From 1b1bb7b29b1052e4124c0f99eff65200ef141caf Mon Sep 17 00:00:00 2001
From: Brian Norris <briannorris@chromium.org>
Date: Mon, 16 Dec 2024 12:11:42 -0800
Subject: drivers: base: Don't match devices with NULL of_node/fwnode/etc

of_find_device_by_node(), bus_find_device_by_of_node(),
bus_find_device_by_fwnode(), ..., all produce arbitrary results when
provided with a NULL of_node, fwnode, ACPI handle, etc. This is
counterintuitive, and the source of a few bugs, such as the one fixed by
commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device only if
one actually exists").

It's hard to imagine a good reason that these device_match_*() APIs
should return 'true' for a NULL argument. Augment these to return 0
(false).

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Acked-by: David Gow <davidgow@google.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20241216201148.535115-2-briannorris@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/core.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 94865c9d8adc..2b7b13fc36d7 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -5246,13 +5246,13 @@ EXPORT_SYMBOL_GPL(device_match_name);
 
 int device_match_of_node(struct device *dev, const void *np)
 {
-	return dev->of_node == np;
+	return np && dev->of_node == np;
 }
 EXPORT_SYMBOL_GPL(device_match_of_node);
 
 int device_match_fwnode(struct device *dev, const void *fwnode)
 {
-	return dev_fwnode(dev) == fwnode;
+	return fwnode && dev_fwnode(dev) == fwnode;
 }
 EXPORT_SYMBOL_GPL(device_match_fwnode);
 
@@ -5264,13 +5264,13 @@ EXPORT_SYMBOL_GPL(device_match_devt);
 
 int device_match_acpi_dev(struct device *dev, const void *adev)
 {
-	return ACPI_COMPANION(dev) == adev;
+	return adev && ACPI_COMPANION(dev) == adev;
 }
 EXPORT_SYMBOL(device_match_acpi_dev);
 
 int device_match_acpi_handle(struct device *dev, const void *handle)
 {
-	return ACPI_HANDLE(dev) == handle;
+	return handle && ACPI_HANDLE(dev) == handle;
 }
 EXPORT_SYMBOL(device_match_acpi_handle);
 
-- 
cgit v1.2.3


From f1e8bf56320a7fb32095b6c51b707459361b403b Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Tue, 24 Dec 2024 21:05:03 +0800
Subject: driver core: Constify API device_find_child() and adapt for various
 usages
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Constify the following API:
struct device *device_find_child(struct device *dev, void *data,
		int (*match)(struct device *dev, void *data));
To :
struct device *device_find_child(struct device *dev, const void *data,
                                 device_match_t match);
typedef int (*device_match_t)(struct device *dev, const void *data);
with the following reasons:

- Protect caller's match data @*data which is for comparison and lookup
  and the API does not actually need to modify @*data.

- Make the API's parameters (@match)() and @data have the same type as
  all of other device finding APIs (bus|class|driver)_find_device().

- All kinds of existing device match functions can be directly taken
  as the API's argument, they were exported by driver core.

Constify the API and adapt for various existing usages.

BTW, various subsystem changes are squashed into this commit to meet
'git bisect' requirement, and this commit has the minimal and simplest
changes to complement squashing shortcoming, and that may bring extra
code improvement.

Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/sparc/kernel/vio.c                |  6 +++---
 drivers/base/core.c                    |  6 +++---
 drivers/block/sunvdc.c                 |  6 +++---
 drivers/bus/fsl-mc/dprc-driver.c       |  4 ++--
 drivers/cxl/core/pci.c                 |  4 ++--
 drivers/cxl/core/pmem.c                |  2 +-
 drivers/cxl/core/region.c              | 21 ++++++++++++---------
 drivers/firewire/core-device.c         |  4 ++--
 drivers/firmware/arm_scmi/bus.c        |  4 ++--
 drivers/firmware/efi/dev-path-parser.c |  4 ++--
 drivers/gpio/gpio-sim.c                |  2 +-
 drivers/gpu/drm/mediatek/mtk_drm_drv.c |  2 +-
 drivers/hwmon/hwmon.c                  |  2 +-
 drivers/media/pci/mgb4/mgb4_core.c     |  4 ++--
 drivers/nvdimm/bus.c                   |  2 +-
 drivers/pwm/core.c                     |  2 +-
 drivers/rpmsg/rpmsg_core.c             |  4 ++--
 drivers/scsi/qla4xxx/ql4_os.c          |  3 ++-
 drivers/scsi/scsi_transport_iscsi.c    | 10 +++++-----
 drivers/slimbus/core.c                 |  8 ++++----
 drivers/thunderbolt/retimer.c          |  2 +-
 drivers/thunderbolt/xdomain.c          |  2 +-
 drivers/tty/serial/serial_core.c       |  4 ++--
 drivers/usb/typec/class.c              |  8 ++++----
 include/linux/device.h                 |  4 ++--
 include/scsi/scsi_transport_iscsi.h    |  4 ++--
 net/dsa/dsa.c                          |  2 +-
 tools/testing/cxl/test/cxl.c           |  2 +-
 28 files changed, 66 insertions(+), 62 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/arch/sparc/kernel/vio.c b/arch/sparc/kernel/vio.c
index 07933d75ac81..1a1a9d6b8f2e 100644
--- a/arch/sparc/kernel/vio.c
+++ b/arch/sparc/kernel/vio.c
@@ -419,13 +419,13 @@ struct vio_remove_node_data {
 	u64 node;
 };
 
-static int vio_md_node_match(struct device *dev, void *arg)
+static int vio_md_node_match(struct device *dev, const void *arg)
 {
 	struct vio_dev *vdev = to_vio_dev(dev);
-	struct vio_remove_node_data *node_data;
+	const struct vio_remove_node_data *node_data;
 	u64 node;
 
