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

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 <[email protected]>
Reviewed-by: Alex Elder <[email protected]>
Acked-by: Sumit Garg <[email protected]>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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driver core: mark remaining local bus_type variables as const

Now that the driver core can properly handle constant struct bus_type,
change the local driver core bus_type variables to be a constant

driver core: mark remaining local bus_type variables as const

Now that the driver core can properly handle constant struct bus_type,
change the local driver core bus_type variables to be a constant
structure as well, placing them into read-only memory which can not be
modified at runtime.

Cc: Ira Weiny <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Kevin Hilman <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: Len Brown <[email protected]>
Acked-by: William Breathitt Gray <[email protected]>
Acked-by: Dave Ertman <[email protected]>
Link: https://lore.kernel.org/r/2023121908-paver-follow-cc21@gregkh
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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isa: Remove unnecessary checks

The isa_dev->dev.platform_data is initialized with incoming
parameter isa_driver. After it isa_dev->dev.platform_data is
checked for NULL, but incoming parameter isa_d

isa: Remove unnecessary checks

The isa_dev->dev.platform_data is initialized with incoming
parameter isa_driver. After it isa_dev->dev.platform_data is
checked for NULL, but incoming parameter isa_driver is not
NULL since it is dereferenced many times before this check.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Vladislav Efanov <[email protected]>
Acked-by: William Breathitt Gray <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long last

bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <[email protected]> (For fpga)
Reviewed-by: Mathieu Poirier <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <[email protected]> (For ARM, Amba and related parts)
Acked-by: Mark Brown <[email protected]>
Acked-by: Chen-Yu Tsai <[email protected]> (for sunxi-rsb)
Acked-by: Pali Rohár <[email protected]>
Acked-by: Mauro Carvalho Chehab <[email protected]> (for media)
Acked-by: Hans de Goede <[email protected]> (For drivers/platform)
Acked-by: Alexandre Belloni <[email protected]>
Acked-By: Vinod Koul <[email protected]>
Acked-by: Juergen Gross <[email protected]> (For xen)
Acked-by: Lee Jones <[email protected]> (For mfd)
Acked-by: Johannes Thumshirn <[email protected]> (For mcb)
Acked-by: Johan Hovold <[email protected]>
Acked-by: Srinivas Kandagatla <[email protected]> (For slimbus)
Acked-by: Kirti Wankhede <[email protected]> (For vfio)
Acked-by: Maximilian Luz <[email protected]>
Acked-by: Heikki Krogerus <[email protected]> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <[email protected]> (For ipack)
Acked-by: Geoff Levand <[email protected]> (For ps3)
Acked-by: Yehezkel Bernat <[email protected]> (For thunderbolt)
Acked-by: Alexander Shishkin <[email protected]> (For intel_th)
Acked-by: Dominik Brodowski <[email protected]> (For pcmcia)
Acked-by: Rafael J. Wysocki <[email protected]> (For ACPI)
Acked-by: Bjorn Andersson <[email protected]> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <[email protected]> (For intel-ish-hid)
Acked-by: Dan Williams <[email protected]> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <[email protected]> (For isa)
Acked-by: Stefan Richter <[email protected]> (For firewire)
Acked-by: Benjamin Tissoires <[email protected]> (For hid)
Acked-by: Thorsten Scherer <[email protected]> (For siox)
Acked-by: Sven Van Asbroeck <[email protected]> (For anybuss)
Acked-by: Ulf Hansson <[email protected]> (For MMC)
Acked-by: Wolfram Sang <[email protected]> # for I2C
Acked-by: Sudeep Holla <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Acked-by: Dmitry Torokhov <[email protected]>
Acked-by: Finn Thain <[email protected]>
Signed-off-by: Uwe Kleine-König <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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isa: Make the remove callback for isa drivers return void

The driver core ignores the return value of the remove callback, so
don't give isa drivers the chance to provide a value.

Adapt all isa_dri

isa: Make the remove callback for isa drivers return void

The driver core ignores the return value of the remove callback, so
don't give isa drivers the chance to provide a value.

Adapt all isa_drivers with a remove callbacks accordingly; they all
return 0 unconditionally anyhow.

