1 #ifndef _ASM_POWERPC_BOOK3S_64_MMU_HASH_H_
2 #define _ASM_POWERPC_BOOK3S_64_MMU_HASH_H_
3 /*
4  * PowerPC64 memory management structures
5  *
6  * Dave Engebretsen & Mike Corrigan <{engebret|mikejc}@us.ibm.com>
7  *   PPC64 rework.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or (at your option) any later version.
13  */
14 
15 #include <asm/page.h>
16 #include <asm/bug.h>
17 #include <asm/asm-const.h>
18 
19 /*
20  * This is necessary to get the definition of PGTABLE_RANGE which we
21  * need for various slices related matters. Note that this isn't the
22  * complete pgtable.h but only a portion of it.
23  */
24 #include <asm/book3s/64/pgtable.h>
25 #include <asm/bug.h>
26 #include <asm/processor.h>
27 #include <asm/cpu_has_feature.h>
28 
29 /*
30  * SLB
31  */
32 
33 #define SLB_NUM_BOLTED		3
34 #define SLB_CACHE_ENTRIES	8
35 #define SLB_MIN_SIZE		32
36 
37 /* Bits in the SLB ESID word */
38 #define SLB_ESID_V		ASM_CONST(0x0000000008000000) /* valid */
39 
40 /* Bits in the SLB VSID word */
41 #define SLB_VSID_SHIFT		12
42 #define SLB_VSID_SHIFT_256M	SLB_VSID_SHIFT
43 #define SLB_VSID_SHIFT_1T	24
44 #define SLB_VSID_SSIZE_SHIFT	62
45 #define SLB_VSID_B		ASM_CONST(0xc000000000000000)
46 #define SLB_VSID_B_256M		ASM_CONST(0x0000000000000000)
47 #define SLB_VSID_B_1T		ASM_CONST(0x4000000000000000)
48 #define SLB_VSID_KS		ASM_CONST(0x0000000000000800)
49 #define SLB_VSID_KP		ASM_CONST(0x0000000000000400)
50 #define SLB_VSID_N		ASM_CONST(0x0000000000000200) /* no-execute */
51 #define SLB_VSID_L		ASM_CONST(0x0000000000000100)
52 #define SLB_VSID_C		ASM_CONST(0x0000000000000080) /* class */
53 #define SLB_VSID_LP		ASM_CONST(0x0000000000000030)
54 #define SLB_VSID_LP_00		ASM_CONST(0x0000000000000000)
55 #define SLB_VSID_LP_01		ASM_CONST(0x0000000000000010)
56 #define SLB_VSID_LP_10		ASM_CONST(0x0000000000000020)
57 #define SLB_VSID_LP_11		ASM_CONST(0x0000000000000030)
58 #define SLB_VSID_LLP		(SLB_VSID_L|SLB_VSID_LP)
59 
60 #define SLB_VSID_KERNEL		(SLB_VSID_KP)
61 #define SLB_VSID_USER		(SLB_VSID_KP|SLB_VSID_KS|SLB_VSID_C)
62 
63 #define SLBIE_C			(0x08000000)
64 #define SLBIE_SSIZE_SHIFT	25
65 
66 /*
67  * Hash table
68  */
69 
70 #define HPTES_PER_GROUP 8
71 
72 #define HPTE_V_SSIZE_SHIFT	62
73 #define HPTE_V_AVPN_SHIFT	7
74 #define HPTE_V_COMMON_BITS	ASM_CONST(0x000fffffffffffff)
75 #define HPTE_V_AVPN		ASM_CONST(0x3fffffffffffff80)
76 #define HPTE_V_AVPN_3_0		ASM_CONST(0x000fffffffffff80)
77 #define HPTE_V_AVPN_VAL(x)	(((x) & HPTE_V_AVPN) >> HPTE_V_AVPN_SHIFT)
78 #define HPTE_V_COMPARE(x,y)	(!(((x) ^ (y)) & 0xffffffffffffff80UL))
79 #define HPTE_V_BOLTED		ASM_CONST(0x0000000000000010)
80 #define HPTE_V_LOCK		ASM_CONST(0x0000000000000008)
81 #define HPTE_V_LARGE		ASM_CONST(0x0000000000000004)
82 #define HPTE_V_SECONDARY	ASM_CONST(0x0000000000000002)
83 #define HPTE_V_VALID		ASM_CONST(0x0000000000000001)
84 
85 /*
86  * ISA 3.0 has a different HPTE format.
