xref: /linux/arch/s390/include/asm/pgtable.h (revision 30614cf34105c5b5b9a39c65a2ea32c58b03aa8e)
1 /*
2  *  S390 version
3  *    Copyright IBM Corp. 1999, 2000
4  *    Author(s): Hartmut Penner (hp@de.ibm.com)
5  *               Ulrich Weigand (weigand@de.ibm.com)
6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
7  *
8  *  Derived from "include/asm-i386/pgtable.h"
9  */
10 
11 #ifndef _ASM_S390_PGTABLE_H
12 #define _ASM_S390_PGTABLE_H
13 
14 /*
15  * The Linux memory management assumes a three-level page table setup. For
16  * s390 31 bit we "fold" the mid level into the top-level page table, so
17  * that we physically have the same two-level page table as the s390 mmu
18  * expects in 31 bit mode. For s390 64 bit we use three of the five levels
19  * the hardware provides (region first and region second tables are not
20  * used).
21  *
22  * The "pgd_xxx()" functions are trivial for a folded two-level
23  * setup: the pgd is never bad, and a pmd always exists (as it's folded
24  * into the pgd entry)
25  *
26  * This file contains the functions and defines necessary to modify and use
27  * the S390 page table tree.
28  */
29 #ifndef __ASSEMBLY__
30 #include <linux/sched.h>
31 #include <linux/mm_types.h>
32 #include <linux/page-flags.h>
33 #include <linux/radix-tree.h>
34 #include <asm/bug.h>
35 #include <asm/page.h>
36 
37 extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096)));
38 extern void paging_init(void);
39 extern void vmem_map_init(void);
40 
41 /*
42  * The S390 doesn't have any external MMU info: the kernel page
43  * tables contain all the necessary information.
44  */
45 #define update_mmu_cache(vma, address, ptep)     do { } while (0)
46 #define update_mmu_cache_pmd(vma, address, ptep) do { } while (0)
47 
48 /*
49  * ZERO_PAGE is a global shared page that is always zero; used
50  * for zero-mapped memory areas etc..
51  */
52 
53 extern unsigned long empty_zero_page;
54 extern unsigned long zero_page_mask;
55 
56 #define ZERO_PAGE(vaddr) \
57 	(virt_to_page((void *)(empty_zero_page + \
58 	 (((unsigned long)(vaddr)) &zero_page_mask))))
59 #define __HAVE_COLOR_ZERO_PAGE
60 
61 /* TODO: s390 cannot support io_remap_pfn_range... */
62 #endif /* !__ASSEMBLY__ */
63 
64 /*
65  * PMD_SHIFT determines the size of the area a second-level page
66  * table can map
67  * PGDIR_SHIFT determines what a third-level page table entry can map
68  */
69 #ifndef CONFIG_64BIT
70 # define PMD_SHIFT	20
71 # define PUD_SHIFT	20
72 # define PGDIR_SHIFT	20
73 #else /* CONFIG_64BIT */
74 # define PMD_SHIFT	20
75 # define PUD_SHIFT	31
76 # define PGDIR_SHIFT	42
77 #endif /* CONFIG_64BIT */
78 
79 #define PMD_SIZE        (1UL << PMD_SHIFT)
80 #define PMD_MASK        (~(PMD_SIZE-1))
81 #define PUD_SIZE	(1UL << PUD_SHIFT)
82 #define PUD_MASK	(~(PUD_SIZE-1))
83 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
84 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
85 
86 /*
87  * entries per page directory level: the S390 is two-level, so
88  * we don't really have any PMD directory physically.
89  * for S390 segment-table entries are combined to one PGD
90  * that leads to 1024 pte per pgd
91  */
92 #define PTRS_PER_PTE	256
93 #ifndef CONFIG_64BIT
94 #define PTRS_PER_PMD	1
95 #define PTRS_PER_PUD	1
96 #else /* CONFIG_64BIT */
97 #define PTRS_PER_PMD	2048
98 #define PTRS_PER_PUD	2048
99 #endif /* CONFIG_64BIT */
100 #define PTRS_PER_PGD	2048
101 
102 #define FIRST_USER_ADDRESS  0
103 
104 #define pte_ERROR(e) \
105 	printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e))
106 #define pmd_ERROR(e) \
107 	printk("%s:%d: bad pmd %p.\n", __FILE__, __LINE__, (void *) pmd_val(e))
108 #define pud_ERROR(e) \
109 	printk("%s:%d: bad pud %p.\n", __FILE__, __LINE__, (void *) pud_val(e))
110 #define pgd_ERROR(e) \
111 	printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) pgd_val(e))
112 
113 #ifndef __ASSEMBLY__
114 /*
115  * The vmalloc and module area will always be on the topmost area of the kernel
116  * mapping. We reserve 96MB (31bit) / 128GB (64bit) for vmalloc and modules.
117  * On 64 bit kernels we have a 2GB area at the top of the vmalloc area where
118  * modules will reside. That makes sure that inter module branches always
119  * happen without trampolines and in addition the placement within a 2GB frame
120  * is branch prediction unit friendly.
121  */
122 extern unsigned long VMALLOC_START;
123 extern unsigned long VMALLOC_END;
124 extern struct page *vmemmap;
125 
126 #define VMEM_MAX_PHYS ((unsigned long) vmemmap)
127 
128 #ifdef CONFIG_64BIT
129 extern unsigned long MODULES_VADDR;
130 extern unsigned long MODULES_END;
131 #define MODULES_VADDR	MODULES_VADDR
132 #define MODULES_END	MODULES_END
133 #define MODULES_LEN	(1UL << 31)
134 #endif
135 
136 /*
137  * A 31 bit pagetable entry of S390 has following format:
138  *  |   PFRA          |    |  OS  |
139  * 0                   0IP0
140  * 00000000001111111111222222222233
141  * 01234567890123456789012345678901
142  *
143  * I Page-Invalid Bit:    Page is not available for address-translation
144  * P Page-Protection Bit: Store access not possible for page
145  *
146  * A 31 bit segmenttable entry of S390 has following format:
147  *  |   P-table origin      |  |PTL
148  * 0                         IC
149  * 00000000001111111111222222222233
150  * 01234567890123456789012345678901
151  *
152  * I Segment-Invalid Bit:    Segment is not available for address-translation
153  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
154  * PTL Page-Table-Length:    Page-table length (PTL+1*16 entries -> up to 256)
155  *
156  * The 31 bit segmenttable origin of S390 has following format:
157  *
158  *  |S-table origin   |     | STL |
159  * X                   **GPS
160  * 00000000001111111111222222222233
161  * 01234567890123456789012345678901
162  *
163  * X Space-Switch event:
164  * G Segment-Invalid Bit:     *
165  * P Private-Space Bit:       Segment is not private (PoP 3-30)
166  * S Storage-Alteration:
167  * STL Segment-Table-Length:  Segment-table length (STL+1*16 entries -> up to 2048)
168  *
169  * A 64 bit pagetable entry of S390 has following format:
170  * |			 PFRA			      |0IPC|  OS  |
171  * 0000000000111111111122222222223333333333444444444455555555556666
172  * 0123456789012345678901234567890123456789012345678901234567890123
173  *
174  * I Page-Invalid Bit:    Page is not available for address-translation
175  * P Page-Protection Bit: Store access not possible for page
176  * C Change-bit override: HW is not required to set change bit
177  *
178  * A 64 bit segmenttable entry of S390 has following format:
179  * |        P-table origin                              |      TT
180  * 0000000000111111111122222222223333333333444444444455555555556666
181  * 0123456789012345678901234567890123456789012345678901234567890123
182  *
183  * I Segment-Invalid Bit:    Segment is not available for address-translation
184  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
185  * P Page-Protection Bit: Store access not possible for page
186  * TT Type 00
187  *
188  * A 64 bit region table entry of S390 has following format:
189  * |        S-table origin                             |   TF  TTTL
190  * 0000000000111111111122222222223333333333444444444455555555556666
191  * 0123456789012345678901234567890123456789012345678901234567890123
192  *
193  * I Segment-Invalid Bit:    Segment is not available for address-translation
194  * TT Type 01
195  * TF
196  * TL Table length
197  *
198  * The 64 bit regiontable origin of S390 has following format:
199  * |      region table origon                          |       DTTL
200  * 0000000000111111111122222222223333333333444444444455555555556666
201  * 0123456789012345678901234567890123456789012345678901234567890123
202  *
203  * X Space-Switch event:
204  * G Segment-Invalid Bit:
205  * P Private-Space Bit:
206  * S Storage-Alteration:
207  * R Real space
208  * TL Table-Length:
209  *
210  * A storage key has the following format:
211  * | ACC |F|R|C|0|
212  *  0   3 4 5 6 7
213  * ACC: access key
214  * F  : fetch protection bit
215  * R  : referenced bit
216  * C  : changed bit
217  */
218 
219 /* Hardware bits in the page table entry */
220 #define _PAGE_CO	0x100		/* HW Change-bit override */
221 #define _PAGE_PROTECT	0x200		/* HW read-only bit  */
222 #define _PAGE_INVALID	0x400		/* HW invalid bit    */
223 #define _PAGE_LARGE	0x800		/* Bit to mark a large pte */
224 
225 /* Software bits in the page table entry */
226 #define _PAGE_PRESENT	0x001		/* SW pte present bit */
227 #define _PAGE_TYPE	0x002		/* SW pte type bit */
228 #define _PAGE_YOUNG	0x004		/* SW pte young bit */
229 #define _PAGE_DIRTY	0x008		/* SW pte dirty bit */
230 #define _PAGE_READ	0x010		/* SW pte read bit */
231 #define _PAGE_WRITE	0x020		/* SW pte write bit */
232 #define _PAGE_SPECIAL	0x040		/* SW associated with special page */
233 #define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */
234 #define __HAVE_ARCH_PTE_SPECIAL
235 
236 /* Set of bits not changed in pte_modify */
237 #define _PAGE_CHG_MASK		(PAGE_MASK | _PAGE_SPECIAL | _PAGE_CO | \
238 				 _PAGE_DIRTY | _PAGE_YOUNG)
239 
240 /*
241  * handle_pte_fault uses pte_present, pte_none and pte_file to find out the
242  * pte type WITHOUT holding the page table lock. The _PAGE_PRESENT bit
243  * is used to distinguish present from not-present ptes. It is changed only
244  * with the page table lock held.
