arch/mips/include/asm/pgtable-bits.h - linux/kernel/git/viro/vfs - Git at Google

 /*
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
  * Copyright (C) 1994 - 2002 by Ralf Baechle
  * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
  * Copyright (C) 2002  Maciej W. Rozycki
  */
 #ifndef _ASM_PGTABLE_BITS_H
 #define _ASM_PGTABLE_BITS_H


 /*
  * Note that we shift the lower 32bits of each EntryLo[01] entry
  * 6 bits to the left. That way we can convert the PFN into the
  * physical address by a single 'and' operation and gain 6 additional
  * bits for storing information which isn't present in a normal
  * MIPS page table.
  *
  * Similar to the Alpha port, we need to keep track of the ref
  * and mod bits in software.  We have a software "yeah you can read
  * from this page" bit, and a hardware one which actually lets the
  * process read from the page.	On the same token we have a software
  * writable bit and the real hardware one which actually lets the
  * process write to the page, this keeps a mod bit via the hardware
  * dirty bit.
  *
  * Certain revisions of the R4000 and R5000 have a bug where if a
  * certain sequence occurs in the last 3 instructions of an executable
  * page, and the following page is not mapped, the cpu can do
  * unpredictable things.  The code (when it is written) to deal with
  * this problem will be in the update_mmu_cache() code for the r4k.
  */
 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)

 /*
  * The following bits are directly used by the TLB hardware
  */
 #define _PAGE_R4KBUG		(1 << 0)  /* workaround for r4k bug  */
 #define _PAGE_GLOBAL		(1 << 0)
 #define _PAGE_VALID_SHIFT	1
 #define _PAGE_VALID		(1 << _PAGE_VALID_SHIFT)
 #define _PAGE_SILENT_READ	(1 << 1)  /* synonym		     */
 #define _PAGE_DIRTY_SHIFT	2
 #define _PAGE_DIRTY		(1 << _PAGE_DIRTY_SHIFT)  /* The MIPS dirty bit	     */
 #define _PAGE_SILENT_WRITE	(1 << 2)
 #define _CACHE_SHIFT		3
 #define _CACHE_MASK		(7 << 3)

 /*
  * The following bits are implemented in software
  *
  * _PAGE_FILE semantics: set:pagecache unset:swap
  */
 #define _PAGE_PRESENT_SHIFT	6
 #define _PAGE_PRESENT		(1 << _PAGE_PRESENT_SHIFT)
 #define _PAGE_READ_SHIFT	7
 #define _PAGE_READ		(1 << _PAGE_READ_SHIFT)
 #define _PAGE_WRITE_SHIFT	8
 #define _PAGE_WRITE		(1 << _PAGE_WRITE_SHIFT)
 #define _PAGE_ACCESSED_SHIFT	9
 #define _PAGE_ACCESSED		(1 << _PAGE_ACCESSED_SHIFT)
 #define _PAGE_MODIFIED_SHIFT	10
 #define _PAGE_MODIFIED		(1 << _PAGE_MODIFIED_SHIFT)

 #define _PAGE_FILE		(1 << 10)

 #elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)

 /*
  * The following are implemented by software
  *
  * _PAGE_FILE semantics: set:pagecache unset:swap
  */
 #define _PAGE_PRESENT_SHIFT	0
 #define _PAGE_PRESENT		(1 <<  _PAGE_PRESENT_SHIFT)
 #define _PAGE_READ_SHIFT	1
 #define _PAGE_READ		(1 <<  _PAGE_READ_SHIFT)
 #define _PAGE_WRITE_SHIFT	2
 #define _PAGE_WRITE		(1 <<  _PAGE_WRITE_SHIFT)
 #define _PAGE_ACCESSED_SHIFT	3
 #define _PAGE_ACCESSED		(1 <<  _PAGE_ACCESSED_SHIFT)
 #define _PAGE_MODIFIED_SHIFT	4
 #define _PAGE_MODIFIED		(1 <<  _PAGE_MODIFIED_SHIFT)
 #define _PAGE_FILE_SHIFT	4
 #define _PAGE_FILE		(1 <<  _PAGE_FILE_SHIFT)

 /*
  * And these are the hardware TLB bits
  */
 #define _PAGE_GLOBAL_SHIFT	8
 #define _PAGE_GLOBAL		(1 <<  _PAGE_GLOBAL_SHIFT)
 #define _PAGE_VALID_SHIFT	9
 #define _PAGE_VALID		(1 <<  _PAGE_VALID_SHIFT)
 #define _PAGE_SILENT_READ	(1 <<  _PAGE_VALID_SHIFT)	/* synonym  */
 #define _PAGE_DIRTY_SHIFT	10
 #define _PAGE_DIRTY		(1 << _PAGE_DIRTY_SHIFT)
 #define _PAGE_SILENT_WRITE	(1 << _PAGE_DIRTY_SHIFT)
 #define _CACHE_UNCACHED_SHIFT	11
 #define _CACHE_UNCACHED		(1 << _CACHE_UNCACHED_SHIFT)
 #define _CACHE_MASK		(1 << _CACHE_UNCACHED_SHIFT)

 #else /* 'Normal' r4K case */
 /*
  * When using the RI/XI bit support, we have 13 bits of flags below
  * the physical address. The RI/XI bits are placed such that a SRL 5
  * can strip off the software bits, then a ROTR 2 can move the RI/XI
  * into bits [63:62]. This also limits physical address to 56 bits,
  * which is more than we need right now.
  */

 /*
  * The following bits are implemented in software
  *
  * _PAGE_READ / _PAGE_READ_SHIFT should be unused if cpu_has_rixi.
  * _PAGE_FILE semantics: set:pagecache unset:swap
  */
 #define _PAGE_PRESENT_SHIFT	(0)
 #define _PAGE_PRESENT		(1 << _PAGE_PRESENT_SHIFT)
 #define _PAGE_READ_SHIFT	(cpu_has_rixi ? _PAGE_PRESENT_SHIFT : _PAGE_PRESENT_SHIFT + 1)
 #define _PAGE_READ ({BUG_ON(cpu_has_rixi); 1 << _PAGE_READ_SHIFT; })
 #define _PAGE_WRITE_SHIFT	(_PAGE_READ_SHIFT + 1)
 #define _PAGE_WRITE		(1 << _PAGE_WRITE_SHIFT)
 #define _PAGE_ACCESSED_SHIFT	(_PAGE_WRITE_SHIFT + 1)
 #define _PAGE_ACCESSED		(1 << _PAGE_ACCESSED_SHIFT)
 #define _PAGE_MODIFIED_SHIFT	(_PAGE_ACCESSED_SHIFT + 1)
 #define _PAGE_MODIFIED		(1 << _PAGE_MODIFIED_SHIFT)
 #define _PAGE_FILE		(_PAGE_MODIFIED)

 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 /* huge tlb page */
 #define _PAGE_HUGE_SHIFT	(_PAGE_MODIFIED_SHIFT + 1)
 #define _PAGE_HUGE		(1 << _PAGE_HUGE_SHIFT)
 #else
 #define _PAGE_HUGE_SHIFT	(_PAGE_MODIFIED_SHIFT)
 #define _PAGE_HUGE		({BUG(); 1; })	/* Dummy value */
 #endif

 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 /* huge tlb page */
 #define _PAGE_SPLITTING_SHIFT	(_PAGE_HUGE_SHIFT + 1)
 #define _PAGE_SPLITTING		(1 << _PAGE_SPLITTING_SHIFT)
 #else
 #define _PAGE_SPLITTING_SHIFT	(_PAGE_HUGE_SHIFT)
 #define _PAGE_SPLITTING		({BUG(); 1; })	/* Dummy value */
 #endif

 /* Page cannot be executed */
 #define _PAGE_NO_EXEC_SHIFT	(cpu_has_rixi ? _PAGE_SPLITTING_SHIFT + 1 : _PAGE_SPLITTING_SHIFT)
 #define _PAGE_NO_EXEC		({BUG_ON(!cpu_has_rixi); 1 << _PAGE_NO_EXEC_SHIFT; })

 /* Page cannot be read */
 #define _PAGE_NO_READ_SHIFT	(cpu_has_rixi ? _PAGE_NO_EXEC_SHIFT + 1 : _PAGE_NO_EXEC_SHIFT)
 #define _PAGE_NO_READ		({BUG_ON(!cpu_has_rixi); 1 << _PAGE_NO_READ_SHIFT; })

 #define _PAGE_GLOBAL_SHIFT	(_PAGE_NO_READ_SHIFT + 1)
 #define _PAGE_GLOBAL		(1 << _PAGE_GLOBAL_SHIFT)

 #define _PAGE_VALID_SHIFT	(_PAGE_GLOBAL_SHIFT + 1)
 #define _PAGE_VALID		(1 << _PAGE_VALID_SHIFT)
 /* synonym		   */
 #define _PAGE_SILENT_READ	(_PAGE_VALID)

