[PATCH 3.4 11/19] x86, espfix: Make espfix64 a Kconfig option, fix UML

Greg Kroah-Hartman
2014-08-05T18:34:56Z

From: "H. Peter Anvin" <hpa@zytor.com>

commit 197725de65477bc8509b41388157c1a2283542bb upstream.

Make espfix64 a hidden Kconfig option. This fixes the x86-64 UML
build which had broken due to the non-existence of init_espfix_bsp()
in UML: since UML uses its own Kconfig, this option does not appear in
the UML build.

This also makes it possible to make support for 16-bit segments a
configuration option, for the people who want to minimize the size of
the kernel.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/Kconfig | 4 ++++
arch/x86/kernel/Makefile | 2 +-
arch/x86/kernel/smpboot.c | 2 +-
init/main.c | 2 +-
4 files changed, 7 insertions(+), 3 deletions(-)

--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -920,6 +920,10 @@ config VM86
XFree86 to initialize some video cards via BIOS. Disabling this
option saves about 6k.

+config X86_ESPFIX64
+ def_bool y
+ depends on X86_64
+
config TOSHIBA
tristate "Toshiba Laptop support"
depends on X86_32
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -28,7 +28,7 @@ obj-$(CONFIG_X86_64) += sys_x86_64.o x86
obj-y += syscall_$(BITS).o
obj-$(CONFIG_X86_64) += vsyscall_64.o
obj-$(CONFIG_X86_64) += vsyscall_emu_64.o
-obj-$(CONFIG_X86_64) += espfix_64.o
+obj-$(CONFIG_X86_ESPFIX64) += espfix_64.o
obj-y += bootflag.o e820.o
obj-y += pci-dma.o quirks.o topology.o kdebugfs.o
obj-y += alternative.o i8253.o pci-nommu.o hw_breakpoint.o
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -273,7 +273,7 @@ notrace static void __cpuinit start_seco
/*
* Enable the espfix hack for this CPU
*/
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_ESPFIX64
init_espfix_ap();
#endif

--- a/init/main.c
+++ b/init/main.c
@@ -606,7 +606,7 @@ asmlinkage void __init start_kernel(void
if (efi_enabled(EFI_RUNTIME_SERVICES))
efi_enter_virtual_mode();
#endif
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_ESPFIX64
/* Should be run before the first non-init thread is created */
init_espfix_bsp();
#endif