xref: /linux/arch/parisc/include/asm/pgtable.h (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
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 static inline spinlock_t *pgd_spinlock(pgd_t *);
27 
28 /*
29  * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
30  * memory.  For the return value to be meaningful, ADDR must be >=
31  * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
32  * require a hash-, or multi-level tree-lookup or something of that
33  * sort) but it guarantees to return TRUE only if accessing the page
34  * at that address does not cause an error.  Note that there may be
35  * addresses for which kern_addr_valid() returns FALSE even though an
36  * access would not cause an error (e.g., this is typically true for
37  * memory mapped I/O regions.
38  *
39  * XXX Need to implement this for parisc.
40  */
41 #define kern_addr_valid(addr)	(1)
42 
43 /* This is for the serialization of PxTLB broadcasts. At least on the N class
44  * systems, only one PxTLB inter processor broadcast can be active at any one
45  * time on the Merced bus.
46 
47  * PTE updates are protected by locks in the PMD.
48  */
49 extern spinlock_t pa_tlb_flush_lock;
50 extern spinlock_t pa_swapper_pg_lock;
51 #if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
52 extern int pa_serialize_tlb_flushes;
53 #else
54 #define pa_serialize_tlb_flushes        (0)
55 #endif
56 
57 #define purge_tlb_start(flags)  do { \
58 	if (pa_serialize_tlb_flushes)	\
59 		spin_lock_irqsave(&pa_tlb_flush_lock, flags); \
60 	else \
61 		local_irq_save(flags);	\
62 	} while (0)
63 #define purge_tlb_end(flags)	do { \
64 	if (pa_serialize_tlb_flushes)	\
65 		spin_unlock_irqrestore(&pa_tlb_flush_lock, flags); \
66 	else \
67 		local_irq_restore(flags); \
68 	} while (0)
69 
70 /* Purge data and instruction TLB entries. The TLB purge instructions
71  * are slow on SMP machines since the purge must be broadcast to all CPUs.
72  */
73 
74 static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
75 {
76 	unsigned long flags;
77 
78 	purge_tlb_start(flags);
79 	mtsp(mm->context, 1);
80 	pdtlb(addr);
81 	pitlb(addr);
82 	purge_tlb_end(flags);
83 }
84 
85 /* Certain architectures need to do special things when PTEs
86  * within a page table are directly modified.  Thus, the following
87  * hook is made available.
88  */
89 #define set_pte(pteptr, pteval)                                 \
90         do{                                                     \
91                 *(pteptr) = (pteval);                           \
92         } while(0)
93 
94 #define set_pte_at(mm, addr, ptep, pteval)			\
95 	do {							\
96 		unsigned long flags;				\
97 		spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);\
98 		set_pte(ptep, pteval);				\
99 		purge_tlb_entries(mm, addr);			\
100 		spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);\
101 	} while (0)
102 
103 #endif /* !__ASSEMBLY__ */
104 
105 #define pte_ERROR(e) \
106 	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
107 #if CONFIG_PGTABLE_LEVELS == 3
108 #define pmd_ERROR(e) \
109 	printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, (unsigned long)pmd_val(e))
110 #endif
111 #define pgd_ERROR(e) \
112 	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, (unsigned long)pgd_val(e))
113 
114 /* This is the size of the initially mapped kernel memory */
115 #if defined(CONFIG_64BIT)
116 #define KERNEL_INITIAL_ORDER	26	/* 1<<26 = 64MB */
117 #else
118 #define KERNEL_INITIAL_ORDER	25	/* 1<<25 = 32MB */
119 #endif
120 #define KERNEL_INITIAL_SIZE	(1 << KERNEL_INITIAL_ORDER)
121 
122 #if CONFIG_PGTABLE_LEVELS == 3
123 #define PGD_ORDER	1 /* Number of pages per pgd */
124 #define PMD_ORDER	1 /* Number of pages per pmd */
125 #define PGD_ALLOC_ORDER	(2 + 1) /* first pgd contains pmd */
126 #else
127 #define PGD_ORDER	1 /* Number of pages per pgd */
128 #define PGD_ALLOC_ORDER	(PGD_ORDER + 1)
129 #endif
130 
131 /* Definitions for 3rd level (we use PLD here for Page Lower directory
132  * because PTE_SHIFT is used lower down to mean shift that has to be
133  * done to get usable bits out of the PTE) */
134 #define PLD_SHIFT	PAGE_SHIFT
135 #define PLD_SIZE	PAGE_SIZE
136 #define BITS_PER_PTE	(PAGE_SHIFT - BITS_PER_PTE_ENTRY)
137 #define PTRS_PER_PTE    (1UL << BITS_PER_PTE)
138 
139 /* Definitions for 2nd level */
140 #if CONFIG_PGTABLE_LEVELS == 3
141 #define PMD_SHIFT       (PLD_SHIFT + BITS_PER_PTE)
142 #define PMD_SIZE	(1UL << PMD_SHIFT)
143 #define PMD_MASK	(~(PMD_SIZE-1))
144 #define BITS_PER_PMD	(PAGE_SHIFT + PMD_ORDER - BITS_PER_PMD_ENTRY)
145 #define PTRS_PER_PMD    (1UL << BITS_PER_PMD)
146 #else
147 #define BITS_PER_PMD	0
148 #endif
149 
150 /* Definitions for 1st level */
151 #define PGDIR_SHIFT	(PLD_SHIFT + BITS_PER_PTE + BITS_PER_PMD)
152 #if (PGDIR_SHIFT + PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY) > BITS_PER_LONG
153 #define BITS_PER_PGD	(BITS_PER_LONG - PGDIR_SHIFT)
154 #else
155 #define BITS_PER_PGD	(PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY)
156 #endif
157 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
158 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
159 #define PTRS_PER_PGD    (1UL << BITS_PER_PGD)
160 #define USER_PTRS_PER_PGD       PTRS_PER_PGD
161 
162 #ifdef CONFIG_64BIT
163 #define MAX_ADDRBITS	(PGDIR_SHIFT + BITS_PER_PGD)
164 #define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
165 #define SPACEID_SHIFT	(MAX_ADDRBITS - 32)
166 #else
167 #define MAX_ADDRBITS	(BITS_PER_LONG)
168 #define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
169 #define SPACEID_SHIFT	0
170 #endif
171 
172 /* This calculates the number of initial pages we need for the initial
173  * page tables */
174 #if (KERNEL_INITIAL_ORDER) >= (PMD_SHIFT)
175 # define PT_INITIAL	(1 << (KERNEL_INITIAL_ORDER - PMD_SHIFT))
176 #else
177 # define PT_INITIAL	(1)  /* all initial PTEs fit into one page */
178 #endif
179 
180 /*
181  * pgd entries used up by user/kernel:
182  */
183 
184 #define FIRST_USER_ADDRESS	0UL
185 
186 /* NB: The tlb miss handlers make certain assumptions about the order */
187 /*     of the following bits, so be careful (One example, bits 25-31  */
188 /*     are moved together in one instruction).                        */
189 
190 #define _PAGE_READ_BIT     31   /* (0x001) read access allowed */
191 #define _PAGE_WRITE_BIT    30   /* (0x002) write access allowed */
192 #define _PAGE_EXEC_BIT     29   /* (0x004) execute access allowed */
193 #define _PAGE_GATEWAY_BIT  28   /* (0x008) privilege promotion allowed */
194 #define _PAGE_DMB_BIT      27   /* (0x010) Data Memory Break enable (B bit) */
195 #define _PAGE_DIRTY_BIT    26   /* (0x020) Page Dirty (D bit) */
196 #define _PAGE_REFTRAP_BIT  25   /* (0x040) Page Ref. Trap enable (T bit) */
197 #define _PAGE_NO_CACHE_BIT 24   /* (0x080) Uncached Page (U bit) */
