[PATCH v1 0/4] Make platform profiles firmware independent

[Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>]

Make platform profile selection independent of ACPI firmware.

The provider API already uses struct device, profile enums and callbacks;
it does not require an ACPI handle or firmware node. However, the core is
built under drivers/acpi/, its Kconfig symbol depends implicitly on ACPI,
initialization fails when ACPI is disabled, and the system-wide profile
interface is only exposed under /sys/firmware/acpi/.

This series moves the core to drivers/platform/profile/ and introduces
CONFIG_PLATFORM_PROFILE, updating all existing provider selectors. It
retains the tristate configuration and platform_profile module name.
Firmware-specific discovery and profile operations remain with providers.
The core can also be selected directly through its Kconfig prompt.

An optional ACPI adapter obtains the legacy sysfs kobject and is linked
into the same module. The generic core contains no ACPI types or symbols
and initializes without ACPI support or with ACPI disabled at boot.
The existing /sys/firmware/acpi/platform_profile and
/sys/firmware/acpi/platform_profile_choices attributes remain available
on active ACPI systems.

The new system-wide interface is:

  /sys/kernel/platform_profile/choices
  /sys/kernel/platform_profile/profile

Both aggregate frontends use the same callbacks, handler set and profile
semantics. The per-provider /sys/class/platform-profile/ interface is
preserved. Notifications cover both aggregate frontends and direct
per-provider writes. The new sysfs location is proposed ABI.

The first patch fixes the lock/lifetime boundary before adding another
frontend: sysfs teardown must not drain callbacks while holding the mutex
those callbacks need. A separate registration mutex serializes lifecycle
changes, while a profile-lock-protected handler list determines aggregate
membership independently of the class device's teardown state.

The second patch extracts the core and uses subsys_initcall_sync() so it
initializes after ACPI and before built-in thermal and CPUFreq consumers.
The third adds the generic aggregate interface, and the fourth documents
the interfaces and extends maintainer coverage.

Validation:

  - ARM64 built-in core with CONFIG_ACPI=n: W=1 build and sparse.
  - x86 modular core with CONFIG_ACPI=y: W=1 object build and sparse.
  - Full x86 kernel link and QEMU boot with lockdep and list debugging,
    with active ACPI and with acpi=off.
  - Firmware-less providers exercising common and hidden choices,
    profile reads/writes, invalid input, mixed profiles, cycling,
    partial callback failures, POLLPRI and legacy/generic shared state.
  - Concurrent sysfs I/O with two persistent providers while a third
    provider is registered and removed 200 times, last-provider attribute
    removal and repeated provider module reloads.

The provider API and profile names are unchanged. Aggregate writes retain
their sequential, non-transactional behavior: a failing callback does not
roll back providers already updated.

Daniel Lezcano (4):
  platform profile: Separate handler locking from sysfs lifetime
  platform profile: Extract the core from ACPI
  platform profile: Add firmware-neutral aggregate sysfs interface
  platform profile: Document firmware-independent profile selection

 .../ABI/testing/sysfs-class-platform-profile  |   2 +-
 .../ABI/testing/sysfs-kernel-platform_profile |  30 +++
 .../ABI/testing/sysfs-platform_profile        |   7 +-
 .../userspace-api/sysfs-platform_profile.rst  |  41 +++-
 MAINTAINERS                                   |   6 +
 drivers/acpi/Kconfig                          |   3 -
 drivers/acpi/Makefile                         |   1 -
 drivers/cpufreq/Kconfig.x86                   |   2 +-
 drivers/platform/Kconfig                      |  16 ++
 drivers/platform/Makefile                     |   2 +
 drivers/platform/profile/Makefile             |   5 +
 drivers/platform/profile/acpi.c               |  15 ++
 .../profile/core.c}                           | 195 +++++++++++++-----
 drivers/platform/profile/profile.h            |  17 ++
 drivers/platform/surface/Kconfig              |   6 +-
 drivers/platform/x86/Kconfig                  |  10 +-
 drivers/platform/x86/amd/pmf/Kconfig          |   2 +-
 drivers/platform/x86/dell/Kconfig             |   4 +-
 drivers/platform/x86/hp/Kconfig               |   2 +-
 drivers/platform/x86/lenovo/Kconfig           |   6 +-
 drivers/thermal/intel/int340x_thermal/Kconfig |   2 +-
 include/linux/platform_profile.h              |   3 +
 22 files changed, 288 insertions(+), 89 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-kernel-platform_profile
 create mode 100644 drivers/platform/profile/Makefile
 create mode 100644 drivers/platform/profile/acpi.c
 rename drivers/{acpi/platform_profile.c => platform/profile/core.c} (79%)
 create mode 100644 drivers/platform/profile/profile.h


base-commit: d0cd1e850e1602729dd60dc3c5fd96f80e0cdc5d
-- 
2.43.0