xref: /openbmc/linux/arch/s390/include/asm/pgtable.h (revision 8dd99871)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  S390 version
4  *    Copyright IBM Corp. 1999, 2000
5  *    Author(s): Hartmut Penner (hp@de.ibm.com)
6  *               Ulrich Weigand (weigand@de.ibm.com)
7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
8  *
9  *  Derived from "include/asm-i386/pgtable.h"
10  */
11 
12 #ifndef _ASM_S390_PGTABLE_H
13 #define _ASM_S390_PGTABLE_H
14 
15 #include <linux/sched.h>
16 #include <linux/mm_types.h>
17 #include <linux/page-flags.h>
18 #include <linux/radix-tree.h>
19 #include <linux/atomic.h>
20 #include <asm/bug.h>
21 #include <asm/page.h>
22 
23 extern pgd_t swapper_pg_dir[];
24 extern void paging_init(void);
25 
26 enum {
27 	PG_DIRECT_MAP_4K = 0,
28 	PG_DIRECT_MAP_1M,
29 	PG_DIRECT_MAP_2G,
30 	PG_DIRECT_MAP_MAX
31 };
32 
33 extern atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];
34 
35 static inline void update_page_count(int level, long count)
36 {
37 	if (IS_ENABLED(CONFIG_PROC_FS))
38 		atomic_long_add(count, &direct_pages_count[level]);
39 }
40 
41 struct seq_file;
42 void arch_report_meminfo(struct seq_file *m);
43 
44 /*
45  * The S390 doesn't have any external MMU info: the kernel page
46  * tables contain all the necessary information.
47  */
48 #define update_mmu_cache(vma, address, ptep)     do { } while (0)
49 #define update_mmu_cache_pmd(vma, address, ptep) do { } while (0)
50 
51 /*
52  * ZERO_PAGE is a global shared page that is always zero; used
53  * for zero-mapped memory areas etc..
54  */
55 
56 extern unsigned long empty_zero_page;
57 extern unsigned long zero_page_mask;
58 
59 #define ZERO_PAGE(vaddr) \
60 	(virt_to_page((void *)(empty_zero_page + \
61 	 (((unsigned long)(vaddr)) &zero_page_mask))))
62 #define __HAVE_COLOR_ZERO_PAGE
63 
64 /* TODO: s390 cannot support io_remap_pfn_range... */
65 
66 #define FIRST_USER_ADDRESS  0UL
67 
68 #define pte_ERROR(e) \
69 	printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e))
70 #define pmd_ERROR(e) \
71 	printk("%s:%d: bad pmd %p.\n", __FILE__, __LINE__, (void *) pmd_val(e))
72 #define pud_ERROR(e) \
73 	printk("%s:%d: bad pud %p.\n", __FILE__, __LINE__, (void *) pud_val(e))
74 #define p4d_ERROR(e) \
75 	printk("%s:%d: bad p4d %p.\n", __FILE__, __LINE__, (void *) p4d_val(e))
76 #define pgd_ERROR(e) \
77 	printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) pgd_val(e))
78 
79 /*
80  * The vmalloc and module area will always be on the topmost area of the
81  * kernel mapping. We reserve 128GB (64bit) for vmalloc and modules.
82  * On 64 bit kernels we have a 2GB area at the top of the vmalloc area where
83  * modules will reside. That makes sure that inter module branches always
84  * happen without trampolines and in addition the placement within a 2GB frame
85  * is branch prediction unit friendly.
86  */
87 extern unsigned long VMALLOC_START;
88 extern unsigned long VMALLOC_END;
89 extern struct page *vmemmap;
90 
91 #define VMEM_MAX_PHYS ((unsigned long) vmemmap)
92 
93 extern unsigned long MODULES_VADDR;
94 extern unsigned long MODULES_END;
95 #define MODULES_VADDR	MODULES_VADDR
96 #define MODULES_END	MODULES_END
97 #define MODULES_LEN	(1UL << 31)
98 
99 static inline int is_module_addr(void *addr)
100 {
101 	BUILD_BUG_ON(MODULES_LEN > (1UL << 31));
102 	if (addr < (void *)MODULES_VADDR)
103 		return 0;
104 	if (addr > (void *)MODULES_END)
105 		return 0;
106 	return 1;
107 }
108 
109 /*
110  * A 64 bit pagetable entry of S390 has following format:
111  * |			 PFRA			      |0IPC|  OS  |
112  * 0000000000111111111122222222223333333333444444444455555555556666
113  * 0123456789012345678901234567890123456789012345678901234567890123
114  *
115  * I Page-Invalid Bit:    Page is not available for address-translation
116  * P Page-Protection Bit: Store access not possible for page
117  * C Change-bit override: HW is not required to set change bit
118  *
119  * A 64 bit segmenttable entry of S390 has following format:
120  * |        P-table origin                              |      TT
121  * 0000000000111111111122222222223333333333444444444455555555556666
122  * 0123456789012345678901234567890123456789012345678901234567890123
123  *
124  * I Segment-Invalid Bit:    Segment is not available for address-translation
125  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
126  * P Page-Protection Bit: Store access not possible for page
127  * TT Type 00
128  *
129  * A 64 bit region table entry of S390 has following format:
130  * |        S-table origin                             |   TF  TTTL
131  * 0000000000111111111122222222223333333333444444444455555555556666
132  * 0123456789012345678901234567890123456789012345678901234567890123
133  *
134  * I Segment-Invalid Bit:    Segment is not available for address-translation
135  * TT Type 01
136  * TF
137  * TL Table length
138  *
139  * The 64 bit regiontable origin of S390 has following format:
140  * |      region table origon                          |       DTTL
141  * 0000000000111111111122222222223333333333444444444455555555556666
142  * 0123456789012345678901234567890123456789012345678901234567890123
143  *
144  * X Space-Switch event:
145  * G Segment-Invalid Bit:
146  * P Private-Space Bit:
147  * S Storage-Alteration:
148  * R Real space
149  * TL Table-Length:
150  *
151  * A storage key has the following format:
152  * | ACC |F|R|C|0|
153  *  0   3 4 5 6 7
154  * ACC: access key
155  * F  : fetch protection bit
156  * R  : referenced bit
157  * C  : changed bit
158  */
159 
160 /* Hardware bits in the page table entry */
161 #define _PAGE_NOEXEC	0x100		/* HW no-execute bit  */
162 #define _PAGE_PROTECT	0x200		/* HW read-only bit  */
163 #define _PAGE_INVALID	0x400		/* HW invalid bit    */
164 #define _PAGE_LARGE	0x800		/* Bit to mark a large pte */
165 
166 /* Software bits in the page table entry */
167 #define _PAGE_PRESENT	0x001		/* SW pte present bit */
168 #define _PAGE_YOUNG	0x004		/* SW pte young bit */
169 #define _PAGE_DIRTY	0x008		/* SW pte dirty bit */
170 #define _PAGE_READ	0x010		/* SW pte read bit */
171 #define _PAGE_WRITE	0x020		/* SW pte write bit */
172 #define _PAGE_SPECIAL	0x040		/* SW associated with special page */
173 #define _PAGE_UNUSED	0x080		/* SW bit for pgste usage state */
174 
175 #ifdef CONFIG_MEM_SOFT_DIRTY
176 #define _PAGE_SOFT_DIRTY 0x002		/* SW pte soft dirty bit */
177 #else
178 #define _PAGE_SOFT_DIRTY 0x000
179 #endif
180 
181 /* Set of bits not changed in pte_modify */
182 #define _PAGE_CHG_MASK		(PAGE_MASK | _PAGE_SPECIAL | _PAGE_DIRTY | \
183 				 _PAGE_YOUNG | _PAGE_SOFT_DIRTY)
184 
185 /*
186  * handle_pte_fault uses pte_present and pte_none to find out the pte type
187  * WITHOUT holding the page table lock. The _PAGE_PRESENT bit is used to
188  * distinguish present from not-present ptes. It is changed only with the page
189  * table lock held.
