linux-kernel - [PATCH 06/16] x86: Always use x86_cpu_to_logical

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Date:	Sat, 27 Nov 2010 16:21:55 +0100
From:	Tejun Heo <tj@...nel.org>
To:	linux-kernel@...r.kernel.org, mingo@...hat.com, tglx@...utronix.de,
	hpa@...or.com, x86@...nel.org, eric.dumazet@...il.com,
	yinghai@...nel.org, brgerst@...il.com, gorcunov@...il.com,
	penberg@...nel.org
Cc:	Tejun Heo <tj@...nel.org>
Subject: [PATCH 06/16] x86: Always use x86_cpu_to_logical_apicid for cpu -> logical apic id

Currently, cpu -> logical apic id translation is done by
apic->cpu_to_logical_apicid() callback which may or may not use
x86_cpu_to_logical_apicid.  This is unnecessary as it should always
equal logical_smp_processor_id() which is known early during CPU bring
up.

Initialize x86_cpu_to_logical_apicid after apic->init_apic_ldr() in
setup_local_APIC() and always use x86_cpu_to_logical_apicid for cpu ->
logical apic id mapping.

Signed-off-by: Tejun Heo <tj@...nel.org>
---
 arch/x86/kernel/apic/apic.c |    8 ++++++++
 arch/x86/kernel/apic/ipi.c  |    8 ++++----
 arch/x86/kernel/smpboot.c   |    7 +++----
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index f0919bc..543bc37 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1252,6 +1252,14 @@ void __cpuinit setup_local_APIC(void)
 	 */
 	apic->init_apic_ldr();
 
+#ifdef CONFIG_X86_32
+	/*
+	 * APIC LDR is initialized.  Fetch and store logical_apic_id.
+	 */
+	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
+		logical_smp_processor_id();
+#endif
+
 	/*
 	 * Set Task Priority to 'accept all'. We never change this
 	 * later on.
diff --git a/arch/x86/kernel/apic/ipi.c b/arch/x86/kernel/apic/ipi.c
index 5037736..cce91bf 100644
--- a/arch/x86/kernel/apic/ipi.c
+++ b/arch/x86/kernel/apic/ipi.c
@@ -73,8 +73,8 @@ void default_send_IPI_mask_sequence_logical(const struct cpumask *mask,
 	local_irq_save(flags);
 	for_each_cpu(query_cpu, mask)
 		__default_send_IPI_dest_field(
-			apic->cpu_to_logical_apicid(query_cpu), vector,
-			apic->dest_logical);
+			early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
+			vector, apic->dest_logical);
 	local_irq_restore(flags);
 }
 
@@ -92,8 +92,8 @@ void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask,
 		if (query_cpu == this_cpu)
 			continue;
 		__default_send_IPI_dest_field(
-			apic->cpu_to_logical_apicid(query_cpu), vector,
-			apic->dest_logical);
+			early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
+			vector, apic->dest_logical);
 		}
 	local_irq_restore(flags);
 }
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index eb04f30..0768761 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -168,19 +168,18 @@ static void unmap_cpu_to_node(int cpu)
 static void map_cpu_to_logical_apicid(void)
 {
 	int cpu = smp_processor_id();
-	int apicid = logical_smp_processor_id();
-	int node = apic->apicid_to_node(apicid);
+	int logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
+	int node;
 
+	node = apic->apicid_to_node(logical_apicid);
 	if (!node_online(node))
 		node = first_online_node;
 
-	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = apicid;
 	map_cpu_to_node(cpu, node);
 }
 
 void numa_remove_cpu(int cpu)
 {
-	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = BAD_APICID;
 	unmap_cpu_to_node(cpu);
 }
 #else
-- 
1.7.1

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