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										 |  |  | #include <linux/cpumask.h>
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							|  |  |  | #include <linux/interrupt.h>
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							|  |  |  | #include <linux/init.h>
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							|  |  |  | #include <linux/mm.h>
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							|  |  |  | #include <linux/delay.h>
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							|  |  |  | #include <linux/spinlock.h>
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							|  |  |  | #include <linux/kernel_stat.h>
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							|  |  |  | #include <linux/mc146818rtc.h>
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							|  |  |  | #include <linux/cache.h>
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							|  |  |  | #include <linux/cpu.h>
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							|  |  |  | #include <linux/module.h>
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							|  |  |  | #include <asm/smp.h>
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							|  |  |  | #include <asm/mtrr.h>
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							|  |  |  | #include <asm/tlbflush.h>
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							|  |  |  | #include <asm/mmu_context.h>
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										 |  |  | #include <asm/apic.h>
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										 |  |  | #include <asm/proto.h>
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										 |  |  | #include <asm/ipi.h>
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										 |  |  | void default_send_IPI_mask_sequence_phys(const struct cpumask *mask, int vector) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	unsigned long query_cpu; | 
					
						
							|  |  |  | 	unsigned long flags; | 
					
						
							|  |  |  | 
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							|  |  |  | 	/*
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							|  |  |  | 	 * Hack. The clustered APIC addressing mode doesn't allow us to send | 
					
						
							|  |  |  | 	 * to an arbitrary mask, so I do a unicast to each CPU instead. | 
					
						
							|  |  |  | 	 * - mbligh | 
					
						
							|  |  |  | 	 */ | 
					
						
							|  |  |  | 	local_irq_save(flags); | 
					
						
							|  |  |  | 	for_each_cpu(query_cpu, mask) { | 
					
						
							|  |  |  | 		__default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, | 
					
						
							|  |  |  | 				query_cpu), vector, APIC_DEST_PHYSICAL); | 
					
						
							|  |  |  | 	} | 
					
						
							|  |  |  | 	local_irq_restore(flags); | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | void default_send_IPI_mask_allbutself_phys(const struct cpumask *mask, | 
					
						
							|  |  |  | 						 int vector) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	unsigned int this_cpu = smp_processor_id(); | 
					
						
							|  |  |  | 	unsigned int query_cpu; | 
					
						
							|  |  |  | 	unsigned long flags; | 
					
						
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							|  |  |  | 	/* See Hack comment above */ | 
					
						
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							|  |  |  | 	local_irq_save(flags); | 
					
						
							|  |  |  | 	for_each_cpu(query_cpu, mask) { | 
					
						
							|  |  |  | 		if (query_cpu == this_cpu) | 
					
						
							|  |  |  | 			continue; | 
					
						
							|  |  |  | 		__default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, | 
					
						
							|  |  |  | 				 query_cpu), vector, APIC_DEST_PHYSICAL); | 
					
						
							|  |  |  | 	} | 
					
						
							|  |  |  | 	local_irq_restore(flags); | 
					
						
							|  |  |  | } | 
					
						
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										 |  |  | #ifdef CONFIG_X86_32
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										 |  |  | void default_send_IPI_mask_sequence_logical(const struct cpumask *mask, | 
					
						
							|  |  |  | 						 int vector) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	unsigned long flags; | 
					
						
							|  |  |  | 	unsigned int query_cpu; | 
					
						
							|  |  |  | 
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							|  |  |  | 	/*
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							|  |  |  | 	 * Hack. The clustered APIC addressing mode doesn't allow us to send | 
					
						
							|  |  |  | 	 * to an arbitrary mask, so I do a unicasts to each CPU instead. This | 
					
						
							|  |  |  | 	 * should be modified to do 1 message per cluster ID - mbligh | 
					
						
							|  |  |  | 	 */ | 
					
						
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							|  |  |  | 	local_irq_save(flags); | 
					
						
							|  |  |  | 	for_each_cpu(query_cpu, mask) | 
					
						
							|  |  |  | 		__default_send_IPI_dest_field( | 
					
						
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										 |  |  | 			early_per_cpu(x86_cpu_to_logical_apicid, query_cpu), | 
					
						
							|  |  |  | 			vector, apic->dest_logical); | 
					
						
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										 |  |  | 	local_irq_restore(flags); | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask, | 
					
						
							|  |  |  | 						 int vector) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	unsigned long flags; | 
					
						
							|  |  |  | 	unsigned int query_cpu; | 
					
						
							|  |  |  | 	unsigned int this_cpu = smp_processor_id(); | 
					
						
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							|  |  |  | 	/* See Hack comment above */ | 
					
