xref: /openbmc/linux/arch/parisc/include/asm/pgtable.h (revision 0c6dfa75)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _PARISC_PGTABLE_H
3 #define _PARISC_PGTABLE_H
4 
5 #include <asm/page.h>
6 
7 #if CONFIG_PGTABLE_LEVELS == 3
8 #include <asm-generic/pgtable-nopud.h>
9 #elif CONFIG_PGTABLE_LEVELS == 2
10 #include <asm-generic/pgtable-nopmd.h>
11 #endif
12 
13 #include <asm/fixmap.h>
14 
15 #ifndef __ASSEMBLY__
16 /*
17  * we simulate an x86-style page table for the linux mm code
18  */
19 
20 #include <linux/bitops.h>
21 #include <linux/spinlock.h>
22 #include <linux/mm_types.h>
23 #include <asm/processor.h>
24 #include <asm/cache.h>
25 
26 /* This is for the serialization of PxTLB broadcasts. At least on the N class
27  * systems, only one PxTLB inter processor broadcast can be active at any one
28  * time on the Merced bus. */
29 extern spinlock_t pa_tlb_flush_lock;
30 #if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
31 extern int pa_serialize_tlb_flushes;
32 #else
33 #define pa_serialize_tlb_flushes        (0)
34 #endif
35 
36 #define purge_tlb_start(flags)  do { \
37 	if (pa_serialize_tlb_flushes)	\
38 		spin_lock_irqsave(&pa_tlb_flush_lock, flags); \
39 	else \
40 		local_irq_save(flags);	\
41 	} while (0)
42 #define purge_tlb_end(flags)	do { \
43 	if (pa_serialize_tlb_flushes)	\
44 		spin_unlock_irqrestore(&pa_tlb_flush_lock, flags); \
45 	else \
46 		local_irq_restore(flags); \
47 	} while (0)
48 
49 /* Purge data and instruction TLB entries. The TLB purge instructions
50  * are slow on SMP machines since the purge must be broadcast to all CPUs.
51  */
52 
53 static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
54 {
55 	unsigned long flags;
56 
57 	purge_tlb_start(flags);
58 	mtsp(mm->context.space_id, SR_TEMP1);
59 	pdtlb(SR_TEMP1, addr);
60 	pitlb(SR_TEMP1, addr);
61 	purge_tlb_end(flags);
62 }
63 
64 extern void __update_cache(pte_t pte);
65 
66 /* Certain architectures need to do special things when PTEs
67  * within a page table are directly modified.  Thus, the following
68  * hook is made available.
69  */
70 #define set_pte(pteptr, pteval)			\
71 	do {					\
72 		*(pteptr) = (pteval);		\
73 		mb();				\
74 	} while(0)
75 
76 #endif /* !__ASSEMBLY__ */
77 
78 #define pte_ERROR(e) \
79 	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
80 #if CONFIG_PGTABLE_LEVELS == 3
81 #define pmd_ERROR(e) \
82 	printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, (unsigned long)pmd_val(e))
83 #endif
84 #define pgd_ERROR(e) \
85 	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, (unsigned long)pgd_val(e))
86 
87 /* This is the size of the initially mapped kernel memory */
88 #if defined(CONFIG_64BIT)
89 #define KERNEL_INITIAL_ORDER	26	/* 1<<26 = 64MB */
90 #else
91 #define KERNEL_INITIAL_ORDER	25	/* 1<<25 = 32MB */
92 #endif
93 #define KERNEL_INITIAL_SIZE	(1 << KERNEL_INITIAL_ORDER)
94 
95 #if CONFIG_PGTABLE_LEVELS == 3
96 #define PMD_TABLE_ORDER	1
97 #define PGD_TABLE_ORDER	0
98 #else
99 #define PGD_TABLE_ORDER	1
100 #endif
101 
102 /* Definitions for 3rd level (we use PLD here for Page Lower directory
103  * because PTE_SHIFT is used lower down to mean shift that has to be
104  * done to get usable bits out of the PTE) */
105 #define PLD_SHIFT	PAGE_SHIFT
106 #define PLD_SIZE	PAGE_SIZE
107 #define BITS_PER_PTE	(PAGE_SHIFT - BITS_PER_PTE_ENTRY)
108 #define PTRS_PER_PTE    (1UL << BITS_PER_PTE)
109 
110 /* Definitions for 2nd level */
111 #if CONFIG_PGTABLE_LEVELS == 3
112 #define PMD_SHIFT       (PLD_SHIFT + BITS_PER_PTE)
113 #define PMD_SIZE	(1UL << PMD_SHIFT)
114 #define PMD_MASK	(~(PMD_SIZE-1))
115 #define BITS_PER_PMD	(PAGE_SHIFT + PMD_TABLE_ORDER - BITS_PER_PMD_ENTRY)
