xref: /linux/arch/microblaze/include/asm/pgtable.h (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
4  * Copyright (C) 2008-2009 PetaLogix
5  * Copyright (C) 2006 Atmark Techno, Inc.
6  */
7 
8 #ifndef _ASM_MICROBLAZE_PGTABLE_H
9 #define _ASM_MICROBLAZE_PGTABLE_H
10 
11 #include <asm/setup.h>
12 
13 #ifndef __ASSEMBLY__
14 extern int mem_init_done;
15 #endif
16 
17 #include <asm-generic/pgtable-nopmd.h>
18 
19 #ifdef __KERNEL__
20 #ifndef __ASSEMBLY__
21 
22 #include <linux/sched.h>
23 #include <linux/threads.h>
24 #include <asm/processor.h>		/* For TASK_SIZE */
25 #include <asm/mmu.h>
26 #include <asm/page.h>
27 
28 #define FIRST_USER_ADDRESS	0UL
29 
30 extern unsigned long va_to_phys(unsigned long address);
31 extern pte_t *va_to_pte(unsigned long address);
32 
33 /*
34  * The following only work if pte_present() is true.
35  * Undefined behaviour if not..
36  */
37 
38 /* Start and end of the vmalloc area. */
39 /* Make sure to map the vmalloc area above the pinned kernel memory area
40    of 32Mb.  */
41 #define VMALLOC_START	(CONFIG_KERNEL_START + CONFIG_LOWMEM_SIZE)
42 #define VMALLOC_END	ioremap_bot
43 
44 #endif /* __ASSEMBLY__ */
45 
46 /*
47  * Macro to mark a page protection value as "uncacheable".
48  */
49 
50 #define _PAGE_CACHE_CTL	(_PAGE_GUARDED | _PAGE_NO_CACHE | \
51 							_PAGE_WRITETHRU)
52 
53 #define pgprot_noncached(prot) \
54 			(__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
55 					_PAGE_NO_CACHE | _PAGE_GUARDED))
56 
57 #define pgprot_noncached_wc(prot) \
58 			 (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
59 							_PAGE_NO_CACHE))
60 
61 /*
62  * The MicroBlaze MMU is identical to the PPC-40x MMU, and uses a hash
63  * table containing PTEs, together with a set of 16 segment registers, to
64  * define the virtual to physical address mapping.
65  *
66  * We use the hash table as an extended TLB, i.e. a cache of currently
67  * active mappings.  We maintain a two-level page table tree, much
68  * like that used by the i386, for the sake of the Linux memory
69  * management code.  Low-level assembler code in hashtable.S
70  * (procedure hash_page) is responsible for extracting ptes from the
71  * tree and putting them into the hash table when necessary, and
72  * updating the accessed and modified bits in the page table tree.
73  */
74 
75 /*
76  * The MicroBlaze processor has a TLB architecture identical to PPC-40x. The
77  * instruction and data sides share a unified, 64-entry, semi-associative
78  * TLB which is maintained totally under software control. In addition, the
79  * instruction side has a hardware-managed, 2,4, or 8-entry, fully-associative
80  * TLB which serves as a first level to the shared TLB. These two TLBs are
81  * known as the UTLB and ITLB, respectively (see "mmu.h" for definitions).
82  */
83 
84 /*
85  * The normal case is that PTEs are 32-bits and we have a 1-page
86  * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
87  *
88  */
89 
90 /* PGDIR_SHIFT determines what a top-level page table entry can map */
91 #define PGDIR_SHIFT	(PAGE_SHIFT + PTE_SHIFT)
92 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
93 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
94 
95 /*
96  * entries per page directory level: our page-table tree is two-level, so
97  * we don't really have any PMD directory.
98  */
99 #define PTRS_PER_PTE	(1 << PTE_SHIFT)
100 #define PTRS_PER_PMD	1
101 #define PTRS_PER_PGD	(1 << (32 - PGDIR_SHIFT))
102 
103 #define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
104 #define FIRST_USER_PGD_NR	0
105 
106 #define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
107 #define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)
108 
109 #define pte_ERROR(e) \
110 	printk(KERN_ERR "%s:%d: bad pte "PTE_FMT".\n", \
111 		__FILE__, __LINE__, pte_val(e))
112 #define pgd_ERROR(e) \
113 	printk(KERN_ERR "%s:%d: bad pgd %08lx.\n", \
114 		__FILE__, __LINE__, pgd_val(e))
115 
116 /*
117  * Bits in a linux-style PTE.  These match the bits in the
118  * (hardware-defined) PTE as closely as possible.
