2 * CRIS pgtable.h - macros and functions to manipulate page tables.
5 #ifndef _CRIS_PGTABLE_H
6 #define _CRIS_PGTABLE_H
9 #define __ARCH_USE_5LEVEL_HACK
10 #include <asm-generic/pgtable-nopmd.h>
13 #include <linux/sched/mm.h>
16 #include <arch/pgtable.h>
19 * The Linux memory management assumes a three-level page table setup. On
20 * CRIS, we use that, but "fold" the mid level into the top-level page
21 * table. Since the MMU TLB is software loaded through an interrupt, it
22 * supports any page table structure, so we could have used a three-level
23 * setup, but for the amounts of memory we normally use, a two-level is
24 * probably more efficient.
26 * This file contains the functions and defines necessary to modify and use
27 * the CRIS page table tree.
30 extern void paging_init(void);
33 /* Certain architectures need to do special things when pte's
34 * within a page table are directly modified. Thus, the following
35 * hook is made available.
37 #define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))
38 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
41 * (pmds are folded into pgds so this doesn't get actually called,
42 * but the define is needed for a generic inline function.)
44 #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
45 #define set_pgu(pudptr, pudval) (*(pudptr) = pudval)
47 /* PGDIR_SHIFT determines the size of the area a second-level page table can
48 * map. It is equal to the page size times the number of PTE's that fit in
49 * a PMD page. A PTE is 4-bytes in CRIS. Hence the following number.
52 #define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2))
53 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
54 #define PGDIR_MASK (~(PGDIR_SIZE-1))
57 * entries per page directory level: we use a two-level, so
58 * we don't really have any PMD directory physically.
59 * pointers are 4 bytes so we can use the page size and
60 * divide it by 4 (shift by 2).
62 #define PTRS_PER_PTE (1UL << (PAGE_SHIFT-2))
63 #define PTRS_PER_PGD (1UL << (PAGE_SHIFT-2))
65 /* calculate how many PGD entries a user-level program can use
66 * the first mappable virtual address is 0
67 * (TASK_SIZE is the maximum virtual address space)
70 #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE)
71 #define FIRST_USER_ADDRESS 0UL
73 /* zero page used for uninitialized stuff */
75 extern unsigned long empty_zero_page
;
76 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
79 /* number of bits that fit into a memory pointer */
80 #define BITS_PER_PTR (8*sizeof(unsigned long))
82 /* to align the pointer to a pointer address */
83 #define PTR_MASK (~(sizeof(void*)-1))
85 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
86 /* 64-bit machines, beware! SRB. */
87 #define SIZEOF_PTR_LOG2 2
89 /* to find an entry in a page-table */
90 #define PAGE_PTR(address) \
91 ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)
93 /* to set the page-dir */
94 #define SET_PAGE_DIR(tsk,pgdir)
96 #define pte_none(x) (!pte_val(x))
97 #define pte_present(x) (pte_val(x) & _PAGE_PRESENT)
98 #define pte_clear(mm,addr,xp) do { pte_val(*(xp)) = 0; } while (0)
100 #define pmd_none(x) (!pmd_val(x))
101 /* by removing the _PAGE_KERNEL bit from the comparison, the same pmd_bad
102 * works for both _PAGE_TABLE and _KERNPG_TABLE pmd entries.
104 #define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_KERNEL)) != _PAGE_TABLE)
105 #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
106 #define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0)
111 * The following only work if pte_present() is true.
112 * Undefined behaviour if not..
115 static inline int pte_write(pte_t pte
) { return pte_val(pte
) & _PAGE_WRITE
; }
116 static inline int pte_dirty(pte_t pte
) { return pte_val(pte
) & _PAGE_MODIFIED
; }
117 static inline int pte_young(pte_t pte
) { return pte_val(pte
) & _PAGE_ACCESSED
; }
118 static inline int pte_special(pte_t pte
) { return 0; }
120 static inline pte_t
pte_wrprotect(pte_t pte
)
122 pte_val(pte
) &= ~(_PAGE_WRITE
| _PAGE_SILENT_WRITE
);
126 static inline pte_t
pte_mkclean(pte_t pte
)
128 pte_val(pte
) &= ~(_PAGE_MODIFIED
| _PAGE_SILENT_WRITE
);
132 static inline pte_t
pte_mkold(pte_t pte
)
134 pte_val(pte
) &= ~(_PAGE_ACCESSED
| _PAGE_SILENT_READ
);
138 static inline pte_t
pte_mkwrite(pte_t pte
)
140 pte_val(pte
) |= _PAGE_WRITE
;
141 if (pte_val(pte
) & _PAGE_MODIFIED
)
142 pte_val(pte
) |= _PAGE_SILENT_WRITE
;
146 static inline pte_t
pte_mkdirty(pte_t pte
)
148 pte_val(pte
) |= _PAGE_MODIFIED
;
149 if (pte_val(pte
) & _PAGE_WRITE
)
150 pte_val(pte
) |= _PAGE_SILENT_WRITE
;
154 static inline pte_t
pte_mkyoung(pte_t pte
)
156 pte_val(pte
) |= _PAGE_ACCESSED
;
157 if (pte_val(pte
) & _PAGE_READ
)
159 pte_val(pte
) |= _PAGE_SILENT_READ
;
160 if ((pte_val(pte
) & (_PAGE_WRITE
| _PAGE_MODIFIED
)) ==
161 (_PAGE_WRITE
| _PAGE_MODIFIED
))
162 pte_val(pte
) |= _PAGE_SILENT_WRITE
;
166 static inline pte_t
pte_mkspecial(pte_t pte
) { return pte
; }
169 * Conversion functions: convert a page and protection to a page entry,
170 * and a page entry and page directory to the page they refer to.
