xref: /linux/arch/parisc/include/asm/pgtable.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 #ifndef _PARISC_PGTABLE_H
2 #define _PARISC_PGTABLE_H
3 
4 #include <asm-generic/4level-fixup.h>
5 
6 #include <asm/fixmap.h>
7 
8 #ifndef __ASSEMBLY__
9 /*
10  * we simulate an x86-style page table for the linux mm code
11  */
12 
13 #include <linux/bitops.h>
14 #include <linux/spinlock.h>
15 #include <linux/mm_types.h>
16 #include <asm/processor.h>
17 #include <asm/cache.h>
18 
19 extern spinlock_t pa_tlb_lock;
20 
21 /*
22  * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
23  * memory.  For the return value to be meaningful, ADDR must be >=
24  * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
25  * require a hash-, or multi-level tree-lookup or something of that
26  * sort) but it guarantees to return TRUE only if accessing the page
27  * at that address does not cause an error.  Note that there may be
28  * addresses for which kern_addr_valid() returns FALSE even though an
29  * access would not cause an error (e.g., this is typically true for
30  * memory mapped I/O regions.
31  *
32  * XXX Need to implement this for parisc.
33  */
34 #define kern_addr_valid(addr)	(1)
35 
36 /* Purge data and instruction TLB entries.  Must be called holding
37  * the pa_tlb_lock.  The TLB purge instructions are slow on SMP
38  * machines since the purge must be broadcast to all CPUs.
39  */
40 
41 static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
42 {
43 	mtsp(mm->context, 1);
44 	pdtlb(addr);
45 	if (unlikely(split_tlb))
46 		pitlb(addr);
47 }
48 
49 /* Certain architectures need to do special things when PTEs
50  * within a page table are directly modified.  Thus, the following
51  * hook is made available.
52  */
53 #define set_pte(pteptr, pteval)                                 \
54         do{                                                     \
55                 *(pteptr) = (pteval);                           \
56         } while(0)
57 
58 #define pte_inserted(x)						\
59 	((pte_val(x) & (_PAGE_PRESENT|_PAGE_ACCESSED))		\
60 	 == (_PAGE_PRESENT|_PAGE_ACCESSED))
61 
62 #define set_pte_at(mm, addr, ptep, pteval)			\
63 	do {							\
64 		pte_t old_pte;					\
65 		unsigned long flags;				\
66 		spin_lock_irqsave(&pa_tlb_lock, flags);		\
67 		old_pte = *ptep;				\
68 		set_pte(ptep, pteval);				\
69 		if (pte_inserted(old_pte))			\
70 			purge_tlb_entries(mm, addr);		\
71 		spin_unlock_irqrestore(&pa_tlb_lock, flags);	\
72 	} while (0)
73 
74 #endif /* !__ASSEMBLY__ */
75 
76 #include <asm/page.h>
77 
78 #define pte_ERROR(e) \
79 	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
80 #define pmd_ERROR(e) \
81 	printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, (unsigned long)pmd_val(e))
82 #define pgd_ERROR(e) \
83 	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, (unsigned long)pgd_val(e))
84 
85 /* This is the size of the initially mapped kernel memory */
86 #define KERNEL_INITIAL_ORDER	24	/* 0 to 1<<24 = 16MB */
87 #define KERNEL_INITIAL_SIZE	(1 << KERNEL_INITIAL_ORDER)
88 
89 #if CONFIG_PGTABLE_LEVELS == 3
90 #define PGD_ORDER	1 /* Number of pages per pgd */
91 #define PMD_ORDER	1 /* Number of pages per pmd */
92 #define PGD_ALLOC_ORDER	2 /* first pgd contains pmd */
93 #else
94 #define PGD_ORDER	1 /* Number of pages per pgd */
95 #define PGD_ALLOC_ORDER	PGD_ORDER
96 #endif
97 
98 /* Definitions for 3rd level (we use PLD here for Page Lower directory
99  * because PTE_SHIFT is used lower down to mean shift that has to be
100  * done to get usable bits out of the PTE) */
