The data mbmer in fw_node structure is an opaque pointer, while nowadays
it is just used to refer to fw_device associated with the fw_node.
This commit redefines the opaque pointer to a pointer to fw_device
structure, and adds some helper functions to set/get it.
Link: https://lore.kernel.org/r/20250908012108.514698-5-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
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>
When detecting updates of bus topology, the data of fw_device is newly
allocated and caches the content of configuration ROM from the
corresponding node. Then, the tree of device is sought to find the
previous data of fw_device corresponding to the node. If found, the
previous data is updated and reused and the data of fw_device newly
allocated is going to be released.
The above procedure is done in the call of device_find_child(), however it
is a bit abusing against the intention of the helper function, since it is
preferable to find only without updating.
This commit splits the update outside of the call.
Cc: Zijun Hu <zijun_hu@icloud.com>
Link: https://lore.kernel.org/r/20240820132132.28839-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In core function, the instances of fw_device corresponding to firewire device
node in system are maintained by IDR. As of kernel v6.0, IDR has been
superseded by XArray and deprecated.
This commit replaces the usage of IDR with XArray to maintain the device
instances. The instance of XArray is allocated statically, and
initialized with XA_FLAGS_ALLOC so that the index of allocated entry starts
with zero and available as the minor identifier of device node.
Link: https://lore.kernel.org/r/20240812014251.165492-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
The core function maintains the instance of fw_device structure by IDR.
The concurrent access to IDR is protected by static read/write semaphore.
The semaphore is also utilized to protect concurrent access to the
content of configuration ROM cached to the instance so that the cache is
swapped to the latest one.
This commit uses guard macro to maintain the mutex.
Link: https://lore.kernel.org/r/20240805085408.251763-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
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>
In the case of firewire core function, the caller of show functions for
device attributes is not only sysfs user, but also device initialization.
This commit adds memo about it against the typical assumption that the
functions are just dedicated to sysfs user.
Link: https://lore.kernel.org/lkml/20240318091759.678326-1-o-takashi@sakamocchi.jp/
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Per filesystems/sysfs.rst, show() should only use sysfs_emit()
or sysfs_emit_at() when formatting the value to be returned to user space.
coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().
> drivers/firewire/core-device.c:326:8-16: WARNING: please use sysfs_emit or sysfs_emit_at
No functional change intended
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Link: https://lore.kernel.org/r/20240122053942.80648-2-lizhijian@fujitsu.com
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
As the last part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when
constructing modalias for unit device. The change brings loss of backward
compatibility since it can fill model field ('mo') which is 0 at current
implementation in the case. However, we can be optimistic against
regression for unit drivers in kernel, due to some points:
1. ALSA drivers for audio and music units use the model fields to match
device, however all of supported devices does not have such legacy
layout.
2. the other unit drivers (e.g. sbp2) does not use the model field to
match device.
The rest of concern is user space application. The most of applications
just take care of node device and does not use the modalias of unit
device, thus the change does not affect to them. But systemd project is
known to get affects from the change since it includes hwdb to take udev
to configure fw character device conveniently. I have a plan to work for
systemd so that the access permission of character device could be kept
across the change.
Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-9-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model_name'
attribute appears in node device, however it is probable to see the other
types of descriptor leaf if the vendor directory includes.
Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-8-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model' attribute
appears in node device, however it is probable to see the other types of
immediate values if the vendor directory includes.
Suggested-by: Adam Goldman <adamg@pobox.com>
Link: https://lore.kernel.org/r/20231221134849.603857-7-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
In IEEE 1394 specification, the size of bus information block of
configuration ROM is fixed to 5, thus the offset of root directory is 5.
Current implementation to handle device structures has the hard-coded
offset.
This commit replaces the offset with macro.
Link: https://lore.kernel.org/r/20231221134849.603857-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Takashi Sakamoto
Zijun Hu
Greg Kroah-Hartman
Li Zhijian