87  */
88 #define HPTE_R_3_0_SSIZE_SHIFT	58
89 #define HPTE_R_3_0_SSIZE_MASK	(3ull << HPTE_R_3_0_SSIZE_SHIFT)
90 #define HPTE_R_PP0		ASM_CONST(0x8000000000000000)
91 #define HPTE_R_TS		ASM_CONST(0x4000000000000000)
92 #define HPTE_R_KEY_HI		ASM_CONST(0x3000000000000000)
93 #define HPTE_R_KEY_BIT0		ASM_CONST(0x2000000000000000)
94 #define HPTE_R_KEY_BIT1		ASM_CONST(0x1000000000000000)
95 #define HPTE_R_RPN_SHIFT	12
96 #define HPTE_R_RPN		ASM_CONST(0x0ffffffffffff000)
97 #define HPTE_R_RPN_3_0		ASM_CONST(0x01fffffffffff000)
98 #define HPTE_R_PP		ASM_CONST(0x0000000000000003)
99 #define HPTE_R_PPP		ASM_CONST(0x8000000000000003)
100 #define HPTE_R_N		ASM_CONST(0x0000000000000004)
101 #define HPTE_R_G		ASM_CONST(0x0000000000000008)
102 #define HPTE_R_M		ASM_CONST(0x0000000000000010)
103 #define HPTE_R_I		ASM_CONST(0x0000000000000020)
104 #define HPTE_R_W		ASM_CONST(0x0000000000000040)
105 #define HPTE_R_WIMG		ASM_CONST(0x0000000000000078)
106 #define HPTE_R_C		ASM_CONST(0x0000000000000080)
107 #define HPTE_R_R		ASM_CONST(0x0000000000000100)
108 #define HPTE_R_KEY_LO		ASM_CONST(0x0000000000000e00)
109 #define HPTE_R_KEY_BIT2		ASM_CONST(0x0000000000000800)
110 #define HPTE_R_KEY_BIT3		ASM_CONST(0x0000000000000400)
111 #define HPTE_R_KEY_BIT4		ASM_CONST(0x0000000000000200)
112 #define HPTE_R_KEY		(HPTE_R_KEY_LO | HPTE_R_KEY_HI)
113 
114 #define HPTE_V_1TB_SEG		ASM_CONST(0x4000000000000000)
115 #define HPTE_V_VRMA_MASK	ASM_CONST(0x4001ffffff000000)
116 
117 /* Values for PP (assumes Ks=0, Kp=1) */
118 #define PP_RWXX	0	/* Supervisor read/write, User none */
119 #define PP_RWRX 1	/* Supervisor read/write, User read */
120 #define PP_RWRW 2	/* Supervisor read/write, User read/write */
121 #define PP_RXRX 3	/* Supervisor read,       User read */
122 #define PP_RXXX	(HPTE_R_PP0 | 2)	/* Supervisor read, user none */
123 
124 /* Fields for tlbiel instruction in architecture 2.06 */
125 #define TLBIEL_INVAL_SEL_MASK	0xc00	/* invalidation selector */
126 #define  TLBIEL_INVAL_PAGE	0x000	/* invalidate a single page */
127 #define  TLBIEL_INVAL_SET_LPID	0x800	/* invalidate a set for current LPID */
128 #define  TLBIEL_INVAL_SET	0xc00	/* invalidate a set for all LPIDs */
129 #define TLBIEL_INVAL_SET_MASK	0xfff000	/* set number to inval. */
130 #define TLBIEL_INVAL_SET_SHIFT	12
131 
132 #define POWER7_TLB_SETS		128	/* # sets in POWER7 TLB */
133 #define POWER8_TLB_SETS		512	/* # sets in POWER8 TLB */
134 #define POWER9_TLB_SETS_HASH	256	/* # sets in POWER9 TLB Hash mode */
135 #define POWER9_TLB_SETS_RADIX	128	/* # sets in POWER9 TLB Radix mode */
136 
137 #ifndef __ASSEMBLY__
138 
139 struct mmu_hash_ops {
140 	void            (*hpte_invalidate)(unsigned long slot,
141 					   unsigned long vpn,
142 					   int bpsize, int apsize,
143 					   int ssize, int local);
144 	long		(*hpte_updatepp)(unsigned long slot,
145 					 unsigned long newpp,
146 					 unsigned long vpn,
147 					 int bpsize, int apsize,
148 					 int ssize, unsigned long flags);
149 	void            (*hpte_updateboltedpp)(unsigned long newpp,
150 					       unsigned long ea,
151 					       int psize, int ssize);
152 	long		(*hpte_insert)(unsigned long hpte_group,
153 				       unsigned long vpn,
154 				       unsigned long prpn,
155 				       unsigned long rflags,
156 				       unsigned long vflags,
157 				       int psize, int apsize,
158 				       int ssize);
159 	long		(*hpte_remove)(unsigned long hpte_group);
160 	int             (*hpte_removebolted)(unsigned long ea,
161 					     int psize, int ssize);
162 	void		(*flush_hash_range)(unsigned long number, int local);
163 	void		(*hugepage_invalidate)(unsigned long vsid,
164 					       unsigned long addr,
165 					       unsigned char *hpte_slot_array,
166 					       int psize, int ssize, int local);
167 	int		(*resize_hpt)(unsigned long shift);
168 	/*
169 	 * Special for kexec.
170 	 * To be called in real mode with interrupts disabled. No locks are
171 	 * taken as such, concurrent access on pre POWER5 hardware could result
172 	 * in a deadlock.
173 	 * The linear mapping is destroyed as well.
