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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#include <asm-generic/pgtable-nopmd.h>
16#include <asm/cpu-single.h>
17
18#include <asm/memory.h>
19#include <asm/pgtable-hwdef.h>
20
21/*
22 * Just any arbitrary offset to the start of the vmalloc VM area: the
23 * current 8MB value just means that there will be a 8MB "hole" after the
24 * physical memory until the kernel virtual memory starts. That means that
25 * any out-of-bounds memory accesses will hopefully be caught.
26 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
27 * area for the same reason. ;)
28 *
29 * Note that platforms may override VMALLOC_START, but they must provide
30 * VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space,
31 * which may not overlap IO space.
32 */
33#ifndef VMALLOC_START
34#define VMALLOC_OFFSET SZ_8M
35#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) \
36 & ~(VMALLOC_OFFSET-1))
37#define VMALLOC_END (0xff000000UL)
38#endif
39
40#define PTRS_PER_PTE 1024
41#define PTRS_PER_PGD 1024
42
43/*
44 * PGDIR_SHIFT determines what a third-level page table entry can map
45 */
46#define PGDIR_SHIFT 22
47
48#ifndef __ASSEMBLY__
49extern void __pte_error(const char *file, int line, unsigned long val);
50extern void __pgd_error(const char *file, int line, unsigned long val);
51
52#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte_val(pte))
53#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
54#endif /* !__ASSEMBLY__ */
55
56#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
57#define PGDIR_MASK (~(PGDIR_SIZE-1))
58
59/*
60 * This is the lowest virtual address we can permit any user space
61 * mapping to be mapped at. This is particularly important for
62 * non-high vector CPUs.
63 */
64#define FIRST_USER_ADDRESS PAGE_SIZE
65
66#define FIRST_USER_PGD_NR 1
67#define USER_PTRS_PER_PGD ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)
68
69/*
70 * section address mask and size definitions.
71 */
72#define SECTION_SHIFT 22
73#define SECTION_SIZE (1UL << SECTION_SHIFT)
74#define SECTION_MASK (~(SECTION_SIZE-1))
75
76#ifndef __ASSEMBLY__
77
78/*
79 * The pgprot_* and protection_map entries will be fixed up in runtime
80 * to include the cachable bits based on memory policy, as well as any
81 * architecture dependent bits.
82 */
83#define _PTE_DEFAULT (PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE)
84
85extern pgprot_t pgprot_user;
86extern pgprot_t pgprot_kernel;
87
88#define PAGE_NONE pgprot_user
89#define PAGE_SHARED __pgprot(pgprot_val(pgprot_user | PTE_READ \
90 | PTE_WRITE)
91#define PAGE_SHARED_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \
92 | PTE_WRITE \
93 | PTE_EXEC)
94#define PAGE_COPY __pgprot(pgprot_val(pgprot_user | PTE_READ)
95#define PAGE_COPY_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \
96 | PTE_EXEC)
97#define PAGE_READONLY __pgprot(pgprot_val(pgprot_user | PTE_READ)
98#define PAGE_READONLY_EXEC __pgprot(pgprot_val(pgprot_user | PTE_READ \
99 | PTE_EXEC)
100#define PAGE_KERNEL pgprot_kernel
101#define PAGE_KERNEL_EXEC __pgprot(pgprot_val(pgprot_kernel | PTE_EXEC))
102
103#define __PAGE_NONE __pgprot(_PTE_DEFAULT)
104#define __PAGE_SHARED __pgprot(_PTE_DEFAULT | PTE_READ \
105 | PTE_WRITE)
106#define __PAGE_SHARED_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \
107 | PTE_WRITE \
108 | PTE_EXEC)
109#define __PAGE_COPY __pgprot(_PTE_DEFAULT | PTE_READ)
110#define __PAGE_COPY_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \
111 | PTE_EXEC)
112#define __PAGE_READONLY __pgprot(_PTE_DEFAULT | PTE_READ)
113#define __PAGE_READONLY_EXEC __pgprot(_PTE_DEFAULT | PTE_READ \
114 | PTE_EXEC)
115
116#endif /* __ASSEMBLY__ */
117
118/*
119 * The table below defines the page protection levels that we insert into our
120 * Linux page table version. These get translated into the best that the
121 * architecture can perform. Note that on UniCore hardware:
122 * 1) We cannot do execute protection
123 * 2) If we could do execute protection, then read is implied
124 * 3) write implies read permissions
125 */
126#define __P000 __PAGE_NONE
127#define __P001 __PAGE_READONLY
128#define __P010 __PAGE_COPY
129#define __P011 __PAGE_COPY
130#define __P100 __PAGE_READONLY_EXEC
131#define __P101 __PAGE_READONLY_EXEC
132#define __P110 __PAGE_COPY_EXEC
133#define __P111 __PAGE_COPY_EXEC
134
135#define __S000 __PAGE_NONE
136#define __S001 __PAGE_READONLY
137#define __S010 __PAGE_SHARED
138#define __S011 __PAGE_SHARED
139#define __S100 __PAGE_READONLY_EXEC
140#define __S101 __PAGE_READONLY_EXEC
141#define __S110 __PAGE_SHARED_EXEC
142#define __S111 __PAGE_SHARED_EXEC
143
144#ifndef __ASSEMBLY__
145/*
146 * ZERO_PAGE is a global shared page that is always zero: used
147 * for zero-mapped memory areas etc..