190  *
191  * The following table gives the different possible bit combinations for
192  * the pte hardware and software bits in the last 12 bits of a pte
193  * (. unassigned bit, x don't care, t swap type):
194  *
195  *				842100000000
196  *				000084210000
197  *				000000008421
198  *				.IR.uswrdy.p
199  * empty			.10.00000000
200  * swap				.11..ttttt.0
201  * prot-none, clean, old	.11.xx0000.1
202  * prot-none, clean, young	.11.xx0001.1
203  * prot-none, dirty, old	.11.xx0010.1
204  * prot-none, dirty, young	.11.xx0011.1
205  * read-only, clean, old	.11.xx0100.1
206  * read-only, clean, young	.01.xx0101.1
207  * read-only, dirty, old	.11.xx0110.1
208  * read-only, dirty, young	.01.xx0111.1
209  * read-write, clean, old	.11.xx1100.1
210  * read-write, clean, young	.01.xx1101.1
211  * read-write, dirty, old	.10.xx1110.1
212  * read-write, dirty, young	.00.xx1111.1
213  * HW-bits: R read-only, I invalid
214  * SW-bits: p present, y young, d dirty, r read, w write, s special,
215  *	    u unused, l large
216  *
217  * pte_none    is true for the bit pattern .10.00000000, pte == 0x400
218  * pte_swap    is true for the bit pattern .11..ooooo.0, (pte & 0x201) == 0x200
219  * pte_present is true for the bit pattern .xx.xxxxxx.1, (pte & 0x001) == 0x001
220  */
221 
222 /* Bits in the segment/region table address-space-control-element */
223 #define _ASCE_ORIGIN		~0xfffUL/* region/segment table origin	    */
224 #define _ASCE_PRIVATE_SPACE	0x100	/* private space control	    */
225 #define _ASCE_ALT_EVENT		0x80	/* storage alteration event control */
226 #define _ASCE_SPACE_SWITCH	0x40	/* space switch event		    */
227 #define _ASCE_REAL_SPACE	0x20	/* real space control		    */
228 #define _ASCE_TYPE_MASK		0x0c	/* asce table type mask		    */
229 #define _ASCE_TYPE_REGION1	0x0c	/* region first table type	    */
230 #define _ASCE_TYPE_REGION2	0x08	/* region second table type	    */
231 #define _ASCE_TYPE_REGION3	0x04	/* region third table type	    */
232 #define _ASCE_TYPE_SEGMENT	0x00	/* segment table type		    */
233 #define _ASCE_TABLE_LENGTH	0x03	/* region table length		    */
234 
235 /* Bits in the region table entry */
236 #define _REGION_ENTRY_ORIGIN	~0xfffUL/* region/segment table origin	    */
237 #define _REGION_ENTRY_PROTECT	0x200	/* region protection bit	    */
238 #define _REGION_ENTRY_NOEXEC	0x100	/* region no-execute bit	    */
239 #define _REGION_ENTRY_OFFSET	0xc0	/* region table offset		    */
240 #define _REGION_ENTRY_INVALID	0x20	/* invalid region table entry	    */
241 #define _REGION_ENTRY_TYPE_MASK	0x0c	/* region/segment table type mask   */
242 #define _REGION_ENTRY_TYPE_R1	0x0c	/* region first table type	    */
243 #define _REGION_ENTRY_TYPE_R2	0x08	/* region second table type	    */
244 #define _REGION_ENTRY_TYPE_R3	0x04	/* region third table type	    */
245 #define _REGION_ENTRY_LENGTH	0x03	/* region third length		    */
246 
247 #define _REGION1_ENTRY		(_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_LENGTH)
248 #define _REGION1_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID)
249 #define _REGION2_ENTRY		(_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_LENGTH)
250 #define _REGION2_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID)
251 #define _REGION3_ENTRY		(_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_LENGTH)
252 #define _REGION3_ENTRY_EMPTY	(_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID)
253 
254 #define _REGION3_ENTRY_ORIGIN_LARGE ~0x7fffffffUL /* large page address	     */
255 #define _REGION3_ENTRY_DIRTY	0x2000	/* SW region dirty bit */
256 #define _REGION3_ENTRY_YOUNG	0x1000	/* SW region young bit */
257 #define _REGION3_ENTRY_LARGE	0x0400	/* RTTE-format control, large page  */
258 #define _REGION3_ENTRY_READ	0x0002	/* SW region read bit */
259 #define _REGION3_ENTRY_WRITE	0x0001	/* SW region write bit */
260 
261 #ifdef CONFIG_MEM_SOFT_DIRTY
262 #define _REGION3_ENTRY_SOFT_DIRTY 0x4000 /* SW region soft dirty bit */
263 #else
264 #define _REGION3_ENTRY_SOFT_DIRTY 0x0000 /* SW region soft dirty bit */
265 #endif
266 
267 #define _REGION_ENTRY_BITS	 0xfffffffffffff22fUL
268 #define _REGION_ENTRY_BITS_LARGE 0xffffffff8000fe2fUL
269 
270 /* Bits in the segment table entry */
271 #define _SEGMENT_ENTRY_BITS	0xfffffffffffffe33UL
272 #define _SEGMENT_ENTRY_BITS_LARGE 0xfffffffffff0ff33UL
273 #define _SEGMENT_ENTRY_ORIGIN_LARGE ~0xfffffUL /* large page address	    */
274 #define _SEGMENT_ENTRY_ORIGIN	~0x7ffUL/* page table origin		    */
275 #define _SEGMENT_ENTRY_PROTECT	0x200	/* segment protection bit	    */
276 #define _SEGMENT_ENTRY_NOEXEC	0x100	/* segment no-execute bit	    */
277 #define _SEGMENT_ENTRY_INVALID	0x20	/* invalid segment table entry	    */
278 
279 #define _SEGMENT_ENTRY		(0)
280 #define _SEGMENT_ENTRY_EMPTY	(_SEGMENT_ENTRY_INVALID)
281 
282 #define _SEGMENT_ENTRY_DIRTY	0x2000	/* SW segment dirty bit */
283 #define _SEGMENT_ENTRY_YOUNG	0x1000	/* SW segment young bit */
284 #define _SEGMENT_ENTRY_LARGE	0x0400	/* STE-format control, large page */
285 #define _SEGMENT_ENTRY_WRITE	0x0002	/* SW segment write bit */
286 #define _SEGMENT_ENTRY_READ	0x0001	/* SW segment read bit */
287 
288 #ifdef CONFIG_MEM_SOFT_DIRTY
289 #define _SEGMENT_ENTRY_SOFT_DIRTY 0x4000 /* SW segment soft dirty bit */
290 #else
291 #define _SEGMENT_ENTRY_SOFT_DIRTY 0x0000 /* SW segment soft dirty bit */
292 #endif
293 
294 #define _CRST_ENTRIES	2048	/* number of region/segment table entries */
295 #define _PAGE_ENTRIES	256	/* number of page table entries	*/
296 
297 #define _CRST_TABLE_SIZE (_CRST_ENTRIES * 8)
298 #define _PAGE_TABLE_SIZE (_PAGE_ENTRIES * 8)
299 
300 #define _REGION1_SHIFT	53
301 #define _REGION2_SHIFT	42
302 #define _REGION3_SHIFT	31
303 #define _SEGMENT_SHIFT	20
304 
305 #define _REGION1_INDEX	(0x7ffUL << _REGION1_SHIFT)
306 #define _REGION2_INDEX	(0x7ffUL << _REGION2_SHIFT)
307 #define _REGION3_INDEX	(0x7ffUL << _REGION3_SHIFT)
308 #define _SEGMENT_INDEX	(0x7ffUL << _SEGMENT_SHIFT)
309 #define _PAGE_INDEX	(0xffUL  << _PAGE_SHIFT)
310 
311 #define _REGION1_SIZE	(1UL << _REGION1_SHIFT)
312 #define _REGION2_SIZE	(1UL << _REGION2_SHIFT)
