aboutsummaryrefslogtreecommitdiffstats
path: root/arch
diff options
context:
space:
mode:
authorCatalin Marinas <catalin.marinas@arm.com>2011-09-05 12:41:02 -0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-10-06 10:40:05 -0400
commit17f57211969bddca2e922299a2530b1c65ccabfa (patch)
treef48835b326774f0a7a695d288a86fcfca5f55edf /arch
parente73fc88e19d74fd4dd664cff45b88caab8cde45c (diff)
ARM: 7075/1: LPAE: Factor out 2-level page table definitions into separate files
This patch moves page table definitions from asm/page.h, asm/pgtable.h and asm/ptgable-hwdef.h into corresponding *-2level* files. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/page.h42
-rw-r--r--arch/arm/include/asm/pgtable-2level-hwdef.h91
-rw-r--r--arch/arm/include/asm/pgtable-2level-types.h64
-rw-r--r--arch/arm/include/asm/pgtable-2level.h143
-rw-r--r--arch/arm/include/asm/pgtable-hwdef.h77
-rw-r--r--arch/arm/include/asm/pgtable.h135
6 files changed, 302 insertions, 250 deletions
diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h
index ac75d0848889..ca94653f1ecb 100644
--- a/arch/arm/include/asm/page.h
+++ b/arch/arm/include/asm/page.h
@@ -151,47 +151,7 @@ extern void __cpu_copy_user_highpage(struct page *to, struct page *from,
151#define clear_page(page) memset((void *)(page), 0, PAGE_SIZE) 151#define clear_page(page) memset((void *)(page), 0, PAGE_SIZE)
152extern void copy_page(void *to, const void *from); 152extern void copy_page(void *to, const void *from);
153 153
154typedef unsigned long pteval_t; 154#include <asm/pgtable-2level-types.h>
155
156#undef STRICT_MM_TYPECHECKS
157
158#ifdef STRICT_MM_TYPECHECKS
159/*
160 * These are used to make use of C type-checking..
161 */
162typedef struct { pteval_t pte; } pte_t;
163typedef struct { unsigned long pmd; } pmd_t;
164typedef struct { unsigned long pgd[2]; } pgd_t;
165typedef struct { unsigned long pgprot; } pgprot_t;
166
167#define pte_val(x) ((x).pte)
168#define pmd_val(x) ((x).pmd)
169#define pgd_val(x) ((x).pgd[0])
170#define pgprot_val(x) ((x).pgprot)
171
172#define __pte(x) ((pte_t) { (x) } )
173#define __pmd(x) ((pmd_t) { (x) } )
174#define __pgprot(x) ((pgprot_t) { (x) } )
175
176#else
177/*
178 * .. while these make it easier on the compiler
179 */
180typedef pteval_t pte_t;
181typedef unsigned long pmd_t;
182typedef unsigned long pgd_t[2];
183typedef unsigned long pgprot_t;
184
185#define pte_val(x) (x)
186#define pmd_val(x) (x)
187#define pgd_val(x) ((x)[0])
188#define pgprot_val(x) (x)
189
190#define __pte(x) (x)
191#define __pmd(x) (x)
192#define __pgprot(x) (x)
193
194#endif /* STRICT_MM_TYPECHECKS */
195 155
196#endif /* CONFIG_MMU */ 156#endif /* CONFIG_MMU */
197 157
diff --git a/arch/arm/include/asm/pgtable-2level-hwdef.h b/arch/arm/include/asm/pgtable-2level-hwdef.h
new file mode 100644
index 000000000000..436529c1cda2
--- /dev/null
+++ b/arch/arm/include/asm/pgtable-2level-hwdef.h
@@ -0,0 +1,91 @@
1/*
2 * arch/arm/include/asm/pgtable-2level-hwdef.h
3 *
4 * Copyright (C) 1995-2002 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#ifndef _ASM_PGTABLE_2LEVEL_HWDEF_H
11#define _ASM_PGTABLE_2LEVEL_HWDEF_H
12
13/*
14 * Hardware page table definitions.
