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5dda4dc5 VG |
1 | /* |
2 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * vineetg: May 2011 | |
9 | * -Folded PAGE_PRESENT (used by VM) and PAGE_VALID (used by MMU) into 1. | |
10 | * They are semantically the same although in different contexts | |
11 | * VALID marks a TLB entry exists and it will only happen if PRESENT | |
12 | * - Utilise some unused free bits to confine PTE flags to 12 bits | |
13 | * This is a must for 4k pg-sz | |
14 | * | |
15 | * vineetg: Mar 2011 - changes to accomodate MMU TLB Page Descriptor mods | |
16 | * -TLB Locking never really existed, except for initial specs | |
17 | * -SILENT_xxx not needed for our port | |
18 | * -Per my request, MMU V3 changes the layout of some of the bits | |
19 | * to avoid a few shifts in TLB Miss handlers. | |
20 | * | |
21 | * vineetg: April 2010 | |
22 | * -PGD entry no longer contains any flags. If empty it is 0, otherwise has | |
23 | * Pg-Tbl ptr. Thus pmd_present(), pmd_valid(), pmd_set( ) become simpler | |
24 | * | |
25 | * vineetg: April 2010 | |
26 | * -Switched form 8:11:13 split for page table lookup to 11:8:13 | |
27 | * -this speeds up page table allocation itself as we now have to memset 1K | |
28 | * instead of 8k per page table. | |
29 | * -TODO: Right now page table alloc is 8K and rest 7K is unused | |
30 | * need to optimise it | |
31 | * | |
32 | * Amit Bhor, Sameer Dhavale: Codito Technologies 2004 | |
33 | */ | |
34 | ||
35 | #ifndef _ASM_ARC_PGTABLE_H | |
36 | #define _ASM_ARC_PGTABLE_H | |
37 | ||
38 | #include <asm/page.h> | |
39 | #include <asm/mmu.h> | |
40 | #include <asm-generic/pgtable-nopmd.h> | |
41 | ||
42 | /************************************************************************** | |
43 | * Page Table Flags | |
44 | * | |
45 | * ARC700 MMU only deals with softare managed TLB entries. | |
46 | * Page Tables are purely for Linux VM's consumption and the bits below are | |
47 | * suited to that (uniqueness). Hence some are not implemented in the TLB and | |
48 | * some have different value in TLB. | |
49 | * e.g. MMU v2: K_READ bit is 8 and so is GLOBAL (possible becoz they live in | |
50 | * seperate PD0 and PD1, which combined forms a translation entry) | |
51 | * while for PTE perspective, they are 8 and 9 respectively | |
52 | * with MMU v3: Most bits (except SHARED) represent the exact hardware pos | |
53 | * (saves some bit shift ops in TLB Miss hdlrs) | |
54 | */ | |
55 | ||
56 | #if (CONFIG_ARC_MMU_VER <= 2) | |
57 | ||
58 | #define _PAGE_ACCESSED (1<<1) /* Page is accessed (S) */ | |
59 | #define _PAGE_CACHEABLE (1<<2) /* Page is cached (H) */ | |
64b703ef VG |
60 | #define _PAGE_EXECUTE (1<<3) /* Page has user execute perm (H) */ |
61 | #define _PAGE_WRITE (1<<4) /* Page has user write perm (H) */ | |
62 | #define _PAGE_READ (1<<5) /* Page has user read perm (H) */ | |
129cbed5 | 63 | #define _PAGE_DIRTY (1<<6) /* Page modified (dirty) (S) */ |
24830fc7 | 64 | #define _PAGE_SPECIAL (1<<7) |
d091fcb9 VG |
65 | #define _PAGE_GLOBAL (1<<8) /* Page is global (H) */ |
66 | #define _PAGE_PRESENT (1<<10) /* TLB entry is valid (H) */ | |
5dda4dc5 | 67 | |
64b703ef | 68 | #else /* MMU v3 onwards */ |
5dda4dc5 | 69 | |
5dda4dc5 | 70 | #define _PAGE_CACHEABLE (1<<0) /* Page is cached (H) */ |
64b703ef VG |
71 | #define _PAGE_EXECUTE (1<<1) /* Page has user execute perm (H) */ |
72 | #define _PAGE_WRITE (1<<2) /* Page has user write perm (H) */ | |
73 | #define _PAGE_READ (1<<3) /* Page has user read perm (H) */ | |
