xref: /linux/arch/s390/include/asm/pgtable.h (revision 615f2e5c531bc57d5a190f321d697988e950ae4d)
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 <asm/bug.h>
34 #include <asm/page.h>
35 
36 extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096)));
37 extern void paging_init(void);
38 extern void vmem_map_init(void);
39 
40 /*
41  * The S390 doesn't have any external MMU info: the kernel page
42  * tables contain all the necessary information.
43  */
44 #define update_mmu_cache(vma, address, ptep)     do { } while (0)
45 #define update_mmu_cache_pmd(vma, address, ptep) do { } while (0)
46 
47 /*
48  * ZERO_PAGE is a global shared page that is always zero; used
49  * for zero-mapped memory areas etc..
50  */
51 
52 extern unsigned long empty_zero_page;
53 extern unsigned long zero_page_mask;
54 
55 #define ZERO_PAGE(vaddr) \
56 	(virt_to_page((void *)(empty_zero_page + \
57 	 (((unsigned long)(vaddr)) &zero_page_mask))))
58 #define __HAVE_COLOR_ZERO_PAGE
59 
60 #endif /* !__ASSEMBLY__ */
61 
62 /*
63  * PMD_SHIFT determines the size of the area a second-level page
64  * table can map
65  * PGDIR_SHIFT determines what a third-level page table entry can map
66  */
67 #ifndef CONFIG_64BIT
68 # define PMD_SHIFT	20
69 # define PUD_SHIFT	20
70 # define PGDIR_SHIFT	20
71 #else /* CONFIG_64BIT */
72 # define PMD_SHIFT	20
73 # define PUD_SHIFT	31
74 # define PGDIR_SHIFT	42
75 #endif /* CONFIG_64BIT */
76 
77 #define PMD_SIZE        (1UL << PMD_SHIFT)
78 #define PMD_MASK        (~(PMD_SIZE-1))
79 #define PUD_SIZE	(1UL << PUD_SHIFT)
80 #define PUD_MASK	(~(PUD_SIZE-1))
81 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
82 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
83 
84 /*
85  * entries per page directory level: the S390 is two-level, so
86  * we don't really have any PMD directory physically.
87  * for S390 segment-table entries are combined to one PGD
88  * that leads to 1024 pte per pgd
89  */
90 #define PTRS_PER_PTE	256
91 #ifndef CONFIG_64BIT
92 #define PTRS_PER_PMD	1
93 #define PTRS_PER_PUD	1
94 #else /* CONFIG_64BIT */
95 #define PTRS_PER_PMD	2048
96 #define PTRS_PER_PUD	2048
97 #endif /* CONFIG_64BIT */
98 #define PTRS_PER_PGD	2048
99 
100 #define FIRST_USER_ADDRESS  0
101 
102 #define pte_ERROR(e) \
103 	printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e))
104 #define pmd_ERROR(e) \
105 	printk("%s:%d: bad pmd %p.\n", __FILE__, __LINE__, (void *) pmd_val(e))
106 #define pud_ERROR(e) \
107 	printk("%s:%d: bad pud %p.\n", __FILE__, __LINE__, (void *) pud_val(e))
108 #define pgd_ERROR(e) \
109 	printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) pgd_val(e))
110 
111 #ifndef __ASSEMBLY__
112 /*
113  * The vmalloc and module area will always be on the topmost area of the kernel
114  * mapping. We reserve 96MB (31bit) / 128GB (64bit) for vmalloc and modules.
115  * On 64 bit kernels we have a 2GB area at the top of the vmalloc area where
116  * modules will reside. That makes sure that inter module branches always
117  * happen without trampolines and in addition the placement within a 2GB frame
118  * is branch prediction unit friendly.
119  */
120 extern unsigned long VMALLOC_START;
121 extern unsigned long VMALLOC_END;
122 extern struct page *vmemmap;
123 
124 #define VMEM_MAX_PHYS ((unsigned long) vmemmap)
125 
126 #ifdef CONFIG_64BIT
127 extern unsigned long MODULES_VADDR;
128 extern unsigned long MODULES_END;
129 #define MODULES_VADDR	MODULES_VADDR
130 #define MODULES_END	MODULES_END
131 #define MODULES_LEN	(1UL << 31)
132 #endif
133 
134 /*
135  * A 31 bit pagetable entry of S390 has following format:
136  *  |   PFRA          |    |  OS  |
137  * 0                   0IP0
138  * 00000000001111111111222222222233
139  * 01234567890123456789012345678901
140  *
141  * I Page-Invalid Bit:    Page is not available for address-translation
142  * P Page-Protection Bit: Store access not possible for page
143  *
144  * A 31 bit segmenttable entry of S390 has following format:
145  *  |   P-table origin      |  |PTL
146  * 0                         IC
147  * 00000000001111111111222222222233
148  * 01234567890123456789012345678901
149  *
150  * I Segment-Invalid Bit:    Segment is not available for address-translation
151  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
152  * PTL Page-Table-Length:    Page-table length (PTL+1*16 entries -> up to 256)
153  *
154  * The 31 bit segmenttable origin of S390 has following format:
155  *
156  *  |S-table origin   |     | STL |
157  * X                   **GPS
158  * 00000000001111111111222222222233
159  * 01234567890123456789012345678901
160  *
161  * X Space-Switch event:
162  * G Segment-Invalid Bit:     *
163  * P Private-Space Bit:       Segment is not private (PoP 3-30)
164  * S Storage-Alteration:
165  * STL Segment-Table-Length:  Segment-table length (STL+1*16 entries -> up to 2048)
166  *
167  * A 64 bit pagetable entry of S390 has following format:
168  * |			 PFRA			      |0IPC|  OS  |
169  * 0000000000111111111122222222223333333333444444444455555555556666
170  * 0123456789012345678901234567890123456789012345678901234567890123
171  *
172  * I Page-Invalid Bit:    Page is not available for address-translation
173  * P Page-Protection Bit: Store access not possible for page
174  * C Change-bit override: HW is not required to set change bit
175  *
176  * A 64 bit segmenttable entry of S390 has following format:
177  * |        P-table origin                              |      TT
178  * 0000000000111111111122222222223333333333444444444455555555556666
179  * 0123456789012345678901234567890123456789012345678901234567890123
180  *
181  * I Segment-Invalid Bit:    Segment is not available for address-translation
182  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
183  * P Page-Protection Bit: Store access not possible for page
184  * TT Type 00
185  *
186  * A 64 bit region table entry of S390 has following format:
187  * |        S-table origin                             |   TF  TTTL
188  * 0000000000111111111122222222223333333333444444444455555555556666
189  * 0123456789012345678901234567890123456789012345678901234567890123
190  *
191  * I Segment-Invalid Bit:    Segment is not available for address-translation
192  * TT Type 01
193  * TF
194  * TL Table length
195  *
196  * The 64 bit regiontable origin of S390 has following format:
197  * |      region table origon                          |       DTTL
198  * 0000000000111111111122222222223333333333444444444455555555556666
199  * 0123456789012345678901234567890123456789012345678901234567890123
200  *
201  * X Space-Switch event:
202  * G Segment-Invalid Bit:
203  * P Private-Space Bit:
204  * S Storage-Alteration:
205  * R Real space
206  * TL Table-Length:
207  *
208  * A storage key has the following format:
209  * | ACC |F|R|C|0|
210  *  0   3 4 5 6 7
211  * ACC: access key
212  * F  : fetch protection bit
213  * R  : referenced bit
214  * C  : changed bit
215  */
216 
217 /* Hardware bits in the page table entry */
218 #define _PAGE_CO	0x100		/* HW Change-bit override */
219 #define _PAGE_RO	0x200		/* HW read-only bit  */
220 #define _PAGE_INVALID	0x400		/* HW invalid bit    */
221 
222 /* Software bits in the page table entry */
223 #define _PAGE_SWT	0x001		/* SW pte type bit t */
224 #define _PAGE_SWX	0x002		/* SW pte type bit x */
225 #define _PAGE_SWC	0x004		/* SW pte changed bit */
226 #define _PAGE_SWR	0x008		/* SW pte referenced bit */
227 #define _PAGE_SWW	0x010		/* SW pte write bit */
228 #define _PAGE_SPECIAL	0x020		/* SW associated with special page */
229 #define __HAVE_ARCH_PTE_SPECIAL
230 
231 /* Set of bits not changed in pte_modify */
232 #define _PAGE_CHG_MASK		(PAGE_MASK | _PAGE_SPECIAL | _PAGE_CO | \
233 				 _PAGE_SWC | _PAGE_SWR)
234 
235 /* Six different types of pages. */
236 #define _PAGE_TYPE_EMPTY	0x400
237 #define _PAGE_TYPE_NONE		0x401
238 #define _PAGE_TYPE_SWAP		0x403
239 #define _PAGE_TYPE_FILE		0x601	/* bit 0x002 is used for offset !! */
240 #define _PAGE_TYPE_RO		0x200
241 #define _PAGE_TYPE_RW		0x000
242 
243 /*
244  * Only four types for huge pages, using the invalid bit and protection bit
245  * of a segment table entry.