15 *
16 * + Level 1 descriptor (PMD)
17 * - common
18 */
19#define PMD_TYPE_MASK (3 << 0)
20#define PMD_TYPE_FAULT (0 << 0)
21#define PMD_TYPE_TABLE (1 << 0)
22#define PMD_TYPE_SECT (2 << 0)
23#define PMD_BIT4 (1 << 4)
24#define PMD_DOMAIN(x) ((x) << 5)
25#define PMD_PROTECTION (1 << 9) /* v5 */
26/*
27 * - section
28 */
29#define PMD_SECT_BUFFERABLE (1 << 2)
30#define PMD_SECT_CACHEABLE (1 << 3)
31#define PMD_SECT_XN (1 << 4) /* v6 */
32#define PMD_SECT_AP_WRITE (1 << 10)
33#define PMD_SECT_AP_READ (1 << 11)
34#define PMD_SECT_TEX(x) ((x) << 12) /* v5 */
35#define PMD_SECT_APX (1 << 15) /* v6 */
36#define PMD_SECT_S (1 << 16) /* v6 */
37#define PMD_SECT_nG (1 << 17) /* v6 */
38#define PMD_SECT_SUPER (1 << 18) /* v6 */
39#define PMD_SECT_AF (0)
40
41#define PMD_SECT_UNCACHED (0)
42#define PMD_SECT_BUFFERED (PMD_SECT_BUFFERABLE)
43#define PMD_SECT_WT (PMD_SECT_CACHEABLE)
44#define PMD_SECT_WB (PMD_SECT_CACHEABLE | PMD_SECT_BUFFERABLE)
45#define PMD_SECT_MINICACHE (PMD_SECT_TEX(1) | PMD_SECT_CACHEABLE)
46#define PMD_SECT_WBWA (PMD_SECT_TEX(1) | PMD_SECT_CACHEABLE | PMD_SECT_BUFFERABLE)
47#define PMD_SECT_NONSHARED_DEV (PMD_SECT_TEX(2))
48
49/*
50 * - coarse table (not used)
51 */
52
53/*
54 * + Level 2 descriptor (PTE)
55 * - common
56 */
57#define PTE_TYPE_MASK (3 << 0)
58#define PTE_TYPE_FAULT (0 << 0)
59#define PTE_TYPE_LARGE (1 << 0)
60#define PTE_TYPE_SMALL (2 << 0)
61#define PTE_TYPE_EXT (3 << 0) /* v5 */
62#define PTE_BUFFERABLE (1 << 2)
63#define PTE_CACHEABLE (1 << 3)
64
65/*
66 * - extended small page/tiny page
67 */
68#define PTE_EXT_XN (1 << 0) /* v6 */
69#define PTE_EXT_AP_MASK (3 << 4)
70#define PTE_EXT_AP0 (1 << 4)
71#define PTE_EXT_AP1 (2 << 4)
72#define PTE_EXT_AP_UNO_SRO (0 << 4)
73#define PTE_EXT_AP_UNO_SRW (PTE_EXT_AP0)
74#define PTE_EXT_AP_URO_SRW (PTE_EXT_AP1)
75#define PTE_EXT_AP_URW_SRW (PTE_EXT_AP1|PTE_EXT_AP0)
76#define PTE_EXT_TEX(x) ((x) << 6) /* v5 */
77#define PTE_EXT_APX (1 << 9) /* v6 */
78#define PTE_EXT_COHERENT (1 << 9) /* XScale3 */
79#define PTE_EXT_SHARED (1 << 10) /* v6 */
80#define PTE_EXT_NG (1 << 11) /* v6 */
81
82/*
83 * - small page
84 */
85#define PTE_SMALL_AP_MASK (0xff << 4)
86#define PTE_SMALL_AP_UNO_SRO (0x00 << 4)
87#define PTE_SMALL_AP_UNO_SRW (0x55 << 4)
88#define PTE_SMALL_AP_URO_SRW (0xaa << 4)
89#define PTE_SMALL_AP_URW_SRW (0xff << 4)
90
91#endif
diff --git a/arch/arm/include/asm/pgtable-2level-types.h b/arch/arm/include/asm/pgtable-2level-types.h
new file mode 100644
index 000000000000..8a01f62d8a16
--- /dev/null
+++ b/arch/arm/include/asm/pgtable-2level-types.h
@@ -0,0 +1,64 @@
1/*
2 * arch/arm/include/asm/pgtable-2level-types.h
3 *
4 * Copyright (C) 1995-2003 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19#ifndef _ASM_PGTABLE_2LEVEL_TYPES_H
20#define _ASM_PGTABLE_2LEVEL_TYPES_H
21
22typedef unsigned long pteval_t;
23
24#undef STRICT_MM_TYPECHECKS
25
26#ifdef STRICT_MM_TYPECHECKS
27/*
28 * These are used to make use of C type-checking..
