[PATCH v2 1/2] LoongArch: Remove clock setting during cpu hotplug stage

[Bibo Mao]

On physical machine we can save power by disabling clock of hot
removed cpu. However as different platforms require different
methods to configure clocks, the code is platform-specific, and
probably belongs to firmware/pmu or cpu regulator, rather than
generic arch/loongarch code.

Also there is no such register on QEMU virt machine since the
clock/frequency regulation is not emulated.

This patch removes the hard-coded clock register accessing in
generic loongarch cpu hotplug flow.

Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Reviewed-by:   WANG Xuerui <git@xxxxxxxxxx>
---
 arch/loongarch/kernel/smp.c | 29 -----------------------------
 include/linux/cpuhotplug.h  |  1 -
 2 files changed, 30 deletions(-)

diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
index 73cec62504fb..98b3e059d344 100644
--- a/arch/loongarch/kernel/smp.c
+++ b/arch/loongarch/kernel/smp.c
@@ -359,35 +359,6 @@ void play_dead(void)
 	play_dead_uncached(state_addr);
 }
 
-static int loongson3_enable_clock(unsigned int cpu)
-{
-	uint64_t core_id = cpu_data[cpu].core;
-	uint64_t package_id = cpu_data[cpu].package;
-
-	LOONGSON_FREQCTRL(package_id) |= 1 << (core_id * 4 + 3);
-
-	return 0;
-}
-
-static int loongson3_disable_clock(unsigned int cpu)
-{
-	uint64_t core_id = cpu_data[cpu].core;
-	uint64_t package_id = cpu_data[cpu].package;
-
-	LOONGSON_FREQCTRL(package_id) &= ~(1 << (core_id * 4 + 3));
-
-	return 0;
-}
-
-static int register_loongson3_notifier(void)
-{
-	return cpuhp_setup_state_nocalls(CPUHP_LOONGARCH_SOC_PREPARE,
-					 "loongarch/loongson:prepare",
-					 loongson3_enable_clock,
-					 loongson3_disable_clock);
-}
-early_initcall(register_loongson3_notifier);
-
 #endif
 
 /*
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 19f0dbfdd7fe..b66c5f389159 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -130,7 +130,6 @@ enum cpuhp_state {
 	CPUHP_ZCOMP_PREPARE,
 	CPUHP_TIMERS_PREPARE,
 	CPUHP_MIPS_SOC_PREPARE,
-	CPUHP_LOONGARCH_SOC_PREPARE,
 	CPUHP_BP_PREPARE_DYN,
 	CPUHP_BP_PREPARE_DYN_END		= CPUHP_BP_PREPARE_DYN + 20,
 	CPUHP_BRINGUP_CPU,
-- 
2.31.1