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@kernel.org>
Cc: eric.dumazet@gmail.com
Cc: yinghai@kernel.org
Cc: brgerst@gmail.com
Cc: gorcunov@gmail.com
Cc: penberg@kernel.org
Cc: shaohui.zheng@intel.com
Cc: rientjes@google.com
LKML-Reference: <1295789862-25482-6-git-send-email-tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 15 insertions, 8 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 126d5a3b00e9..ae08246f320c 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1248,6 +1248,14 @@ 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 5037736c460d..cce91bf26676 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 df934e46bf53..ca20f6bee3be 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