Linux kernel mirror (for testing)
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linux
1/*
2 * linux/arch/unicore32/include/asm/pgtable.h
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#ifndef __UNICORE_PGTABLE_H__
13#define __UNICORE_PGTABLE_H__
14
15#define __ARCH_USE_5LEVEL_HACK
16#include <asm-generic/pgtable-nopmd.h>
17#include <asm/cpu-single.h>
18
19#include <asm/memory.h>
20#include <asm/pgtable-hwdef.h>
21
22/*
23 * Just any arbitrary offset to the start of the vmalloc VM area: the
24 * current 8MB value just means that there will be a 8MB "hole" after the
25 * physical memory until the kernel virtual memory starts. That means that
26 * any out-of-bounds memory accesses will hopefully be caught.
27 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
28 * area for the same reason. ;)
29 *
30 * Note that platforms may override VMALLOC_START, but they must provide
31 * VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space,
32 * which may not overlap IO space.
33 */
34#ifndef VMALLOC_START
35#define VMALLOC_OFFSET SZ_8M
36#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) \
37 & ~(VMALLOC_OFFSET-1))
38#define VMALLOC_END (0xff000000UL)
39#endif
40
41#define PTRS_PER_PTE 1024
42#define PTRS_PER_PGD 1024
43
44/*
45 * PGDIR_SHIFT determines what a third-level page table entry can map
46 */
47#define PGDIR_SHIFT 22
48
49#ifndef __ASSEMBLY__
50extern void __pte_error(const char *file, int line, unsigned long val);
51extern void __pgd_error(const char *file, int line, unsigned long val);
52
53#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte_val(pte))
54#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
55#endif /* !__ASSEMBLY__ */
56
57#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
58#define PGDIR_MASK (~(PGDIR_SIZE-1))
59
60/*
61 * This is the lowest virtual address we can permit any user space
62 * mapping to be mapped at. This is particularly important for
63 * non-high vector CPUs.
64 */
65#define FIRST_USER_ADDRESS PAGE_SIZE
66
67#define FIRST_USER_PGD_NR 1
68#define USER_PTRS_PER_PGD ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)
69
70/*
71 * section address mask and size definitions.
72 */
73#define SECTION_SHIFT 22
74#define SECTION_SIZE (1UL << SECTION_SHIFT)
75#define SECTION_MASK (~(SECTION_SIZE-1))
76
77#ifndef __ASSEMBLY__
78
79/*
80 * The pgprot_* and protection_map entries will be fixed up in runtime
81 * to include the cachable bits based on memory policy, as well as any
82 * architecture dependent bits.
83 */
84#define _PTE_DEFAULT (PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE)
85
86extern pgprot_t pgprot_user;
87extern pgprot_t pgprot_kernel;
88
89#define PAGE_NONE pgprot_user
90#define PAGE_SHARED __pgprot(pgprot_val(pgprot_user | PTE_READ \
91 | PTE_WRITE))
92#define PAGE_SHARED_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \
93 | PTE_WRITE \
94 | PTE_EXEC))
95#define PAGE_COPY __pgprot(pgprot_val(pgprot_user | PTE_READ)
96#define PAGE_COPY_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \
97 | PTE_EXEC))
98#define PAGE_READONLY __pgprot(pgprot_val(pgprot_user | PTE_READ))
99#define PAGE_READONLY_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \
100 | PTE_EXEC))
101#define PAGE_KERNEL pgprot_kernel
102#define PAGE_KERNEL_EXEC __pgprot(pgprot_val(pgprot_kernel | PTE_EXEC))
103
104#define __PAGE_NONE __pgprot(_PTE_DEFAULT)
105#define __PAGE_SHARED __pgprot(_PTE_DEFAULT | PTE_READ \
106 | PTE_WRITE)
107#define __PAGE_SHARED_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \
108 | PTE_WRITE \
109 | PTE_EXEC)
110#define __PAGE_COPY __pgprot(_PTE_DEFAULT | PTE_READ)
111#define __PAGE_COPY_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \
112 | PTE_EXEC)
113#define __PAGE_READONLY __pgprot(_PTE_DEFAULT | PTE_READ)
114#define __PAGE_READONLY_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \
115 | PTE_EXEC)
116
117#endif /* __ASSEMBLY__ */
118
119/*
120 * The table below defines the page protection levels that we insert into our
121 * Linux page table version. These get translated into the best that the
122 * architecture can perform. Note that on UniCore hardware:
123 * 1) We cannot do execute protection
124 * 2) If we could do execute protection, then read is implied
125 * 3) write implies read permissions
126 */
127#define __P000 __PAGE_NONE
128#define __P001 __PAGE_READONLY
129#define __P010 __PAGE_COPY
130#define __P011 __PAGE_COPY
131#define __P100 __PAGE_READONLY_EXEC
132#define __P101 __PAGE_READONLY_EXEC
133#define __P110 __PAGE_COPY_EXEC
134#define __P111 __PAGE_COPY_EXEC
135
136#define __S000 __PAGE_NONE
137#define __S001 __PAGE_READONLY
138#define __S010 __PAGE_SHARED
139#define __S011 __PAGE_SHARED
140#define __S100 __PAGE_READONLY_EXEC
141#define __S101 __PAGE_READONLY_EXEC
142#define __S110 __PAGE_SHARED_EXEC
143#define __S111 __PAGE_SHARED_EXEC
144
145#ifndef __ASSEMBLY__
146/*
147 * ZERO_PAGE is a global shared page that is always zero: used
148 * for zero-mapped memory areas etc..