29 */
30typedef struct { pteval_t pte; } pte_t;
31typedef struct { unsigned long pmd; } pmd_t;
32typedef struct { unsigned long pgd[2]; } pgd_t;
33typedef struct { unsigned long pgprot; } pgprot_t;
34
35#define pte_val(x) ((x).pte)
36#define pmd_val(x) ((x).pmd)
37#define pgd_val(x) ((x).pgd[0])
38#define pgprot_val(x) ((x).pgprot)
39
40#define __pte(x) ((pte_t) { (x) } )
41#define __pmd(x) ((pmd_t) { (x) } )
42#define __pgprot(x) ((pgprot_t) { (x) } )
43
44#else
45/*
46 * .. while these make it easier on the compiler
47 */
48typedef pteval_t pte_t;
49typedef unsigned long pmd_t;
50typedef unsigned long pgd_t[2];
51typedef unsigned long pgprot_t;
52
53#define pte_val(x) (x)
54#define pmd_val(x) (x)
55#define pgd_val(x) ((x)[0])
56#define pgprot_val(x) (x)
57
58#define __pte(x) (x)
59#define __pmd(x) (x)
60#define __pgprot(x) (x)
61
62#endif /* STRICT_MM_TYPECHECKS */
63
64#endif /* _ASM_PGTABLE_2LEVEL_TYPES_H */
diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h
new file mode 100644
index 000000000000..470457e1cfc5
--- /dev/null
+++ b/arch/arm/include/asm/pgtable-2level.h
@@ -0,0 +1,143 @@
1/*
2 * arch/arm/include/asm/pgtable-2level.h
3 *
4 * Copyright (C) 1995-2002 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#ifndef _ASM_PGTABLE_2LEVEL_H
11#define _ASM_PGTABLE_2LEVEL_H
12
13/*
14 * Hardware-wise, we have a two level page table structure, where the first
15 * level has 4096 entries, and the second level has 256 entries. Each entry
16 * is one 32-bit word. Most of the bits in the second level entry are used
17 * by hardware, and there aren't any "accessed" and "dirty" bits.
18 *
19 * Linux on the other hand has a three level page table structure, which can
20 * be wrapped to fit a two level page table structure easily - using the PGD
21 * and PTE only. However, Linux also expects one "PTE" table per page, and
22 * at least a "dirty" bit.
23 *
24 * Therefore, we tweak the implementation slightly - we tell Linux that we
25 * have 2048 entries in the first level, each of which is 8 bytes (iow, two
26 * hardware pointers to the second level.) The second level contains two
27 * hardware PTE tables arranged contiguously, preceded by Linux versions
28 * which contain the state information Linux needs. We, therefore, end up
29 * with 512 entries in the "PTE" level.
30 *
31 * This leads to the page tables having the following layout:
32 *
33 * pgd pte
34 * | |
35 * +--------+
36 * | | +------------+ +0
37 * +- - - - + | Linux pt 0 |
38 * | | +------------+ +1024
39 * +--------+ +0 | Linux pt 1 |
40 * | |-----> +------------+ +2048
41 * +- - - - + +4 | h/w pt 0 |
42 * | |-----> +------------+ +3072
43 * +--------+ +8 | h/w pt 1 |
44 * | | +------------+ +4096
45 *
46 * See L_PTE_xxx below for definitions of bits in the "Linux pt", and
47 * PTE_xxx for definitions of bits appearing in the "h/w pt".
48 *
49 * PMD_xxx definitions refer to bits in the first level page table.
50 *
51 * The "dirty" bit is emulated by only granting hardware write permission
52 * iff the page is marked "writable" and "dirty" in the Linux PTE. This
53 * means that a write to a clean page will cause a permission fault, and
54 * the Linux MM layer will mark the page dirty via handle_pte_fault().
55 * For the hardware to notice the permission change, the TLB entry must
56 * be flushed, and ptep_set_access_flags() does that for us.
