uml: remove code made redundant by CHOOSE_MODE removal

This patch makes a number of simplifications enabled by the removal of
CHOOSE_MODE.  There were lots of functions that looked like

	int foo(args){
		foo_skas(args);
	}

The bodies of foo_skas are now folded into foo, and their declarations (and
sometimes entire header files) are deleted.

In addition, the union uml_pt_regs, which was a union between the tt and skas
register formats, is now a struct, with the tt-mode arm of the union being
removed.

It turns out that usr2_handler was unused, so it is gone.

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>

19 files changed, 309 insertions, 435 deletions

diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index 8f774c25b76..5064fb691eb 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -18,17 +18,31 @@
 #include "irq_user.h"
 #include "tlb.h"
 #include "os.h"
-#include "mode_kern.h"
+#include "skas/skas.h"
 
 void flush_thread(void)
 {
+	void *data = NULL;
+	unsigned long end = proc_mm ? task_size : CONFIG_STUB_START;
+	int ret;
+
 	arch_flush_thread(&current->thread.arch);
-	flush_thread_skas();
+
+	ret = unmap(&current->mm->context.skas.id, 0, end, 1, &data);
+	if(ret){
+		printk("flush_thread - clearing address space failed, "
+		       "err = %d\n", ret);
+		force_sig(SIGKILL, current);
+	}
+
+	__switch_mm(&current->mm->context.skas.id);
 }
 
 void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
 {
-	start_thread_skas(regs, eip, esp);
+	set_fs(USER_DS);
+	PT_REGS_IP(regs) = eip;
+	PT_REGS_SP(regs) = esp;
 }
 
 #ifdef CONFIG_TTY_LOG
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index ec1ed680032..b10ee28b97c 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -91,7 +91,7 @@ static struct irq_fd **last_irq_ptr = &active_fds;
 
 extern void free_irqs(void);
 
-void sigio_handler(int sig, union uml_pt_regs *regs)
+void sigio_handler(int sig, struct uml_pt_regs *regs)
 {
 	struct irq_fd *irq_fd;
 	int n;
@@ -344,7 +344,7 @@ int deactivate_all_fds(void)
  * SMP cross-CPU interrupts have their own specific
  * handlers).
  */
-unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
+unsigned int do_IRQ(int irq, struct uml_pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs((struct pt_regs *)regs);
 	irq_enter();
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index f7b2f359479..90e89e83817 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -10,7 +10,7 @@
 #include "as-layout.h"
 #include "init.h"
 #include "kern.h"
-#include "mode_kern.h"
+#include "mem_user.h"
 #include "os.h"
 
 static int physmem_fd = -1;
@@ -61,7 +61,7 @@ static unsigned long kmem_top = 0;
 unsigned long get_kmem_end(void)
 {
 	if (kmem_top == 0)
-		kmem_top = kmem_end_skas;
+		kmem_top = host_task_size - 1024 * 1024;
 	return kmem_top;
 }
 
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 22ad46fd2c0..d3b9c62e73c 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -43,8 +43,7 @@
 #include "frame_kern.h"
 #include "sigcontext.h"
 #include "os.h"
-#include "mode.h"
-#include "mode_kern.h"
+#include "skas.h"
 
 /* This is a per-cpu array.  A processor only modifies its entry and it only
  * cares about its entry, so it's OK if another processor is modifying its
@@ -54,7 +53,8 @@ struct cpu_task cpu_tasks[NR_CPUS] = { [0 ... NR_CPUS - 1] = { -1, NULL } };
 
 static inline int external_pid(struct task_struct *task)
 {
-	return external_pid_skas(task);
+	/* FIXME: Need to look up userspace_pid by cpu */
+	return(userspace_pid[0]);
 }
 
 int pid_to_processor_id(int pid)
@@ -104,6 +104,8 @@ static inline void set_current(struct task_struct *task)
 		{ external_pid(task), task });
 }
 
+extern void arch_switch_to(struct task_struct *from, struct task_struct *to);
+
 void *_switch_to(void *prev, void *next, void *last)
 {
 	struct task_struct *from = prev;
@@ -114,7 +116,19 @@ void *_switch_to(void *prev, void *next, void *last)
 
 	do {
 		current->thread.saved_task = NULL;
-		switch_to_skas(prev, next);
+
+		/* XXX need to check runqueues[cpu].idle */
+		if(current->pid == 0)
+			switch_timers(0);
+
+		switch_threads(&from->thread.switch_buf,
+			       &to->thread.switch_buf);
+
+		arch_switch_to(current->thread.prev_sched, current);
+
+		if(current->pid == 0)
+			switch_timers(1);
+
 		if(current->thread.saved_task)
 			show_regs(&(current->thread.regs));
 		next= current->thread.saved_task;
@@ -133,11 +147,6 @@ void interrupt_end(void)
 		do_signal();
 }
 
