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>

1 files changed, 20 insertions, 12 deletions

diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h
index d3ae49f4c3ef..1421eed1c8e8 100644
--- a/arch/x86/include/asm/realmode.h
+++ b/arch/x86/include/asm/realmode.h
@@ -8,25 +8,33 @@
 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__));
 
 extern struct real_mode_header *real_mode_header;