198 #define _PAGE_ACCESSED_BIT 23   /* (0x100) Software: Page Accessed */
199 #define _PAGE_PRESENT_BIT  22   /* (0x200) Software: translation valid */
200 #define _PAGE_HPAGE_BIT    21   /* (0x400) Software: Huge Page */
201 #define _PAGE_USER_BIT     20   /* (0x800) Software: User accessible page */
202 
203 /* N.B. The bits are defined in terms of a 32 bit word above, so the */
204 /*      following macro is ok for both 32 and 64 bit.                */
205 
206 #define xlate_pabit(x) (31 - x)
207 
208 /* this defines the shift to the usable bits in the PTE it is set so
209  * that the valid bits _PAGE_PRESENT_BIT and _PAGE_USER_BIT are set
210  * to zero */
211 #define PTE_SHIFT	   	xlate_pabit(_PAGE_USER_BIT)
212 
213 /* PFN_PTE_SHIFT defines the shift of a PTE value to access the PFN field */
214 #define PFN_PTE_SHIFT		12
215 
216 #define _PAGE_READ     (1 << xlate_pabit(_PAGE_READ_BIT))
217 #define _PAGE_WRITE    (1 << xlate_pabit(_PAGE_WRITE_BIT))
218 #define _PAGE_RW       (_PAGE_READ | _PAGE_WRITE)
219 #define _PAGE_EXEC     (1 << xlate_pabit(_PAGE_EXEC_BIT))
220 #define _PAGE_GATEWAY  (1 << xlate_pabit(_PAGE_GATEWAY_BIT))
221 #define _PAGE_DMB      (1 << xlate_pabit(_PAGE_DMB_BIT))
222 #define _PAGE_DIRTY    (1 << xlate_pabit(_PAGE_DIRTY_BIT))
223 #define _PAGE_REFTRAP  (1 << xlate_pabit(_PAGE_REFTRAP_BIT))
224 #define _PAGE_NO_CACHE (1 << xlate_pabit(_PAGE_NO_CACHE_BIT))
225 #define _PAGE_ACCESSED (1 << xlate_pabit(_PAGE_ACCESSED_BIT))
226 #define _PAGE_PRESENT  (1 << xlate_pabit(_PAGE_PRESENT_BIT))
227 #define _PAGE_HUGE     (1 << xlate_pabit(_PAGE_HPAGE_BIT))
228 #define _PAGE_USER     (1 << xlate_pabit(_PAGE_USER_BIT))
229 
230 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)
231 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
232 #define _PAGE_KERNEL_RO	(_PAGE_PRESENT | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED)
233 #define _PAGE_KERNEL_EXEC	(_PAGE_KERNEL_RO | _PAGE_EXEC)
234 #define _PAGE_KERNEL_RWX	(_PAGE_KERNEL_EXEC | _PAGE_WRITE)
235 #define _PAGE_KERNEL		(_PAGE_KERNEL_RO | _PAGE_WRITE)
236 
237 /* The pgd/pmd contains a ptr (in phys addr space); since all pgds/pmds
238  * are page-aligned, we don't care about the PAGE_OFFSET bits, except
239  * for a few meta-information bits, so we shift the address to be
240  * able to effectively address 40/42/44-bits of physical address space
241  * depending on 4k/16k/64k PAGE_SIZE */
242 #define _PxD_PRESENT_BIT   31
243 #define _PxD_ATTACHED_BIT  30
244 #define _PxD_VALID_BIT     29
245 
246 #define PxD_FLAG_PRESENT  (1 << xlate_pabit(_PxD_PRESENT_BIT))
247 #define PxD_FLAG_ATTACHED (1 << xlate_pabit(_PxD_ATTACHED_BIT))
248 #define PxD_FLAG_VALID    (1 << xlate_pabit(_PxD_VALID_BIT))
249 #define PxD_FLAG_MASK     (0xf)
250 #define PxD_FLAG_SHIFT    (4)
251 #define PxD_VALUE_SHIFT   (PFN_PTE_SHIFT-PxD_FLAG_SHIFT)
252 
253 #ifndef __ASSEMBLY__
254 
255 #define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_USER)
256 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE)
257 /* Others seem to make this executable, I don't know if that's correct
258    or not.  The stack is mapped this way though so this is necessary
259    in the short term - dhd@linuxcare.com, 2000-08-08 */
260 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ)
261 #define PAGE_WRITEONLY  __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITE)