101 #define PLD_SHIFT	PAGE_SHIFT
102 #define PLD_SIZE	PAGE_SIZE
103 #define BITS_PER_PTE	(PAGE_SHIFT - BITS_PER_PTE_ENTRY)
104 #define PTRS_PER_PTE    (1UL << BITS_PER_PTE)
105 
106 /* Definitions for 2nd level */
107 #define pgtable_cache_init()	do { } while (0)
108 
109 #define PMD_SHIFT       (PLD_SHIFT + BITS_PER_PTE)
110 #define PMD_SIZE	(1UL << PMD_SHIFT)
111 #define PMD_MASK	(~(PMD_SIZE-1))
112 #if CONFIG_PGTABLE_LEVELS == 3
113 #define BITS_PER_PMD	(PAGE_SHIFT + PMD_ORDER - BITS_PER_PMD_ENTRY)
114 #else
115 #define __PAGETABLE_PMD_FOLDED
116 #define BITS_PER_PMD	0
117 #endif
118 #define PTRS_PER_PMD    (1UL << BITS_PER_PMD)
119 
120 /* Definitions for 1st level */
121 #define PGDIR_SHIFT	(PMD_SHIFT + BITS_PER_PMD)
122 #if (PGDIR_SHIFT + PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY) > BITS_PER_LONG
123 #define BITS_PER_PGD	(BITS_PER_LONG - PGDIR_SHIFT)
124 #else
125 #define BITS_PER_PGD	(PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY)
126 #endif
127 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
128 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
129 #define PTRS_PER_PGD    (1UL << BITS_PER_PGD)
130 #define USER_PTRS_PER_PGD       PTRS_PER_PGD
131 
132 #ifdef CONFIG_64BIT
133 #define MAX_ADDRBITS	(PGDIR_SHIFT + BITS_PER_PGD)
134 #define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
135 #define SPACEID_SHIFT	(MAX_ADDRBITS - 32)
136 #else
137 #define MAX_ADDRBITS	(BITS_PER_LONG)
138 #define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
139 #define SPACEID_SHIFT	0
140 #endif
141 
142 /* This calculates the number of initial pages we need for the initial
143  * page tables */
144 #if (KERNEL_INITIAL_ORDER) >= (PMD_SHIFT)
145 # define PT_INITIAL	(1 << (KERNEL_INITIAL_ORDER - PMD_SHIFT))
146 #else
147 # define PT_INITIAL	(1)  /* all initial PTEs fit into one page */
148 #endif
149 
150 /*
151  * pgd entries used up by user/kernel:
152  */
153 
154 #define FIRST_USER_ADDRESS	0UL
155 
156 /* NB: The tlb miss handlers make certain assumptions about the order */
157 /*     of the following bits, so be careful (One example, bits 25-31  */
158 /*     are moved together in one instruction).                        */
159 
160 #define _PAGE_READ_BIT     31   /* (0x001) read access allowed */
161 #define _PAGE_WRITE_BIT    30   /* (0x002) write access allowed */
162 #define _PAGE_EXEC_BIT     29   /* (0x004) execute access allowed */
163 #define _PAGE_GATEWAY_BIT  28   /* (0x008) privilege promotion allowed */
164 #define _PAGE_DMB_BIT      27   /* (0x010) Data Memory Break enable (B bit) */
165 #define _PAGE_DIRTY_BIT    26   /* (0x020) Page Dirty (D bit) */
166 #define _PAGE_REFTRAP_BIT  25   /* (0x040) Page Ref. Trap enable (T bit) */
167 #define _PAGE_NO_CACHE_BIT 24   /* (0x080) Uncached Page (U bit) */
168 #define _PAGE_ACCESSED_BIT 23   /* (0x100) Software: Page Accessed */
169 #define _PAGE_PRESENT_BIT  22   /* (0x200) Software: translation valid */
170 /* bit 21 was formerly the FLUSH bit but is now unused */
171 #define _PAGE_USER_BIT     20   /* (0x800) Software: User accessible page */
172 
173 /* N.B. The bits are defined in terms of a 32 bit word above, so the */
174 /*      following macro is ok for both 32 and 64 bit.                */
175 
176 #define xlate_pabit(x) (31 - x)
177 
178 /* this defines the shift to the usable bits in the PTE it is set so
179  * that the valid bits _PAGE_PRESENT_BIT and _PAGE_USER_BIT are set
180  * to zero */
181 #define PTE_SHIFT	   	xlate_pabit(_PAGE_USER_BIT)
182 
183 /* PFN_PTE_SHIFT defines the shift of a PTE value to access the PFN field */
