x86, realmode: header for trampoline code

Added header for trampoline code that can be used to supply
input data to it. This makes interface between real mode code
and kernel cleaner and simpler. Replaced two confusing pointers
to level4 pgt in trampoline_64.S with a single pointer to the
beginning of the page table.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-21-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/include/asm/realmode.h

@@ -8,24 +8,32 @@
 struct real_mode_header {
 	u32	text_start;
 	u32	ro_end;
-	/* reboot */
-#ifdef CONFIG_X86_32
-	u32	machine_real_restart_asm;
-#endif
 	/* SMP trampoline */
-	u32	trampoline_data;
+	u32	trampoline_start;
 	u32	trampoline_status;
-#ifdef CONFIG_X86_32
-	u32	startup_32_smp;
-	u32	boot_gdt;
-#else
-	u32	startup_64_smp;
-	u32	level3_ident_pgt;
-	u32	level3_kernel_pgt;
+	u32	trampoline_header;
+#ifdef CONFIG_X86_64
+	u32	trampoline_pgd;
 #endif
+	/* ACPI S3 wakeup */
 #ifdef CONFIG_ACPI_SLEEP
 	u32	wakeup_start;
 	u32	wakeup_header;
+#endif
+	/* APM/BIOS reboot */
+#ifdef CONFIG_X86_32
+	u32	machine_real_restart_asm;
+#endif
+} __attribute__((__packed__));
+
+/* This must match data at trampoline_32/64.S */
+struct trampoline_header {
+#ifdef CONFIG_X86_32
+	u32 start;
+	u16 gdt_limit;
+	u32 gdt_base;
+#else
+	u64 start;
 #endif
 } __attribute__((__packed__));