262 #define PAGE_EXECREAD   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_EXEC)
263 #define PAGE_COPY       PAGE_EXECREAD
264 #define PAGE_RWX        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)
265 #define PAGE_KERNEL	__pgprot(_PAGE_KERNEL)
266 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL_EXEC)
267 #define PAGE_KERNEL_RWX	__pgprot(_PAGE_KERNEL_RWX)
268 #define PAGE_KERNEL_RO	__pgprot(_PAGE_KERNEL_RO)
269 #define PAGE_KERNEL_UNC	__pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
270 #define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_GATEWAY| _PAGE_READ)
271 
272 
273 /*
274  * We could have an execute only page using "gateway - promote to priv
275  * level 3", but that is kind of silly. So, the way things are defined
276  * now, we must always have read permission for pages with execute
277  * permission. For the fun of it we'll go ahead and support write only
278  * pages.
279  */
280 
281 	 /*xwr*/
282 #define __P000  PAGE_NONE
283 #define __P001  PAGE_READONLY
284 #define __P010  __P000 /* copy on write */
285 #define __P011  __P001 /* copy on write */
286 #define __P100  PAGE_EXECREAD
287 #define __P101  PAGE_EXECREAD
288 #define __P110  __P100 /* copy on write */
289 #define __P111  __P101 /* copy on write */
290 
291 #define __S000  PAGE_NONE
292 #define __S001  PAGE_READONLY
293 #define __S010  PAGE_WRITEONLY
294 #define __S011  PAGE_SHARED
295 #define __S100  PAGE_EXECREAD
296 #define __S101  PAGE_EXECREAD
297 #define __S110  PAGE_RWX
298 #define __S111  PAGE_RWX
299 
300 
301 extern pgd_t swapper_pg_dir[]; /* declared in init_task.c */
302 
303 /* initial page tables for 0-8MB for kernel */
304 
305 extern pte_t pg0[];
306 
307 /* zero page used for uninitialized stuff */
308 
309 extern unsigned long *empty_zero_page;
310 
311 /*
312  * ZERO_PAGE is a global shared page that is always zero: used
313  * for zero-mapped memory areas etc..
314  */
315 
316 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
317 
318 #define pte_none(x)     (pte_val(x) == 0)
319 #define pte_present(x)	(pte_val(x) & _PAGE_PRESENT)
320 #define pte_clear(mm, addr, xp)  set_pte_at(mm, addr, xp, __pte(0))
321 
322 #define pmd_flag(x)	(pmd_val(x) & PxD_FLAG_MASK)
323 #define pmd_address(x)	((unsigned long)(pmd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
324 #define pud_flag(x)	(pud_val(x) & PxD_FLAG_MASK)
325 #define pud_address(x)	((unsigned long)(pud_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
326 #define pgd_flag(x)	(pgd_val(x) & PxD_FLAG_MASK)
327 #define pgd_address(x)	((unsigned long)(pgd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
328 
329 #if CONFIG_PGTABLE_LEVELS == 3
330 /* The first entry of the permanent pmd is not there if it contains
331  * the gateway marker */
332 #define pmd_none(x)	(!pmd_val(x) || pmd_flag(x) == PxD_FLAG_ATTACHED)
333 #else
334 #define pmd_none(x)	(!pmd_val(x))
335 #endif
336 #define pmd_bad(x)	(!(pmd_flag(x) & PxD_FLAG_VALID))
337 #define pmd_present(x)	(pmd_flag(x) & PxD_FLAG_PRESENT)
338 static inline void pmd_clear(pmd_t *pmd) {
339 #if CONFIG_PGTABLE_LEVELS == 3
340 	if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
341 		/* This is the entry pointing to the permanent pmd
342 		 * attached to the pgd; cannot clear it */
343 		set_pmd(pmd, __pmd(PxD_FLAG_ATTACHED));
344 	else
345 #endif
346 		set_pmd(pmd,  __pmd(0));
347 }
348 
349 
350 
351 #if CONFIG_PGTABLE_LEVELS == 3