184 #define PFN_PTE_SHIFT		12
185 
186 #define _PAGE_READ     (1 << xlate_pabit(_PAGE_READ_BIT))
187 #define _PAGE_WRITE    (1 << xlate_pabit(_PAGE_WRITE_BIT))
188 #define _PAGE_RW       (_PAGE_READ | _PAGE_WRITE)
189 #define _PAGE_EXEC     (1 << xlate_pabit(_PAGE_EXEC_BIT))
190 #define _PAGE_GATEWAY  (1 << xlate_pabit(_PAGE_GATEWAY_BIT))
191 #define _PAGE_DMB      (1 << xlate_pabit(_PAGE_DMB_BIT))
192 #define _PAGE_DIRTY    (1 << xlate_pabit(_PAGE_DIRTY_BIT))
193 #define _PAGE_REFTRAP  (1 << xlate_pabit(_PAGE_REFTRAP_BIT))
194 #define _PAGE_NO_CACHE (1 << xlate_pabit(_PAGE_NO_CACHE_BIT))
195 #define _PAGE_ACCESSED (1 << xlate_pabit(_PAGE_ACCESSED_BIT))
196 #define _PAGE_PRESENT  (1 << xlate_pabit(_PAGE_PRESENT_BIT))
197 #define _PAGE_USER     (1 << xlate_pabit(_PAGE_USER_BIT))
198 
199 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE |  _PAGE_DIRTY | _PAGE_ACCESSED)
200 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
201 #define _PAGE_KERNEL_RO	(_PAGE_PRESENT | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED)
202 #define _PAGE_KERNEL_EXEC	(_PAGE_KERNEL_RO | _PAGE_EXEC)
203 #define _PAGE_KERNEL_RWX	(_PAGE_KERNEL_EXEC | _PAGE_WRITE)
204 #define _PAGE_KERNEL		(_PAGE_KERNEL_RO | _PAGE_WRITE)
205 
206 /* The pgd/pmd contains a ptr (in phys addr space); since all pgds/pmds
207  * are page-aligned, we don't care about the PAGE_OFFSET bits, except
208  * for a few meta-information bits, so we shift the address to be
209  * able to effectively address 40/42/44-bits of physical address space
210  * depending on 4k/16k/64k PAGE_SIZE */
211 #define _PxD_PRESENT_BIT   31
212 #define _PxD_ATTACHED_BIT  30
213 #define _PxD_VALID_BIT     29
214 
215 #define PxD_FLAG_PRESENT  (1 << xlate_pabit(_PxD_PRESENT_BIT))
216 #define PxD_FLAG_ATTACHED (1 << xlate_pabit(_PxD_ATTACHED_BIT))
217 #define PxD_FLAG_VALID    (1 << xlate_pabit(_PxD_VALID_BIT))
218 #define PxD_FLAG_MASK     (0xf)
219 #define PxD_FLAG_SHIFT    (4)
220 #define PxD_VALUE_SHIFT   (8) /* (PAGE_SHIFT-PxD_FLAG_SHIFT) */
221 
222 #ifndef __ASSEMBLY__
223 
224 #define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
225 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_ACCESSED)
226 /* Others seem to make this executable, I don't know if that's correct
227    or not.  The stack is mapped this way though so this is necessary
228    in the short term - dhd@linuxcare.com, 2000-08-08 */
229 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_ACCESSED)
230 #define PAGE_WRITEONLY  __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITE | _PAGE_ACCESSED)
231 #define PAGE_EXECREAD   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_EXEC |_PAGE_ACCESSED)
232 #define PAGE_COPY       PAGE_EXECREAD
233 #define PAGE_RWX        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC |_PAGE_ACCESSED)
234 #define PAGE_KERNEL	__pgprot(_PAGE_KERNEL)
235 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL_EXEC)
236 #define PAGE_KERNEL_RWX	__pgprot(_PAGE_KERNEL_RWX)
237 #define PAGE_KERNEL_RO	__pgprot(_PAGE_KERNEL_RO)
238 #define PAGE_KERNEL_UNC	__pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
239 #define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_GATEWAY| _PAGE_READ)
240 
241 
242 /*
243  * We could have an execute only page using "gateway - promote to priv
244  * level 3", but that is kind of silly. So, the way things are defined
245  * now, we must always have read permission for pages with execute
246  * permission. For the fun of it we'll go ahead and support write only
247  * pages.