Acked-by: Marc Kleine-Budde <[email protected]> # for drivers/net/can/sja1000/tscan1.c
Acked-by: William Breathitt Gray <[email protected]>
Acked-by: Wolfram Sang <[email protected]> # for drivers/i2c/
Reviewed-by: Takashi Iway <[email protected]> # for sound/
Reviewed-by: Hans Verkuil <[email protected]> # for drivers/media/
Signed-off-by: Uwe Kleine-König <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>

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driver core: add SPDX identifiers to all driver core files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the driver core fi

driver core: add SPDX identifiers to all driver core files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the driver core files files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Johannes Berg <[email protected]>
Cc: "Luis R. Rodriguez" <[email protected]>
Cc: William Breathitt Gray <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Kate Stewart <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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isa: Prevent NULL dereference in isa_bus driver callbacks

The isa_driver structure for an isa_bus device is stored in the device
platform_data member of the respective device structure. This
platfor

isa: Prevent NULL dereference in isa_bus driver callbacks

The isa_driver structure for an isa_bus device is stored in the device
platform_data member of the respective device structure. This
platform_data member may be reset to NULL if isa_driver match callback
for the device fails, indicating a device unsupported by the ISA driver.

This patch fixes a possible NULL pointer dereference if one of the
isa_driver callbacks to attempted for an unsupported device. This error
should not occur in practice since ISA devices are typically manually
configured and loaded by the users, but we may as well prevent this
error from popping up for the 0day testers.

Fixes: a5117ba7da37 ("[PATCH] Driver model: add ISA bus")
Signed-off-by: William Breathitt Gray <[email protected]>
Cc: stable <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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isa: Call isa_bus_init before dependent ISA bus drivers register

The isa_bus_init function must be called before drivers which utilize
the ISA bus driver are registered. A race condition for initili

isa: Call isa_bus_init before dependent ISA bus drivers register

The isa_bus_init function must be called before drivers which utilize
the ISA bus driver are registered. A race condition for initilization
exists if device_initcall is used (the isa_bus_init callback is placed
in the same initcall level as dependent drivers which use module_init).
This patch ensures that isa_bus_init is called first by utilizing
postcore_initcall in favor of device_initcall.

Fixes: a5117ba7da37 ("[PATCH] Driver model: add ISA bus")
Cc: Rene Herman <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24)

Replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24)

Signed-off-by: Yang Hongyang<[email protected]>
Signed-off-by: Andrew

dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24)

Replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24)

Signed-off-by: Yang Hongyang<[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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driver core: struct device - replace bus_id with dev_name(), dev_set_name()

Signed-off-by: Kay Sievers <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

isa: set 24-bit dma_mask for ISA devices

dma_alloc_coherent() on x86 currently takes a passed in NULL device
pointer to mean that it should allocate an ISA compatible (24-bit) buffer
which is a bit

isa: set 24-bit dma_mask for ISA devices

dma_alloc_coherent() on x86 currently takes a passed in NULL device
pointer to mean that it should allocate an ISA compatible (24-bit) buffer
which is a bit of a hack.

The ALSA ISA drivers are the main consumers of this but have a struct
device in fact readily available.

For the legacy drivers, this sets the device dma_mask in preparation for
using the actual device with the DMA API so as to eventually not need the
NULL hack in dma_alloc_coherent().

This does not fix a current bug -- 2.6.26-rc1 stumbled over the NULL hack
in dma_alloc_coherent() but this has already been fixed in commit
4a367f3a9dbf2e7ffcee4702203479809236ee6e by Takashi Iwai.

Signed-off-by: Rene Herman <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Acked-by: Takashi Iwai <[email protected]>
Cc: Alan Cox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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[PATCH] Driver model: add ISA bus

During the recent "isa drivers using platform devices" discussion it was
pointed out that (ALSA) ISA drivers ran into the problem of not having
the option to fail d

[PATCH] Driver model: add ISA bus

During the recent "isa drivers using platform devices" discussion it was
pointed out that (ALSA) ISA drivers ran into the problem of not having
the option to fail driver load (device registration rather) upon not
finding their hardware due to a probe() error not being passed up
through the driver model. In the course of that, I suggested a seperate
ISA bus might be best; Russell King agreed and suggested this bus could
use the .match() method for the actual device discovery.

The attached does this. For this old non (generically) discoverable ISA
hardware only the driver itself can do discovery so as a difference with
the platform_bus, this isa_bus also distributes match() up to the driver.

As another difference: these devices only exist in the driver model due
to the driver creating them because it might want to drive them, meaning
that all device creation has been made internal as well.

The usage model this provides is nice, and has been acked from the ALSA
side by Takashi Iwai and Jaroslav Kysela. The ALSA driver module_init's
now (for oldisa-only drivers) become:

static int __init alsa_card_foo_init(void)
{
return isa_register_driver(&snd_foo_isa_driver, SNDRV_CARDS);
}

static void __exit alsa_card_foo_exit(void)
{
isa_unregister_driver(&snd_foo_isa_driver);
}

Quite like the other bus models therefore. This removes a lot of
duplicated init code from the ALSA ISA drivers.

The passed in isa_driver struct is the regular driver struct embedding a
struct device_driver, the normal probe/remove/shutdown/suspend/resume
callbacks, and as indicated that .match callback.

The "SNDRV_CARDS" you see being passed in is a "unsigned int ndev"
parameter, indicating how many devices to create and call our methods with.

The platform_driver callbacks are called with a platform_device param;
the isa_driver callbacks are being called with a "struct device *dev,
unsigned int id" pair directly -- with the device creation completely
internal to the bus it's much cleaner to not leak isa_dev's by passing
them in at all. The id is the only thing we ever want other then the
struct device * anyways, and it makes for nicer code in the callbacks as
well.

With this additional .match() callback ISA drivers have all options. If
ALSA would want to keep the old non-load behaviour, it could stick all
of the old .probe in .match, which would only keep them registered after
everything was found to be present and accounted for. If it wanted the
behaviour of always loading as it inadvertently did for a bit after the
changeover to platform devices, it could just not provide a .match() and
do everything in .probe() as before.

If it, as Takashi Iwai already suggested earlier as a way of following
the model from saner buses more closely, wants to load when a later bind
could conceivably succeed, it could use .match() for the prerequisites
(such as checking the user wants the card enabled and that port/irq/dma
values have been passed in) and .probe() for everything else. This is
the nicest model.

To the code...

This exports only two functions; isa_{,un}register_driver().

isa_register_driver() register's the struct device_driver, and then
loops over the passed in ndev creating devices and registering them.
This causes the bus match method to be called for them, which is:

int isa_bus_match(struct device *dev, struct device_driver *driver)
{
struct isa_driver *isa_driver = to_isa_driver(driver);

if (dev->platform_data == isa_driver) {
if (!isa_driver->match ||
isa_driver->match(dev, to_isa_dev(dev)->id))
return 1;
dev->platform_data = NULL;
}
return 0;
}

The first thing this does is check if this device is in fact one of this
driver's devices by seeing if the device's platform_data pointer is set
to this driver. Platform devices compare strings, but we don't need to
do that with everything being internal, so isa_register_driver() abuses
dev->platform_data as a isa_driver pointer which we can then check here.
I believe platform_data is available for this, but if rather not, moving
the isa_driver pointer to the private struct isa_dev is ofcourse fine as
well.

Then, if the the driver did not provide a .match, it matches. If it did,
the driver match() method is called to determine a match.

If it did _not_ match, dev->platform_data is reset to indicate this to
isa_register_driver which can then unregister the device again.

If during all this, there's any error, or no devices matched at all
everything is backed out again and the error, or -ENODEV, is returned.

isa_unregister_driver() just unregisters the matched devices and the
driver itself.

More global points/questions...

- I'm introducing include/linux/isa.h. It was available but is ofcourse
a somewhat generic name. Moving more isa stuff over to it in time is
ofcourse fine, so can I have it please? :)

- I'm using device_initcall() and added the isa.o (dependent on
CONFIG_ISA) after the base driver model things in the Makefile. Will
this do, or I really need to stick it in drivers/base/init.c, inside
#ifdef CONFIG_ISA? It's working fine.

Lastly -- I also looked, a bit, into integrating with PnP. "Old ISA"
could be another pnp_protocol, but this does not seem to be a good
match, largely due to the same reason platform_devices weren't -- the
devices do not have a life of their own outside the driver, meaning the
pnp_protocol {get,set}_resources callbacks would need to callback into
driver -- which again means you first need to _have_ that driver. Even
if there's clean way around that, you only end up inventing fake but
valid-form PnP IDs and generally catering to the PnP layer without any
practical advantages over this very simple isa_bus. The thing I also
suggested earlier about the user echoing values into /sys to set up the
hardware from userspace first is... well, cute, but a horrible idea from
a user standpoint.

Comments ofcourse appreciated. Hope it's okay. As said, the usage model
is nice at least.

Signed-off-by: Rene Herman <[email protected]>

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