116 #define PTRS_PER_PMD    (1UL << BITS_PER_PMD)
117 #else
118 #define BITS_PER_PMD	0
119 #endif
120 
121 /* Definitions for 1st level */
122 #define PGDIR_SHIFT	(PLD_SHIFT + BITS_PER_PTE + BITS_PER_PMD)
123 #if (PGDIR_SHIFT + PAGE_SHIFT + PGD_TABLE_ORDER - BITS_PER_PGD_ENTRY) > BITS_PER_LONG
124 #define BITS_PER_PGD	(BITS_PER_LONG - PGDIR_SHIFT)
125 #else
126 #define BITS_PER_PGD	(PAGE_SHIFT + PGD_TABLE_ORDER - BITS_PER_PGD_ENTRY)
127 #endif
128 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
129 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
130 #define PTRS_PER_PGD    (1UL << BITS_PER_PGD)
131 #define USER_PTRS_PER_PGD       PTRS_PER_PGD
132 
133 #ifdef CONFIG_64BIT
134 #define MAX_ADDRBITS	(PGDIR_SHIFT + BITS_PER_PGD)
135 #define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
136 #define SPACEID_SHIFT	(MAX_ADDRBITS - 32)
137 #else
138 #define MAX_ADDRBITS	(BITS_PER_LONG)
139 #define MAX_ADDRESS	(1ULL << MAX_ADDRBITS)
140 #define SPACEID_SHIFT	0
141 #endif
142 
143 /* This calculates the number of initial pages we need for the initial
144  * page tables */
145 #if (KERNEL_INITIAL_ORDER) >= (PLD_SHIFT + BITS_PER_PTE)
146 # define PT_INITIAL	(1 << (KERNEL_INITIAL_ORDER - PLD_SHIFT - BITS_PER_PTE))
147 #else
148 # define PT_INITIAL	(1)  /* all initial PTEs fit into one page */
149 #endif
150 
151 /*
152  * pgd entries used up by user/kernel:
153  */
154 
155 /* NB: The tlb miss handlers make certain assumptions about the order */
156 /*     of the following bits, so be careful (One example, bits 25-31  */
157 /*     are moved together in one instruction).                        */
158 
159 #define _PAGE_READ_BIT     31   /* (0x001) read access allowed */
160 #define _PAGE_WRITE_BIT    30   /* (0x002) write access allowed */
161 #define _PAGE_EXEC_BIT     29   /* (0x004) execute access allowed */
162 #define _PAGE_GATEWAY_BIT  28   /* (0x008) privilege promotion allowed */
163 #define _PAGE_DMB_BIT      27   /* (0x010) Data Memory Break enable (B bit) */
164 #define _PAGE_DIRTY_BIT    26   /* (0x020) Page Dirty (D bit) */
165 #define _PAGE_REFTRAP_BIT  25   /* (0x040) Page Ref. Trap enable (T bit) */
166 #define _PAGE_NO_CACHE_BIT 24   /* (0x080) Uncached Page (U bit) */
167 #define _PAGE_ACCESSED_BIT 23   /* (0x100) Software: Page Accessed */
168 #define _PAGE_PRESENT_BIT  22   /* (0x200) Software: translation valid */
169 #define _PAGE_HPAGE_BIT    21   /* (0x400) Software: Huge Page */
170 #define _PAGE_USER_BIT     20   /* (0x800) Software: User accessible page */
171 #ifdef CONFIG_HUGETLB_PAGE
172 #define _PAGE_SPECIAL_BIT  _PAGE_DMB_BIT  /* DMB feature is currently unused */
173 #else
174 #define _PAGE_SPECIAL_BIT  _PAGE_HPAGE_BIT /* use unused HUGE PAGE bit */
175 #endif
176 
177 /* N.B. The bits are defined in terms of a 32 bit word above, so the */
178 /*      following macro is ok for both 32 and 64 bit.                */
179 
180 #define xlate_pabit(x) (31 - x)
181 
182 /* this defines the shift to the usable bits in the PTE it is set so
183  * that the valid bits _PAGE_PRESENT_BIT and _PAGE_USER_BIT are set
184  * to zero */
185 #define PTE_SHIFT	   	xlate_pabit(_PAGE_USER_BIT)
186 
187 /* PFN_PTE_SHIFT defines the shift of a PTE value to access the PFN field */
188 #define PFN_PTE_SHIFT		12
189 
190 #define _PAGE_READ     (1 << xlate_pabit(_PAGE_READ_BIT))
191 #define _PAGE_WRITE    (1 << xlate_pabit(_PAGE_WRITE_BIT))
192 #define _PAGE_RW       (_PAGE_READ | _PAGE_WRITE)
193 #define _PAGE_EXEC     (1 << xlate_pabit(_PAGE_EXEC_BIT))
194 #define _PAGE_GATEWAY  (1 << xlate_pabit(_PAGE_GATEWAY_BIT))
