[patch 10/37] x86/cpu/cacheinfo: Remove cpu_callout_mask dependency

Thomas Gleixner
2023-04-14T23:45:06Z

cpu_callout_mask is used for the stop machine based MTRR/PAT init.

In preparation of moving the BP/AP synchronization to the core hotplug
code, use a private CPU mask for cacheinfo and manage it in the
starting/dying hotplug state.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/cpu/cacheinfo.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)

--- a/arch/x86/kernel/cpu/cacheinfo.c
+++ b/arch/x86/kernel/cpu/cacheinfo.c
@@ -39,6 +39,8 @@ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t
/* Shared L2 cache maps */
DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_l2c_shared_map);

+static cpumask_var_t cpu_cacheinfo_mask;
+
/* Kernel controls MTRR and/or PAT MSRs. */
unsigned int memory_caching_control __ro_after_init;

@@ -1172,8 +1174,10 @@ void cache_bp_restore(void)
cache_cpu_init();
}

-static int cache_ap_init(unsigned int cpu)
+static int cache_ap_online(unsigned int cpu)
{
+ cpumask_set_cpu(cpu, cpu_cacheinfo_mask);
+
if (!memory_caching_control || get_cache_aps_delayed_init())
return 0;

@@ -1191,11 +1195,17 @@ static int cache_ap_init(unsigned int cp
* lock to prevent MTRR entry changes
*/
stop_machine_from_inactive_cpu(cache_rendezvous_handler, NULL,
- cpu_callout_mask);
+ cpu_cacheinfo_mask);

return 0;
}

+static int cache_ap_offline(unsigned int cpu)
+{
+ cpumask_clear_cpu(cpu, cpu_cacheinfo_mask);
+ return 0;
+}
+
/*
* Delayed cache initialization for all AP's
*/
@@ -1210,9 +1220,12 @@ void cache_aps_init(void)

static int __init cache_ap_register(void)
{
+ zalloc_cpumask_var(&cpu_cacheinfo_mask, GFP_KERNEL);
+ cpumask_set_cpu(smp_processor_id(), cpu_cacheinfo_mask);
+
cpuhp_setup_state_nocalls(CPUHP_AP_CACHECTRL_STARTING,
"x86/cachectrl:starting",
- cache_ap_init, NULL);
+ cache_ap_online, cache_ap_offline);
return 0;
}
-core_initcall(cache_ap_register);
+early_initcall(cache_ap_register);