57 *
58 * The "accessed" or "young" bit is emulated by a similar method; we only
59 * allow accesses to the page if the "young" bit is set. Accesses to the
60 * page will cause a fault, and handle_pte_fault() will set the young bit
61 * for us as long as the page is marked present in the corresponding Linux
62 * PTE entry. Again, ptep_set_access_flags() will ensure that the TLB is
63 * up to date.
64 *
65 * However, when the "young" bit is cleared, we deny access to the page
66 * by clearing the hardware PTE. Currently Linux does not flush the TLB
67 * for us in this case, which means the TLB will retain the transation
68 * until either the TLB entry is evicted under pressure, or a context
69 * switch which changes the user space mapping occurs.
70 */
71#define PTRS_PER_PTE 512
72#define PTRS_PER_PMD 1
73#define PTRS_PER_PGD 2048
74
75#define PTE_HWTABLE_PTRS (PTRS_PER_PTE)
76#define PTE_HWTABLE_OFF (PTE_HWTABLE_PTRS * sizeof(pte_t))
77#define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u32))
78
79/*
80 * PMD_SHIFT determines the size of the area a second-level page table can map
81 * PGDIR_SHIFT determines what a third-level page table entry can map
82 */
83#define PMD_SHIFT 21
84#define PGDIR_SHIFT 21
85
86#define PMD_SIZE (1UL << PMD_SHIFT)
87#define PMD_MASK (~(PMD_SIZE-1))
88#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
89#define PGDIR_MASK (~(PGDIR_SIZE-1))
90
91/*
92 * section address mask and size definitions.
93 */
94#define SECTION_SHIFT 20
95#define SECTION_SIZE (1UL << SECTION_SHIFT)
96#define SECTION_MASK (~(SECTION_SIZE-1))
97
98/*
99 * ARMv6 supersection address mask and size definitions.
100 */
101#define SUPERSECTION_SHIFT 24
102#define SUPERSECTION_SIZE (1UL << SUPERSECTION_SHIFT)
103#define SUPERSECTION_MASK (~(SUPERSECTION_SIZE-1))
104
105#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
106
107/*
108 * "Linux" PTE definitions.
109 *
110 * We keep two sets of PTEs - the hardware and the linux version.
111 * This allows greater flexibility in the way we map the Linux bits
112 * onto the hardware tables, and allows us to have YOUNG and DIRTY
113 * bits.
114 *
115 * The PTE table pointer refers to the hardware entries; the "Linux"
116 * entries are stored 1024 bytes below.
117 */
118#define L_PTE_PRESENT (_AT(pteval_t, 1) << 0)
119#define L_PTE_YOUNG (_AT(pteval_t, 1) << 1)
120#define L_PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !PRESENT */
121#define L_PTE_DIRTY (_AT(pteval_t, 1) << 6)
122#define L_PTE_RDONLY (_AT(pteval_t, 1) << 7)
123#define L_PTE_USER (_AT(pteval_t, 1) << 8)
124#define L_PTE_XN (_AT(pteval_t, 1) << 9)
125#define L_PTE_SHARED (_AT(pteval_t, 1) << 10) /* shared(v6), coherent(xsc3) */
126
127/*
128 * These are the memory types, defined to be compatible with
129 * pre-ARMv6 CPUs cacheable and bufferable bits: XXCB
130 */
131#define L_PTE_MT_UNCACHED (_AT(pteval_t, 0x00) << 2) /* 0000 */
132#define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */
133#define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 0x02) << 2) /* 0010 */
134#define L_PTE_MT_WRITEBACK (_AT(pteval_t, 0x03) << 2) /* 0011 */
135#define L_PTE_MT_MINICACHE (_AT(pteval_t, 0x06) << 2) /* 0110 (sa1100, xscale) */
136#define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 0x07) << 2) /* 0111 */
137#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */
138#define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */
139#define L_PTE_MT_DEV_WC (_AT(pteval_t, 0x09) << 2) /* 1001 */
140#define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 0x0b) << 2) /* 1011 */
141#define L_PTE_MT_MASK (_AT(pteval_t, 0x0f) << 2)
142
143#endif /* _ASM_PGTABLE_2LEVEL_H */
diff --git a/arch/arm/include/asm/pgtable-hwdef.h b/arch/arm/include/asm/pgtable-hwdef.h
index fd1521d5cb9d..183111164ce9 100644
--- a/arch/arm/include/asm/pgtable-hwdef.h
+++ b/arch/arm/include/asm/pgtable-hwdef.h
@@ -10,81 +10,6 @@
10#ifndef _ASMARM_PGTABLE_HWDEF_H 10#ifndef _ASMARM_PGTABLE_HWDEF_H
11#define _ASMARM_PGTABLE_HWDEF_H 11#define _ASMARM_PGTABLE_HWDEF_H
12 12
13/* 13#include <asm/pgtable-2level-hwdef.h>
14 * Hardware page table definitions.
