There are several drivers/base APIs for finding a specific device, and
they currently use the following good type for the @match parameter:
int (*match)(struct device *dev, const void *data)
Since these operations do not modify the caller-provided @*data, this
type is worthy of a dedicated typedef:
typedef int (*device_match_t)(struct device *dev, const void *data)
Advantages of using device_match_t:
- Shorter API declarations and definitions
- Prevent further APIs from using a bad type for @match
So introduce device_match_t and apply it to the existing
(bus|class|driver|auxiliary)_find_device() APIs.
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240813-dev_match_api-v3-1-6c6878a99b9f@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core updates from Greg KH:
"Here is the big set of driver core changes for 6.11-rc1.
Lots of stuff in here, with not a huge diffstat, but apis are evolving
which required lots of files to be touched. Highlights of the changes
in here are:
- platform remove callback api final fixups (Uwe took many releases
to get here, finally!)
- Rust bindings for basic firmware apis and initial driver-core
interactions.
It's not all that useful for a "write a whole driver in rust" type
of thing, but the firmware bindings do help out the phy rust
drivers, and the driver core bindings give a solid base on which
others can start their work.
There is still a long way to go here before we have a multitude of
rust drivers being added, but it's a great first step.
- driver core const api changes.
This reached across all bus types, and there are some fix-ups for
some not-common bus types that linux-next and 0-day testing shook
out.
This work is being done to help make the rust bindings more safe,
as well as the C code, moving toward the end-goal of allowing us to
put driver structures into read-only memory. We aren't there yet,
but are getting closer.
- minor devres cleanups and fixes found by code inspection
- arch_topology minor changes
- other minor driver core cleanups
All of these have been in linux-next for a very long time with no
reported problems"
* tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
ARM: sa1100: make match function take a const pointer
sysfs/cpu: Make crash_hotplug attribute world-readable
dio: Have dio_bus_match() callback take a const *
zorro: make match function take a const pointer
driver core: module: make module_[add|remove]_driver take a const *
driver core: make driver_find_device() take a const *
driver core: make driver_[create|remove]_file take a const *
firmware_loader: fix soundness issue in `request_internal`
firmware_loader: annotate doctests as `no_run`
devres: Correct code style for functions that return a pointer type
devres: Initialize an uninitialized struct member
devres: Fix memory leakage caused by driver API devm_free_percpu()
devres: Fix devm_krealloc() wasting memory
driver core: platform: Switch to use kmemdup_array()
driver core: have match() callback in struct bus_type take a const *
MAINTAINERS: add Rust device abstractions to DRIVER CORE
device: rust: improve safety comments
MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer
MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER
firmware: rust: improve safety comments
...
PCI subfunctions (SF) are anchored on the auxiliary bus. PCI physical
and virtual functions are anchored on the PCI bus. The irq information
of each such function is visible to users via sysfs directory "msi_irqs"
containing files for each irq entry. However, for PCI SFs such
information is unavailable. Due to this users have no visibility on IRQs
used by the SFs.
Secondly, an SF can be multi function device supporting rdma, netdevice
and more. Without irq information at the bus level, the user is unable
to view or use the affinity of the SF IRQs.
Hence to match to the equivalent PCI PFs and VFs, add "irqs" directory,
for supporting auxiliary devices, containing file for each irq entry.
For example:
$ ls /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/
50 51 52 53 54 55 56 57 58
Cc: Simon Horman <horms@kernel.org>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
v9-v10:
- remove Przemek RB
- add name field to auxiliary_irq_info (Greg and Przemek)
- handle bogus IRQ in auxiliary_device_sysfs_irq_remove (Greg)
v8-v9:
- add Przemek RB
- use guard() in auxiliary_irq_dir_prepare (Paolo)
v7-v8:
- use cleanup.h for info and name fields (Greg)
- correct error flow in auxiliary_irq_dir_prepare (Przemek)
- add documentation for new fields of auxiliary_device (Simon)
v6-v7:
- dynamically creating irqs directory when first irq file created (Greg)
- removed irqs flag and simplified the dev_add() API (Greg)
- move sysfs related new code to a new auxiliary_sysfs.c file (Greg)
v5-v6:
- removed concept of shared and exclusive and hence global xarray (Greg)
v4-v5:
- restore global mutex and replace refcount_t with simple integer (Greg)
v3->4:
- remove global mutex (Przemek)
v2->v3:
- fix function declaration in case SYSFS isn't defined
v1->v2:
- move #ifdefs from drivers/base/auxiliary.c to
include/linux/auxiliary_bus.h (Greg)
- use EXPORT_SYMBOL_GPL instead of EXPORT_SYMBOL (Greg)
- Fix kzalloc(ref) to kzalloc(*ref) (Simon)
- Add return description in auxiliary_device_sysfs_irq_add() kdoc (Simon)
- Fix auxiliary_irq_mode_show doc (kernel test boot)
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>
The code and documentation are more difficult to maintain when kept
separately. This is further compounded when the standard structure
documentation infrastructure is not used.
Move the documentation into the code, use the standard documentation
infrastructure, add current documented functions, and reference the text
in the rst file.
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20211202044305.4006853-8-ira.weiny@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The documentation for creating an auxiliary device is a 3 step not a 2
step process. Specifically the requirements of setting the name, id,
dev.release, and dev.parent fields was not clear as a precursor to the '2
step' process documented.
Clarify by declaring this a 3 step process starting with setting the
fields of struct auxiliary_device correctly.
Also add some sample code and tie the change into the rest of the
documentation.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20211202044305.4006853-2-ira.weiny@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
