i386: move common parts of smp into their own file

Several parts of kernel/smp.c and smpboot.c are generally useful for other
subarchitectures and paravirt_ops implementations, so make them available for
reuse.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/arch/i386/kernel/smpcommon.c b/arch/i386/kernel/smpcommon.c
new file mode 100644
index 000000000000..1868ae18eb4d
--- /dev/null
+++ b/arch/i386/kernel/smpcommon.c
@@ -0,0 +1,79 @@
+/*
+ * 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((u32 *)&gdt[GDT_ENTRY_PERCPU].a,
+                        (u32 *)&gdt[GDT_ENTRY_PERCPU].b,
+                        __per_cpu_offset[cpu], 0xFFFFF,
+                        0x80 | DESCTYPE_S | 0x2, 0x8);
+
+        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 another 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) {
+                WARN_ON(1);
+                put_cpu();
+                return -EBUSY;
+        }
+
+        ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
+
+        put_cpu();
+        return ret;
+}
+EXPORT_SYMBOL(smp_call_function_single);