drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT

The cacheinfo structures are alloced/freed by cpu online/offline
callbacks. Originally these were only used by sysfs to expose the
cache topology to user space. Without any in-kernel dependencies
CPUHP_AP_ONLINE_DYN was an appropriate choice.

resctrl has started using these structures to identify CPUs that
share a cache. It updates its 'domain' structures from cpu
online/offline callbacks. These depend on the cacheinfo structures
(resctrl_online_cpu()->domain_add_cpu()->get_cache_id()->
get_cpu_cacheinfo()).
These also run as CPUHP_AP_ONLINE_DYN.

Now that there is an in-kernel dependency, move the cacheinfo
work earlier so we know its done before resctrl's CPUHP_AP_ONLINE_DYN
work runs.

Fixes: 2264d9c74dda1 ("x86/intel_rdt: Build structures for each resource based on cache topology")
Cc: <[e-mail]>
Cc: Fenghua Yu <[e-mail]>
Cc: Reinette Chatre <[e-mail]>
Signed-off-by: James Morse <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/base/cacheinfo.c

···
 
 static int __init cacheinfo_sysfs_init(void)
 {
-	return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
+	return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
+				 "base/cacheinfo:online",
 				 cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
 }
 device_initcall(cacheinfo_sysfs_init);

include/linux/cpuhotplug.h

···
 	CPUHP_AP_WATCHDOG_ONLINE,
 	CPUHP_AP_WORKQUEUE_ONLINE,
 	CPUHP_AP_RCUTREE_ONLINE,
+	CPUHP_AP_BASE_CACHEINFO_ONLINE,
 	CPUHP_AP_ONLINE_DYN,
 	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,
 	CPUHP_AP_X86_HPET_ONLINE,