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/arch/unicore32/include/asm/pgtable.h

https://bitbucket.org/ndreys/linux-sunxi
C++ Header | 317 lines | 169 code | 53 blank | 95 comment | 6 complexity | 1bfb8e520ea5ef6dcdf929133a1c2c34 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  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__ */