313 #define _REGION3_SIZE	(1UL << _REGION3_SHIFT)
314 #define _SEGMENT_SIZE	(1UL << _SEGMENT_SHIFT)
315 
316 #define _REGION1_MASK	(~(_REGION1_SIZE - 1))
317 #define _REGION2_MASK	(~(_REGION2_SIZE - 1))
318 #define _REGION3_MASK	(~(_REGION3_SIZE - 1))
319 #define _SEGMENT_MASK	(~(_SEGMENT_SIZE - 1))
320 
321 #define PMD_SHIFT	_SEGMENT_SHIFT
322 #define PUD_SHIFT	_REGION3_SHIFT
323 #define P4D_SHIFT	_REGION2_SHIFT
324 #define PGDIR_SHIFT	_REGION1_SHIFT
325 
326 #define PMD_SIZE	_SEGMENT_SIZE
327 #define PUD_SIZE	_REGION3_SIZE
328 #define P4D_SIZE	_REGION2_SIZE
329 #define PGDIR_SIZE	_REGION1_SIZE
330 
331 #define PMD_MASK	_SEGMENT_MASK
332 #define PUD_MASK	_REGION3_MASK
333 #define P4D_MASK	_REGION2_MASK
334 #define PGDIR_MASK	_REGION1_MASK
335 
336 #define PTRS_PER_PTE	_PAGE_ENTRIES
337 #define PTRS_PER_PMD	_CRST_ENTRIES
338 #define PTRS_PER_PUD	_CRST_ENTRIES
339 #define PTRS_PER_P4D	_CRST_ENTRIES
340 #define PTRS_PER_PGD	_CRST_ENTRIES
341 
342 /*
343  * Segment table and region3 table entry encoding
344  * (R = read-only, I = invalid, y = young bit):
345  *				dy..R...I...wr
346  * prot-none, clean, old	00..1...1...00
347  * prot-none, clean, young	01..1...1...00
348  * prot-none, dirty, old	10..1...1...00
349  * prot-none, dirty, young	11..1...1...00
350  * read-only, clean, old	00..1...1...01
351  * read-only, clean, young	01..1...0...01
352  * read-only, dirty, old	10..1...1...01
353  * read-only, dirty, young	11..1...0...01
354  * read-write, clean, old	00..1...1...11
355  * read-write, clean, young	01..1...0...11
356  * read-write, dirty, old	10..0...1...11
357  * read-write, dirty, young	11..0...0...11
358  * The segment table origin is used to distinguish empty (origin==0) from
359  * read-write, old segment table entries (origin!=0)
360  * HW-bits: R read-only, I invalid
361  * SW-bits: y young, d dirty, r read, w write
362  */
363 
364 /* Page status table bits for virtualization */
365 #define PGSTE_ACC_BITS	0xf000000000000000UL
366 #define PGSTE_FP_BIT	0x0800000000000000UL
367 #define PGSTE_PCL_BIT	0x0080000000000000UL
368 #define PGSTE_HR_BIT	0x0040000000000000UL
369 #define PGSTE_HC_BIT	0x0020000000000000UL
370 #define PGSTE_GR_BIT	0x0004000000000000UL
371 #define PGSTE_GC_BIT	0x0002000000000000UL
372 #define PGSTE_UC_BIT	0x0000800000000000UL	/* user dirty (migration) */
373 #define PGSTE_IN_BIT	0x0000400000000000UL	/* IPTE notify bit */
374 #define PGSTE_VSIE_BIT	0x0000200000000000UL	/* ref'd in a shadow table */
375 
376 /* Guest Page State used for virtualization */
377 #define _PGSTE_GPS_ZERO			0x0000000080000000UL
378 #define _PGSTE_GPS_NODAT		0x0000000040000000UL
379 #define _PGSTE_GPS_USAGE_MASK		0x0000000003000000UL
380 #define _PGSTE_GPS_USAGE_STABLE		0x0000000000000000UL
381 #define _PGSTE_GPS_USAGE_UNUSED		0x0000000001000000UL
382 #define _PGSTE_GPS_USAGE_POT_VOLATILE	0x0000000002000000UL
383 #define _PGSTE_GPS_USAGE_VOLATILE	_PGSTE_GPS_USAGE_MASK
384 
385 /*
386  * A user page table pointer has the space-switch-event bit, the
387  * private-space-control bit and the storage-alteration-event-control
388  * bit set. A kernel page table pointer doesn't need them.
389  */
390 #define _ASCE_USER_BITS		(_ASCE_SPACE_SWITCH | _ASCE_PRIVATE_SPACE | \
391 				 _ASCE_ALT_EVENT)
392 
393 /*
394  * Page protection definitions.
395  */
396 #define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_INVALID | _PAGE_PROTECT)
397 #define PAGE_RO		__pgprot(_PAGE_PRESENT | _PAGE_READ | \
398 				 _PAGE_NOEXEC  | _PAGE_INVALID | _PAGE_PROTECT)
399 #define PAGE_RX		__pgprot(_PAGE_PRESENT | _PAGE_READ | \
400 				 _PAGE_INVALID | _PAGE_PROTECT)
401 #define PAGE_RW		__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
402 				 _PAGE_NOEXEC  | _PAGE_INVALID | _PAGE_PROTECT)
403 #define PAGE_RWX	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
404 				 _PAGE_INVALID | _PAGE_PROTECT)
405 
406 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
407 				 _PAGE_YOUNG | _PAGE_DIRTY | _PAGE_NOEXEC)
408 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
409 				 _PAGE_YOUNG | _PAGE_DIRTY | _PAGE_NOEXEC)
410 #define PAGE_KERNEL_RO	__pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_YOUNG | \
411 				 _PAGE_PROTECT | _PAGE_NOEXEC)
412 #define PAGE_KERNEL_EXEC __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
413 				  _PAGE_YOUNG |	_PAGE_DIRTY)
414 
415 /*
416  * On s390 the page table entry has an invalid bit and a read-only bit.
417  * Read permission implies execute permission and write permission
418  * implies read permission.
419  */
420          /*xwr*/
421 #define __P000	PAGE_NONE
422 #define __P001	PAGE_RO
423 #define __P010	PAGE_RO
424 #define __P011	PAGE_RO
425 #define __P100	PAGE_RX
426 #define __P101	PAGE_RX
427 #define __P110	PAGE_RX
428 #define __P111	PAGE_RX
429 
430 #define __S000	PAGE_NONE
431 #define __S001	PAGE_RO
432 #define __S010	PAGE_RW
433 #define __S011	PAGE_RW
434 #define __S100	PAGE_RX
435 #define __S101	PAGE_RX
436 #define __S110	PAGE_RWX
437 #define __S111	PAGE_RWX
438 
439 /*
440  * Segment entry (large page) protection definitions.
441  */
442 #define SEGMENT_NONE	__pgprot(_SEGMENT_ENTRY_INVALID | \
443 				 _SEGMENT_ENTRY_PROTECT)
444 #define SEGMENT_RO	__pgprot(_SEGMENT_ENTRY_PROTECT | \
445 				 _SEGMENT_ENTRY_READ | \
446 				 _SEGMENT_ENTRY_NOEXEC)
447 #define SEGMENT_RX	__pgprot(_SEGMENT_ENTRY_PROTECT | \
448 				 _SEGMENT_ENTRY_READ)
449 #define SEGMENT_RW	__pgprot(_SEGMENT_ENTRY_READ | \
450 				 _SEGMENT_ENTRY_WRITE | \
451 				 _SEGMENT_ENTRY_NOEXEC)
452 #define SEGMENT_RWX	__pgprot(_SEGMENT_ENTRY_READ | \
453 				 _SEGMENT_ENTRY_WRITE)
454 #define SEGMENT_KERNEL	__pgprot(_SEGMENT_ENTRY |	\
455 				 _SEGMENT_ENTRY_LARGE |	\
456 				 _SEGMENT_ENTRY_READ |	\
457 				 _SEGMENT_ENTRY_WRITE | \
458 				 _SEGMENT_ENTRY_YOUNG | \
459 				 _SEGMENT_ENTRY_DIRTY | \
460 				 _SEGMENT_ENTRY_NOEXEC)
461 #define SEGMENT_KERNEL_RO __pgprot(_SEGMENT_ENTRY |	\
462 				 _SEGMENT_ENTRY_LARGE |	\
463 				 _SEGMENT_ENTRY_READ |	\
464 				 _SEGMENT_ENTRY_YOUNG |	\
465 				 _SEGMENT_ENTRY_PROTECT | \
466 				 _SEGMENT_ENTRY_NOEXEC)
467 
468 /*
469  * Region3 entry (large page) protection definitions.
