One of the changes necessary for shared page tables is to standardize the pxx_page macros. pte_page and pmd_page have always returned the struct page associated with their entry, while pte_page_kernel and pmd_page_kernel have returned the kernel virtual address. pud_page and pgd_page, on the other hand, return the kernel virtual address. Shared page tables needs pud_page and pgd_page to return the actual page structures. There are very few actual users of these functions, so it is simple to standardize their usage. Since this is basic cleanup, I am submitting these changes as a standalone patch. Per Hugh Dickins' comments about it, I am also changing the pxx_page_kernel macros to pxx_page_vaddr to clarify their meaning. Signed-off-by: Dave McCracken <dmccr@us.ibm.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
		
			
				
	
	
		
			61 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			61 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _PGTABLE_NOPUD_H
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#define _PGTABLE_NOPUD_H
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#ifndef __ASSEMBLY__
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#define __PAGETABLE_PUD_FOLDED
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/*
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 * Having the pud type consist of a pgd gets the size right, and allows
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 * us to conceptually access the pgd entry that this pud is folded into
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 * without casting.
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 */
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typedef struct { pgd_t pgd; } pud_t;
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#define PUD_SHIFT	PGDIR_SHIFT
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#define PTRS_PER_PUD	1
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#define PUD_SIZE  	(1UL << PUD_SHIFT)
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#define PUD_MASK  	(~(PUD_SIZE-1))
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/*
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 * The "pgd_xxx()" functions here are trivial for a folded two-level
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 * setup: the pud is never bad, and a pud always exists (as it's folded
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 * into the pgd entry)
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 */
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static inline int pgd_none(pgd_t pgd)		{ return 0; }
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static inline int pgd_bad(pgd_t pgd)		{ return 0; }
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static inline int pgd_present(pgd_t pgd)	{ return 1; }
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static inline void pgd_clear(pgd_t *pgd)	{ }
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#define pud_ERROR(pud)				(pgd_ERROR((pud).pgd))
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#define pgd_populate(mm, pgd, pud)		do { } while (0)
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/*
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 * (puds are folded into pgds so this doesn't get actually called,
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 * but the define is needed for a generic inline function.)
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 */
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#define set_pgd(pgdptr, pgdval)			set_pud((pud_t *)(pgdptr), (pud_t) { pgdval })
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static inline pud_t * pud_offset(pgd_t * pgd, unsigned long address)
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{
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	return (pud_t *)pgd;
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}
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#define pud_val(x)				(pgd_val((x).pgd))
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#define __pud(x)				((pud_t) { __pgd(x) } )
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#define pgd_page(pgd)				(pud_page((pud_t){ pgd }))
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#define pgd_page_vaddr(pgd)			(pud_page_vaddr((pud_t){ pgd }))
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/*
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 * allocating and freeing a pud is trivial: the 1-entry pud is
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 * inside the pgd, so has no extra memory associated with it.
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 */
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#define pud_alloc_one(mm, address)		NULL
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#define pud_free(x)				do { } while (0)
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#define __pud_free_tlb(tlb, x)			do { } while (0)
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#undef  pud_addr_end
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#define pud_addr_end(addr, end)			(end)
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#endif /* __ASSEMBLY__ */
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#endif /* _PGTABLE_NOPUD_H */
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