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Commit c0b96cf6 authored by Paul Mundt's avatar Paul Mundt
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sh: Provide _PAGE_SPECIAL for 32-bit. 



Allocate one of the unused PTE bits for _PAGE_SPECIAL directly. This is
prep work for fast gup and the zero page revival.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent fc6cca39

arch/sh/include/asm/pgtable_32.h

+10 −4
Original line number Diff line number Diff line
@@ -20,7 +20,7 @@ 
 * - Bit 9 is reserved by everyone and used by _PAGE_PROTNONE.

 *

 * - Bits 10 and 11 are low bits of the PPN that are reserved on >= 4K pages.

 *   Bit 10 is used for _PAGE_ACCESSED, bit 11 remains unused.

 *   Bit 10 is used for _PAGE_ACCESSED, and bit 11 is used for _PAGE_SPECIAL.

 *

 * - On 29 bit platforms, bits 31 to 29 are used for the space attributes

 *   and timing control which (together with bit 0) are moved into the
@@ -52,6 +52,7 @@ 
#define _PAGE_PROTNONE	0x200		/* software: if not present  */

#define _PAGE_ACCESSED	0x400		/* software: page referenced */

#define _PAGE_FILE	_PAGE_WT	/* software: pagecache or swap? */

#define _PAGE_SPECIAL	0x800		/* software: special page */



#define _PAGE_SZ_MASK	(_PAGE_SZ0 | _PAGE_SZ1)

#define _PAGE_PR_MASK	(_PAGE_RW | _PAGE_USER)
@@ -148,8 +149,12 @@ 
# define _PAGE_SZHUGE	(_PAGE_FLAGS_HARD)

#endif



/*

 * Mask of bits that are to be preserved accross pgprot changes.

 */

#define _PAGE_CHG_MASK \

	(PTE_MASK | _PAGE_ACCESSED | _PAGE_CACHABLE | _PAGE_DIRTY)

	(PTE_MASK | _PAGE_ACCESSED | _PAGE_CACHABLE | \

	 _PAGE_DIRTY | _PAGE_SPECIAL)



#ifndef __ASSEMBLY__
@@ -328,7 +333,7 @@ static inline void set_pte(pte_t *ptep, pte_t pte) 
#define pte_dirty(pte)		((pte).pte_low & _PAGE_DIRTY)

#define pte_young(pte)		((pte).pte_low & _PAGE_ACCESSED)

#define pte_file(pte)		((pte).pte_low & _PAGE_FILE)

#define pte_special(pte)	(0)

#define pte_special(pte)	((pte).pte_low & _PAGE_SPECIAL)



#ifdef CONFIG_X2TLB

#define pte_write(pte)		((pte).pte_high & _PAGE_EXT_USER_WRITE)
@@ -358,8 +363,9 @@ PTE_BIT_FUNC(low, mkclean, &= ~_PAGE_DIRTY); 
PTE_BIT_FUNC(low, mkdirty, |= _PAGE_DIRTY);

PTE_BIT_FUNC(low, mkold, &= ~_PAGE_ACCESSED);

PTE_BIT_FUNC(low, mkyoung, |= _PAGE_ACCESSED);

PTE_BIT_FUNC(low, mkspecial, |= _PAGE_SPECIAL);



static inline pte_t pte_mkspecial(pte_t pte) { return pte; }

#define __HAVE_ARCH_PTE_SPECIAL



/*

 * Macro and implementation to make a page protection as uncachable.