470  */
471 
472 #define REGION3_KERNEL	__pgprot(_REGION_ENTRY_TYPE_R3 | \
473 				 _REGION3_ENTRY_LARGE |	 \
474 				 _REGION3_ENTRY_READ |	 \
475 				 _REGION3_ENTRY_WRITE |	 \
476 				 _REGION3_ENTRY_YOUNG |	 \
477 				 _REGION3_ENTRY_DIRTY | \
478 				 _REGION_ENTRY_NOEXEC)
479 #define REGION3_KERNEL_RO __pgprot(_REGION_ENTRY_TYPE_R3 | \
480 				   _REGION3_ENTRY_LARGE |  \
481 				   _REGION3_ENTRY_READ |   \
482 				   _REGION3_ENTRY_YOUNG |  \
483 				   _REGION_ENTRY_PROTECT | \
484 				   _REGION_ENTRY_NOEXEC)
485 
486 static inline int mm_has_pgste(struct mm_struct *mm)
487 {
488 #ifdef CONFIG_PGSTE
489 	if (unlikely(mm->context.has_pgste))
490 		return 1;
491 #endif
492 	return 0;
493 }
494 
495 static inline int mm_alloc_pgste(struct mm_struct *mm)
496 {
497 #ifdef CONFIG_PGSTE
498 	if (unlikely(mm->context.alloc_pgste))
499 		return 1;
500 #endif
501 	return 0;
502 }
503 
504 /*
505  * In the case that a guest uses storage keys
506  * faults should no longer be backed by zero pages
507  */
508 #define mm_forbids_zeropage mm_has_pgste
509 static inline int mm_uses_skeys(struct mm_struct *mm)
510 {
511 #ifdef CONFIG_PGSTE
512 	if (mm->context.uses_skeys)
513 		return 1;
514 #endif
515 	return 0;
516 }
517 
518 static inline void csp(unsigned int *ptr, unsigned int old, unsigned int new)
519 {
520 	register unsigned long reg2 asm("2") = old;
521 	register unsigned long reg3 asm("3") = new;
522 	unsigned long address = (unsigned long)ptr | 1;
523 
524 	asm volatile(
525 		"	csp	%0,%3"
526 		: "+d" (reg2), "+m" (*ptr)
527 		: "d" (reg3), "d" (address)
528 		: "cc");
529 }
530 
531 static inline void cspg(unsigned long *ptr, unsigned long old, unsigned long new)
532 {
533 	register unsigned long reg2 asm("2") = old;
534 	register unsigned long reg3 asm("3") = new;
535 	unsigned long address = (unsigned long)ptr | 1;
536 
537 	asm volatile(
538 		"	.insn	rre,0xb98a0000,%0,%3"
539 		: "+d" (reg2), "+m" (*ptr)
540 		: "d" (reg3), "d" (address)
541 		: "cc");
542 }
543 
544 #define CRDTE_DTT_PAGE		0x00UL
545 #define CRDTE_DTT_SEGMENT	0x10UL
546 #define CRDTE_DTT_REGION3	0x14UL
547 #define CRDTE_DTT_REGION2	0x18UL
548 #define CRDTE_DTT_REGION1	0x1cUL
549 
550 static inline void crdte(unsigned long old, unsigned long new,
551 			 unsigned long table, unsigned long dtt,
552 			 unsigned long address, unsigned long asce)
553 {
554 	register unsigned long reg2 asm("2") = old;
555 	register unsigned long reg3 asm("3") = new;
556 	register unsigned long reg4 asm("4") = table | dtt;
557 	register unsigned long reg5 asm("5") = address;
558 
559 	asm volatile(".insn rrf,0xb98f0000,%0,%2,%4,0"
560 		     : "+d" (reg2)
561 		     : "d" (reg3), "d" (reg4), "d" (reg5), "a" (asce)
562 		     : "memory", "cc");
563 }
564 
565 /*
566  * pgd/p4d/pud/pmd/pte query functions
567  */
568 static inline int pgd_folded(pgd_t pgd)
569 {
570 	return (pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R1;
571 }
572 
573 static inline int pgd_present(pgd_t pgd)
574 {
575 	if (pgd_folded(pgd))
576 		return 1;
577 	return (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) != 0UL;
578 }
579 
580 static inline int pgd_none(pgd_t pgd)
581 {
582 	if (pgd_folded(pgd))
583 		return 0;
584 	return (pgd_val(pgd) & _REGION_ENTRY_INVALID) != 0UL;
585 }
586 
587 static inline int pgd_bad(pgd_t pgd)
588 {
589 	/*
590 	 * With dynamic page table levels the pgd can be a region table
591 	 * entry or a segment table entry. Check for the bit that are
592 	 * invalid for either table entry.
593 	 */
594 	unsigned long mask =
595 		~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INVALID &
596 		~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH;
597 	return (pgd_val(pgd) & mask) != 0;
598 }
599 
600 static inline int p4d_folded(p4d_t p4d)
601 {
602 	return (p4d_val(p4d) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2;
603 }
604 
605 static inline int p4d_present(p4d_t p4d)
606 {
607 	if (p4d_folded(p4d))
608 		return 1;
609 	return (p4d_val(p4d) & _REGION_ENTRY_ORIGIN) != 0UL;
610 }
611 
612 static inline int p4d_none(p4d_t p4d)
613 {
614 	if (p4d_folded(p4d))
615 		return 0;
616 	return p4d_val(p4d) == _REGION2_ENTRY_EMPTY;
617 }
618 
619 static inline unsigned long p4d_pfn(p4d_t p4d)
620 {
621 	unsigned long origin_mask;
622 
623 	origin_mask = _REGION_ENTRY_ORIGIN;
624 	return (p4d_val(p4d) & origin_mask) >> PAGE_SHIFT;
625 }
626 
627 static inline int pud_folded(pud_t pud)
628 {
629 	return (pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3;
630 }
631 
632 static inline int pud_present(pud_t pud)
633 {
634 	if (pud_folded(pud))
635 		return 1;
636 	return (pud_val(pud) & _REGION_ENTRY_ORIGIN) != 0UL;
637 }
638 
639 static inline int pud_none(pud_t pud)
640 {
641 	if (pud_folded(pud))
642 		return 0;
643 	return pud_val(pud) == _REGION3_ENTRY_EMPTY;
644 }
645 
646 static inline int pud_large(pud_t pud)
647 {
648 	if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) != _REGION_ENTRY_TYPE_R3)
649 		return 0;
650 	return !!(pud_val(pud) & _REGION3_ENTRY_LARGE);
651 }
652 
653 static inline unsigned long pud_pfn(pud_t pud)
654 {
655 	unsigned long origin_mask;
656 
657 	origin_mask = _REGION_ENTRY_ORIGIN;
658 	if (pud_large(pud))
659 		origin_mask = _REGION3_ENTRY_ORIGIN_LARGE;
660 	return (pud_val(pud) & origin_mask) >> PAGE_SHIFT;
661 }
662 
663 static inline int pmd_large(pmd_t pmd)
664 {
665 	return (pmd_val(pmd) & _SEGMENT_ENTRY_LARGE) != 0;
666 }
667 
668 static inline int pmd_bad(pmd_t pmd)
669 {
670 	if (pmd_large(pmd))
671 		return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS_LARGE) != 0;
672 	return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS) != 0;
673 }
674 
675 static inline int pud_bad(pud_t pud)
676 {
677 	if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3)
678 		return pmd_bad(__pmd(pud_val(pud)));
679 	if (pud_large(pud))
680 		return (pud_val(pud) & ~_REGION_ENTRY_BITS_LARGE) != 0;
681 	return (pud_val(pud) & ~_REGION_ENTRY_BITS) != 0;
682 }
683 
684 static inline int p4d_bad(p4d_t p4d)
685 {
686 	if ((p4d_val(p4d) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2)
687 		return pud_bad(__pud(p4d_val(p4d)));
688 	return (p4d_val(p4d) & ~_REGION_ENTRY_BITS) != 0;
689 }
690 
691 static inline int pmd_present(pmd_t pmd)
692 {
693 	return pmd_val(pmd) != _SEGMENT_ENTRY_EMPTY;
694 }
695 
696 static inline int pmd_none(pmd_t pmd)
697 {
698 	return pmd_val(pmd) == _SEGMENT_ENTRY_EMPTY;
699 }
700 
701 static inline unsigned long pmd_pfn(pmd_t pmd)
702 {
703 	unsigned long origin_mask;
704 
705 	origin_mask = _SEGMENT_ENTRY_ORIGIN;
706 	if (pmd_large(pmd))
707 		origin_mask = _SEGMENT_ENTRY_ORIGIN_LARGE;
708 	return (pmd_val(pmd) & origin_mask) >> PAGE_SHIFT;
709 }
710 
711 #define pmd_write pmd_write
712 static inline int pmd_write(pmd_t pmd)
713 {
714 	return (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) != 0;
715 }
716 
717 static inline int pmd_dirty(pmd_t pmd)
718 {
719 	int dirty = 1;
720 	if (pmd_large(pmd))
721 		dirty = (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) != 0;
722 	return dirty;
723 }
724 
725 static inline int pmd_young(pmd_t pmd)
726 {
727 	int young = 1;
728 	if (pmd_large(pmd))
729 		young = (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) != 0;
730 	return young;
731 }
732 
733 static inline int pte_present(pte_t pte)
734 {
735 	/* Bit pattern: (pte & 0x001) == 0x001 */
736 	return (pte_val(pte) & _PAGE_PRESENT) != 0;
