xref: /openbmc/linux/arch/parisc/include/asm/pgtable.h (revision 05bcf503)
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 <asm/processor.h>
16 #include <asm/cache.h>
17 
18 struct vm_area_struct;
19 
20 /*
21  * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
22  * memory.  For the return value to be meaningful, ADDR must be >=
23  * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
24  * require a hash-, or multi-level tree-lookup or something of that
25  * sort) but it guarantees to return TRUE only if accessing the page
26  * at that address does not cause an error.  Note that there may be
27  * addresses for which kern_addr_valid() returns FALSE even though an
28  * access would not cause an error (e.g., this is typically true for
29  * memory mapped I/O regions.
30  *
31  * XXX Need to implement this for parisc.
32  */
33 #define kern_addr_valid(addr)	(1)
34 
35 /* Certain architectures need to do special things when PTEs
36  * within a page table are directly modified.  Thus, the following
37  * hook is made available.
38  */
39 #define set_pte(pteptr, pteval)                                 \
40         do{                                                     \
41                 *(pteptr) = (pteval);                           \
42         } while(0)
43 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
44 
45 #endif /* !__ASSEMBLY__ */
46 
47 #include <asm/page.h>
48 
49 #define pte_ERROR(e) \
50 	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
51 #define pmd_ERROR(e) \
52 	printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, (unsigned long)pmd_val(e))
53 #define pgd_ERROR(e) \
54 	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, (unsigned long)pgd_val(e))
55 
56 /* This is the size of the initially mapped kernel memory */
57 #define KERNEL_INITIAL_ORDER	24	/* 0 to 1<<24 = 16MB */
58 #define KERNEL_INITIAL_SIZE	(1 << KERNEL_INITIAL_ORDER)
59 
60 #if defined(CONFIG_64BIT) && defined(CONFIG_PARISC_PAGE_SIZE_4KB)
61 #define PT_NLEVELS	3
62 #define PGD_ORDER	1 /* Number of pages per pgd */
63 #define PMD_ORDER	1 /* Number of pages per pmd */
64 #define PGD_ALLOC_ORDER	2 /* first pgd contains pmd */
65 #else
66 #define PT_NLEVELS	2
67 #define PGD_ORDER	1 /* Number of pages per pgd */
68 #define PGD_ALLOC_ORDER	PGD_ORDER
69 #endif
70 
71 /* Definitions for 3rd level (we use PLD here for Page Lower directory
72  * because PTE_SHIFT is used lower down to mean shift that has to be
73  * done to get usable bits out of the PTE) */
74 #define PLD_SHIFT	PAGE_SHIFT
75 #define PLD_SIZE	PAGE_SIZE
76 #define BITS_PER_PTE	(PAGE_SHIFT - BITS_PER_PTE_ENTRY)
77 #define PTRS_PER_PTE    (1UL << BITS_PER_PTE)
78 
79 /* Definitions for 2nd level */
80 #define pgtable_cache_init()	do { } while (0)
81 
82 #define PMD_SHIFT       (PLD_SHIFT + BITS_PER_PTE)
83 #define PMD_SIZE	(1UL << PMD_SHIFT)
84 #define PMD_MASK	(~(PMD_SIZE-1))
85 #if PT_NLEVELS == 3
86 #define BITS_PER_PMD	(PAGE_SHIFT + PMD_ORDER - BITS_PER_PMD_ENTRY)
87 #else
88 #define BITS_PER_PMD	0
89 #endif
90 #define PTRS_PER_PMD    (1UL << BITS_PER_PMD)
91 
92 /* Definitions for 1st level */
93 #define PGDIR_SHIFT	(PMD_SHIFT + BITS_PER_PMD)
94 #if (PGDIR_SHIFT + PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY) > BITS_PER_LONG
95 #define BITS_PER_PGD	(BITS_PER_LONG - PGDIR_SHIFT)
