Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c lockdep: Move early boot local IRQ enable/disable status to init/main.c

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel…
…/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c lockdep: Move early boot local IRQ enable/disable status to init/main.c
Linus Torvalds
2 parents d551d81d6a bd924e8cbd
Showing 7 changed files Side-by-side Diff
arch/x86/xen/enlighten.c
include/linux/kernel.h
include/linux/lockdep.h
init/main.c
kernel/lockdep.c
kernel/smp.c
kernel/trace/trace_irqsoff.c
@@ -1194,7 +1194,7 @@
 	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
  
 	local_irq_disable();
-	early_boot_irqs_off();
+	early_boot_irqs_disabled = true;
  
 	memblock_init();
  
@@ -243,6 +243,8 @@
 extern unsigned long get_taint(void);
 extern int root_mountflags;
  
+extern bool early_boot_irqs_disabled;
+
 /* Values used for system_state */
 extern enum system_states {
 	SYSTEM_BOOTING,
@@ -436,16 +436,8 @@
 #endif /* CONFIG_LOCKDEP */
  
 #ifdef CONFIG_TRACE_IRQFLAGS
-extern void early_boot_irqs_off(void);
-extern void early_boot_irqs_on(void);
 extern void print_irqtrace_events(struct task_struct *curr);
 #else
-static inline void early_boot_irqs_off(void)
-{
-}
-static inline void early_boot_irqs_on(void)
-{
-}
 static inline void print_irqtrace_events(struct task_struct *curr)
 {
 }
@@ -96,6 +96,15 @@
 extern void tc_init(void);
 #endif
  
+/*
+ * Debug helper: via this flag we know that we are in 'early bootup code'
+ * where only the boot processor is running with IRQ disabled.  This means
+ * two things - IRQ must not be enabled before the flag is cleared and some
+ * operations which are not allowed with IRQ disabled are allowed while the
+ * flag is set.
+ */
+bool early_boot_irqs_disabled __read_mostly;
+
 enum system_states system_state __read_mostly;
 EXPORT_SYMBOL(system_state);
  
@@ -554,7 +563,7 @@
 	cgroup_init_early();
  
 	local_irq_disable();
-	early_boot_irqs_off();
+	early_boot_irqs_disabled = true;
  
 /*
  * Interrupts are still disabled. Do necessary setups, then
@@ -621,7 +630,7 @@
 	if (!irqs_disabled())
 		printk(KERN_CRIT "start_kernel(): bug: interrupts were "
 				 "enabled early\n");
-	early_boot_irqs_on();
+	early_boot_irqs_disabled = false;
 	local_irq_enable();
  
 	/* Interrupts are enabled now so all GFP allocations are safe. */
@@ -2292,22 +2292,6 @@
 }
  
 /*
- * Debugging helper: via this flag we know that we are in
- * 'early bootup code', and will warn about any invalid irqs-on event:
- */
-static int early_boot_irqs_enabled;
-
-void early_boot_irqs_off(void)
-{
-	early_boot_irqs_enabled = 0;
-}
-
-void early_boot_irqs_on(void)
-{
-	early_boot_irqs_enabled = 1;
-}
-
-/*
  * Hardirqs will be enabled:
  */
 void trace_hardirqs_on_caller(unsigned long ip)
@@ -2319,7 +2303,7 @@
 	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
  
-	if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled)))
+	if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled)))
 		return;
  
 	if (unlikely(curr->hardirqs_enabled)) {
@@ -459,7 +459,7 @@
 	 * can't happen.
 	 */
 	WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
-		     && !oops_in_progress);
+		     && !oops_in_progress && !early_boot_irqs_disabled);
  
 	/* So, what's a CPU they want? Ignoring this one. */
 	cpu = cpumask_first_and(mask, cpu_online_mask);
  
  
  
@@ -572,17 +572,20 @@
 #endif /* USE_GENERIC_SMP_HELPERS */
  
 /*
- * Call a function on all processors
+ * Call a function on all processors.  May be used during early boot while
+ * early_boot_irqs_disabled is set.  Use local_irq_save/restore() instead
+ * of local_irq_disable/enable().
  */
 int on_each_cpu(void (*func) (void *info), void *info, int wait)
 {
+	unsigned long flags;
 	int ret = 0;
  
 	preempt_disable();
 	ret = smp_call_function(func, info, wait);
-	local_irq_disable();
+	local_irq_save(flags);
 	func(info);
-	local_irq_enable();
+	local_irq_restore(flags);
 	preempt_enable();
 	return ret;
 }
@@ -453,14 +453,6 @@
  * Stubs:
  */
  
