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	 45e576b1c3
			
		
	
	
		45e576b1c3
		
	
	
	
	
		
			
			Use the existing arch_alloc_page/arch_free_page callbacks to do the guest page state transitions between stable and unused. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
		
			
				
	
	
		
			80 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			80 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * arch/s390/mm/page-states.c
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|  *
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|  * Copyright IBM Corp. 2008
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|  *
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|  * Guest page hinting for unused pages.
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|  *
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|  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/errno.h>
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| #include <linux/types.h>
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| #include <linux/mm.h>
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| #include <linux/init.h>
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| 
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| #define ESSA_SET_STABLE		1
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| #define ESSA_SET_UNUSED		2
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| 
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| static int cmma_flag;
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| 
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| static int __init cmma(char *str)
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| {
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| 	char *parm;
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| 	parm = strstrip(str);
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| 	if (strcmp(parm, "yes") == 0 || strcmp(parm, "on") == 0) {
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| 		cmma_flag = 1;
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| 		return 1;
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| 	}
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| 	cmma_flag = 0;
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| 	if (strcmp(parm, "no") == 0 || strcmp(parm, "off") == 0)
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| 		return 1;
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| 	return 0;
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| }
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| 
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| __setup("cmma=", cmma);
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| 
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| void __init cmma_init(void)
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| {
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| 	register unsigned long tmp asm("0") = 0;
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| 	register int rc asm("1") = -EOPNOTSUPP;
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| 
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| 	if (!cmma_flag)
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| 		return;
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| 	asm volatile(
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| 		"       .insn rrf,0xb9ab0000,%1,%1,0,0\n"
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| 		"0:     la      %0,0\n"
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| 		"1:\n"
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| 		EX_TABLE(0b,1b)
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| 		: "+&d" (rc), "+&d" (tmp));
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| 	if (rc)
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| 		cmma_flag = 0;
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| }
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| 
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| void arch_free_page(struct page *page, int order)
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| {
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| 	int i, rc;
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| 
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| 	if (!cmma_flag)
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| 		return;
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| 	for (i = 0; i < (1 << order); i++)
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| 		asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
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| 			     : "=&d" (rc)
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| 			     : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT),
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| 			       "i" (ESSA_SET_UNUSED));
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| }
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| 
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| void arch_alloc_page(struct page *page, int order)
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| {
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| 	int i, rc;
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| 
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| 	if (!cmma_flag)
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| 		return;
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| 	for (i = 0; i < (1 << order); i++)
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| 		asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0"
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| 			     : "=&d" (rc)
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| 			     : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT),
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| 			       "i" (ESSA_SET_STABLE));
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| }
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