x86: create smpcommon.c

This patch creates smpcommon.c with functions that are
equal between architectures. The i386-only init_gdt
is ifdef'd.

Note that smpcommon.o figures twice in the Makefile:
this is because sub-architectures like voyager that does
not use the normal smp_$(BITS) files also have to access them

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/Makefile

@@ -47,8 +47,8 @@ obj-$(CONFIG_PCI)		+= early-quirks.o
 apm-y				:= apm_32.o
 obj-$(CONFIG_APM)		+= apm.o
 obj-$(CONFIG_X86_SMP)		+= smp_$(BITS).o smpboot_$(BITS).o smpboot.o tsc_sync.o
-obj-$(CONFIG_X86_32_SMP)	+= smpcommon_32.o
-obj-$(CONFIG_X86_64_SMP)	+= smp_64.o smpboot_64.o tsc_sync.o
+obj-$(CONFIG_X86_32_SMP)	+= smpcommon.o
+obj-$(CONFIG_X86_64_SMP)	+= smp_64.o smpboot_64.o tsc_sync.o smpcommon.o
 obj-$(CONFIG_X86_TRAMPOLINE)	+= trampoline_$(BITS).o
 obj-$(CONFIG_X86_MPPARSE)	+= mpparse_$(BITS).o
 obj-$(CONFIG_X86_LOCAL_APIC)	+= apic_$(BITS).o nmi_$(BITS).o

arch/x86/kernel/smp_64.c

@@ -401,62 +401,6 @@ int native_smp_call_function_mask(cpumask_t mask,
 	return ret;
 }
 
-/*
- * smp_call_function_single - Run a function on a specific CPU
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @nonatomic: Currently unused.
- * @wait: If true, wait until function has completed on other CPUs.
- *
- * Retrurns 0 on success, else a negative status code.
- *
- * Does not return until the remote CPU is nearly ready to execute <func>
- * or is or has executed.
- */
-
-int smp_call_function_single (int cpu, void (*func) (void *info), void *info,
-			      int nonatomic, int wait)
-{
-	/* prevent preemption and reschedule on another processor */
-	int ret, me = get_cpu();
-
-	if (cpu == me) {
-		local_irq_disable();
-		func(info);
-		local_irq_enable();
-		put_cpu();
-		return 0;
-	}
-
-	ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
-
-	put_cpu();
-	return ret;
-}
-EXPORT_SYMBOL(smp_call_function_single);
-
-/*
- * smp_call_function - run a function on all other CPUs.
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @nonatomic: currently unused.
- * @wait: If true, wait (atomically) until function has completed on other
- *        CPUs.
- *
- * Returns 0 on success, else a negative status code. Does not return until
- * remote CPUs are nearly ready to execute func or are or have executed.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
- * Actually there are a few legal cases, like panic.
- */
-int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
-			int wait)
-{
-	return smp_call_function_mask(cpu_online_map, func, info, wait);
-}
-EXPORT_SYMBOL(smp_call_function);
-
 static void stop_this_cpu(void *dummy)
 {
 	local_irq_disable();

