1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
7 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
8 */
9#ifndef _ASM_PGTABLE_32_H
10#define _ASM_PGTABLE_32_H
11
12#include <asm/addrspace.h>
13#include <asm/page.h>
14
15#include <linux/linkage.h>
16#include <asm/cachectl.h>
17#include <asm/fixmap.h>
18
19#include <asm-generic/pgtable-nopmd.h>
20
21extern int temp_tlb_entry __cpuinitdata;
22
23/*
24 * - add_temporary_entry() add a temporary TLB entry. We use TLB entries
25 *	starting at the top and working down. This is for populating the
26 *	TLB before trap_init() puts the TLB miss handler in place. It
27 *	should be used only for entries matching the actual page tables,
28 *	to prevent inconsistencies.
29 */
30extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
31			       unsigned long entryhi, unsigned long pagemask);
32
33/*
34 * Basically we have the same two-level (which is the logical three level
35 * Linux page table layout folded) page tables as the i386.  Some day
36 * when we have proper page coloring support we can have a 1% quicker
37 * tlb refill handling mechanism, but for now it is a bit slower but
38 * works even with the cache aliasing problem the R4k and above have.
39 */
40
41/* PGDIR_SHIFT determines what a third-level page table entry can map */
42#define PGDIR_SHIFT	(2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2)
43#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
44#define PGDIR_MASK	(~(PGDIR_SIZE-1))
45
46/*
47 * Entries per page directory level: we use two-level, so
48 * we don't really have any PUD/PMD directory physically.
49 */
50#define __PGD_ORDER	(32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
51#define PGD_ORDER	(__PGD_ORDER >= 0 ? __PGD_ORDER : 0)
52#define PUD_ORDER	aieeee_attempt_to_allocate_pud
53#define PMD_ORDER	1
54#define PTE_ORDER	0
55
56#define PTRS_PER_PGD	(USER_PTRS_PER_PGD * 2)
57#define PTRS_PER_PTE	((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
58
59#define USER_PTRS_PER_PGD	(0x80000000UL/PGDIR_SIZE)
60#define FIRST_USER_ADDRESS	0UL
61
62#define VMALLOC_START	  MAP_BASE
63
64#define PKMAP_BASE		(0xfe000000UL)
65
66#ifdef CONFIG_HIGHMEM
67# define VMALLOC_END	(PKMAP_BASE-2*PAGE_SIZE)
68#else
69# define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
70#endif
71
72#ifdef CONFIG_PHYS_ADDR_T_64BIT
73#define pte_ERROR(e) \
74	printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
75#else
76#define pte_ERROR(e) \
77	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
78#endif
79#define pgd_ERROR(e) \
80	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
81
82extern void load_pgd(unsigned long pg_dir);
83
84extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
85
86/*
87 * Empty pgd/pmd entries point to the invalid_pte_table.
88 */
89static inline int pmd_none(pmd_t pmd)
90{
91	return pmd_val(pmd) == (unsigned long) invalid_pte_table;
92}
93
94#define pmd_bad(pmd)		(pmd_val(pmd) & ~PAGE_MASK)
95
96static inline int pmd_present(pmd_t pmd)
97{
98	return pmd_val(pmd) != (unsigned long) invalid_pte_table;
99}
100
101static inline void pmd_clear(pmd_t *pmdp)
102{
103	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
104}
105
106#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
107#define pte_page(x)		pfn_to_page(pte_pfn(x))
108#define pte_pfn(x)		(((unsigned long)((x).pte_high >> _PFN_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT))
109static inline pte_t
110pfn_pte(unsigned long pfn, pgprot_t prot)
111{
112	pte_t pte;
113
114	pte.pte_low = (pfn >> _PAGE_PRESENT_SHIFT) |
115				(pgprot_val(prot) & ~_PFNX_MASK);
116	pte.pte_high = (pfn << _PFN_SHIFT) |
117				(pgprot_val(prot) & ~_PFN_MASK);
118	return pte;
119}
120
121#else
122
123#define pte_page(x)		pfn_to_page(pte_pfn(x))
124
125#ifdef CONFIG_CPU_VR41XX
126#define pte_pfn(x)		((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
127#define pfn_pte(pfn, prot)	__pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
128#else
129#define pte_pfn(x)		((unsigned long)((x).pte >> _PFN_SHIFT))
130#define pfn_pte(pfn, prot)	__pte(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
131#endif
132#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
133
134#define __pgd_offset(address)	pgd_index(address)
135#define __pud_offset(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
136#define __pmd_offset(address)	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
137
138/* to find an entry in a kernel page-table-directory */
139#define pgd_offset_k(address) pgd_offset(&init_mm, address)
140
141#define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
142
143/* to find an entry in a page-table-directory */
144#define pgd_offset(mm, addr)	((mm)->pgd + pgd_index(addr))
145
146/* Find an entry in the third-level page table.. */
147#define __pte_offset(address)						\
148	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
149#define pte_offset(dir, address)					\
150	((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
151#define pte_offset_kernel(dir, address)					\
152	((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
153
154#define pte_offset_map(dir, address)					\
155	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
156#define pte_unmap(pte) ((void)(pte))
157
158#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
159
160/* Swap entries must have VALID bit cleared. */
161#define __swp_type(x)			(((x).val >> 10) & 0x1f)
162#define __swp_offset(x)			((x).val >> 15)
163#define __swp_entry(type,offset)	((swp_entry_t) { ((type) << 10) | ((offset) << 15) })
164#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
165#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
166
167#else
168
169#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
170
171/* Swap entries must have VALID and GLOBAL bits cleared. */
172#define __swp_type(x)			(((x).val >> 4) & 0x1f)
173#define __swp_offset(x)			 ((x).val >> 9)
174#define __swp_entry(type,offset)	((swp_entry_t)  { ((type) << 4) | ((offset) << 9) })
175#define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_high })
176#define __swp_entry_to_pte(x)		((pte_t) { 0, (x).val })
177
178#else
179/*
180 * Constraints:
181 *      _PAGE_PRESENT at bit 0
182 *      _PAGE_MODIFIED at bit 4
183 *      _PAGE_GLOBAL at bit 6
184 *      _PAGE_VALID at bit 7
185 */
186#define __swp_type(x)			(((x).val >> 8) & 0x1f)
187#define __swp_offset(x)			 ((x).val >> 13)
188#define __swp_entry(type,offset)	((swp_entry_t)	{ ((type) << 8) | ((offset) << 13) })
189#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
190#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
191
192#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
193
194#endif /* defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) */
195
196#endif /* _ASM_PGTABLE_32_H */
197