248  */
249 
250 	 /*xwr*/
251 #define __P000  PAGE_NONE
252 #define __P001  PAGE_READONLY
253 #define __P010  __P000 /* copy on write */
254 #define __P011  __P001 /* copy on write */
255 #define __P100  PAGE_EXECREAD
256 #define __P101  PAGE_EXECREAD
257 #define __P110  __P100 /* copy on write */
258 #define __P111  __P101 /* copy on write */
259 
260 #define __S000  PAGE_NONE
261 #define __S001  PAGE_READONLY
262 #define __S010  PAGE_WRITEONLY
263 #define __S011  PAGE_SHARED
264 #define __S100  PAGE_EXECREAD
265 #define __S101  PAGE_EXECREAD
266 #define __S110  PAGE_RWX
267 #define __S111  PAGE_RWX
268 
269 
270 extern pgd_t swapper_pg_dir[]; /* declared in init_task.c */
271 
272 /* initial page tables for 0-8MB for kernel */
273 
274 extern pte_t pg0[];
275 
276 /* zero page used for uninitialized stuff */
277 
278 extern unsigned long *empty_zero_page;
279 
280 /*
281  * ZERO_PAGE is a global shared page that is always zero: used
282  * for zero-mapped memory areas etc..
283  */
284 
285 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
286 
287 #define pte_none(x)     (pte_val(x) == 0)
288 #define pte_present(x)	(pte_val(x) & _PAGE_PRESENT)
289 #define pte_clear(mm, addr, xp)  set_pte_at(mm, addr, xp, __pte(0))
290 
291 #define pmd_flag(x)	(pmd_val(x) & PxD_FLAG_MASK)
292 #define pmd_address(x)	((unsigned long)(pmd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
293 #define pgd_flag(x)	(pgd_val(x) & PxD_FLAG_MASK)
294 #define pgd_address(x)	((unsigned long)(pgd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
295 
296 #if CONFIG_PGTABLE_LEVELS == 3
297 /* The first entry of the permanent pmd is not there if it contains
298  * the gateway marker */
299 #define pmd_none(x)	(!pmd_val(x) || pmd_flag(x) == PxD_FLAG_ATTACHED)
300 #else
301 #define pmd_none(x)	(!pmd_val(x))
302 #endif
303 #define pmd_bad(x)	(!(pmd_flag(x) & PxD_FLAG_VALID))
304 #define pmd_present(x)	(pmd_flag(x) & PxD_FLAG_PRESENT)
305 static inline void pmd_clear(pmd_t *pmd) {
306 #if CONFIG_PGTABLE_LEVELS == 3
307 	if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
308 		/* This is the entry pointing to the permanent pmd
309 		 * attached to the pgd; cannot clear it */
310 		__pmd_val_set(*pmd, PxD_FLAG_ATTACHED);
311 	else
312 #endif
313 		__pmd_val_set(*pmd,  0);
314 }
315 
316 
317 
318 #if CONFIG_PGTABLE_LEVELS == 3
319 #define pgd_page_vaddr(pgd) ((unsigned long) __va(pgd_address(pgd)))
320 #define pgd_page(pgd)	virt_to_page((void *)pgd_page_vaddr(pgd))
321 
322 /* For 64 bit we have three level tables */
323 
324 #define pgd_none(x)     (!pgd_val(x))
325 #define pgd_bad(x)      (!(pgd_flag(x) & PxD_FLAG_VALID))
326 #define pgd_present(x)  (pgd_flag(x) & PxD_FLAG_PRESENT)
327 static inline void pgd_clear(pgd_t *pgd) {
328 #if CONFIG_PGTABLE_LEVELS == 3
329 	if(pgd_flag(*pgd) & PxD_FLAG_ATTACHED)
330 		/* This is the permanent pmd attached to the pgd; cannot
331 		 * free it */
332 		return;
333 #endif
334 	__pgd_val_set(*pgd, 0);
335 }
336 #else
337 /*
338  * The "pgd_xxx()" functions here are trivial for a folded two-level
339  * setup: the pgd is never bad, and a pmd always exists (as it's folded
340  * into the pgd entry)
341  */
342 static inline int pgd_none(pgd_t pgd)		{ return 0; }
343 static inline int pgd_bad(pgd_t pgd)		{ return 0; }
