2 * arch/arm/include/asm/pgtable.h
4 * Copyright (C) 1995-2002 Russell King
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 #ifndef _ASMARM_PGTABLE_H
11 #define _ASMARM_PGTABLE_H
13 #include <linux/const.h>
14 #include <asm/proc-fns.h>
18 #include <asm-generic/4level-fixup.h>
19 #include <asm/pgtable-nommu.h>
23 #define __ARCH_USE_5LEVEL_HACK
24 #include <asm-generic/pgtable-nopud.h>
25 #include <asm/memory.h>
26 #include <asm/pgtable-hwdef.h>
29 #include <asm/tlbflush.h>
31 #ifdef CONFIG_ARM_LPAE
32 #include <asm/pgtable-3level.h>
34 #include <asm/pgtable-2level.h>
38 * Just any arbitrary offset to the start of the vmalloc VM area: the
39 * current 8MB value just means that there will be a 8MB "hole" after the
40 * physical memory until the kernel virtual memory starts. That means that
41 * any out-of-bounds memory accesses will hopefully be caught.
42 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
43 * area for the same reason. ;)
45 #define VMALLOC_OFFSET (8*1024*1024)
46 #define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
47 #define VMALLOC_END 0xff800000UL
49 #define LIBRARY_TEXT_START 0x0c000000
52 extern void __pte_error(const char *file, int line, pte_t);
53 extern void __pmd_error(const char *file, int line, pmd_t);
54 extern void __pgd_error(const char *file, int line, pgd_t);
56 #define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte)
57 #define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd)
58 #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd)
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.
65 #define FIRST_USER_ADDRESS (PAGE_SIZE * 2)
68 * Use TASK_SIZE as the ceiling argument for free_pgtables() and
69 * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd
70 * page shared between user and kernel).
72 #ifdef CONFIG_ARM_LPAE
73 #define USER_PGTABLES_CEILING TASK_SIZE
77 * The pgprot_* and protection_map entries will be fixed up in runtime
78 * to include the cachable and bufferable bits based on memory policy,
79 * as well as any architecture dependent bits like global/ASID and SMP
80 * shared mapping bits.
82 #define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG
84 extern pgprot_t pgprot_user;
85 extern pgprot_t pgprot_kernel;
86 extern pgprot_t pgprot_hyp_device;
87 extern pgprot_t pgprot_s2;
88 extern pgprot_t pgprot_s2_device;
90 #define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
92 #define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY | L_PTE_NONE)
93 #define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
94 #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
95 #define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
96 #define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
97 #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
98 #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
99 #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
100 #define PAGE_KERNEL_EXEC pgprot_kernel
101 #define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_XN)
102 #define PAGE_HYP_EXEC _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY)
103 #define PAGE_HYP_RO _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY | L_PTE_XN)
104 #define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP)
105 #define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY | L_PTE_XN)
106 #define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_S2_RDONLY | L_PTE_XN)
108 #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE)
109 #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
110 #define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
111 #define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
112 #define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
113 #define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
114 #define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
116 #define __pgprot_modify(prot,mask,bits) \
117 __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
119 #define pgprot_noncached(prot) \
120 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
122 #define pgprot_writecombine(prot) \
123 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
125 #define pgprot_stronglyordered(prot) \
126 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
128 #define pgprot_device(prot) \
129 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_DEV_SHARED | L_PTE_SHARED | L_PTE_DIRTY | L_PTE_XN)
131 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
132 #define pgprot_dmacoherent(prot) \
133 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
134 #define __HAVE_PHYS_MEM_ACCESS_PROT
136 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
137 unsigned long size, pgprot_t vma_prot);
139 #define pgprot_dmacoherent(prot) \
140 __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
143 #endif /* __ASSEMBLY__ */
146 * The table below defines the page protection levels that we insert into our
147 * Linux page table version. These get translated into the best that the
148 * architecture can perform. Note that on most ARM hardware:
149 * 1) We cannot do execute protection
150 * 2) If we could do execute protection, then read is implied
151 * 3) write implies read permissions
153 #define __P000 __PAGE_NONE
154 #define __P001 __PAGE_READONLY
155 #define __P010 __PAGE_COPY
156 #define __P011 __PAGE_COPY
157 #define __P100 __PAGE_READONLY_EXEC
158 #define __P101 __PAGE_READONLY_EXEC
159 #define __P110 __PAGE_COPY_EXEC
160 #define __P111 __PAGE_COPY_EXEC
162 #define __S000 __PAGE_NONE
163 #define __S001 __PAGE_READONLY
164 #define __S010 __PAGE_SHARED
165 #define __S011 __PAGE_SHARED
166 #define __S100 __PAGE_READONLY_EXEC
167 #define __S101 __PAGE_READONLY_EXEC
168 #define __S110 __PAGE_SHARED_EXEC
169 #define __S111 __PAGE_SHARED_EXEC
173 * ZERO_PAGE is a global shared page that is always zero: used
174 * for zero-mapped memory areas etc..
