Merge branch 'x86-trampoline-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 trampoline rework from H. Peter Anvin:
 "This code reworks all the "trampoline"/"realmode" code (various bits
  that need to live in the first megabyte of memory, most but not all of
  which runs in real mode at some point) in the kernel into a single
  object.  The main reason for doing this is that it eliminates the last
  place in the kernel where we needed pages to be mapped RWX.  This code
  separates all that code into proper R/RW/RX pages."

Fix up conflicts in arch/x86/kernel/Makefile (mca removed next to reboot
code), and arch/x86/kernel/reboot.c (reboot code moved around in one
branch, modified in this one), and arch/x86/tools/relocs.c (mostly same
code came in earlier due to working around the ld bugs just before the
3.4 release).

Also remove stale x86-relocs entry from scripts/.gitignore as per Peter
Anvin.

* commit '61f5446169046c217a5479517edac3a890c3bee7': (36 commits)
  x86, realmode: Move end signature into header.S
  x86, relocs: When printing an error, say relative or absolute
  x86, relocs: More relocations which may end up as absolute
  x86, relocs: Workaround for binutils 2.22.52.0.1 section bug
  xen-acpi-processor: Add missing #include <xen/xen.h>
  acpi, bgrd: Add missing <linux/io.h> to drivers/acpi/bgrt.c
  x86, realmode: Change EFER to a single u64 field
  x86, realmode: Move kernel/realmode.c to realmode/init.c
  x86, realmode: Move not-common bits out of trampoline_common.S
  x86, realmode: Mask out EFER.LMA when saving trampoline EFER
  x86, realmode: Fix no cache bits test in reboot_32.S
  x86, realmode: Make sure all generated files are listed in targets
  x86, realmode: build fix: remove duplicate build
  x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline
  x86, realmode: fixes compilation issue in tboot.c
  x86, realmode: move relocs from scripts/ to arch/x86/tools
  x86, realmode: header for trampoline code
  x86, realmode: flattened rm hierachy
  x86, realmode: don't copy real_mode_header
  x86, realmode: fix 64-bit wakeup sequence
  ...

1 files changed, 3 insertions, 22 deletions

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 77215c23fba1..79c45af81604 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -24,6 +24,7 @@
 #ifdef CONFIG_X86_32
 # include <linux/ctype.h>
 # include <linux/mc146818rtc.h>
+# include <asm/realmode.h>
 #else
 # include <asm/x86_init.h>
 #endif
@@ -156,15 +157,10 @@ static int __init set_bios_reboot(const struct dmi_system_id *d)
         return 0;
 }
 
-extern const unsigned char machine_real_restart_asm[];
-extern const u64 machine_real_restart_gdt[3];
-
 void machine_real_restart(unsigned int type)
 {
-        void *restart_va;
-        unsigned long restart_pa;
-        void (*restart_lowmem)(unsigned int);
-        u64 *lowmem_gdt;
+        void (*restart_lowmem)(unsigned int) = (void (*)(unsigned int))
+                real_mode_header->machine_real_restart_asm;
 
         local_irq_disable();
 
@@ -195,21 +191,6 @@ void machine_real_restart(unsigned int type)
          * too. */
         *((unsigned short *)0x472) = reboot_mode;
 
-        /* Patch the GDT in the low memory trampoline */
-        lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
-
-        restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
-        restart_pa = virt_to_phys(restart_va);
-        restart_lowmem = (void (*)(unsigned int))restart_pa;
-
-        /* GDT[0]: GDT self-pointer */
-        lowmem_gdt[0] =
-                (u64)(sizeof(machine_real_restart_gdt) - 1) +
-                ((u64)virt_to_phys(lowmem_gdt) << 16);
-        /* GDT[1]: 64K real mode code segment */
-        lowmem_gdt[1] =
-                GDT_ENTRY(0x009b, restart_pa, 0xffff);
-
         /* Jump to the identity-mapped low memory code */
         restart_lowmem(type);
 }