119  */
120 
121 /* There are several potential gotchas here.  The hardware TLBLO
122  * field looks like this:
123  *
124  * 0  1  2  3  4  ... 18 19 20 21 22 23 24 25 26 27 28 29 30 31
125  * RPN.....................  0  0 EX WR ZSEL.......  W  I  M  G
126  *
127  * Where possible we make the Linux PTE bits match up with this
128  *
129  * - bits 20 and 21 must be cleared, because we use 4k pages (4xx can
130  * support down to 1k pages), this is done in the TLBMiss exception
131  * handler.
132  * - We use only zones 0 (for kernel pages) and 1 (for user pages)
133  * of the 16 available.  Bit 24-26 of the TLB are cleared in the TLB
134  * miss handler.  Bit 27 is PAGE_USER, thus selecting the correct
135  * zone.
136  * - PRESENT *must* be in the bottom two bits because swap cache
137  * entries use the top 30 bits.  Because 4xx doesn't support SMP
138  * anyway, M is irrelevant so we borrow it for PAGE_PRESENT.  Bit 30
139  * is cleared in the TLB miss handler before the TLB entry is loaded.
140  * - All other bits of the PTE are loaded into TLBLO without
141  *  * modification, leaving us only the bits 20, 21, 24, 25, 26, 30 for
142  * software PTE bits.  We actually use bits 21, 24, 25, and
143  * 30 respectively for the software bits: ACCESSED, DIRTY, RW, and
144  * PRESENT.
145  */
146 
147 /* Definitions for MicroBlaze. */
148 #define	_PAGE_GUARDED	0x001	/* G: page is guarded from prefetch */
149 #define _PAGE_PRESENT	0x002	/* software: PTE contains a translation */
150 #define	_PAGE_NO_CACHE	0x004	/* I: caching is inhibited */
151 #define	_PAGE_WRITETHRU	0x008	/* W: caching is write-through */
152 #define	_PAGE_USER	0x010	/* matches one of the zone permission bits */
153 #define	_PAGE_RW	0x040	/* software: Writes permitted */
154 #define	_PAGE_DIRTY	0x080	/* software: dirty page */
155 #define _PAGE_HWWRITE	0x100	/* hardware: Dirty & RW, set in exception */
156 #define _PAGE_HWEXEC	0x200	/* hardware: EX permission */
157 #define _PAGE_ACCESSED	0x400	/* software: R: page referenced */
158 #define _PMD_PRESENT	PAGE_MASK
159 
160 /*
161  * Some bits are unused...
162  */
163 #ifndef _PAGE_HASHPTE
164 #define _PAGE_HASHPTE	0
165 #endif
166 #ifndef _PTE_NONE_MASK
167 #define _PTE_NONE_MASK	0
168 #endif
169 #ifndef _PAGE_SHARED
170 #define _PAGE_SHARED	0
171 #endif
172 #ifndef _PAGE_EXEC
173 #define _PAGE_EXEC	0
174 #endif
175 
176 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
177 
178 /*
179  * Note: the _PAGE_COHERENT bit automatically gets set in the hardware
180  * PTE if CONFIG_SMP is defined (hash_page does this); there is no need
181  * to have it in the Linux PTE, and in fact the bit could be reused for
182  * another purpose.  -- paulus.
183  */
184 #define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED)
185 #define _PAGE_WRENABLE	(_PAGE_RW | _PAGE_DIRTY | _PAGE_HWWRITE)
186 
187 #define _PAGE_KERNEL \
188 	(_PAGE_BASE | _PAGE_WRENABLE | _PAGE_SHARED | _PAGE_HWEXEC)
189 
190 #define _PAGE_IO	(_PAGE_KERNEL | _PAGE_NO_CACHE | _PAGE_GUARDED)
191 
192 #define PAGE_NONE	__pgprot(_PAGE_BASE)
193 #define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
194 #define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
195 #define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
196 #define PAGE_SHARED_X \
197 		__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
198 #define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
199 #define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
200 
201 #define PAGE_KERNEL	__pgprot(_PAGE_KERNEL)
202 #define PAGE_KERNEL_RO	__pgprot(_PAGE_BASE | _PAGE_SHARED)
203 #define PAGE_KERNEL_CI	__pgprot(_PAGE_IO)
204 
205 /*
206  * We consider execute permission the same as read.
207  * Also, write permissions imply read permissions.
208  */
209 #define __P000	PAGE_NONE
210 #define __P001	PAGE_READONLY_X
211 #define __P010	PAGE_COPY
212 #define __P011	PAGE_COPY_X
213 #define __P100	PAGE_READONLY
214 #define __P101	PAGE_READONLY_X
215 #define __P110	PAGE_COPY
216 #define __P111	PAGE_COPY_X
217 
218 #define __S000	PAGE_NONE
219 #define __S001	PAGE_READONLY_X
220 #define __S010	PAGE_SHARED
221 #define __S011	PAGE_SHARED_X
222 #define __S100	PAGE_READONLY
223 #define __S101	PAGE_READONLY_X
224 #define __S110	PAGE_SHARED
225 #define __S111	PAGE_SHARED_X
226 
227 #ifndef __ASSEMBLY__
228 /*
229  * ZERO_PAGE is a global shared page that is always zero: used
230  * for zero-mapped memory areas etc..
