[PATCH 04/16] x86: Replace cpu_2_logical_apicid[] with early percpu variable

From: Tejun Heo
Date: Thu Dec 30 2010 - 12:52:35 EST


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@xxxxxxxxxx>
---
arch/x86/include/asm/apic.h | 4 ----
arch/x86/include/asm/smp.h | 3 +++
arch/x86/kernel/apic/apic.c | 11 +++++++++++
arch/x86/kernel/apic/es7000_32.c | 2 +-
arch/x86/kernel/apic/numaq_32.c | 2 +-
arch/x86/kernel/apic/summit_32.c | 4 ++--
arch/x86/kernel/setup_percpu.c | 7 +++++++
arch/x86/kernel/smpboot.c | 7 ++-----
8 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 5e3969c..eb139ec 100644
--- a/arch/x86/include/asm/apic.h
+++ b/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 */
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 4c2f63c..dc7c46a 100644
--- a/arch/x86/include/asm/smp.h
+++ b/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 {
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index c0f6426..ba78b1e 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -79,6 +79,17 @@ 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.
*
diff --git a/arch/x86/kernel/apic/es7000_32.c b/arch/x86/kernel/apic/es7000_32.c
index 8593582..7cb73e1 100644
--- a/arch/x86/kernel/apic/es7000_32.c
+++ b/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
diff --git a/arch/x86/kernel/apic/numaq_32.c b/arch/x86/kernel/apic/numaq_32.c
index 960f26a..4ed90c4 100644
--- a/arch/x86/kernel/apic/numaq_32.c
+++ b/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);
}

/*
diff --git a/arch/x86/kernel/apic/summit_32.c b/arch/x86/kernel/apic/summit_32.c
index 9b41926..82cfc3e 100644
--- a/arch/x86/kernel/apic/summit_32.c
+++ b/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
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 002b796..b5147f0 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/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
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 0b32f17..eb04f30 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/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
--
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/