x86: Replace cpu_2_logical_apicid[] with early percpu variable

Unlike x86_64, on x86_32, the mapping from cpu to logical apicid
may vary depending on apic in use.  cpu_2_logical_apicid[] array
is used for this mapping.  Replace it with early percpu variable
x86_cpu_to_logical_apicid to make it better aligned with other
mappings.
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: <1295789862-25482-5-git-send-email-tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/apic.h

@@ -595,8 +595,4 @@ extern int default_check_phys_apicid_present(int phys_apicid);
 
 #endif /* CONFIG_X86_LOCAL_APIC */
 
-#ifdef CONFIG_X86_32
-extern u8 cpu_2_logical_apicid[NR_CPUS];
-#endif
-
 #endif /* _ASM_X86_APIC_H */

arch/x86/include/asm/smp.h

@@ -38,6 +38,9 @@ static inline struct cpumask *cpu_core_mask(int cpu)
 
 DECLARE_EARLY_PER_CPU(u16, x86_cpu_to_apicid);
 DECLARE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid);
+#if defined(CONFIG_SMP) && defined(CONFIG_X86_32)
+DECLARE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid);
+#endif
 
 /* Static state in head.S used to set up a CPU */
 extern struct {

arch/x86/kernel/apic/apic.c

@@ -78,6 +78,17 @@ EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
 
 #ifdef CONFIG_X86_32
+
+#ifdef CONFIG_SMP
+/*
+ * On x86_32, the mapping between cpu and logical apicid may vary
+ * depending on apic in use.  The following early percpu variable is
+ * used for the mapping.  This is where the behaviors of x86_64 and 32
+ * actually diverge.  Let's keep it ugly for now.
+ */
+DEFINE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid, BAD_APICID);
+#endif
+
 /*
  * Knob to control our willingness to enable the local APIC.
  *

arch/x86/kernel/apic/es7000_32.c

@@ -534,7 +534,7 @@ static int es7000_cpu_to_logical_apicid(int cpu)
 #ifdef CONFIG_SMP
 	if (cpu >= nr_cpu_ids)
 		return BAD_APICID;
-	return cpu_2_logical_apicid[cpu];
+	return early_per_cpu(x86_cpu_to_logical_apicid, cpu);
 #else
 	return logical_smp_processor_id();
 #endif

arch/x86/kernel/apic/numaq_32.c

@@ -377,7 +377,7 @@ static inline int numaq_cpu_to_logical_apicid(int cpu)
 {
 	if (cpu >= nr_cpu_ids)
 		return BAD_APICID;
-	return cpu_2_logical_apicid[cpu];
+	return early_per_cpu(x86_cpu_to_logical_apicid, cpu);
 }
 
 /*

arch/x86/kernel/apic/summit_32.c

@@ -206,7 +206,7 @@ static void summit_init_apic_ldr(void)
 
 	/* Create logical APIC IDs by counting CPUs already in cluster. */
 	for (count = 0, i = nr_cpu_ids; --i >= 0; ) {
-		lid = cpu_2_logical_apicid[i];
+		lid = early_per_cpu(x86_cpu_to_logical_apicid, i);
 		if (lid != BAD_APICID && APIC_CLUSTER(lid) == my_cluster)
 			++count;
 	}
@@ -247,7 +247,7 @@ static inline int summit_cpu_to_logical_apicid(int cpu)
 #ifdef CONFIG_SMP
 	if (cpu >= nr_cpu_ids)
 		return BAD_APICID;
-	return cpu_2_logical_apicid[cpu];
+	return early_per_cpu(x86_cpu_to_logical_apicid, cpu);
 #else
 	return logical_smp_processor_id();
 #endif

arch/x86/kernel/setup_percpu.c

@@ -225,6 +225,10 @@ void __init setup_per_cpu_areas(void)
 		per_cpu(x86_bios_cpu_apicid, cpu) =
 			early_per_cpu_map(x86_bios_cpu_apicid, cpu);
 #endif
+#ifdef CONFIG_X86_32
+		per_cpu(x86_cpu_to_logical_apicid, cpu) =
+			early_per_cpu_map(x86_cpu_to_logical_apicid, cpu);
+#endif
 #ifdef CONFIG_X86_64
 		per_cpu(irq_stack_ptr, cpu) =
 			per_cpu(irq_stack_union.irq_stack, cpu) +
@@ -256,6 +260,9 @@ void __init setup_per_cpu_areas(void)
 	early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
 	early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
 #endif
+#ifdef CONFIG_X86_32
+	early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;
+#endif
 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
 	early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
 #endif

arch/x86/kernel/smpboot.c

@@ -165,9 +165,6 @@ static void unmap_cpu_to_node(int cpu)
 #endif
 
 #ifdef CONFIG_X86_32
-u8 cpu_2_logical_apicid[NR_CPUS] __read_mostly =
-					{ [0 ... NR_CPUS-1] = BAD_APICID };
-
 static void map_cpu_to_logical_apicid(void)
 {
 	int cpu = smp_processor_id();
@@ -177,13 +174,13 @@ static void map_cpu_to_logical_apicid(void)
 	if (!node_online(node))
 		node = first_online_node;
 
-	cpu_2_logical_apicid[cpu] = apicid;
+	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = apicid;
 	map_cpu_to_node(cpu, node);
 }
 
 void numa_remove_cpu(int cpu)
 {
-	cpu_2_logical_apicid[cpu] = BAD_APICID;
+	early_per_cpu(x86_cpu_to_logical_apicid, cpu) = BAD_APICID;
 	unmap_cpu_to_node(cpu);
 }
 #else