245  *
246  * The following table gives the different possible bit combinations for
247  * the pte hardware and software bits in the last 12 bits of a pte:
248  *
249  *				842100000000
250  *				000084210000
251  *				000000008421
252  *				.IR...wrdytp
253  * empty			.10...000000
254  * swap				.10...xxxx10
255  * file				.11...xxxxx0
256  * prot-none, clean, old	.11...000001
257  * prot-none, clean, young	.11...000101
258  * prot-none, dirty, old	.10...001001
259  * prot-none, dirty, young	.10...001101
260  * read-only, clean, old	.11...010001
261  * read-only, clean, young	.01...010101
262  * read-only, dirty, old	.11...011001
263  * read-only, dirty, young	.01...011101
264  * read-write, clean, old	.11...110001
265  * read-write, clean, young	.01...110101
266  * read-write, dirty, old	.10...111001
267  * read-write, dirty, young	.00...111101
268  *
269  * pte_present is true for the bit pattern .xx...xxxxx1, (pte & 0x001) == 0x001
270  * pte_none    is true for the bit pattern .10...xxxx00, (pte & 0x603) == 0x400
271  * pte_file    is true for the bit pattern .11...xxxxx0, (pte & 0x601) == 0x600
272  * pte_swap    is true for the bit pattern .10...xxxx10, (pte & 0x603) == 0x402
273  */
274 
275 #ifndef CONFIG_64BIT
276 
277 /* Bits in the segment table address-space-control-element */
278 #define _ASCE_SPACE_SWITCH	0x80000000UL	/* space switch event	    */
279 #define _ASCE_ORIGIN_MASK	0x7ffff000UL	/* segment table origin	    */
280 #define _ASCE_PRIVATE_SPACE	0x100	/* private space control	    */
281 #define _ASCE_ALT_EVENT		0x80	/* storage alteration event control */
282 #define _ASCE_TABLE_LENGTH	0x7f	/* 128 x 64 entries = 8k	    */
283 
284 /* Bits in the segment table entry */
285 #define _SEGMENT_ENTRY_BITS	0x7fffffffUL	/* Valid segment table bits */
286 #define _SEGMENT_ENTRY_ORIGIN	0x7fffffc0UL	/* page table origin	    */
287 #define _SEGMENT_ENTRY_PROTECT	0x200	/* page protection bit		    */
288 #define _SEGMENT_ENTRY_INVALID	0x20	/* invalid segment table entry	    */
289 #define _SEGMENT_ENTRY_COMMON	0x10	/* common segment bit		    */
290 #define _SEGMENT_ENTRY_PTL	0x0f	/* page table length		    */
291 
292 #define _SEGMENT_ENTRY_DIRTY	0	/* No sw dirty bit for 31-bit */
293 #define _SEGMENT_ENTRY_YOUNG	0	/* No sw young bit for 31-bit */
294 #define _SEGMENT_ENTRY_READ	0	/* No sw read bit for 31-bit */
295 #define _SEGMENT_ENTRY_WRITE	0	/* No sw write bit for 31-bit */
296 #define _SEGMENT_ENTRY_LARGE	0	/* No large pages for 31-bit */
297 #define _SEGMENT_ENTRY_BITS_LARGE 0
298 #define _SEGMENT_ENTRY_ORIGIN_LARGE 0
299 
300 #define _SEGMENT_ENTRY		(_SEGMENT_ENTRY_PTL)
301 #define _SEGMENT_ENTRY_EMPTY	(_SEGMENT_ENTRY_INVALID)
302 
303 /*
304  * Segment table entry encoding (I = invalid, R = read-only bit):
305  *		..R...I.....
306  * prot-none	..1...1.....
307  * read-only	..1...0.....
308  * read-write	..0...0.....
309  * empty	..0...1.....
310  */
311 
312 /* Page status table bits for virtualization */
313 #define PGSTE_ACC_BITS	0xf0000000UL
314 #define PGSTE_FP_BIT	0x08000000UL
315 #define PGSTE_PCL_BIT	0x00800000UL
316 #define PGSTE_HR_BIT	0x00400000UL
317 #define PGSTE_HC_BIT	0x00200000UL
318 #define PGSTE_GR_BIT	0x00040000UL
319 #define PGSTE_GC_BIT	0x00020000UL
320 #define PGSTE_UC_BIT	0x00008000UL	/* user dirty (migration) */
321 #define PGSTE_IN_BIT	0x00004000UL	/* IPTE notify bit */
322 
323 #else /* CONFIG_64BIT */
324 
325 /* Bits in the segment/region table address-space-control-element */
326 #define _ASCE_ORIGIN		~0xfffUL/* segment table origin		    */
327 #define _ASCE_PRIVATE_SPACE	0x100	/* private space control	    */
328 #define _ASCE_ALT_EVENT		0x80	/* storage alteration event control */
329 #define _ASCE_SPACE_SWITCH	0x40	/* space switch event		    */
330 #define _ASCE_REAL_SPACE	0x20	/* real space control		    */
331 #define _ASCE_TYPE_MASK		0x0c	/* asce table type mask		    */
332 #define _ASCE_TYPE_REGION1	0x0c	/* region first table type	    */
333 #define _ASCE_TYPE_REGION2	0x08	/* region second table type	    */
334 #define _ASCE_TYPE_REGION3	0x04	/* region third table type	    */
335 #define _ASCE_TYPE_SEGMENT	0x00	/* segment table type		    */
336 #define _ASCE_TABLE_LENGTH	0x03	/* region table length		    */
337 
338 /* Bits in the region table entry */
339 #define _REGION_ENTRY_ORIGIN	~0xfffUL/* region/segment table origin	    */
340 #define _REGION_ENTRY_PROTECT	0x200	/* region protection bit	    */
341 #define _REGION_ENTRY_INVALID	0x20	/* invalid region table entry	    */
342 #define _REGION_ENTRY_TYPE_MASK	0x0c	/* region/segment table type mask   */
343 #define _REGION_ENTRY_TYPE_R1	0x0c	/* region first table type	    */
344 #define _REGION_ENTRY_TYPE_R2	0x08	/* region second table type	    */
345 #define _REGION_ENTRY_TYPE_R3	0x04	/* region third table type	    */
346 #define _REGION_ENTRY_LENGTH	0x03	/* region third length		    */
347 
348 #define _REGION1_ENTRY		(_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_LENGTH)
349 #define _REGION1_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID)
350 #define _REGION2_ENTRY		(_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_LENGTH)
351 #define _REGION2_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID)
352 #define _REGION3_ENTRY		(_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_LENGTH)
353 #define _REGION3_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID)
354 
355 #define _REGION3_ENTRY_LARGE	0x400	/* RTTE-format control, large page  */
356 #define _REGION3_ENTRY_RO	0x200	/* page protection bit		    */
357 #define _REGION3_ENTRY_CO	0x100	/* change-recording override	    */
358 
359 /* Bits in the segment table entry */
360 #define _SEGMENT_ENTRY_BITS	0xfffffffffffffe33UL
361 #define _SEGMENT_ENTRY_BITS_LARGE 0xfffffffffff0ff33UL
362 #define _SEGMENT_ENTRY_ORIGIN_LARGE ~0xfffffUL /* large page address	    */
363 #define _SEGMENT_ENTRY_ORIGIN	~0x7ffUL/* segment table origin		    */
364 #define _SEGMENT_ENTRY_PROTECT	0x200	/* page protection bit		    */
365 #define _SEGMENT_ENTRY_INVALID	0x20	/* invalid segment table entry	    */
366 
367 #define _SEGMENT_ENTRY		(0)
368 #define _SEGMENT_ENTRY_EMPTY	(_SEGMENT_ENTRY_INVALID)
369 
370 #define _SEGMENT_ENTRY_DIRTY	0x2000	/* SW segment dirty bit */
371 #define _SEGMENT_ENTRY_YOUNG	0x1000	/* SW segment young bit */
372 #define _SEGMENT_ENTRY_SPLIT	0x0800	/* THP splitting bit */
373 #define _SEGMENT_ENTRY_LARGE	0x0400	/* STE-format control, large page */
374 #define _SEGMENT_ENTRY_CO	0x0100	/* change-recording override   */
