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>

6 files changed, 12 insertions, 12 deletions

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 78b96cd63de9..dd68b8191a0a 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -80,11 +80,11 @@ static phys_addr_t mc_portal_base_phys_addr;
  *
  * Returns 1 on success, 0 otherwise.
  */
-static int fsl_mc_bus_match(struct device *dev, struct device_driver *drv)
+static int fsl_mc_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	const struct fsl_mc_device_id *id;
 	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
-	struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(drv);
+	const struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(drv);
 	bool found = false;
 
 	/* When driver_override is set, only bind to the matching driver */
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index f8f674adf1d4..b193c2d25621 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -1694,10 +1694,10 @@ static int mhi_ep_uevent(const struct device *dev, struct kobj_uevent_env *env)
 					mhi_dev->name);
 }
 
-static int mhi_ep_match(struct device *dev, struct device_driver *drv)
+static int mhi_ep_match(struct device *dev, const struct device_driver *drv)
 {
 	struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev);
-	struct mhi_ep_driver *mhi_drv = to_mhi_ep_driver(drv);
+	const struct mhi_ep_driver *mhi_drv = to_mhi_ep_driver(drv);
 	const struct mhi_device_id *id;
 
 	/*
diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index 173f79918741..ce7d2e62c2f1 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -1442,10 +1442,10 @@ static int mhi_uevent(const struct device *dev, struct kobj_uevent_env *env)
 					mhi_dev->name);
 }
 
-static int mhi_match(struct device *dev, struct device_driver *drv)
+static int mhi_match(struct device *dev, const struct device_driver *drv)
 {
 	struct mhi_device *mhi_dev = to_mhi_device(dev);
-	struct mhi_driver *mhi_drv = to_mhi_driver(drv);
+	const struct mhi_driver *mhi_drv = to_mhi_driver(drv);
 	const struct mhi_device_id *id;
 
 	/*
diff --git a/drivers/bus/mips_cdmm.c b/drivers/bus/mips_cdmm.c
index 8baf14bd5eff..12dd32fd0b62 100644
--- a/drivers/bus/mips_cdmm.c
+++ b/drivers/bus/mips_cdmm.c
@@ -37,7 +37,7 @@
 /* Each block of device registers is 64 bytes */
 #define CDMM_DRB_SIZE		64
 
-#define to_mips_cdmm_driver(d)	container_of(d, struct mips_cdmm_driver, drv)
+#define to_mips_cdmm_driver(d)	container_of_const(d, struct mips_cdmm_driver, drv)
 
 /* Default physical base address */
 static phys_addr_t mips_cdmm_default_base;
@@ -59,10 +59,10 @@ mips_cdmm_lookup(const struct mips_cdmm_device_id *table,
 	return ret ? table : NULL;
 }
 
-static int mips_cdmm_match(struct device *dev, struct device_driver *drv)
+static int mips_cdmm_match(struct device *dev, const struct device_driver *drv)
 {
 	struct mips_cdmm_device *cdev = to_mips_cdmm_device(dev);
-	struct mips_cdmm_driver *cdrv = to_mips_cdmm_driver(drv);
+	const struct mips_cdmm_driver *cdrv = to_mips_cdmm_driver(drv);
 
 	return mips_cdmm_lookup(cdrv->id_table, cdev) != NULL;
 }
diff --git a/drivers/bus/moxtet.c b/drivers/bus/moxtet.c
index 641c1a6adc8a..8412406c4f1d 100644
--- a/drivers/bus/moxtet.c
+++ b/drivers/bus/moxtet.c
@@ -83,10 +83,10 @@ static const struct attribute_group *moxtet_dev_groups[] = {
 	NULL,
 };
 
-static int moxtet_match(struct device *dev, struct device_driver *drv)
+static int moxtet_match(struct device *dev, const struct device_driver *drv)
 {
 	struct moxtet_device *mdev = to_moxtet_device(dev);
-	struct moxtet_driver *tdrv = to_moxtet_driver(drv);
+	const struct moxtet_driver *tdrv = to_moxtet_driver(drv);
 	const enum turris_mox_module_id *t;
 
 	if (of_driver_match_device(dev, drv))
diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c
index 1e29ba76615d..a2a7576a33cc 100644
--- a/drivers/bus/sunxi-rsb.c
+++ b/drivers/bus/sunxi-rsb.c
@@ -130,7 +130,7 @@ struct sunxi_rsb {
 /* bus / slave device related functions */
 static const struct bus_type sunxi_rsb_bus;
 
-static int sunxi_rsb_device_match(struct device *dev, struct device_driver *drv)
+static int sunxi_rsb_device_match(struct device *dev, const struct device_driver *drv)
 {
 	return of_driver_match_device(dev, drv);
 }