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linux/include/asm-um/mmu_context.h
Jeremy Fitzhardinge d6dd61c831 [PATCH] x86: PARAVIRT: add hooks to intercept mm creation and destruction
Add hooks to allow a paravirt implementation to track the lifetime of
an mm.  Paravirtualization requires three hooks, but only two are
needed in common code.  They are:

arch_dup_mmap, which is called when a new mmap is created at fork

arch_exit_mmap, which is called when the last process reference to an
  mm is dropped, which typically happens on exit and exec.

The third hook is activate_mm, which is called from the arch-specific
activate_mm() macro/function, and so doesn't need stub versions for
other architectures.  It's called when an mm is first used.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: linux-arch@vger.kernel.org
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
2007-05-02 19:27:14 +02:00

91 lines
2.3 KiB
C

/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#ifndef __UM_MMU_CONTEXT_H
#define __UM_MMU_CONTEXT_H
#include <asm-generic/mm_hooks.h>
#include "linux/sched.h"
#include "choose-mode.h"
#include "um_mmu.h"
#define get_mmu_context(task) do ; while(0)
#define activate_context(tsk) do ; while(0)
#define deactivate_mm(tsk,mm) do { } while (0)
extern void force_flush_all(void);
static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
{
/*
* This is called by fs/exec.c and fs/aio.c. In the first case, for an
* exec, we don't need to do anything as we're called from userspace
* and thus going to use a new host PID. In the second, we're called
* from a kernel thread, and thus need to go doing the mmap's on the
* host. Since they're very expensive, we want to avoid that as far as
* possible.
*/
if (old != new && (current->flags & PF_BORROWED_MM))
CHOOSE_MODE(force_flush_all(),
switch_mm_skas(&new->context.skas.id));
}
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
unsigned cpu = smp_processor_id();
if(prev != next){
cpu_clear(cpu, prev->cpu_vm_mask);
cpu_set(cpu, next->cpu_vm_mask);
if(next != &init_mm)
CHOOSE_MODE((void) 0,
switch_mm_skas(&next->context.skas.id));
}
}
static inline void enter_lazy_tlb(struct mm_struct *mm,
struct task_struct *tsk)
{
}
extern int init_new_context_skas(struct task_struct *task,
struct mm_struct *mm);
static inline int init_new_context_tt(struct task_struct *task,
struct mm_struct *mm)
{
return(0);
}
static inline int init_new_context(struct task_struct *task,
struct mm_struct *mm)
{
return(CHOOSE_MODE_PROC(init_new_context_tt, init_new_context_skas,
task, mm));
}
extern void destroy_context_skas(struct mm_struct *mm);
static inline void destroy_context(struct mm_struct *mm)
{
CHOOSE_MODE((void) 0, destroy_context_skas(mm));
}
#endif
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/