375 #define _SEGMENT_ENTRY_READ	0x0002	/* SW segment read bit */
376 #define _SEGMENT_ENTRY_WRITE	0x0001	/* SW segment write bit */
377 
378 /*
379  * Segment table entry encoding (R = read-only, I = invalid, y = young bit):
380  *				dy..R...I...wr
381  * prot-none, clean, old	00..1...1...00
382  * prot-none, clean, young	01..1...1...00
383  * prot-none, dirty, old	10..1...1...00
384  * prot-none, dirty, young	11..1...1...00
385  * read-only, clean, old	00..1...1...01
386  * read-only, clean, young	01..1...0...01
387  * read-only, dirty, old	10..1...1...01
388  * read-only, dirty, young	11..1...0...01
389  * read-write, clean, old	00..1...1...11
390  * read-write, clean, young	01..1...0...11
391  * read-write, dirty, old	10..0...1...11
392  * read-write, dirty, young	11..0...0...11
393  * The segment table origin is used to distinguish empty (origin==0) from
394  * read-write, old segment table entries (origin!=0)
395  */
396 
397 #define _SEGMENT_ENTRY_SPLIT_BIT 11	/* THP splitting bit number */
398 
399 /* Page status table bits for virtualization */
400 #define PGSTE_ACC_BITS	0xf000000000000000UL
401 #define PGSTE_FP_BIT	0x0800000000000000UL
402 #define PGSTE_PCL_BIT	0x0080000000000000UL
403 #define PGSTE_HR_BIT	0x0040000000000000UL
404 #define PGSTE_HC_BIT	0x0020000000000000UL
405 #define PGSTE_GR_BIT	0x0004000000000000UL
406 #define PGSTE_GC_BIT	0x0002000000000000UL
407 #define PGSTE_UC_BIT	0x0000800000000000UL	/* user dirty (migration) */
408 #define PGSTE_IN_BIT	0x0000400000000000UL	/* IPTE notify bit */
409 
410 #endif /* CONFIG_64BIT */
411 
412 /* Guest Page State used for virtualization */
413 #define _PGSTE_GPS_ZERO		0x0000000080000000UL
414 #define _PGSTE_GPS_USAGE_MASK	0x0000000003000000UL
415 #define _PGSTE_GPS_USAGE_STABLE 0x0000000000000000UL
416 #define _PGSTE_GPS_USAGE_UNUSED 0x0000000001000000UL
417 
418 /*
419  * A user page table pointer has the space-switch-event bit, the
420  * private-space-control bit and the storage-alteration-event-control
421  * bit set. A kernel page table pointer doesn't need them.
422  */
423 #define _ASCE_USER_BITS		(_ASCE_SPACE_SWITCH | _ASCE_PRIVATE_SPACE | \
424 				 _ASCE_ALT_EVENT)
425 
426 /*
427  * Page protection definitions.
428  */
429 #define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_INVALID)
430 #define PAGE_READ	__pgprot(_PAGE_PRESENT | _PAGE_READ | \
431 				 _PAGE_INVALID | _PAGE_PROTECT)
432 #define PAGE_WRITE	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
433 				 _PAGE_INVALID | _PAGE_PROTECT)
434 
435 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
436 				 _PAGE_YOUNG | _PAGE_DIRTY)
437 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
438 				 _PAGE_YOUNG | _PAGE_DIRTY)
439 #define PAGE_KERNEL_RO	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_YOUNG | \
440 				 _PAGE_PROTECT)
441 
442 /*
443  * On s390 the page table entry has an invalid bit and a read-only bit.
444  * Read permission implies execute permission and write permission
445  * implies read permission.
446  */
447          /*xwr*/
448 #define __P000	PAGE_NONE
449 #define __P001	PAGE_READ
450 #define __P010	PAGE_READ
451 #define __P011	PAGE_READ
452 #define __P100	PAGE_READ
453 #define __P101	PAGE_READ
454 #define __P110	PAGE_READ
455 #define __P111	PAGE_READ
456 
457 #define __S000	PAGE_NONE
458 #define __S001	PAGE_READ
459 #define __S010	PAGE_WRITE
460 #define __S011	PAGE_WRITE
461 #define __S100	PAGE_READ
462 #define __S101	PAGE_READ
463 #define __S110	PAGE_WRITE
464 #define __S111	PAGE_WRITE
465 
466 /*
467  * Segment entry (large page) protection definitions.
468  */
469 #define SEGMENT_NONE	__pgprot(_SEGMENT_ENTRY_INVALID | \
470 				 _SEGMENT_ENTRY_PROTECT)
471 #define SEGMENT_READ	__pgprot(_SEGMENT_ENTRY_PROTECT | \
472 				 _SEGMENT_ENTRY_READ)
473 #define SEGMENT_WRITE	__pgprot(_SEGMENT_ENTRY_READ | \
474 				 _SEGMENT_ENTRY_WRITE)
475 
476 static inline int mm_has_pgste(struct mm_struct *mm)
477 {
478 #ifdef CONFIG_PGSTE
479 	if (unlikely(mm->context.has_pgste))
480 		return 1;
481 #endif
482 	return 0;
483 }
484 
485 static inline int mm_use_skey(struct mm_struct *mm)
486 {
487 #ifdef CONFIG_PGSTE
488 	if (mm->context.use_skey)
489 		return 1;
490 #endif
491 	return 0;
492 }
493 
494 /*
495  * pgd/pmd/pte query functions
496  */
497 #ifndef CONFIG_64BIT
498 
499 static inline int pgd_present(pgd_t pgd) { return 1; }
500 static inline int pgd_none(pgd_t pgd)    { return 0; }
501 static inline int pgd_bad(pgd_t pgd)     { return 0; }
502 
503 static inline int pud_present(pud_t pud) { return 1; }
504 static inline int pud_none(pud_t pud)	 { return 0; }
505 static inline int pud_large(pud_t pud)	 { return 0; }
506 static inline int pud_bad(pud_t pud)	 { return 0; }
507 
508 #else /* CONFIG_64BIT */
509 
510 static inline int pgd_present(pgd_t pgd)
511 {
512 	if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2)
513 		return 1;
514 	return (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) != 0UL;
515 }
516 
517 static inline int pgd_none(pgd_t pgd)
518 {
519 	if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2)
520 		return 0;
521 	return (pgd_val(pgd) & _REGION_ENTRY_INVALID) != 0UL;
522 }
523 
524 static inline int pgd_bad(pgd_t pgd)
525 {
526 	/*
527 	 * With dynamic page table levels the pgd can be a region table
528 	 * entry or a segment table entry. Check for the bit that are
529 	 * invalid for either table entry.
530 	 */
531 	unsigned long mask =
532 		~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INVALID &
533 		~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH;
534 	return (pgd_val(pgd) & mask) != 0;
535 }
536 
537 static inline int pud_present(pud_t pud)
538 {
539 	if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3)
540 		return 1;
541 	return (pud_val(pud) & _REGION_ENTRY_ORIGIN) != 0UL;
542 }
543 
544 static inline int pud_none(pud_t pud)
545 {
546 	if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3)
547 		return 0;
548 	return (pud_val(pud) & _REGION_ENTRY_INVALID) != 0UL;
549 }
550 
551 static inline int pud_large(pud_t pud)
552 {
553 	if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) != _REGION_ENTRY_TYPE_R3)
554 		return 0;
555 	return !!(pud_val(pud) & _REGION3_ENTRY_LARGE);
556 }
557 
558 static inline int pud_bad(pud_t pud)
559 {
560 	/*
561 	 * With dynamic page table levels the pud can be a region table
562 	 * entry or a segment table entry. Check for the bit that are
563 	 * invalid for either table entry.
