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)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 26 Sep 2021 12:08:59 +0000 (14:08 +0200)
commitb9a1526d51744075a6245d3f3a5544b10a5405c9
treec5a425be76f14886756b21594e14836920fa1c45
parent45bd9dd1bee8aedc4cbd409b1ba7f9b4f941eea6
drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()

[ Upstream commit 4b92d4add5f6dcf21275185c997d6ecb800054cd ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
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