-void release_thread(struct task_struct *task)
-{
-	release_thread_skas(task);
-}
-
 void exit_thread(void)
 {
 }
@@ -147,27 +156,95 @@ void *get_current(void)
 	return current;
 }
 
+extern void schedule_tail(struct task_struct *prev);
+
+/* This is called magically, by its address being stuffed in a jmp_buf
+ * and being longjmp-d to.
+ */
+void new_thread_handler(void)
+{
+	int (*fn)(void *), n;
+	void *arg;
+
+	if(current->thread.prev_sched != NULL)
+		schedule_tail(current->thread.prev_sched);
+	current->thread.prev_sched = NULL;
+
+	fn = current->thread.request.u.thread.proc;
+	arg = current->thread.request.u.thread.arg;
+
+	/* The return value is 1 if the kernel thread execs a process,
+	 * 0 if it just exits
+	 */
+	n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
+	if(n == 1){
+		/* Handle any immediate reschedules or signals */
+		interrupt_end();
+		userspace(&current->thread.regs.regs);
+	}
+	else do_exit(0);
+}
+
+/* Called magically, see new_thread_handler above */
+void fork_handler(void)
+{
+	force_flush_all();
+	if(current->thread.prev_sched == NULL)
+		panic("blech");
+
+	schedule_tail(current->thread.prev_sched);
+
+	/* XXX: if interrupt_end() calls schedule, this call to
+	 * arch_switch_to isn't needed. We could want to apply this to
+	 * improve performance. -bb */
+	arch_switch_to(current->thread.prev_sched, current);
+
+	current->thread.prev_sched = NULL;
+
+	/* Handle any immediate reschedules or signals */
+	interrupt_end();
+
+	userspace(&current->thread.regs.regs);
+}
+
 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 		unsigned long stack_top, struct task_struct * p,
 		struct pt_regs *regs)
 {
-	int ret;
+	void (*handler)(void);
+	int ret = 0;
 
 	p->thread = (struct thread_struct) INIT_THREAD;
-	ret = copy_thread_skas(nr, clone_flags, sp, stack_top, p, regs);
 
-	if (ret || !current->thread.forking)
-		goto out;
+	if(current->thread.forking){
+	  	memcpy(&p->thread.regs.regs, &regs->regs,
+		       sizeof(p->thread.regs.regs));
+		REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.regs, 0);
+		if(sp != 0)
+			REGS_SP(p->thread.regs.regs.regs) = sp;
 
-	clear_flushed_tls(p);
+		handler = fork_handler;
 
-	/*
-	 * Set a new TLS for the child thread?
-	 */
-	if (clone_flags & CLONE_SETTLS)
-		ret = arch_copy_tls(p);
+		arch_copy_thread(&current->thread.arch, &p->thread.arch);
+	}
+	else {
+		init_thread_registers(&p->thread.regs.regs);
+		p->thread.request.u.thread = current->thread.request.u.thread;
+		handler = new_thread_handler;
+	}
+
+	new_thread(task_stack_page(p), &p->thread.switch_buf, handler);
+
+	if (current->thread.forking) {
+		clear_flushed_tls(p);
+
+		/*
+		 * Set a new TLS for the child thread?
+		 */
+		if (clone_flags & CLONE_SETTLS)
+			ret = arch_copy_tls(p);
+	}
 
-out:
 	return ret;
 }
 
@@ -198,7 +275,8 @@ void default_idle(void)
 
 void cpu_idle(void)
 {
-	init_idle_skas();
+	cpu_tasks[current_thread->cpu].pid = os_getpid();
+	default_idle();
 }
 
 void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index 36debc0de59..bbc3a4a9a0f 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -228,7 +228,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 #ifdef PTRACE_ARCH_PRCTL
         case PTRACE_ARCH_PRCTL:
                 /* XXX Calls ptrace on the host - needs some SMP thinking */
-                ret = arch_prctl_skas(child, data, (void *) addr);
+                ret = arch_prctl(child, data, (void *) addr);
                 break;
 #endif
 	default:
@@ -239,7 +239,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 	return ret;
 }
 