96 #else
97 #define BITS_PER_PGD	(PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY)
98 #endif
99 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
100 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
101 #define PTRS_PER_PGD    (1UL << BITS_PER_PGD)
102 #define USER_PTRS_PER_PGD       PTRS_PER_PGD
103 
104 #ifdef CONFIG_64BIT
105 #define MAX_ADDRBITS	(PGDIR_SHIFT + BITS_PER_PGD)
106 #define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
107 #define SPACEID_SHIFT	(MAX_ADDRBITS - 32)
108 #else
109 #define MAX_ADDRBITS	(BITS_PER_LONG)
110 #define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
111 #define SPACEID_SHIFT	0
112 #endif
113 
114 /* This calculates the number of initial pages we need for the initial
115  * page tables */
116 #if (KERNEL_INITIAL_ORDER) >= (PMD_SHIFT)
117 # define PT_INITIAL	(1 << (KERNEL_INITIAL_ORDER - PMD_SHIFT))
118 #else
119 # define PT_INITIAL	(1)  /* all initial PTEs fit into one page */
120 #endif
121 
122 /*
123  * pgd entries used up by user/kernel:
124  */
125 
126 #define FIRST_USER_ADDRESS	0
127 
128 /* NB: The tlb miss handlers make certain assumptions about the order */
129 /*     of the following bits, so be careful (One example, bits 25-31  */
130 /*     are moved together in one instruction).                        */
131 
132 #define _PAGE_READ_BIT     31   /* (0x001) read access allowed */
133 #define _PAGE_WRITE_BIT    30   /* (0x002) write access allowed */
134 #define _PAGE_EXEC_BIT     29   /* (0x004) execute access allowed */
135 #define _PAGE_GATEWAY_BIT  28   /* (0x008) privilege promotion allowed */
136 #define _PAGE_DMB_BIT      27   /* (0x010) Data Memory Break enable (B bit) */
137 #define _PAGE_DIRTY_BIT    26   /* (0x020) Page Dirty (D bit) */
138 #define _PAGE_FILE_BIT	_PAGE_DIRTY_BIT	/* overload this bit */
139 #define _PAGE_REFTRAP_BIT  25   /* (0x040) Page Ref. Trap enable (T bit) */
140 #define _PAGE_NO_CACHE_BIT 24   /* (0x080) Uncached Page (U bit) */
141 #define _PAGE_ACCESSED_BIT 23   /* (0x100) Software: Page Accessed */
142 #define _PAGE_PRESENT_BIT  22   /* (0x200) Software: translation valid */
143 /* bit 21 was formerly the FLUSH bit but is now unused */
144 #define _PAGE_USER_BIT     20   /* (0x800) Software: User accessible page */
145 
146 /* N.B. The bits are defined in terms of a 32 bit word above, so the */
147 /*      following macro is ok for both 32 and 64 bit.                */
148 
149 #define xlate_pabit(x) (31 - x)
150 
151 /* this defines the shift to the usable bits in the PTE it is set so
152  * that the valid bits _PAGE_PRESENT_BIT and _PAGE_USER_BIT are set
153  * to zero */
154 #define PTE_SHIFT	   	xlate_pabit(_PAGE_USER_BIT)
155 
156 /* PFN_PTE_SHIFT defines the shift of a PTE value to access the PFN field */
157 #define PFN_PTE_SHIFT		12
158 
159 
160 /* this is how many bits may be used by the file functions */
161 #define PTE_FILE_MAX_BITS	(BITS_PER_LONG - PTE_SHIFT)
162 
163 #define pte_to_pgoff(pte) (pte_val(pte) >> PTE_SHIFT)
164 #define pgoff_to_pte(off) ((pte_t) { ((off) << PTE_SHIFT) | _PAGE_FILE })
165 
166 #define _PAGE_READ     (1 << xlate_pabit(_PAGE_READ_BIT))
167 #define _PAGE_WRITE    (1 << xlate_pabit(_PAGE_WRITE_BIT))
168 #define _PAGE_RW       (_PAGE_READ | _PAGE_WRITE)
169 #define _PAGE_EXEC     (1 << xlate_pabit(_PAGE_EXEC_BIT))