344 static inline int pgd_present(pgd_t pgd)	{ return 1; }
345 static inline void pgd_clear(pgd_t * pgdp)	{ }
346 #endif
347 
348 /*
349  * The following only work if pte_present() is true.
350  * Undefined behaviour if not..
351  */
352 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
353 static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
354 static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_WRITE; }
355 static inline int pte_special(pte_t pte)	{ return 0; }
356 
357 static inline pte_t pte_mkclean(pte_t pte)	{ pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
358 static inline pte_t pte_mkold(pte_t pte)	{ pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
359 static inline pte_t pte_wrprotect(pte_t pte)	{ pte_val(pte) &= ~_PAGE_WRITE; return pte; }
360 static inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= _PAGE_DIRTY; return pte; }
361 static inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= _PAGE_ACCESSED; return pte; }
362 static inline pte_t pte_mkwrite(pte_t pte)	{ pte_val(pte) |= _PAGE_WRITE; return pte; }
363 static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
364 
365 /*
366  * Conversion functions: convert a page and protection to a page entry,
367  * and a page entry and page directory to the page they refer to.
368  */
369 #define __mk_pte(addr,pgprot) \
370 ({									\
371 	pte_t __pte;							\
372 									\
373 	pte_val(__pte) = ((((addr)>>PAGE_SHIFT)<<PFN_PTE_SHIFT) + pgprot_val(pgprot));	\
374 									\
375 	__pte;								\
376 })
377 
378 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
379 
380 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
381 {
382 	pte_t pte;
383 	pte_val(pte) = (pfn << PFN_PTE_SHIFT) | pgprot_val(pgprot);
384 	return pte;
385 }
386 
387 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
388 { pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
389 
390 /* Permanent address of a page.  On parisc we don't have highmem. */
391 
392 #define pte_pfn(x)		(pte_val(x) >> PFN_PTE_SHIFT)
393 
394 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
395 
396 #define pmd_page_vaddr(pmd)	((unsigned long) __va(pmd_address(pmd)))
397 
398 #define __pmd_page(pmd) ((unsigned long) __va(pmd_address(pmd)))
399 #define pmd_page(pmd)	virt_to_page((void *)__pmd_page(pmd))
400 
401 #define pgd_index(address) ((address) >> PGDIR_SHIFT)
402 
403 /* to find an entry in a page-table-directory */
404 #define pgd_offset(mm, address) \
405 ((mm)->pgd + ((address) >> PGDIR_SHIFT))
406 
407 /* to find an entry in a kernel page-table-directory */
408 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
409 
410 /* Find an entry in the second-level page table.. */
411 
412 #if CONFIG_PGTABLE_LEVELS == 3
413 #define pmd_offset(dir,address) \
414 ((pmd_t *) pgd_page_vaddr(*(dir)) + (((address)>>PMD_SHIFT) & (PTRS_PER_PMD-1)))
415 #else
416 #define pmd_offset(dir,addr) ((pmd_t *) dir)
417 #endif
418 
419 /* Find an entry in the third-level page table.. */
420 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
421 #define pte_offset_kernel(pmd, address) \
422 	((pte_t *) pmd_page_vaddr(*(pmd)) + pte_index(address))
423 #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
424 #define pte_unmap(pte) do { } while (0)
425 
426 #define pte_unmap(pte)			do { } while (0)