246  */
247 #define _HPAGE_TYPE_EMPTY	0x020	/* _SEGMENT_ENTRY_INV */
248 #define _HPAGE_TYPE_NONE	0x220
249 #define _HPAGE_TYPE_RO		0x200	/* _SEGMENT_ENTRY_RO  */
250 #define _HPAGE_TYPE_RW		0x000
251 
252 /*
253  * PTE type bits are rather complicated. handle_pte_fault uses pte_present,
254  * pte_none and pte_file to find out the pte type WITHOUT holding the page
255  * table lock. ptep_clear_flush on the other hand uses ptep_clear_flush to
256  * invalidate a given pte. ipte sets the hw invalid bit and clears all tlbs
257  * for the page. The page table entry is set to _PAGE_TYPE_EMPTY afterwards.
258  * This change is done while holding the lock, but the intermediate step
259  * of a previously valid pte with the hw invalid bit set can be observed by
260  * handle_pte_fault. That makes it necessary that all valid pte types with
261  * the hw invalid bit set must be distinguishable from the four pte types
262  * empty, none, swap and file.
263  *
264  *			irxt  ipte  irxt
265  * _PAGE_TYPE_EMPTY	1000   ->   1000
266  * _PAGE_TYPE_NONE	1001   ->   1001
267  * _PAGE_TYPE_SWAP	1011   ->   1011
268  * _PAGE_TYPE_FILE	11?1   ->   11?1
269  * _PAGE_TYPE_RO	0100   ->   1100
270  * _PAGE_TYPE_RW	0000   ->   1000
271  *
272  * pte_none is true for bits combinations 1000, 1010, 1100, 1110
273  * pte_present is true for bits combinations 0000, 0010, 0100, 0110, 1001
274  * pte_file is true for bits combinations 1101, 1111
275  * swap pte is 1011 and 0001, 0011, 0101, 0111 are invalid.
276  */
277 
278 #ifndef CONFIG_64BIT
279 
280 /* Bits in the segment table address-space-control-element */
281 #define _ASCE_SPACE_SWITCH	0x80000000UL	/* space switch event	    */
282 #define _ASCE_ORIGIN_MASK	0x7ffff000UL	/* segment table origin	    */
283 #define _ASCE_PRIVATE_SPACE	0x100	/* private space control	    */
284 #define _ASCE_ALT_EVENT		0x80	/* storage alteration event control */
285 #define _ASCE_TABLE_LENGTH	0x7f	/* 128 x 64 entries = 8k	    */
286 
287 /* Bits in the segment table entry */
288 #define _SEGMENT_ENTRY_ORIGIN	0x7fffffc0UL	/* page table origin	    */
289 #define _SEGMENT_ENTRY_RO	0x200	/* page protection bit		    */
290 #define _SEGMENT_ENTRY_INV	0x20	/* invalid segment table entry	    */
291 #define _SEGMENT_ENTRY_COMMON	0x10	/* common segment bit		    */
292 #define _SEGMENT_ENTRY_PTL	0x0f	/* page table length		    */
293 
294 #define _SEGMENT_ENTRY		(_SEGMENT_ENTRY_PTL)
295 #define _SEGMENT_ENTRY_EMPTY	(_SEGMENT_ENTRY_INV)
296 
297 /* Page status table bits for virtualization */
298 #define RCP_ACC_BITS	0xf0000000UL
299 #define RCP_FP_BIT	0x08000000UL
300 #define RCP_PCL_BIT	0x00800000UL
301 #define RCP_HR_BIT	0x00400000UL
302 #define RCP_HC_BIT	0x00200000UL
303 #define RCP_GR_BIT	0x00040000UL
304 #define RCP_GC_BIT	0x00020000UL
305 
306 /* User dirty / referenced bit for KVM's migration feature */
307 #define KVM_UR_BIT	0x00008000UL
308 #define KVM_UC_BIT	0x00004000UL
309 
310 #else /* CONFIG_64BIT */
311 
312 /* Bits in the segment/region table address-space-control-element */
313 #define _ASCE_ORIGIN		~0xfffUL/* segment table origin		    */
314 #define _ASCE_PRIVATE_SPACE	0x100	/* private space control	    */
315 #define _ASCE_ALT_EVENT		0x80	/* storage alteration event control */
316 #define _ASCE_SPACE_SWITCH	0x40	/* space switch event		    */
317 #define _ASCE_REAL_SPACE	0x20	/* real space control		    */
318 #define _ASCE_TYPE_MASK		0x0c	/* asce table type mask		    */
319 #define _ASCE_TYPE_REGION1	0x0c	/* region first table type	    */
320 #define _ASCE_TYPE_REGION2	0x08	/* region second table type	    */
321 #define _ASCE_TYPE_REGION3	0x04	/* region third table type	    */
322 #define _ASCE_TYPE_SEGMENT	0x00	/* segment table type		    */
323 #define _ASCE_TABLE_LENGTH	0x03	/* region table length		    */
324 
325 /* Bits in the region table entry */
326 #define _REGION_ENTRY_ORIGIN	~0xfffUL/* region/segment table origin	    */
327 #define _REGION_ENTRY_RO	0x200	/* region protection bit	    */
328 #define _REGION_ENTRY_INV	0x20	/* invalid region table entry	    */
329 #define _REGION_ENTRY_TYPE_MASK	0x0c	/* region/segment table type mask   */
330 #define _REGION_ENTRY_TYPE_R1	0x0c	/* region first table type	    */
331 #define _REGION_ENTRY_TYPE_R2	0x08	/* region second table type	    */
332 #define _REGION_ENTRY_TYPE_R3	0x04	/* region third table type	    */
333 #define _REGION_ENTRY_LENGTH	0x03	/* region third length		    */
334 
335 #define _REGION1_ENTRY		(_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_LENGTH)
336 #define _REGION1_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INV)
337 #define _REGION2_ENTRY		(_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_LENGTH)
338 #define _REGION2_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INV)
339 #define _REGION3_ENTRY		(_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_LENGTH)
340 #define _REGION3_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INV)
341 
342 #define _REGION3_ENTRY_LARGE	0x400	/* RTTE-format control, large page  */
343 
344 /* Bits in the segment table entry */
345 #define _SEGMENT_ENTRY_ORIGIN	~0x7ffUL/* segment table origin		    */
346 #define _SEGMENT_ENTRY_RO	0x200	/* page protection bit		    */
347 #define _SEGMENT_ENTRY_INV	0x20	/* invalid segment table entry	    */
348 
349 #define _SEGMENT_ENTRY		(0)
350 #define _SEGMENT_ENTRY_EMPTY	(_SEGMENT_ENTRY_INV)
351 
352 #define _SEGMENT_ENTRY_LARGE	0x400	/* STE-format control, large page   */
353 #define _SEGMENT_ENTRY_CO	0x100	/* change-recording override   */
354 #define _SEGMENT_ENTRY_SPLIT_BIT 0	/* THP splitting bit number */
355 #define _SEGMENT_ENTRY_SPLIT	(1UL << _SEGMENT_ENTRY_SPLIT_BIT)
356 
357 /* Set of bits not changed in pmd_modify */
358 #define _SEGMENT_CHG_MASK	(_SEGMENT_ENTRY_ORIGIN | _SEGMENT_ENTRY_LARGE \
359 				 | _SEGMENT_ENTRY_SPLIT | _SEGMENT_ENTRY_CO)
360 
361 /* Page status table bits for virtualization */
362 #define RCP_ACC_BITS	0xf000000000000000UL
363 #define RCP_FP_BIT	0x0800000000000000UL
364 #define RCP_PCL_BIT	0x0080000000000000UL
365 #define RCP_HR_BIT	0x0040000000000000UL
366 #define RCP_HC_BIT	0x0020000000000000UL
367 #define RCP_GR_BIT	0x0004000000000000UL
368 #define RCP_GC_BIT	0x0002000000000000UL
369 
370 /* User dirty / referenced bit for KVM's migration feature */
371 #define KVM_UR_BIT	0x0000800000000000UL
372 #define KVM_UC_BIT	0x0000400000000000UL
373 
374 #endif /* CONFIG_64BIT */
375 
376 /*
377  * A user page table pointer has the space-switch-event bit, the
378  * private-space-control bit and the storage-alteration-event-control
379  * bit set. A kernel page table pointer doesn't need them.
