summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/smpcommon.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/smpcommon.c')
-rw-r--r--arch/x86/kernel/smpcommon.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/x86/kernel/smpcommon.c b/arch/x86/kernel/smpcommon.c
new file mode 100644
index 000000000000..3449064d141a
--- /dev/null
+++ b/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);