x86: Store the GDT pointer in global_data

When we start up additional CPUs we want them to use the same Global
Descriptor Table. Store the address of this in global_data so we can
reference it later.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/cpu.c

@@ -133,6 +133,7 @@ static void load_gdt(const u64 *boot_gdt, u16 num_entries)
 
 void setup_gdt(gd_t *id, u64 *gdt_addr)
 {
+	id->arch.gdt = gdt_addr;
 	/* CS: code, read/execute, 4 GB, base 0 */
 	gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
 

arch/x86/include/asm/global_data.h

@@ -68,6 +68,7 @@ struct arch_global_data {
 	/* MRC training data to save for the next boot */
 	char *mrc_output;
 	unsigned int mrc_output_len;
+	void *gdt;			/* Global descriptor table */
 };
 
 #endif