380  */
381 #define _ASCE_USER_BITS		(_ASCE_SPACE_SWITCH | _ASCE_PRIVATE_SPACE | \
382 				 _ASCE_ALT_EVENT)
383 
384 /*
385  * Page protection definitions.
386  */
387 #define PAGE_NONE	__pgprot(_PAGE_TYPE_NONE)
388 #define PAGE_RO		__pgprot(_PAGE_TYPE_RO)
389 #define PAGE_RW		__pgprot(_PAGE_TYPE_RO | _PAGE_SWW)
390 #define PAGE_RWC	__pgprot(_PAGE_TYPE_RW | _PAGE_SWW | _PAGE_SWC)
391 
392 #define PAGE_KERNEL	PAGE_RWC
393 #define PAGE_SHARED	PAGE_KERNEL
394 #define PAGE_COPY	PAGE_RO
395 
396 /*
397  * On s390 the page table entry has an invalid bit and a read-only bit.
398  * Read permission implies execute permission and write permission
399  * implies read permission.
400  */
401          /*xwr*/
402 #define __P000	PAGE_NONE
403 #define __P001	PAGE_RO
404 #define __P010	PAGE_RO
405 #define __P011	PAGE_RO
406 #define __P100	PAGE_RO
407 #define __P101	PAGE_RO
408 #define __P110	PAGE_RO
409 #define __P111	PAGE_RO
410 
411 #define __S000	PAGE_NONE
412 #define __S001	PAGE_RO
413 #define __S010	PAGE_RW
414 #define __S011	PAGE_RW
415 #define __S100	PAGE_RO
416 #define __S101	PAGE_RO
417 #define __S110	PAGE_RW
418 #define __S111	PAGE_RW
419 
420 static inline int mm_exclusive(struct mm_struct *mm)
421 {
422 	return likely(mm == current->active_mm &&
423 		      atomic_read(&mm->context.attach_count) <= 1);
424 }
425 
426 static inline int mm_has_pgste(struct mm_struct *mm)
427 {
428 #ifdef CONFIG_PGSTE
429 	if (unlikely(mm->context.has_pgste))
430 		return 1;
431 #endif
432 	return 0;
433 }
434 /*
435  * pgd/pmd/pte query functions
436  */
437 #ifndef CONFIG_64BIT
438 
439 static inline int pgd_present(pgd_t pgd) { return 1; }
440 static inline int pgd_none(pgd_t pgd)    { return 0; }
441 static inline int pgd_bad(pgd_t pgd)     { return 0; }
442 
443 static inline int pud_present(pud_t pud) { return 1; }
444 static inline int pud_none(pud_t pud)	 { return 0; }
445 static inline int pud_large(pud_t pud)	 { return 0; }
446 static inline int pud_bad(pud_t pud)	 { return 0; }
447 
448 #else /* CONFIG_64BIT */
449 
450 static inline int pgd_present(pgd_t pgd)
451 {
452 	if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2)
453 		return 1;
454 	return (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) != 0UL;
455 }
456 
457 static inline int pgd_none(pgd_t pgd)
458 {
459 	if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2)
460 		return 0;
461 	return (pgd_val(pgd) & _REGION_ENTRY_INV) != 0UL;
462 }
463 
464 static inline int pgd_bad(pgd_t pgd)
465 {
466 	/*
467 	 * With dynamic page table levels the pgd can be a region table
468 	 * entry or a segment table entry. Check for the bit that are
469 	 * invalid for either table entry.
470 	 */
471 	unsigned long mask =
472 		~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INV &
473 		~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH;
474 	return (pgd_val(pgd) & mask) != 0;
475 }
476 
477 static inline int pud_present(pud_t pud)
478 {
479 	if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3)
480 		return 1;
481 	return (pud_val(pud) & _REGION_ENTRY_ORIGIN) != 0UL;
482 }
483 
484 static inline int pud_none(pud_t pud)
485 {
486 	if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3)
487 		return 0;
488 	return (pud_val(pud) & _REGION_ENTRY_INV) != 0UL;
489 }
490 
491 static inline int pud_large(pud_t pud)
492 {
493 	if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) != _REGION_ENTRY_TYPE_R3)
494 		return 0;
495 	return !!(pud_val(pud) & _REGION3_ENTRY_LARGE);
496 }
497 
498 static inline int pud_bad(pud_t pud)
499 {
500 	/*
501 	 * With dynamic page table levels the pud can be a region table
502 	 * entry or a segment table entry. Check for the bit that are
503 	 * invalid for either table entry.
