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Diffstat (limited to 'arch/mips/include/asm/pgtable-bits.h')
| -rw-r--r-- | arch/mips/include/asm/pgtable-bits.h | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/arch/mips/include/asm/pgtable-bits.h b/arch/mips/include/asm/pgtable-bits.h new file mode 100644 index 00000000..e9fe7e97 --- /dev/null +++ b/arch/mips/include/asm/pgtable-bits.h @@ -0,0 +1,228 @@ +/* + * 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 */ |