Revert "arm64/mpam: Fix mpam corrupt when cpu online"

hulk inclusion
category: bugfix
bugzilla: 189067, https://gitee.com/openeuler/kernel/issues/I7PN0A
CVE: NA

-------------------------------------------------

BUG 'sleeping function called from invalid context' reported when
setup MPAM driver, it was blamed to bc9e3f98 ("arm64/mpam:
Fix mpam corrupt when cpu online"), which reported a 'Bad PC' BUG,
but missing the right conclusion, finally disabling irqs before calling
cpuhp_setup_state() may only affect the probability of reproduction.

The reason why triggerring 'Bad PC' BUG report is because mpam_enable()
is __init type function, and may schedule out after calling
__cpuhp_setup_state()->__might_sleep(), so the space of mpam_enable()
might be freed after scheduling back.

As we have changed mpam_enable() to non-init type function, we can
revert commit bc9e3f98 directly, to solve these both two problems.

Fixes: bc9e3f98 ("arm64/mpam: Fix mpam corrupt when cpu online")
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>

arch/arm64/kernel/mpam/mpam_device.c

@@ -596,11 +596,9 @@ static void mpam_enable(struct work_struct *work)
 		pr_err("Failed to setup/init resctrl\n");
 	mutex_unlock(&mpam_devices_lock);
 
-	local_irq_disable();
 	mpam_cpuhp_state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
 						"mpam:online", mpam_cpu_online,
 						mpam_cpu_offline);
-	local_irq_enable();
 	if (mpam_cpuhp_state <= 0)
 		pr_err("Failed to re-register 'dyn' cpuhp callbacks");
 	mutex_unlock(&mpam_cpuhp_lock);