arch/x86/kernel/smpcommon.c

@@ -0,0 +1,83 @@
+/*
+ * SMP stuff which is common to all sub-architectures.
+ */
+#include <linux/module.h>
+#include <asm/smp.h>
+
+#ifdef CONFIG_X86_32
+DEFINE_PER_CPU(unsigned long, this_cpu_off);
+EXPORT_PER_CPU_SYMBOL(this_cpu_off);
+
+/* Initialize the CPU's GDT.  This is either the boot CPU doing itself
+   (still using the master per-cpu area), or a CPU doing it for a
+   secondary which will soon come up. */
+__cpuinit void init_gdt(int cpu)
+{
+	struct desc_struct *gdt = get_cpu_gdt_table(cpu);
+
+	pack_descriptor(&gdt[GDT_ENTRY_PERCPU],
+			__per_cpu_offset[cpu], 0xFFFFF,
+			0x2 | DESCTYPE_S, 0x8);
+
+	gdt[GDT_ENTRY_PERCPU].s = 1;
+
+	per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
+	per_cpu(cpu_number, cpu) = cpu;
+}
+#endif
+
+/**
+ * smp_call_function(): Run a function on all other CPUs.
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @nonatomic: Unused.
+ * @wait: If true, wait (atomically) until function has completed on other CPUs.
+ *
+ * Returns 0 on success, else a negative status code.
+ *
+ * If @wait is true, then returns once @func has returned; otherwise
+ * it returns just before the target cpu calls @func.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
+		      int wait)
+{
+	return smp_call_function_mask(cpu_online_map, func, info, wait);
+}
+EXPORT_SYMBOL(smp_call_function);
+
+/**
+ * smp_call_function_single - Run a function on a specific CPU
+ * @cpu: The target CPU.  Cannot be the calling CPU.
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @nonatomic: Unused.
+ * @wait: If true, wait until function has completed on other CPUs.
+ *
+ * Returns 0 on success, else a negative status code.
+ *
+ * If @wait is true, then returns once @func has returned; otherwise
+ * it returns just before the target cpu calls @func.
+ */
+int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
+			     int nonatomic, int wait)
+{
+	/* prevent preemption and reschedule on another processor */
+	int ret;
+	int me = get_cpu();
+	if (cpu == me) {
+		local_irq_disable();
+		func(info);
+		local_irq_enable();
+		put_cpu();
+		return 0;
+	}
+
+	ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
+
+	put_cpu();
+	return ret;
+}
+EXPORT_SYMBOL(smp_call_function_single);

arch/x86/kernel/smpcommon_32.c

@@ -1,82 +1 @@
-/*
- * SMP stuff which is common to all sub-architectures.
- */
-#include <linux/module.h>
-#include <asm/smp.h>
 
-DEFINE_PER_CPU(unsigned long, this_cpu_off);
-EXPORT_PER_CPU_SYMBOL(this_cpu_off);
-
-/* Initialize the CPU's GDT.  This is either the boot CPU doing itself
-   (still using the master per-cpu area), or a CPU doing it for a
-   secondary which will soon come up. */
-__cpuinit void init_gdt(int cpu)
-{
-	struct desc_struct *gdt = get_cpu_gdt_table(cpu);
-
-	pack_descriptor(&gdt[GDT_ENTRY_PERCPU],
-			__per_cpu_offset[cpu], 0xFFFFF,
-			0x2 | DESCTYPE_S, 0x8);
-
-	gdt[GDT_ENTRY_PERCPU].s = 1;
-
-	per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
-	per_cpu(cpu_number, cpu) = cpu;
-}
-
-
-/**
- * smp_call_function(): Run a function on all other CPUs.
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @nonatomic: Unused.
- * @wait: If true, wait (atomically) until function has completed on other CPUs.
- *
- * Returns 0 on success, else a negative status code.
- *
- * If @wait is true, then returns once @func has returned; otherwise
- * it returns just before the target cpu calls @func.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
- */
-int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
-		      int wait)
-{
-	return smp_call_function_mask(cpu_online_map, func, info, wait);
-}
-EXPORT_SYMBOL(smp_call_function);
-
-/**
- * smp_call_function_single - Run a function on a specific CPU
- * @cpu: The target CPU.  Cannot be the calling CPU.
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @nonatomic: Unused.
- * @wait: If true, wait until function has completed on other CPUs.
- *
- * Returns 0 on success, else a negative status code.
- *
- * If @wait is true, then returns once @func has returned; otherwise
- * it returns just before the target cpu calls @func.
- */
-int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
-			     int nonatomic, int wait)
-{
-	/* prevent preemption and reschedule on another processor */
-	int ret;
-	int me = get_cpu();
-	if (cpu == me) {
-		local_irq_disable();
-		func(info);
-		local_irq_enable();
-		put_cpu();
-		return 0;
-	}
-
-	ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
-
-	put_cpu();
-	return ret;
-}
-EXPORT_SYMBOL(smp_call_function_single);