-void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs,
+void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
 		  int error_code)
 {
 	struct siginfo info;
@@ -258,7 +258,7 @@ void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs,
 /* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and
  * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
  */
-void syscall_trace(union uml_pt_regs *regs, int entryexit)
+void syscall_trace(struct uml_pt_regs *regs, int entryexit)
 {
 	int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit;
 	int tracesysgood;
diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index 4a0def32e32..f3bd18bbf07 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -9,13 +9,30 @@
 #include "kern_util.h"
 #include "kern.h"
 #include "os.h"
-#include "mode.h"
+#include "skas.h"
 
 void (*pm_power_off)(void);
 
 static void kill_off_processes(void)
 {
-	kill_off_processes_skas();
+	if(proc_mm)
+		/*
+		 * FIXME: need to loop over userspace_pids
+		 */
+		os_kill_ptraced_process(userspace_pid[0], 1);
+	else {
+		struct task_struct *p;
+		int pid, me;
+
+		me = os_getpid();
+		for_each_process(p){
+			if(p->mm == NULL)
+				continue;
+
+			pid = p->mm->context.skas.id.u.pid;
+			os_kill_ptraced_process(pid, 1);
+		}
+	}
 }
 
 void uml_cleanup(void)
diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
index c4020c3d785..4dab7e417ba 100644
--- a/arch/um/kernel/signal.c
+++ b/arch/um/kernel/signal.c
@@ -23,7 +23,6 @@
 #include "kern.h"
 #include "frame_kern.h"
 #include "sigcontext.h"
-#include "mode.h"
 
 EXPORT_SYMBOL(block_signals);
 EXPORT_SYMBOL(unblock_signals);
diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
index 3e3fa7e7e3c..b2823cdd783 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -3,7 +3,7 @@
 # Licensed under the GPL
 #
 
-obj-y := clone.o exec.o mem.o mmu.o process.o syscall.o tlb.o uaccess.o
+obj-y := clone.o mmu.o process.o syscall.o uaccess.o
 
 # clone.o is in the stub, so it can't be built with profiling
 # GCC hardened also auto-enables -fpic, but we need %ebx so it can't work ->
diff --git a/arch/um/kernel/skas/exec.c b/arch/um/kernel/skas/exec.c
deleted file mode 100644
index 580eb646894..00000000000
--- a/arch/um/kernel/skas/exec.c
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include "linux/kernel.h"
-#include "asm/current.h"
-#include "asm/page.h"
-#include "asm/signal.h"
-#include "asm/ptrace.h"
-#include "asm/uaccess.h"
-#include "asm/mmu_context.h"
-#include "tlb.h"
-#include "skas.h"
-#include "um_mmu.h"
-#include "os.h"
-
-void flush_thread_skas(void)
-{
-	void *data = NULL;
-	unsigned long end = proc_mm ? task_size : CONFIG_STUB_START;
-	int ret;
-
-	ret = unmap(&current->mm->context.skas.id, 0, end, 1, &data);
-	if(ret){
-		printk("flush_thread_skas - clearing address space failed, "
-		       "err = %d\n", ret);
-		force_sig(SIGKILL, current);
-	}
-
-	switch_mm_skas(&current->mm->context.skas.id);
-}
-
-void start_thread_skas(struct pt_regs *regs, unsigned long eip,
-		       unsigned long esp)
-{
-	set_fs(USER_DS);
-	PT_REGS_IP(regs) = eip;
-	PT_REGS_SP(regs) = esp;
-}
diff --git a/arch/um/kernel/skas/mem.c b/arch/um/kernel/skas/mem.c
deleted file mode 100644
index 7c18dfcd7d8..00000000000
--- a/arch/um/kernel/skas/mem.c
+++ /dev/null
@@ -1,22 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Licensed under the GPL
- */
-
-#include "linux/mm.h"
-#include "asm/pgtable.h"
-#include "mem_user.h"
-#include "skas.h"
-
-unsigned long set_task_sizes_skas(unsigned long *task_size_out)
-{
-	/* Round up to the nearest 4M */
-	unsigned long host_task_size = ROUND_4M((unsigned long)
-						&host_task_size);
-
-	if (!skas_needs_stub)
-		*task_size_out = host_task_size;
-	else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
-
-	return host_task_size;
-}
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 2c6d090a2e8..902d7413895 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -71,7 +71,7 @@ static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
 	return(-ENOMEM);
 }
 