15 *
16 * + Level 1 descriptor (PMD)
17 * - common
18 */
19#define PMD_TYPE_MASK (3 << 0)
20#define PMD_TYPE_FAULT (0 << 0)
21#define PMD_TYPE_TABLE (1 << 0)
22#define PMD_TYPE_SECT (2 << 0)
23#define PMD_BIT4 (1 << 4)
24#define PMD_DOMAIN(x) ((x) << 5)
25#define PMD_PROTECTION (1 << 9) /* v5 */
26/*
27 * - section
28 */
29#define PMD_SECT_BUFFERABLE (1 << 2)
30#define PMD_SECT_CACHEABLE (1 << 3)
31#define PMD_SECT_XN (1 << 4) /* v6 */
32#define PMD_SECT_AP_WRITE (1 << 10)
33#define PMD_SECT_AP_READ (1 << 11)
34#define PMD_SECT_TEX(x) ((x) << 12) /* v5 */
35#define PMD_SECT_APX (1 << 15) /* v6 */
36#define PMD_SECT_S (1 << 16) /* v6 */
37#define PMD_SECT_nG (1 << 17) /* v6 */
38#define PMD_SECT_SUPER (1 << 18) /* v6 */
39
40#define PMD_SECT_UNCACHED (0)
41#define PMD_SECT_BUFFERED (PMD_SECT_BUFFERABLE)
42#define PMD_SECT_WT (PMD_SECT_CACHEABLE)
43#define PMD_SECT_WB (PMD_SECT_CACHEABLE | PMD_SECT_BUFFERABLE)
44#define PMD_SECT_MINICACHE (PMD_SECT_TEX(1) | PMD_SECT_CACHEABLE)
45#define PMD_SECT_WBWA (PMD_SECT_TEX(1) | PMD_SECT_CACHEABLE | PMD_SECT_BUFFERABLE)
46#define PMD_SECT_NONSHARED_DEV (PMD_SECT_TEX(2))
47
48/*
49 * - coarse table (not used)
50 */
51
52/*
53 * + Level 2 descriptor (PTE)
54 * - common
55 */
56#define PTE_TYPE_MASK (3 << 0)
57#define PTE_TYPE_FAULT (0 << 0)
58#define PTE_TYPE_LARGE (1 << 0)
59#define PTE_TYPE_SMALL (2 << 0)
60#define PTE_TYPE_EXT (3 << 0) /* v5 */
61#define PTE_BUFFERABLE (1 << 2)
62#define PTE_CACHEABLE (1 << 3)
63
64/*
65 * - extended small page/tiny page
66 */
67#define PTE_EXT_XN (1 << 0) /* v6 */
68#define PTE_EXT_AP_MASK (3 << 4)
69#define PTE_EXT_AP0 (1 << 4)
70#define PTE_EXT_AP1 (2 << 4)
71#define PTE_EXT_AP_UNO_SRO (0 << 4)
72#define PTE_EXT_AP_UNO_SRW (PTE_EXT_AP0)
73#define PTE_EXT_AP_URO_SRW (PTE_EXT_AP1)
74#define PTE_EXT_AP_URW_SRW (PTE_EXT_AP1|PTE_EXT_AP0)
75#define PTE_EXT_TEX(x) ((x) << 6) /* v5 */
76#define PTE_EXT_APX (1 << 9) /* v6 */
77#define PTE_EXT_COHERENT (1 << 9) /* XScale3 */
78#define PTE_EXT_SHARED (1 << 10) /* v6 */
79#define PTE_EXT_NG (1 << 11) /* v6 */
80
81/*
82 * - small page
83 */
84#define PTE_SMALL_AP_MASK (0xff << 4)
85#define PTE_SMALL_AP_UNO_SRO (0x00 << 4)
86#define PTE_SMALL_AP_UNO_SRW (0x55 << 4)
87#define PTE_SMALL_AP_URO_SRW (0xaa << 4)
88#define PTE_SMALL_AP_URW_SRW (0xff << 4)
89 14
90#endif 15#endif
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 5750704e0271..d6436dacb17b 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -24,6 +24,8 @@
24#include <mach/vmalloc.h> 24#include <mach/vmalloc.h>
25#include <asm/pgtable-hwdef.h> 25#include <asm/pgtable-hwdef.h>
26 26
27#include <asm/pgtable-2level.h>
28
27/* 29/*
28 * Just any arbitrary offset to the start of the vmalloc VM area: the 30 * Just any arbitrary offset to the start of the vmalloc VM area: the
29 * current 8MB value just means that there will be a 8MB "hole" after the 31 * current 8MB value just means that there will be a 8MB "hole" after the
@@ -41,79 +43,6 @@
