The following commit has been merged into the x86/cpu branch of tip: Commit-ID: 30f89e524becdbaa483b34902b079c9d4dfaa4a3 Gitweb: https://git.kernel.org/tip/30f89e524becdbaa483b34902b079c9d4dfaa4a3 Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Wed, 02 Nov 2022 08:47:11 +01:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Thu, 10 Nov 2022 13:12:45 +01:00 x86/cacheinfo: Switch cache_ap_init() to hotplug callback 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 <bp@xxxxxxxxx> Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lore.kernel.org/r/20221102074713.21493-15-jgross@xxxxxxxx Signed-off-by: Borislav Petkov <bp@xxxxxxx> --- 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 a0ef46e..ce9685f 100644 --- a/arch/x86/include/asm/cacheinfo.h +++ b/arch/x86/include/asm/cacheinfo.h @@ -16,7 +16,6 @@ void set_cache_aps_delayed_init(bool val); bool get_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 c830f85..f4e5aa2 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(bool val) { @@ -1174,10 +1175,10 @@ 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 || get_cache_aps_delayed_init()) - return; + return 0; /* * Ideally we should hold mtrr_mutex here to avoid MTRR entries @@ -1194,6 +1195,8 @@ void cache_ap_init(void) */ stop_machine_from_inactive_cpu(cache_rendezvous_handler, NULL, cpu_callout_mask); + + return 0; } /* @@ -1207,3 +1210,12 @@ void cache_aps_init(void) stop_machine(cache_rendezvous_handler, NULL, cpu_online_mask); set_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 fd058b5..bf4ac1c 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 1b61a48..82b311c 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(true); - smp_quirk_init_udelay(); speculative_store_bypass_ht_init(); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index f614479..0d277b4 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,
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