 /* The MIPS dirty bit	   */
 #define _PAGE_DIRTY_SHIFT	(_PAGE_VALID_SHIFT + 1)
 #define _PAGE_DIRTY		(1 << _PAGE_DIRTY_SHIFT)
 #define _PAGE_SILENT_WRITE	(_PAGE_DIRTY)

 #define _CACHE_SHIFT		(_PAGE_DIRTY_SHIFT + 1)
 #define _CACHE_MASK		(7 << _CACHE_SHIFT)

 #define _PFN_SHIFT		(PAGE_SHIFT - 12 + _CACHE_SHIFT + 3)

 #endif /* defined(CONFIG_64BIT_PHYS_ADDR && defined(CONFIG_CPU_MIPS32) */

 #ifndef _PFN_SHIFT
 #define _PFN_SHIFT		    PAGE_SHIFT
 #endif
 #define _PFN_MASK		(~((1 << (_PFN_SHIFT)) - 1))

 #ifndef _PAGE_NO_READ
 #define _PAGE_NO_READ ({BUG(); 0; })
 #define _PAGE_NO_READ_SHIFT ({BUG(); 0; })
 #endif
 #ifndef _PAGE_NO_EXEC
 #define _PAGE_NO_EXEC ({BUG(); 0; })
 #endif
 #ifndef _PAGE_GLOBAL_SHIFT
 #define _PAGE_GLOBAL_SHIFT ilog2(_PAGE_GLOBAL)
 #endif


 #ifndef __ASSEMBLY__
 /*
  * pte_to_entrylo converts a page table entry (PTE) into a Mips
  * entrylo0/1 value.
  */
 static inline uint64_t pte_to_entrylo(unsigned long pte_val)
 {
 	if (cpu_has_rixi) {
 		int sa;
 #ifdef CONFIG_32BIT
 		sa = 31 - _PAGE_NO_READ_SHIFT;
 #else
 		sa = 63 - _PAGE_NO_READ_SHIFT;
 #endif
 		/*
 		 * C has no way to express that this is a DSRL
 		 * _PAGE_NO_EXEC_SHIFT followed by a ROTR 2.  Luckily
 		 * in the fast path this is done in assembly
 		 */
 		return (pte_val >> _PAGE_GLOBAL_SHIFT) |
 			((pte_val & (_PAGE_NO_EXEC | _PAGE_NO_READ)) << sa);
 	}

 	return pte_val >> _PAGE_GLOBAL_SHIFT;
 }
 #endif

 /*
  * Cache attributes
  */
 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)

 #define _CACHE_CACHABLE_NONCOHERENT 0

 #elif defined(CONFIG_CPU_SB1)

 /* No penalty for being coherent on the SB1, so just
    use it for "noncoherent" spaces, too.  Shouldn't hurt. */

 #define _CACHE_UNCACHED		    (2<<_CACHE_SHIFT)
 #define _CACHE_CACHABLE_COW	    (5<<_CACHE_SHIFT)
 #define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT)
 #define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)

 #else

 #define _CACHE_CACHABLE_NO_WA	    (0<<_CACHE_SHIFT)  /* R4600 only	  */
 #define _CACHE_CACHABLE_WA	    (1<<_CACHE_SHIFT)  /* R4600 only	  */
 #define _CACHE_UNCACHED		    (2<<_CACHE_SHIFT)  /* R4[0246]00	  */
 #define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT)  /* R4[0246]00	  */
 #define _CACHE_CACHABLE_CE	    (4<<_CACHE_SHIFT)  /* R4[04]00MC only */
 #define _CACHE_CACHABLE_COW	    (5<<_CACHE_SHIFT)  /* R4[04]00MC only */
 #define _CACHE_CACHABLE_COHERENT    (5<<_CACHE_SHIFT)  /* MIPS32R2 CMP	  */
 #define _CACHE_CACHABLE_CUW	    (6<<_CACHE_SHIFT)  /* R4[04]00MC only */
 #define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)  /* R10000 only	  */

 #endif

 #define __READABLE	(_PAGE_SILENT_READ | _PAGE_ACCESSED | (cpu_has_rixi ? 0 : _PAGE_READ))
 #define __WRITEABLE	(_PAGE_WRITE | _PAGE_SILENT_WRITE | _PAGE_MODIFIED)

 #define _PAGE_CHG_MASK	(_PFN_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED | _CACHE_MASK)

 #endif /* _ASM_PGTABLE_BITS_H */
	/*
	* This file is subject to the terms and conditions of the GNU General Public
	* License. See the file "COPYING" in the main directory of this archive
	* for more details.
	*
	* Copyright (C) 1994 - 2002 by Ralf Baechle
	* Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
	* Copyright (C) 2002 Maciej W. Rozycki
	*/
	#ifndef _ASM_PGTABLE_BITS_H
	#define _ASM_PGTABLE_BITS_H


	/*
	* Note that we shift the lower 32bits of each EntryLo[01] entry
	* 6 bits to the left. That way we can convert the PFN into the
	* physical address by a single 'and' operation and gain 6 additional
	* bits for storing information which isn't present in a normal
	* MIPS page table.
	*
	* Similar to the Alpha port, we need to keep track of the ref
	* and mod bits in software. We have a software "yeah you can read
	* from this page" bit, and a hardware one which actually lets the
	* process read from the page. On the same token we have a software
	* writable bit and the real hardware one which actually lets the
	* process write to the page, this keeps a mod bit via the hardware
	* dirty bit.
	*
	* Certain revisions of the R4000 and R5000 have a bug where if a
	* certain sequence occurs in the last 3 instructions of an executable
	* page, and the following page is not mapped, the cpu can do
	* unpredictable things. The code (when it is written) to deal with
	* this problem will be in the update_mmu_cache() code for the r4k.
	*/
	#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)

	/*
	* The following bits are directly used by the TLB hardware
	*/
	#define _PAGE_R4KBUG (1 << 0) /* workaround for r4k bug */
	#define _PAGE_GLOBAL (1 << 0)
	#define _PAGE_VALID_SHIFT 1
	#define _PAGE_VALID (1 << _PAGE_VALID_SHIFT)
	#define _PAGE_SILENT_READ (1 << 1) /* synonym */
	#define _PAGE_DIRTY_SHIFT 2
	#define _PAGE_DIRTY (1 << _PAGE_DIRTY_SHIFT) /* The MIPS dirty bit */
	#define _PAGE_SILENT_WRITE (1 << 2)
	#define _CACHE_SHIFT 3
	#define _CACHE_MASK (7 << 3)

	/*
	* The following bits are implemented in software
	*
	* _PAGE_FILE semantics: set:pagecache unset:swap
	*/
	#define _PAGE_PRESENT_SHIFT 6
	#define _PAGE_PRESENT (1 << _PAGE_PRESENT_SHIFT)
	#define _PAGE_READ_SHIFT 7
	#define _PAGE_READ (1 << _PAGE_READ_SHIFT)
	#define _PAGE_WRITE_SHIFT 8
	#define _PAGE_WRITE (1 << _PAGE_WRITE_SHIFT)
	#define _PAGE_ACCESSED_SHIFT 9
	#define _PAGE_ACCESSED (1 << _PAGE_ACCESSED_SHIFT)
	#define _PAGE_MODIFIED_SHIFT 10
	#define _PAGE_MODIFIED (1 << _PAGE_MODIFIED_SHIFT)

	#define _PAGE_FILE (1 << 10)

	#elif defined(CONFIG_CPU_R3000) \|\| defined(CONFIG_CPU_TX39XX)

	/*
	* The following are implemented by software
	*
	* _PAGE_FILE semantics: set:pagecache unset:swap
	*/
	#define _PAGE_PRESENT_SHIFT 0
	#define _PAGE_PRESENT (1 << _PAGE_PRESENT_SHIFT)
	#define _PAGE_READ_SHIFT 1
	#define _PAGE_READ (1 << _PAGE_READ_SHIFT)
	#define _PAGE_WRITE_SHIFT 2
	#define _PAGE_WRITE (1 << _PAGE_WRITE_SHIFT)
	#define _PAGE_ACCESSED_SHIFT 3
	#define _PAGE_ACCESSED (1 << _PAGE_ACCESSED_SHIFT)
	#define _PAGE_MODIFIED_SHIFT 4
	#define _PAGE_MODIFIED (1 << _PAGE_MODIFIED_SHIFT)
	#define _PAGE_FILE_SHIFT 4
	#define _PAGE_FILE (1 << _PAGE_FILE_SHIFT)