170 #define _PAGE_GATEWAY  (1 << xlate_pabit(_PAGE_GATEWAY_BIT))
171 #define _PAGE_DMB      (1 << xlate_pabit(_PAGE_DMB_BIT))
172 #define _PAGE_DIRTY    (1 << xlate_pabit(_PAGE_DIRTY_BIT))
173 #define _PAGE_REFTRAP  (1 << xlate_pabit(_PAGE_REFTRAP_BIT))
174 #define _PAGE_NO_CACHE (1 << xlate_pabit(_PAGE_NO_CACHE_BIT))
175 #define _PAGE_ACCESSED (1 << xlate_pabit(_PAGE_ACCESSED_BIT))
176 #define _PAGE_PRESENT  (1 << xlate_pabit(_PAGE_PRESENT_BIT))
177 #define _PAGE_USER     (1 << xlate_pabit(_PAGE_USER_BIT))
178 #define _PAGE_FILE     (1 << xlate_pabit(_PAGE_FILE_BIT))
179 
180 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE |  _PAGE_DIRTY | _PAGE_ACCESSED)
181 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
182 #define _PAGE_KERNEL_RO	(_PAGE_PRESENT | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED)
183 #define _PAGE_KERNEL_EXEC	(_PAGE_KERNEL_RO | _PAGE_EXEC)
184 #define _PAGE_KERNEL_RWX	(_PAGE_KERNEL_EXEC | _PAGE_WRITE)
185 #define _PAGE_KERNEL		(_PAGE_KERNEL_RO | _PAGE_WRITE)
186 
187 /* The pgd/pmd contains a ptr (in phys addr space); since all pgds/pmds
188  * are page-aligned, we don't care about the PAGE_OFFSET bits, except
189  * for a few meta-information bits, so we shift the address to be
190  * able to effectively address 40/42/44-bits of physical address space
191  * depending on 4k/16k/64k PAGE_SIZE */
192 #define _PxD_PRESENT_BIT   31
193 #define _PxD_ATTACHED_BIT  30
194 #define _PxD_VALID_BIT     29
195 
196 #define PxD_FLAG_PRESENT  (1 << xlate_pabit(_PxD_PRESENT_BIT))
197 #define PxD_FLAG_ATTACHED (1 << xlate_pabit(_PxD_ATTACHED_BIT))
198 #define PxD_FLAG_VALID    (1 << xlate_pabit(_PxD_VALID_BIT))
199 #define PxD_FLAG_MASK     (0xf)
200 #define PxD_FLAG_SHIFT    (4)
201 #define PxD_VALUE_SHIFT   (8) /* (PAGE_SHIFT-PxD_FLAG_SHIFT) */
202 
203 #ifndef __ASSEMBLY__
204 
205 #define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
206 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_ACCESSED)
207 /* Others seem to make this executable, I don't know if that's correct
208    or not.  The stack is mapped this way though so this is necessary
209    in the short term - dhd@linuxcare.com, 2000-08-08 */
210 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_ACCESSED)
211 #define PAGE_WRITEONLY  __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITE | _PAGE_ACCESSED)
212 #define PAGE_EXECREAD   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_EXEC |_PAGE_ACCESSED)
213 #define PAGE_COPY       PAGE_EXECREAD
214 #define PAGE_RWX        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC |_PAGE_ACCESSED)
215 #define PAGE_KERNEL	__pgprot(_PAGE_KERNEL)
216 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL_EXEC)
217 #define PAGE_KERNEL_RWX	__pgprot(_PAGE_KERNEL_RWX)
218 #define PAGE_KERNEL_RO	__pgprot(_PAGE_KERNEL_RO)
219 #define PAGE_KERNEL_UNC	__pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
220 #define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_GATEWAY| _PAGE_READ)
221 
222 
223 /*
224  * We could have an execute only page using "gateway - promote to priv
225  * level 3", but that is kind of silly. So, the way things are defined
226  * now, we must always have read permission for pages with execute
227  * permission. For the fun of it we'll go ahead and support write only
228  * pages.
