generic-ipi: Allow cpus not yet online to call smp_call_function with irqs disabled

Index: tip/kernel/smp.c
===================================================================
@@ -177,6 +177,11 @@ void generic_smp_call_function_interrupt
 	int cpu = get_cpu();
 
 	/*
+	 * Shouldn't receive this interrupt on a cpu that is not yet online.
+	 */
+	WARN_ON_ONCE(!cpu_online(cpu));
+
+	/*
 	 * Ensure entry is visible on call_function_queue after we have
 	 * entered the IPI. See comment in smp_call_function_many.
 	 * If we don't have this, then we may miss an entry on the list

@@ -230,6 +235,11 @@ void generic_smp_call_function_single_in
 	unsigned int data_flags;
 	LIST_HEAD(list);
 
+	/*
+	 * Shouldn't receive this interrupt on a cpu that is not yet online.
+	 */
+	WARN_ON_ONCE(!cpu_online(smp_processor_id()));
+
 	spin_lock(&q->lock);
 	list_replace_init(&q->list, &list);
 	spin_unlock(&q->lock);

@@ -285,8 +295,14 @@ int smp_call_function_single(int cpu, vo
 	 */
 	this_cpu = get_cpu();
 
-	/* Can deadlock when called with interrupts disabled */
-	WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
+	/*
+	 * Can deadlock when called with interrupts disabled.
+	 * We allow cpu's that are not yet online though, as no one else can
+	 * send smp call function interrupt to this cpu and as such deadlocks
+	 * can't happen.
+	 */
+	WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
+		     && !oops_in_progress);
 
 	if (cpu == this_cpu) {
 		local_irq_save(flags);

@@ -329,8 +345,14 @@ void __smp_call_function_single(int cpu,
 {
 	csd_lock(data);
 
-	/* Can deadlock when called with interrupts disabled */
-	WARN_ON_ONCE(wait && irqs_disabled() && !oops_in_progress);
+	/*
+	 * Can deadlock when called with interrupts disabled.
+	 * We allow cpu's that are not yet online though, as no one else can
+	 * send smp call function interrupt to this cpu and as such deadlocks
+	 * can't happen.
+	 */
+	WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled()
+		     && !oops_in_progress);
 
 	generic_exec_single(cpu, data, wait);
 }

@@ -365,8 +387,14 @@ void smp_call_function_many(const struct
 	unsigned long flags;
 	int cpu, next_cpu, this_cpu = smp_processor_id();
 
-	/* Can deadlock when called with interrupts disabled */
-	WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
+	/*
+	 * Can deadlock when called with interrupts disabled.
+	 * We allow cpu's that are not yet online though, as no one else can
+	 * send smp call function interrupt to this cpu and as such deadlocks
+	 * can't happen.
+	 */
+	WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
+		     && !oops_in_progress);
 
 	/* So, what's a CPU they want? Ignoring this one. */
 	cpu = cpumask_first_and(mask, cpu_online_mask);

Index: tip/arch/x86/include/asm/mtrr.h
===================================================================
@@ -121,8 +121,12 @@ extern int mtrr_del_page(int reg, unsign
 extern void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi);
 extern void mtrr_ap_init(void);
 extern void mtrr_bp_init(void);
+extern void set_mtrr_aps_delayed_init(void);
+extern void mtrr_aps_init(void);
+extern void mtrr_bp_restore(void);
 extern int mtrr_trim_uncached_memory(unsigned long end_pfn);
 extern int amd_special_default_mtrr(void);
+extern u32 mtrr_aps_delayed_init;
 #  else
 static inline u8 mtrr_type_lookup(u64 addr, u64 end)
 {

@@ -161,6 +165,9 @@ static inline void mtrr_centaur_report_m
 
 #define mtrr_ap_init() do {} while (0)
 #define mtrr_bp_init() do {} while (0)
+#define set_mtrr_aps_delayed_init() do {} while (0)
+#define mtrr_aps_init() do {} while (0)
+#define mtrr_bp_restore() do {} while (0)
 #  endif
 
 #ifdef CONFIG_COMPAT

82 lines not on this page · raw message

Index: tip/arch/x86/kernel/smpboot.c
===================================================================
@@ -1118,9 +1118,22 @@ void __init native_smp_prepare_cpus(unsi
 
 	if (is_uv_system())
 		uv_system_init();
+
+	set_mtrr_aps_delayed_init();
 out:
 	preempt_enable();
 }
+
+void arch_enable_nonboot_cpus_begin(void)
+{
+	set_mtrr_aps_delayed_init();
+}
+
+void arch_enable_nonboot_cpus_end(void)
+{
+	mtrr_aps_init();
+}
+
 /*
  * Early setup to make printk work.
  */

@@ -1142,6 +1155,7 @@ void __init native_smp_cpus_done(unsigne
 	setup_ioapic_dest();
 #endif
 	check_nmi_watchdog();
+	mtrr_aps_init();
 }
 
 static int __initdata setup_possible_cpus = -1;

Index: tip/arch/x86/power/cpu.c
===================================================================
@@ -224,7 +224,7 @@ static void __restore_processor_state(st
 	fix_processor_context();
 
 	do_fpu_end();
-	mtrr_ap_init();
+	mtrr_bp_restore();
 
 #ifdef CONFIG_X86_OLD_MCE
 	mcheck_init(&boot_cpu_data);

Index: tip/kernel/cpu.c
===================================================================
@@ -413,6 +413,14 @@ int disable_nonboot_cpus(void)
 	return error;
 }
 
+void __weak arch_enable_nonboot_cpus_begin(void)
+{
+}
+
+void __weak arch_enable_nonboot_cpus_end(void)
+{
+}
+
 void __ref enable_nonboot_cpus(void)
 {
 	int cpu, error;

@@ -424,6 +432,9 @@ void __ref enable_nonboot_cpus(void)
 		goto out;
 
 	printk("Enabling non-boot CPUs ...\n");
+
+	arch_enable_nonboot_cpus_begin();
+
 	for_each_cpu(cpu, frozen_cpus) {
 		error = _cpu_up(cpu, 1);
 		if (!error) {

@@ -432,6 +443,9 @@ void __ref enable_nonboot_cpus(void)
 		}
 		printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
 	}
+
+	arch_enable_nonboot_cpus_end();
+
 	cpumask_clear(frozen_cpus);
 out:
 	cpu_maps_update_done();