						
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							|  |  |  | 	local_irq_save(flags); | 
					
						
							|  |  |  | 	for_each_cpu(query_cpu, mask) { | 
					
						
							|  |  |  | 		if (query_cpu == this_cpu) | 
					
						
							|  |  |  | 			continue; | 
					
						
							|  |  |  | 		__default_send_IPI_dest_field( | 
					
						
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										 |  |  | 			early_per_cpu(x86_cpu_to_logical_apicid, query_cpu), | 
					
						
							|  |  |  | 			vector, apic->dest_logical); | 
					
						
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										 |  |  | 		} | 
					
						
							|  |  |  | 	local_irq_restore(flags); | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | /*
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							|  |  |  |  * This is only used on smaller machines. | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | void default_send_IPI_mask_logical(const struct cpumask *cpumask, int vector) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	unsigned long mask = cpumask_bits(cpumask)[0]; | 
					
						
							|  |  |  | 	unsigned long flags; | 
					
						
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										 |  |  | 	if (!mask) | 
					
						
							| 
									
										
											  
											
												x86: don't send an IPI to the empty set of CPU's
The default_send_IPI_mask_logical() function uses the "flat" APIC mode
to send an IPI to a set of CPU's at once, but if that set happens to be
empty, some older local APIC's will apparently be rather unhappy.  So
just warn if a caller gives us an empty mask, and ignore it.
This fixes a regression in 2.6.30.x, due to commit 4595f9620 ("x86:
change flush_tlb_others to take a const struct cpumask"), documented
here:
	http://bugzilla.kernel.org/show_bug.cgi?id=13933
which causes a silent lock-up.  It only seems to happen on PPro, P2, P3
and Athlon XP cores.  Most developers sadly (or not so sadly, if you're
a developer..) have more modern CPU's.  Also, on x86-64 we don't use the
flat APIC mode, so it would never trigger there even if the APIC didn't
like sending an empty IPI mask.
Reported-by: Pavel Vilim <wylda@volny.cz>
Reported-and-tested-by: Thomas Björnell <thomas.bjornell@gmail.com>
Reported-and-tested-by: Martin Rogge <marogge@onlinehome.de>
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
											
										 
											2009-08-21 09:23:57 -07:00
										 |  |  | 		return; | 
					
						
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										 |  |  | 	local_irq_save(flags); | 
					
						
							|  |  |  | 	WARN_ON(mask & ~cpumask_bits(cpu_online_mask)[0]); | 
					
						
							|  |  |  | 	__default_send_IPI_dest_field(mask, vector, apic->dest_logical); | 
					
						
							|  |  |  | 	local_irq_restore(flags); | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | void default_send_IPI_allbutself(int vector) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	/*
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							|  |  |  | 	 * if there are no other CPUs in the system then we get an APIC send | 
					
						
							|  |  |  | 	 * error if we try to broadcast, thus avoid sending IPIs in this case. | 
					
						
							|  |  |  | 	 */ | 
					
						
							|  |  |  | 	if (!(num_online_cpus() > 1)) | 
					
						
							|  |  |  | 		return; | 
					
						
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							|  |  |  | 	__default_local_send_IPI_allbutself(vector); | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | void default_send_IPI_all(int vector) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	__default_local_send_IPI_all(vector); | 
					
						
							|  |  |  | } | 
					
						
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										 |  |  | void default_send_IPI_self(int vector) | 
					
						
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										 |  |  | { | 
					
						
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										 |  |  | 	__default_send_IPI_shortcut(APIC_DEST_SELF, vector, apic->dest_logical); | 
					
						
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										 |  |  | } | 
					
						
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							|  |  |  | /* must come after the send_IPI functions above for inlining */ | 
					
						
							|  |  |  | static int convert_apicid_to_cpu(int apic_id) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	int i; | 
					
						
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							|  |  |  | 	for_each_possible_cpu(i) { | 
					
						
							|  |  |  | 		if (per_cpu(x86_cpu_to_apicid, i) == apic_id) | 
					
						
							|  |  |  | 			return i; | 
					
						
							|  |  |  | 	} | 
					
						
							|  |  |  | 	return -1; | 
					
						
							|  |  |  | } | 
					
						
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							|  |  |  | int safe_smp_processor_id(void) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	int apicid, cpuid; | 
					
						
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										 |  |  | 	if (!cpu_has_apic) | 
					
						
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										 |  |  | 		return 0; | 
					
						
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							|  |  |  | 	apicid = hard_smp_processor_id(); | 
					
						
							|  |  |  | 	if (apicid == BAD_APICID) | 
					
						
							|  |  |  | 		return 0; | 
					
						
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							|  |  |  | 	cpuid = convert_apicid_to_cpu(apicid); | 
					
						
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							|  |  |  | 	return cpuid >= 0 ? cpuid : 0; | 
					
						
							|  |  |  | } | 
					
						
							|  |  |  | #endif
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