driver core: have match() callback in struct bus_type take a const *

In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *.  This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly.  This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 7 insertions, 7 deletions

diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c
index 2f557e90f2eb..62b0b8b919aa 100644
--- a/drivers/firmware/arm_ffa/bus.c
+++ b/drivers/firmware/arm_ffa/bus.c
@@ -19,7 +19,7 @@
 
 static DEFINE_IDA(ffa_bus_id);
 
-static int ffa_device_match(struct device *dev, struct device_driver *drv)
+static int ffa_device_match(struct device *dev, const struct device_driver *drv)
 {
 	const struct ffa_device_id *id_table;
 	struct ffa_device *ffa_dev;
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 77c78be6e79c..96b2e5f9a8ef 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -207,7 +207,7 @@ scmi_protocol_table_unregister(const struct scmi_device_id *id_table)
 }
 
 static const struct scmi_device_id *
-scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
+scmi_dev_match_id(struct scmi_device *scmi_dev, const struct scmi_driver *scmi_drv)
 {
 	const struct scmi_device_id *id = scmi_drv->id_table;
 
@@ -225,9 +225,9 @@ scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
 	return NULL;
 }
 
-static int scmi_dev_match(struct device *dev, struct device_driver *drv)
+static int scmi_dev_match(struct device *dev, const struct device_driver *drv)
 {
-	struct scmi_driver *scmi_drv = to_scmi_driver(drv);
+	const struct scmi_driver *scmi_drv = to_scmi_driver(drv);
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
 	const struct scmi_device_id *id;
 
diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c
index fa7752f6e89b..c179c4e85108 100644
--- a/drivers/firmware/google/coreboot_table.c
+++ b/drivers/firmware/google/coreboot_table.c
@@ -22,12 +22,12 @@
 #include "coreboot_table.h"
 
 #define CB_DEV(d) container_of(d, struct coreboot_device, dev)
-#define CB_DRV(d) container_of(d, struct coreboot_driver, drv)
+#define CB_DRV(d) container_of_const(d, struct coreboot_driver, drv)
 
-static int coreboot_bus_match(struct device *dev, struct device_driver *drv)
+static int coreboot_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct coreboot_device *device = CB_DEV(dev);
-	struct coreboot_driver *driver = CB_DRV(drv);
+	const struct coreboot_driver *driver = CB_DRV(drv);
 	const struct coreboot_device_id *id;
 
 	if (!driver->id_table)