drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()
authorThomas Gleixner <tglx@linutronix.de>
Tue, 31 Aug 2021 11:48:34 +0000 (13:48 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 1 Sep 2021 08:29:10 +0000 (10:29 +0200)
commit4b92d4add5f6dcf21275185c997d6ecb800054cd
tree78f40ccaf493bb6cce3c76e99adac5077972b5e0
parent8596e589b787732c8346f0482919e83cc9362db1
drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()

DEFINE_SMP_CALL_CACHE_FUNCTION() was usefel before the CPU hotplug rework
to ensure that the cache related functions are called on the upcoming CPU
because the notifier itself could run on any online CPU.

The hotplug state machine guarantees that the callbacks are invoked on the
upcoming CPU. So there is no need to have this SMP function call
obfuscation. That indirection was missed when the hotplug notifiers were
converted.

This also solves the problem of ARM64 init_cache_level() invoking ACPI
functions which take a semaphore in that context. That's invalid as SMP
function calls run with interrupts disabled. Running it just from the
callback in context of the CPU hotplug thread solves this.

Fixes: 8571890e1513 ("arm64: Add support for ACPI based firmware tables")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/871r69ersb.ffs@tglx
arch/arm64/kernel/cacheinfo.c
arch/mips/kernel/cacheinfo.c
arch/riscv/kernel/cacheinfo.c
arch/x86/kernel/cpu/cacheinfo.c
include/linux/cacheinfo.h