-	node_data = (struct vio_remove_node_data *)arg;
+	node_data = (const struct vio_remove_node_data *)arg;
 
 	node = vio_vdev_node(node_data->hp, vdev);
 
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 2b7b13fc36d7..b242993f816d 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4079,8 +4079,8 @@ EXPORT_SYMBOL_GPL(device_for_each_child_reverse_from);
  *
  * NOTE: you will need to drop the reference with put_device() after use.
  */
-struct device *device_find_child(struct device *parent, void *data,
-				 int (*match)(struct device *dev, void *data))
+struct device *device_find_child(struct device *parent, const void *data,
+				 device_match_t match)
 {
 	struct klist_iter i;
 	struct device *child;
@@ -4125,7 +4125,7 @@ struct device *device_find_child_by_name(struct device *parent,
 }
 EXPORT_SYMBOL_GPL(device_find_child_by_name);
 
-static int match_any(struct device *dev, void *unused)
+static int match_any(struct device *dev, const void *unused)
 {
 	return 1;
 }
diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c
index 2d38331ee667..386643ceed59 100644
--- a/drivers/block/sunvdc.c
+++ b/drivers/block/sunvdc.c
@@ -918,12 +918,12 @@ struct vdc_check_port_data {
 	char	*type;
 };
 
-static int vdc_device_probed(struct device *dev, void *arg)
+static int vdc_device_probed(struct device *dev, const void *arg)
 {
 	struct vio_dev *vdev = to_vio_dev(dev);
-	struct vdc_check_port_data *port_data;
+	const struct vdc_check_port_data *port_data;
 
-	port_data = (struct vdc_check_port_data *)arg;
+	port_data = (const struct vdc_check_port_data *)arg;
 
 	if ((vdev->dev_no == port_data->dev_no) &&
 	    (!(strcmp((char *)&vdev->type, port_data->type))) &&
diff --git a/drivers/bus/fsl-mc/dprc-driver.c b/drivers/bus/fsl-mc/dprc-driver.c
index 11c8fadcf851..52053f7c6d9a 100644
--- a/drivers/bus/fsl-mc/dprc-driver.c
+++ b/drivers/bus/fsl-mc/dprc-driver.c
@@ -112,9 +112,9 @@ void dprc_remove_devices(struct fsl_mc_device *mc_bus_dev,
 }
 EXPORT_SYMBOL_GPL(dprc_remove_devices);
 
-static int __fsl_mc_device_match(struct device *dev, void *data)
+static int __fsl_mc_device_match(struct device *dev, const void *data)
 {
-	struct fsl_mc_obj_desc *obj_desc = data;
+	const struct fsl_mc_obj_desc *obj_desc = data;
 	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
 
 	return fsl_mc_device_match(mc_dev, obj_desc);
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 9d58ab9d33c5..a3c57f96138a 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -252,9 +252,9 @@ static int devm_cxl_enable_mem(struct device *host, struct cxl_dev_state *cxlds)
 }
 
 /* require dvsec ranges to be covered by a locked platform window */
-static int dvsec_range_allowed(struct device *dev, void *arg)
+static int dvsec_range_allowed(struct device *dev, const void *arg)
 {
-	struct range *dev_range = arg;
+	const struct range *dev_range = arg;
 	struct cxl_decoder *cxld;
 
 	if (!is_root_decoder(dev))
diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c
index b3378d3f6acb..a8473de24ebf 100644
--- a/drivers/cxl/core/pmem.c
+++ b/drivers/cxl/core/pmem.c
@@ -57,7 +57,7 @@ bool is_cxl_nvdimm_bridge(struct device *dev)
 }
 EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm_bridge, "CXL");
 
-static int match_nvdimm_bridge(struct device *dev, void *data)
+static int match_nvdimm_bridge(struct device *dev, const void *data)
 {
 	return is_cxl_nvdimm_bridge(dev);
 }
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index d77899650798..bfecd71040c2 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -792,7 +792,7 @@ static int check_commit_order(struct device *dev, const void *data)
 	return 0;
 }
 
-static int match_free_decoder(struct device *dev, void *data)
+static int match_free_decoder(struct device *dev, const void *data)
 {
 	struct cxl_port *port = to_cxl_port(dev->parent);
 	struct cxl_decoder *cxld;
@@ -824,9 +824,9 @@ static int match_free_decoder(struct device *dev, void *data)
 	return 1;
 }
 
-static int match_auto_decoder(struct device *dev, void *data)
+static int match_auto_decoder(struct device *dev, const void *data)
 {
-	struct cxl_region_params *p = data;
+	const struct cxl_region_params *p = data;
 	struct cxl_decoder *cxld;
 	struct range *r;
 
@@ -1722,10 +1722,12 @@ static struct cxl_port *next_port(struct cxl_port *port)
 	return port->parent_dport->port;
 }
 
-static int match_switch_decoder_by_range(struct device *dev, void *data)
+static int match_switch_decoder_by_range(struct device *dev,
+					 const void *data)
 {
 	struct cxl_switch_decoder *cxlsd;
-	struct range *r1, *r2 = data;
+	const struct range *r1, *r2 = data;
+
 
 	if (!is_switch_decoder(dev))
 		return 0;
@@ -3176,9 +3178,10 @@ err:
 	return rc;
 }
 
-static int match_root_decoder_by_range(struct device *dev, void *data)
+static int match_root_decoder_by_range(struct device *dev,
+				       const void *data)
 {
-	struct range *r1, *r2 = data;
+	const struct range *r1, *r2 = data;
 	struct cxl_root_decoder *cxlrd;
 
 	if (!is_root_decoder(dev))
@@ -3189,11 +3192,11 @@ static int match_root_decoder_by_range(struct device *dev, void *data)
 	return range_contains(r1, r2);
 }
 