-int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
+int init_new_context(struct task_struct *task, struct mm_struct *mm)
 {
  	struct mmu_context_skas *from_mm = NULL;
 	struct mmu_context_skas *to_mm = &mm->context.skas;
@@ -137,7 +137,7 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
 	return ret;
 }
 
-void destroy_context_skas(struct mm_struct *mm)
+void destroy_context(struct mm_struct *mm)
 {
 	struct mmu_context_skas *mmu = &mm->context.skas;
 
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
index 48051a98525..dabae62d52b 100644
--- a/arch/um/kernel/skas/process.c
+++ b/arch/um/kernel/skas/process.c
@@ -18,129 +18,22 @@
 #include "os.h"
 #include "tlb.h"
 #include "kern.h"
-#include "mode.h"
 #include "registers.h"
 
-void switch_to_skas(void *prev, void *next)
-{
-	struct task_struct *from, *to;
-
-	from = prev;
-	to = next;
-
-	/* XXX need to check runqueues[cpu].idle */
-	if(current->pid == 0)
-		switch_timers(0);
-
-	switch_threads(&from->thread.mode.skas.switch_buf,
-		       &to->thread.mode.skas.switch_buf);
-
-	arch_switch_to_skas(current->thread.prev_sched, current);
-
-	if(current->pid == 0)
-		switch_timers(1);
-}
-
 extern void schedule_tail(struct task_struct *prev);
 
-/* This is called magically, by its address being stuffed in a jmp_buf
- * and being longjmp-d to.
- */
-void new_thread_handler(void)
-{
-	int (*fn)(void *), n;
-	void *arg;
-
-	if(current->thread.prev_sched != NULL)
-		schedule_tail(current->thread.prev_sched);
-	current->thread.prev_sched = NULL;
-
-	fn = current->thread.request.u.thread.proc;
-	arg = current->thread.request.u.thread.arg;
-
-	/* The return value is 1 if the kernel thread execs a process,
-	 * 0 if it just exits
-	 */
-	n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
-	if(n == 1){
-		/* Handle any immediate reschedules or signals */
-		interrupt_end();
-		userspace(&current->thread.regs.regs);
-	}
-	else do_exit(0);
-}
-
-void release_thread_skas(struct task_struct *task)
-{
-}
-
-/* Called magically, see new_thread_handler above */
-void fork_handler(void)
-{
-	force_flush_all();
-	if(current->thread.prev_sched == NULL)
-		panic("blech");
-
-	schedule_tail(current->thread.prev_sched);
-
-	/* XXX: if interrupt_end() calls schedule, this call to
-	 * arch_switch_to_skas isn't needed. We could want to apply this to
-	 * improve performance. -bb */
-	arch_switch_to_skas(current->thread.prev_sched, current);
-
-	current->thread.prev_sched = NULL;
-
-/* Handle any immediate reschedules or signals */
-	interrupt_end();
-
-	userspace(&current->thread.regs.regs);
-}
-
-int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
-		     unsigned long stack_top, struct task_struct * p,
-		     struct pt_regs *regs)
-{
-	void (*handler)(void);
-
-	if(current->thread.forking){
-	  	memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
-		       sizeof(p->thread.regs.regs.skas));
-		REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
-		if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
-
-		handler = fork_handler;
-
-		arch_copy_thread(&current->thread.arch, &p->thread.arch);
-	}
-	else {
-		init_thread_registers(&p->thread.regs.regs);
-		p->thread.request.u.thread = current->thread.request.u.thread;
-		handler = new_thread_handler;
-	}
-
-	new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
-		   handler);
-	return(0);
-}
-
 int new_mm(unsigned long stack)
 {
 	int fd;
 
 	fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
 	if(fd < 0)
-		return(fd);
+		return fd;
 
 	if(skas_needs_stub)
 		map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
 
-	return(fd);
-}
-
-void init_idle_skas(void)
-{
-	cpu_tasks[current_thread->cpu].pid = os_getpid();
-	default_idle();
+	return fd;
 }
 
 extern void start_kernel(void);
@@ -158,14 +51,14 @@ static int __init start_kernel_proc(void *unused)
 	cpu_online_map = cpumask_of_cpu(0);
 #endif
 	start_kernel();
-	return(0);
+	return 0;
 }
 
 extern int userspace_pid[];
 
 extern char cpu0_irqstack[];
 