229  */
230 
231 	 /*xwr*/
232 #define __P000  PAGE_NONE
233 #define __P001  PAGE_READONLY
234 #define __P010  __P000 /* copy on write */
235 #define __P011  __P001 /* copy on write */
236 #define __P100  PAGE_EXECREAD
237 #define __P101  PAGE_EXECREAD
238 #define __P110  __P100 /* copy on write */
239 #define __P111  __P101 /* copy on write */
240 
241 #define __S000  PAGE_NONE
242 #define __S001  PAGE_READONLY
243 #define __S010  PAGE_WRITEONLY
244 #define __S011  PAGE_SHARED
245 #define __S100  PAGE_EXECREAD
246 #define __S101  PAGE_EXECREAD
247 #define __S110  PAGE_RWX
248 #define __S111  PAGE_RWX
249 
250 
251 extern pgd_t swapper_pg_dir[]; /* declared in init_task.c */
252 
253 /* initial page tables for 0-8MB for kernel */
254 
255 extern pte_t pg0[];
256 
257 /* zero page used for uninitialized stuff */
258 
259 extern unsigned long *empty_zero_page;
260 
261 /*
262  * ZERO_PAGE is a global shared page that is always zero: used
263  * for zero-mapped memory areas etc..
264  */
265 
266 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
267 
268 #define pte_none(x)     (pte_val(x) == 0)
269 #define pte_present(x)	(pte_val(x) & _PAGE_PRESENT)
270 #define pte_clear(mm,addr,xp)	do { pte_val(*(xp)) = 0; } while (0)
271 
272 #define pmd_flag(x)	(pmd_val(x) & PxD_FLAG_MASK)
273 #define pmd_address(x)	((unsigned long)(pmd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
274 #define pgd_flag(x)	(pgd_val(x) & PxD_FLAG_MASK)
275 #define pgd_address(x)	((unsigned long)(pgd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
276 
277 #if PT_NLEVELS == 3
278 /* The first entry of the permanent pmd is not there if it contains
279  * the gateway marker */
280 #define pmd_none(x)	(!pmd_val(x) || pmd_flag(x) == PxD_FLAG_ATTACHED)
281 #else
282 #define pmd_none(x)	(!pmd_val(x))
283 #endif
284 #define pmd_bad(x)	(!(pmd_flag(x) & PxD_FLAG_VALID))
285 #define pmd_present(x)	(pmd_flag(x) & PxD_FLAG_PRESENT)
286 static inline void pmd_clear(pmd_t *pmd) {
287 #if PT_NLEVELS == 3
288 	if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
289 		/* This is the entry pointing to the permanent pmd
290 		 * attached to the pgd; cannot clear it */
291 		__pmd_val_set(*pmd, PxD_FLAG_ATTACHED);
292 	else
293 #endif
294 		__pmd_val_set(*pmd,  0);
295 }
296 
297 
298 
299 #if PT_NLEVELS == 3
300 #define pgd_page_vaddr(pgd) ((unsigned long) __va(pgd_address(pgd)))
301 #define pgd_page(pgd)	virt_to_page((void *)pgd_page_vaddr(pgd))
302 
303 /* For 64 bit we have three level tables */
304 
305 #define pgd_none(x)     (!pgd_val(x))
306 #define pgd_bad(x)      (!(pgd_flag(x) & PxD_FLAG_VALID))
307 #define pgd_present(x)  (pgd_flag(x) & PxD_FLAG_PRESENT)
308 static inline void pgd_clear(pgd_t *pgd) {
309 #if PT_NLEVELS == 3
310 	if(pgd_flag(*pgd) & PxD_FLAG_ATTACHED)
311 		/* This is the permanent pmd attached to the pgd; cannot
312 		 * free it */
313 		return;
314 #endif
315 	__pgd_val_set(*pgd, 0);
316 }
317 #else
318 /*
319  * The "pgd_xxx()" functions here are trivial for a folded two-level
320  * setup: the pgd is never bad, and a pmd always exists (as it's folded
321  * into the pgd entry)
322  */
323 static inline int pgd_none(pgd_t pgd)		{ return 0; }
324 static inline int pgd_bad(pgd_t pgd)		{ return 0; }
325 static inline int pgd_present(pgd_t pgd)	{ return 1; }
326 static inline void pgd_clear(pgd_t * pgdp)	{ }
327 #endif
328 
329 /*
330  * The following only work if pte_present() is true.