564 	 */
565 	unsigned long mask =
566 		~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INVALID &
567 		~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH;
568 	return (pud_val(pud) & mask) != 0;
569 }
570 
571 #endif /* CONFIG_64BIT */
572 
573 static inline int pmd_present(pmd_t pmd)
574 {
575 	return pmd_val(pmd) != _SEGMENT_ENTRY_INVALID;
576 }
577 
578 static inline int pmd_none(pmd_t pmd)
579 {
580 	return pmd_val(pmd) == _SEGMENT_ENTRY_INVALID;
581 }
582 
583 static inline int pmd_large(pmd_t pmd)
584 {
585 	return (pmd_val(pmd) & _SEGMENT_ENTRY_LARGE) != 0;
586 }
587 
588 static inline int pmd_pfn(pmd_t pmd)
589 {
590 	unsigned long origin_mask;
591 
592 	origin_mask = _SEGMENT_ENTRY_ORIGIN;
593 	if (pmd_large(pmd))
594 		origin_mask = _SEGMENT_ENTRY_ORIGIN_LARGE;
595 	return (pmd_val(pmd) & origin_mask) >> PAGE_SHIFT;
596 }
597 
598 static inline int pmd_bad(pmd_t pmd)
599 {
600 	if (pmd_large(pmd))
601 		return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS_LARGE) != 0;
602 	return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS) != 0;
603 }
604 
605 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
606 extern void pmdp_splitting_flush(struct vm_area_struct *vma,
607 				 unsigned long addr, pmd_t *pmdp);
608 
609 #define  __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
610 extern int pmdp_set_access_flags(struct vm_area_struct *vma,
611 				 unsigned long address, pmd_t *pmdp,
612 				 pmd_t entry, int dirty);
613 
614 #define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
615 extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
616 				  unsigned long address, pmd_t *pmdp);
617 
618 #define __HAVE_ARCH_PMD_WRITE
619 static inline int pmd_write(pmd_t pmd)
620 {
621 	return (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) != 0;
622 }
623 
624 static inline int pmd_dirty(pmd_t pmd)
625 {
626 	int dirty = 1;
627 	if (pmd_large(pmd))
628 		dirty = (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) != 0;
629 	return dirty;
630 }
631 
632 static inline int pmd_young(pmd_t pmd)
633 {
634 	int young = 1;
635 	if (pmd_large(pmd))
636 		young = (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) != 0;
637 	return young;
638 }
639 
640 static inline int pte_present(pte_t pte)
641 {
642 	/* Bit pattern: (pte & 0x001) == 0x001 */
643 	return (pte_val(pte) & _PAGE_PRESENT) != 0;
644 }
645 
646 static inline int pte_none(pte_t pte)
647 {
648 	/* Bit pattern: pte == 0x400 */
649 	return pte_val(pte) == _PAGE_INVALID;
650 }
651 
652 static inline int pte_swap(pte_t pte)
653 {
654 	/* Bit pattern: (pte & 0x603) == 0x402 */
655 	return (pte_val(pte) & (_PAGE_INVALID | _PAGE_PROTECT |
656 				_PAGE_TYPE | _PAGE_PRESENT))
657 		== (_PAGE_INVALID | _PAGE_TYPE);
658 }
659 
660 static inline int pte_file(pte_t pte)
661 {
662 	/* Bit pattern: (pte & 0x601) == 0x600 */
663 	return (pte_val(pte) & (_PAGE_INVALID | _PAGE_PROTECT | _PAGE_PRESENT))
664 		== (_PAGE_INVALID | _PAGE_PROTECT);
665 }
666 
667 static inline int pte_special(pte_t pte)
668 {
669 	return (pte_val(pte) & _PAGE_SPECIAL);
670 }
671 
672 #define __HAVE_ARCH_PTE_SAME
673 static inline int pte_same(pte_t a, pte_t b)
674 {
675 	return pte_val(a) == pte_val(b);
676 }
677 
678 static inline pgste_t pgste_get_lock(pte_t *ptep)
679 {
680 	unsigned long new = 0;
681 #ifdef CONFIG_PGSTE
682 	unsigned long old;
683 
684 	preempt_disable();
685 	asm(
686 		"	lg	%0,%2\n"
687 		"0:	lgr	%1,%0\n"
688 		"	nihh	%0,0xff7f\n"	/* clear PCL bit in old */
689 		"	oihh	%1,0x0080\n"	/* set PCL bit in new */
690 		"	csg	%0,%1,%2\n"
691 		"	jl	0b\n"
692 		: "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
693 		: "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
694 #endif
695 	return __pgste(new);
696 }
697 
698 static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
699 {
700 #ifdef CONFIG_PGSTE
701 	asm(
702 		"	nihh	%1,0xff7f\n"	/* clear PCL bit */
703 		"	stg	%1,%0\n"
704 		: "=Q" (ptep[PTRS_PER_PTE])
705 		: "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
706 		: "cc", "memory");
707 	preempt_enable();
708 #endif
709 }
710 
711 static inline pgste_t pgste_get(pte_t *ptep)
712 {
713 	unsigned long pgste = 0;
714 #ifdef CONFIG_PGSTE
715 	pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
716 #endif
717 	return __pgste(pgste);
718 }
719 
720 static inline void pgste_set(pte_t *ptep, pgste_t pgste)
721 {
722 #ifdef CONFIG_PGSTE
723 	*(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
724 #endif
725 }
726 
727 static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste,
728 				       struct mm_struct *mm)
729 {
730 #ifdef CONFIG_PGSTE
731 	unsigned long address, bits, skey;
732 
733 	if (!mm_use_skey(mm) || pte_val(*ptep) & _PAGE_INVALID)
734 		return pgste;
735 	address = pte_val(*ptep) & PAGE_MASK;
736 	skey = (unsigned long) page_get_storage_key(address);
737 	bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
738 	/* Transfer page changed & referenced bit to guest bits in pgste */
739 	pgste_val(pgste) |= bits << 48;		/* GR bit & GC bit */
740 	/* Copy page access key and fetch protection bit to pgste */
741 	pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
742 	pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
743 #endif
744 	return pgste;
745 
746 }
747 
748 static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
749 				 struct mm_struct *mm)
750 {
751 #ifdef CONFIG_PGSTE
752 	unsigned long address;
753 	unsigned long nkey;
754 
755 	if (!mm_use_skey(mm) || pte_val(entry) & _PAGE_INVALID)
756 		return;
757 	VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
758 	address = pte_val(entry) & PAGE_MASK;
759 	/*
760 	 * Set page access key and fetch protection bit from pgste.
761 	 * The guest C/R information is still in the PGSTE, set real
762 	 * key C/R to 0.
763 	 */
764 	nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
765 	nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
766 	page_set_storage_key(address, nkey, 0);
767 #endif
768 }
769 
770 static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
771 {
772 	if ((pte_val(entry) & _PAGE_PRESENT) &&
773 	    (pte_val(entry) & _PAGE_WRITE) &&
774 	    !(pte_val(entry) & _PAGE_INVALID)) {
775 		if (!MACHINE_HAS_ESOP) {
776 			/*
777 			 * Without enhanced suppression-on-protection force
778 			 * the dirty bit on for all writable ptes.
779 			 */
780 			pte_val(entry) |= _PAGE_DIRTY;
781 			pte_val(entry) &= ~_PAGE_PROTECT;
782 		}
783 		if (!(pte_val(entry) & _PAGE_PROTECT))
784 			/* This pte allows write access, set user-dirty */
785 			pgste_val(pgste) |= PGSTE_UC_BIT;
786 	}
787 	*ptep = entry;
788 	return pgste;
789 }
790 
791 /**
792  * struct gmap_struct - guest address space
793  * @crst_list: list of all crst tables used in the guest address space
794  * @mm: pointer to the parent mm_struct
795  * @guest_to_host: radix tree with guest to host address translation
796  * @host_to_guest: radix tree with pointer to segment table entries
797  * @guest_table_lock: spinlock to protect all entries in the guest page table
798  * @table: pointer to the page directory
799  * @asce: address space control element for gmap page table
800  * @pfault_enabled: defines if pfaults are applicable for the guest
801  */
802 struct gmap {
803 	struct list_head list;
804 	struct list_head crst_list;
805 	struct mm_struct *mm;
806 	struct radix_tree_root guest_to_host;
807 	struct radix_tree_root host_to_guest;
808 	spinlock_t guest_table_lock;
809 	unsigned long *table;
810 	unsigned long asce;
811 	unsigned long asce_end;
812 	void *private;
813 	bool pfault_enabled;
814 };
815 
816 /**
817  * struct gmap_notifier - notify function block for page invalidation
818  * @notifier_call: address of callback function
819  */
820 struct gmap_notifier {
821 	struct list_head list;
822 	void (*notifier_call)(struct gmap *gmap, unsigned long gaddr);
823 };
824 
825 struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit);
826 void gmap_free(struct gmap *gmap);
827 void gmap_enable(struct gmap *gmap);
828 void gmap_disable(struct gmap *gmap);
829 int gmap_map_segment(struct gmap *gmap, unsigned long from,
830 		     unsigned long to, unsigned long len);
831 int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
832 unsigned long __gmap_translate(struct gmap *, unsigned long gaddr);
833 unsigned long gmap_translate(struct gmap *, unsigned long gaddr);
834 int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr);
835 int gmap_fault(struct gmap *, unsigned long gaddr, unsigned int fault_flags);
836 void gmap_discard(struct gmap *, unsigned long from, unsigned long to);
837 void __gmap_zap(struct gmap *, unsigned long gaddr);
838 bool gmap_test_and_clear_dirty(unsigned long address, struct gmap *);
839 
840 
841 void gmap_register_ipte_notifier(struct gmap_notifier *);
842 void gmap_unregister_ipte_notifier(struct gmap_notifier *);
843 int gmap_ipte_notify(struct gmap *, unsigned long start, unsigned long len);
844 void gmap_do_ipte_notify(struct mm_struct *, unsigned long addr, pte_t *);
845 
846 static inline pgste_t pgste_ipte_notify(struct mm_struct *mm,
847 					unsigned long addr,
848 					pte_t *ptep, pgste_t pgste)
849 {
850 #ifdef CONFIG_PGSTE
851 	if (pgste_val(pgste) & PGSTE_IN_BIT) {
852 		pgste_val(pgste) &= ~PGSTE_IN_BIT;
853 		gmap_do_ipte_notify(mm, addr, ptep);
854 	}
855 #endif
856 	return pgste;
857 }
858 
859 /*
860  * Certain architectures need to do special things when PTEs
861  * within a page table are directly modified.  Thus, the following
862  * hook is made available.
