xref: /openbmc/linux/arch/powerpc/include/asm/book3s/32/pgtable.h (revision 22fc4c4c9fd60427bcda00878cee94e7622cfa7a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_BOOK3S_32_PGTABLE_H
3 #define _ASM_POWERPC_BOOK3S_32_PGTABLE_H
4 
5 #define __ARCH_USE_5LEVEL_HACK
6 #include <asm-generic/pgtable-nopmd.h>
7 
8 #include <asm/book3s/32/hash.h>
9 
10 /* And here we include common definitions */
11 
12 #define _PAGE_KERNEL_RO		0
13 #define _PAGE_KERNEL_ROX	(_PAGE_EXEC)
14 #define _PAGE_KERNEL_RW		(_PAGE_DIRTY | _PAGE_RW)
15 #define _PAGE_KERNEL_RWX	(_PAGE_DIRTY | _PAGE_RW | _PAGE_EXEC)
16 
17 #define _PAGE_HPTEFLAGS _PAGE_HASHPTE
18 
19 #ifndef __ASSEMBLY__
20 
21 static inline bool pte_user(pte_t pte)
22 {
23 	return pte_val(pte) & _PAGE_USER;
24 }
25 #endif /* __ASSEMBLY__ */
26 
27 /*
28  * Location of the PFN in the PTE. Most 32-bit platforms use the same
29  * as _PAGE_SHIFT here (ie, naturally aligned).
30  * Platform who don't just pre-define the value so we don't override it here.
31  */
32 #define PTE_RPN_SHIFT	(PAGE_SHIFT)
33 
34 /*
35  * The mask covered by the RPN must be a ULL on 32-bit platforms with
36  * 64-bit PTEs.
37  */
38 #ifdef CONFIG_PTE_64BIT
39 #define PTE_RPN_MASK	(~((1ULL << PTE_RPN_SHIFT) - 1))
40 #else
41 #define PTE_RPN_MASK	(~((1UL << PTE_RPN_SHIFT) - 1))
42 #endif
43 
44 /*
45  * _PAGE_CHG_MASK masks of bits that are to be preserved across
46  * pgprot changes.
47  */
48 #define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HASHPTE | _PAGE_DIRTY | \
49 			 _PAGE_ACCESSED | _PAGE_SPECIAL)
50 
51 /*
52  * We define 2 sets of base prot bits, one for basic pages (ie,
53  * cacheable kernel and user pages) and one for non cacheable
54  * pages. We always set _PAGE_COHERENT when SMP is enabled or
55  * the processor might need it for DMA coherency.
56  */
57 #define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED)
58 #define _PAGE_BASE	(_PAGE_BASE_NC | _PAGE_COHERENT)
59 
60 /*
61  * Permission masks used to generate the __P and __S table.
62  *
63  * Note:__pgprot is defined in arch/powerpc/include/asm/page.h
64  *
65  * Write permissions imply read permissions for now.
66  */
67 #define PAGE_NONE	__pgprot(_PAGE_BASE)
68 #define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
69 #define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
70 #define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
71 #define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
72 #define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
73 #define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
74 
75 /* Permission masks used for kernel mappings */
76 #define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
77 #define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE)
78 #define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
79 				 _PAGE_NO_CACHE | _PAGE_GUARDED)
80 #define PAGE_KERNEL_X	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX)
81 #define PAGE_KERNEL_RO	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
82 #define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
83 
84 /*
85  * Protection used for kernel text. We want the debuggers to be able to
86  * set breakpoints anywhere, so don't write protect the kernel text
87  * on platforms where such control is possible.
88  */
89 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
90 	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
91 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
92 #else
93 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
94 #endif
95 
96 /* Make modules code happy. We don't set RO yet */
97 #define PAGE_KERNEL_EXEC	PAGE_KERNEL_X
98 
99 /* Advertise special mapping type for AGP */
100 #define PAGE_AGP		(PAGE_KERNEL_NC)
101 #define HAVE_PAGE_AGP
102 
103 #define PTE_INDEX_SIZE	PTE_SHIFT
104 #define PMD_INDEX_SIZE	0
105 #define PUD_INDEX_SIZE	0
106 #define PGD_INDEX_SIZE	(32 - PGDIR_SHIFT)
107 
108 #define PMD_CACHE_INDEX	PMD_INDEX_SIZE
109 #define PUD_CACHE_INDEX	PUD_INDEX_SIZE
110 
111 #ifndef __ASSEMBLY__
112 #define PTE_TABLE_SIZE	(sizeof(pte_t) << PTE_INDEX_SIZE)
113 #define PMD_TABLE_SIZE	0
114 #define PUD_TABLE_SIZE	0
115 #define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)
116 #endif	/* __ASSEMBLY__ */
117 
118 #define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
119 #define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)
120 
121 /*
122  * The normal case is that PTEs are 32-bits and we have a 1-page
123  * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
124  *
125  * For any >32-bit physical address platform, we can use the following
126  * two level page table layout where the pgdir is 8KB and the MS 13 bits
127  * are an index to the second level table.  The combined pgdir/pmd first
128  * level has 2048 entries and the second level has 512 64-bit PTE entries.
