uml: throw out CONFIG_MODE_TT

This patchset throws out tt mode, which has been non-functional for a while.

This is done in phases, interspersed with code cleanups on the affected files.

The removal is done as follows:
	remove all code, config options, and files which depend on
CONFIG_MODE_TT
	get rid of the CHOOSE_MODE macro, which decided whether to
call tt-mode or skas-mode code, and replace invocations with their
skas portions
	replace all now-trivial procedures with their skas equivalents

There are now a bunch of now-redundant pieces of data structures, including
mode-specific pieces of the thread structure, pt_regs, and mm_context.  These
are all replaced with their skas-specific contents.

As part of the ongoing style compliance project, I made a style pass over all
files that were changed.  There are three such patches, one for each phase,
covering the files affected by that phase but no later ones.

I noticed that we weren't freeing the LDT state associated with a process when
it exited, so that's fixed in one of the later patches.

The last patch is a tidying patch which I've had for a while, but which caused
inexplicable crashes under tt mode.  Since that is no longer a problem, this
can now go in.

This patch:

Start getting rid of tt mode support.

This patch throws out CONFIG_MODE_TT and all config options, code, and files
which depend on it.

CONFIG_MODE_SKAS is gone and everything that depends on it is included
unconditionally.

The few changed lines are in re-written Kconfig help, lines which needed
something skas-related removed from them, and a few more which weren't
strictly deletions.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/Makefile b/arch/um/Makefile
index 3efc4ff..e7aa053 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -31,18 +31,9 @@
 ARCH_SYMLINKS = include/asm-um/arch $(ARCH_DIR)/include/sysdep $(ARCH_DIR)/os \
 	$(SYMLINK_HEADERS) $(ARCH_DIR)/include/uml-config.h
 
-um-modes-$(CONFIG_MODE_TT) += tt
-um-modes-$(CONFIG_MODE_SKAS) += skas
+MODE_INCLUDE	+= -I$(srctree)/$(ARCH_DIR)/include/skas
 
-MODE_INCLUDE	+= $(foreach mode,$(um-modes-y),\
-		   -I$(srctree)/$(ARCH_DIR)/include/$(mode))
-
-MAKEFILES-INCL	+= $(foreach mode,$(um-modes-y),\
-		   $(srctree)/$(ARCH_DIR)/Makefile-$(mode))
-
-ifneq ($(MAKEFILES-INCL),)
-  include $(MAKEFILES-INCL)
-endif
+include $(srctree)/$(ARCH_DIR)/Makefile-skas
 
 ARCH_INCLUDE	:= -I$(ARCH_DIR)/include
 ifneq ($(KBUILD_SRC),)
@@ -89,9 +80,8 @@
 # included; the values here are meaningless
 
 CONFIG_NEST_LEVEL ?= 0
-CONFIG_KERNEL_HALF_GIGS ?= 0
 
-SIZE = (($(CONFIG_NEST_LEVEL) + $(CONFIG_KERNEL_HALF_GIGS)) * 0x20000000)
+SIZE = ($(CONFIG_NEST_LEVEL) * 0x20000000)
 
 PHONY += linux
 
@@ -124,7 +114,6 @@
 	$(call cc-option, -fno-stack-protector,) \
 	$(call cc-option, -fno-stack-protector-all,)
 
-CPP_MODE-$(CONFIG_MODE_TT) := -DMODE_TT
 CONFIG_KERNEL_STACK_ORDER ?= 2
 STACK_SIZE := $(shell echo $$[ 4096 * (1 << $(CONFIG_KERNEL_STACK_ORDER)) ] )
 
@@ -132,11 +121,8 @@
   START = $(shell echo $$[ $(TOP_ADDR) - $(SIZE) ] )
 endif
 
-CPPFLAGS_vmlinux.lds = -U$(SUBARCH) \
-	-DSTART=$(START) -DELF_ARCH=$(ELF_ARCH) \
-	-DELF_FORMAT="$(ELF_FORMAT)" $(CPP_MODE-y) \
-	-DKERNEL_STACK_SIZE=$(STACK_SIZE) \
-	-DUNMAP_PATH=arch/um/sys-$(SUBARCH)/unmap.o
+CPPFLAGS_vmlinux.lds = -U$(SUBARCH) -DSTART=$(START) -DELF_ARCH=$(ELF_ARCH) \
+	-DELF_FORMAT="$(ELF_FORMAT)" -DKERNEL_STACK_SIZE=$(STACK_SIZE)
 
 #The wrappers will select whether using "malloc" or the kernel allocator.
 LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc