pgtable-bits.h
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/*
* 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)
#define _PAGE_PRESENT (1<<6) /* implemented in software */
#define _PAGE_READ (1<<7) /* implemented in software */
#define _PAGE_WRITE (1<<8) /* implemented in software */
#define _PAGE_ACCESSED (1<<9) /* implemented in software */
#define _PAGE_MODIFIED (1<<10) /* implemented in software */
#define _PAGE_FILE (1<<10) /* set:pagecache unset:swap */
#define _PAGE_R4KBUG (1<<0) /* workaround for r4k bug */
#define _PAGE_GLOBAL (1<<0)
#define _PAGE_VALID (1<<1)
#define _PAGE_SILENT_READ (1<<1) /* synonym */
#define _PAGE_DIRTY (1<<2) /* The MIPS dirty bit */
#define _PAGE_SILENT_WRITE (1<<2)
#define _CACHE_SHIFT 3
#define _CACHE_MASK (7<<3)
#elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
#define _PAGE_PRESENT (1<<0) /* implemented in software */
#define _PAGE_READ (1<<1) /* implemented in software */
#define _PAGE_WRITE (1<<2) /* implemented in software */
#define _PAGE_ACCESSED (1<<3) /* implemented in software */
#define _PAGE_MODIFIED (1<<4) /* implemented in software */
#define _PAGE_FILE (1<<4) /* set:pagecache unset:swap */
#define _PAGE_GLOBAL (1<<8)
#define _PAGE_VALID (1<<9)
#define _PAGE_SILENT_READ (1<<9) /* synonym */
#define _PAGE_DIRTY (1<<10) /* The MIPS dirty bit */
#define _PAGE_SILENT_WRITE (1<<10)
#define _CACHE_UNCACHED (1<<11)
#define _CACHE_MASK (1<<11)
#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.
*/
/* implemented in software */
#define _PAGE_PRESENT_SHIFT (0)
#define _PAGE_PRESENT (1 << _PAGE_PRESENT_SHIFT)
/* implemented in software, should be unused if kernel_uses_smartmips_rixi. */
#define _PAGE_READ_SHIFT (kernel_uses_smartmips_rixi ? _PAGE_PRESENT_SHIFT : _PAGE_PRESENT_SHIFT + 1)
#define _PAGE_READ ({if (kernel_uses_smartmips_rixi) BUG(); 1 << _PAGE_READ_SHIFT; })
/* implemented in software */
#define _PAGE_WRITE_SHIFT (_PAGE_READ_SHIFT + 1)
#define _PAGE_WRITE (1 << _PAGE_WRITE_SHIFT)
/* implemented in software */
#define _PAGE_ACCESSED_SHIFT (_PAGE_WRITE_SHIFT + 1)
#define _PAGE_ACCESSED (1 << _PAGE_ACCESSED_SHIFT)
/* implemented in software */
#define _PAGE_MODIFIED_SHIFT (_PAGE_ACCESSED_SHIFT + 1)
#define _PAGE_MODIFIED (1 << _PAGE_MODIFIED_SHIFT)
/* set:pagecache unset:swap */
#define _PAGE_FILE (_PAGE_MODIFIED)
#ifdef CONFIG_HUGETLB_PAGE
/* 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
/* Page cannot be executed */
#define _PAGE_NO_EXEC_SHIFT (kernel_uses_smartmips_rixi ? _PAGE_HUGE_SHIFT + 1 : _PAGE_HUGE_SHIFT)
#define _PAGE_NO_EXEC ({if (!kernel_uses_smartmips_rixi) BUG(); 1 << _PAGE_NO_EXEC_SHIFT; })
/* Page cannot be read */
#define _PAGE_NO_READ_SHIFT (kernel_uses_smartmips_rixi ? _PAGE_NO_EXEC_SHIFT + 1 : _PAGE_NO_EXEC_SHIFT)
#define _PAGE_NO_READ ({if (!kernel_uses_smartmips_rixi) BUG(); 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 (kernel_uses_smartmips_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)
#elif defined(CONFIG_CPU_RM9000)
#define _CACHE_WT (0<<_CACHE_SHIFT)
#define _CACHE_WTWA (1<<_CACHE_SHIFT)
#define _CACHE_UC_B (2<<_CACHE_SHIFT)
#define _CACHE_WB (3<<_CACHE_SHIFT)
#define _CACHE_CWBEA (4<<_CACHE_SHIFT)
#define _CACHE_CWB (5<<_CACHE_SHIFT)
#define _CACHE_UCNB (6<<_CACHE_SHIFT)
#define _CACHE_FPC (7<<_CACHE_SHIFT)
#define _CACHE_UNCACHED _CACHE_UC_B
#define _CACHE_CACHABLE_NONCOHERENT _CACHE_WB
#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 | (kernel_uses_smartmips_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 */