504 	 */
505 	unsigned long mask =
506 		~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INV &
507 		~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH;
508 	return (pud_val(pud) & mask) != 0;
509 }
510 
511 #endif /* CONFIG_64BIT */
512 
513 static inline int pmd_present(pmd_t pmd)
514 {
515 	unsigned long mask = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO;
516 	return (pmd_val(pmd) & mask) == _HPAGE_TYPE_NONE ||
517 	       !(pmd_val(pmd) & _SEGMENT_ENTRY_INV);
518 }
519 
520 static inline int pmd_none(pmd_t pmd)
521 {
522 	return (pmd_val(pmd) & _SEGMENT_ENTRY_INV) &&
523 	       !(pmd_val(pmd) & _SEGMENT_ENTRY_RO);
524 }
525 
526 static inline int pmd_large(pmd_t pmd)
527 {
528 #ifdef CONFIG_64BIT
529 	return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
530 #else
531 	return 0;
532 #endif
533 }
534 
535 static inline int pmd_bad(pmd_t pmd)
536 {
537 	unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_SEGMENT_ENTRY_INV;
538 	return (pmd_val(pmd) & mask) != _SEGMENT_ENTRY;
539 }
540 
541 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
542 extern void pmdp_splitting_flush(struct vm_area_struct *vma,
543 				 unsigned long addr, pmd_t *pmdp);
544 
545 #define  __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
546 extern int pmdp_set_access_flags(struct vm_area_struct *vma,
547 				 unsigned long address, pmd_t *pmdp,
548 				 pmd_t entry, int dirty);
549 
550 #define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
551 extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
552 				  unsigned long address, pmd_t *pmdp);
553 
554 #define __HAVE_ARCH_PMD_WRITE
555 static inline int pmd_write(pmd_t pmd)
556 {
557 	return (pmd_val(pmd) & _SEGMENT_ENTRY_RO) == 0;
558 }
559 
560 static inline int pmd_young(pmd_t pmd)
561 {
562 	return 0;
563 }
564 
565 static inline int pte_none(pte_t pte)
566 {
567 	return (pte_val(pte) & _PAGE_INVALID) && !(pte_val(pte) & _PAGE_SWT);
568 }
569 
570 static inline int pte_present(pte_t pte)
571 {
572 	unsigned long mask = _PAGE_RO | _PAGE_INVALID | _PAGE_SWT | _PAGE_SWX;
573 	return (pte_val(pte) & mask) == _PAGE_TYPE_NONE ||
574 		(!(pte_val(pte) & _PAGE_INVALID) &&
575 		 !(pte_val(pte) & _PAGE_SWT));
576 }
577 
578 static inline int pte_file(pte_t pte)
579 {
580 	unsigned long mask = _PAGE_RO | _PAGE_INVALID | _PAGE_SWT;
581 	return (pte_val(pte) & mask) == _PAGE_TYPE_FILE;
582 }
583 
584 static inline int pte_special(pte_t pte)
585 {
586 	return (pte_val(pte) & _PAGE_SPECIAL);
587 }
588 
589 #define __HAVE_ARCH_PTE_SAME
590 static inline int pte_same(pte_t a, pte_t b)
591 {
592 	return pte_val(a) == pte_val(b);
593 }
594 
595 static inline pgste_t pgste_get_lock(pte_t *ptep)
596 {
597 	unsigned long new = 0;
598 #ifdef CONFIG_PGSTE
599 	unsigned long old;
600 
601 	preempt_disable();
602 	asm(
603 		"	lg	%0,%2\n"
604 		"0:	lgr	%1,%0\n"
605 		"	nihh	%0,0xff7f\n"	/* clear RCP_PCL_BIT in old */
606 		"	oihh	%1,0x0080\n"	/* set RCP_PCL_BIT in new */
607 		"	csg	%0,%1,%2\n"
608 		"	jl	0b\n"
609 		: "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
610 		: "Q" (ptep[PTRS_PER_PTE]) : "cc");
611 #endif
612 	return __pgste(new);
613 }
614 
615 static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
616 {
617 #ifdef CONFIG_PGSTE
618 	asm(
619 		"	nihh	%1,0xff7f\n"	/* clear RCP_PCL_BIT */
620 		"	stg	%1,%0\n"
621 		: "=Q" (ptep[PTRS_PER_PTE])
622 		: "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE]) : "cc");
623 	preempt_enable();
624 #endif
625 }
626 
627 static inline pgste_t pgste_update_all(pte_t *ptep, pgste_t pgste)
628 {
629 #ifdef CONFIG_PGSTE
630 	unsigned long address, bits;
631 	unsigned char skey;
632 
633 	if (!pte_present(*ptep))
634 		return pgste;
635 	address = pte_val(*ptep) & PAGE_MASK;
636 	skey = page_get_storage_key(address);
637 	bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
638 	/* Clear page changed & referenced bit in the storage key */
639 	if (bits & _PAGE_CHANGED)
640 		page_set_storage_key(address, skey ^ bits, 0);
641 	else if (bits)
642 		page_reset_referenced(address);
643 	/* Transfer page changed & referenced bit to guest bits in pgste */
644 	pgste_val(pgste) |= bits << 48;		/* RCP_GR_BIT & RCP_GC_BIT */
645 	/* Get host changed & referenced bits from pgste */
646 	bits |= (pgste_val(pgste) & (RCP_HR_BIT | RCP_HC_BIT)) >> 52;
647 	/* Transfer page changed & referenced bit to kvm user bits */
648 	pgste_val(pgste) |= bits << 45;		/* KVM_UR_BIT & KVM_UC_BIT */
649 	/* Clear relevant host bits in pgste. */
650 	pgste_val(pgste) &= ~(RCP_HR_BIT | RCP_HC_BIT);
651 	pgste_val(pgste) &= ~(RCP_ACC_BITS | RCP_FP_BIT);
652 	/* Copy page access key and fetch protection bit to pgste */
653 	pgste_val(pgste) |=
654 		(unsigned long) (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
655 	/* Transfer referenced bit to pte */
656 	pte_val(*ptep) |= (bits & _PAGE_REFERENCED) << 1;
657 #endif
658 	return pgste;
659 
660 }
661 
662 static inline pgste_t pgste_update_young(pte_t *ptep, pgste_t pgste)
663 {
664 #ifdef CONFIG_PGSTE
665 	int young;
666 
667 	if (!pte_present(*ptep))
668 		return pgste;
669 	/* Get referenced bit from storage key */
670 	young = page_reset_referenced(pte_val(*ptep) & PAGE_MASK);
671 	if (young)
672 		pgste_val(pgste) |= RCP_GR_BIT;
673 	/* Get host referenced bit from pgste */
674 	if (pgste_val(pgste) & RCP_HR_BIT) {
675 		pgste_val(pgste) &= ~RCP_HR_BIT;
676 		young = 1;
677 	}
678 	/* Transfer referenced bit to kvm user bits and pte */
679 	if (young) {
680 		pgste_val(pgste) |= KVM_UR_BIT;
681 		pte_val(*ptep) |= _PAGE_SWR;
682 	}
683 #endif
684 	return pgste;
685 }
686 
687 static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry)
688 {
689 #ifdef CONFIG_PGSTE
690 	unsigned long address;
691 	unsigned long okey, nkey;
692 
693 	if (!pte_present(entry))
694 		return;
695 	address = pte_val(entry) & PAGE_MASK;
696 	okey = nkey = page_get_storage_key(address);
697 	nkey &= ~(_PAGE_ACC_BITS | _PAGE_FP_BIT);
698 	/* Set page access key and fetch protection bit from pgste */
699 	nkey |= (pgste_val(pgste) & (RCP_ACC_BITS | RCP_FP_BIT)) >> 56;
700 	if (okey != nkey)
701 		page_set_storage_key(address, nkey, 0);
702 #endif
703 }
704 
705 static inline void pgste_set_pte(pte_t *ptep, pte_t entry)
706 {
707 	if (!MACHINE_HAS_ESOP && (pte_val(entry) & _PAGE_SWW)) {
708 		/*
709 		 * Without enhanced suppression-on-protection force
710 		 * the dirty bit on for all writable ptes.
