 a53efe5ff8
			
		
	
	
	a53efe5ff8
	
	
	
		
			
			The finish_arch_post_lock_switch is called at the end of the task switch after all locks have been released. In concept it is paired with the switch_mm function, but the current code only does the call in finish_task_switch. Add the call to idle_task_exit and use_mm. One use case for the additional calls is s390 which will use finish_arch_post_lock_switch to wait for the completion of TLB flush operations. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
		
			
				
	
	
		
			62 lines
		
	
	
	
		
			1.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			62 lines
		
	
	
	
		
			1.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (C) 2009 Red Hat, Inc.
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|  *
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|  * See ../COPYING for licensing terms.
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|  */
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| 
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| #include <linux/mm.h>
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| #include <linux/mmu_context.h>
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| #include <linux/export.h>
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| #include <linux/sched.h>
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| 
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| #include <asm/mmu_context.h>
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| 
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| /*
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|  * use_mm
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|  *	Makes the calling kernel thread take on the specified
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|  *	mm context.
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|  *	(Note: this routine is intended to be called only
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|  *	from a kernel thread context)
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|  */
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| void use_mm(struct mm_struct *mm)
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| {
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| 	struct mm_struct *active_mm;
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| 	struct task_struct *tsk = current;
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| 
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| 	task_lock(tsk);
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| 	active_mm = tsk->active_mm;
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| 	if (active_mm != mm) {
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| 		atomic_inc(&mm->mm_count);
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| 		tsk->active_mm = mm;
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| 	}
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| 	tsk->mm = mm;
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| 	switch_mm(active_mm, mm, tsk);
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| 	task_unlock(tsk);
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| #ifdef finish_arch_post_lock_switch
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| 	finish_arch_post_lock_switch();
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| #endif
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| 
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| 	if (active_mm != mm)
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| 		mmdrop(active_mm);
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| }
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| EXPORT_SYMBOL_GPL(use_mm);
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| 
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| /*
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|  * unuse_mm
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|  *	Reverses the effect of use_mm, i.e. releases the
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|  *	specified mm context which was earlier taken on
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|  *	by the calling kernel thread
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|  *	(Note: this routine is intended to be called only
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|  *	from a kernel thread context)
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|  */
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| void unuse_mm(struct mm_struct *mm)
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| {
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| 	struct task_struct *tsk = current;
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| 
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| 	task_lock(tsk);
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| 	sync_mm_rss(mm);
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| 	tsk->mm = NULL;
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| 	/* active_mm is still 'mm' */
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| 	enter_lazy_tlb(mm, tsk);
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| 	task_unlock(tsk);
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| }
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| EXPORT_SYMBOL_GPL(unuse_mm);
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