-int __init start_uml_skas(void)
+int __init start_uml(void)
 {
 	stack_protections((unsigned long) &cpu0_irqstack);
 	set_sigstack(cpu0_irqstack, THREAD_SIZE);
@@ -176,49 +69,14 @@ int __init start_uml_skas(void)
 
 	init_task.thread.request.u.thread.proc = start_kernel_proc;
 	init_task.thread.request.u.thread.arg = NULL;
-	return(start_idle_thread(task_stack_page(&init_task),
-				 &init_task.thread.mode.skas.switch_buf));
-}
-
-int external_pid_skas(struct task_struct *task)
-{
-	/* FIXME: Need to look up userspace_pid by cpu */
-	return(userspace_pid[0]);
-}
-
-int thread_pid_skas(struct task_struct *task)
-{
-	/* FIXME: Need to look up userspace_pid by cpu */
-	return(userspace_pid[0]);
-}
-
-void kill_off_processes_skas(void)
-{
-	if(proc_mm)
-		/*
-		 * FIXME: need to loop over userspace_pids in
-		 * kill_off_processes_skas
-		 */
-		os_kill_ptraced_process(userspace_pid[0], 1);
-	else {
-		struct task_struct *p;
-		int pid, me;
-
-		me = os_getpid();
-		for_each_process(p){
-			if(p->mm == NULL)
-				continue;
-
-			pid = p->mm->context.skas.id.u.pid;
-			os_kill_ptraced_process(pid, 1);
-		}
-	}
+	return start_idle_thread(task_stack_page(&init_task),
+				 &init_task.thread.switch_buf);
 }
 
 unsigned long current_stub_stack(void)
 {
 	if(current->mm == NULL)
-		return(0);
+		return 0;
 
-	return(current->mm->context.skas.id.stack);
+	return current->mm->context.skas.id.stack;
 }
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index 0ae4eea21be..e183da633c8 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c
@@ -13,7 +13,7 @@
 #include "kern_util.h"
 #include "syscall.h"
 
-void handle_syscall(union uml_pt_regs *r)
+void handle_syscall(struct uml_pt_regs *r)
 {
 	struct pt_regs *regs = container_of(r, struct pt_regs, regs);
 	long result;
@@ -37,7 +37,7 @@ void handle_syscall(union uml_pt_regs *r)
 		result = -ENOSYS;
 	else result = EXECUTE_SYSCALL(syscall, regs);
 
-	REGS_SET_SYSCALL_RETURN(r->skas.regs, result);
+	REGS_SET_SYSCALL_RETURN(r->regs, result);
 