41#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) 43#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
42#endif 44#endif
43 45
44/*
45 * Hardware-wise, we have a two level page table structure, where the first
46 * level has 4096 entries, and the second level has 256 entries. Each entry
47 * is one 32-bit word. Most of the bits in the second level entry are used
48 * by hardware, and there aren't any "accessed" and "dirty" bits.
49 *
50 * Linux on the other hand has a three level page table structure, which can
51 * be wrapped to fit a two level page table structure easily - using the PGD
52 * and PTE only. However, Linux also expects one "PTE" table per page, and
53 * at least a "dirty" bit.
54 *
55 * Therefore, we tweak the implementation slightly - we tell Linux that we
56 * have 2048 entries in the first level, each of which is 8 bytes (iow, two
57 * hardware pointers to the second level.) The second level contains two
58 * hardware PTE tables arranged contiguously, preceded by Linux versions
59 * which contain the state information Linux needs. We, therefore, end up
60 * with 512 entries in the "PTE" level.
61 *
62 * This leads to the page tables having the following layout:
63 *
64 * pgd pte
65 * | |
66 * +--------+
67 * | | +------------+ +0
68 * +- - - - + | Linux pt 0 |
69 * | | +------------+ +1024
70 * +--------+ +0 | Linux pt 1 |
71 * | |-----> +------------+ +2048
72 * +- - - - + +4 | h/w pt 0 |
73 * | |-----> +------------+ +3072
74 * +--------+ +8 | h/w pt 1 |
75 * | | +------------+ +4096
76 *
77 * See L_PTE_xxx below for definitions of bits in the "Linux pt", and
78 * PTE_xxx for definitions of bits appearing in the "h/w pt".
79 *
80 * PMD_xxx definitions refer to bits in the first level page table.
81 *
82 * The "dirty" bit is emulated by only granting hardware write permission
83 * iff the page is marked "writable" and "dirty" in the Linux PTE. This
84 * means that a write to a clean page will cause a permission fault, and
85 * the Linux MM layer will mark the page dirty via handle_pte_fault().
86 * For the hardware to notice the permission change, the TLB entry must
87 * be flushed, and ptep_set_access_flags() does that for us.
88 *
89 * The "accessed" or "young" bit is emulated by a similar method; we only
90 * allow accesses to the page if the "young" bit is set. Accesses to the
91 * page will cause a fault, and handle_pte_fault() will set the young bit
92 * for us as long as the page is marked present in the corresponding Linux
93 * PTE entry. Again, ptep_set_access_flags() will ensure that the TLB is
94 * up to date.
95 *
96 * However, when the "young" bit is cleared, we deny access to the page
97 * by clearing the hardware PTE. Currently Linux does not flush the TLB
98 * for us in this case, which means the TLB will retain the transation
99 * until either the TLB entry is evicted under pressure, or a context
100 * switch which changes the user space mapping occurs.