-static int match_region_by_range(struct device *dev, void *data)
+static int match_region_by_range(struct device *dev, const void *data)
 {
 	struct cxl_region_params *p;
 	struct cxl_region *cxlr;
-	struct range *r = data;
+	const struct range *r = data;
 	int rc = 0;
 
 	if (!is_cxl_region(dev))
diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index a99fe35f1f0d..ec3e21ad2025 100644
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -988,7 +988,7 @@ int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 	return 0;
 }
 
-static int compare_configuration_rom(struct device *dev, void *data)
+static int compare_configuration_rom(struct device *dev, const void *data)
 {
 	const struct fw_device *old = fw_device(dev);
 	const u32 *config_rom = data;
@@ -1039,7 +1039,7 @@ static void fw_device_init(struct work_struct *work)
 	//
 	// serialize config_rom access.
 	scoped_guard(rwsem_read, &fw_device_rwsem) {
-		found = device_find_child(card->device, (void *)device->config_rom,
+		found = device_find_child(card->device, device->config_rom,
 					  compare_configuration_rom);
 	}
 	if (found) {
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 157172a5f2b5..a3386bf36de5 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -238,10 +238,10 @@ static int scmi_dev_match(struct device *dev, const struct device_driver *drv)
 	return 0;
 }
 
-static int scmi_match_by_id_table(struct device *dev, void *data)
+static int scmi_match_by_id_table(struct device *dev, const void *data)
 {
 	struct scmi_device *sdev = to_scmi_dev(dev);
-	struct scmi_device_id *id_table = data;
+	const struct scmi_device_id *id_table = data;
 
 	return sdev->protocol_id == id_table->protocol_id &&
 		(id_table->name && !strcmp(sdev->name, id_table->name));
diff --git a/drivers/firmware/efi/dev-path-parser.c b/drivers/firmware/efi/dev-path-parser.c
index 937be269fee8..13ea141c0def 100644
--- a/drivers/firmware/efi/dev-path-parser.c
+++ b/drivers/firmware/efi/dev-path-parser.c
@@ -47,9 +47,9 @@ static long __init parse_acpi_path(const struct efi_dev_path *node,
 	return 0;
 }
 
-static int __init match_pci_dev(struct device *dev, void *data)
+static int __init match_pci_dev(struct device *dev, const void *data)
 {
-	unsigned int devfn = *(unsigned int *)data;
+	unsigned int devfn = *(const unsigned int *)data;
 
 	return dev_is_pci(dev) && to_pci_dev(dev)->devfn == devfn;
 }
diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
index f387dad81f29..370b71513bdb 100644
--- a/drivers/gpio/gpio-sim.c
+++ b/drivers/gpio/gpio-sim.c
@@ -413,7 +413,7 @@ static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
 	return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);
 }
 
-static int gpio_sim_dev_match_fwnode(struct device *dev, void *data)
+static int gpio_sim_dev_match_fwnode(struct device *dev, const void *data)
 {
 	return device_match_fwnode(dev, data);
 }
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 0829ceb9967c..4aeb393b58e6 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -359,7 +359,7 @@ static const struct of_device_id mtk_drm_of_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, mtk_drm_of_ids);
 
-static int mtk_drm_match(struct device *dev, void *data)
+static int mtk_drm_match(struct device *dev, const void *data)
 {
 	if (!strncmp(dev_name(dev), "mediatek-drm", sizeof("mediatek-drm") - 1))
 		return true;
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index bbb9cc44e29f..6552ee518689 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -341,7 +341,7 @@ static int hwmon_attr_base(enum hwmon_sensor_types type)
 
 static DEFINE_MUTEX(hwmon_pec_mutex);
 
-static int hwmon_match_device(struct device *dev, void *data)
+static int hwmon_match_device(struct device *dev, const void *data)
 {
 	return dev->class == &hwmon_class;
 }
diff --git a/drivers/media/pci/mgb4/mgb4_core.c b/drivers/media/pci/mgb4/mgb4_core.c
index bc63dc81bcae..697d50bedfe2 100644
--- a/drivers/media/pci/mgb4/mgb4_core.c
+++ b/drivers/media/pci/mgb4/mgb4_core.c
@@ -123,7 +123,7 @@ static const struct hwmon_chip_info temp_chip_info = {
 };
 #endif
 
-static int match_i2c_adap(struct device *dev, void *data)
+static int match_i2c_adap(struct device *dev, const void *data)
 {
 	return i2c_verify_adapter(dev) ? 1 : 0;
 }
@@ -139,7 +139,7 @@ static struct i2c_adapter *get_i2c_adap(struct platform_device *pdev)
 	return dev ? to_i2c_adapter(dev) : NULL;
 }
 
-static int match_spi_adap(struct device *dev, void *data)
+static int match_spi_adap(struct device *dev, const void *data)
 {
 	return to_spi_device(dev) ? 1 : 0;
 }
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 2237715e42eb..0ccf4a9e523a 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -1212,7 +1212,7 @@ enum nd_ioctl_mode {
 	DIMM_IOCTL,
 };
 
-static int match_dimm(struct device *dev, void *data)
+static int match_dimm(struct device *dev, const void *data)
 {
 	long id = (long) data;
 
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 675b252d9c8c..14144d0fa38e 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -1276,7 +1276,7 @@ static int pwm_export_child(struct device *pwmchip_dev, struct pwm_device *pwm)
 	return 0;
 }
 
-static int pwm_unexport_match(struct device *pwm_dev, void *data)
+static int pwm_unexport_match(struct device *pwm_dev, const void *data)
 {
 	return pwm_from_dev(pwm_dev) == data;
 }
diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 712c06c02696..207b64c0a2fe 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -377,9 +377,9 @@ EXPORT_SYMBOL(rpmsg_get_mtu);
  * this is used to make sure we're not creating rpmsg devices for channels
  * that already exist.
  */
-static int rpmsg_device_match(struct device *dev, void *data)
+static int rpmsg_device_match(struct device *dev, const void *data)
 {
-	struct rpmsg_channel_info *chinfo = data;
+	const struct rpmsg_channel_info *chinfo = data;
 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
 
 	if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src)
diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index d91f54a6e752..133f36457b28 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -7189,7 +7189,8 @@ exit_new_nt_list:
  *	1: if flashnode entry is non-persistent
  *	0: if flashnode entry is persistent
  **/
-static int qla4xxx_sysfs_ddb_is_non_persistent(struct device *dev, void *data)
+static int qla4xxx_sysfs_ddb_is_non_persistent(struct device *dev,
+					       const void *data)
 {
 	struct iscsi_bus_flash_session *fnode_sess;
 
