This patch series is to 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); Why to constify the API? - 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 matching functions can be directly taken as the API's argument, they were exported by driver core. How to constify the API? - Now, no (@match)() argument of the API usages is modifying its match data @*data after previous cleanup, so it is easy and safe to make its parameter @data take const void * as type. - Simplify involved codes further if it is possbile with benefits brought by constifying the API. Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx> --- Changes in v2: - Series v1 have no code review comments and are posted a long time ago, so may ignore differences. - Link to v1: https://lore.kernel.org/r/20240811-const_dfc_done-v1-0-9d85e3f943cb@xxxxxxxxxxx - Motivation link: https://lore.kernel.org/lkml/917359cc-a421-41dd-93f4-d28937fe2325@xxxxxxxxxx --- Zijun Hu (32): driver core: Constify API device_find_child() driver core: Introduce device_match_type() to match device with a device type drm/mediatek: Adapt for constified device_find_child() hwmon: Adapt for constified device_find_child() media: pci: mgb4: Adapt for constified device_find_child() thunderbolt: Adapt for constified device_find_child() gpio: sim: Remove gpio_sim_dev_match_fwnode() net: dsa: Adapt for constified device_find_child() pwm: Adapt for constified device_find_child() nvdimm: Adapt for constified device_find_child() libnvdimm: Simplify nd_namespace_store() implementation firewire: core: Adapt for constified device_find_child() serial: core: Adapt for constified device_find_child() usb: typec: class: Remove both cable_match() and partner_match() usb: typec: class: Adapt for constified device_find_child() slimbus: core: Simplify of_find_slim_device() implementation slimbus: core: Constify slim_eaddr_equal() slimbus: core: Adapt for constified device_find_child() scsi: iscsi: Constify API iscsi_find_flashnode_sess() scsi: qla4xxx: Adapt for constified iscsi_find_flashnode_sess() scsi: iscsi: Adapt for constified device_find_child() cxl/region: Adapt for constified device_find_child() cxl/pmem: Remove match_nvdimm_bridge() cxl/core/pci: Adapt for constified device_find_child() cxl/test: Adapt for constified device_find_child() sparc: vio: Adapt for constified device_find_child() bus: fsl-mc: Adapt for constified device_find_child() block: sunvdc: Adapt for constified device_find_child() firmware: arm_scmi: Adapt for constified device_find_child() efi: dev-path-parser: Adapt for constified device_find_child() rpmsg: core: Adapt for constified device_find_child() driver core: Simplify API device_find_child_by_name() implementation arch/sparc/kernel/vio.c | 6 +++--- drivers/base/core.c | 30 ++++++++++-------------------- drivers/block/sunvdc.c | 6 +++--- drivers/bus/fsl-mc/dprc-driver.c | 6 +++--- drivers/cxl/core/pci.c | 4 ++-- drivers/cxl/core/pmem.c | 9 +++------ 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 | 7 +------ 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/nvdimm/claim.c | 9 +-------- 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 | 17 +++++------------ drivers/thunderbolt/retimer.c | 2 +- drivers/thunderbolt/xdomain.c | 2 +- drivers/tty/serial/serial_core.c | 4 ++-- drivers/usb/typec/class.c | 31 ++++++++++++++----------------- include/linux/device.h | 4 ++-- include/linux/device/bus.h | 1 + include/scsi/scsi_transport_iscsi.h | 4 ++-- net/dsa/dsa.c | 2 +- tools/testing/cxl/test/cxl.c | 2 +- 30 files changed, 89 insertions(+), 119 deletions(-) --- base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37 change-id: 20241201-const_dfc_done-aaec71e3bbea Best regards, -- Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