129  * -Matt
130  */
131 /* PGDIR_SHIFT determines what a top-level page table entry can map */
132 #define PGDIR_SHIFT	(PAGE_SHIFT + PTE_INDEX_SIZE)
133 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
134 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
135 
136 #define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
137 /*
138  * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
139  * value (for now) on others, from where we can start layout kernel
140  * virtual space that goes below PKMAP and FIXMAP
141  */
142 #ifdef CONFIG_HIGHMEM
143 #define KVIRT_TOP	PKMAP_BASE
144 #else
145 #define KVIRT_TOP	(0xfe000000UL)	/* for now, could be FIXMAP_BASE ? */
146 #endif
147 
148 /*
149  * ioremap_bot starts at that address. Early ioremaps move down from there,
150  * until mem_init() at which point this becomes the top of the vmalloc
151  * and ioremap space
152  */
153 #ifdef CONFIG_NOT_COHERENT_CACHE
154 #define IOREMAP_TOP	((KVIRT_TOP - CONFIG_CONSISTENT_SIZE) & PAGE_MASK)
155 #else
156 #define IOREMAP_TOP	KVIRT_TOP
157 #endif
158 
159 /*
160  * Just any arbitrary offset to the start of the vmalloc VM area: the
161  * current 16MB value just means that there will be a 64MB "hole" after the
162  * physical memory until the kernel virtual memory starts.  That means that
163  * any out-of-bounds memory accesses will hopefully be caught.
164  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
165  * area for the same reason. ;)
166  *
167  * We no longer map larger than phys RAM with the BATs so we don't have
168  * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
169  * about clashes between our early calls to ioremap() that start growing down
170  * from ioremap_base being run into the VM area allocations (growing upwards
171  * from VMALLOC_START).  For this reason we have ioremap_bot to check when
172  * we actually run into our mappings setup in the early boot with the VM
173  * system.  This really does become a problem for machines with good amounts
174  * of RAM.  -- Cort
175  */
176 #define VMALLOC_OFFSET (0x1000000) /* 16M */
177 #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
178 #define VMALLOC_END	ioremap_bot
179 
180 #ifndef __ASSEMBLY__
181 #include <linux/sched.h>
182 #include <linux/threads.h>
183 
184 extern unsigned long ioremap_bot;
185 
186 /* Bits to mask out from a PGD to get to the PUD page */
187 #define PGD_MASKED_BITS		0
188 
189 #define pte_ERROR(e) \
190 	pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
191 		(unsigned long long)pte_val(e))
192 #define pgd_ERROR(e) \
193 	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
194 /*
195  * Bits in a linux-style PTE.  These match the bits in the
196  * (hardware-defined) PowerPC PTE as closely as possible.
197  */
198 
199 #define pte_clear(mm, addr, ptep) \
200 	do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
201 
202 #define pmd_none(pmd)		(!pmd_val(pmd))
203 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
204 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
205 static inline void pmd_clear(pmd_t *pmdp)
206 {
207 	*pmdp = __pmd(0);
208 }
209 
210 
211 /*
212  * When flushing the tlb entry for a page, we also need to flush the hash
213  * table entry.  flush_hash_pages is assembler (for speed) in hashtable.S.
214  */
215 extern int flush_hash_pages(unsigned context, unsigned long va,
216 			    unsigned long pmdval, int count);
217 
218 /* Add an HPTE to the hash table */
219 extern void add_hash_page(unsigned context, unsigned long va,
220 			  unsigned long pmdval);
221 
222 /* Flush an entry from the TLB/hash table */
223 extern void flush_hash_entry(struct mm_struct *mm, pte_t *ptep,
224 			     unsigned long address);
225 
226 /*
227  * PTE updates. This function is called whenever an existing
228  * valid PTE is updated. This does -not- include set_pte_at()
229  * which nowadays only sets a new PTE.