231  */
232 extern unsigned long empty_zero_page[1024];
233 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
234 
235 #endif /* __ASSEMBLY__ */
236 
237 #define pte_none(pte)		((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
238 #define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
239 #define pte_clear(mm, addr, ptep) \
240 	do { set_pte_at((mm), (addr), (ptep), __pte(0)); } while (0)
241 
242 #define pmd_none(pmd)		(!pmd_val(pmd))
243 #define	pmd_bad(pmd)		((pmd_val(pmd) & _PMD_PRESENT) == 0)
244 #define	pmd_present(pmd)	((pmd_val(pmd) & _PMD_PRESENT) != 0)
245 #define	pmd_clear(pmdp)		do { pmd_val(*(pmdp)) = 0; } while (0)
246 
247 #define pte_page(x)		(mem_map + (unsigned long) \
248 				((pte_val(x) - memory_start) >> PAGE_SHIFT))
249 #define PFN_SHIFT_OFFSET	(PAGE_SHIFT)
250 
251 #define pte_pfn(x)		(pte_val(x) >> PFN_SHIFT_OFFSET)
252 
253 #define pfn_pte(pfn, prot) \
254 	__pte(((pte_basic_t)(pfn) << PFN_SHIFT_OFFSET) | pgprot_val(prot))
255 
256 #ifndef __ASSEMBLY__
257 /*
258  * The following only work if pte_present() is true.
259  * Undefined behaviour if not..
260  */
261 static inline int pte_read(pte_t pte)  { return pte_val(pte) & _PAGE_USER; }
262 static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW; }
263 static inline int pte_exec(pte_t pte)  { return pte_val(pte) & _PAGE_EXEC; }
264 static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
265 static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
266 
267 static inline void pte_uncache(pte_t pte) { pte_val(pte) |= _PAGE_NO_CACHE; }
268 static inline void pte_cache(pte_t pte)   { pte_val(pte) &= ~_PAGE_NO_CACHE; }
269 
270 static inline pte_t pte_rdprotect(pte_t pte) \
271 		{ pte_val(pte) &= ~_PAGE_USER; return pte; }
272 static inline pte_t pte_wrprotect(pte_t pte) \
273 	{ pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); return pte; }
274 static inline pte_t pte_exprotect(pte_t pte) \
275 	{ pte_val(pte) &= ~_PAGE_EXEC; return pte; }
276 static inline pte_t pte_mkclean(pte_t pte) \
277 	{ pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HWWRITE); return pte; }
278 static inline pte_t pte_mkold(pte_t pte) \
279 	{ pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
280 
281 static inline pte_t pte_mkread(pte_t pte) \
282 	{ pte_val(pte) |= _PAGE_USER; return pte; }
283 static inline pte_t pte_mkexec(pte_t pte) \
284 	{ pte_val(pte) |= _PAGE_USER | _PAGE_EXEC; return pte; }
285 static inline pte_t pte_mkwrite(pte_t pte) \
286 	{ pte_val(pte) |= _PAGE_RW; return pte; }
287 static inline pte_t pte_mkdirty(pte_t pte) \
288 	{ pte_val(pte) |= _PAGE_DIRTY; return pte; }
289 static inline pte_t pte_mkyoung(pte_t pte) \
290 	{ pte_val(pte) |= _PAGE_ACCESSED; return pte; }
291 
292 /*
293  * Conversion functions: convert a page and protection to a page entry,
294  * and a page entry and page directory to the page they refer to.
295  */
296 
297 static inline pte_t mk_pte_phys(phys_addr_t physpage, pgprot_t pgprot)
298 {
299 	pte_t pte;
300 	pte_val(pte) = physpage | pgprot_val(pgprot);
301 	return pte;
302 }
303 
304 #define mk_pte(page, pgprot) \
305 ({									   \
306 	pte_t pte;							   \
307 	pte_val(pte) = (((page - mem_map) << PAGE_SHIFT) + memory_start) |  \
308 			pgprot_val(pgprot);				   \
309 	pte;								   \
310 })
311 
312 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
313 {
314 	pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot);
315 	return pte;
316 }
317 
318 /*
319  * Atomic PTE updates.
320  *
321  * pte_update clears and sets bit atomically, and returns
322  * the old pte value.
323  * The ((unsigned long)(p+1) - 4) hack is to get to the least-significant
324  * 32 bits of the PTE regardless of whether PTEs are 32 or 64 bits.