195 #define _PAGE_DMB      (1 << xlate_pabit(_PAGE_DMB_BIT))
196 #define _PAGE_DIRTY    (1 << xlate_pabit(_PAGE_DIRTY_BIT))
197 #define _PAGE_REFTRAP  (1 << xlate_pabit(_PAGE_REFTRAP_BIT))
198 #define _PAGE_NO_CACHE (1 << xlate_pabit(_PAGE_NO_CACHE_BIT))
199 #define _PAGE_ACCESSED (1 << xlate_pabit(_PAGE_ACCESSED_BIT))
200 #define _PAGE_PRESENT  (1 << xlate_pabit(_PAGE_PRESENT_BIT))
201 #define _PAGE_HUGE     (1 << xlate_pabit(_PAGE_HPAGE_BIT))
202 #define _PAGE_USER     (1 << xlate_pabit(_PAGE_USER_BIT))
203 #define _PAGE_SPECIAL  (1 << xlate_pabit(_PAGE_SPECIAL_BIT))
204 
205 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)
206 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_SPECIAL)
207 #define _PAGE_KERNEL_RO	(_PAGE_PRESENT | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED)
208 #define _PAGE_KERNEL_EXEC	(_PAGE_KERNEL_RO | _PAGE_EXEC)
209 #define _PAGE_KERNEL_RWX	(_PAGE_KERNEL_EXEC | _PAGE_WRITE)
210 #define _PAGE_KERNEL		(_PAGE_KERNEL_RO | _PAGE_WRITE)
211 
212 /* We borrow bit 23 to store the exclusive marker in swap PTEs. */
213 #define _PAGE_SWP_EXCLUSIVE	_PAGE_ACCESSED
214 
215 /* The pgd/pmd contains a ptr (in phys addr space); since all pgds/pmds
216  * are page-aligned, we don't care about the PAGE_OFFSET bits, except
217  * for a few meta-information bits, so we shift the address to be
218  * able to effectively address 40/42/44-bits of physical address space
219  * depending on 4k/16k/64k PAGE_SIZE */
220 #define _PxD_PRESENT_BIT   31
221 #define _PxD_VALID_BIT     30
222 
223 #define PxD_FLAG_PRESENT  (1 << xlate_pabit(_PxD_PRESENT_BIT))
224 #define PxD_FLAG_VALID    (1 << xlate_pabit(_PxD_VALID_BIT))
225 #define PxD_FLAG_MASK     (0xf)
226 #define PxD_FLAG_SHIFT    (4)
227 #define PxD_VALUE_SHIFT   (PFN_PTE_SHIFT-PxD_FLAG_SHIFT)
228 
229 #ifndef __ASSEMBLY__
230 
231 #define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_USER)
232 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE)
233 /* Others seem to make this executable, I don't know if that's correct
234    or not.  The stack is mapped this way though so this is necessary
235    in the short term - dhd@linuxcare.com, 2000-08-08 */
236 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ)
237 #define PAGE_WRITEONLY  __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITE)
238 #define PAGE_EXECREAD   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_EXEC)
239 #define PAGE_COPY       PAGE_EXECREAD
240 #define PAGE_RWX        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)
241 #define PAGE_KERNEL	__pgprot(_PAGE_KERNEL)
242 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL_EXEC)
243 #define PAGE_KERNEL_RWX	__pgprot(_PAGE_KERNEL_RWX)
244 #define PAGE_KERNEL_RO	__pgprot(_PAGE_KERNEL_RO)
245 #define PAGE_KERNEL_UNC	__pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
246 #define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_GATEWAY| _PAGE_READ)
247 
248 
249 /*
250  * We could have an execute only page using "gateway - promote to priv
251  * level 3", but that is kind of silly. So, the way things are defined
252  * now, we must always have read permission for pages with execute
253  * permission. For the fun of it we'll go ahead and support write only
254  * pages.
255  */
256 
257 	 /*xwr*/
258 
259 extern pgd_t swapper_pg_dir[]; /* declared in init_task.c */
260 
261 /* initial page tables for 0-8MB for kernel */
262 
263 extern pte_t pg0[];
264 
265 /* zero page used for uninitialized stuff */
266 
267 extern unsigned long *empty_zero_page;
268 
269 /*
270  * ZERO_PAGE is a global shared page that is always zero: used
271  * for zero-mapped memory areas etc..
