d6dd61c831
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>
91 lines
2.3 KiB
C
91 lines
2.3 KiB
C
/*
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* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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*/
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#ifndef __UM_MMU_CONTEXT_H
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#define __UM_MMU_CONTEXT_H
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#include <asm-generic/mm_hooks.h>
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#include "linux/sched.h"
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#include "choose-mode.h"
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#include "um_mmu.h"
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#define get_mmu_context(task) do ; while(0)
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#define activate_context(tsk) do ; while(0)
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#define deactivate_mm(tsk,mm) do { } while (0)
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extern void force_flush_all(void);
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static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
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{
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/*
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* This is called by fs/exec.c and fs/aio.c. In the first case, for an
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* exec, we don't need to do anything as we're called from userspace
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* and thus going to use a new host PID. In the second, we're called
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* from a kernel thread, and thus need to go doing the mmap's on the
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* host. Since they're very expensive, we want to avoid that as far as
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* possible.
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*/
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if (old != new && (current->flags & PF_BORROWED_MM))
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CHOOSE_MODE(force_flush_all(),
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switch_mm_skas(&new->context.skas.id));
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}
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static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
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struct task_struct *tsk)
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{
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unsigned cpu = smp_processor_id();
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if(prev != next){
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cpu_clear(cpu, prev->cpu_vm_mask);
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cpu_set(cpu, next->cpu_vm_mask);
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if(next != &init_mm)
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CHOOSE_MODE((void) 0,
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switch_mm_skas(&next->context.skas.id));
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}
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}
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static inline void enter_lazy_tlb(struct mm_struct *mm,
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struct task_struct *tsk)
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{
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}
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extern int init_new_context_skas(struct task_struct *task,
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struct mm_struct *mm);
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static inline int init_new_context_tt(struct task_struct *task,
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struct mm_struct *mm)
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{
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return(0);
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}
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static inline int init_new_context(struct task_struct *task,
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struct mm_struct *mm)
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{
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return(CHOOSE_MODE_PROC(init_new_context_tt, init_new_context_skas,
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task, mm));
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}
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extern void destroy_context_skas(struct mm_struct *mm);
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static inline void destroy_context(struct mm_struct *mm)
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{
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CHOOSE_MODE((void) 0, destroy_context_skas(mm));
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}
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#endif
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/*
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* Overrides for Emacs so that we follow Linus's tabbing style.
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* Emacs will notice this stuff at the end of the file and automatically
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* adjust the settings for this buffer only. This must remain at the end
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* of the file.
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* ---------------------------------------------------------------------------
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* Local variables:
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* c-file-style: "linux"
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* End:
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*/
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