230  *
231  * Depending on the type of MMU, we may need to use atomic updates
232  * and the PTE may be either 32 or 64 bit wide. In the later case,
233  * when using atomic updates, only the low part of the PTE is
234  * accessed atomically.
235  *
236  * In addition, on 44x, we also maintain a global flag indicating
237  * that an executable user mapping was modified, which is needed
238  * to properly flush the virtually tagged instruction cache of
239  * those implementations.
240  */
241 #ifndef CONFIG_PTE_64BIT
242 static inline unsigned long pte_update(pte_t *p,
243 				       unsigned long clr,
244 				       unsigned long set)
245 {
246 	unsigned long old, tmp;
247 
248 	__asm__ __volatile__("\
249 1:	lwarx	%0,0,%3\n\
250 	andc	%1,%0,%4\n\
251 	or	%1,%1,%5\n"
252 "	stwcx.	%1,0,%3\n\
253 	bne-	1b"
254 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
255 	: "r" (p), "r" (clr), "r" (set), "m" (*p)
256 	: "cc" );
257 
258 	return old;
259 }
260 #else /* CONFIG_PTE_64BIT */
261 static inline unsigned long long pte_update(pte_t *p,
262 					    unsigned long clr,
263 					    unsigned long set)
264 {
265 	unsigned long long old;
266 	unsigned long tmp;
267 
268 	__asm__ __volatile__("\
269 1:	lwarx	%L0,0,%4\n\
270 	lwzx	%0,0,%3\n\
271 	andc	%1,%L0,%5\n\
272 	or	%1,%1,%6\n"
273 "	stwcx.	%1,0,%4\n\
274 	bne-	1b"
275 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
276 	: "r" (p), "r" ((unsigned long)(p) + 4), "r" (clr), "r" (set), "m" (*p)
277 	: "cc" );
278 
279 	return old;
280 }
281 #endif /* CONFIG_PTE_64BIT */
282 
283 /*
284  * 2.6 calls this without flushing the TLB entry; this is wrong
285  * for our hash-based implementation, we fix that up here.
286  */
287 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
288 static inline int __ptep_test_and_clear_young(unsigned int context, unsigned long addr, pte_t *ptep)
289 {
290 	unsigned long old;
291 	old = pte_update(ptep, _PAGE_ACCESSED, 0);
292 	if (old & _PAGE_HASHPTE) {
293 		unsigned long ptephys = __pa(ptep) & PAGE_MASK;
294 		flush_hash_pages(context, addr, ptephys, 1);
295 	}
296 	return (old & _PAGE_ACCESSED) != 0;
297 }
298 #define ptep_test_and_clear_young(__vma, __addr, __ptep) \
299 	__ptep_test_and_clear_young((__vma)->vm_mm->context.id, __addr, __ptep)
300 
301 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
302 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
303 				       pte_t *ptep)
304 {
305 	return __pte(pte_update(ptep, ~_PAGE_HASHPTE, 0));
306 }
307 
308 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
309 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
310 				      pte_t *ptep)
311 {
312 	pte_update(ptep, _PAGE_RW, 0);
313 }
314 
315 static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
316 					   pte_t *ptep, pte_t entry,
317 					   unsigned long address,
318 					   int psize)
319 {
320 	unsigned long set = pte_val(entry) &
321 		(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
322 
323 	pte_update(ptep, 0, set);
324 
325 	flush_tlb_page(vma, address);
326 }
327 
328 #define __HAVE_ARCH_PTE_SAME
329 #define pte_same(A,B)	(((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)
330 
331 #define pmd_page_vaddr(pmd)	\
332 	((unsigned long)__va(pmd_val(pmd) & ~(PTE_TABLE_SIZE - 1)))
333 #define pmd_page(pmd)		\
334 	pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
335 
336 /* to find an entry in a kernel page-table-directory */
337 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
338 
339 /* to find an entry in a page-table-directory */
340 #define pgd_index(address)	 ((address) >> PGDIR_SHIFT)
341 #define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))
342 
343 /* Find an entry in the third-level page table.. */
344 #define pte_index(address)		\
345 	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
346 #define pte_offset_kernel(dir, addr)	\
347 	((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(addr))
348 #define pte_offset_map(dir, addr)		\
349 	((pte_t *)(kmap_atomic(pmd_page(*(dir))) + \
350 		   (pmd_page_vaddr(*(dir)) & ~PAGE_MASK)) + pte_index(addr))
351 #define pte_unmap(pte)		kunmap_atomic(pte)
352 
353 /*
354  * Encode and decode a swap entry.