863  */
864 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
865 			      pte_t *ptep, pte_t entry)
866 {
867 	pgste_t pgste;
868 
869 	if (mm_has_pgste(mm)) {
870 		pgste = pgste_get_lock(ptep);
871 		pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
872 		pgste_set_key(ptep, pgste, entry, mm);
873 		pgste = pgste_set_pte(ptep, pgste, entry);
874 		pgste_set_unlock(ptep, pgste);
875 	} else {
876 		if (!(pte_val(entry) & _PAGE_INVALID) && MACHINE_HAS_EDAT1)
877 			pte_val(entry) |= _PAGE_CO;
878 		*ptep = entry;
879 	}
880 }
881 
882 /*
883  * query functions pte_write/pte_dirty/pte_young only work if
884  * pte_present() is true. Undefined behaviour if not..
885  */
886 static inline int pte_write(pte_t pte)
887 {
888 	return (pte_val(pte) & _PAGE_WRITE) != 0;
889 }
890 
891 static inline int pte_dirty(pte_t pte)
892 {
893 	return (pte_val(pte) & _PAGE_DIRTY) != 0;
894 }
895 
896 static inline int pte_young(pte_t pte)
897 {
898 	return (pte_val(pte) & _PAGE_YOUNG) != 0;
899 }
900 
901 #define __HAVE_ARCH_PTE_UNUSED
902 static inline int pte_unused(pte_t pte)
903 {
904 	return pte_val(pte) & _PAGE_UNUSED;
905 }
906 
907 /*
908  * pgd/pmd/pte modification functions
909  */
910 
911 static inline void pgd_clear(pgd_t *pgd)
912 {
913 #ifdef CONFIG_64BIT
914 	if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
915 		pgd_val(*pgd) = _REGION2_ENTRY_EMPTY;
916 #endif
917 }
918 
919 static inline void pud_clear(pud_t *pud)
920 {
921 #ifdef CONFIG_64BIT
922 	if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
923 		pud_val(*pud) = _REGION3_ENTRY_EMPTY;
924 #endif
925 }
926 
927 static inline void pmd_clear(pmd_t *pmdp)
928 {
929 	pmd_val(*pmdp) = _SEGMENT_ENTRY_INVALID;
930 }
931 
932 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
933 {
934 	pte_val(*ptep) = _PAGE_INVALID;
935 }
936 
937 /*
938  * The following pte modification functions only work if
939  * pte_present() is true. Undefined behaviour if not..
940  */
941 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
942 {
943 	pte_val(pte) &= _PAGE_CHG_MASK;
944 	pte_val(pte) |= pgprot_val(newprot);
945 	/*
946 	 * newprot for PAGE_NONE, PAGE_READ and PAGE_WRITE has the
947 	 * invalid bit set, clear it again for readable, young pages
948 	 */
949 	if ((pte_val(pte) & _PAGE_YOUNG) && (pte_val(pte) & _PAGE_READ))
950 		pte_val(pte) &= ~_PAGE_INVALID;
951 	/*
952 	 * newprot for PAGE_READ and PAGE_WRITE has the page protection
953 	 * bit set, clear it again for writable, dirty pages
954 	 */
955 	if ((pte_val(pte) & _PAGE_DIRTY) && (pte_val(pte) & _PAGE_WRITE))
956 		pte_val(pte) &= ~_PAGE_PROTECT;
957 	return pte;
958 }
959 
960 static inline pte_t pte_wrprotect(pte_t pte)
961 {
962 	pte_val(pte) &= ~_PAGE_WRITE;
963 	pte_val(pte) |= _PAGE_PROTECT;
964 	return pte;
965 }
966 
967 static inline pte_t pte_mkwrite(pte_t pte)
968 {
969 	pte_val(pte) |= _PAGE_WRITE;
970 	if (pte_val(pte) & _PAGE_DIRTY)
971 		pte_val(pte) &= ~_PAGE_PROTECT;
972 	return pte;
973 }
974 
975 static inline pte_t pte_mkclean(pte_t pte)
976 {
977 	pte_val(pte) &= ~_PAGE_DIRTY;
978 	pte_val(pte) |= _PAGE_PROTECT;
979 	return pte;
980 }
981 
982 static inline pte_t pte_mkdirty(pte_t pte)
983 {
984 	pte_val(pte) |= _PAGE_DIRTY;
985 	if (pte_val(pte) & _PAGE_WRITE)
986 		pte_val(pte) &= ~_PAGE_PROTECT;
987 	return pte;
988 }
989 
990 static inline pte_t pte_mkold(pte_t pte)
991 {
992 	pte_val(pte) &= ~_PAGE_YOUNG;
993 	pte_val(pte) |= _PAGE_INVALID;
994 	return pte;
995 }
996 
997 static inline pte_t pte_mkyoung(pte_t pte)
998 {
999 	pte_val(pte) |= _PAGE_YOUNG;
1000 	if (pte_val(pte) & _PAGE_READ)
1001 		pte_val(pte) &= ~_PAGE_INVALID;
1002 	return pte;
1003 }
1004 
1005 static inline pte_t pte_mkspecial(pte_t pte)
1006 {
1007 	pte_val(pte) |= _PAGE_SPECIAL;
1008 	return pte;
1009 }
1010 
1011 #ifdef CONFIG_HUGETLB_PAGE
1012 static inline pte_t pte_mkhuge(pte_t pte)
1013 {
1014 	pte_val(pte) |= _PAGE_LARGE;
1015 	return pte;
1016 }
1017 #endif
1018 
1019 static inline void __ptep_ipte(unsigned long address, pte_t *ptep)
1020 {
1021 	unsigned long pto = (unsigned long) ptep;
1022 
1023 #ifndef CONFIG_64BIT
1024 	/* pto in ESA mode must point to the start of the segment table */
1025 	pto &= 0x7ffffc00;
1026 #endif
1027 	/* Invalidation + global TLB flush for the pte */
1028 	asm volatile(
1029 		"	ipte	%2,%3"
1030 		: "=m" (*ptep) : "m" (*ptep), "a" (pto), "a" (address));
1031 }
1032 
1033 static inline void __ptep_ipte_local(unsigned long address, pte_t *ptep)
1034 {
1035 	unsigned long pto = (unsigned long) ptep;
1036 
1037 #ifndef CONFIG_64BIT
1038 	/* pto in ESA mode must point to the start of the segment table */
1039 	pto &= 0x7ffffc00;
1040 #endif
1041 	/* Invalidation + local TLB flush for the pte */
1042 	asm volatile(
1043 		"	.insn rrf,0xb2210000,%2,%3,0,1"
1044 		: "=m" (*ptep) : "m" (*ptep), "a" (pto), "a" (address));
1045 }
1046 
1047 static inline void ptep_flush_direct(struct mm_struct *mm,
1048 				     unsigned long address, pte_t *ptep)
1049 {
1050 	int active, count;
1051 
1052 	if (pte_val(*ptep) & _PAGE_INVALID)
1053 		return;
1054 	active = (mm == current->active_mm) ? 1 : 0;
1055 	count = atomic_add_return(0x10000, &mm->context.attach_count);
1056 	if (MACHINE_HAS_TLB_LC && (count & 0xffff) <= active &&
1057 	    cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
1058 		__ptep_ipte_local(address, ptep);
1059 	else
1060 		__ptep_ipte(address, ptep);
1061 	atomic_sub(0x10000, &mm->context.attach_count);
1062 }
1063 
1064 static inline void ptep_flush_lazy(struct mm_struct *mm,
1065 				   unsigned long address, pte_t *ptep)
1066 {
1067 	int active, count;
1068 
1069 	if (pte_val(*ptep) & _PAGE_INVALID)
1070 		return;
1071 	active = (mm == current->active_mm) ? 1 : 0;
1072 	count = atomic_add_return(0x10000, &mm->context.attach_count);
1073 	if ((count & 0xffff) <= active) {
1074 		pte_val(*ptep) |= _PAGE_INVALID;
1075 		mm->context.flush_mm = 1;
1076 	} else
1077 		__ptep_ipte(address, ptep);
1078 	atomic_sub(0x10000, &mm->context.attach_count);
1079 }
1080 
1081 /*
1082  * Get (and clear) the user dirty bit for a pte.