-void early_boot_irqs_off(void)
-{
-}
-
-void early_boot_irqs_on(void)
-{
-}
-
 void trace_softirqs_on(unsigned long ip)
 {
 }
...	...	@@ -1194,7 +1194,7 @@
1194	1194	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1195	1195
1196	1196	local_irq_disable();
1197		- early_boot_irqs_off();
	1197	+ early_boot_irqs_disabled = true;
1198	1198
1199	1199	memblock_init();
1200	1200
...	...	@@ -243,6 +243,8 @@
243	243	extern unsigned long get_taint(void);
244	244	extern int root_mountflags;
245	245
	246	+extern bool early_boot_irqs_disabled;
	247	+
246	248	/* Values used for system_state */
247	249	extern enum system_states {
248	250	SYSTEM_BOOTING,
...	...	@@ -436,16 +436,8 @@
436	436	#endif /* CONFIG_LOCKDEP */
437	437
438	438	#ifdef CONFIG_TRACE_IRQFLAGS
439		-extern void early_boot_irqs_off(void);
440		-extern void early_boot_irqs_on(void);
441	439	extern void print_irqtrace_events(struct task_struct *curr);
442	440	#else
443		-static inline void early_boot_irqs_off(void)
444		-{
445		-}
446		-static inline void early_boot_irqs_on(void)
447		-{
448		-}
449	441	static inline void print_irqtrace_events(struct task_struct *curr)
450	442	{
451	443	}
...	...	@@ -96,6 +96,15 @@
96	96	extern void tc_init(void);
97	97	#endif
98	98
	99	+/*
	100	+ * Debug helper: via this flag we know that we are in 'early bootup code'
	101	+ * where only the boot processor is running with IRQ disabled. This means
	102	+ * two things - IRQ must not be enabled before the flag is cleared and some
	103	+ * operations which are not allowed with IRQ disabled are allowed while the
	104	+ * flag is set.
	105	+ */
	106	+bool early_boot_irqs_disabled __read_mostly;
	107	+
99	108	enum system_states system_state __read_mostly;
100	109	EXPORT_SYMBOL(system_state);
101	110
...	...	@@ -554,7 +563,7 @@
554	563	cgroup_init_early();
555	564
556	565	local_irq_disable();
557		- early_boot_irqs_off();
	566	+ early_boot_irqs_disabled = true;
558	567
559	568	/*
560	569	* Interrupts are still disabled. Do necessary setups, then
...	...	@@ -621,7 +630,7 @@
621	630	if (!irqs_disabled())
622	631	printk(KERN_CRIT "start_kernel(): bug: interrupts were "
623	632	"enabled early\n");
624		- early_boot_irqs_on();
	633	+ early_boot_irqs_disabled = false;
625	634	local_irq_enable();
626	635
627	636	/* Interrupts are enabled now so all GFP allocations are safe. */
...	...	@@ -2292,22 +2292,6 @@
2292	2292	}
2293	2293
2294	2294	/*
2295		- * Debugging helper: via this flag we know that we are in
2296		- * 'early bootup code', and will warn about any invalid irqs-on event:
2297		- */
2298		-static int early_boot_irqs_enabled;
2299		-
2300		-void early_boot_irqs_off(void)
2301		-{
2302		- early_boot_irqs_enabled = 0;
2303		-}
2304		-
2305		-void early_boot_irqs_on(void)
2306		-{
2307		- early_boot_irqs_enabled = 1;
2308		-}
2309		-
2310		-/*
2311	2295	* Hardirqs will be enabled:
2312	2296	*/
2313	2297	void trace_hardirqs_on_caller(unsigned long ip)
...	...	@@ -2319,7 +2303,7 @@
2319	2303	if (unlikely(!debug_locks \|\| current->lockdep_recursion))
2320	2304	return;
2321	2305
2322		- if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled)))
	2306	+ if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled)))
2323	2307	return;
2324	2308
2325	2309	if (unlikely(curr->hardirqs_enabled)) {
...	...	@@ -459,7 +459,7 @@
459	459	* can't happen.
460	460	*/
461	461	WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
462		- && !oops_in_progress);
	462	+ && !oops_in_progress && !early_boot_irqs_disabled);
463	463
464	464	/* So, what's a CPU they want? Ignoring this one. */
465	465	cpu = cpumask_first_and(mask, cpu_online_mask);
466	466
467	467
468	468
...	...	@@ -572,17 +572,20 @@
572	572	#endif /* USE_GENERIC_SMP_HELPERS */
573	573
574	574	/*
575		- * Call a function on all processors
	575	+ * Call a function on all processors. May be used during early boot while
	576	+ * early_boot_irqs_disabled is set. Use local_irq_save/restore() instead
	577	+ * of local_irq_disable/enable().
576	578	*/
577	579	int on_each_cpu(void (func) (void info), void *info, int wait)
578	580	{
	581	+ unsigned long flags;
579	582	int ret = 0;
580	583
581	584	preempt_disable();
582	585	ret = smp_call_function(func, info, wait);
583		- local_irq_disable();
	586	+ local_irq_save(flags);
584	587	func(info);
585		- local_irq_enable();
	588	+ local_irq_restore(flags);
586	589	preempt_enable();
587	590	return ret;
588	591	}
...	...	@@ -453,14 +453,6 @@
453	453	* Stubs:
454	454	*/
455	455
456		-void early_boot_irqs_off(void)
457		-{
458		-}
459		-
460		-void early_boot_irqs_on(void)
461		-{
462		-}
463		-
464	456	void trace_softirqs_on(unsigned long ip)
465	457	{
466	458	}