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DateSun, 22 Dec 2002 23:00:45 -0800
From"Martin J. Bligh" <>
Subject[PATCH] 7/8 Move NUMA-Q support into subarch
This one fixes up the IPI code to do something more sensible. 
Sorry, was just too ugly to leave it alone ... but I did keep
it seperated out ;-) Though this is not an equivalent transform
it will only affect NUMA-Q & summit  - same op twice because some
twit just split it out in the last patch for both NUMA-Q & Summit.

Because clustered apic logical mode can't do arbitrary broadcasts
of addressing (it's not just a bitmap), I have to do send IPI 
instructions as a sequence of unicasts. However, there's already
a loop in the generic send_IPI_mask code to do that ... there's
no need to call send_IPI_mask once for each CPU. The comment I
wrote at the time even noted that this was silly.

diff -urpN -X /home/fletch/.diff.exclude 15-numaq5/include/asm-i386/mach-numaq/mach_ipi.h 16-numaq6/include/asm-i386/mach-numaq/mach_ipi.h
--- 15-numaq5/include/asm-i386/mach-numaq/mach_ipi.h	Sun Dec 22 12:11:09 2002
+++ 16-numaq6/include/asm-i386/mach-numaq/mach_ipi.h	Sun Dec 22 12:11:34 2002
@@ -10,30 +10,15 @@ static inline void send_IPI_mask(int mas
 
 static inline void send_IPI_allbutself(int vector)
 {
-	int cpu;
-	/*
-	 * 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;
+	unsigned long mask = cpu_online_map & ~(1 << smp_processor_id());
 
-	/* Pointless. Use send_IPI_mask to do this instead */
-	for (cpu = 0; cpu < NR_CPUS; ++cpu)
-		if (cpu_online(cpu) && cpu != smp_processor_id())
-			send_IPI_mask(1 << cpu, vector);
-
-	return;
+	if (mask)
+		send_IPI_mask(mask, vector);
 }
 
 static inline void send_IPI_all(int vector)
 {
-	int cpu;
-
-	/* Pointless. Use send_IPI_mask to do this instead */
-	for (cpu = 0; cpu < NR_CPUS; ++cpu)
-		if (cpu_online(cpu))
-			send_IPI_mask(1 << cpu, vector);
+	send_IPI_mask(cpu_online_map, vector);
 }
 
 #endif /* __ASM_MACH_IPI_H */
diff -urpN -X /home/fletch/.diff.exclude 15-numaq5/include/asm-i386/mach-summit/mach_ipi.h 16-numaq6/include/asm-i386/mach-summit/mach_ipi.h
--- 15-numaq5/include/asm-i386/mach-summit/mach_ipi.h	Sun Dec 22 12:11:09 2002
+++ 16-numaq6/include/asm-i386/mach-summit/mach_ipi.h	Sun Dec 22 12:11:34 2002
@@ -10,30 +10,15 @@ static inline void send_IPI_mask(int mas
 
 static inline void send_IPI_allbutself(int vector)
 {
-	int cpu;
-	/*
-	 * 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;
+	unsigned long mask = cpu_online_map & ~(1 << smp_processor_id());
 
-	/* Pointless. Use send_IPI_mask to do this instead */
-	for (cpu = 0; cpu < NR_CPUS; ++cpu)
-		if (cpu_online(cpu) && cpu != smp_processor_id())
-			send_IPI_mask(1 << cpu, vector);
-
-	return;
+	if (mask)
+		send_IPI_mask(mask, vector);
 }
 
 static inline void send_IPI_all(int vector)
 {
-	int cpu;
-
-	/* Pointless. Use send_IPI_mask to do this instead */
-	for (cpu = 0; cpu < NR_CPUS; ++cpu)
-		if (cpu_online(cpu))
-			send_IPI_mask(1 << cpu, vector);
+	send_IPI_mask(cpu_online_map, vector);
 }
 
 #endif /* __ASM_MACH_IPI_H */
-
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