1083  */
1084 static inline int ptep_test_and_clear_user_dirty(struct mm_struct *mm,
1085 						 unsigned long addr,
1086 						 pte_t *ptep)
1087 {
1088 	pgste_t pgste;
1089 	pte_t pte;
1090 	int dirty;
1091 
1092 	if (!mm_has_pgste(mm))
1093 		return 0;
1094 	pgste = pgste_get_lock(ptep);
1095 	dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
1096 	pgste_val(pgste) &= ~PGSTE_UC_BIT;
1097 	pte = *ptep;
1098 	if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
1099 		pgste = pgste_ipte_notify(mm, addr, ptep, pgste);
1100 		__ptep_ipte(addr, ptep);
1101 		if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
1102 			pte_val(pte) |= _PAGE_PROTECT;
1103 		else
1104 			pte_val(pte) |= _PAGE_INVALID;
1105 		*ptep = pte;
1106 	}
1107 	pgste_set_unlock(ptep, pgste);
1108 	return dirty;
1109 }
1110 
1111 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
1112 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
1113 					    unsigned long addr, pte_t *ptep)
1114 {
1115 	pgste_t pgste;
1116 	pte_t pte, oldpte;
1117 	int young;
1118 
1119 	if (mm_has_pgste(vma->vm_mm)) {
1120 		pgste = pgste_get_lock(ptep);
1121 		pgste = pgste_ipte_notify(vma->vm_mm, addr, ptep, pgste);
1122 	}
1123 
1124 	oldpte = pte = *ptep;
1125 	ptep_flush_direct(vma->vm_mm, addr, ptep);
1126 	young = pte_young(pte);
1127 	pte = pte_mkold(pte);
1128 
1129 	if (mm_has_pgste(vma->vm_mm)) {
1130 		pgste = pgste_update_all(&oldpte, pgste, vma->vm_mm);
1131 		pgste = pgste_set_pte(ptep, pgste, pte);
1132 		pgste_set_unlock(ptep, pgste);
1133 	} else
1134 		*ptep = pte;
1135 
1136 	return young;
1137 }
1138 
1139 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
1140 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
1141 					 unsigned long address, pte_t *ptep)
1142 {
1143 	return ptep_test_and_clear_young(vma, address, ptep);
1144 }
1145 
1146 /*
1147  * This is hard to understand. ptep_get_and_clear and ptep_clear_flush
1148  * both clear the TLB for the unmapped pte. The reason is that
1149  * ptep_get_and_clear is used in common code (e.g. change_pte_range)
1150  * to modify an active pte. The sequence is
1151  *   1) ptep_get_and_clear
1152  *   2) set_pte_at
1153  *   3) flush_tlb_range
1154  * On s390 the tlb needs to get flushed with the modification of the pte
1155  * if the pte is active. The only way how this can be implemented is to
1156  * have ptep_get_and_clear do the tlb flush. In exchange flush_tlb_range
1157  * is a nop.
1158  */
1159 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1160 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
1161 				       unsigned long address, pte_t *ptep)
1162 {
1163 	pgste_t pgste;
1164 	pte_t pte;
1165 
1166 	if (mm_has_pgste(mm)) {
1167 		pgste = pgste_get_lock(ptep);
1168 		pgste = pgste_ipte_notify(mm, address, ptep, pgste);
1169 	}
1170 
1171 	pte = *ptep;
1172 	ptep_flush_lazy(mm, address, ptep);
1173 	pte_val(*ptep) = _PAGE_INVALID;
1174 
1175 	if (mm_has_pgste(mm)) {
1176 		pgste = pgste_update_all(&pte, pgste, mm);
1177 		pgste_set_unlock(ptep, pgste);
1178 	}
1179 	return pte;
1180 }
1181 
1182 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
1183 static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
1184 					   unsigned long address,
1185 					   pte_t *ptep)
1186 {
1187 	pgste_t pgste;
1188 	pte_t pte;
1189 
1190 	if (mm_has_pgste(mm)) {
1191 		pgste = pgste_get_lock(ptep);
1192 		pgste_ipte_notify(mm, address, ptep, pgste);
1193 	}
1194 
1195 	pte = *ptep;
1196 	ptep_flush_lazy(mm, address, ptep);
1197 
1198 	if (mm_has_pgste(mm)) {
1199 		pgste = pgste_update_all(&pte, pgste, mm);
1200 		pgste_set(ptep, pgste);
1201 	}
1202 	return pte;
1203 }
1204 
1205 static inline void ptep_modify_prot_commit(struct mm_struct *mm,
1206 					   unsigned long address,
1207 					   pte_t *ptep, pte_t pte)
1208 {
1209 	pgste_t pgste;
1210 
1211 	if (mm_has_pgste(mm)) {
1212 		pgste = pgste_get(ptep);
1213 		pgste_set_key(ptep, pgste, pte, mm);
1214 		pgste = pgste_set_pte(ptep, pgste, pte);
1215 		pgste_set_unlock(ptep, pgste);
1216 	} else
1217 		*ptep = pte;
1218 }
1219 
1220 #define __HAVE_ARCH_PTEP_CLEAR_FLUSH
1221 static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
1222 				     unsigned long address, pte_t *ptep)
1223 {
1224 	pgste_t pgste;
1225 	pte_t pte;
1226 
1227 	if (mm_has_pgste(vma->vm_mm)) {
1228 		pgste = pgste_get_lock(ptep);
1229 		pgste = pgste_ipte_notify(vma->vm_mm, address, ptep, pgste);
1230 	}
1231 
1232 	pte = *ptep;
1233 	ptep_flush_direct(vma->vm_mm, address, ptep);
1234 	pte_val(*ptep) = _PAGE_INVALID;
1235 
1236 	if (mm_has_pgste(vma->vm_mm)) {
1237 		if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
1238 		    _PGSTE_GPS_USAGE_UNUSED)
1239 			pte_val(pte) |= _PAGE_UNUSED;
1240 		pgste = pgste_update_all(&pte, pgste, vma->vm_mm);
1241 		pgste_set_unlock(ptep, pgste);
1242 	}
1243 	return pte;
1244 }
1245 
1246 /*
1247  * The batched pte unmap code uses ptep_get_and_clear_full to clear the
1248  * ptes. Here an optimization is possible. tlb_gather_mmu flushes all
1249  * tlbs of an mm if it can guarantee that the ptes of the mm_struct
1250  * cannot be accessed while the batched unmap is running. In this case
1251  * full==1 and a simple pte_clear is enough. See tlb.h.
1252  */
1253 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
1254 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
1255 					    unsigned long address,
1256 					    pte_t *ptep, int full)
1257 {
1258 	pgste_t pgste;
1259 	pte_t pte;
1260 
1261 	if (!full && mm_has_pgste(mm)) {
1262 		pgste = pgste_get_lock(ptep);
1263 		pgste = pgste_ipte_notify(mm, address, ptep, pgste);
1264 	}
1265 
1266 	pte = *ptep;
1267 	if (!full)
1268 		ptep_flush_lazy(mm, address, ptep);
1269 	pte_val(*ptep) = _PAGE_INVALID;
1270 
1271 	if (!full && mm_has_pgste(mm)) {
1272 		pgste = pgste_update_all(&pte, pgste, mm);
1273 		pgste_set_unlock(ptep, pgste);
1274 	}
1275 	return pte;
1276 }
1277 
1278 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1279 static inline pte_t ptep_set_wrprotect(struct mm_struct *mm,
1280 				       unsigned long address, pte_t *ptep)
1281 {
1282 	pgste_t pgste;
1283 	pte_t pte = *ptep;
1284 
1285 	if (pte_write(pte)) {
1286 		if (mm_has_pgste(mm)) {
1287 			pgste = pgste_get_lock(ptep);
1288 			pgste = pgste_ipte_notify(mm, address, ptep, pgste);
1289 		}
1290 
1291 		ptep_flush_lazy(mm, address, ptep);
1292 		pte = pte_wrprotect(pte);
1293 
1294 		if (mm_has_pgste(mm)) {
1295 			pgste = pgste_set_pte(ptep, pgste, pte);
1296 			pgste_set_unlock(ptep, pgste);
1297 		} else
1298 			*ptep = pte;
1299 	}
1300 	return pte;
1301 }
1302 
1303 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1304 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
1305 					unsigned long address, pte_t *ptep,
1306 					pte_t entry, int dirty)
1307 {
1308 	pgste_t pgste;
1309 
1310 	if (pte_same(*ptep, entry))
1311 		return 0;
1312 	if (mm_has_pgste(vma->vm_mm)) {
1313 		pgste = pgste_get_lock(ptep);
1314 		pgste = pgste_ipte_notify(vma->vm_mm, address, ptep, pgste);
1315 	}
1316 
1317 	ptep_flush_direct(vma->vm_mm, address, ptep);
1318 
1319 	if (mm_has_pgste(vma->vm_mm)) {
1320 		pgste_set_key(ptep, pgste, entry, vma->vm_mm);
1321 		pgste = pgste_set_pte(ptep, pgste, entry);
1322 		pgste_set_unlock(ptep, pgste);
1323 	} else
1324 		*ptep = entry;
1325 	return 1;
1326 }
1327 
1328 /*
1329  * Conversion functions: convert a page and protection to a page entry,
1330  * and a page entry and page directory to the page they refer to.