737 }
738 
739 static inline int pte_none(pte_t pte)
740 {
741 	/* Bit pattern: pte == 0x400 */
742 	return pte_val(pte) == _PAGE_INVALID;
743 }
744 
745 static inline int pte_swap(pte_t pte)
746 {
747 	/* Bit pattern: (pte & 0x201) == 0x200 */
748 	return (pte_val(pte) & (_PAGE_PROTECT | _PAGE_PRESENT))
749 		== _PAGE_PROTECT;
750 }
751 
752 static inline int pte_special(pte_t pte)
753 {
754 	return (pte_val(pte) & _PAGE_SPECIAL);
755 }
756 
757 #define __HAVE_ARCH_PTE_SAME
758 static inline int pte_same(pte_t a, pte_t b)
759 {
760 	return pte_val(a) == pte_val(b);
761 }
762 
763 #ifdef CONFIG_NUMA_BALANCING
764 static inline int pte_protnone(pte_t pte)
765 {
766 	return pte_present(pte) && !(pte_val(pte) & _PAGE_READ);
767 }
768 
769 static inline int pmd_protnone(pmd_t pmd)
770 {
771 	/* pmd_large(pmd) implies pmd_present(pmd) */
772 	return pmd_large(pmd) && !(pmd_val(pmd) & _SEGMENT_ENTRY_READ);
773 }
774 #endif
775 
776 static inline int pte_soft_dirty(pte_t pte)
777 {
778 	return pte_val(pte) & _PAGE_SOFT_DIRTY;
779 }
780 #define pte_swp_soft_dirty pte_soft_dirty
781 
782 static inline pte_t pte_mksoft_dirty(pte_t pte)
783 {
784 	pte_val(pte) |= _PAGE_SOFT_DIRTY;
785 	return pte;
786 }
787 #define pte_swp_mksoft_dirty pte_mksoft_dirty
788 
789 static inline pte_t pte_clear_soft_dirty(pte_t pte)
790 {
791 	pte_val(pte) &= ~_PAGE_SOFT_DIRTY;
792 	return pte;
793 }
794 #define pte_swp_clear_soft_dirty pte_clear_soft_dirty
795 
796 static inline int pmd_soft_dirty(pmd_t pmd)
797 {
798 	return pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY;
799 }
800 
801 static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
802 {
803 	pmd_val(pmd) |= _SEGMENT_ENTRY_SOFT_DIRTY;
804 	return pmd;
805 }
806 
807 static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
808 {
809 	pmd_val(pmd) &= ~_SEGMENT_ENTRY_SOFT_DIRTY;
810 	return pmd;
811 }
812 
813 /*
814  * query functions pte_write/pte_dirty/pte_young only work if
815  * pte_present() is true. Undefined behaviour if not..
816  */
817 static inline int pte_write(pte_t pte)
818 {
819 	return (pte_val(pte) & _PAGE_WRITE) != 0;
820 }
821 
822 static inline int pte_dirty(pte_t pte)
823 {
824 	return (pte_val(pte) & _PAGE_DIRTY) != 0;
825 }
826 
827 static inline int pte_young(pte_t pte)
828 {
829 	return (pte_val(pte) & _PAGE_YOUNG) != 0;
830 }
831 
832 #define __HAVE_ARCH_PTE_UNUSED
833 static inline int pte_unused(pte_t pte)
834 {
835 	return pte_val(pte) & _PAGE_UNUSED;
836 }
837 
838 /*
839  * pgd/pmd/pte modification functions
840  */
841 
842 static inline void pgd_clear(pgd_t *pgd)
843 {
844 	if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R1)
845 		pgd_val(*pgd) = _REGION1_ENTRY_EMPTY;
846 }
847 
848 static inline void p4d_clear(p4d_t *p4d)
849 {
850 	if ((p4d_val(*p4d) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
851 		p4d_val(*p4d) = _REGION2_ENTRY_EMPTY;
852 }
853 
854 static inline void pud_clear(pud_t *pud)
855 {
856 	if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
857 		pud_val(*pud) = _REGION3_ENTRY_EMPTY;
858 }
859 
860 static inline void pmd_clear(pmd_t *pmdp)
861 {
862 	pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
863 }
864 
865 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
866 {
867 	pte_val(*ptep) = _PAGE_INVALID;
868 }
869 
870 /*
871  * The following pte modification functions only work if
872  * pte_present() is true. Undefined behaviour if not..
873  */
874 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
875 {
876 	pte_val(pte) &= _PAGE_CHG_MASK;
877 	pte_val(pte) |= pgprot_val(newprot);
878 	/*
879 	 * newprot for PAGE_NONE, PAGE_RO, PAGE_RX, PAGE_RW and PAGE_RWX
880 	 * has the invalid bit set, clear it again for readable, young pages
881 	 */
882 	if ((pte_val(pte) & _PAGE_YOUNG) && (pte_val(pte) & _PAGE_READ))
883 		pte_val(pte) &= ~_PAGE_INVALID;
884 	/*
885 	 * newprot for PAGE_RO, PAGE_RX, PAGE_RW and PAGE_RWX has the page
886 	 * protection bit set, clear it again for writable, dirty pages
887 	 */
888 	if ((pte_val(pte) & _PAGE_DIRTY) && (pte_val(pte) & _PAGE_WRITE))
889 		pte_val(pte) &= ~_PAGE_PROTECT;
890 	return pte;
891 }
892 
893 static inline pte_t pte_wrprotect(pte_t pte)
894 {
895 	pte_val(pte) &= ~_PAGE_WRITE;
896 	pte_val(pte) |= _PAGE_PROTECT;
897 	return pte;
898 }
899 
900 static inline pte_t pte_mkwrite(pte_t pte)
901 {
902 	pte_val(pte) |= _PAGE_WRITE;
903 	if (pte_val(pte) & _PAGE_DIRTY)
904 		pte_val(pte) &= ~_PAGE_PROTECT;
905 	return pte;
906 }
907 
908 static inline pte_t pte_mkclean(pte_t pte)
909 {
910 	pte_val(pte) &= ~_PAGE_DIRTY;
911 	pte_val(pte) |= _PAGE_PROTECT;
912 	return pte;
913 }
914 
915 static inline pte_t pte_mkdirty(pte_t pte)
916 {
917 	pte_val(pte) |= _PAGE_DIRTY | _PAGE_SOFT_DIRTY;
918 	if (pte_val(pte) & _PAGE_WRITE)
919 		pte_val(pte) &= ~_PAGE_PROTECT;
920 	return pte;
921 }
922 
923 static inline pte_t pte_mkold(pte_t pte)
924 {
925 	pte_val(pte) &= ~_PAGE_YOUNG;
926 	pte_val(pte) |= _PAGE_INVALID;
927 	return pte;
928 }
929 
930 static inline pte_t pte_mkyoung(pte_t pte)
931 {
932 	pte_val(pte) |= _PAGE_YOUNG;
933 	if (pte_val(pte) & _PAGE_READ)
934 		pte_val(pte) &= ~_PAGE_INVALID;
935 	return pte;
936 }
937 
938 static inline pte_t pte_mkspecial(pte_t pte)
939 {
940 	pte_val(pte) |= _PAGE_SPECIAL;
941 	return pte;
942 }
943 
944 #ifdef CONFIG_HUGETLB_PAGE
945 static inline pte_t pte_mkhuge(pte_t pte)
946 {
947 	pte_val(pte) |= _PAGE_LARGE;
948 	return pte;
949 }
950 #endif
951 
952 #define IPTE_GLOBAL	0
953 #define	IPTE_LOCAL	1
954 
955 #define IPTE_NODAT	0x400
956 #define IPTE_GUEST_ASCE	0x800
957 
958 static inline void __ptep_ipte(unsigned long address, pte_t *ptep,
959 			       unsigned long opt, unsigned long asce,
960 			       int local)
961 {
962 	unsigned long pto = (unsigned long) ptep;
963 
964 	if (__builtin_constant_p(opt) && opt == 0) {
965 		/* Invalidation + TLB flush for the pte */
966 		asm volatile(
967 			"	.insn	rrf,0xb2210000,%[r1],%[r2],0,%[m4]"
968 			: "+m" (*ptep) : [r1] "a" (pto), [r2] "a" (address),
969 			  [m4] "i" (local));
970 		return;
971 	}
972 
973 	/* Invalidate ptes with options + TLB flush of the ptes */
974 	opt = opt | (asce & _ASCE_ORIGIN);
975 	asm volatile(
976 		"	.insn	rrf,0xb2210000,%[r1],%[r2],%[r3],%[m4]"
977 		: [r2] "+a" (address), [r3] "+a" (opt)
978 		: [r1] "a" (pto), [m4] "i" (local) : "memory");
979 }
980 
981 static inline void __ptep_ipte_range(unsigned long address, int nr,
982 				     pte_t *ptep, int local)
983 {
984 	unsigned long pto = (unsigned long) ptep;
985 
986 	/* Invalidate a range of ptes + TLB flush of the ptes */
987 	do {
988 		asm volatile(
989 			"       .insn rrf,0xb2210000,%[r1],%[r2],%[r3],%[m4]"
990 			: [r2] "+a" (address), [r3] "+a" (nr)
991 			: [r1] "a" (pto), [m4] "i" (local) : "memory");
992 	} while (nr != 255);
993 }
994 
995 /*
996  * This is hard to understand. ptep_get_and_clear and ptep_clear_flush
997  * both clear the TLB for the unmapped pte. The reason is that
998  * ptep_get_and_clear is used in common code (e.g. change_pte_range)
999  * to modify an active pte. The sequence is
1000  *   1) ptep_get_and_clear
1001  *   2) set_pte_at
1002  *   3) flush_tlb_range
1003  * On s390 the tlb needs to get flushed with the modification of the pte
1004  * if the pte is active. The only way how this can be implemented is to
1005  * have ptep_get_and_clear do the tlb flush. In exchange flush_tlb_range
1006  * is a nop.
