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>
		
			
				
	
	
		
			65 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			65 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _PGTABLE_NOPMD_H
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#define _PGTABLE_NOPMD_H
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#ifndef __ASSEMBLY__
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#include <asm-generic/pgtable-nopud.h>
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#define __PAGETABLE_PMD_FOLDED
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/*
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 * Having the pmd type consist of a pud gets the size right, and allows
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 * us to conceptually access the pud entry that this pmd is folded into
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 * without casting.
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 */
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typedef struct { pud_t pud; } pmd_t;
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#define PMD_SHIFT	PUD_SHIFT
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#define PTRS_PER_PMD	1
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#define PMD_SIZE  	(1UL << PMD_SHIFT)
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#define PMD_MASK  	(~(PMD_SIZE-1))
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/*
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 * The "pud_xxx()" functions here are trivial for a folded two-level
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 * setup: the pmd is never bad, and a pmd always exists (as it's folded
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 * into the pud entry)
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 */
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static inline int pud_none(pud_t pud)		{ return 0; }
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static inline int pud_bad(pud_t pud)		{ return 0; }
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static inline int pud_present(pud_t pud)	{ return 1; }
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static inline void pud_clear(pud_t *pud)	{ }
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#define pmd_ERROR(pmd)				(pud_ERROR((pmd).pud))
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#define pud_populate(mm, pmd, pte)		do { } while (0)
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/*
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 * (pmds are folded into puds 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_pud(pudptr, pudval)			set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
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static inline pmd_t * pmd_offset(pud_t * pud, unsigned long address)
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{
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	return (pmd_t *)pud;
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}
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#define pmd_val(x)				(pud_val((x).pud))
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#define __pmd(x)				((pmd_t) { __pud(x) } )
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#define pud_page(pud)				(pmd_page((pmd_t){ pud }))
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#define pud_page_vaddr(pud)			(pmd_page_vaddr((pmd_t){ pud }))
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/*
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 * allocating and freeing a pmd is trivial: the 1-entry pmd is
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 * inside the pud, so has no extra memory associated with it.
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 */
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#define pmd_alloc_one(mm, address)		NULL
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#define pmd_free(x)				do { } while (0)
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#define __pmd_free_tlb(tlb, x)			do { } while (0)
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#undef  pmd_addr_end
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#define pmd_addr_end(addr, end)			(end)
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#endif /* __ASSEMBLY__ */
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#endif /* _PGTABLE_NOPMD_H */
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