1331  */
1332 static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
1333 {
1334 	pte_t __pte;
1335 	pte_val(__pte) = physpage + pgprot_val(pgprot);
1336 	return pte_mkyoung(__pte);
1337 }
1338 
1339 static inline pte_t mk_pte(struct page *page, pgprot_t pgprot)
1340 {
1341 	unsigned long physpage = page_to_phys(page);
1342 	pte_t __pte = mk_pte_phys(physpage, pgprot);
1343 
1344 	if (pte_write(__pte) && PageDirty(page))
1345 		__pte = pte_mkdirty(__pte);
1346 	return __pte;
1347 }
1348 
1349 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
1350 #define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
1351 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
1352 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
1353 
1354 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
1355 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
1356 
1357 #ifndef CONFIG_64BIT
1358 
1359 #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
1360 #define pud_deref(pmd) ({ BUG(); 0UL; })
1361 #define pgd_deref(pmd) ({ BUG(); 0UL; })
1362 
1363 #define pud_offset(pgd, address) ((pud_t *) pgd)
1364 #define pmd_offset(pud, address) ((pmd_t *) pud + pmd_index(address))
1365 
1366 #else /* CONFIG_64BIT */
1367 
1368 #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
1369 #define pud_deref(pud) (pud_val(pud) & _REGION_ENTRY_ORIGIN)
1370 #define pgd_deref(pgd) (pgd_val(pgd) & _REGION_ENTRY_ORIGIN)
1371 
1372 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address)
1373 {
1374 	pud_t *pud = (pud_t *) pgd;
1375 	if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
1376 		pud = (pud_t *) pgd_deref(*pgd);
1377 	return pud  + pud_index(address);
1378 }
1379 
1380 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
1381 {
1382 	pmd_t *pmd = (pmd_t *) pud;
1383 	if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
1384 		pmd = (pmd_t *) pud_deref(*pud);
1385 	return pmd + pmd_index(address);
1386 }
1387 
1388 #endif /* CONFIG_64BIT */
1389 
1390 #define pfn_pte(pfn,pgprot) mk_pte_phys(__pa((pfn) << PAGE_SHIFT),(pgprot))
1391 #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
1392 #define pte_page(x) pfn_to_page(pte_pfn(x))
1393 
1394 #define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd))
1395 
1396 /* Find an entry in the lowest level page table.. */
1397 #define pte_offset(pmd, addr) ((pte_t *) pmd_deref(*(pmd)) + pte_index(addr))
1398 #define pte_offset_kernel(pmd, address) pte_offset(pmd,address)
1399 #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
1400 #define pte_unmap(pte) do { } while (0)
1401 
1402 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE)
1403 static inline unsigned long massage_pgprot_pmd(pgprot_t pgprot)
1404 {
1405 	/*
1406 	 * pgprot is PAGE_NONE, PAGE_READ, or PAGE_WRITE (see __Pxxx / __Sxxx)
1407 	 * Convert to segment table entry format.
1408 	 */
1409 	if (pgprot_val(pgprot) == pgprot_val(PAGE_NONE))
1410 		return pgprot_val(SEGMENT_NONE);
1411 	if (pgprot_val(pgprot) == pgprot_val(PAGE_READ))
1412 		return pgprot_val(SEGMENT_READ);
1413 	return pgprot_val(SEGMENT_WRITE);
1414 }
1415 
1416 static inline pmd_t pmd_wrprotect(pmd_t pmd)
1417 {
1418 	pmd_val(pmd) &= ~_SEGMENT_ENTRY_WRITE;
1419 	pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
1420 	return pmd;
1421 }
1422 
1423 static inline pmd_t pmd_mkwrite(pmd_t pmd)
1424 {
1425 	pmd_val(pmd) |= _SEGMENT_ENTRY_WRITE;
1426 	if (pmd_large(pmd) && !(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY))
1427 		return pmd;
1428 	pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
1429 	return pmd;
1430 }
1431 
1432 static inline pmd_t pmd_mkclean(pmd_t pmd)
1433 {
1434 	if (pmd_large(pmd)) {
1435 		pmd_val(pmd) &= ~_SEGMENT_ENTRY_DIRTY;
1436 		pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
1437 	}
1438 	return pmd;
1439 }
1440 
1441 static inline pmd_t pmd_mkdirty(pmd_t pmd)
1442 {
1443 	if (pmd_large(pmd)) {
1444 		pmd_val(pmd) |= _SEGMENT_ENTRY_DIRTY;
1445 		if (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE)
1446 			pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
1447 	}
1448 	return pmd;
1449 }
1450 
1451 static inline pmd_t pmd_mkyoung(pmd_t pmd)
1452 {
1453 	if (pmd_large(pmd)) {
1454 		pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
1455 		if (pmd_val(pmd) & _SEGMENT_ENTRY_READ)
1456 			pmd_val(pmd) &= ~_SEGMENT_ENTRY_INVALID;
1457 	}
1458 	return pmd;
1459 }
1460 
1461 static inline pmd_t pmd_mkold(pmd_t pmd)
1462 {
1463 	if (pmd_large(pmd)) {
1464 		pmd_val(pmd) &= ~_SEGMENT_ENTRY_YOUNG;
1465 		pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
1466 	}
1467 	return pmd;
1468 }
1469 
1470 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
1471 {
1472 	if (pmd_large(pmd)) {
1473 		pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN_LARGE |
1474 			_SEGMENT_ENTRY_DIRTY | _SEGMENT_ENTRY_YOUNG |
1475 			_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_SPLIT;
1476 		pmd_val(pmd) |= massage_pgprot_pmd(newprot);
1477 		if (!(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY))
1478 			pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
1479 		if (!(pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG))
1480 			pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
1481 		return pmd;
1482 	}
1483 	pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN;
1484 	pmd_val(pmd) |= massage_pgprot_pmd(newprot);
1485 	return pmd;
1486 }
1487 
1488 static inline pmd_t mk_pmd_phys(unsigned long physpage, pgprot_t pgprot)
1489 {
1490 	pmd_t __pmd;
1491 	pmd_val(__pmd) = physpage + massage_pgprot_pmd(pgprot);
1492 	return __pmd;
1493 }
1494 
1495 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLB_PAGE */
1496 
1497 static inline void __pmdp_csp(pmd_t *pmdp)
1498 {
1499 	register unsigned long reg2 asm("2") = pmd_val(*pmdp);
1500 	register unsigned long reg3 asm("3") = pmd_val(*pmdp) |
1501 					       _SEGMENT_ENTRY_INVALID;
1502 	register unsigned long reg4 asm("4") = ((unsigned long) pmdp) + 5;
1503 
1504 	asm volatile(
1505 		"	csp %1,%3"
1506 		: "=m" (*pmdp)
1507 		: "d" (reg2), "d" (reg3), "d" (reg4), "m" (*pmdp) : "cc");
1508 }
1509 
1510 static inline void __pmdp_idte(unsigned long address, pmd_t *pmdp)
1511 {
1512 	unsigned long sto;
1513 
1514 	sto = (unsigned long) pmdp - pmd_index(address) * sizeof(pmd_t);
1515 	asm volatile(
1516 		"	.insn	rrf,0xb98e0000,%2,%3,0,0"
1517 		: "=m" (*pmdp)
1518 		: "m" (*pmdp), "a" (sto), "a" ((address & HPAGE_MASK))
1519 		: "cc" );
1520 }
1521 
1522 static inline void __pmdp_idte_local(unsigned long address, pmd_t *pmdp)
1523 {
1524 	unsigned long sto;
1525 
1526 	sto = (unsigned long) pmdp - pmd_index(address) * sizeof(pmd_t);
1527 	asm volatile(
1528 		"	.insn	rrf,0xb98e0000,%2,%3,0,1"
1529 		: "=m" (*pmdp)
1530 		: "m" (*pmdp), "a" (sto), "a" ((address & HPAGE_MASK))
1531 		: "cc" );
1532 }
1533 
1534 static inline void pmdp_flush_direct(struct mm_struct *mm,
1535 				     unsigned long address, pmd_t *pmdp)
1536 {
1537 	int active, count;
1538 
1539 	if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
1540 		return;
1541 	if (!MACHINE_HAS_IDTE) {
1542 		__pmdp_csp(pmdp);
1543 		return;
1544 	}
1545 	active = (mm == current->active_mm) ? 1 : 0;
1546 	count = atomic_add_return(0x10000, &mm->context.attach_count);
