1/*
  2 * CRIS MMU constants and PTE layout
  3 */
  4
  5#ifndef _CRIS_ARCH_MMU_H
  6#define _CRIS_ARCH_MMU_H
  7
  8/* type used in struct mm to couple an MMU context to an active mm */
  9
 10typedef struct
 11{
 12  unsigned int page_id;
 13} mm_context_t;
 14
 15/* kernel memory segments */
 16
 17#define KSEG_F 0xf0000000UL
 18#define KSEG_E 0xe0000000UL
 19#define KSEG_D 0xd0000000UL
 20#define KSEG_C 0xc0000000UL
 21#define KSEG_B 0xb0000000UL
 22#define KSEG_A 0xa0000000UL
 23#define KSEG_9 0x90000000UL
 24#define KSEG_8 0x80000000UL
 25#define KSEG_7 0x70000000UL
 26#define KSEG_6 0x60000000UL
 27#define KSEG_5 0x50000000UL
 28#define KSEG_4 0x40000000UL
 29#define KSEG_3 0x30000000UL
 30#define KSEG_2 0x20000000UL
 31#define KSEG_1 0x10000000UL
 32#define KSEG_0 0x00000000UL
 33
 34/* CRIS PTE bits (see R_TLB_LO in the register description)
 35 *
 36 *   Bit:  31     30-13 12-------4    3        2       1       0
 37 *         _______________________________________________________
 38 *        | cache |pfn | reserved | global | valid | kernel | we  |
 39 *        |_______|____|__________|________|_______|________|_____|
 40 *
 41 * (pfn = physical frame number)
 42 */
 43
 44/* Real HW-based PTE bits. We use some synonym names so that
 45 * things become less confusing in combination with the SW-based
 46 * bits further below.
 47 *
 48 */
 49
 50#define _PAGE_WE	   (1<<0) /* page is write-enabled */
 51#define _PAGE_SILENT_WRITE (1<<0) /* synonym */
 52#define _PAGE_KERNEL	   (1<<1) /* page is kernel only */
 53#define _PAGE_VALID	   (1<<2) /* page is valid */
 54#define _PAGE_SILENT_READ  (1<<2) /* synonym */
 55#define _PAGE_GLOBAL       (1<<3) /* global page - context is ignored */
 56#define _PAGE_NO_CACHE	   (1<<31) /* part of the uncached memory map */
 57
 58/* Bits the HW doesn't care about but the kernel uses them in SW */
 59
 60#define _PAGE_PRESENT   (1<<4)  /* page present in memory */
 61#define _PAGE_FILE      (1<<5)  /* set: pagecache, unset: swap (when !PRESENT) */
 62#define _PAGE_ACCESSED	(1<<5)  /* simulated in software using valid bit */
 63#define _PAGE_MODIFIED	(1<<6)  /* simulated in software using we bit */
 64#define _PAGE_READ      (1<<7)  /* read-enabled */
 65#define _PAGE_WRITE     (1<<8)  /* write-enabled */
 66
 67/* Define some higher level generic page attributes. */
 68
 69#define __READABLE      (_PAGE_READ | _PAGE_SILENT_READ | _PAGE_ACCESSED)
 70#define __WRITEABLE     (_PAGE_WRITE | _PAGE_SILENT_WRITE | _PAGE_MODIFIED)
 71
 72#define _PAGE_TABLE     (_PAGE_PRESENT | __READABLE | __WRITEABLE)
 73#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED)
 74
 75#define PAGE_NONE       __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
 76#define PAGE_SHARED     __pgprot(_PAGE_PRESENT | __READABLE | _PAGE_WRITE | \
 77				 _PAGE_ACCESSED)
 78#define PAGE_COPY       __pgprot(_PAGE_PRESENT | __READABLE)  // | _PAGE_COW
 79#define PAGE_READONLY   __pgprot(_PAGE_PRESENT | __READABLE)
 80#define PAGE_KERNEL     __pgprot(_PAGE_GLOBAL | _PAGE_KERNEL | \
 81				 _PAGE_PRESENT | __READABLE | __WRITEABLE)
 82#define _KERNPG_TABLE   (_PAGE_TABLE | _PAGE_KERNEL)
 83
 84/*
 85 * CRIS can't do page protection for execute, and considers read the same.
 86 * Also, write permissions imply read permissions. This is the closest we can
 87 * get..
 88 */
 89
 90#define __P000	PAGE_NONE
 91#define __P001	PAGE_READONLY
 92#define __P010	PAGE_COPY
 93#define __P011	PAGE_COPY
 94#define __P100	PAGE_READONLY
 95#define __P101	PAGE_READONLY
 96#define __P110	PAGE_COPY
 97#define __P111	PAGE_COPY
 98
 99#define __S000	PAGE_NONE
100#define __S001	PAGE_READONLY
101#define __S010	PAGE_SHARED
102#define __S011	PAGE_SHARED
103#define __S100	PAGE_READONLY
104#define __S101	PAGE_READONLY
105#define __S110	PAGE_SHARED
106#define __S111	PAGE_SHARED
107
108#define PTE_FILE_MAX_BITS	26
109
110#endif