272  */
273 
274 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
275 
276 #define pte_none(x)     (pte_val(x) == 0)
277 #define pte_present(x)	(pte_val(x) & _PAGE_PRESENT)
278 #define pte_user(x)	(pte_val(x) & _PAGE_USER)
279 #define pte_clear(mm, addr, xp)  set_pte(xp, __pte(0))
280 
281 #define pmd_flag(x)	(pmd_val(x) & PxD_FLAG_MASK)
282 #define pmd_address(x)	((unsigned long)(pmd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
283 #define pud_flag(x)	(pud_val(x) & PxD_FLAG_MASK)
284 #define pud_address(x)	((unsigned long)(pud_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
285 #define pgd_flag(x)	(pgd_val(x) & PxD_FLAG_MASK)
286 #define pgd_address(x)	((unsigned long)(pgd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
287 
288 #define pmd_none(x)	(!pmd_val(x))
289 #define pmd_bad(x)	(!(pmd_flag(x) & PxD_FLAG_VALID))
290 #define pmd_present(x)	(pmd_flag(x) & PxD_FLAG_PRESENT)
291 static inline void pmd_clear(pmd_t *pmd) {
292 		set_pmd(pmd,  __pmd(0));
293 }
294 
295 
296 
297 #if CONFIG_PGTABLE_LEVELS == 3
298 #define pud_pgtable(pud) ((pmd_t *) __va(pud_address(pud)))
299 #define pud_page(pud)	virt_to_page((void *)pud_pgtable(pud))
300 
301 /* For 64 bit we have three level tables */
302 
303 #define pud_none(x)     (!pud_val(x))
304 #define pud_bad(x)      (!(pud_flag(x) & PxD_FLAG_VALID))
305 #define pud_present(x)  (pud_flag(x) & PxD_FLAG_PRESENT)
306 static inline void pud_clear(pud_t *pud) {
307 	set_pud(pud, __pud(0));
308 }
309 #endif
310 
311 /*
312  * The following only work if pte_present() is true.
313  * Undefined behaviour if not..
314  */
315 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
316 static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
317 static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_WRITE; }
318 static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
319 
320 static inline pte_t pte_mkclean(pte_t pte)	{ pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
321 static inline pte_t pte_mkold(pte_t pte)	{ pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
322 static inline pte_t pte_wrprotect(pte_t pte)	{ pte_val(pte) &= ~_PAGE_WRITE; return pte; }
323 static inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= _PAGE_DIRTY; return pte; }
324 static inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= _PAGE_ACCESSED; return pte; }
325 static inline pte_t pte_mkwrite_novma(pte_t pte)	{ pte_val(pte) |= _PAGE_WRITE; return pte; }
326 static inline pte_t pte_mkspecial(pte_t pte)	{ pte_val(pte) |= _PAGE_SPECIAL; return pte; }
327 
328 /*
329  * Huge pte definitions.
330  */
331 #ifdef CONFIG_HUGETLB_PAGE
332 #define pte_huge(pte)           (pte_val(pte) & _PAGE_HUGE)
333 #define pte_mkhuge(pte)         (__pte(pte_val(pte) | \
334 				 (parisc_requires_coherency() ? 0 : _PAGE_HUGE)))
335 #else
336 #define pte_huge(pte)           (0)
337 #define pte_mkhuge(pte)         (pte)
338 #endif
339 
340 
341 /*
342  * Conversion functions: convert a page and protection to a page entry,
343  * and a page entry and page directory to the page they refer to.