331  * Undefined behaviour if not..
332  */
333 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
334 static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
335 static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_WRITE; }
336 static inline int pte_file(pte_t pte)		{ return pte_val(pte) & _PAGE_FILE; }
337 static inline int pte_special(pte_t pte)	{ return 0; }
338 
339 static inline pte_t pte_mkclean(pte_t pte)	{ pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
340 static inline pte_t pte_mkold(pte_t pte)	{ pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
341 static inline pte_t pte_wrprotect(pte_t pte)	{ pte_val(pte) &= ~_PAGE_WRITE; return pte; }
342 static inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= _PAGE_DIRTY; return pte; }
343 static inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= _PAGE_ACCESSED; return pte; }
344 static inline pte_t pte_mkwrite(pte_t pte)	{ pte_val(pte) |= _PAGE_WRITE; return pte; }
345 static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
346 
347 /*
348  * Conversion functions: convert a page and protection to a page entry,
349  * and a page entry and page directory to the page they refer to.
350  */
351 #define __mk_pte(addr,pgprot) \
352 ({									\
353 	pte_t __pte;							\
354 									\
355 	pte_val(__pte) = ((((addr)>>PAGE_SHIFT)<<PFN_PTE_SHIFT) + pgprot_val(pgprot));	\
356 									\
357 	__pte;								\
358 })
359 
360 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
361 
362 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
363 {
364 	pte_t pte;
365 	pte_val(pte) = (pfn << PFN_PTE_SHIFT) | pgprot_val(pgprot);
366 	return pte;
367 }
368 
369 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
370 { pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
371 
372 /* Permanent address of a page.  On parisc we don't have highmem. */
373 
374 #define pte_pfn(x)		(pte_val(x) >> PFN_PTE_SHIFT)
375 
376 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
377 
378 #define pmd_page_vaddr(pmd)	((unsigned long) __va(pmd_address(pmd)))
379 
380 #define __pmd_page(pmd) ((unsigned long) __va(pmd_address(pmd)))
381 #define pmd_page(pmd)	virt_to_page((void *)__pmd_page(pmd))
382 
383 #define pgd_index(address) ((address) >> PGDIR_SHIFT)
384 
385 /* to find an entry in a page-table-directory */
386 #define pgd_offset(mm, address) \
387 ((mm)->pgd + ((address) >> PGDIR_SHIFT))
388 
389 /* to find an entry in a kernel page-table-directory */
390 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
391 
392 /* Find an entry in the second-level page table.. */
393 
394 #if PT_NLEVELS == 3
395 #define pmd_offset(dir,address) \
396 ((pmd_t *) pgd_page_vaddr(*(dir)) + (((address)>>PMD_SHIFT) & (PTRS_PER_PMD-1)))
397 #else
398 #define pmd_offset(dir,addr) ((pmd_t *) dir)
399 #endif
400 
401 /* Find an entry in the third-level page table.. */
402 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
403 #define pte_offset_kernel(pmd, address) \
404 	((pte_t *) pmd_page_vaddr(*(pmd)) + pte_index(address))
405 #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
406 #define pte_unmap(pte) do { } while (0)
407 
408 #define pte_unmap(pte)			do { } while (0)
409 #define pte_unmap_nested(pte)		do { } while (0)
410 
