| /* |
| * 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 |
| |
| #include <linux/config.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. |
| */ |
| #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 */ |
| |
| #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) |
| |
| #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) |
| #define _CACHE_CACHABLE_NONCOHERENT 0 |
| |
| #else |
| #define _PAGE_R4KBUG (1<<5) /* workaround for r4k bug */ |
| #define _PAGE_GLOBAL (1<<6) |
| #define _PAGE_VALID (1<<7) |
| #define _PAGE_SILENT_READ (1<<7) /* synonym */ |
| #define _PAGE_DIRTY (1<<8) /* The MIPS dirty bit */ |
| #define _PAGE_SILENT_WRITE (1<<8) |
| #define _CACHE_MASK (7<<9) |
| |
| #if 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<<9) |
| #define _CACHE_CACHABLE_COW (5<<9) |
| #define _CACHE_CACHABLE_NONCOHERENT (5<<9) |
| #define _CACHE_UNCACHED_ACCELERATED (7<<9) |
| |
| #else |
| |
| #define _CACHE_CACHABLE_NO_WA (0<<9) /* R4600 only */ |
| #define _CACHE_CACHABLE_WA (1<<9) /* R4600 only */ |
| #define _CACHE_UNCACHED (2<<9) /* R4[0246]00 */ |
| #define _CACHE_CACHABLE_NONCOHERENT (3<<9) /* R4[0246]00 */ |
| #define _CACHE_CACHABLE_CE (4<<9) /* R4[04]00MC only */ |
| #define _CACHE_CACHABLE_COW (5<<9) /* R4[04]00MC only */ |
| #define _CACHE_CACHABLE_CUW (6<<9) /* R4[04]00MC only */ |
| #define _CACHE_UNCACHED_ACCELERATED (7<<9) /* R10000 only */ |
| |
| #endif |
| #endif |
| |
| #define __READABLE (_PAGE_READ | _PAGE_SILENT_READ | _PAGE_ACCESSED) |
| #define __WRITEABLE (_PAGE_WRITE | _PAGE_SILENT_WRITE | _PAGE_MODIFIED) |
| |
| #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED | _CACHE_MASK) |
| |
| #ifdef CONFIG_MIPS_UNCACHED |
| #define PAGE_CACHABLE_DEFAULT _CACHE_UNCACHED |
| #elif defined(CONFIG_NONCOHERENT_IO) |
| #define PAGE_CACHABLE_DEFAULT _CACHE_CACHABLE_NONCOHERENT |
| #else |
| #define PAGE_CACHABLE_DEFAULT _CACHE_CACHABLE_COW |
| #endif |
| |
| #define CONF_CM_DEFAULT (PAGE_CACHABLE_DEFAULT >> 9) |
| |
| #endif /* _ASM_PGTABLE_BITS_H */ |
