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 4 depends on patches 1, 2, and 3.
Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
---
Changes in v5:
- Move tegra cbb driver init to core_initcall and module_kset init to pure_initcall (Gary)
- Rename coresight_init_driver() to coresight_init_driver_with_owner(), and
declare function prototype before use (Leo)
- Merge doc change patch with code change patch, so that __platform_register_drivers()
prototype is changed everywhere in the same patch
- Link to v4: https://patch.msgid.link/20260427-acpi_mod_name-v4-0-22b42240c9bf@sony.com
Changes in v4:
- Initialize module_kset in do_basic_setup() before do_initcalls() (Gary)
- Add commit body to the documentation patch (Greg)
- Link to v3: https://patch.msgid.link/20260422-acpi_mod_name-v3-0-a184eff9ff6f@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@arm.com>
To: Mike Leach <mike.leach@linaro.org>
To: James Clark <james.clark@linaro.org>
To: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
To: Danilo Krummrich <dakr@kernel.org>
To: Miguel Ojeda <ojeda@kernel.org>
To: Boqun Feng <boqun@kernel.org>
To: Gary Guo <gary@garyguo.net>
To: Björn Roy Baron <bjorn3_gh@protonmail.com>
To: Benno Lossin <lossin@kernel.org>
To: Andreas Hindborg <a.hindborg@kernel.org>
To: Alice Ryhl <aliceryhl@google.com>
To: Trevor Gross <tmgross@umich.edu>
To: Jonathan Corbet <corbet@lwn.net>
To: Shuah Khan <skhan@linuxfoundation.org>
To: Luis Chamberlain <mcgrof@kernel.org>
To: Petr Pavlu <petr.pavlu@suse.com>
To: Daniel Gomez <da.gomez@kernel.org>
To: Sami Tolvanen <samitolvanen@google.com>
To: Aaron Tomlin <atomlin@atomlin.com>
To: Mike Leach <mike.leach@arm.com>
To: Leo Yan <leo.yan@arm.com>
To: Thierry Reding <thierry.reding@kernel.org>
To: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-kernel@vger.kernel.org
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: driver-core@lists.linux.dev
Cc: rust-for-linux@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: Shashank Balaji <shashank.mahadasyam@sony.com>
Cc: Rahul Bukte <rahul.bukte@sony.com>
Cc: Daniel Palmer <daniel.palmer@sony.com>
Cc: Tim Bird <tim.bird@sony.com>
Cc: linux-modules@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: Sumit Gupta <sumitg@nvidia.com>
---
Shashank Balaji (4):
soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall
kernel: param: initialize module_kset in a pure_initcall
coresight: pass THIS_MODULE implicitly through a macro
driver core: platform: set mod_name in driver registration
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 +-
drivers/soc/tegra/cbb/tegra194-cbb.c | 2 +-
drivers/soc/tegra/cbb/tegra234-cbb.c | 2 +-
include/linux/coresight.h | 7 +++++--
include/linux/platform_device.h | 17 +++++++++--------
kernel/params.c | 2 +-
rust/kernel/platform.rs | 4 +++-
18 files changed, 50 insertions(+), 39 deletions(-)
---
base-commit: 5200f5f493f79f14bbdc349e402a40dfb32f23c8
change-id: 20260416-acpi_mod_name-f645a76e337b
Best regards,
--
Shashank Balaji <shashank.mahadasyam@sony.com>