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index fde7de3b1e55..0d474de2d960 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1324,7 +1324,7 @@ EXPORT_SYMBOL_GPL(iscsi_create_flashnode_conn);
  *  1 on success
  *  0 on failure
  */
-static int iscsi_is_flashnode_conn_dev(struct device *dev, void *data)
+static int iscsi_is_flashnode_conn_dev(struct device *dev, const void *data)
 {
 	return dev->bus == &iscsi_flashnode_bus;
 }
@@ -1335,7 +1335,7 @@ static int iscsi_destroy_flashnode_conn(struct iscsi_bus_flash_conn *fnode_conn)
 	return 0;
 }
 
-static int flashnode_match_index(struct device *dev, void *data)
+static int flashnode_match_index(struct device *dev, const void *data)
 {
 	struct iscsi_bus_flash_session *fnode_sess = NULL;
 	int ret = 0;
@@ -1344,7 +1344,7 @@ static int flashnode_match_index(struct device *dev, void *data)
 		goto exit_match_index;
 
 	fnode_sess = iscsi_dev_to_flash_session(dev);
-	ret = (fnode_sess->target_id == *((int *)data)) ? 1 : 0;
+	ret = (fnode_sess->target_id == *((const int *)data)) ? 1 : 0;
 
 exit_match_index:
 	return ret;
@@ -1389,8 +1389,8 @@ iscsi_get_flashnode_by_index(struct Scsi_Host *shost, uint32_t idx)
  *  %NULL on failure
  */
 struct device *
-iscsi_find_flashnode_sess(struct Scsi_Host *shost, void *data,
-			  int (*fn)(struct device *dev, void *data))
+iscsi_find_flashnode_sess(struct Scsi_Host *shost, const void *data,
+			  device_match_t fn)
 {
 	return device_find_child(&shost->shost_gendev, data, fn);
 }
diff --git a/drivers/slimbus/core.c b/drivers/slimbus/core.c
index b5d5bbb9fdb6..ab927fd077cb 100644
--- a/drivers/slimbus/core.c
+++ b/drivers/slimbus/core.c
@@ -337,9 +337,9 @@ static bool slim_eaddr_equal(const struct slim_eaddr *a,
 		a->instance == b->instance);
 }
 
-static int slim_match_dev(struct device *dev, void *data)
+static int slim_match_dev(struct device *dev, const void *data)
 {
-	struct slim_eaddr *e_addr = data;
+	const struct slim_eaddr *e_addr = data;
 	struct slim_device *sbdev = to_slim_device(dev);
 
 	return slim_eaddr_equal(&sbdev->e_addr, e_addr);
@@ -385,9 +385,9 @@ struct slim_device *slim_get_device(struct slim_controller *ctrl,
 }
 EXPORT_SYMBOL_GPL(slim_get_device);
 
-static int of_slim_match_dev(struct device *dev, void *data)
+static int of_slim_match_dev(struct device *dev, const void *data)
 {
-	struct device_node *np = data;
+	const struct device_node *np = data;
 	struct slim_device *sbdev = to_slim_device(dev);
 
 	return (sbdev->dev.of_node == np);
diff --git a/drivers/thunderbolt/retimer.c b/drivers/thunderbolt/retimer.c
index 89d2919d0193..21d2902c6102 100644
--- a/drivers/thunderbolt/retimer.c
+++ b/drivers/thunderbolt/retimer.c
@@ -461,7 +461,7 @@ struct tb_retimer_lookup {
 	u8 index;
 };
 
-static int retimer_match(struct device *dev, void *data)
+static int retimer_match(struct device *dev, const void *data)
 {
 	const struct tb_retimer_lookup *lookup = data;
 	struct tb_retimer *rt = tb_to_retimer(dev);
diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index 11a50c86a1e4..b0630e6d9472 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -1026,7 +1026,7 @@ static int remove_missing_service(struct device *dev, void *data)
 	return 0;
 }
 
-static int find_service(struct device *dev, void *data)
+static int find_service(struct device *dev, const void *data)
 {
 	const struct tb_property *p = data;
 	struct tb_service *svc;
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 74fa02b23772..8e0aa2c76d40 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2365,9 +2365,9 @@ struct uart_match {
 	struct uart_driver *driver;
 };
 
-static int serial_match_port(struct device *dev, void *data)
+static int serial_match_port(struct device *dev, const void *data)
 {
-	struct uart_match *match = data;
+	const struct uart_match *match = data;
 	struct tty_driver *tty_drv = match->driver->tty_driver;
 	dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
 		match->port->line;
diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 4b3047e055a3..601a81aa1e10 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -229,10 +229,10 @@ static const char * const usb_modes[] = {
 /* ------------------------------------------------------------------------- */
 /* Alternate Modes */
 
-static int altmode_match(struct device *dev, void *data)
+static int altmode_match(struct device *dev, const void *data)
 {
 	struct typec_altmode *adev = to_typec_altmode(dev);
-	struct typec_device_id *id = data;
+	const struct typec_device_id *id = data;
 
 	if (!is_typec_altmode(dev))
 		return 0;
@@ -1282,7 +1282,7 @@ const struct device_type typec_cable_dev_type = {
 	.release = typec_cable_release,
 };
 