176 extern struct page *empty_zero_page;
177 #define ZERO_PAGE(vaddr) (empty_zero_page)
180 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
182 /* to find an entry in a page-table-directory */
183 #define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
185 #define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
187 /* to find an entry in a kernel page-table-directory */
188 #define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
190 #define pmd_none(pmd) (!pmd_val(pmd))
192 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
194 return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
197 #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
199 #ifndef CONFIG_HIGHPTE
200 #define __pte_map(pmd) pmd_page_vaddr(*(pmd))
201 #define __pte_unmap(pte) do { } while (0)
203 #define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd)))
204 #define __pte_unmap(pte) kunmap_atomic(pte)
207 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
209 #define pte_offset_kernel(pmd,addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr))
211 #define pte_offset_map(pmd,addr) (__pte_map(pmd) + pte_index(addr))
212 #define pte_unmap(pte) __pte_unmap(pte)
214 #define pte_pfn(pte) ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
215 #define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
217 #define pte_page(pte) pfn_to_page(pte_pfn(pte))
218 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot)
220 #define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
222 #define pte_isset(pte, val) ((u32)(val) == (val) ? pte_val(pte) & (val) \
223 : !!(pte_val(pte) & (val)))
224 #define pte_isclear(pte, val) (!(pte_val(pte) & (val)))
226 #define pte_none(pte) (!pte_val(pte))
227 #define pte_present(pte) (pte_isset((pte), L_PTE_PRESENT))
228 #define pte_valid(pte) (pte_isset((pte), L_PTE_VALID))
229 #define pte_accessible(mm, pte) (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte))
230 #define pte_write(pte) (pte_isclear((pte), L_PTE_RDONLY))
231 #define pte_dirty(pte) (pte_isset((pte), L_PTE_DIRTY))
232 #define pte_young(pte) (pte_isset((pte), L_PTE_YOUNG))
233 #define pte_exec(pte) (pte_isclear((pte), L_PTE_XN))
235 #define pte_valid_user(pte) \
236 (pte_valid(pte) && pte_isset((pte), L_PTE_USER) && pte_young(pte))
238 static inline bool pte_access_permitted(pte_t pte, bool write)
240 pteval_t mask = L_PTE_PRESENT | L_PTE_USER;
241 pteval_t needed = mask;
244 mask |= L_PTE_RDONLY;
246 return (pte_val(pte) & mask) == needed;
248 #define pte_access_permitted pte_access_permitted
250 #if __LINUX_ARM_ARCH__ < 6
251 static inline void __sync_icache_dcache(pte_t pteval)
255 extern void __sync_icache_dcache(pte_t pteval);
258 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
259 pte_t *ptep, pte_t pteval)
261 unsigned long ext = 0;
263 if (addr < TASK_SIZE && pte_valid_user(pteval)) {
264 if (!pte_special(pteval))
265 __sync_icache_dcache(pteval);
269 set_pte_ext(ptep, pteval, ext);
272 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
274 pte_val(pte) &= ~pgprot_val(prot);
278 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
280 pte_val(pte) |= pgprot_val(prot);
284 static inline pte_t pte_wrprotect(pte_t pte)
286 return set_pte_bit(pte, __pgprot(L_PTE_RDONLY));
289 static inline pte_t pte_mkwrite(pte_t pte)
291 return clear_pte_bit(pte, __pgprot(L_PTE_RDONLY));
294 static inline pte_t pte_mkclean(pte_t pte)
296 return clear_pte_bit(pte, __pgprot(L_PTE_DIRTY));
299 static inline pte_t pte_mkdirty(pte_t pte)
301 return set_pte_bit(pte, __pgprot(L_PTE_DIRTY));
304 static inline pte_t pte_mkold(pte_t pte)
306 return clear_pte_bit(pte, __pgprot(L_PTE_YOUNG));
309 static inline pte_t pte_mkyoung(pte_t pte)
311 return set_pte_bit(pte, __pgprot(L_PTE_YOUNG));
314 static inline pte_t pte_mkexec(pte_t pte)
316 return clear_pte_bit(pte, __pgprot(L_PTE_XN));
319 static inline pte_t pte_mknexec(pte_t pte)
321 return set_pte_bit(pte, __pgprot(L_PTE_XN));
324 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
326 const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER |
327 L_PTE_NONE | L_PTE_VALID;
328 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
333 * Encode and decode a swap entry. Swap entries are stored in the Linux
334 * page tables as follows:
336 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
337 * 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
338 * <--------------- offset ------------------------> < type -> 0 0
340 * This gives us up to 31 swap files and 128GB per swap file. Note that
341 * the offset field is always non-zero.
343 #define __SWP_TYPE_SHIFT 2
344 #define __SWP_TYPE_BITS 5
345 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
346 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
348 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
349 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
350 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
352 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
353 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
356 * It is an error for the kernel to have more swap files than we can
357 * encode in the PTEs. This ensures that we know when MAX_SWAPFILES
358 * is increased beyond what we presently support.
360 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
362 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
363 /* FIXME: this is not correct */
364 #define kern_addr_valid(addr) (1)
366 #include <asm-generic/pgtable.h>
369 * We provide our own arch_get_unmapped_area to cope with VIPT caches.
371 #define HAVE_ARCH_UNMAPPED_AREA
372 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
374 #define pgtable_cache_init() do { } while (0)
376 #endif /* !__ASSEMBLY__ */
378 #endif /* CONFIG_MMU */
380 #endif /* _ASMARM_PGTABLE_H */