711 		 */
712 		pte_val(entry) |= _PAGE_SWC;
713 		pte_val(entry) &= ~_PAGE_RO;
714 	}
715 	*ptep = entry;
716 }
717 
718 /**
719  * struct gmap_struct - guest address space
720  * @mm: pointer to the parent mm_struct
721  * @table: pointer to the page directory
722  * @asce: address space control element for gmap page table
723  * @crst_list: list of all crst tables used in the guest address space
724  */
725 struct gmap {
726 	struct list_head list;
727 	struct mm_struct *mm;
728 	unsigned long *table;
729 	unsigned long asce;
730 	struct list_head crst_list;
731 };
732 
733 /**
734  * struct gmap_rmap - reverse mapping for segment table entries
735  * @next: pointer to the next gmap_rmap structure in the list
736  * @entry: pointer to a segment table entry
737  */
738 struct gmap_rmap {
739 	struct list_head list;
740 	unsigned long *entry;
741 };
742 
743 /**
744  * struct gmap_pgtable - gmap information attached to a page table
745  * @vmaddr: address of the 1MB segment in the process virtual memory
746  * @mapper: list of segment table entries maping a page table
747  */
748 struct gmap_pgtable {
749 	unsigned long vmaddr;
750 	struct list_head mapper;
751 };
752 
753 struct gmap *gmap_alloc(struct mm_struct *mm);
754 void gmap_free(struct gmap *gmap);
755 void gmap_enable(struct gmap *gmap);
756 void gmap_disable(struct gmap *gmap);
757 int gmap_map_segment(struct gmap *gmap, unsigned long from,
758 		     unsigned long to, unsigned long length);
759 int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
760 unsigned long __gmap_fault(unsigned long address, struct gmap *);
761 unsigned long gmap_fault(unsigned long address, struct gmap *);
762 void gmap_discard(unsigned long from, unsigned long to, struct gmap *);
763 
764 /*
765  * Certain architectures need to do special things when PTEs
766  * within a page table are directly modified.  Thus, the following
767  * hook is made available.
768  */
769 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
770 			      pte_t *ptep, pte_t entry)
771 {
772 	pgste_t pgste;
773 
774 	if (mm_has_pgste(mm)) {
775 		pgste = pgste_get_lock(ptep);
776 		pgste_set_key(ptep, pgste, entry);
777 		pgste_set_pte(ptep, entry);
778 		pgste_set_unlock(ptep, pgste);
779 	} else {
780 		if (!(pte_val(entry) & _PAGE_INVALID) && MACHINE_HAS_EDAT1)
781 			pte_val(entry) |= _PAGE_CO;
782 		*ptep = entry;
783 	}
784 }
785 
786 /*
787  * query functions pte_write/pte_dirty/pte_young only work if
788  * pte_present() is true. Undefined behaviour if not..
789  */
790 static inline int pte_write(pte_t pte)
791 {
792 	return (pte_val(pte) & _PAGE_SWW) != 0;
793 }
794 
795 static inline int pte_dirty(pte_t pte)
796 {
797 	return (pte_val(pte) & _PAGE_SWC) != 0;
798 }
799 
800 static inline int pte_young(pte_t pte)
801 {
802 #ifdef CONFIG_PGSTE
803 	if (pte_val(pte) & _PAGE_SWR)
804 		return 1;
805 #endif
806 	return 0;
807 }
808 
809 /*
810  * pgd/pmd/pte modification functions
811  */
812 
813 static inline void pgd_clear(pgd_t *pgd)
814 {
815 #ifdef CONFIG_64BIT
816 	if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
817 		pgd_val(*pgd) = _REGION2_ENTRY_EMPTY;
818 #endif
819 }
820 
821 static inline void pud_clear(pud_t *pud)
822 {
823 #ifdef CONFIG_64BIT
824 	if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
825 		pud_val(*pud) = _REGION3_ENTRY_EMPTY;
826 #endif
827 }
828 
829 static inline void pmd_clear(pmd_t *pmdp)
830 {
831 	pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
832 }
833 
834 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
835 {
836 	pte_val(*ptep) = _PAGE_TYPE_EMPTY;
837 }
838 
839 /*
840  * The following pte modification functions only work if
841  * pte_present() is true. Undefined behaviour if not..
842  */
843 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
844 {
845 	pte_val(pte) &= _PAGE_CHG_MASK;
846 	pte_val(pte) |= pgprot_val(newprot);
847 	if ((pte_val(pte) & _PAGE_SWC) && (pte_val(pte) & _PAGE_SWW))
848 		pte_val(pte) &= ~_PAGE_RO;
849 	return pte;
850 }
851 
852 static inline pte_t pte_wrprotect(pte_t pte)
853 {
854 	pte_val(pte) &= ~_PAGE_SWW;
855 	/* Do not clobber _PAGE_TYPE_NONE pages!  */
856 	if (!(pte_val(pte) & _PAGE_INVALID))
857 		pte_val(pte) |= _PAGE_RO;
858 	return pte;
859 }
860 
861 static inline pte_t pte_mkwrite(pte_t pte)
862 {
863 	pte_val(pte) |= _PAGE_SWW;
864 	if (pte_val(pte) & _PAGE_SWC)
865 		pte_val(pte) &= ~_PAGE_RO;
866 	return pte;
867 }
868 
869 static inline pte_t pte_mkclean(pte_t pte)
870 {
871 	pte_val(pte) &= ~_PAGE_SWC;
872 	/* Do not clobber _PAGE_TYPE_NONE pages!  */
873 	if (!(pte_val(pte) & _PAGE_INVALID))
874 		pte_val(pte) |= _PAGE_RO;
875 	return pte;
876 }
877 
878 static inline pte_t pte_mkdirty(pte_t pte)
879 {
880 	pte_val(pte) |= _PAGE_SWC;
881 	if (pte_val(pte) & _PAGE_SWW)
882 		pte_val(pte) &= ~_PAGE_RO;
883 	return pte;
884 }
885 
886 static inline pte_t pte_mkold(pte_t pte)
887 {
888 #ifdef CONFIG_PGSTE
889 	pte_val(pte) &= ~_PAGE_SWR;
890 #endif
891 	return pte;
892 }
893 
894 static inline pte_t pte_mkyoung(pte_t pte)
895 {
896 	return pte;
897 }
898 
899 static inline pte_t pte_mkspecial(pte_t pte)
900 {
901 	pte_val(pte) |= _PAGE_SPECIAL;
902 	return pte;
903 }
904 
905 #ifdef CONFIG_HUGETLB_PAGE
906 static inline pte_t pte_mkhuge(pte_t pte)
907 {
908 	/*
909 	 * PROT_NONE needs to be remapped from the pte type to the ste type.
910 	 * The HW invalid bit is also different for pte and ste. The pte
911 	 * invalid bit happens to be the same as the ste _SEGMENT_ENTRY_LARGE
912 	 * bit, so we don't have to clear it.
913 	 */
914 	if (pte_val(pte) & _PAGE_INVALID) {
915 		if (pte_val(pte) & _PAGE_SWT)
916 			pte_val(pte) |= _HPAGE_TYPE_NONE;
917 		pte_val(pte) |= _SEGMENT_ENTRY_INV;
918 	}
919 	/*
920 	 * Clear SW pte bits, there are no SW bits in a segment table entry.
921 	 */
922 	pte_val(pte) &= ~(_PAGE_SWT | _PAGE_SWX | _PAGE_SWC |
923 			  _PAGE_SWR | _PAGE_SWW);
924 	/*
925 	 * Also set the change-override bit because we don't need dirty bit
926 	 * tracking for hugetlbfs pages.
927 	 */
928 	pte_val(pte) |= (_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_CO);
929 	return pte;
930 }
931 #endif
932 
933 /*
934  * Get (and clear) the user dirty bit for a pte.
935  */
936 static inline int ptep_test_and_clear_user_dirty(struct mm_struct *mm,
937 						 pte_t *ptep)
938 {
939 	pgste_t pgste;
940 	int dirty = 0;
941 
942 	if (mm_has_pgste(mm)) {
943 		pgste = pgste_get_lock(ptep);
944 		pgste = pgste_update_all(ptep, pgste);
945 		dirty = !!(pgste_val(pgste) & KVM_UC_BIT);
946 		pgste_val(pgste) &= ~KVM_UC_BIT;
947 		pgste_set_unlock(ptep, pgste);
948 		return dirty;
949 	}
950 	return dirty;
951 }
952 
953 /*
954  * Get (and clear) the user referenced bit for a pte.