d091fcb9 | 74 | #define _PAGE_ACCESSED (1<<4) /* Page is accessed (S) */ |
129cbed5 | 75 | #define _PAGE_DIRTY (1<<5) /* Page modified (dirty) (S) */ |
24830fc7 | 76 | #define _PAGE_SPECIAL (1<<6) |
d7a512bf VG |
77 | |
78 | #if (CONFIG_ARC_MMU_VER >= 4) | |
79 | #define _PAGE_WTHRU (1<<7) /* Page cache mode write-thru (H) */ | |
80 | #endif | |
81 | ||
5dda4dc5 VG |
82 | #define _PAGE_GLOBAL (1<<8) /* Page is global (H) */ |
83 | #define _PAGE_PRESENT (1<<9) /* TLB entry is valid (H) */ | |
d7a512bf VG |
84 | |
85 | #if (CONFIG_ARC_MMU_VER >= 4) | |
86 | #define _PAGE_SZ (1<<10) /* Page Size indicator (H) */ | |
87 | #endif | |
88 | ||
d091fcb9 | 89 | #define _PAGE_SHARED_CODE (1<<11) /* Shared Code page with cmn vaddr |
5dda4dc5 | 90 | usable for shared TLB entries (H) */ |
5dda4dc5 VG |
91 | #endif |
92 | ||
64b703ef VG |
93 | /* vmalloc permissions */ |
94 | #define _K_PAGE_PERMS (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ | \ | |
a950549c | 95 | _PAGE_GLOBAL | _PAGE_PRESENT) |
5dda4dc5 | 96 | |
129cbed5 VG |
97 | #ifndef CONFIG_ARC_CACHE_PAGES |
98 | #undef _PAGE_CACHEABLE | |
99 | #define _PAGE_CACHEABLE 0 | |
5dda4dc5 VG |
100 | #endif |
101 | ||
129cbed5 VG |
102 | /* Defaults for every user page */ |
103 | #define ___DEF (_PAGE_PRESENT | _PAGE_CACHEABLE) | |
a950549c | 104 | |
5dda4dc5 | 105 | /* Set of bits not changed in pte_modify */ |
129cbed5 | 106 | #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) |
5dda4dc5 VG |
107 | |
108 | /* More Abbrevaited helpers */ | |
109 | #define PAGE_U_NONE __pgprot(___DEF) | |
110 | #define PAGE_U_R __pgprot(___DEF | _PAGE_READ) | |
111 | #define PAGE_U_W_R __pgprot(___DEF | _PAGE_READ | _PAGE_WRITE) | |
112 | #define PAGE_U_X_R __pgprot(___DEF | _PAGE_READ | _PAGE_EXECUTE) | |
113 | #define PAGE_U_X_W_R __pgprot(___DEF | _PAGE_READ | _PAGE_WRITE | \ | |
114 | _PAGE_EXECUTE) | |
115 | ||
116 | #define PAGE_SHARED PAGE_U_W_R | |
117 | ||
64b703ef VG |
118 | /* While kernel runs out of unstranslated space, vmalloc/modules use a chunk of |
119 | * user vaddr space - visible in all addr spaces, but kernel mode only | |
5dda4dc5 VG |
120 | * Thus Global, all-kernel-access, no-user-access, cached |
121 | */ | |
129cbed5 | 122 | #define PAGE_KERNEL __pgprot(_K_PAGE_PERMS | _PAGE_CACHEABLE) |
5dda4dc5 VG |
123 | |
124 | /* ioremap */ | |
a950549c | 125 | #define PAGE_KERNEL_NO_CACHE __pgprot(_K_PAGE_PERMS) |
5dda4dc5 | 126 | |
da1677b0 | 127 | /* Masks for actual TLB "PD"s */ |
64b703ef VG |
128 | #define PTE_BITS_IN_PD0 (_PAGE_GLOBAL | _PAGE_PRESENT) |
129 | #define PTE_BITS_RWX (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ) | |
130 | #define PTE_BITS_NON_RWX_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE) | |
da1677b0 | 131 | |
5dda4dc5 VG |
132 | /************************************************************************** |
133 | * Mapping of vm_flags (Generic VM) to PTE flags (arch specific) | |
134 | * | |
135 | * Certain cases have 1:1 mapping | |
136 | * e.g. __P101 means VM_READ, VM_EXEC and !VM_SHARED | |
137 | * which directly corresponds to PAGE_U_X_R | |
138 | * | |
139 | * Other rules which cause the divergence from 1:1 mapping | |
140 | * | |
141 | * 1. Although ARC700 can do exclusive execute/write protection (meaning R | |
142 | * can be tracked independet of X/W unlike some other CPUs), still to | |
143 | * keep things consistent with other archs: | |
144 | * -Write implies Read: W => R | |
145 | * -Execute implies Read: X => R | |
146 | * | |