355  * Note that the bits we use in a PTE for representing a swap entry
356  * must not include the _PAGE_PRESENT bit or the _PAGE_HASHPTE bit (if used).
357  *   -- paulus
358  */
359 #define __swp_type(entry)		((entry).val & 0x1f)
360 #define __swp_offset(entry)		((entry).val >> 5)
361 #define __swp_entry(type, offset)	((swp_entry_t) { (type) | ((offset) << 5) })
362 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
363 #define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })
364 
365 int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
366 
367 /* Generic accessors to PTE bits */
368 static inline int pte_write(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_RW);}
369 static inline int pte_read(pte_t pte)		{ return 1; }
370 static inline int pte_dirty(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_DIRTY); }
371 static inline int pte_young(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_ACCESSED); }
372 static inline int pte_special(pte_t pte)	{ return !!(pte_val(pte) & _PAGE_SPECIAL); }
373 static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
374 static inline bool pte_exec(pte_t pte)		{ return pte_val(pte) & _PAGE_EXEC; }
375 
376 static inline int pte_present(pte_t pte)
377 {
378 	return pte_val(pte) & _PAGE_PRESENT;
379 }
380 
381 static inline bool pte_hw_valid(pte_t pte)
382 {
383 	return pte_val(pte) & _PAGE_PRESENT;
384 }
385 
386 static inline bool pte_hashpte(pte_t pte)
387 {
388 	return !!(pte_val(pte) & _PAGE_HASHPTE);
389 }
390 
391 static inline bool pte_ci(pte_t pte)
392 {
393 	return !!(pte_val(pte) & _PAGE_NO_CACHE);
394 }
395 
396 /*
397  * We only find page table entry in the last level
398  * Hence no need for other accessors
399  */
400 #define pte_access_permitted pte_access_permitted
401 static inline bool pte_access_permitted(pte_t pte, bool write)
402 {
403 	/*
404 	 * A read-only access is controlled by _PAGE_USER bit.
405 	 * We have _PAGE_READ set for WRITE and EXECUTE
406 	 */
407 	if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte))
408 		return false;
409 
410 	if (write && !pte_write(pte))
411 		return false;
412 
413 	return true;
414 }
415 
416 /* Conversion functions: convert a page and protection to a page entry,
417  * and a page entry and page directory to the page they refer to.
418  *
419  * Even if PTEs can be unsigned long long, a PFN is always an unsigned
420  * long for now.
421  */
422 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
423 {
424 	return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
425 		     pgprot_val(pgprot));
426 }
427 
428 static inline unsigned long pte_pfn(pte_t pte)
429 {
430 	return pte_val(pte) >> PTE_RPN_SHIFT;
431 }
432 
433 /* Generic modifiers for PTE bits */
434 static inline pte_t pte_wrprotect(pte_t pte)
435 {
436 	return __pte(pte_val(pte) & ~_PAGE_RW);
437 }
438 
439 static inline pte_t pte_exprotect(pte_t pte)
440 {
441 	return __pte(pte_val(pte) & ~_PAGE_EXEC);
442 }
443 
444 static inline pte_t pte_mkclean(pte_t pte)
445 {
446 	return __pte(pte_val(pte) & ~_PAGE_DIRTY);
447 }
448 
449 static inline pte_t pte_mkold(pte_t pte)
450 {
451 	return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
452 }
453 
454 static inline pte_t pte_mkexec(pte_t pte)
455 {
456 	return __pte(pte_val(pte) | _PAGE_EXEC);
457 }
458 
459 static inline pte_t pte_mkpte(pte_t pte)
460 {
461 	return pte;
462 }
463 
464 static inline pte_t pte_mkwrite(pte_t pte)
465 {
466 	return __pte(pte_val(pte) | _PAGE_RW);
467 }
468 
469 static inline pte_t pte_mkdirty(pte_t pte)
470 {
471 	return __pte(pte_val(pte) | _PAGE_DIRTY);
472 }
473 
474 static inline pte_t pte_mkyoung(pte_t pte)
475 {
476 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
477 }
478 
479 static inline pte_t pte_mkspecial(pte_t pte)
480 {
481 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
482 }
483 
484 static inline pte_t pte_mkhuge(pte_t pte)
485 {
486 	return pte;
487 }
488 
489 static inline pte_t pte_mkprivileged(pte_t pte)
490 {
491 	return __pte(pte_val(pte) & ~_PAGE_USER);
492 }
493 
494 static inline pte_t pte_mkuser(pte_t pte)
495 {