 	syscall_trace(r, 1);
 }
diff --git a/arch/um/kernel/skas/tlb.c b/arch/um/kernel/skas/tlb.c
deleted file mode 100644
index c0f0693743b..00000000000
--- a/arch/um/kernel/skas/tlb.c
+++ /dev/null
@@ -1,164 +0,0 @@
-/* 
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
- * Copyright 2003 PathScale, Inc.
- * Licensed under the GPL
- */
-
-#include "linux/stddef.h"
-#include "linux/sched.h"
-#include "linux/mm.h"
-#include "asm/page.h"
-#include "asm/pgtable.h"
-#include "asm/mmu.h"
-#include "mem_user.h"
-#include "mem.h"
-#include "skas.h"
-#include "os.h"
-#include "tlb.h"
-
-static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
-		  int finished, void **flush)
-{
-	struct host_vm_op *op;
-        int i, ret = 0;
-
-        for(i = 0; i <= last && !ret; i++){
-		op = &ops[i];
-		switch(op->type){
-		case MMAP:
-			ret = map(&mmu->skas.id, op->u.mmap.addr,
-				  op->u.mmap.len, op->u.mmap.prot,
-				  op->u.mmap.fd, op->u.mmap.offset, finished,
-				  flush);
-			break;
-		case MUNMAP:
-			ret = unmap(&mmu->skas.id, op->u.munmap.addr,
-				    op->u.munmap.len, finished, flush);
-			break;
-		case MPROTECT:
-			ret = protect(&mmu->skas.id, op->u.mprotect.addr,
-				      op->u.mprotect.len, op->u.mprotect.prot,
-				      finished, flush);
-			break;
-		default:
-			printk("Unknown op type %d in do_ops\n", op->type);
-			break;
-		}
-	}
-
-	return ret;
-}
-
-extern int proc_mm;
-
-static void fix_range(struct mm_struct *mm, unsigned long start_addr,
-		      unsigned long end_addr, int force)
-{
-        if(!proc_mm && (end_addr > CONFIG_STUB_START))
-                end_addr = CONFIG_STUB_START;
-
-        fix_range_common(mm, start_addr, end_addr, force, do_ops);
-}
-
-void __flush_tlb_one_skas(unsigned long addr)
-{
-        flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
-}
-
-void flush_tlb_range_skas(struct vm_area_struct *vma, unsigned long start, 
-		     unsigned long end)
-{
-        if(vma->vm_mm == NULL)
-                flush_tlb_kernel_range_common(start, end);
-        else fix_range(vma->vm_mm, start, end, 0);
-}
-
-void flush_tlb_mm_skas(struct mm_struct *mm)
-{
-	unsigned long end;
-
-	/* Don't bother flushing if this address space is about to be
-         * destroyed.
-         */
-        if(atomic_read(&mm->mm_users) == 0)
-                return;
-
-	end = proc_mm ? task_size : CONFIG_STUB_START;
-        fix_range(mm, 0, end, 0);
-}
-
-void force_flush_all_skas(void)
-{
-	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma = mm->mmap;
-
-	while(vma != NULL) {
-		fix_range(mm, vma->vm_start, vma->vm_end, 1);
-		vma = vma->vm_next;
-	}
-}
-
-void flush_tlb_page_skas(struct vm_area_struct *vma, unsigned long address)
-{
-	pgd_t *pgd;
-	pud_t *pud;
-	pmd_t *pmd;
-	pte_t *pte;
-	struct mm_struct *mm = vma->vm_mm;
-	void *flush = NULL;
-	int r, w, x, prot, err = 0;
-	struct mm_id *mm_id;
-
-	pgd = pgd_offset(mm, address);
-	if(!pgd_present(*pgd))
-		goto kill;
-
-	pud = pud_offset(pgd, address);
-	if(!pud_present(*pud))
-		goto kill;
-
-	pmd = pmd_offset(pud, address);
-	if(!pmd_present(*pmd))
-		goto kill;
-
-	pte = pte_offset_kernel(pmd, address);
-
-	r = pte_read(*pte);
-	w = pte_write(*pte);
-	x = pte_exec(*pte);
-	if (!pte_young(*pte)) {
-		r = 0;
-		w = 0;
-	} else if (!pte_dirty(*pte)) {
-		w = 0;
-	}
-
-	mm_id = &mm->context.skas.id;
-	prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
-		(x ? UM_PROT_EXEC : 0));
-	if(pte_newpage(*pte)){
-		if(pte_present(*pte)){
-			unsigned long long offset;
-			int fd;
-
-			fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
-			err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
-				  1, &flush);
-		}
-		else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
-	}
-	else if(pte_newprot(*pte))
-		err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
-
-	if(err)
-		goto kill;
-
-	*pte = pte_mkuptodate(*pte);
-
-	return;
-
-kill:
-	printk("Failed to flush page for address 0x%lx\n", address);
-	force_sig(SIGKILL, current);
-}
-
diff --git a/arch/um/kernel/syscall.c b/arch/um/kernel/syscall.c
index 138bcb43b99..ebb29f5259a 100644
--- a/arch/um/kernel/syscall.c
+++ b/arch/um/kernel/syscall.c
@@ -20,7 +20,6 @@
 #include "asm/uaccess.h"
 #include "kern_util.h"
 #include "sysdep/syscalls.h"
-#include "mode_kern.h"
 
 /*  Unlocked, I don't care if this is a bit off */
 int nsyscalls = 0;
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 3571703a7cb..90e24e2dbea 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -18,7 +18,6 @@
 #include "asm/param.h"
 #include "asm/current.h"
 #include "kern_util.h"
-#include "mode.h"
 #include "os.h"
 
 int hz(void)
@@ -39,7 +38,7 @@ static unsigned long long prev_nsecs[NR_CPUS];
 static long long delta[NR_CPUS];		/* Deviation per interval */
 #endif
 
-void timer_irq(union uml_pt_regs *regs)
+void timer_irq(struct uml_pt_regs *regs)
 {
 	unsigned long long ticks = 0;
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
@@ -175,13 +174,13 @@ int do_settimeofday(struct timespec *tv)
 	return 0;
 }
 