147 | * 2. Pvt Writable doesn't have Write Enabled initially: Pvt-W => !W | |
148 | * This is to enable COW mechanism | |
149 | */ | |
150 | /* xwr */ | |
151 | #define __P000 PAGE_U_NONE | |
152 | #define __P001 PAGE_U_R | |
153 | #define __P010 PAGE_U_R /* Pvt-W => !W */ | |
154 | #define __P011 PAGE_U_R /* Pvt-W => !W */ | |
155 | #define __P100 PAGE_U_X_R /* X => R */ | |
156 | #define __P101 PAGE_U_X_R | |
157 | #define __P110 PAGE_U_X_R /* Pvt-W => !W and X => R */ | |
158 | #define __P111 PAGE_U_X_R /* Pvt-W => !W */ | |
159 | ||
160 | #define __S000 PAGE_U_NONE | |
161 | #define __S001 PAGE_U_R | |
162 | #define __S010 PAGE_U_W_R /* W => R */ | |
163 | #define __S011 PAGE_U_W_R | |
164 | #define __S100 PAGE_U_X_R /* X => R */ | |
165 | #define __S101 PAGE_U_X_R | |
166 | #define __S110 PAGE_U_X_W_R /* X => R */ | |
167 | #define __S111 PAGE_U_X_W_R | |
168 | ||
169 | /**************************************************************** | |
170 | * Page Table Lookup split | |
171 | * | |
172 | * We implement 2 tier paging and since this is all software, we are free | |
173 | * to customize the span of a PGD / PTE entry to suit us | |
174 | * | |
175 | * 32 bit virtual address | |
176 | * ------------------------------------------------------- | |
177 | * | BITS_FOR_PGD | BITS_FOR_PTE | BITS_IN_PAGE | | |
178 | * ------------------------------------------------------- | |
179 | * | | | | |
180 | * | | --> off in page frame | |
181 | * | | | |
182 | * | ---> index into Page Table | |
183 | * | | |
184 | * ----> index into Page Directory | |
185 | */ | |
186 | ||
187 | #define BITS_IN_PAGE PAGE_SHIFT | |
188 | ||
189 | /* Optimal Sizing of Pg Tbl - based on MMU page size */ | |
190 | #if defined(CONFIG_ARC_PAGE_SIZE_8K) | |
129cbed5 | 191 | #define BITS_FOR_PTE 8 /* 11:8:13 */ |
5dda4dc5 | 192 | #elif defined(CONFIG_ARC_PAGE_SIZE_16K) |
129cbed5 | 193 | #define BITS_FOR_PTE 8 /* 10:8:14 */ |
5dda4dc5 | 194 | #elif defined(CONFIG_ARC_PAGE_SIZE_4K) |
129cbed5 | 195 | #define BITS_FOR_PTE 9 /* 11:9:12 */ |
5dda4dc5 VG |
196 | #endif |
197 | ||
198 | #define BITS_FOR_PGD (32 - BITS_FOR_PTE - BITS_IN_PAGE) | |
199 | ||
129cbed5 | 200 | #define PGDIR_SHIFT (32 - BITS_FOR_PGD) |
5dda4dc5 VG |
201 | #define PGDIR_SIZE (1UL << PGDIR_SHIFT) /* vaddr span, not PDG sz */ |
202 | #define PGDIR_MASK (~(PGDIR_SIZE-1)) | |
203 | ||
204 | #ifdef __ASSEMBLY__ | |
205 | #define PTRS_PER_PTE (1 << BITS_FOR_PTE) | |
206 | #define PTRS_PER_PGD (1 << BITS_FOR_PGD) | |
207 | #else | |
208 | #define PTRS_PER_PTE (1UL << BITS_FOR_PTE) | |
209 | #define PTRS_PER_PGD (1UL << BITS_FOR_PGD) | |
210 | #endif | |
211 | /* | |
212 | * Number of entries a user land program use. | |
213 | * TASK_SIZE is the maximum vaddr that can be used by a userland program. | |
214 | */ | |
215 | #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) | |
216 | ||
217 | /* | |
218 | * No special requirements for lowest virtual address we permit any user space | |
219 | * mapping to be mapped at. | |
220 | */ | |
d016bf7e | 221 | #define FIRST_USER_ADDRESS 0UL |
5dda4dc5 VG |
222 | |
223 | ||
224 | /**************************************************************** | |
225 | * Bucket load of VM Helpers | |
226 | */ | |
227 | ||
228 | #ifndef __ASSEMBLY__ | |
229 | ||
230 | #define pte_ERROR(e) \ | |
231 | pr_crit("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e)) | |
232 | #define pgd_ERROR(e) \ | |
233 | pr_crit("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e)) | |
234 | ||
235 | /* the zero page used for uninitialized and anonymous pages */ | |
236 | extern char empty_zero_page[PAGE_SIZE]; | |
237 | #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) | |
238 | ||
239 | #define pte_unmap(pte) do { } while (0) | |
240 | #define pte_unmap_nested(pte) do { } while (0) | |
241 | ||
242 | #define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval)) | |
243 | #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval) | |
244 | ||
245 | /* find the page descriptor of the Page Tbl ref by PMD entry */ | |
246 | #define pmd_page(pmd) virt_to_page(pmd_val(pmd) & PAGE_MASK) | |
247 | ||
248 | /* find the logical addr (phy for ARC) of the Page Tbl ref by PMD entry */ | |
249 | #define pmd_page_vaddr(pmd) (pmd_val(pmd) & PAGE_MASK) | |
250 | ||
251 | /* In a 2 level sys, setup the PGD entry with PTE value */ | |
252 | static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) | |
253 | { | |
254 | pmd_val(*pmdp) = (unsigned long)ptep; | |
255 | } | |
256 | ||
257 | #define pte_none(x) (!pte_val(x)) | |
258 | #define pte_present(x) (pte_val(x) & _PAGE_PRESENT) | |
259 | #define pte_clear(mm, addr, ptep) set_pte_at(mm, addr, ptep, __pte(0)) | |
260 | ||
261 | #define pmd_none(x) (!pmd_val(x)) | |
262 | #define pmd_bad(x) ((pmd_val(x) & ~PAGE_MASK)) | |
263 | #define pmd_present(x) (pmd_val(x)) | |
264 | #define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) | |
265 | ||
266 | #define pte_page(x) (mem_map + \ | |
06f34e1c AB |
267 | (unsigned long)(((pte_val(x) - CONFIG_LINUX_LINK_BASE) >> \ |
268 | PAGE_SHIFT))) | |
5dda4dc5 VG |
269 | |
270 | #define mk_pte(page, pgprot) \ | |
271 | ({ \ | |
272 | pte_t pte; \ | |
273 | pte_val(pte) = __pa(page_address(page)) + pgprot_val(pgprot); \ | |
274 | pte; \ | |
275 | }) | |
276 | ||
5dda4dc5 VG |
277 | #define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT) |
278 | #define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))) | |
279 | #define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) | |
280 | ||
281 | /* | |
282 | * pte_offset gets a @ptr to PMD entry (PGD in our 2-tier paging system) | |
283 | * and returns ptr to PTE entry corresponding to @addr | |
284 | */ | |
285 | #define pte_offset(dir, addr) ((pte_t *)(pmd_page_vaddr(*dir)) +\ | |
286 | __pte_index(addr)) | |
287 | ||
288 | /* No mapping of Page Tables in high mem etc, so following same as above */ | |
289 | #define pte_offset_kernel(dir, addr) pte_offset(dir, addr) | |
290 | #define pte_offset_map(dir, addr) pte_offset(dir, addr) | |
291 | ||
292 | /* Zoo of pte_xxx function */ | |
293 | #define pte_read(pte) (pte_val(pte) & _PAGE_READ) | |
294 | #define pte_write(pte) (pte_val(pte) & _PAGE_WRITE) | |
129cbed5 | 295 | #define pte_dirty(pte) (pte_val(pte) & _PAGE_DIRTY) |
5dda4dc5 | 296 | #define pte_young(pte) (pte_val(pte) & _PAGE_ACCESSED) |
24830fc7 | 297 | #define pte_special(pte) (pte_val(pte) & _PAGE_SPECIAL) |
5dda4dc5 VG |
298 | |
299 | #define PTE_BIT_FUNC(fn, op) \ | |
300 | static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } | |
301 | ||
302 | PTE_BIT_FUNC(wrprotect, &= ~(_PAGE_WRITE)); | |
303 | PTE_BIT_FUNC(mkwrite, |= (_PAGE_WRITE)); | |
129cbed5 VG |
304 | PTE_BIT_FUNC(mkclean, &= ~(_PAGE_DIRTY)); |
305 | PTE_BIT_FUNC(mkdirty, |= (_PAGE_DIRTY)); | |
5dda4dc5 VG |
306 | PTE_BIT_FUNC(mkold, &= ~(_PAGE_ACCESSED)); |
307 | PTE_BIT_FUNC(mkyoung, |= (_PAGE_ACCESSED)); | |
308 | PTE_BIT_FUNC(exprotect, &= ~(_PAGE_EXECUTE)); | |
309 | PTE_BIT_FUNC(mkexec, |= (_PAGE_EXECUTE)); | |