352 #define pud_page_vaddr(pud) ((unsigned long) __va(pud_address(pud)))
353 #define pud_page(pud)	virt_to_page((void *)pud_page_vaddr(pud))
354 
355 /* For 64 bit we have three level tables */
356 
357 #define pud_none(x)     (!pud_val(x))
358 #define pud_bad(x)      (!(pud_flag(x) & PxD_FLAG_VALID))
359 #define pud_present(x)  (pud_flag(x) & PxD_FLAG_PRESENT)
360 static inline void pud_clear(pud_t *pud) {
361 #if CONFIG_PGTABLE_LEVELS == 3
362 	if(pud_flag(*pud) & PxD_FLAG_ATTACHED)
363 		/* This is the permanent pmd attached to the pud; cannot
364 		 * free it */
365 		return;
366 #endif
367 	set_pud(pud, __pud(0));
368 }
369 #endif
370 
371 /*
372  * The following only work if pte_present() is true.
373  * Undefined behaviour if not..
374  */
375 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
376 static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
377 static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_WRITE; }
378 
379 static inline pte_t pte_mkclean(pte_t pte)	{ pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
380 static inline pte_t pte_mkold(pte_t pte)	{ pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
381 static inline pte_t pte_wrprotect(pte_t pte)	{ pte_val(pte) &= ~_PAGE_WRITE; return pte; }
382 static inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= _PAGE_DIRTY; return pte; }
383 static inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= _PAGE_ACCESSED; return pte; }
384 static inline pte_t pte_mkwrite(pte_t pte)	{ pte_val(pte) |= _PAGE_WRITE; return pte; }
385 
386 /*
387  * Huge pte definitions.
388  */
389 #ifdef CONFIG_HUGETLB_PAGE
390 #define pte_huge(pte)           (pte_val(pte) & _PAGE_HUGE)
391 #define pte_mkhuge(pte)         (__pte(pte_val(pte) | \
392 				 (parisc_requires_coherency() ? 0 : _PAGE_HUGE)))
393 #else
394 #define pte_huge(pte)           (0)
395 #define pte_mkhuge(pte)         (pte)
396 #endif
397 
398 
399 /*
400  * Conversion functions: convert a page and protection to a page entry,
401  * and a page entry and page directory to the page they refer to.
402  */
403 #define __mk_pte(addr,pgprot) \
404 ({									\
405 	pte_t __pte;							\
406 									\
407 	pte_val(__pte) = ((((addr)>>PAGE_SHIFT)<<PFN_PTE_SHIFT) + pgprot_val(pgprot));	\
408 									\
409 	__pte;								\
410 })
411 
412 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
413 
414 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
415 {
416 	pte_t pte;
417 	pte_val(pte) = (pfn << PFN_PTE_SHIFT) | pgprot_val(pgprot);
418 	return pte;
419 }
420 
421 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
422 { pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
423 
424 /* Permanent address of a page.  On parisc we don't have highmem. */
425 
426 #define pte_pfn(x)		(pte_val(x) >> PFN_PTE_SHIFT)
427 
428 #define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
429 
430 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
431 {
432 	return ((unsigned long) __va(pmd_address(pmd)));
433 }
434 
435 #define __pmd_page(pmd) ((unsigned long) __va(pmd_address(pmd)))
436 #define pmd_page(pmd)	virt_to_page((void *)__pmd_page(pmd))
437 
438 /* Find an entry in the second-level page table.. */
439 
440 extern void paging_init (void);
441 
442 /* Used for deferring calls to flush_dcache_page() */
443 
444 #define PG_dcache_dirty         PG_arch_1
445 
446 extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t *);