411 extern void paging_init (void);
412 
413 /* Used for deferring calls to flush_dcache_page() */
414 
415 #define PG_dcache_dirty         PG_arch_1
416 
417 extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t *);
418 
419 /* Encode and de-code a swap entry */
420 
421 #define __swp_type(x)                     ((x).val & 0x1f)
422 #define __swp_offset(x)                   ( (((x).val >> 6) &  0x7) | \
423 					  (((x).val >> 8) & ~0x7) )
424 #define __swp_entry(type, offset)         ((swp_entry_t) { (type) | \
425 					    ((offset &  0x7) << 6) | \
426 					    ((offset & ~0x7) << 8) })
427 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
428 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
429 
430 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
431 {
432 #ifdef CONFIG_SMP
433 	if (!pte_young(*ptep))
434 		return 0;
435 	return test_and_clear_bit(xlate_pabit(_PAGE_ACCESSED_BIT), &pte_val(*ptep));
436 #else
437 	pte_t pte = *ptep;
438 	if (!pte_young(pte))
439 		return 0;
440 	set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
441 	return 1;
442 #endif
443 }
444 
445 extern spinlock_t pa_dbit_lock;
446 
447 struct mm_struct;
448 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
449 {
450 	pte_t old_pte;
451 
452 	spin_lock(&pa_dbit_lock);
453 	old_pte = *ptep;
454 	pte_clear(mm,addr,ptep);
455 	spin_unlock(&pa_dbit_lock);
456 
457 	return old_pte;
458 }
459 
460 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
461 {
462 #ifdef CONFIG_SMP
463 	unsigned long new, old;
464 
465 	do {
466 		old = pte_val(*ptep);
467 		new = pte_val(pte_wrprotect(__pte (old)));
468 	} while (cmpxchg((unsigned long *) ptep, old, new) != old);
469 #else
470 	pte_t old_pte = *ptep;
471 	set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
472 #endif
473 }
474 
475 #define pte_same(A,B)	(pte_val(A) == pte_val(B))
476 
477 #endif /* !__ASSEMBLY__ */
478 
479 
480 /* TLB page size encoding - see table 3-1 in parisc20.pdf */
481 #define _PAGE_SIZE_ENCODING_4K		0
482 #define _PAGE_SIZE_ENCODING_16K		1
483 #define _PAGE_SIZE_ENCODING_64K		2
484 #define _PAGE_SIZE_ENCODING_256K	3
485 #define _PAGE_SIZE_ENCODING_1M		4
486 #define _PAGE_SIZE_ENCODING_4M		5
487 #define _PAGE_SIZE_ENCODING_16M		6
488 #define _PAGE_SIZE_ENCODING_64M		7
489 
490 #if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
491 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_4K
492 #elif defined(CONFIG_PARISC_PAGE_SIZE_16KB)
493 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_16K
494 #elif defined(CONFIG_PARISC_PAGE_SIZE_64KB)
495 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_64K
496 #endif
497 
498 
499 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
500 		remap_pfn_range(vma, vaddr, pfn, size, prot)
501 
502 #define pgprot_noncached(prot) __pgprot(pgprot_val(prot) | _PAGE_NO_CACHE)
503 
504 /* We provide our own get_unmapped_area to provide cache coherency */
505 
506 #define HAVE_ARCH_UNMAPPED_AREA
507 
508 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
509 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
510 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
511 #define __HAVE_ARCH_PTE_SAME
512 #include <asm-generic/pgtable.h>
513 
514 #endif /* _PARISC_PGTABLE_H */
515