	/*
	* And these are the hardware TLB bits
	*/
	#define _PAGE_GLOBAL_SHIFT 8
	#define _PAGE_GLOBAL (1 << _PAGE_GLOBAL_SHIFT)
	#define _PAGE_VALID_SHIFT 9
	#define _PAGE_VALID (1 << _PAGE_VALID_SHIFT)
	#define _PAGE_SILENT_READ (1 << _PAGE_VALID_SHIFT) /* synonym */
	#define _PAGE_DIRTY_SHIFT 10
	#define _PAGE_DIRTY (1 << _PAGE_DIRTY_SHIFT)
	#define _PAGE_SILENT_WRITE (1 << _PAGE_DIRTY_SHIFT)
	#define _CACHE_UNCACHED_SHIFT 11
	#define _CACHE_UNCACHED (1 << _CACHE_UNCACHED_SHIFT)
	#define _CACHE_MASK (1 << _CACHE_UNCACHED_SHIFT)

	#else /* 'Normal' r4K case */
	/*
	* When using the RI/XI bit support, we have 13 bits of flags below
	* the physical address. The RI/XI bits are placed such that a SRL 5
	* can strip off the software bits, then a ROTR 2 can move the RI/XI
	* into bits [63:62]. This also limits physical address to 56 bits,
	* which is more than we need right now.
	*/

	/*
	* The following bits are implemented in software
	*
	* _PAGE_READ / _PAGE_READ_SHIFT should be unused if cpu_has_rixi.
	* _PAGE_FILE semantics: set:pagecache unset:swap
	*/
	#define _PAGE_PRESENT_SHIFT (0)
	#define _PAGE_PRESENT (1 << _PAGE_PRESENT_SHIFT)
	#define _PAGE_READ_SHIFT (cpu_has_rixi ? _PAGE_PRESENT_SHIFT : _PAGE_PRESENT_SHIFT + 1)
	#define _PAGE_READ ({BUG_ON(cpu_has_rixi); 1 << _PAGE_READ_SHIFT; })
	#define _PAGE_WRITE_SHIFT (_PAGE_READ_SHIFT + 1)
	#define _PAGE_WRITE (1 << _PAGE_WRITE_SHIFT)
	#define _PAGE_ACCESSED_SHIFT (_PAGE_WRITE_SHIFT + 1)
	#define _PAGE_ACCESSED (1 << _PAGE_ACCESSED_SHIFT)
	#define _PAGE_MODIFIED_SHIFT (_PAGE_ACCESSED_SHIFT + 1)
	#define _PAGE_MODIFIED (1 << _PAGE_MODIFIED_SHIFT)
	#define _PAGE_FILE (_PAGE_MODIFIED)

	#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
	/* huge tlb page */
	#define _PAGE_HUGE_SHIFT (_PAGE_MODIFIED_SHIFT + 1)
	#define _PAGE_HUGE (1 << _PAGE_HUGE_SHIFT)
	#else
	#define _PAGE_HUGE_SHIFT (_PAGE_MODIFIED_SHIFT)
	#define _PAGE_HUGE ({BUG(); 1; }) /* Dummy value */
	#endif

	#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
	/* huge tlb page */
	#define _PAGE_SPLITTING_SHIFT (_PAGE_HUGE_SHIFT + 1)
	#define _PAGE_SPLITTING (1 << _PAGE_SPLITTING_SHIFT)
	#else
	#define _PAGE_SPLITTING_SHIFT (_PAGE_HUGE_SHIFT)
	#define _PAGE_SPLITTING ({BUG(); 1; }) /* Dummy value */
	#endif

	/* Page cannot be executed */
	#define _PAGE_NO_EXEC_SHIFT (cpu_has_rixi ? _PAGE_SPLITTING_SHIFT + 1 : _PAGE_SPLITTING_SHIFT)
	#define _PAGE_NO_EXEC ({BUG_ON(!cpu_has_rixi); 1 << _PAGE_NO_EXEC_SHIFT; })

	/* Page cannot be read */
	#define _PAGE_NO_READ_SHIFT (cpu_has_rixi ? _PAGE_NO_EXEC_SHIFT + 1 : _PAGE_NO_EXEC_SHIFT)
	#define _PAGE_NO_READ ({BUG_ON(!cpu_has_rixi); 1 << _PAGE_NO_READ_SHIFT; })

	#define _PAGE_GLOBAL_SHIFT (_PAGE_NO_READ_SHIFT + 1)
	#define _PAGE_GLOBAL (1 << _PAGE_GLOBAL_SHIFT)

	#define _PAGE_VALID_SHIFT (_PAGE_GLOBAL_SHIFT + 1)
	#define _PAGE_VALID (1 << _PAGE_VALID_SHIFT)
	/* synonym */
	#define _PAGE_SILENT_READ (_PAGE_VALID)