955  */
956 static inline int ptep_test_and_clear_user_young(struct mm_struct *mm,
957 						 pte_t *ptep)
958 {
959 	pgste_t pgste;
960 	int young = 0;
961 
962 	if (mm_has_pgste(mm)) {
963 		pgste = pgste_get_lock(ptep);
964 		pgste = pgste_update_young(ptep, pgste);
965 		young = !!(pgste_val(pgste) & KVM_UR_BIT);
966 		pgste_val(pgste) &= ~KVM_UR_BIT;
967 		pgste_set_unlock(ptep, pgste);
968 	}
969 	return young;
970 }
971 
972 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
973 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
974 					    unsigned long addr, pte_t *ptep)
975 {
976 	pgste_t pgste;
977 	pte_t pte;
978 
979 	if (mm_has_pgste(vma->vm_mm)) {
980 		pgste = pgste_get_lock(ptep);
981 		pgste = pgste_update_young(ptep, pgste);
982 		pte = *ptep;
983 		*ptep = pte_mkold(pte);
984 		pgste_set_unlock(ptep, pgste);
985 		return pte_young(pte);
986 	}
987 	return 0;
988 }
989 
990 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
991 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
992 					 unsigned long address, pte_t *ptep)
993 {
994 	/* No need to flush TLB
995 	 * On s390 reference bits are in storage key and never in TLB
996 	 * With virtualization we handle the reference bit, without we
997 	 * we can simply return */
998 	return ptep_test_and_clear_young(vma, address, ptep);
999 }
1000 
1001 static inline void __ptep_ipte(unsigned long address, pte_t *ptep)
1002 {
1003 	if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1004 #ifndef CONFIG_64BIT
1005 		/* pto must point to the start of the segment table */
1006 		pte_t *pto = (pte_t *) (((unsigned long) ptep) & 0x7ffffc00);
1007 #else
1008 		/* ipte in zarch mode can do the math */
1009 		pte_t *pto = ptep;
1010 #endif
1011 		asm volatile(
1012 			"	ipte	%2,%3"
1013 			: "=m" (*ptep) : "m" (*ptep),
1014 			  "a" (pto), "a" (address));
1015 	}
1016 }
1017 
1018 /*
1019  * This is hard to understand. ptep_get_and_clear and ptep_clear_flush
1020  * both clear the TLB for the unmapped pte. The reason is that
1021  * ptep_get_and_clear is used in common code (e.g. change_pte_range)
1022  * to modify an active pte. The sequence is
1023  *   1) ptep_get_and_clear
1024  *   2) set_pte_at
1025  *   3) flush_tlb_range
1026  * On s390 the tlb needs to get flushed with the modification of the pte
1027  * if the pte is active. The only way how this can be implemented is to
1028  * have ptep_get_and_clear do the tlb flush. In exchange flush_tlb_range
1029  * is a nop.
1030  */
1031 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1032 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
1033 				       unsigned long address, pte_t *ptep)
1034 {
1035 	pgste_t pgste;
1036 	pte_t pte;
1037 
1038 	mm->context.flush_mm = 1;
1039 	if (mm_has_pgste(mm))
1040 		pgste = pgste_get_lock(ptep);
1041 
1042 	pte = *ptep;
1043 	if (!mm_exclusive(mm))
1044 		__ptep_ipte(address, ptep);
1045 	pte_val(*ptep) = _PAGE_TYPE_EMPTY;
1046 
1047 	if (mm_has_pgste(mm)) {
1048 		pgste = pgste_update_all(&pte, pgste);
1049 		pgste_set_unlock(ptep, pgste);
1050 	}
1051 	return pte;
1052 }
1053 
1054 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
1055 static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
1056 					   unsigned long address,
1057 					   pte_t *ptep)
1058 {
1059 	pte_t pte;
1060 
1061 	mm->context.flush_mm = 1;
1062 	if (mm_has_pgste(mm))
1063 		pgste_get_lock(ptep);
1064 
1065 	pte = *ptep;
1066 	if (!mm_exclusive(mm))
1067 		__ptep_ipte(address, ptep);
1068 	return pte;
1069 }
1070 
1071 static inline void ptep_modify_prot_commit(struct mm_struct *mm,
1072 					   unsigned long address,
1073 					   pte_t *ptep, pte_t pte)
1074 {
1075 	if (mm_has_pgste(mm)) {
1076 		pgste_set_pte(ptep, pte);
1077 		pgste_set_unlock(ptep, *(pgste_t *)(ptep + PTRS_PER_PTE));
1078 	} else
1079 		*ptep = pte;
1080 }
1081 
1082 #define __HAVE_ARCH_PTEP_CLEAR_FLUSH
1083 static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
1084 				     unsigned long address, pte_t *ptep)
1085 {
1086 	pgste_t pgste;
1087 	pte_t pte;
1088 
1089 	if (mm_has_pgste(vma->vm_mm))
1090 		pgste = pgste_get_lock(ptep);
1091 
1092 	pte = *ptep;
1093 	__ptep_ipte(address, ptep);
1094 	pte_val(*ptep) = _PAGE_TYPE_EMPTY;
1095 
1096 	if (mm_has_pgste(vma->vm_mm)) {
1097 		pgste = pgste_update_all(&pte, pgste);
1098 		pgste_set_unlock(ptep, pgste);
1099 	}
1100 	return pte;
1101 }
1102 
1103 /*
1104  * The batched pte unmap code uses ptep_get_and_clear_full to clear the
1105  * ptes. Here an optimization is possible. tlb_gather_mmu flushes all
1106  * tlbs of an mm if it can guarantee that the ptes of the mm_struct
1107  * cannot be accessed while the batched unmap is running. In this case
1108  * full==1 and a simple pte_clear is enough. See tlb.h.
1109  */
1110 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
1111 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
1112 					    unsigned long address,
1113 					    pte_t *ptep, int full)
1114 {
1115 	pgste_t pgste;
1116 	pte_t pte;
1117 
1118 	if (mm_has_pgste(mm))
1119 		pgste = pgste_get_lock(ptep);
1120 
1121 	pte = *ptep;
1122 	if (!full)
1123 		__ptep_ipte(address, ptep);
1124 	pte_val(*ptep) = _PAGE_TYPE_EMPTY;
1125 
1126 	if (mm_has_pgste(mm)) {
1127 		pgste = pgste_update_all(&pte, pgste);
1128 		pgste_set_unlock(ptep, pgste);
1129 	}
1130 	return pte;
1131 }
1132 
1133 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1134 static inline pte_t ptep_set_wrprotect(struct mm_struct *mm,
1135 				       unsigned long address, pte_t *ptep)
1136 {
1137 	pgste_t pgste;
1138 	pte_t pte = *ptep;
1139 
1140 	if (pte_write(pte)) {
1141 		mm->context.flush_mm = 1;
1142 		if (mm_has_pgste(mm))
1143 			pgste = pgste_get_lock(ptep);
1144 
1145 		if (!mm_exclusive(mm))
1146 			__ptep_ipte(address, ptep);
1147 		pte = pte_wrprotect(pte);
1148 
1149 		if (mm_has_pgste(mm)) {
1150 			pgste_set_pte(ptep, pte);
1151 			pgste_set_unlock(ptep, pgste);
1152 		} else
1153 			*ptep = pte;
1154 	}
1155 	return pte;
1156 }
1157 
1158 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1159 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
1160 					unsigned long address, pte_t *ptep,
1161 					pte_t entry, int dirty)
1162 {
1163 	pgste_t pgste;
1164 
1165 	if (pte_same(*ptep, entry))
1166 		return 0;
1167 	if (mm_has_pgste(vma->vm_mm))
1168 		pgste = pgste_get_lock(ptep);
1169 
1170 	__ptep_ipte(address, ptep);
1171 
1172 	if (mm_has_pgste(vma->vm_mm)) {
1173 		pgste_set_pte(ptep, entry);
1174 		pgste_set_unlock(ptep, pgste);
1175 	} else
1176 		*ptep = entry;
1177 	return 1;
1178 }
1179 
1180 /*
1181  * Conversion functions: convert a page and protection to a page entry,
1182  * and a page entry and page directory to the page they refer to.
