[PATCH] x86: fix broken SMP boot sequence

Recent GDT changes broke the SMP boot sequence if the booting CPU is
numbered anything other than zero.  There's also a subtle source of error
in that the boot time CPU now uses cpu_gdt_table (which is actually the GDT
for booting CPUs in head.S).  This patch fixes both problems by making GDT
descriptors themselves allocated from a per_cpu area and switching to them
in cpu_init(), which now means that cpu_gdt_table is exclusively used for
booting CPUs again.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Matt Tolentino <metolent@snoqualmie.dp.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/i386/kernel/efi.c b/arch/i386/kernel/efi.c
index ecad519fd395..e3e42fd62401 100644
--- a/arch/i386/kernel/efi.c
+++ b/arch/i386/kernel/efi.c
@@ -103,17 +103,19 @@ static void efi_call_phys_prelog(void)
          */
         local_flush_tlb();
 
-        cpu_gdt_descr[0].address = __pa(cpu_gdt_descr[0].address);
-        load_gdt((struct Xgt_desc_struct *) __pa(&cpu_gdt_descr[0]));
+        per_cpu(cpu_gdt_descr, 0).address =
+                                 __pa(per_cpu(cpu_gdt_descr, 0).address);
+        load_gdt((struct Xgt_desc_struct *)__pa(&per_cpu(cpu_gdt_descr, 0)));
 }
 
 static void efi_call_phys_epilog(void)
 {
         unsigned long cr4;
 
-        cpu_gdt_descr[0].address =
-                (unsigned long) __va(cpu_gdt_descr[0].address);
-        load_gdt(&cpu_gdt_descr[0]);
+        per_cpu(cpu_gdt_descr, 0).address =
+                        (unsigned long)__va(per_cpu(cpu_gdt_descr, 0).address);
+        load_gdt((struct Xgt_desc_struct *)__va(&per_cpu(cpu_gdt_descr, 0)));
+
         cr4 = read_cr4();
 
         if (cr4 & X86_CR4_PSE) {