149 */
150extern struct page *empty_zero_page;
151#define ZERO_PAGE(vaddr) (empty_zero_page)
152
153#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
154#define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) \
155 | pgprot_val(prot)))
156
157#define pte_none(pte) (!pte_val(pte))
158#define pte_clear(mm, addr, ptep) set_pte(ptep, __pte(0))
159#define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
160#define pte_offset_kernel(dir, addr) (pmd_page_vaddr(*(dir)) \
161 + __pte_index(addr))
162
163#define pte_offset_map(dir, addr) (pmd_page_vaddr(*(dir)) \
164 + __pte_index(addr))
165#define pte_unmap(pte) do { } while (0)
166
167#define set_pte(ptep, pte) cpu_set_pte(ptep, pte)
168
169#define set_pte_at(mm, addr, ptep, pteval) \
170 do { \
171 set_pte(ptep, pteval); \
172 } while (0)
173
174/*
175 * The following only work if pte_present() is true.
176 * Undefined behaviour if not..
177 */
178#define pte_present(pte) (pte_val(pte) & PTE_PRESENT)
179#define pte_write(pte) (pte_val(pte) & PTE_WRITE)
180#define pte_dirty(pte) (pte_val(pte) & PTE_DIRTY)
181#define pte_young(pte) (pte_val(pte) & PTE_YOUNG)
182#define pte_exec(pte) (pte_val(pte) & PTE_EXEC)
183#define pte_special(pte) (0)
184
185#define PTE_BIT_FUNC(fn, op) \
186static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
187
188PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
189PTE_BIT_FUNC(mkwrite, |= PTE_WRITE);
190PTE_BIT_FUNC(mkclean, &= ~PTE_DIRTY);
191PTE_BIT_FUNC(mkdirty, |= PTE_DIRTY);
192PTE_BIT_FUNC(mkold, &= ~PTE_YOUNG);
193PTE_BIT_FUNC(mkyoung, |= PTE_YOUNG);
194
195static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
196
197/*
198 * Mark the prot value as uncacheable.
199 */
200#define pgprot_noncached(prot) \
201 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
202#define pgprot_writecombine(prot) \
203 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
204#define pgprot_dmacoherent(prot) \
205 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
206
207#define pmd_none(pmd) (!pmd_val(pmd))
208#define pmd_present(pmd) (pmd_val(pmd) & PMD_PRESENT)
209#define pmd_bad(pmd) (((pmd_val(pmd) & \
210 (PMD_PRESENT | PMD_TYPE_MASK)) \
211 != (PMD_PRESENT | PMD_TYPE_TABLE)))
212
213#define set_pmd(pmdpd, pmdval) \
214 do { \
215 *(pmdpd) = pmdval; \
216 } while (0)
217
218#define pmd_clear(pmdp) \
219 do { \
220 set_pmd(pmdp, __pmd(0));\
221 clean_pmd_entry(pmdp); \
222 } while (0)
223
224#define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK))
225#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd)))
226
227/*
228 * Conversion functions: convert a page and protection to a page entry,
229 * and a page entry and page directory to the page they refer to.
230 */
231#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)
232
233/* to find an entry in a page-table-directory */
234#define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
235
236#define pgd_offset(mm, addr) ((mm)->pgd+pgd_index(addr))
237
238/* to find an entry in a kernel page-table-directory */
239#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
240
241/* Find an entry in the third-level page table.. */
242#define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
243
244static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
245{
246 const unsigned long mask = PTE_EXEC | PTE_WRITE | PTE_READ;
247 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
248 return pte;
249}
250
251extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
252
253/*
254 * Encode and decode a swap entry. Swap entries are stored in the Linux
255 * page tables as follows:
256 *
257 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
258 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
259 * <--------------- offset --------------> <--- type --> 0 0 0 0 0
260 *
261 * This gives us up to 127 swap files and 32GB per swap file. Note that
262 * the offset field is always non-zero.
263 */
264#define __SWP_TYPE_SHIFT 5
265#define __SWP_TYPE_BITS 7
266#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
267#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
268
269#define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) \
270 & __SWP_TYPE_MASK)
271#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
272#define __swp_entry(type, offset) ((swp_entry_t) { \
273 ((type) << __SWP_TYPE_SHIFT) | \
274 ((offset) << __SWP_OFFSET_SHIFT) })
275
276#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
277#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
278
279/*
280 * It is an error for the kernel to have more swap files than we can
281 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES
282 * is increased beyond what we presently support.
283 */
284#define MAX_SWAPFILES_CHECK() \
285 BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
286
287/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
288/* FIXME: this is not correct */
289#define kern_addr_valid(addr) (1)
290
291#include <asm-generic/pgtable.h>
292
293#define pgtable_cache_init() do { } while (0)
294
295#endif /* !__ASSEMBLY__ */
296
297#endif /* __UNICORE_PGTABLE_H__ */