1547 	if (MACHINE_HAS_TLB_LC && (count & 0xffff) <= active &&
1548 	    cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
1549 		__pmdp_idte_local(address, pmdp);
1550 	else
1551 		__pmdp_idte(address, pmdp);
1552 	atomic_sub(0x10000, &mm->context.attach_count);
1553 }
1554 
1555 static inline void pmdp_flush_lazy(struct mm_struct *mm,
1556 				   unsigned long address, pmd_t *pmdp)
1557 {
1558 	int active, count;
1559 
1560 	if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
1561 		return;
1562 	active = (mm == current->active_mm) ? 1 : 0;
1563 	count = atomic_add_return(0x10000, &mm->context.attach_count);
1564 	if ((count & 0xffff) <= active) {
1565 		pmd_val(*pmdp) |= _SEGMENT_ENTRY_INVALID;
1566 		mm->context.flush_mm = 1;
1567 	} else if (MACHINE_HAS_IDTE)
1568 		__pmdp_idte(address, pmdp);
1569 	else
1570 		__pmdp_csp(pmdp);
1571 	atomic_sub(0x10000, &mm->context.attach_count);
1572 }
1573 
1574 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1575 
1576 #define __HAVE_ARCH_PGTABLE_DEPOSIT
1577 extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
1578 				       pgtable_t pgtable);
1579 
1580 #define __HAVE_ARCH_PGTABLE_WITHDRAW
1581 extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
1582 
1583 static inline int pmd_trans_splitting(pmd_t pmd)
1584 {
1585 	return (pmd_val(pmd) & _SEGMENT_ENTRY_LARGE) &&
1586 		(pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT);
1587 }
1588 
1589 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
1590 			      pmd_t *pmdp, pmd_t entry)
1591 {
1592 	*pmdp = entry;
1593 }
1594 
1595 static inline pmd_t pmd_mkhuge(pmd_t pmd)
1596 {
1597 	pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
1598 	pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
1599 	pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
1600 	return pmd;
1601 }
1602 
1603 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1604 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
1605 					    unsigned long address, pmd_t *pmdp)
1606 {
1607 	pmd_t pmd;
1608 
1609 	pmd = *pmdp;
1610 	pmdp_flush_direct(vma->vm_mm, address, pmdp);
1611 	*pmdp = pmd_mkold(pmd);
1612 	return pmd_young(pmd);
1613 }
1614 
1615 #define __HAVE_ARCH_PMDP_GET_AND_CLEAR
1616 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
1617 				       unsigned long address, pmd_t *pmdp)
1618 {
1619 	pmd_t pmd = *pmdp;
1620 
1621 	pmdp_flush_direct(mm, address, pmdp);
1622 	pmd_clear(pmdp);
1623 	return pmd;
1624 }
1625 
1626 #define __HAVE_ARCH_PMDP_CLEAR_FLUSH
1627 static inline pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
1628 				     unsigned long address, pmd_t *pmdp)
1629 {
1630 	return pmdp_get_and_clear(vma->vm_mm, address, pmdp);
1631 }
1632 
1633 #define __HAVE_ARCH_PMDP_INVALIDATE
1634 static inline void pmdp_invalidate(struct vm_area_struct *vma,
1635 				   unsigned long address, pmd_t *pmdp)
1636 {
1637 	pmdp_flush_direct(vma->vm_mm, address, pmdp);
1638 }
1639 
1640 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1641 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1642 				      unsigned long address, pmd_t *pmdp)
1643 {
1644 	pmd_t pmd = *pmdp;
1645 
1646 	if (pmd_write(pmd)) {
1647 		pmdp_flush_direct(mm, address, pmdp);
1648 		set_pmd_at(mm, address, pmdp, pmd_wrprotect(pmd));
1649 	}
1650 }
1651 
1652 #define pfn_pmd(pfn, pgprot)	mk_pmd_phys(__pa((pfn) << PAGE_SHIFT), (pgprot))
1653 #define mk_pmd(page, pgprot)	pfn_pmd(page_to_pfn(page), (pgprot))
1654 
1655 static inline int pmd_trans_huge(pmd_t pmd)
1656 {
1657 	return pmd_val(pmd) & _SEGMENT_ENTRY_LARGE;
1658 }
1659 
1660 static inline int has_transparent_hugepage(void)
1661 {
1662 	return MACHINE_HAS_HPAGE ? 1 : 0;
1663 }
1664 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1665 
1666 /*
1667  * 31 bit swap entry format:
1668  * A page-table entry has some bits we have to treat in a special way.
1669  * Bits 0, 20 and bit 23 have to be zero, otherwise an specification
1670  * exception will occur instead of a page translation exception. The
1671  * specifiation exception has the bad habit not to store necessary
1672  * information in the lowcore.
1673  * Bits 21, 22, 30 and 31 are used to indicate the page type.
1674  * A swap pte is indicated by bit pattern (pte & 0x603) == 0x402
1675  * This leaves the bits 1-19 and bits 24-29 to store type and offset.
1676  * We use the 5 bits from 25-29 for the type and the 20 bits from 1-19
1677  * plus 24 for the offset.
1678  * 0|     offset        |0110|o|type |00|
1679  * 0 0000000001111111111 2222 2 22222 33
1680  * 0 1234567890123456789 0123 4 56789 01
1681  *
1682  * 64 bit swap entry format:
1683  * A page-table entry has some bits we have to treat in a special way.
1684  * Bits 52 and bit 55 have to be zero, otherwise an specification
1685  * exception will occur instead of a page translation exception. The
1686  * specifiation exception has the bad habit not to store necessary
1687  * information in the lowcore.
1688  * Bits 53, 54, 62 and 63 are used to indicate the page type.
1689  * A swap pte is indicated by bit pattern (pte & 0x603) == 0x402
1690  * This leaves the bits 0-51 and bits 56-61 to store type and offset.
1691  * We use the 5 bits from 57-61 for the type and the 53 bits from 0-51
1692  * plus 56 for the offset.
1693  * |                      offset                        |0110|o|type |00|
1694  *  0000000000111111111122222222223333333333444444444455 5555 5 55566 66
1695  *  0123456789012345678901234567890123456789012345678901 2345 6 78901 23
1696  */
1697 #ifndef CONFIG_64BIT
1698 #define __SWP_OFFSET_MASK (~0UL >> 12)
1699 #else
1700 #define __SWP_OFFSET_MASK (~0UL >> 11)
1701 #endif
1702 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
1703 {
1704 	pte_t pte;
1705 	offset &= __SWP_OFFSET_MASK;
1706 	pte_val(pte) = _PAGE_INVALID | _PAGE_TYPE | ((type & 0x1f) << 2) |
1707 		((offset & 1UL) << 7) | ((offset & ~1UL) << 11);
1708 	return pte;
1709 }
1710 
1711 #define __swp_type(entry)	(((entry).val >> 2) & 0x1f)
1712 #define __swp_offset(entry)	(((entry).val >> 11) | (((entry).val >> 7) & 1))
1713 #define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) })
1714 
1715 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1716 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
1717 
1718 #ifndef CONFIG_64BIT
1719 # define PTE_FILE_MAX_BITS	26
1720 #else /* CONFIG_64BIT */
1721 # define PTE_FILE_MAX_BITS	59
1722 #endif /* CONFIG_64BIT */
1723 
1724 #define pte_to_pgoff(__pte) \
1725 	((((__pte).pte >> 12) << 7) + (((__pte).pte >> 1) & 0x7f))
1726 
1727 #define pgoff_to_pte(__off) \
1728 	((pte_t) { ((((__off) & 0x7f) << 1) + (((__off) >> 7) << 12)) \
1729 		   | _PAGE_INVALID | _PAGE_PROTECT })
1730 
1731 #endif /* !__ASSEMBLY__ */
1732 
1733 #define kern_addr_valid(addr)   (1)
1734 
1735 extern int vmem_add_mapping(unsigned long start, unsigned long size);
1736 extern int vmem_remove_mapping(unsigned long start, unsigned long size);
1737 extern int s390_enable_sie(void);
1738 extern void s390_enable_skey(void);
1739 
1740 /*
1741  * No page table caches to initialise
1742  */
1743 static inline void pgtable_cache_init(void) { }
1744 static inline void check_pgt_cache(void) { }
1745 
1746 #include <asm-generic/pgtable.h>
1747 
1748 #endif /* _S390_PAGE_H */
1749