344  */
345 #define __mk_pte(addr,pgprot) \
346 ({									\
347 	pte_t __pte;							\
348 									\
349 	pte_val(__pte) = ((((addr)>>PAGE_SHIFT)<<PFN_PTE_SHIFT) + pgprot_val(pgprot));	\
350 									\
351 	__pte;								\
352 })
353 
354 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
355 
356 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
357 {
358 	pte_t pte;
359 	pte_val(pte) = (pfn << PFN_PTE_SHIFT) | pgprot_val(pgprot);
360 	return pte;
361 }
362 
363 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
364 { pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
365 
366 /* Permanent address of a page.  On parisc we don't have highmem. */
367 
368 #define pte_pfn(x)		(pte_val(x) >> PFN_PTE_SHIFT)
369 
370 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
371 
372 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
373 {
374 	return ((unsigned long) __va(pmd_address(pmd)));
375 }
376 
377 #define pmd_pfn(pmd)	(pmd_address(pmd) >> PAGE_SHIFT)
378 #define __pmd_page(pmd) ((unsigned long) __va(pmd_address(pmd)))
379 #define pmd_page(pmd)	virt_to_page((void *)__pmd_page(pmd))
380 
381 /* Find an entry in the second-level page table.. */
382 
383 extern void paging_init (void);
384 
385 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
386 		pte_t *ptep, pte_t pte, unsigned int nr)
387 {
388 	if (pte_present(pte) && pte_user(pte))
389 		__update_cache(pte);
390 	for (;;) {
391 		*ptep = pte;
392 		purge_tlb_entries(mm, addr);
393 		if (--nr == 0)
394 			break;
395 		ptep++;
396 		pte_val(pte) += 1 << PFN_PTE_SHIFT;
397 		addr += PAGE_SIZE;
398 	}
399 }
400 #define set_ptes set_ptes
401 
402 /* Used for deferring calls to flush_dcache_page() */
403 
404 #define PG_dcache_dirty         PG_arch_1
405 
406 #define update_mmu_cache_range(vmf, vma, addr, ptep, nr) __update_cache(*ptep)
407 #define update_mmu_cache(vma, addr, ptep) __update_cache(*ptep)
408 
409 /*
410  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
411  * are !pte_none() && !pte_present().
412  *
413  * Format of swap PTEs (32bit):
414  *
415  *                         1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
416  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
417  *   <---------------- offset -----------------> P E <ofs> < type ->
418  *
419  *   E is the exclusive marker that is not stored in swap entries.
420  *   _PAGE_PRESENT (P) must be 0.
421  *
422  *   For the 64bit version, the offset is extended by 32bit.
423  */
424 #define __swp_type(x)                     ((x).val & 0x1f)
425 #define __swp_offset(x)                   ( (((x).val >> 5) & 0x7) | \
426 					  (((x).val >> 10) << 3) )
427 #define __swp_entry(type, offset)         ((swp_entry_t) { \
428 					    ((type) & 0x1f) | \
429 					    ((offset & 0x7) << 5) | \
430 					    ((offset >> 3) << 10) })
431 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
432 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
433 
434 static inline int pte_swp_exclusive(pte_t pte)
435 {
436 	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
437 }
438 
439 static inline pte_t pte_swp_mkexclusive(pte_t pte)
440 {
441 	pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
442 	return pte;
443 }
444 
445 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
446 {
447 	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
448 	return pte;
449 }
450 
451 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
452 {
453 	pte_t pte;
454 
455 	if (!pte_young(*ptep))
456 		return 0;
457 
458 	pte = *ptep;
459 	if (!pte_young(pte)) {
460 		return 0;
461 	}
462 	set_pte(ptep, pte_mkold(pte));
463 	return 1;
464 }
465 
466 struct mm_struct;
467 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
468 {
469 	pte_t old_pte;
470 
471 	old_pte = *ptep;
472 	set_pte(ptep, __pte(0));
473 
474 	return old_pte;
475 }
476 
477 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
478 {
479 	set_pte(ptep, pte_wrprotect(*ptep));
480 }
481 
482 #define pte_same(A,B)	(pte_val(A) == pte_val(B))
483 
484 #endif /* !__ASSEMBLY__ */
485 
486 
487 /* TLB page size encoding - see table 3-1 in parisc20.pdf */
488 #define _PAGE_SIZE_ENCODING_4K		0
489 #define _PAGE_SIZE_ENCODING_16K		1
490 #define _PAGE_SIZE_ENCODING_64K		2
491 #define _PAGE_SIZE_ENCODING_256K	3
492 #define _PAGE_SIZE_ENCODING_1M		4
493 #define _PAGE_SIZE_ENCODING_4M		5
494 #define _PAGE_SIZE_ENCODING_16M		6
495 #define _PAGE_SIZE_ENCODING_64M		7
496 
497 #if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
498 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_4K
499 #elif defined(CONFIG_PARISC_PAGE_SIZE_16KB)
500 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_16K
501 #elif defined(CONFIG_PARISC_PAGE_SIZE_64KB)
502 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_64K
503 #endif
504 
505 
506 #define pgprot_noncached(prot) __pgprot(pgprot_val(prot) | _PAGE_NO_CACHE)
507 
508 /* We provide our own get_unmapped_area to provide cache coherency */
509 
510 #define HAVE_ARCH_UNMAPPED_AREA
511 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
512 
513 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
514 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
515 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
516 #define __HAVE_ARCH_PTE_SAME
517 
518 #endif /* _PARISC_PGTABLE_H */
519