-static int cable_match(struct device *dev, void *data)
+static int cable_match(struct device *dev, const void *data)
 {
 	return is_typec_cable(dev);
 }
@@ -2028,7 +2028,7 @@ const struct device_type typec_port_dev_type = {
 /* --------------------------------------- */
 /* Driver callbacks to report role updates */
 
-static int partner_match(struct device *dev, void *data)
+static int partner_match(struct device *dev, const void *data)
 {
 	return is_typec_partner(dev);
 }
diff --git a/include/linux/device.h b/include/linux/device.h
index 667cb6db9019..0e0bc9bfe0d1 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1081,8 +1081,8 @@ int device_for_each_child_reverse(struct device *dev, void *data,
 int device_for_each_child_reverse_from(struct device *parent,
 				       struct device *from, const void *data,
 				       int (*fn)(struct device *, const void *));
-struct device *device_find_child(struct device *dev, void *data,
-				 int (*match)(struct device *dev, void *data));
+struct device *device_find_child(struct device *dev, const void *data,
+				 device_match_t match);
 struct device *device_find_child_by_name(struct device *parent,
 					 const char *name);
 struct device *device_find_any_child(struct device *parent);
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index bd1243657c01..4d3baf324900 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -497,8 +497,8 @@ extern void iscsi_destroy_all_flashnode(struct Scsi_Host *shost);
 extern int iscsi_flashnode_bus_match(struct device *dev,
 				     const struct device_driver *drv);
 extern struct device *
-iscsi_find_flashnode_sess(struct Scsi_Host *shost, void *data,
-			  int (*fn)(struct device *dev, void *data));
+iscsi_find_flashnode_sess(struct Scsi_Host *shost, const void *data,
+			  device_match_t fn);
 extern struct device *
 iscsi_find_flashnode_conn(struct iscsi_bus_flash_session *fnode_sess);
 
diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 5a7c0e565a89..e827775baf2e 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -1367,7 +1367,7 @@ static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
 	return dsa_switch_parse_ports_of(ds, dn);
 }
 
-static int dev_is_class(struct device *dev, void *class)
+static int dev_is_class(struct device *dev, const void *class)
 {
 	if (dev->class != NULL && !strcmp(dev->class->name, class))
 		return 1;
diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index d0337c11f9ee..cc8948f49117 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -725,7 +725,7 @@ static void default_mock_decoder(struct cxl_decoder *cxld)
 	cxld->reset = mock_decoder_reset;
 }
 
-static int first_decoder(struct device *dev, void *data)
+static int first_decoder(struct device *dev, const void *data)
 {
 	struct cxl_decoder *cxld;
 
-- 
cgit v1.2.3


From d784b43c2d8bf24c2c80ef45ccbc41588945c415 Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Tue, 24 Dec 2024 21:05:04 +0800
Subject: driver core: Simplify API device_find_child_by_name() implementation

Simplify device_find_child_by_name() implementation by both existing
API device_find_child() and device_match_name().

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-5-6623037414d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/core.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index b242993f816d..ee778d380777 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4110,18 +4110,7 @@ EXPORT_SYMBOL_GPL(device_find_child);
 struct device *device_find_child_by_name(struct device *parent,
 					 const char *name)
 {
-	struct klist_iter i;
-	struct device *child;
-
-	if (!parent)
-		return NULL;
-
-	klist_iter_init(&parent->p->klist_children, &i);
-	while ((child = next_device(&i)))
-		if (sysfs_streq(dev_name(child), name) && get_device(child))
-			break;
-	klist_iter_exit(&i);
-	return child;
+	return device_find_child(parent, name, device_match_name);
 }
 EXPORT_SYMBOL_GPL(device_find_child_by_name);
 
-- 
cgit v1.2.3


From 6890fdc856014d731708d684a7c6f9dafec17d60 Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Tue, 24 Dec 2024 21:05:05 +0800
Subject: driver core: Remove match_any()

Static match_any() is now exactly same as API device_match_any().
Remove the former and use the later instead.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-6-6623037414d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/core.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index ee778d380777..6f1b2a1dbbf7 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4114,11 +4114,6 @@ struct device *device_find_child_by_name(struct device *parent,
 }
 EXPORT_SYMBOL_GPL(device_find_child_by_name);
 
-static int match_any(struct device *dev, const void *unused)
-{
-	return 1;
-}
-
 /**
  * device_find_any_child - device iterator for locating a child device, if any.
  * @parent: parent struct device
@@ -4130,7 +4125,7 @@ static int match_any(struct device *dev, const void *unused)
  */
 struct device *device_find_any_child(struct device *parent)
 {
-	return device_find_child(parent, NULL, match_any);
+	return device_find_child(parent, NULL, device_match_any);
 }
 EXPORT_SYMBOL_GPL(device_find_any_child);
 
-- 
cgit v1.2.3


From adf908c965798c33d1148393927a7c0c5d08053c Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Tue, 24 Dec 2024 21:05:08 +0800
Subject: driver core: Introduce an device matching API device_match_type()

Introduce device_match_type() for purposes below:

- Test if a device matches with a specified device type.
- As argument of various device finding APIs to find a device with
  specified type.

device_find_child() will use it to simplify operations later.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-9-6623037414d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/core.c        | 6 ++++++
 include/linux/device/bus.h | 1 +
 2 files changed, 7 insertions(+)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 6f1b2a1dbbf7..d4c20e9b23da 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -5228,6 +5228,12 @@ int device_match_name(struct device *dev, const void *name)
 }
 EXPORT_SYMBOL_GPL(device_match_name);
 
+int device_match_type(struct device *dev, const void *type)
+{
+	return dev->type == type;
+}
+EXPORT_SYMBOL_GPL(device_match_type);
+
 int device_match_of_node(struct device *dev, const void *np)
 {
 	return np && dev->of_node == np;
diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h
index cdc4757217f9..bc3fd74bb763 100644
--- a/include/linux/device/bus.h
+++ b/include/linux/device/bus.h
@@ -131,6 +131,7 @@ typedef int (*device_match_t)(struct device *dev, const void *data);
 