101 */
102#define PTRS_PER_PTE 512
103#define PTRS_PER_PMD 1
104#define PTRS_PER_PGD 2048
105
106#define PTE_HWTABLE_PTRS (PTRS_PER_PTE)
107#define PTE_HWTABLE_OFF (PTE_HWTABLE_PTRS * sizeof(pte_t))
108#define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u32))
109
110/*
111 * PMD_SHIFT determines the size of the area a second-level page table can map
112 * PGDIR_SHIFT determines what a third-level page table entry can map
113 */
114#define PMD_SHIFT 21
115#define PGDIR_SHIFT 21
116
117#define LIBRARY_TEXT_START 0x0c000000 46#define LIBRARY_TEXT_START 0x0c000000
118 47
119#ifndef __ASSEMBLY__ 48#ifndef __ASSEMBLY__
@@ -124,12 +53,6 @@ extern void __pgd_error(const char *file, int line, pgd_t);
124#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte) 53#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte)
125#define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd) 54#define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd)
126#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd) 55#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd)
127#endif /* !__ASSEMBLY__ */
128
129#define PMD_SIZE (1UL << PMD_SHIFT)
130#define PMD_MASK (~(PMD_SIZE-1))
131#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
132#define PGDIR_MASK (~(PGDIR_SIZE-1))
133 56
134/* 57/*
135 * This is the lowest virtual address we can permit any user space 58 * This is the lowest virtual address we can permit any user space
@@ -138,60 +61,6 @@ extern void __pgd_error(const char *file, int line, pgd_t);
138 */ 61 */
139#define FIRST_USER_ADDRESS PAGE_SIZE 62#define FIRST_USER_ADDRESS PAGE_SIZE
140 63
141#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
142
143/*
144 * section address mask and size definitions.
145 */
146#define SECTION_SHIFT 20
147#define SECTION_SIZE (1UL << SECTION_SHIFT)
148#define SECTION_MASK (~(SECTION_SIZE-1))
149
150/*
151 * ARMv6 supersection address mask and size definitions.
152 */
153#define SUPERSECTION_SHIFT 24
154#define SUPERSECTION_SIZE (1UL << SUPERSECTION_SHIFT)
155#define SUPERSECTION_MASK (~(SUPERSECTION_SIZE-1))
156
157/*
158 * "Linux" PTE definitions.
159 *
160 * We keep two sets of PTEs - the hardware and the linux version.
161 * This allows greater flexibility in the way we map the Linux bits
162 * onto the hardware tables, and allows us to have YOUNG and DIRTY
163 * bits.
164 *
165 * The PTE table pointer refers to the hardware entries; the "Linux"
166 * entries are stored 1024 bytes below.
167 */
168#define L_PTE_PRESENT (_AT(pteval_t, 1) << 0)
169#define L_PTE_YOUNG (_AT(pteval_t, 1) << 1)
170#define L_PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !PRESENT */
171#define L_PTE_DIRTY (_AT(pteval_t, 1) << 6)
172#define L_PTE_RDONLY (_AT(pteval_t, 1) << 7)
173#define L_PTE_USER (_AT(pteval_t, 1) << 8)
174#define L_PTE_XN (_AT(pteval_t, 1) << 9)
175#define L_PTE_SHARED (_AT(pteval_t, 1) << 10) /* shared(v6), coherent(xsc3) */
176
177/*
178 * These are the memory types, defined to be compatible with
179 * pre-ARMv6 CPUs cacheable and bufferable bits: XXCB
180 */
181#define L_PTE_MT_UNCACHED (_AT(pteval_t, 0x00) << 2) /* 0000 */
182#define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */
183#define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 0x02) << 2) /* 0010 */
184#define L_PTE_MT_WRITEBACK (_AT(pteval_t, 0x03) << 2) /* 0011 */
185#define L_PTE_MT_MINICACHE (_AT(pteval_t, 0x06) << 2) /* 0110 (sa1100, xscale) */
186#define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 0x07) << 2) /* 0111 */
187#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */
188#define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */
189#define L_PTE_MT_DEV_WC (_AT(pteval_t, 0x09) << 2) /* 1001 */
190#define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 0x0b) << 2) /* 1011 */
191#define L_PTE_MT_MASK (_AT(pteval_t, 0x0f) << 2)
192
193#ifndef __ASSEMBLY__
194
195/* 64/*
196 * The pgprot_* and protection_map entries will be fixed up in runtime 65 * The pgprot_* and protection_map entries will be fixed up in runtime
197 * to include the cachable and bufferable bits based on memory policy, 66 * to include the cachable and bufferable bits based on memory policy,