427 #define pte_unmap_nested(pte)		do { } while (0)
428 
429 extern void paging_init (void);
430 
431 /* Used for deferring calls to flush_dcache_page() */
432 
433 #define PG_dcache_dirty         PG_arch_1
434 
435 extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t *);
436 
437 /* Encode and de-code a swap entry */
438 
439 #define __swp_type(x)                     ((x).val & 0x1f)
440 #define __swp_offset(x)                   ( (((x).val >> 6) &  0x7) | \
441 					  (((x).val >> 8) & ~0x7) )
442 #define __swp_entry(type, offset)         ((swp_entry_t) { (type) | \
443 					    ((offset &  0x7) << 6) | \
444 					    ((offset & ~0x7) << 8) })
445 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
446 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
447 
448 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
449 {
450 	pte_t pte;
451 	unsigned long flags;
452 
453 	if (!pte_young(*ptep))
454 		return 0;
455 
456 	spin_lock_irqsave(&pa_tlb_lock, flags);
457 	pte = *ptep;
458 	if (!pte_young(pte)) {
459 		spin_unlock_irqrestore(&pa_tlb_lock, flags);
460 		return 0;
461 	}
462 	set_pte(ptep, pte_mkold(pte));
463 	purge_tlb_entries(vma->vm_mm, addr);
464 	spin_unlock_irqrestore(&pa_tlb_lock, flags);
465 	return 1;
466 }
467 
468 struct mm_struct;
469 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
470 {
471 	pte_t old_pte;
472 	unsigned long flags;
473 
474 	spin_lock_irqsave(&pa_tlb_lock, flags);
475 	old_pte = *ptep;
476 	set_pte(ptep, __pte(0));
477 	if (pte_inserted(old_pte))
478 		purge_tlb_entries(mm, addr);
479 	spin_unlock_irqrestore(&pa_tlb_lock, flags);
480 
481 	return old_pte;
482 }
483 
484 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
485 {
486 	unsigned long flags;
487 	spin_lock_irqsave(&pa_tlb_lock, flags);
488 	set_pte(ptep, pte_wrprotect(*ptep));
489 	purge_tlb_entries(mm, addr);
490 	spin_unlock_irqrestore(&pa_tlb_lock, flags);
491 }
492 
493 #define pte_same(A,B)	(pte_val(A) == pte_val(B))
494 
495 #endif /* !__ASSEMBLY__ */
496 
497 
498 /* TLB page size encoding - see table 3-1 in parisc20.pdf */
499 #define _PAGE_SIZE_ENCODING_4K		0
500 #define _PAGE_SIZE_ENCODING_16K		1
501 #define _PAGE_SIZE_ENCODING_64K		2
502 #define _PAGE_SIZE_ENCODING_256K	3
503 #define _PAGE_SIZE_ENCODING_1M		4
504 #define _PAGE_SIZE_ENCODING_4M		5
505 #define _PAGE_SIZE_ENCODING_16M		6
506 #define _PAGE_SIZE_ENCODING_64M		7
507 
508 #if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
509 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_4K
510 #elif defined(CONFIG_PARISC_PAGE_SIZE_16KB)
511 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_16K
512 #elif defined(CONFIG_PARISC_PAGE_SIZE_64KB)
513 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_64K
514 #endif
515 
516 
517 #define pgprot_noncached(prot) __pgprot(pgprot_val(prot) | _PAGE_NO_CACHE)
518 
519 /* We provide our own get_unmapped_area to provide cache coherency */
520 
521 #define HAVE_ARCH_UNMAPPED_AREA
522 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
523 
524 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
525 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
526 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
527 #define __HAVE_ARCH_PTE_SAME
528 #include <asm-generic/pgtable.h>
529 
530 #endif /* _PARISC_PGTABLE_H */
531