 /* Generic device matching functions that all busses can use to match with */
 int device_match_name(struct device *dev, const void *name);
+int device_match_type(struct device *dev, const void *type);
 int device_match_of_node(struct device *dev, const void *np);
 int device_match_fwnode(struct device *dev, const void *fwnode);
 int device_match_devt(struct device *dev, const void *pdevt);
-- 
cgit v1.2.3


From 3f58ee540d190e9c52b91e055683d15c8ed81112 Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Sun, 5 Jan 2025 16:34:04 +0800
Subject: driver core: Move true expression out of if condition in 3 device
 finding APIs

For bus_find_device(), driver_find_device(), and device_find_child(), all
of their function body have pattern below:

{
	struct klist_iter i;
	struct device *dev;

	...
	while ((dev = next_device(&i)))
		if (match(dev, data) && get_device(dev))
			break;
	...
}

The expression 'get_device(dev)' in the if condition always returns true
since @dev != NULL.

Move the expression to if body to make logic of these APIs more clearer.

Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250105-class_fix-v6-3-3a2f1768d4d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/bus.c    | 7 +++++--
 drivers/base/core.c   | 7 +++++--
 drivers/base/driver.c | 7 +++++--
 3 files changed, 15 insertions(+), 6 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 657c93c38b0d..73a56f376d3a 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -402,9 +402,12 @@ struct device *bus_find_device(const struct bus_type *bus,
 
 	klist_iter_init_node(&sp->klist_devices, &i,
 			     (start ? &start->p->knode_bus : NULL));
-	while ((dev = next_device(&i)))
-		if (match(dev, data) && get_device(dev))
+	while ((dev = next_device(&i))) {
+		if (match(dev, data)) {
+			get_device(dev);
 			break;
+		}
+	}
 	klist_iter_exit(&i);
 	subsys_put(sp);
 	return dev;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index d4c20e9b23da..a83a1350fb5b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4089,9 +4089,12 @@ struct device *device_find_child(struct device *parent, const void *data,
 		return NULL;
 
 	klist_iter_init(&parent->p->klist_children, &i);
-	while ((child = next_device(&i)))
-		if (match(child, data) && get_device(child))
+	while ((child = next_device(&i))) {
+		if (match(child, data)) {
+			get_device(child);
 			break;
+		}
+	}
 	klist_iter_exit(&i);
 	return child;
 }
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index b4eb5b89c4ee..6f033a741aa7 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -160,9 +160,12 @@ struct device *driver_find_device(const struct device_driver *drv,
 
 	klist_iter_init_node(&drv->p->klist_devices, &i,
 			     (start ? &start->p->knode_driver : NULL));
-	while ((dev = next_device(&i)))
-		if (match(dev, data) && get_device(dev))
+	while ((dev = next_device(&i))) {
+		if (match(dev, data)) {
+			get_device(dev);
 			break;
+		}
+	}
 	klist_iter_exit(&i);
 	return dev;
 }
-- 
cgit v1.2.3


From 037116a6cca3e4dbc97905b6e254e8fe7475d502 Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Sun, 5 Jan 2025 16:34:06 +0800
Subject: driver core: Correct parameter check for API
 device_for_each_child_reverse_from()

device_for_each_child_reverse_from() checks (!parent->p) for its
parameter @parent, and that is not consistent with other APIs of
its cluster as shown below:

device_for_each_child_reverse_from() // check (!parent->p)
device_for_each_child_reverse()      // check (!parent || !parent->p)
device_for_each_child()              // same above
device_find_child()                  // same above

Correct the API's parameter @parent check by (!parent || !parent->p).

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250105-class_fix-v6-5-3a2f1768d4d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index a83a1350fb5b..d3800f0dc5bb 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4050,7 +4050,7 @@ int device_for_each_child_reverse_from(struct device *parent,
 	struct device *child;
 	int error = 0;
 
-	if (!parent->p)
+	if (!parent || !parent->p)
 		return 0;
 
 	klist_iter_init_node(&parent->p->klist_children, &i,
-- 
cgit v1.2.3


From 523c6b3ed7702a638e0f8fd02708a7ed4f938269 Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Sun, 5 Jan 2025 16:34:07 +0800
Subject: driver core: Correct API device_for_each_child_reverse_from()
 prototype

For API device_for_each_child_reverse_from(..., const void *data,
		int (*fn)(struct device *dev, const void *data))

- Type of @data is const pointer, and means caller's data @*data is not
  allowed to be modified, but that usually is not proper for such non
  finding device iterating API.

- Types for both @data and @fn are not consistent with all other
  for_each device iterating APIs device_for_each_child(_reverse)(),
  bus_for_each_dev() and (driver|class)_for_each_device().

Correct its prototype by removing const from parameter types, then adapt
for various existing usages.

An dedicated typedef device_iter_t will be introduced as @fn() type for
various for_each device interating APIs later.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250105-class_fix-v6-6-3a2f1768d4d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/core.c       | 4 ++--
 drivers/cxl/core/hdm.c    | 2 +-
 drivers/cxl/core/region.c | 2 +-
 include/linux/device.h    | 4 ++--
 4 files changed, 6 insertions(+), 6 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index d3800f0dc5bb..5ee53b3bca6a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4043,8 +4043,8 @@ EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
  * device_for_each_child_reverse_from();
  */
 int device_for_each_child_reverse_from(struct device *parent,
-				       struct device *from, const void *data,
-				       int (*fn)(struct device *, const void *))
+				       struct device *from, void *data,
+				       int (*fn)(struct device *, void *))
 {
 	struct klist_iter i;
 	struct device *child;
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 28edd5822486..50e6a45b30ba 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -703,7 +703,7 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
 	return 0;
 }
 
