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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#define __ARCH_USE_5LEVEL_HACK
20#include <asm-generic/pgtable-nopmd.h>
21
22#ifdef CONFIG_HIGHMEM
23#include <asm/highmem.h>
24#endif
25
26/*
27 * Regarding 32-bit MIPS huge page support (and the tradeoff it entails):
28 *
29 * We use the same huge page sizes as 64-bit MIPS. Assuming a 4KB page size,
30 * our 2-level table layout would normally have a PGD entry cover a contiguous
31 * 4MB virtual address region (pointing to a 4KB PTE page of 1,024 32-bit pte_t
32 * pointers, each pointing to a 4KB physical page). The problem is that 4MB,
33 * spanning both halves of a TLB EntryLo0,1 pair, requires 2MB hardware page
34 * support, not one of the standard supported sizes (1MB,4MB,16MB,...).
35 * To correct for this, when huge pages are enabled, we halve the number of
36 * pointers a PTE page holds, making its last half go to waste. Correspondingly,
37 * we double the number of PGD pages. Overall, page table memory overhead
38 * increases to match 64-bit MIPS, but PTE lookups remain CPU cache-friendly.
39 *
40 * NOTE: We don't yet support huge pages if extended-addressing is enabled
41 * (i.e. EVA, XPA, 36-bit Alchemy/Netlogic).
42 */
43
44extern int temp_tlb_entry;
45
46/*
47 * - add_temporary_entry() add a temporary TLB entry. We use TLB entries
48 * starting at the top and working down. This is for populating the
49 * TLB before trap_init() puts the TLB miss handler in place. It
50 * should be used only for entries matching the actual page tables,
51 * to prevent inconsistencies.
52 */
53extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
54 unsigned long entryhi, unsigned long pagemask);
55
56/*
57 * Basically we have the same two-level (which is the logical three level
58 * Linux page table layout folded) page tables as the i386. Some day
59 * when we have proper page coloring support we can have a 1% quicker
60 * tlb refill handling mechanism, but for now it is a bit slower but
61 * works even with the cache aliasing problem the R4k and above have.
62 */
63
64/* PGDIR_SHIFT determines what a third-level page table entry can map */
65#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
66# define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2 - 1)
67#else
68# define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2)
69#endif
70
71#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
72#define PGDIR_MASK (~(PGDIR_SIZE-1))
73
74/*
75 * Entries per page directory level: we use two-level, so
76 * we don't really have any PUD/PMD directory physically.
77 */
78#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
79# define __PGD_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2 + 1)
80#else
81# define __PGD_ORDER (32 - 3 * PAGE_SHIFT + PGD_T_LOG2 + PTE_T_LOG2)
82#endif
83
84#define PGD_ORDER (__PGD_ORDER >= 0 ? __PGD_ORDER : 0)
85#define PUD_ORDER aieeee_attempt_to_allocate_pud
86#define PMD_ORDER aieeee_attempt_to_allocate_pmd
87#define PTE_ORDER 0
88
89#define PTRS_PER_PGD (USER_PTRS_PER_PGD * 2)
90#if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) && !defined(CONFIG_PHYS_ADDR_T_64BIT)
91# define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t) / 2)
92#else
93# define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
94#endif
95
96#define USER_PTRS_PER_PGD (0x80000000UL/PGDIR_SIZE)
97#define FIRST_USER_ADDRESS 0UL
98
99#define VMALLOC_START MAP_BASE
100
101#define PKMAP_END ((FIXADDR_START) & ~((LAST_PKMAP << PAGE_SHIFT)-1))
102#define PKMAP_BASE (PKMAP_END - PAGE_SIZE * LAST_PKMAP)
103
104#ifdef CONFIG_HIGHMEM
105# define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE)
106#else
107# define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
108#endif
109
110#ifdef CONFIG_PHYS_ADDR_T_64BIT
111#define pte_ERROR(e) \
112 printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
113#else
114#define pte_ERROR(e) \
115 printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
116#endif
117#define pgd_ERROR(e) \
118 printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
119
120extern void load_pgd(unsigned long pg_dir);
121
122extern pte_t invalid_pte_table[PTRS_PER_PTE];
123
124/*
125 * Empty pgd/pmd entries point to the invalid_pte_table.