-void timer_handler(int sig, union uml_pt_regs *regs)
+void timer_handler(int sig, struct uml_pt_regs *regs)
 {
 	if(current_thread->cpu == 0)
 		timer_irq(regs);
 	local_irq_disable();
 	irq_enter();
-	update_process_times((regs)->skas.is_user);
+	update_process_times(regs->is_user);
 	irq_exit();
 	local_irq_enable();
 }
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 312e8ba30cd..12b8c637527 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -8,12 +8,12 @@
 #include "asm/pgalloc.h"
 #include "asm/pgtable.h"
 #include "asm/tlbflush.h"
-#include "mode_kern.h"
 #include "as-layout.h"
 #include "tlb.h"
 #include "mem.h"
 #include "mem_user.h"
 #include "os.h"
+#include "skas.h"
 
 static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
 		    unsigned int prot, struct host_vm_op *ops, int *index,
@@ -341,6 +341,71 @@ int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
 	return(updated);
 }
 
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	struct mm_struct *mm = vma->vm_mm;
+	void *flush = NULL;
+	int r, w, x, prot, err = 0;
+	struct mm_id *mm_id;
+
+	address &= PAGE_MASK;
+	pgd = pgd_offset(mm, address);
+	if(!pgd_present(*pgd))
+		goto kill;
+
+	pud = pud_offset(pgd, address);
+	if(!pud_present(*pud))
+		goto kill;
+
+	pmd = pmd_offset(pud, address);
+	if(!pmd_present(*pmd))
+		goto kill;
+
+	pte = pte_offset_kernel(pmd, address);
+
+	r = pte_read(*pte);
+	w = pte_write(*pte);
+	x = pte_exec(*pte);
+	if (!pte_young(*pte)) {
+		r = 0;
+		w = 0;
+	} else if (!pte_dirty(*pte)) {
+		w = 0;
+	}
+
+	mm_id = &mm->context.skas.id;
+	prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
+		(x ? UM_PROT_EXEC : 0));
+	if(pte_newpage(*pte)){
+		if(pte_present(*pte)){
+			unsigned long long offset;
+			int fd;
+
+			fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
+			err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
+				  1, &flush);
+		}
+		else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
+	}
+	else if(pte_newprot(*pte))
+		err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
+
+	if(err)
+		goto kill;
+
+	*pte = pte_mkuptodate(*pte);
+
+	return;
+
+kill:
+	printk("Failed to flush page for address 0x%lx\n", address);
+	force_sig(SIGKILL, current);
+}
+
 pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
 {
 	return(pgd_offset(mm, address));
@@ -387,21 +452,80 @@ void flush_tlb_kernel_vm(void)
 
 void __flush_tlb_one(unsigned long addr)
 {
-	__flush_tlb_one_skas(addr);
+        flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
+}
+
+static int do_ops(union mm_context *mmu, struct host_vm_op *ops, int last,
+		  int finished, void **flush)
+{
+	struct host_vm_op *op;
+        int i, ret = 0;
+
+        for(i = 0; i <= last && !ret; i++){
+		op = &ops[i];
+		switch(op->type){
+		case MMAP:
+			ret = map(&mmu->skas.id, op->u.mmap.addr,
+				  op->u.mmap.len, op->u.mmap.prot,
+				  op->u.mmap.fd, op->u.mmap.offset, finished,
+				  flush);
+			break;
+		case MUNMAP:
+			ret = unmap(&mmu->skas.id, op->u.munmap.addr,
+				    op->u.munmap.len, finished, flush);
+			break;
+		case MPROTECT:
+			ret = protect(&mmu->skas.id, op->u.mprotect.addr,
+				      op->u.mprotect.len, op->u.mprotect.prot,
+				      finished, flush);
+			break;
+		default:
+			printk("Unknown op type %d in do_ops\n", op->type);
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static void fix_range(struct mm_struct *mm, unsigned long start_addr,
+		      unsigned long end_addr, int force)
+{
+        if(!proc_mm && (end_addr > CONFIG_STUB_START))
+                end_addr = CONFIG_STUB_START;
+
+        fix_range_common(mm, start_addr, end_addr, force, do_ops);
 }
 