1183  */
1184 static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
1185 {
1186 	pte_t __pte;
1187 	pte_val(__pte) = physpage + pgprot_val(pgprot);
1188 	return __pte;
1189 }
1190 
1191 static inline pte_t mk_pte(struct page *page, pgprot_t pgprot)
1192 {
1193 	unsigned long physpage = page_to_phys(page);
1194 	pte_t __pte = mk_pte_phys(physpage, pgprot);
1195 
1196 	if ((pte_val(__pte) & _PAGE_SWW) && PageDirty(page)) {
1197 		pte_val(__pte) |= _PAGE_SWC;
1198 		pte_val(__pte) &= ~_PAGE_RO;
1199 	}
1200 	return __pte;
1201 }
1202 
1203 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
1204 #define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
1205 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
1206 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
1207 
1208 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
1209 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
1210 
1211 #ifndef CONFIG_64BIT
1212 
1213 #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
1214 #define pud_deref(pmd) ({ BUG(); 0UL; })
1215 #define pgd_deref(pmd) ({ BUG(); 0UL; })
1216 
1217 #define pud_offset(pgd, address) ((pud_t *) pgd)
1218 #define pmd_offset(pud, address) ((pmd_t *) pud + pmd_index(address))
1219 
1220 #else /* CONFIG_64BIT */
1221 
1222 #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
1223 #define pud_deref(pud) (pud_val(pud) & _REGION_ENTRY_ORIGIN)
1224 #define pgd_deref(pgd) (pgd_val(pgd) & _REGION_ENTRY_ORIGIN)
1225 
1226 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address)
1227 {
1228 	pud_t *pud = (pud_t *) pgd;
1229 	if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
1230 		pud = (pud_t *) pgd_deref(*pgd);
1231 	return pud  + pud_index(address);
1232 }
1233 
1234 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
1235 {
1236 	pmd_t *pmd = (pmd_t *) pud;
1237 	if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
1238 		pmd = (pmd_t *) pud_deref(*pud);
1239 	return pmd + pmd_index(address);
1240 }
1241 
1242 #endif /* CONFIG_64BIT */
1243 
1244 #define pfn_pte(pfn,pgprot) mk_pte_phys(__pa((pfn) << PAGE_SHIFT),(pgprot))
1245 #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
1246 #define pte_page(x) pfn_to_page(pte_pfn(x))
1247 
1248 #define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
1249 
1250 /* Find an entry in the lowest level page table.. */
1251 #define pte_offset(pmd, addr) ((pte_t *) pmd_deref(*(pmd)) + pte_index(addr))
1252 #define pte_offset_kernel(pmd, address) pte_offset(pmd,address)
1253 #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
1254 #define pte_unmap(pte) do { } while (0)
1255 
1256 static inline void __pmd_idte(unsigned long address, pmd_t *pmdp)
1257 {
1258 	unsigned long sto = (unsigned long) pmdp -
1259 			    pmd_index(address) * sizeof(pmd_t);
1260 
1261 	if (!(pmd_val(*pmdp) & _SEGMENT_ENTRY_INV)) {
1262 		asm volatile(
1263 			"	.insn	rrf,0xb98e0000,%2,%3,0,0"
1264 			: "=m" (*pmdp)
1265 			: "m" (*pmdp), "a" (sto),
1266 			  "a" ((address & HPAGE_MASK))
1267 			: "cc"
1268 		);
1269 	}
1270 }
1271 
1272 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1273 
1274 #define SEGMENT_NONE	__pgprot(_HPAGE_TYPE_NONE)
1275 #define SEGMENT_RO	__pgprot(_HPAGE_TYPE_RO)
1276 #define SEGMENT_RW	__pgprot(_HPAGE_TYPE_RW)
1277 
1278 #define __HAVE_ARCH_PGTABLE_DEPOSIT
1279 extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
1280 
1281 #define __HAVE_ARCH_PGTABLE_WITHDRAW
1282 extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm);
1283 
1284 static inline int pmd_trans_splitting(pmd_t pmd)
1285 {
1286 	return pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT;
1287 }
1288 
1289 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
1290 			      pmd_t *pmdp, pmd_t entry)
1291 {
1292 	if (!(pmd_val(entry) & _SEGMENT_ENTRY_INV) && MACHINE_HAS_EDAT1)
1293 		pmd_val(entry) |= _SEGMENT_ENTRY_CO;
1294 	*pmdp = entry;
1295 }
1296 
1297 static inline unsigned long massage_pgprot_pmd(pgprot_t pgprot)
1298 {
1299 	/*
1300 	 * pgprot is PAGE_NONE, PAGE_RO, or PAGE_RW (see __Pxxx / __Sxxx)
1301 	 * Convert to segment table entry format.
