x86: Move the GDT into global_data

Rather than keeping track of the Global Descriptor Table in its own memory
we may as well put it in global_data with everything else. As a first step,
stop using the separately allocated GDT.

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

arch/x86/cpu/cpu.c

@@ -136,9 +136,10 @@ static void load_gdt(const u64 *boot_gdt, u16 num_entries)
 	asm volatile("lgdtl %0\n" : : "m" (gdt));
 }
 
-void setup_gdt(gd_t *id, u64 *gdt_addr)
+void setup_gdt(gd_t *new_gd, u64 *gdt_addr)
 {
-	id->arch.gdt = gdt_addr;
+	gdt_addr = new_gd->arch.gdt;
+
 	/* CS: code, read/execute, 4 GB, base 0 */
 	gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
 
@@ -146,9 +147,9 @@ void setup_gdt(gd_t *id, u64 *gdt_addr)
 	gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
 
 	/* FS: data, read/write, 4 GB, base (Global Data Pointer) */
-	id->arch.gd_addr = id;
+	new_gd->arch.gd_addr = new_gd;
 	gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
-		     (ulong)&id->arch.gd_addr, 0xfffff);
+		     (ulong)&new_gd->arch.gd_addr, 0xfffff);
 
 	/* 16-bit CS: code, read/execute, 64 kB, base 0 */
 	gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x009b, 0, 0x0ffff);

arch/x86/include/asm/global_data.h

@@ -10,6 +10,8 @@
 
 #ifndef __ASSEMBLY__
 
+#include <asm/processor.h>
+
 enum pei_boot_mode_t {
 	PEI_BOOT_NONE = 0,
 	PEI_BOOT_SOFT_RESET,
@@ -44,6 +46,7 @@ struct mtrr_request {
 
 /* Architecture-specific global data */
 struct arch_global_data {
+	u64 gdt[X86_GDT_NUM_ENTRIES] __aligned(16);
 	struct global_data *gd_addr;	/* Location of Global Data */
 	uint8_t x86;			/* CPU family */
 	uint8_t x86_vendor;		/* CPU vendor */
@@ -68,7 +71,6 @@ 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 */
 	ulong table;			/* Table pointer from previous loader */
 };