126 */
127static inline int pmd_none(pmd_t pmd)
128{
129 return pmd_val(pmd) == (unsigned long) invalid_pte_table;
130}
131
132static inline int pmd_bad(pmd_t pmd)
133{
134#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
135 /* pmd_huge(pmd) but inline */
136 if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
137 return 0;
138#endif
139
140 if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
141 return 1;
142
143 return 0;
144}
145
146static inline int pmd_present(pmd_t pmd)
147{
148 return pmd_val(pmd) != (unsigned long) invalid_pte_table;
149}
150
151static inline void pmd_clear(pmd_t *pmdp)
152{
153 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
154}
155
156#if defined(CONFIG_XPA)
157
158#define pte_pfn(x) (((unsigned long)((x).pte_high >> _PFN_SHIFT)) | (unsigned long)((x).pte_low << _PAGE_PRESENT_SHIFT))
159static inline pte_t
160pfn_pte(unsigned long pfn, pgprot_t prot)
161{
162 pte_t pte;
163
164 pte.pte_low = (pfn >> _PAGE_PRESENT_SHIFT) |
165 (pgprot_val(prot) & ~_PFNX_MASK);
166 pte.pte_high = (pfn << _PFN_SHIFT) |
167 (pgprot_val(prot) & ~_PFN_MASK);
168 return pte;
169}
170
171#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
172
173#define pte_pfn(x) ((unsigned long)((x).pte_high >> 6))
174
175static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
176{
177 pte_t pte;
178
179 pte.pte_high = (pfn << 6) | (pgprot_val(prot) & 0x3f);
180 pte.pte_low = pgprot_val(prot);
181
182 return pte;
183}
184
185#else
186
187#ifdef CONFIG_CPU_VR41XX
188#define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
189#define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
190#else
191#define pte_pfn(x) ((unsigned long)((x).pte >> _PFN_SHIFT))
192#define pfn_pte(pfn, prot) __pte(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
193#define pfn_pmd(pfn, prot) __pmd(((unsigned long long)(pfn) << _PFN_SHIFT) | pgprot_val(prot))
194#endif
195#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
196
197#define pte_page(x) pfn_to_page(pte_pfn(x))
198
199#define __pgd_offset(address) pgd_index(address)
200#define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
201#define __pmd_offset(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
202
203/* to find an entry in a kernel page-table-directory */
204#define pgd_offset_k(address) pgd_offset(&init_mm, address)
205
206#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
207#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
208
209/* to find an entry in a page-table-directory */
210#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
211
212/* Find an entry in the third-level page table.. */
213#define __pte_offset(address) \
214 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
215#define pte_offset(dir, address) \
216 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
217#define pte_offset_kernel(dir, address) \
218 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
219
220#define pte_offset_map(dir, address) \
221 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
222#define pte_unmap(pte) ((void)(pte))
223
224#if defined(CONFIG_CPU_R3K_TLB)
225
226/* Swap entries must have VALID bit cleared. */
227#define __swp_type(x) (((x).val >> 10) & 0x1f)
228#define __swp_offset(x) ((x).val >> 15)
229#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 10) | ((offset) << 15) })
230#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
231#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
232
233#else
234
235#if defined(CONFIG_XPA)
236
237/* Swap entries must have VALID and GLOBAL bits cleared. */
238#define __swp_type(x) (((x).val >> 4) & 0x1f)
239#define __swp_offset(x) ((x).val >> 9)
240#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 4) | ((offset) << 9) })
241#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
242#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })
243
244#elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
245
246/* Swap entries must have VALID and GLOBAL bits cleared. */
247#define __swp_type(x) (((x).val >> 2) & 0x1f)
248#define __swp_offset(x) ((x).val >> 7)
249#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 2) | ((offset) << 7) })
250#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
251#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })
252
253#else
254/*
255 * Constraints:
256 * _PAGE_PRESENT at bit 0
257 * _PAGE_MODIFIED at bit 4
258 * _PAGE_GLOBAL at bit 6
259 * _PAGE_VALID at bit 7
260 */
261#define __swp_type(x) (((x).val >> 8) & 0x1f)
262#define __swp_offset(x) ((x).val >> 13)
263#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 8) | ((offset) << 13) })
264#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
265#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
266
267#endif /* defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) */
268
269#endif /* defined(CONFIG_CPU_R3K_TLB) */
270
271#endif /* _ASM_PGTABLE_32_H */