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_ACCESSED	(1<<5)  /* simulated in software using valid bit */
62#define _PAGE_MODIFIED	(1<<6)  /* simulated in software using we bit */
63#define _PAGE_READ      (1<<7)  /* read-enabled */
64#define _PAGE_WRITE     (1<<8)  /* write-enabled */
65
66/* Define some higher level generic page attributes. */
67
68#define __READABLE      (_PAGE_READ | _PAGE_SILENT_READ | _PAGE_ACCESSED)
69#define __WRITEABLE     (_PAGE_WRITE | _PAGE_SILENT_WRITE | _PAGE_MODIFIED)
70
71#define _PAGE_TABLE     (_PAGE_PRESENT | __READABLE | __WRITEABLE)
72#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED)
73
74#define PAGE_NONE       __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
75#define PAGE_SHARED     __pgprot(_PAGE_PRESENT | __READABLE | _PAGE_WRITE | \
76				 _PAGE_ACCESSED)
77#define PAGE_COPY       __pgprot(_PAGE_PRESENT | __READABLE)  // | _PAGE_COW
78#define PAGE_READONLY   __pgprot(_PAGE_PRESENT | __READABLE)
79#define PAGE_KERNEL     __pgprot(_PAGE_GLOBAL | _PAGE_KERNEL | \
80				 _PAGE_PRESENT | __READABLE | __WRITEABLE)
81#define _KERNPG_TABLE   (_PAGE_TABLE | _PAGE_KERNEL)
82
83/*
84 * CRIS can't do page protection for execute, and considers read the same.
85 * Also, write permissions imply read permissions. This is the closest we can
86 * get..
87 */
88
89#define __P000	PAGE_NONE
90#define __P001	PAGE_READONLY
91#define __P010	PAGE_COPY
92#define __P011	PAGE_COPY
93#define __P100	PAGE_READONLY
94#define __P101	PAGE_READONLY
95#define __P110	PAGE_COPY
96#define __P111	PAGE_COPY
97
98#define __S000	PAGE_NONE
99#define __S001	PAGE_READONLY
100#define __S010	PAGE_SHARED
101#define __S011	PAGE_SHARED
102#define __S100	PAGE_READONLY
103#define __S101	PAGE_READONLY
104#define __S110	PAGE_SHARED
105#define __S111	PAGE_SHARED
106
107#endif
108