x86: initialize per-cpu GDT segment in per-cpu setup

Impact: cleanup

Rename init_gdt() to setup_percpu_segment(), and move it to
setup_percpu.c.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 599dc1cc1da8..bcca3a7b3748 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -40,6 +40,19 @@ unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
 };
 EXPORT_SYMBOL(__per_cpu_offset);
 
+static inline void setup_percpu_segment(int cpu)
+{
+#ifdef CONFIG_X86_32
+        struct desc_struct gdt;
+
+        pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
+                        0x2 | DESCTYPE_S, 0x8);
+        gdt.s = 1;
+        write_gdt_entry(get_cpu_gdt_table(cpu),
+                        GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
+#endif
+}
+
 /*
  * Great future plan:
  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
@@ -81,6 +94,7 @@ void __init setup_per_cpu_areas(void)
                 per_cpu_offset(cpu) = ptr - __per_cpu_start;
                 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
                 per_cpu(cpu_number, cpu) = cpu;
+                setup_percpu_segment(cpu);
                 /*
                  * Copy data used in early init routines from the initial arrays to the
                  * per cpu data areas.  These arrays then become expendable and the