148 */
149extern struct page *empty_zero_page;
150#define ZERO_PAGE(vaddr) (empty_zero_page)
151
152#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
153#define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) \
154 | pgprot_val(prot)))
155
156#define pte_none(pte) (!pte_val(pte))
157#define pte_clear(mm, addr, ptep) set_pte(ptep, __pte(0))
158#define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
159#define pte_offset_kernel(dir, addr) (pmd_page_vaddr(*(dir)) \
160 + __pte_index(addr))
161
162#define pte_offset_map(dir, addr) (pmd_page_vaddr(*(dir)) \
163 + __pte_index(addr))
164#define pte_unmap(pte) do { } while (0)
165
166#define set_pte(ptep, pte) cpu_set_pte(ptep, pte)
167
168#define set_pte_at(mm, addr, ptep, pteval) \
169 do { \
170 set_pte(ptep, pteval); \
171 } while (0)
172
173/*
174 * The following only work if pte_present() is true.
175 * Undefined behaviour if not..
176 */
177#define pte_present(pte) (pte_val(pte) & PTE_PRESENT)
178#define pte_write(pte) (pte_val(pte) & PTE_WRITE)
179#define pte_dirty(pte) (pte_val(pte) & PTE_DIRTY)
180#define pte_young(pte) (pte_val(pte) & PTE_YOUNG)
181#define pte_exec(pte) (pte_val(pte) & PTE_EXEC)
182#define pte_special(pte) (0)
183
184#define PTE_BIT_FUNC(fn, op) \
185static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
186
187PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
188PTE_BIT_FUNC(mkwrite, |= PTE_WRITE);
189PTE_BIT_FUNC(mkclean, &= ~PTE_DIRTY);
190PTE_BIT_FUNC(mkdirty, |= PTE_DIRTY);
191PTE_BIT_FUNC(mkold, &= ~PTE_YOUNG);
192PTE_BIT_FUNC(mkyoung, |= PTE_YOUNG);
193
194static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
195
196/*
197 * Mark the prot value as uncacheable.
198 */
199#define pgprot_noncached(prot) \
200 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
201#define pgprot_writecombine(prot) \
202 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
203#define pgprot_dmacoherent(prot) \
204 __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
205
206#define pmd_none(pmd) (!pmd_val(pmd))
207#define pmd_present(pmd) (pmd_val(pmd) & PMD_PRESENT)
208#define pmd_bad(pmd) (((pmd_val(pmd) & \
209 (PMD_PRESENT | PMD_TYPE_MASK)) \
210 != (PMD_PRESENT | PMD_TYPE_TABLE)))
211
212#define set_pmd(pmdpd, pmdval) \
213 do { \
214 *(pmdpd) = pmdval; \
215 } while (0)
216
217#define pmd_clear(pmdp) \
218 do { \
219 set_pmd(pmdp, __pmd(0));\
220 clean_pmd_entry(pmdp); \
221 } while (0)
222
223#define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK))
224#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd)))
225
226/*
227 * Conversion functions: convert a page and protection to a page entry,
228 * and a page entry and page directory to the page they refer to.
229 */
230#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)
231
232/* to find an entry in a page-table-directory */
233#define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
234
235#define pgd_offset(mm, addr) ((mm)->pgd+pgd_index(addr))
236
237/* to find an entry in a kernel page-table-directory */
238#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
239
240/* Find an entry in the third-level page table.. */
241#define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
242
243static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
244{
245 const unsigned long mask = PTE_EXEC | PTE_WRITE | PTE_READ;
246 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
247 return pte;
248}
249
250extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
251
252/*
253 * Encode and decode a swap entry. Swap entries are stored in the Linux
254 * page tables as follows:
255 *
256 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
257 * 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
258 * <--------------- offset --------------> <--- type --> 0 0 0 0 0
259 *
260 * This gives us up to 127 swap files and 32GB per swap file. Note that
261 * the offset field is always non-zero.
262 */
263#define __SWP_TYPE_SHIFT 5
264#define __SWP_TYPE_BITS 7
265#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
266#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
267
268#define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) \
269 & __SWP_TYPE_MASK)
270#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
271#define __swp_entry(type, offset) ((swp_entry_t) { \
272 ((type) << __SWP_TYPE_SHIFT) | \
273 ((offset) << __SWP_OFFSET_SHIFT) })
274
275#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
276#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
277
278/*
279 * It is an error for the kernel to have more swap files than we can
280 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES
281 * is increased beyond what we presently support.
282 */
283#define MAX_SWAPFILES_CHECK() \
284 BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
285
286/*
287 * Encode and decode a file entry. File entries are stored in the Linux
288 * page tables as follows:
289 *
290 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
291 * 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
292 * <----------------------- offset ----------------------> 1 0 0 0
293 */
294#define pte_file(pte) (pte_val(pte) & PTE_FILE)
295#define pte_to_pgoff(x) (pte_val(x) >> 4)
296#define pgoff_to_pte(x) __pte(((x) << 4) | PTE_FILE)
297
298#define PTE_FILE_MAX_BITS 28
299
300/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
301/* FIXME: this is not correct */
302#define kern_addr_valid(addr) (1)
303
304#include <asm-generic/pgtable.h>
305
306/*
307 * remap a physical page `pfn' of size `size' with page protection `prot'
308 * into virtual address `from'
309 */
310#define io_remap_pfn_range(vma, from, pfn, size, prot) \
311 remap_pfn_range(vma, from, pfn, size, prot)
312
313#define pgtable_cache_init() do { } while (0)
314
315#endif /* !__ASSEMBLY__ */
316
317#endif /* __UNICORE_PGTABLE_H__ */