[PATCH v3 0/4] Enable sysfs module symlink for more built-in drivers
Shashank Balaji
shashank.mahadasyam at sony.com
Wed Apr 22 02:49:02 PDT 2026
struct device_driver's mod_name is not set by a number of bus' driver registration
functions. Without that, built-in drivers don't have the module symlink in sysfs.
We want this to go from unbound driver name -> module name -> kernel config name.
This is useful on embedded platforms to minimize kernel config, reduce kernel size,
and reduce boot time.
In order to achieve this, mod_name has to be set to KBUILD_MODNAME, and this has
to be done for all buses which don't yet do this.
Here are some treewide stats:
- 110 registration functions across all bus types
- 20 of them set mod_name
- Remaining 90 do not set mod_name:
1. 36 functions under pattern 1:
They have a __register function + register macro. KBUILD_MODNAME needs to
be passed and the function needs to take mod_name as input.
2. 42 functions under pattern 2:
These have no macro wrapper. They need a double-underscore rename + macro
wrapper to make them similar to pattern 1.
3. Remaining 12 do not have such a clean registration interface. More analysis
is required.
We plan to start with pattern 1, since it's the easiest category of changes.
Within that, for now we're only sending the platform patch. If we get the go-ahead
on that, we'll send the remaining ones.
Patch 3 depends on patches 1 and 2.
Co-developed-by: Rahul Bukte <rahul.bukte at sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte at sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam at sony.com>
---
Changes in v3:
- Initialize module_kset on-demand (Greg)
- Make coresight driver registration happen through a macro (Greg)
- Split up the patch adding mod_name to platform driver registrations (Greg)
- Link to v2: https://patch.msgid.link/20260421-acpi_mod_name-v2-0-e73f9310dad3@sony.com
Changes in v2:
- Drop acpi patch, send platform instead (Rafael)
- Link to v1: https://patch.msgid.link/20260416-acpi_mod_name-v1-0-1a4d96fd86c9@sony.com
To: Suzuki K Poulose <suzuki.poulose at arm.com>
To: Mike Leach <mike.leach at linaro.org>
To: James Clark <james.clark at linaro.org>
To: Alexander Shishkin <alexander.shishkin at linux.intel.com>
To: Maxime Coquelin <mcoquelin.stm32 at gmail.com>
To: Alexandre Torgue <alexandre.torgue at foss.st.com>
To: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
To: "Rafael J. Wysocki" <rafael at kernel.org>
To: Danilo Krummrich <dakr at kernel.org>
To: Miguel Ojeda <ojeda at kernel.org>
To: Boqun Feng <boqun at kernel.org>
To: Gary Guo <gary at garyguo.net>
To: Björn Roy Baron <bjorn3_gh at protonmail.com>
To: Benno Lossin <lossin at kernel.org>
To: Andreas Hindborg <a.hindborg at kernel.org>
To: Alice Ryhl <aliceryhl at google.com>
To: Trevor Gross <tmgross at umich.edu>
To: Richard Cochran <richardcochran at gmail.com>
To: Jonathan Corbet <corbet at lwn.net>
To: Shuah Khan <skhan at linuxfoundation.org>
Cc: linux-kernel at vger.kernel.org
Cc: coresight at lists.linaro.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: driver-core at lists.linux.dev
Cc: rust-for-linux at vger.kernel.org
Cc: linux-doc at vger.kernel.org
Cc: Shashank Balaji <shashank.mahadasyam at sony.com>
Cc: Rahul Bukte <rahul.bukte at sony.com>
Cc: Daniel Palmer <daniel.palmer at sony.com>
Cc: Tim Bird <tim.bird at sony.com>
---
Shashank Balaji (4):
kernel: param: initialize module_kset on-demand
coresight: pass THIS_MODULE implicitly through a macro
driver core: platform: set mod_name in driver registration
docs: driver-api: add mod_name argument to __platform_register_drivers()
Documentation/driver-api/driver-model/platform.rst | 3 +-
drivers/base/platform.c | 21 +++++++----
drivers/hwtracing/coresight/coresight-catu.c | 2 +-
drivers/hwtracing/coresight/coresight-core.c | 9 ++---
drivers/hwtracing/coresight/coresight-cpu-debug.c | 3 +-
drivers/hwtracing/coresight/coresight-funnel.c | 3 +-
drivers/hwtracing/coresight/coresight-replicator.c | 3 +-
drivers/hwtracing/coresight/coresight-stm.c | 2 +-
drivers/hwtracing/coresight/coresight-tmc-core.c | 2 +-
drivers/hwtracing/coresight/coresight-tnoc.c | 2 +-
drivers/hwtracing/coresight/coresight-tpdm.c | 3 +-
drivers/hwtracing/coresight/coresight-tpiu.c | 2 +-
include/linux/coresight.h | 7 ++--
include/linux/platform_device.h | 17 ++++-----
kernel/params.c | 41 +++++++++++++---------
rust/kernel/platform.rs | 4 ++-
16 files changed, 72 insertions(+), 52 deletions(-)
---
base-commit: 6596a02b207886e9e00bb0161c7fd59fea53c081
change-id: 20260416-acpi_mod_name-f645a76e337b
Best regards,
--
Shashank Balaji <shashank.mahadasyam at sony.com>
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