496 	return __pte(pte_val(pte) | _PAGE_USER);
497 }
498 
499 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
500 {
501 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
502 }
503 
504 
505 
506 /* This low level function performs the actual PTE insertion
507  * Setting the PTE depends on the MMU type and other factors. It's
508  * an horrible mess that I'm not going to try to clean up now but
509  * I'm keeping it in one place rather than spread around
510  */
511 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
512 				pte_t *ptep, pte_t pte, int percpu)
513 {
514 #if defined(CONFIG_SMP) && !defined(CONFIG_PTE_64BIT)
515 	/* First case is 32-bit Hash MMU in SMP mode with 32-bit PTEs. We use the
516 	 * helper pte_update() which does an atomic update. We need to do that
517 	 * because a concurrent invalidation can clear _PAGE_HASHPTE. If it's a
518 	 * per-CPU PTE such as a kmap_atomic, we do a simple update preserving
519 	 * the hash bits instead (ie, same as the non-SMP case)
520 	 */
521 	if (percpu)
522 		*ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
523 			      | (pte_val(pte) & ~_PAGE_HASHPTE));
524 	else
525 		pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte));
526 
527 #elif defined(CONFIG_PTE_64BIT)
528 	/* Second case is 32-bit with 64-bit PTE.  In this case, we
529 	 * can just store as long as we do the two halves in the right order
530 	 * with a barrier in between. This is possible because we take care,
531 	 * in the hash code, to pre-invalidate if the PTE was already hashed,
532 	 * which synchronizes us with any concurrent invalidation.
533 	 * In the percpu case, we also fallback to the simple update preserving
534 	 * the hash bits
535 	 */
536 	if (percpu) {
537 		*ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
538 			      | (pte_val(pte) & ~_PAGE_HASHPTE));
539 		return;
540 	}
541 	if (pte_val(*ptep) & _PAGE_HASHPTE)
542 		flush_hash_entry(mm, ptep, addr);
543 	__asm__ __volatile__("\
544 		stw%U0%X0 %2,%0\n\
545 		eieio\n\
546 		stw%U0%X0 %L2,%1"
547 	: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
548 	: "r" (pte) : "memory");
549 
550 #else
551 	/* Third case is 32-bit hash table in UP mode, we need to preserve
552 	 * the _PAGE_HASHPTE bit since we may not have invalidated the previous
553 	 * translation in the hash yet (done in a subsequent flush_tlb_xxx())
554 	 * and see we need to keep track that this PTE needs invalidating
555 	 */
556 	*ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
557 		      | (pte_val(pte) & ~_PAGE_HASHPTE));
558 #endif
559 }
560 
561 /*
562  * Macro to mark a page protection value as "uncacheable".
563  */
564 
565 #define _PAGE_CACHE_CTL	(_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
566 			 _PAGE_WRITETHRU)
567 
568 #define pgprot_noncached pgprot_noncached
569 static inline pgprot_t pgprot_noncached(pgprot_t prot)
570 {
571 	return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
572 			_PAGE_NO_CACHE | _PAGE_GUARDED);
573 }
574 
575 #define pgprot_noncached_wc pgprot_noncached_wc
576 static inline pgprot_t pgprot_noncached_wc(pgprot_t prot)
577 {
578 	return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
579 			_PAGE_NO_CACHE);
580 }
581 
582 #define pgprot_cached pgprot_cached
583 static inline pgprot_t pgprot_cached(pgprot_t prot)
584 {
585 	return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
586 			_PAGE_COHERENT);
587 }
588 
589 #define pgprot_cached_wthru pgprot_cached_wthru
590 static inline pgprot_t pgprot_cached_wthru(pgprot_t prot)
591 {
592 	return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
593 			_PAGE_COHERENT | _PAGE_WRITETHRU);
594 }
595 
596 #define pgprot_cached_noncoherent pgprot_cached_noncoherent
597 static inline pgprot_t pgprot_cached_noncoherent(pgprot_t prot)
598 {
599 	return __pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL);
600 }
601 
602 #define pgprot_writecombine pgprot_writecombine
603 static inline pgprot_t pgprot_writecombine(pgprot_t prot)
604 {
605 	return pgprot_noncached_wc(prot);
606 }
607 
608 #endif /* !__ASSEMBLY__ */
609 
610 #endif /*  _ASM_POWERPC_BOOK3S_32_PGTABLE_H */
611