1007  */
1008 pte_t ptep_xchg_direct(struct mm_struct *, unsigned long, pte_t *, pte_t);
1009 pte_t ptep_xchg_lazy(struct mm_struct *, unsigned long, pte_t *, pte_t);
1010 
1011 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
1012 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
1013 					    unsigned long addr, pte_t *ptep)
1014 {
1015 	pte_t pte = *ptep;
1016 
1017 	pte = ptep_xchg_direct(vma->vm_mm, addr, ptep, pte_mkold(pte));
1018 	return pte_young(pte);
1019 }
1020 
1021 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
1022 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
1023 					 unsigned long address, pte_t *ptep)
1024 {
1025 	return ptep_test_and_clear_young(vma, address, ptep);
1026 }
1027 
1028 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
1029 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
1030 				       unsigned long addr, pte_t *ptep)
1031 {
1032 	return ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID));
1033 }
1034 
1035 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
1036 pte_t ptep_modify_prot_start(struct mm_struct *, unsigned long, pte_t *);
1037 void ptep_modify_prot_commit(struct mm_struct *, unsigned long, pte_t *, pte_t);
1038 
1039 #define __HAVE_ARCH_PTEP_CLEAR_FLUSH
1040 static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
1041 				     unsigned long addr, pte_t *ptep)
1042 {
1043 	return ptep_xchg_direct(vma->vm_mm, addr, ptep, __pte(_PAGE_INVALID));
1044 }
1045 
1046 /*
1047  * The batched pte unmap code uses ptep_get_and_clear_full to clear the
1048  * ptes. Here an optimization is possible. tlb_gather_mmu flushes all
1049  * tlbs of an mm if it can guarantee that the ptes of the mm_struct
1050  * cannot be accessed while the batched unmap is running. In this case
1051  * full==1 and a simple pte_clear is enough. See tlb.h.
1052  */
1053 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
1054 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
1055 					    unsigned long addr,
1056 					    pte_t *ptep, int full)
1057 {
1058 	if (full) {
1059 		pte_t pte = *ptep;
1060 		*ptep = __pte(_PAGE_INVALID);
1061 		return pte;
1062 	}
1063 	return ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID));
1064 }
1065 
1066 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
1067 static inline void ptep_set_wrprotect(struct mm_struct *mm,
1068 				      unsigned long addr, pte_t *ptep)
1069 {
1070 	pte_t pte = *ptep;
1071 
1072 	if (pte_write(pte))
1073 		ptep_xchg_lazy(mm, addr, ptep, pte_wrprotect(pte));
1074 }
1075 
1076 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
1077 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
1078 					unsigned long addr, pte_t *ptep,
1079 					pte_t entry, int dirty)
1080 {
1081 	if (pte_same(*ptep, entry))
1082 		return 0;
1083 	ptep_xchg_direct(vma->vm_mm, addr, ptep, entry);
1084 	return 1;
1085 }
1086 
1087 /*
1088  * Additional functions to handle KVM guest page tables
1089  */
1090 void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
1091 		     pte_t *ptep, pte_t entry);
1092 void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
1093 void ptep_notify(struct mm_struct *mm, unsigned long addr,
1094 		 pte_t *ptep, unsigned long bits);
1095 int ptep_force_prot(struct mm_struct *mm, unsigned long gaddr,
1096 		    pte_t *ptep, int prot, unsigned long bit);
1097 void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
1098 		     pte_t *ptep , int reset);
1099 void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
1100 int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
1101 		    pte_t *sptep, pte_t *tptep, pte_t pte);
1102 void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep);
1103 
1104 bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long address);
1105 int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
1106 			  unsigned char key, bool nq);
1107 int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
1108 			       unsigned char key, unsigned char *oldkey,
1109 			       bool nq, bool mr, bool mc);
1110 int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr);
1111 int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
1112 			  unsigned char *key);
1113 
1114 int set_pgste_bits(struct mm_struct *mm, unsigned long addr,
1115 				unsigned long bits, unsigned long value);
1116 int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep);
1117 int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
1118 			unsigned long *oldpte, unsigned long *oldpgste);
1119 
1120 /*
1121  * Certain architectures need to do special things when PTEs
1122  * within a page table are directly modified.  Thus, the following
1123  * hook is made available.
1124  */
1125 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
1126 			      pte_t *ptep, pte_t entry)
1127 {
1128 	if (!MACHINE_HAS_NX)
1129 		pte_val(entry) &= ~_PAGE_NOEXEC;
1130 	if (pte_present(entry))
1131 		pte_val(entry) &= ~_PAGE_UNUSED;
1132 	if (mm_has_pgste(mm))
1133 		ptep_set_pte_at(mm, addr, ptep, entry);
1134 	else
1135 		*ptep = entry;
1136 }
1137 
1138 /*
1139  * Conversion functions: convert a page and protection to a page entry,
1140  * and a page entry and page directory to the page they refer to.