24830fc7 | 310 | PTE_BIT_FUNC(mkspecial, |= (_PAGE_SPECIAL)); |
5dda4dc5 | 311 | |
24830fc7 | 312 | #define __HAVE_ARCH_PTE_SPECIAL |
5dda4dc5 VG |
313 | |
314 | static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) | |
315 | { | |
316 | return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); | |
317 | } | |
318 | ||
319 | /* Macro to mark a page protection as uncacheable */ | |
320 | #define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) & ~_PAGE_CACHEABLE)) | |
321 | ||
322 | static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, | |
323 | pte_t *ptep, pte_t pteval) | |
324 | { | |
325 | set_pte(ptep, pteval); | |
326 | } | |
327 | ||
328 | /* | |
329 | * All kernel related VM pages are in init's mm. | |
330 | */ | |
331 | #define pgd_offset_k(address) pgd_offset(&init_mm, address) | |
332 | #define pgd_index(addr) ((addr) >> PGDIR_SHIFT) | |
333 | #define pgd_offset(mm, addr) (((mm)->pgd)+pgd_index(addr)) | |
334 | ||
335 | /* | |
336 | * Macro to quickly access the PGD entry, utlising the fact that some | |
337 | * arch may cache the pointer to Page Directory of "current" task | |
338 | * in a MMU register | |
339 | * | |
340 | * Thus task->mm->pgd (3 pointer dereferences, cache misses etc simply | |
341 | * becomes read a register | |
342 | * | |
343 | * ********CAUTION*******: | |
344 | * Kernel code might be dealing with some mm_struct of NON "current" | |
345 | * Thus use this macro only when you are certain that "current" is current | |
346 | * e.g. when dealing with signal frame setup code etc | |
347 | */ | |
41195d23 | 348 | #ifndef CONFIG_SMP |
5dda4dc5 VG |
349 | #define pgd_offset_fast(mm, addr) \ |
350 | ({ \ | |
351 | pgd_t *pgd_base = (pgd_t *) read_aux_reg(ARC_REG_SCRATCH_DATA0); \ | |
352 | pgd_base + pgd_index(addr); \ | |
353 | }) | |
41195d23 VG |
354 | #else |
355 | #define pgd_offset_fast(mm, addr) pgd_offset(mm, addr) | |
356 | #endif | |
5dda4dc5 VG |
357 | |
358 | extern void paging_init(void); | |
359 | extern pgd_t swapper_pg_dir[] __aligned(PAGE_SIZE); | |
360 | void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, | |
361 | pte_t *ptep); | |
362 | ||
363 | /* Encode swap {type,off} tuple into PTE | |
364 | * We reserve 13 bits for 5-bit @type, keeping bits 12-5 zero, ensuring that | |
18747151 | 365 | * PAGE_PRESENT is zero in a PTE holding swap "identifier" |
5dda4dc5 VG |
366 | */ |
367 | #define __swp_entry(type, off) ((swp_entry_t) { \ | |
368 | ((type) & 0x1f) | ((off) << 13) }) | |
369 | ||
370 | /* Decode a PTE containing swap "identifier "into constituents */ | |
371 | #define __swp_type(pte_lookalike) (((pte_lookalike).val) & 0x1f) | |
372 | #define __swp_offset(pte_lookalike) ((pte_lookalike).val << 13) | |
373 | ||
374 | /* NOPs, to keep generic kernel happy */ | |
375 | #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) | |
376 | #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) | |
377 | ||
378 | #define kern_addr_valid(addr) (1) | |
379 | ||
380 | /* | |
381 | * remap a physical page `pfn' of size `size' with page protection `prot' | |
382 | * into virtual address `from' | |
383 | */ | |
5dda4dc5 VG |
384 | #include <asm-generic/pgtable.h> |
385 | ||
5bba49f5 VG |
386 | /* to cope with aliasing VIPT cache */ |
387 | #define HAVE_ARCH_UNMAPPED_AREA | |
388 | ||
5dda4dc5 VG |
389 | /* |
390 | * No page table caches to initialise | |
391 | */ | |
392 | #define pgtable_cache_init() do { } while (0) | |
393 | ||
394 | #endif /* __ASSEMBLY__ */ | |
395 | ||
396 | #endif |