cxl_port *port, *parent_port = NULL;
struct cxl_dport *dport, *parent_dport;
resource_size_t component_reg_phys;
int rc;
@@ -1556,7 +1554,8 @@ static int add_port_attach_ep(struct cxl_memdev *cxlmd,
return -ENXIO;
}

- parent_port = find_cxl_port(dparent, &parent_dport);
+ struct cxl_port *parent_port __free(put_cxl_port) =
+ find_cxl_port(dparent, &parent_dport);
if (!parent_port) {
/* iterate to create this parent_port */
return -EAGAIN;
@@ -1596,10 +1595,8 @@ static int add_port_attach_ep(struct cxl_memdev *cxlmd,
*/
rc = -ENXIO;
}
- put_device(&port->dev);
}

- put_device(&parent_port->dev);
return rc;
}

@@ -1630,7 +1627,6 @@ int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd)
struct device *dport_dev = grandparent(iter);
struct device *uport_dev;
struct cxl_dport *dport;
- struct cxl_port *port;

/*
* The terminal "grandparent" in PCI is NULL and @platform_bus
@@ -1649,7 +1645,8 @@ int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd)
dev_dbg(dev, "scan: iter: %s dport_dev: %s parent: %s\n",
dev_name(iter), dev_name(dport_dev),
dev_name(uport_dev));
- port = find_cxl_port(dport_dev, &dport);
+ struct cxl_port *port __free(put_cxl_port) =
+ find_cxl_port(dport_dev, &dport);
if (port) {
dev_dbg(&cxlmd->dev,
"found already registered port %s:%s\n",
@@ -1664,18 +1661,13 @@ int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd)
* the parent_port lock as the current port may be being
* reaped.
*/
- if (rc && rc != -EBUSY) {
- put_device(&port->dev);
+ if (rc && rc != -EBUSY)
return rc;
- }

/* Any more ports to add between this one and the root? */
- if (!dev_is_cxl_root_child(&port->dev)) {
- put_device(&port->dev);
+ if (!dev_is_cxl_root_child(&port->dev))
continue;
- }

- put_device(&port->dev);
return 0;
}

diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 9afb407d438f..84cf3b4d60a1 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -744,6 +744,7 @@ struct cxl_root *find_cxl_root(struct cxl_port *port);
void put_cxl_root(struct cxl_root *cxl_root);
DEFINE_FREE(put_cxl_root, struct cxl_root *, if (_T) put_cxl_root(_T))

+DEFINE_FREE(put_cxl_port, struct cxl_port *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev))
int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd);
void cxl_bus_rescan(void);
void cxl_bus_drain(void);
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 7de232eaeb17..ab9b8ab8df44 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -109,7 +109,6 @@ static int cxl_mem_probe(struct device *dev)
struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
struct cxl_dev_state *cxlds = cxlmd->cxlds;
struct device *endpoint_parent;
- struct cxl_port *parent_port;
struct cxl_dport *dport;
struct dentry *dentry;
int rc;
@@ -146,7 +145,8 @@ static int cxl_mem_probe(struct device *dev)
if (rc)
return rc;

- parent_port = cxl_mem_find_port(cxlmd, &dport);
+ struct cxl_port *parent_port __free(put_cxl_port) =
+ cxl_mem_find_port(cxlmd, &dport);
if (!parent_port) {
dev_err(dev, "CXL port topology not found\n");
return -ENXIO;
@@ -179,7 +179,6 @@ static int cxl_mem_probe(struct device *dev)
rc = devm_cxl_add_endpoint(endpoint_parent, cxlmd, dport);
unlock:
device_unlock(endpoint_parent);
- put_device(&parent_port->dev);
if (rc)
return rc;

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 4be35dc22202..26e75499abdd 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -473,7 +473,6 @@ static bool is_cxl_restricted(struct pci_dev *pdev)
static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
struct cxl_register_map *map)
{
- struct cxl_port *port;
struct cxl_dport *dport;
resource_size_t component_reg_phys;

@@ -482,14 +481,12 @@ static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
.resource = CXL_RESOURCE_NONE,
};

- port = cxl_pci_find_port(pdev, &dport);
+ struct cxl_port *port __free(put_cxl_port) =
+ cxl_pci_find_port(pdev, &dport);
if (!port)
return -EPROBE_DEFER;

component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
-
- put_device(&port->dev);
-
if (component_reg_phys == CXL_RESOURCE_NONE)
return -ENXIO;

--
2.40.1