	/* The MIPS dirty bit */
	#define _PAGE_DIRTY_SHIFT (_PAGE_VALID_SHIFT + 1)
	#define _PAGE_DIRTY (1 << _PAGE_DIRTY_SHIFT)
	#define _PAGE_SILENT_WRITE (_PAGE_DIRTY)

	#define _CACHE_SHIFT (_PAGE_DIRTY_SHIFT + 1)
	#define _CACHE_MASK (7 << _CACHE_SHIFT)

	#define _PFN_SHIFT (PAGE_SHIFT - 12 + _CACHE_SHIFT + 3)

	#endif /* defined(CONFIG_64BIT_PHYS_ADDR && defined(CONFIG_CPU_MIPS32) */

	#ifndef _PFN_SHIFT
	#define _PFN_SHIFT PAGE_SHIFT
	#endif
	#define _PFN_MASK (~((1 << (_PFN_SHIFT)) - 1))

	#ifndef _PAGE_NO_READ
	#define _PAGE_NO_READ ({BUG(); 0; })
	#define _PAGE_NO_READ_SHIFT ({BUG(); 0; })
	#endif
	#ifndef _PAGE_NO_EXEC
	#define _PAGE_NO_EXEC ({BUG(); 0; })
	#endif
	#ifndef _PAGE_GLOBAL_SHIFT
	#define _PAGE_GLOBAL_SHIFT ilog2(_PAGE_GLOBAL)
	#endif


	#ifndef __ASSEMBLY__
	/*
	* pte_to_entrylo converts a page table entry (PTE) into a Mips
	* entrylo0/1 value.
	*/
	static inline uint64_t pte_to_entrylo(unsigned long pte_val)
	{
	if (cpu_has_rixi) {
	int sa;
	#ifdef CONFIG_32BIT
	sa = 31 - _PAGE_NO_READ_SHIFT;
	#else
	sa = 63 - _PAGE_NO_READ_SHIFT;
	#endif
	/*
	* C has no way to express that this is a DSRL
	* _PAGE_NO_EXEC_SHIFT followed by a ROTR 2. Luckily
	* in the fast path this is done in assembly
	*/
	return (pte_val >> _PAGE_GLOBAL_SHIFT) \|
	((pte_val & (_PAGE_NO_EXEC \| _PAGE_NO_READ)) << sa);
	}

	return pte_val >> _PAGE_GLOBAL_SHIFT;
	}
	#endif

	/*
	* Cache attributes
	*/
	#if defined(CONFIG_CPU_R3000) \|\| defined(CONFIG_CPU_TX39XX)

	#define _CACHE_CACHABLE_NONCOHERENT 0

	#elif defined(CONFIG_CPU_SB1)

	/* No penalty for being coherent on the SB1, so just
	use it for "noncoherent" spaces, too. Shouldn't hurt. */

	#define _CACHE_UNCACHED (2<<_CACHE_SHIFT)
	#define _CACHE_CACHABLE_COW (5<<_CACHE_SHIFT)
	#define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT)
	#define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)

	#else

	#define _CACHE_CACHABLE_NO_WA (0<<_CACHE_SHIFT) /* R4600 only */
	#define _CACHE_CACHABLE_WA (1<<_CACHE_SHIFT) /* R4600 only */
	#define _CACHE_UNCACHED (2<<_CACHE_SHIFT) /* R4[0246]00 */
	#define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT) /* R4[0246]00 */
	#define _CACHE_CACHABLE_CE (4<<_CACHE_SHIFT) /* R4[04]00MC only */
	#define _CACHE_CACHABLE_COW (5<<_CACHE_SHIFT) /* R4[04]00MC only */
	#define _CACHE_CACHABLE_COHERENT (5<<_CACHE_SHIFT) /* MIPS32R2 CMP */
	#define _CACHE_CACHABLE_CUW (6<<_CACHE_SHIFT) /* R4[04]00MC only */
	#define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT) /* R10000 only */

	#endif

	#define __READABLE (_PAGE_SILENT_READ \| _PAGE_ACCESSED \| (cpu_has_rixi ? 0 : _PAGE_READ))
	#define __WRITEABLE (_PAGE_WRITE \| _PAGE_SILENT_WRITE \| _PAGE_MODIFIED)

	#define _PAGE_CHG_MASK (_PFN_MASK \| _PAGE_ACCESSED \| _PAGE_MODIFIED \| _CACHE_MASK)

	#endif /* _ASM_PGTABLE_BITS_H */