-static int commit_reap(struct device *dev, const void *data)
+static int commit_reap(struct device *dev, void *data)
 {
 	struct cxl_port *port = to_cxl_port(dev->parent);
 	struct cxl_decoder *cxld;
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index bfecd71040c2..a4cff4c266e7 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -778,7 +778,7 @@ out:
 	return rc;
 }
 
-static int check_commit_order(struct device *dev, const void *data)
+static int check_commit_order(struct device *dev, void *data)
 {
 	struct cxl_decoder *cxld = to_cxl_decoder(dev);
 
diff --git a/include/linux/device.h b/include/linux/device.h
index a9d928398895..025bac08fca7 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1079,8 +1079,8 @@ int device_for_each_child(struct device *parent, void *data,
 int device_for_each_child_reverse(struct device *parent, void *data,
 				  int (*fn)(struct device *dev, void *data));
 int device_for_each_child_reverse_from(struct device *parent,
-				       struct device *from, const void *data,
-				       int (*fn)(struct device *, const void *));
+				       struct device *from, void *data,
+				       int (*fn)(struct device *, void *));
 struct device *device_find_child(struct device *parent, const void *data,
 				 device_match_t match);
 struct device *device_find_child_by_name(struct device *parent,
-- 
cgit v1.2.3


From 767b74e0d1fc7890a94d1770acf05a442474bd87 Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Sun, 5 Jan 2025 16:34:08 +0800
Subject: driver core: Introduce device_iter_t for device iterating APIs

There are several for_each APIs which has parameter with type below:
int (*fn)(struct device *dev, void *data)
They iterate over various device lists and call @fn() for each device
with caller provided data @*data, and they usually need to modify @*data.

Give the type an dedicated typedef with advantages shown below:
typedef int (*device_iter_t)(struct device *dev, void *data)

- Shorter API declarations and definitions
- Prevent further for_each APIs from using bad parameter type

So introduce device_iter_t and apply it to various existing APIs below:
bus_for_each_dev()
(class|driver)_for_each_device()
device_for_each_child(_reverse|_reverse_from)().

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250105-class_fix-v6-7-3a2f1768d4d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/bus.c            | 2 +-
 drivers/base/class.c          | 2 +-
 drivers/base/core.c           | 6 +++---
 drivers/base/driver.c         | 2 +-
 include/linux/device.h        | 6 +++---
 include/linux/device/bus.h    | 7 +++++--
 include/linux/device/class.h  | 4 ++--
 include/linux/device/driver.h | 2 +-
 8 files changed, 17 insertions(+), 14 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 73a56f376d3a..6b9e65a42cd2 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -354,7 +354,7 @@ static struct device *next_device(struct klist_iter *i)
  * count in the supplied callback.
  */
 int bus_for_each_dev(const struct bus_type *bus, struct device *start,
-		     void *data, int (*fn)(struct device *, void *))
+		     void *data, device_iter_t fn)
 {
 	struct subsys_private *sp = bus_to_subsys(bus);
 	struct klist_iter i;
diff --git a/drivers/base/class.c b/drivers/base/class.c
index d57f277978dc..70ee6a7ba5a3 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -402,7 +402,7 @@ EXPORT_SYMBOL_GPL(class_dev_iter_exit);
  * code.  There's no locking restriction.
  */
 int class_for_each_device(const struct class *class, const struct device *start,
-			  void *data, int (*fn)(struct device *, void *))
+			  void *data, device_iter_t fn)
 {
 	struct subsys_private *sp = class_to_subsys(class);
 	struct class_dev_iter iter;
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 5ee53b3bca6a..7d79a0549ac7 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3980,7 +3980,7 @@ const char *device_get_devnode(const struct device *dev,
  * other than 0, we break out and return that value.
  */
 int device_for_each_child(struct device *parent, void *data,
-			  int (*fn)(struct device *dev, void *data))
+			  device_iter_t fn)
 {
 	struct klist_iter i;
 	struct device *child;
@@ -4010,7 +4010,7 @@ EXPORT_SYMBOL_GPL(device_for_each_child);
  * other than 0, we break out and return that value.
  */
 int device_for_each_child_reverse(struct device *parent, void *data,
-				  int (*fn)(struct device *dev, void *data))
+				  device_iter_t fn)
 {
 	struct klist_iter i;
 	struct device *child;
@@ -4044,7 +4044,7 @@ EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
  */
 int device_for_each_child_reverse_from(struct device *parent,
 				       struct device *from, void *data,
-				       int (*fn)(struct device *, void *))
+				       device_iter_t fn)
 {
 	struct klist_iter i;
 	struct device *child;
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 6f033a741aa7..8ab010ddf709 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -115,7 +115,7 @@ EXPORT_SYMBOL_GPL(driver_set_override);
  * Iterate over the @drv's list of devices calling @fn for each one.
  */
 int driver_for_each_device(struct device_driver *drv, struct device *start,
-			   void *data, int (*fn)(struct device *, void *))
+			   void *data, device_iter_t fn)
 {
 	struct klist_iter i;
 	struct device *dev;
diff --git a/include/linux/device.h b/include/linux/device.h
index 025bac08fca7..36d1a1607712 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1075,12 +1075,12 @@ void device_del(struct device *dev);
 DEFINE_FREE(device_del, struct device *, if (_T) device_del(_T))
 
 int device_for_each_child(struct device *parent, void *data,
-			  int (*fn)(struct device *dev, void *data));
+			  device_iter_t fn);
 int device_for_each_child_reverse(struct device *parent, void *data,
-				  int (*fn)(struct device *dev, void *data));
+				  device_iter_t fn);
 int device_for_each_child_reverse_from(struct device *parent,
 				       struct device *from, void *data,
-				       int (*fn)(struct device *, void *));
+				       device_iter_t fn);
 struct device *device_find_child(struct device *parent, const void *data,
 				 device_match_t match);
 struct device *device_find_child_by_name(struct device *parent,
diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h
index bc3fd74bb763..3d3517da41a1 100644
--- a/include/linux/device/bus.h
+++ b/include/linux/device/bus.h
@@ -139,9 +139,12 @@ int device_match_acpi_dev(struct device *dev, const void *adev);
 int device_match_acpi_handle(struct device *dev, const void *handle);
 int device_match_any(struct device *dev, const void *unused);
 