1302 	 */
1303 	if (pgprot_val(pgprot) == pgprot_val(PAGE_NONE))
1304 		return pgprot_val(SEGMENT_NONE);
1305 	if (pgprot_val(pgprot) == pgprot_val(PAGE_RO))
1306 		return pgprot_val(SEGMENT_RO);
1307 	return pgprot_val(SEGMENT_RW);
1308 }
1309 
1310 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
1311 {
1312 	pmd_val(pmd) &= _SEGMENT_CHG_MASK;
1313 	pmd_val(pmd) |= massage_pgprot_pmd(newprot);
1314 	return pmd;
1315 }
1316 
1317 static inline pmd_t pmd_mkhuge(pmd_t pmd)
1318 {
1319 	pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
1320 	return pmd;
1321 }
1322 
1323 static inline pmd_t pmd_mkwrite(pmd_t pmd)
1324 {
1325 	/* Do not clobber _HPAGE_TYPE_NONE pages! */
1326 	if (!(pmd_val(pmd) & _SEGMENT_ENTRY_INV))
1327 		pmd_val(pmd) &= ~_SEGMENT_ENTRY_RO;
1328 	return pmd;
1329 }
1330 
1331 static inline pmd_t pmd_wrprotect(pmd_t pmd)
1332 {
1333 	pmd_val(pmd) |= _SEGMENT_ENTRY_RO;
1334 	return pmd;
1335 }
1336 
1337 static inline pmd_t pmd_mkdirty(pmd_t pmd)
1338 {
1339 	/* No dirty bit in the segment table entry. */
1340 	return pmd;
1341 }
1342 
1343 static inline pmd_t pmd_mkold(pmd_t pmd)
1344 {
1345 	/* No referenced bit in the segment table entry. */
1346 	return pmd;
1347 }
1348 
1349 static inline pmd_t pmd_mkyoung(pmd_t pmd)
1350 {
1351 	/* No referenced bit in the segment table entry. */
1352 	return pmd;
1353 }
1354 
1355 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1356 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
1357 					    unsigned long address, pmd_t *pmdp)
1358 {
1359 	unsigned long pmd_addr = pmd_val(*pmdp) & HPAGE_MASK;
1360 	long tmp, rc;
1361 	int counter;
1362 
1363 	rc = 0;
1364 	if (MACHINE_HAS_RRBM) {
1365 		counter = PTRS_PER_PTE >> 6;
1366 		asm volatile(
1367 			"0:	.insn	rre,0xb9ae0000,%0,%3\n"	/* rrbm */
1368 			"	ogr	%1,%0\n"
1369 			"	la	%3,0(%4,%3)\n"
1370 			"	brct	%2,0b\n"
1371 			: "=&d" (tmp), "+&d" (rc), "+d" (counter),
1372 			  "+a" (pmd_addr)
1373 			: "a" (64 * 4096UL) : "cc");
1374 		rc = !!rc;
1375 	} else {
1376 		counter = PTRS_PER_PTE;
1377 		asm volatile(
1378 			"0:	rrbe	0,%2\n"
1379 			"	la	%2,0(%3,%2)\n"
1380 			"	brc	12,1f\n"
1381 			"	lhi	%0,1\n"
1382 			"1:	brct	%1,0b\n"
1383 			: "+d" (rc), "+d" (counter), "+a" (pmd_addr)
1384 			: "a" (4096UL) : "cc");
1385 	}
1386 	return rc;
1387 }
1388 
1389 #define __HAVE_ARCH_PMDP_GET_AND_CLEAR
1390 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
1391 				       unsigned long address, pmd_t *pmdp)
1392 {
1393 	pmd_t pmd = *pmdp;
1394 
1395 	__pmd_idte(address, pmdp);
1396 	pmd_clear(pmdp);
1397 	return pmd;
1398 }
1399 
1400 #define __HAVE_ARCH_PMDP_CLEAR_FLUSH
1401 static inline pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
1402 				     unsigned long address, pmd_t *pmdp)
1403 {
1404 	return pmdp_get_and_clear(vma->vm_mm, address, pmdp);
1405 }
1406 
1407 #define __HAVE_ARCH_PMDP_INVALIDATE
1408 static inline void pmdp_invalidate(struct vm_area_struct *vma,
1409 				   unsigned long address, pmd_t *pmdp)
1410 {
1411 	__pmd_idte(address, pmdp);
1412 }
1413 
1414 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1415 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1416 				      unsigned long address, pmd_t *pmdp)
1417 {
1418 	pmd_t pmd = *pmdp;
1419 
1420 	if (pmd_write(pmd)) {
1421 		__pmd_idte(address, pmdp);
1422 		set_pmd_at(mm, address, pmdp, pmd_wrprotect(pmd));
1423 	}
1424 }
1425 
1426 static inline pmd_t mk_pmd_phys(unsigned long physpage, pgprot_t pgprot)
1427 {
1428 	pmd_t __pmd;
1429 	pmd_val(__pmd) = physpage + massage_pgprot_pmd(pgprot);
1430 	return __pmd;
1431 }
1432 
1433 #define pfn_pmd(pfn, pgprot)	mk_pmd_phys(__pa((pfn) << PAGE_SHIFT), (pgprot))
1434 #define mk_pmd(page, pgprot)	pfn_pmd(page_to_pfn(page), (pgprot))
1435 
1436 static inline int pmd_trans_huge(pmd_t pmd)
1437 {
1438 	return pmd_val(pmd) & _SEGMENT_ENTRY_LARGE;
1439 }
1440 
1441 static inline int has_transparent_hugepage(void)
1442 {
1443 	return MACHINE_HAS_HPAGE ? 1 : 0;
1444 }
1445 
1446 static inline unsigned long pmd_pfn(pmd_t pmd)
1447 {
1448 	return pmd_val(pmd) >> PAGE_SHIFT;
1449 }
1450 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1451 
1452 /*
1453  * 31 bit swap entry format:
1454  * A page-table entry has some bits we have to treat in a special way.
1455  * Bits 0, 20 and bit 23 have to be zero, otherwise an specification
1456  * exception will occur instead of a page translation exception. The
1457  * specifiation exception has the bad habit not to store necessary
1458  * information in the lowcore.
1459  * Bit 21 and bit 22 are the page invalid bit and the page protection
1460  * bit. We set both to indicate a swapped page.
1461  * Bit 30 and 31 are used to distinguish the different page types. For
1462  * a swapped page these bits need to be zero.
1463  * This leaves the bits 1-19 and bits 24-29 to store type and offset.
1464  * We use the 5 bits from 25-29 for the type and the 20 bits from 1-19
1465  * plus 24 for the offset.
1466  * 0|     offset        |0110|o|type |00|
1467  * 0 0000000001111111111 2222 2 22222 33
1468  * 0 1234567890123456789 0123 4 56789 01
1469  *
1470  * 64 bit swap entry format:
1471  * A page-table entry has some bits we have to treat in a special way.
1472  * Bits 52 and bit 55 have to be zero, otherwise an specification
1473  * exception will occur instead of a page translation exception. The
1474  * specifiation exception has the bad habit not to store necessary
1475  * information in the lowcore.
1476  * Bit 53 and bit 54 are the page invalid bit and the page protection
1477  * bit. We set both to indicate a swapped page.
1478  * Bit 62 and 63 are used to distinguish the different page types. For
1479  * a swapped page these bits need to be zero.
1480  * This leaves the bits 0-51 and bits 56-61 to store type and offset.
1481  * We use the 5 bits from 57-61 for the type and the 53 bits from 0-51
1482  * plus 56 for the offset.
1483  * |                      offset                        |0110|o|type |00|
1484  *  0000000000111111111122222222223333333333444444444455 5555 5 55566 66
1485  *  0123456789012345678901234567890123456789012345678901 2345 6 78901 23
1486  */
1487 #ifndef CONFIG_64BIT
1488 #define __SWP_OFFSET_MASK (~0UL >> 12)
1489 #else
1490 #define __SWP_OFFSET_MASK (~0UL >> 11)
1491 #endif
1492 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
1493 {
1494 	pte_t pte;
1495 	offset &= __SWP_OFFSET_MASK;
1496 	pte_val(pte) = _PAGE_TYPE_SWAP | ((type & 0x1f) << 2) |
1497 		((offset & 1UL) << 7) | ((offset & ~1UL) << 11);
1498 	return pte;
1499 }
1500 
1501 #define __swp_type(entry)	(((entry).val >> 2) & 0x1f)
1502 #define __swp_offset(entry)	(((entry).val >> 11) | (((entry).val >> 7) & 1))
1503 #define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) })
1504 
1505 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1506 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
1507 
1508 #ifndef CONFIG_64BIT
1509 # define PTE_FILE_MAX_BITS	26
1510 #else /* CONFIG_64BIT */
1511 # define PTE_FILE_MAX_BITS	59
1512 #endif /* CONFIG_64BIT */
1513 
1514 #define pte_to_pgoff(__pte) \
1515 	((((__pte).pte >> 12) << 7) + (((__pte).pte >> 1) & 0x7f))
1516 
1517 #define pgoff_to_pte(__off) \
1518 	((pte_t) { ((((__off) & 0x7f) << 1) + (((__off) >> 7) << 12)) \
1519 		   | _PAGE_TYPE_FILE })
1520 
1521 #endif /* !__ASSEMBLY__ */
1522 
1523 #define kern_addr_valid(addr)   (1)
1524 
1525 extern int vmem_add_mapping(unsigned long start, unsigned long size);
1526 extern int vmem_remove_mapping(unsigned long start, unsigned long size);
1527 extern int s390_enable_sie(void);
1528 
1529 /*
1530  * No page table caches to initialise
1531  */
1532 #define pgtable_cache_init()	do { } while (0)
1533 
1534 #include <asm-generic/pgtable.h>
1535 
1536 #endif /* _S390_PAGE_H */
1537