447 
448 /* Encode and de-code a swap entry */
449 
450 #define __swp_type(x)                     ((x).val & 0x1f)
451 #define __swp_offset(x)                   ( (((x).val >> 6) &  0x7) | \
452 					  (((x).val >> 8) & ~0x7) )
453 #define __swp_entry(type, offset)         ((swp_entry_t) { (type) | \
454 					    ((offset &  0x7) << 6) | \
455 					    ((offset & ~0x7) << 8) })
456 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
457 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
458 
459 
460 static inline spinlock_t *pgd_spinlock(pgd_t *pgd)
461 {
462 	if (unlikely(pgd == swapper_pg_dir))
463 		return &pa_swapper_pg_lock;
464 	return (spinlock_t *)((char *)pgd + (PAGE_SIZE << (PGD_ALLOC_ORDER - 1)));
465 }
466 
467 
468 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
469 {
470 	pte_t pte;
471 	unsigned long flags;
472 
473 	if (!pte_young(*ptep))
474 		return 0;
475 
476 	spin_lock_irqsave(pgd_spinlock(vma->vm_mm->pgd), flags);
477 	pte = *ptep;
478 	if (!pte_young(pte)) {
479 		spin_unlock_irqrestore(pgd_spinlock(vma->vm_mm->pgd), flags);
480 		return 0;
481 	}
482 	set_pte(ptep, pte_mkold(pte));
483 	purge_tlb_entries(vma->vm_mm, addr);
484 	spin_unlock_irqrestore(pgd_spinlock(vma->vm_mm->pgd), flags);
485 	return 1;
486 }
487 
488 struct mm_struct;
489 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
490 {
491 	pte_t old_pte;
492 	unsigned long flags;
493 
494 	spin_lock_irqsave(pgd_spinlock(mm->pgd), flags);
495 	old_pte = *ptep;
496 	set_pte(ptep, __pte(0));
497 	purge_tlb_entries(mm, addr);
498 	spin_unlock_irqrestore(pgd_spinlock(mm->pgd), flags);
499 
500 	return old_pte;
501 }
502 
503 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
504 {
505 	unsigned long flags;
506 	spin_lock_irqsave(pgd_spinlock(mm->pgd), flags);
507 	set_pte(ptep, pte_wrprotect(*ptep));
508 	purge_tlb_entries(mm, addr);
509 	spin_unlock_irqrestore(pgd_spinlock(mm->pgd), flags);
510 }
511 
512 #define pte_same(A,B)	(pte_val(A) == pte_val(B))
513 
514 struct seq_file;
515 extern void arch_report_meminfo(struct seq_file *m);
516 
517 #endif /* !__ASSEMBLY__ */
518 
519 
520 /* TLB page size encoding - see table 3-1 in parisc20.pdf */
521 #define _PAGE_SIZE_ENCODING_4K		0
522 #define _PAGE_SIZE_ENCODING_16K		1
523 #define _PAGE_SIZE_ENCODING_64K		2
524 #define _PAGE_SIZE_ENCODING_256K	3
525 #define _PAGE_SIZE_ENCODING_1M		4
526 #define _PAGE_SIZE_ENCODING_4M		5
527 #define _PAGE_SIZE_ENCODING_16M		6
528 #define _PAGE_SIZE_ENCODING_64M		7
529 
530 #if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
531 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_4K
532 #elif defined(CONFIG_PARISC_PAGE_SIZE_16KB)
533 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_16K
534 #elif defined(CONFIG_PARISC_PAGE_SIZE_64KB)
535 # define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_64K
536 #endif
537 
538 
539 #define pgprot_noncached(prot) __pgprot(pgprot_val(prot) | _PAGE_NO_CACHE)
540 
541 /* We provide our own get_unmapped_area to provide cache coherency */
542 
543 #define HAVE_ARCH_UNMAPPED_AREA
544 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
545 
546 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
547 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
548 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
549 #define __HAVE_ARCH_PTE_SAME
550 
551 #endif /* _PARISC_PGTABLE_H */
552