+/* Device iterating function type for various driver core for_each APIs */
+typedef int (*device_iter_t)(struct device *dev, void *data);
+
 /* iterator helpers for buses */
-int bus_for_each_dev(const struct bus_type *bus, struct device *start, void *data,
-		     int (*fn)(struct device *dev, void *data));
+int bus_for_each_dev(const struct bus_type *bus, struct device *start,
+		     void *data, device_iter_t fn);
 struct device *bus_find_device(const struct bus_type *bus, struct device *start,
 			       const void *data, device_match_t match);
 /**
diff --git a/include/linux/device/class.h b/include/linux/device/class.h
index 518c9c83d64b..aa67d4736816 100644
--- a/include/linux/device/class.h
+++ b/include/linux/device/class.h
@@ -92,8 +92,8 @@ void class_dev_iter_init(struct class_dev_iter *iter, const struct class *class,
 struct device *class_dev_iter_next(struct class_dev_iter *iter);
 void class_dev_iter_exit(struct class_dev_iter *iter);
 
-int class_for_each_device(const struct class *class, const struct device *start, void *data,
-			  int (*fn)(struct device *dev, void *data));
+int class_for_each_device(const struct class *class, const struct device *start,
+			  void *data, device_iter_t fn);
 struct device *class_find_device(const struct class *class, const struct device *start,
 				 const void *data, device_match_t match);
 
diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index 5c04b8e3833b..cd8e0f0a634b 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -154,7 +154,7 @@ void driver_remove_file(const struct device_driver *driver,
 int driver_set_override(struct device *dev, const char **override,
 			const char *s, size_t len);
 int __must_check driver_for_each_device(struct device_driver *drv, struct device *start,
-					void *data, int (*fn)(struct device *dev, void *));
+					void *data, device_iter_t fn);
 struct device *driver_find_device(const struct device_driver *drv,
 				  struct device *start, const void *data,
 				  device_match_t match);
-- 
cgit v1.2.3


From 51796f5e2960130fe53e9a71d07152622d5e024c Mon Sep 17 00:00:00 2001
From: Zijun Hu <quic_zijuhu@quicinc.com>
Date: Sun, 5 Jan 2025 16:34:09 +0800
Subject: driver core: Move two simple APIs for finding child device to header

The following two APIs are for finding child device, and both only have
one line code in function body.
device_find_child_by_name()
device_find_any_child()

Move them to header as static inline function.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250105-class_fix-v6-8-3a2f1768d4d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/core.c    | 32 --------------------------------
 include/linux/device.h | 32 +++++++++++++++++++++++++++++---
 2 files changed, 29 insertions(+), 35 deletions(-)

(limited to 'drivers/base/core.c')

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 7d79a0549ac7..5a1f05198114 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4100,38 +4100,6 @@ struct device *device_find_child(struct device *parent, const void *data,
 }
 EXPORT_SYMBOL_GPL(device_find_child);
 
-/**
- * device_find_child_by_name - device iterator for locating a child device.
- * @parent: parent struct device
- * @name: name of the child device
- *
- * This is similar to the device_find_child() function above, but it
- * returns a reference to a device that has the name @name.
- *
- * NOTE: you will need to drop the reference with put_device() after use.
- */
-struct device *device_find_child_by_name(struct device *parent,
-					 const char *name)
-{
-	return device_find_child(parent, name, device_match_name);
-}
-EXPORT_SYMBOL_GPL(device_find_child_by_name);
-
-/**
- * device_find_any_child - device iterator for locating a child device, if any.
- * @parent: parent struct device
- *
- * This is similar to the device_find_child() function above, but it
- * returns a reference to a child device, if any.
- *
- * NOTE: you will need to drop the reference with put_device() after use.
- */
-struct device *device_find_any_child(struct device *parent)
-{
-	return device_find_child(parent, NULL, device_match_any);
-}
-EXPORT_SYMBOL_GPL(device_find_any_child);
-
 int __init devices_init(void)
 {
 	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
diff --git a/include/linux/device.h b/include/linux/device.h
index 36d1a1607712..1e9aded9a086 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1083,9 +1083,35 @@ int device_for_each_child_reverse_from(struct device *parent,
 				       device_iter_t fn);
 struct device *device_find_child(struct device *parent, const void *data,
 				 device_match_t match);
-struct device *device_find_child_by_name(struct device *parent,
-					 const char *name);
-struct device *device_find_any_child(struct device *parent);
+/**
+ * device_find_child_by_name - device iterator for locating a child device.
+ * @parent: parent struct device
+ * @name: name of the child device
+ *
+ * This is similar to the device_find_child() function above, but it
+ * returns a reference to a device that has the name @name.
+ *
+ * NOTE: you will need to drop the reference with put_device() after use.
+ */
+static inline struct device *device_find_child_by_name(struct device *parent,
+						       const char *name)
+{
+	return device_find_child(parent, name, device_match_name);
+}
+
+/**
+ * device_find_any_child - device iterator for locating a child device, if any.
+ * @parent: parent struct device
+ *
+ * This is similar to the device_find_child() function above, but it
+ * returns a reference to a child device, if any.
+ *
+ * NOTE: you will need to drop the reference with put_device() after use.
+ */
+static inline struct device *device_find_any_child(struct device *parent)
+{
+	return device_find_child(parent, NULL, device_match_any);
+}
 
 int device_rename(struct device *dev, const char *new_name);
 int device_move(struct device *dev, struct device *new_parent,
-- 
cgit v1.2.3