325  */
326 static inline unsigned long pte_update(pte_t *p, unsigned long clr,
327 				unsigned long set)
328 {
329 	unsigned long flags, old, tmp;
330 
331 	raw_local_irq_save(flags);
332 
333 	__asm__ __volatile__(	"lw	%0, %2, r0	\n"
334 				"andn	%1, %0, %3	\n"
335 				"or	%1, %1, %4	\n"
336 				"sw	%1, %2, r0	\n"
337 			: "=&r" (old), "=&r" (tmp)
338 			: "r" ((unsigned long)(p + 1) - 4), "r" (clr), "r" (set)
339 			: "cc");
340 
341 	raw_local_irq_restore(flags);
342 
343 	return old;
344 }
345 
346 /*
347  * set_pte stores a linux PTE into the linux page table.
348  */
349 static inline void set_pte(struct mm_struct *mm, unsigned long addr,
350 		pte_t *ptep, pte_t pte)
351 {
352 	*ptep = pte;
353 }
354 
355 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
356 		pte_t *ptep, pte_t pte)
357 {
358 	*ptep = pte;
359 }
360 
361 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
362 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
363 		unsigned long address, pte_t *ptep)
364 {
365 	return (pte_update(ptep, _PAGE_ACCESSED, 0) & _PAGE_ACCESSED) != 0;
366 }
367 
368 static inline int ptep_test_and_clear_dirty(struct mm_struct *mm,
369 		unsigned long addr, pte_t *ptep)
370 {
371 	return (pte_update(ptep, \
372 		(_PAGE_DIRTY | _PAGE_HWWRITE), 0) & _PAGE_DIRTY) != 0;
373 }
374 
375 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
376 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
377 		unsigned long addr, pte_t *ptep)
378 {
379 	return __pte(pte_update(ptep, ~_PAGE_HASHPTE, 0));
380 }
381 
382 /*static inline void ptep_set_wrprotect(struct mm_struct *mm,
383 		unsigned long addr, pte_t *ptep)
384 {
385 	pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), 0);
386 }*/
387 
388 static inline void ptep_mkdirty(struct mm_struct *mm,
389 		unsigned long addr, pte_t *ptep)
390 {
391 	pte_update(ptep, 0, _PAGE_DIRTY);
392 }
393 
394 /*#define pte_same(A,B)	(((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)*/
395 
396 /* Convert pmd entry to page */
397 /* our pmd entry is an effective address of pte table*/
398 /* returns effective address of the pmd entry*/
399 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
400 {
401 	return ((unsigned long) (pmd_val(pmd) & PAGE_MASK));
402 }
403 
404 /* returns struct *page of the pmd entry*/
405 #define pmd_page(pmd)	(pfn_to_page(__pa(pmd_val(pmd)) >> PAGE_SHIFT))
406 
407 /* Find an entry in the third-level page table.. */
408 
409 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
410 
411 /*
412  * Encode and decode a swap entry.
413  * Note that the bits we use in a PTE for representing a swap entry
414  * must not include the _PAGE_PRESENT bit, or the _PAGE_HASHPTE bit
415  * (if used).  -- paulus
416  */
417 #define __swp_type(entry)		((entry).val & 0x3f)
418 #define __swp_offset(entry)	((entry).val >> 6)
419 #define __swp_entry(type, offset) \
420 		((swp_entry_t) { (type) | ((offset) << 6) })
421 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) >> 2 })
422 #define __swp_entry_to_pte(x)	((pte_t) { (x).val << 2 })
423 
424 extern unsigned long iopa(unsigned long addr);
425 
426 /* Values for nocacheflag and cmode */
427 /* These are not used by the APUS kernel_map, but prevents
428  * compilation errors.
429  */
430 #define	IOMAP_FULL_CACHING	0
431 #define	IOMAP_NOCACHE_SER	1
432 #define	IOMAP_NOCACHE_NONSER	2
433 #define	IOMAP_NO_COPYBACK	3
434 
435 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
436 #define kern_addr_valid(addr)	(1)
437 
438 void do_page_fault(struct pt_regs *regs, unsigned long address,
439 		   unsigned long error_code);
440 
441 void mapin_ram(void);
442 int map_page(unsigned long va, phys_addr_t pa, int flags);
443 
444 extern int mem_init_done;
445 
446 asmlinkage void __init mmu_init(void);
447 
448 void __init *early_get_page(void);
449 
450 #endif /* __ASSEMBLY__ */
451 #endif /* __KERNEL__ */
452 
453 #ifndef __ASSEMBLY__
454 extern unsigned long ioremap_bot, ioremap_base;
455 
456 void setup_memory(void);
457 #endif /* __ASSEMBLY__ */
458 
459 #endif /* _ASM_MICROBLAZE_PGTABLE_H */
460