Instead of explicitly calling cache_ap_init() in
identify_secondary_cpu() use a cpu hotplug callback instead. By
registering the callback only after having started the non-boot CPUs
and initializing cache_aps_delayed_init with "true", calling
set_cache_aps_delayed_init() at boot time can be dropped.
It should be noted that this change results in cache_ap_init() being
called a little bit later when hotplugging CPUs. By using a new
hotplug slot right at the start of the low level bringup this is not
problematic, as no operations requiring a specific caching mode are
performed that early in CPU initialization.
Suggested-by: Borislav Petkov <[email protected]>
Signed-off-by: Juergen Gross <[email protected]>
---
V4:
- new patch
---
arch/x86/include/asm/cacheinfo.h | 1 -
arch/x86/kernel/cpu/cacheinfo.c | 18 +++++++++++++++---
arch/x86/kernel/cpu/common.c | 1 -
arch/x86/kernel/smpboot.c | 2 --
include/linux/cpuhotplug.h | 1 +
5 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/cacheinfo.h b/arch/x86/include/asm/cacheinfo.h
index 77fe39a11679..f6c521687535 100644
--- a/arch/x86/include/asm/cacheinfo.h
+++ b/arch/x86/include/asm/cacheinfo.h
@@ -15,7 +15,6 @@ void cache_enable(void);
void set_cache_aps_delayed_init(void);
void cache_bp_init(void);
void cache_bp_restore(void);
-void cache_ap_init(void);
void cache_aps_init(void);
#endif /* _ASM_X86_CACHEINFO_H */
diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c
index 40c304314513..48ce48827f87 100644
--- a/arch/x86/kernel/cpu/cacheinfo.c
+++ b/arch/x86/kernel/cpu/cacheinfo.c
@@ -11,6 +11,7 @@
#include <linux/slab.h>
#include <linux/cacheinfo.h>
#include <linux/cpu.h>
+#include <linux/cpuhotplug.h>
#include <linux/sched.h>
#include <linux/capability.h>
#include <linux/sysfs.h>
@@ -1139,7 +1140,7 @@ static void cache_cpu_init(void)
local_irq_restore(flags);
}
-static bool cache_aps_delayed_init;
+static bool cache_aps_delayed_init = true;
void set_cache_aps_delayed_init(void)
{
@@ -1169,10 +1170,10 @@ void cache_bp_restore(void)
cache_cpu_init();
}
-void cache_ap_init(void)
+static int cache_ap_init(unsigned int cpu)
{
if (!memory_caching_control || cache_aps_delayed_init)
- return;
+ return 0;
/*
* Ideally we should hold mtrr_mutex here to avoid mtrr entries
@@ -1189,6 +1190,8 @@ void cache_ap_init(void)
*/
stop_machine_from_inactive_cpu(cache_rendezvous_handler, NULL,
cpu_callout_mask);
+
+ return 0;
}
/*
@@ -1202,3 +1205,12 @@ void cache_aps_init(void)
stop_machine(cache_rendezvous_handler, NULL, cpu_online_mask);
cache_aps_delayed_init = false;
}
+
+static int __init cache_ap_register(void)
+{
+ cpuhp_setup_state_nocalls(CPUHP_AP_CACHECTRL_STARTING,
+ "x86/cachectrl:starting",
+ cache_ap_init, NULL);
+ return 0;
+}
+core_initcall(cache_ap_register);
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index fd058b547f8d..bf4ac1cb93d7 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1949,7 +1949,6 @@ void identify_secondary_cpu(struct cpuinfo_x86 *c)
#ifdef CONFIG_X86_32
enable_sep_cpu();
#endif
- cache_ap_init();
validate_apic_and_package_id(c);
x86_spec_ctrl_setup_ap();
update_srbds_msr();
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index fb225a02455f..d90be0a80560 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1429,8 +1429,6 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
uv_system_init();
- set_cache_aps_delayed_init();
-
smp_quirk_init_udelay();
speculative_store_bypass_ht_init();
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index f61447913db9..0d277b4b025a 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -140,6 +140,7 @@ enum cpuhp_state {
*/
CPUHP_AP_IDLE_DEAD,
CPUHP_AP_OFFLINE,
+ CPUHP_AP_CACHECTRL_STARTING,
CPUHP_AP_SCHED_STARTING,
CPUHP_AP_RCUTREE_DYING,
CPUHP_AP_CPU_PM_STARTING,
--
2.35.3