173 /* What actually goes as arguments to the various functions is less than
174 * obvious, but a rule of thumb is that struct page's goes as struct page *,
175 * really physical DRAM addresses are unsigned long's, and DRAM "virtual"
176 * addresses (the 0xc0xxxxxx's) goes as void *'s.
179 static inline pte_t
__mk_pte(void * page
, pgprot_t pgprot
)
182 /* the PTE needs a physical address */
183 pte_val(pte
) = __pa(page
) | pgprot_val(pgprot
);
187 #define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))
189 #define mk_pte_phys(physpage, pgprot) \
193 pte_val(__pte) = (physpage) + pgprot_val(pgprot); \
197 static inline pte_t
pte_modify(pte_t pte
, pgprot_t newprot
)
198 { pte_val(pte
) = (pte_val(pte
) & _PAGE_CHG_MASK
) | pgprot_val(newprot
); return pte
; }
200 #define pgprot_noncached(prot) __pgprot((pgprot_val(prot) | _PAGE_NO_CACHE))
203 /* pte_val refers to a page in the 0x4xxxxxxx physical DRAM interval
204 * __pte_page(pte_val) refers to the "virtual" DRAM interval
205 * pte_pagenr refers to the page-number counted starting from the virtual DRAM start
208 static inline unsigned long __pte_page(pte_t pte
)
210 /* the PTE contains a physical address */
211 return (unsigned long)__va(pte_val(pte
) & PAGE_MASK
);
214 #define pte_pagenr(pte) ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT)
216 /* permanent address of a page */
218 #define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
219 #define pte_page(pte) (mem_map+pte_pagenr(pte))
221 /* only the pte's themselves need to point to physical DRAM (see above)
222 * the pagetable links are purely handled within the kernel SW and thus
223 * don't need the __pa and __va transformations.
226 static inline void pmd_set(pmd_t
* pmdp
, pte_t
* ptep
)
227 { pmd_val(*pmdp
) = _PAGE_TABLE
| (unsigned long) ptep
; }
229 #define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
230 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
232 /* to find an entry in a page-table-directory. */
233 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
235 /* to find an entry in a page-table-directory */
236 static inline pgd_t
* pgd_offset(const struct mm_struct
*mm
, unsigned long address
)
238 return mm
->pgd
+ pgd_index(address
);
241 /* to find an entry in a kernel page-table-directory */
242 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
244 /* Find an entry in the third-level page table.. */
245 #define __pte_offset(address) \
246 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
247 #define pte_offset_kernel(dir, address) \
248 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
249 #define pte_offset_map(dir, address) \
250 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
252 #define pte_unmap(pte) do { } while (0)
253 #define pte_pfn(x) ((unsigned long)(__va((x).pte)) >> PAGE_SHIFT)
254 #define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
256 #define pte_ERROR(e) \
257 printk("%s:%d: bad pte %p(%08lx).\n", __FILE__, __LINE__, &(e), pte_val(e))
258 #define pgd_ERROR(e) \
259 printk("%s:%d: bad pgd %p(%08lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
262 extern pgd_t swapper_pg_dir
[PTRS_PER_PGD
]; /* defined in head.S */
265 * CRIS doesn't have any external MMU info: the kernel page
266 * tables contain all the necessary information.
268 * Actually I am not sure on what this could be used for.
270 static inline void update_mmu_cache(struct vm_area_struct
* vma
,
271 unsigned long address
, pte_t
*ptep
)
275 /* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
276 /* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */
278 #define __swp_type(x) (((x).val >> 5) & 0x7f)
279 #define __swp_offset(x) ((x).val >> 12)
280 #define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 5) | ((offset) << 12) })
281 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
282 #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
284 #define kern_addr_valid(addr) (1)
286 #include <asm-generic/pgtable.h>
289 * No page table caches to initialise
291 #define pgtable_cache_init() do { } while (0)
293 typedef pte_t
*pte_addr_t
;
295 #endif /* __ASSEMBLY__ */
296 #endif /* _CRIS_PGTABLE_H */