 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 		     unsigned long end)
 {
-	flush_tlb_range_skas(vma, start, end);
+        if(vma->vm_mm == NULL)
+                flush_tlb_kernel_range_common(start, end);
+        else fix_range(vma->vm_mm, start, end, 0);
 }
 
 void flush_tlb_mm(struct mm_struct *mm)
 {
-	flush_tlb_mm_skas(mm);
+	unsigned long end;
+
+	/* Don't bother flushing if this address space is about to be
+         * destroyed.
+         */
+        if(atomic_read(&mm->mm_users) == 0)
+                return;
+
+	end = proc_mm ? task_size : CONFIG_STUB_START;
+        fix_range(mm, 0, end, 0);
 }
 
 void force_flush_all(void)
 {
-	force_flush_all_skas();
+	struct mm_struct *mm = current->mm;
+	struct vm_area_struct *vma = mm->mmap;
+
+	while(vma != NULL) {
+		fix_range(mm, vma->vm_start, vma->vm_end, 1);
+		vma = vma->vm_next;
+	}
 }
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 4b472ca5348..eac63fb6183 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -128,7 +128,7 @@ static void bad_segv(struct faultinfo fi, unsigned long ip)
 	force_sig_info(SIGSEGV, &si, current);
 }
 
-static void segv_handler(int sig, union uml_pt_regs *regs)
+static void segv_handler(int sig, struct uml_pt_regs *regs)
 {
 	struct faultinfo * fi = UPT_FAULTINFO(regs);
 
@@ -146,7 +146,7 @@ static void segv_handler(int sig, union uml_pt_regs *regs)
  * give us bad data!
  */
 unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
-		   union uml_pt_regs *regs)
+		   struct uml_pt_regs *regs)
 {
 	struct siginfo si;
 	void *catcher;
@@ -214,7 +214,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 	return 0;
 }
 
-void relay_signal(int sig, union uml_pt_regs *regs)
+void relay_signal(int sig, struct uml_pt_regs *regs)
 {
 	if (arch_handle_signal(sig, regs))
 		return;
@@ -230,14 +230,14 @@ void relay_signal(int sig, union uml_pt_regs *regs)
 	force_sig(sig, current);
 }
 
-static void bus_handler(int sig, union uml_pt_regs *regs)
+static void bus_handler(int sig, struct uml_pt_regs *regs)
 {
 	if (current->thread.fault_catcher != NULL)
 		do_longjmp(current->thread.fault_catcher, 1);
 	else relay_signal(sig, regs);
 }
 
-static void winch(int sig, union uml_pt_regs *regs)
+static void winch(int sig, struct uml_pt_regs *regs)
 {
 	do_IRQ(WINCH_IRQ, regs);
 }
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 9f3a207eb81..5f3e13c365e 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -35,8 +35,6 @@
 #include "initrd.h"
 #include "init.h"
 #include "os.h"
-#include "mode_kern.h"
-#include "mode.h"
 #include "skas.h"
 
 #define DEFAULT_COMMAND_LINE "root=98:0"
@@ -67,7 +65,8 @@ struct cpuinfo_um boot_cpu_data = {
 
 unsigned long thread_saved_pc(struct task_struct *task)
 {
-	return os_process_pc(thread_pid_skas(task));
+	/* FIXME: Need to look up userspace_pid by cpu */
+	return os_process_pc(userspace_pid[0]);
 }
 
 /* Changed in setup_arch, which is called in early boot */
@@ -253,6 +252,19 @@ EXPORT_SYMBOL(end_iomem);
 
 extern char __binary_start;
 
+static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
+{
+	/* Round up to the nearest 4M */
+	unsigned long host_task_size = ROUND_4M((unsigned long)
+						&host_task_size);
+
+	if (!skas_needs_stub)
+		*task_size_out = host_task_size;
+	else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
+
+	return host_task_size;
+}
+
 int __init linux_main(int argc, char **argv)
 {
 	unsigned long avail, diff;
@@ -289,7 +301,7 @@ int __init linux_main(int argc, char **argv)
 	os_fill_handlinfo(handlinfo_kern);
 
 	brk_start = (unsigned long) sbrk(0);
-	before_mem_skas(brk_start);
+
 	/* Increase physical memory size for exec-shield users
 	so they actually get what they asked for. This should
 	add zero for non-exec shield users */
@@ -354,7 +366,7 @@ int __init linux_main(int argc, char **argv)
 	stack_protections((unsigned long) &init_thread_info);
 	os_flush_stdout();
 
-	return start_uml_skas();
+	return start_uml();
 }
 
 extern int uml_exitcode;