1141  */
1142 static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
1143 {
1144 	pte_t __pte;
1145 	pte_val(__pte) = physpage + pgprot_val(pgprot);
1146 	return pte_mkyoung(__pte);
1147 }
1148 
1149 static inline pte_t mk_pte(struct page *page, pgprot_t pgprot)
1150 {
1151 	unsigned long physpage = page_to_phys(page);
1152 	pte_t __pte = mk_pte_phys(physpage, pgprot);
1153 
1154 	if (pte_write(__pte) && PageDirty(page))
1155 		__pte = pte_mkdirty(__pte);
1156 	return __pte;
1157 }
1158 
1159 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
1160 #define p4d_index(address) (((address) >> P4D_SHIFT) & (PTRS_PER_P4D-1))
1161 #define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
1162 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
1163 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
1164 
1165 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
1166 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
1167 
1168 #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
1169 #define pud_deref(pud) (pud_val(pud) & _REGION_ENTRY_ORIGIN)
1170 #define p4d_deref(pud) (p4d_val(pud) & _REGION_ENTRY_ORIGIN)
1171 #define pgd_deref(pgd) (pgd_val(pgd) & _REGION_ENTRY_ORIGIN)
1172 
1173 static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
1174 {
1175 	p4d_t *p4d = (p4d_t *) pgd;
1176 
1177 	if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R1)
1178 		p4d = (p4d_t *) pgd_deref(*pgd);
1179 	return p4d + p4d_index(address);
1180 }
1181 
1182 static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
1183 {
1184 	pud_t *pud = (pud_t *) p4d;
1185 
1186 	if ((p4d_val(*p4d) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
1187 		pud = (pud_t *) p4d_deref(*p4d);
1188 	return pud + pud_index(address);
1189 }
1190 
1191 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
1192 {
1193 	pmd_t *pmd = (pmd_t *) pud;
1194 
1195 	if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
1196 		pmd = (pmd_t *) pud_deref(*pud);
1197 	return pmd + pmd_index(address);
1198 }
1199 
1200 #define pfn_pte(pfn,pgprot) mk_pte_phys(__pa((pfn) << PAGE_SHIFT),(pgprot))
1201 #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
1202 #define pte_page(x) pfn_to_page(pte_pfn(x))
1203 
1204 #define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd))
1205 #define pud_page(pud) pfn_to_page(pud_pfn(pud))
1206 #define p4d_page(pud) pfn_to_page(p4d_pfn(p4d))
1207 
1208 /* Find an entry in the lowest level page table.. */
1209 #define pte_offset(pmd, addr) ((pte_t *) pmd_deref(*(pmd)) + pte_index(addr))
1210 #define pte_offset_kernel(pmd, address) pte_offset(pmd,address)
1211 #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
1212 #define pte_unmap(pte) do { } while (0)
1213 
1214 static inline pmd_t pmd_wrprotect(pmd_t pmd)
1215 {
1216 	pmd_val(pmd) &= ~_SEGMENT_ENTRY_WRITE;
1217 	pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
1218 	return pmd;
1219 }
1220 
1221 static inline pmd_t pmd_mkwrite(pmd_t pmd)
1222 {
1223 	pmd_val(pmd) |= _SEGMENT_ENTRY_WRITE;
1224 	if (pmd_large(pmd) && !(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY))
1225 		return pmd;
1226 	pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
1227 	return pmd;
1228 }
1229 
1230 static inline pmd_t pmd_mkclean(pmd_t pmd)
1231 {
1232 	if (pmd_large(pmd)) {
1233 		pmd_val(pmd) &= ~_SEGMENT_ENTRY_DIRTY;
1234 		pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
1235 	}
1236 	return pmd;
1237 }
1238 
1239 static inline pmd_t pmd_mkdirty(pmd_t pmd)
1240 {
1241 	if (pmd_large(pmd)) {
1242 		pmd_val(pmd) |= _SEGMENT_ENTRY_DIRTY |
1243 				_SEGMENT_ENTRY_SOFT_DIRTY;
1244 		if (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE)
1245 			pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
1246 	}
1247 	return pmd;
1248 }
1249 
1250 static inline pud_t pud_wrprotect(pud_t pud)
1251 {
1252 	pud_val(pud) &= ~_REGION3_ENTRY_WRITE;
1253 	pud_val(pud) |= _REGION_ENTRY_PROTECT;
1254 	return pud;
1255 }
1256 
1257 static inline pud_t pud_mkwrite(pud_t pud)
1258 {
1259 	pud_val(pud) |= _REGION3_ENTRY_WRITE;
1260 	if (pud_large(pud) && !(pud_val(pud) & _REGION3_ENTRY_DIRTY))
1261 		return pud;
1262 	pud_val(pud) &= ~_REGION_ENTRY_PROTECT;
1263 	return pud;
1264 }
1265 
1266 static inline pud_t pud_mkclean(pud_t pud)
1267 {
1268 	if (pud_large(pud)) {
1269 		pud_val(pud) &= ~_REGION3_ENTRY_DIRTY;
1270 		pud_val(pud) |= _REGION_ENTRY_PROTECT;
1271 	}
1272 	return pud;
1273 }
1274 
1275 static inline pud_t pud_mkdirty(pud_t pud)
1276 {
1277 	if (pud_large(pud)) {
1278 		pud_val(pud) |= _REGION3_ENTRY_DIRTY |
1279 				_REGION3_ENTRY_SOFT_DIRTY;
1280 		if (pud_val(pud) & _REGION3_ENTRY_WRITE)
1281 			pud_val(pud) &= ~_REGION_ENTRY_PROTECT;
1282 	}
1283 	return pud;
1284 }
1285 
1286 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE)
1287 static inline unsigned long massage_pgprot_pmd(pgprot_t pgprot)
1288 {
1289 	/*
1290 	 * pgprot is PAGE_NONE, PAGE_RO, PAGE_RX, PAGE_RW or PAGE_RWX
1291 	 * (see __Pxxx / __Sxxx). Convert to segment table entry format.
1292 	 */
1293 	if (pgprot_val(pgprot) == pgprot_val(PAGE_NONE))
1294 		return pgprot_val(SEGMENT_NONE);
1295 	if (pgprot_val(pgprot) == pgprot_val(PAGE_RO))
1296 		return pgprot_val(SEGMENT_RO);
1297 	if (pgprot_val(pgprot) == pgprot_val(PAGE_RX))
1298 		return pgprot_val(SEGMENT_RX);
1299 	if (pgprot_val(pgprot) == pgprot_val(PAGE_RW))
1300 		return pgprot_val(SEGMENT_RW);
1301 	return pgprot_val(SEGMENT_RWX);
1302 }
1303 
1304 static inline pmd_t pmd_mkyoung(pmd_t pmd)
1305 {
1306 	if (pmd_large(pmd)) {
1307 		pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
1308 		if (pmd_val(pmd) & _SEGMENT_ENTRY_READ)
1309 			pmd_val(pmd) &= ~_SEGMENT_ENTRY_INVALID;
1310 	}
1311 	return pmd;
1312 }
1313 
1314 static inline pmd_t pmd_mkold(pmd_t pmd)
1315 {
1316 	if (pmd_large(pmd)) {
1317 		pmd_val(pmd) &= ~_SEGMENT_ENTRY_YOUNG;
1318 		pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
1319 	}
1320 	return pmd;
1321 }
1322 
1323 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
1324 {
1325 	if (pmd_large(pmd)) {
1326 		pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN_LARGE |
1327 			_SEGMENT_ENTRY_DIRTY | _SEGMENT_ENTRY_YOUNG |
1328 			_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_SOFT_DIRTY;
1329 		pmd_val(pmd) |= massage_pgprot_pmd(newprot);
1330 		if (!(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY))
1331 			pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
1332 		if (!(pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG))
1333 			pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
1334 		return pmd;
1335 	}
1336 	pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN;
1337 	pmd_val(pmd) |= massage_pgprot_pmd(newprot);
1338 	return pmd;
1339 }
1340 
1341 static inline pmd_t mk_pmd_phys(unsigned long physpage, pgprot_t pgprot)
1342 {
1343 	pmd_t __pmd;
1344 	pmd_val(__pmd) = physpage + massage_pgprot_pmd(pgprot);
1345 	return __pmd;
1346 }
1347 
1348 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLB_PAGE */
1349 
1350 static inline void __pmdp_csp(pmd_t *pmdp)
1351 {
1352 	csp((unsigned int *)pmdp + 1, pmd_val(*pmdp),
1353 	    pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
1354 }
1355 
1356 #define IDTE_GLOBAL	0
1357 #define IDTE_LOCAL	1
1358 
1359 #define IDTE_PTOA	0x0800
1360 #define IDTE_NODAT	0x1000
1361 #define IDTE_GUEST_ASCE	0x2000
1362 
1363 static inline void __pmdp_idte(unsigned long addr, pmd_t *pmdp,
1364 			       unsigned long opt, unsigned long asce,
1365 			       int local)
1366 {
1367 	unsigned long sto;
1368 
1369 	sto = (unsigned long) pmdp - pmd_index(addr) * sizeof(pmd_t);
1370 	if (__builtin_constant_p(opt) && opt == 0) {
1371 		/* flush without guest asce */
1372 		asm volatile(
1373 			"	.insn	rrf,0xb98e0000,%[r1],%[r2],0,%[m4]"
1374 			: "+m" (*pmdp)
1375 			: [r1] "a" (sto), [r2] "a" ((addr & HPAGE_MASK)),
1376 			  [m4] "i" (local)
1377 			: "cc" );
1378 	} else {
1379 		/* flush with guest asce */
1380 		asm volatile(
1381 			"	.insn	rrf,0xb98e0000,%[r1],%[r2],%[r3],%[m4]"
1382 			: "+m" (*pmdp)
1383 			: [r1] "a" (sto), [r2] "a" ((addr & HPAGE_MASK) | opt),
1384 			  [r3] "a" (asce), [m4] "i" (local)
1385 			: "cc" );
1386 	}
1387 }
1388 
1389 static inline void __pudp_idte(unsigned long addr, pud_t *pudp,
1390 			       unsigned long opt, unsigned long asce,
1391 			       int local)
1392 {
1393 	unsigned long r3o;
1394 
1395 	r3o = (unsigned long) pudp - pud_index(addr) * sizeof(pud_t);
1396 	r3o |= _ASCE_TYPE_REGION3;
1397 	if (__builtin_constant_p(opt) && opt == 0) {
1398 		/* flush without guest asce */
1399 		asm volatile(
1400 			"	.insn	rrf,0xb98e0000,%[r1],%[r2],0,%[m4]"
1401 			: "+m" (*pudp)
1402 			: [r1] "a" (r3o), [r2] "a" ((addr & PUD_MASK)),
1403 			  [m4] "i" (local)
1404 			: "cc");
1405 	} else {
1406 		/* flush with guest asce */
1407 		asm volatile(
1408 			"	.insn	rrf,0xb98e0000,%[r1],%[r2],%[r3],%[m4]"
1409 			: "+m" (*pudp)
1410 			: [r1] "a" (r3o), [r2] "a" ((addr & PUD_MASK) | opt),
1411 			  [r3] "a" (asce), [m4] "i" (local)
1412 			: "cc" );
1413 	}
1414 }
1415 
1416 pmd_t pmdp_xchg_direct(struct mm_struct *, unsigned long, pmd_t *, pmd_t);
1417 pmd_t pmdp_xchg_lazy(struct mm_struct *, unsigned long, pmd_t *, pmd_t);
1418 pud_t pudp_xchg_direct(struct mm_struct *, unsigned long, pud_t *, pud_t);
1419 
1420 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1421 
1422 #define __HAVE_ARCH_PGTABLE_DEPOSIT
1423 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
1424 				pgtable_t pgtable);
1425 
1426 #define __HAVE_ARCH_PGTABLE_WITHDRAW
1427 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
1428 
1429 #define  __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
1430 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
1431 					unsigned long addr, pmd_t *pmdp,
1432 					pmd_t entry, int dirty)
1433 {
1434 	VM_BUG_ON(addr & ~HPAGE_MASK);
1435 
1436 	entry = pmd_mkyoung(entry);
1437 	if (dirty)
1438 		entry = pmd_mkdirty(entry);
1439 	if (pmd_val(*pmdp) == pmd_val(entry))
1440 		return 0;
1441 	pmdp_xchg_direct(vma->vm_mm, addr, pmdp, entry);
1442 	return 1;
1443 }
1444 
1445 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1446 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
1447 					    unsigned long addr, pmd_t *pmdp)
1448 {
1449 	pmd_t pmd = *pmdp;
1450 
1451 	pmd = pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd_mkold(pmd));
1452 	return pmd_young(pmd);
1453 }
1454 
1455 #define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
1456 static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
1457 					 unsigned long addr, pmd_t *pmdp)
1458 {
1459 	VM_BUG_ON(addr & ~HPAGE_MASK);
1460 	return pmdp_test_and_clear_young(vma, addr, pmdp);
1461 }
1462 
1463 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
1464 			      pmd_t *pmdp, pmd_t entry)
1465 {
1466 	if (!MACHINE_HAS_NX)
1467 		pmd_val(entry) &= ~_SEGMENT_ENTRY_NOEXEC;
1468 	*pmdp = entry;
1469 }
1470 
1471 static inline pmd_t pmd_mkhuge(pmd_t pmd)
1472 {
1473 	pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
1474 	pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
1475 	pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
1476 	return pmd;
1477 }
1478 
1479 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
1480 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
1481 					    unsigned long addr, pmd_t *pmdp)
1482 {
1483 	return pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
1484 }
1485 
1486 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
1487 static inline pmd_t pmdp_huge_get_and_clear_full(struct mm_struct *mm,
1488 						 unsigned long addr,
1489 						 pmd_t *pmdp, int full)
1490 {
1491 	if (full) {
1492 		pmd_t pmd = *pmdp;
1493 		*pmdp = __pmd(_SEGMENT_ENTRY_EMPTY);
1494 		return pmd;
1495 	}
1496 	return pmdp_xchg_lazy(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
1497 }
1498 
1499 #define __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
1500 static inline pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
1501 					  unsigned long addr, pmd_t *pmdp)
1502 {
1503 	return pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
1504 }
1505 
1506 #define __HAVE_ARCH_PMDP_INVALIDATE
1507 static inline pmd_t pmdp_invalidate(struct vm_area_struct *vma,
1508 				   unsigned long addr, pmd_t *pmdp)
1509 {
1510 	pmd_t pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
1511 
1512 	return pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd);
1513 }
1514 
1515 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1516 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1517 				      unsigned long addr, pmd_t *pmdp)
1518 {
1519 	pmd_t pmd = *pmdp;
1520 
1521 	if (pmd_write(pmd))
1522 		pmd = pmdp_xchg_lazy(mm, addr, pmdp, pmd_wrprotect(pmd));
1523 }
1524 
1525 static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
1526 					unsigned long address,
1527 					pmd_t *pmdp)
1528 {
1529 	return pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
1530 }
1531 #define pmdp_collapse_flush pmdp_collapse_flush
1532 
1533 #define pfn_pmd(pfn, pgprot)	mk_pmd_phys(__pa((pfn) << PAGE_SHIFT), (pgprot))
1534 #define mk_pmd(page, pgprot)	pfn_pmd(page_to_pfn(page), (pgprot))
1535 
1536 static inline int pmd_trans_huge(pmd_t pmd)
1537 {
1538 	return pmd_val(pmd) & _SEGMENT_ENTRY_LARGE;
1539 }
1540 
1541 #define has_transparent_hugepage has_transparent_hugepage
1542 static inline int has_transparent_hugepage(void)
1543 {
1544 	return MACHINE_HAS_EDAT1 ? 1 : 0;
1545 }
1546 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1547 
1548 /*
1549  * 64 bit swap entry format:
1550  * A page-table entry has some bits we have to treat in a special way.
1551  * Bits 52 and bit 55 have to be zero, otherwise a specification
1552  * exception will occur instead of a page translation exception. The
1553  * specification exception has the bad habit not to store necessary
1554  * information in the lowcore.
1555  * Bits 54 and 63 are used to indicate the page type.
1556  * A swap pte is indicated by bit pattern (pte & 0x201) == 0x200
1557  * This leaves the bits 0-51 and bits 56-62 to store type and offset.
1558  * We use the 5 bits from 57-61 for the type and the 52 bits from 0-51
1559  * for the offset.
1560  * |			  offset			|01100|type |00|
1561  * |0000000000111111111122222222223333333333444444444455|55555|55566|66|
1562  * |0123456789012345678901234567890123456789012345678901|23456|78901|23|
1563  */
1564 
1565 #define __SWP_OFFSET_MASK	((1UL << 52) - 1)
1566 #define __SWP_OFFSET_SHIFT	12
1567 #define __SWP_TYPE_MASK		((1UL << 5) - 1)
1568 #define __SWP_TYPE_SHIFT	2
1569 
1570 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
1571 {
1572 	pte_t pte;
1573 
1574 	pte_val(pte) = _PAGE_INVALID | _PAGE_PROTECT;
1575 	pte_val(pte) |= (offset & __SWP_OFFSET_MASK) << __SWP_OFFSET_SHIFT;
1576 	pte_val(pte) |= (type & __SWP_TYPE_MASK) << __SWP_TYPE_SHIFT;
1577 	return pte;
1578 }
1579 
1580 static inline unsigned long __swp_type(swp_entry_t entry)
1581 {
1582 	return (entry.val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK;
1583 }
1584 
1585 static inline unsigned long __swp_offset(swp_entry_t entry)
1586 {
1587 	return (entry.val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK;
1588 }
1589 
1590 static inline swp_entry_t __swp_entry(unsigned long type, unsigned long offset)
1591 {
1592 	return (swp_entry_t) { pte_val(mk_swap_pte(type, offset)) };
1593 }
1594 
1595 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1596 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
1597 
1598 #define kern_addr_valid(addr)   (1)
1599 
1600 extern int vmem_add_mapping(unsigned long start, unsigned long size);
1601 extern int vmem_remove_mapping(unsigned long start, unsigned long size);
1602 extern int s390_enable_sie(void);
1603 extern int s390_enable_skey(void);
1604 extern void s390_reset_cmma(struct mm_struct *mm);
1605 
1606 /* s390 has a private copy of get unmapped area to deal with cache synonyms */
1607 #define HAVE_ARCH_UNMAPPED_AREA
1608 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
1609 
1610 /*
1611  * No page table caches to initialise
1612  */
1613 static inline void pgtable_cache_init(void) { }
1614 static inline void check_pgt_cache(void) { }
1615 
1616 #include <asm-generic/pgtable.h>
1617 
1618 #endif /* _S390_PAGE_H */
1619