174 	 */
175 	void		(*hpte_clear_all)(void);
176 };
177 extern struct mmu_hash_ops mmu_hash_ops;
178 
179 struct hash_pte {
180 	__be64 v;
181 	__be64 r;
182 };
183 
184 extern struct hash_pte *htab_address;
185 extern unsigned long htab_size_bytes;
186 extern unsigned long htab_hash_mask;
187 
188 
189 static inline int shift_to_mmu_psize(unsigned int shift)
190 {
191 	int psize;
192 
193 	for (psize = 0; psize < MMU_PAGE_COUNT; ++psize)
194 		if (mmu_psize_defs[psize].shift == shift)
195 			return psize;
196 	return -1;
197 }
198 
199 static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
200 {
201 	if (mmu_psize_defs[mmu_psize].shift)
202 		return mmu_psize_defs[mmu_psize].shift;
203 	BUG();
204 }
205 
206 static inline unsigned long get_sllp_encoding(int psize)
207 {
208 	unsigned long sllp;
209 
210 	sllp = ((mmu_psize_defs[psize].sllp & SLB_VSID_L) >> 6) |
211 		((mmu_psize_defs[psize].sllp & SLB_VSID_LP) >> 4);
212 	return sllp;
213 }
214 
215 #endif /* __ASSEMBLY__ */
216 
217 /*
218  * Segment sizes.
219  * These are the values used by hardware in the B field of
220  * SLB entries and the first dword of MMU hashtable entries.
221  * The B field is 2 bits; the values 2 and 3 are unused and reserved.
222  */
223 #define MMU_SEGSIZE_256M	0
224 #define MMU_SEGSIZE_1T		1
225 
226 /*
227  * encode page number shift.
228  * in order to fit the 78 bit va in a 64 bit variable we shift the va by
229  * 12 bits. This enable us to address upto 76 bit va.
230  * For hpt hash from a va we can ignore the page size bits of va and for
231  * hpte encoding we ignore up to 23 bits of va. So ignoring lower 12 bits ensure
232  * we work in all cases including 4k page size.
233  */
234 #define VPN_SHIFT	12
235 
236 /*
237  * HPTE Large Page (LP) details
238  */
239 #define LP_SHIFT	12
240 #define LP_BITS		8
241 #define LP_MASK(i)	((0xFF >> (i)) << LP_SHIFT)
242 
243 #ifndef __ASSEMBLY__
244 
245 static inline int slb_vsid_shift(int ssize)
246 {
247 	if (ssize == MMU_SEGSIZE_256M)
248 		return SLB_VSID_SHIFT;
249 	return SLB_VSID_SHIFT_1T;
250 }
251 
252 static inline int segment_shift(int ssize)
253 {
254 	if (ssize == MMU_SEGSIZE_256M)
255 		return SID_SHIFT;
256 	return SID_SHIFT_1T;
257 }
258 
259 /*
260  * This array is indexed by the LP field of the HPTE second dword.
261  * Since this field may contain some RPN bits, some entries are
262  * replicated so that we get the same value irrespective of RPN.
263  * The top 4 bits are the page size index (MMU_PAGE_*) for the
264  * actual page size, the bottom 4 bits are the base page size.
265  */
266 extern u8 hpte_page_sizes[1 << LP_BITS];
267 
268 static inline unsigned long __hpte_page_size(unsigned long h, unsigned long l,
269 					     bool is_base_size)
270 {
271 	unsigned int i, lp;
272 
273 	if (!(h & HPTE_V_LARGE))
274 		return 1ul << 12;
275 
276 	/* Look at the 8 bit LP value */
277 	lp = (l >> LP_SHIFT) & ((1 << LP_BITS) - 1);
278 	i = hpte_page_sizes[lp];
279 	if (!i)
280 		return 0;
281 	if (!is_base_size)
282 		i >>= 4;
283 	return 1ul << mmu_psize_defs[i & 0xf].shift;
284 }
285 
286 static inline unsigned long hpte_page_size(unsigned long h, unsigned long l)
287 {
288 	return __hpte_page_size(h, l, 0);
289 }
290 
291 static inline unsigned long hpte_base_page_size(unsigned long h, unsigned long l)
292 {
293 	return __hpte_page_size(h, l, 1);
294 }
295 
296 /*
297  * The current system page and segment sizes
298  */
299 extern int mmu_kernel_ssize;
300 extern int mmu_highuser_ssize;
301 extern u16 mmu_slb_size;
302 extern unsigned long tce_alloc_start, tce_alloc_end;
303 
304 /*
305  * If the processor supports 64k normal pages but not 64k cache
306  * inhibited pages, we have to be prepared to switch processes
307  * to use 4k pages when they create cache-inhibited mappings.
308  * If this is the case, mmu_ci_restrictions will be set to 1.
309  */
310 extern int mmu_ci_restrictions;
311 
312 /*
313  * This computes the AVPN and B fields of the first dword of a HPTE,
314  * for use when we want to match an existing PTE.  The bottom 7 bits
315  * of the returned value are zero.
316  */
317 static inline unsigned long hpte_encode_avpn(unsigned long vpn, int psize,
318 					     int ssize)
319 {
320 	unsigned long v;
321 	/*
322 	 * The AVA field omits the low-order 23 bits of the 78 bits VA.
323 	 * These bits are not needed in the PTE, because the
324 	 * low-order b of these bits are part of the byte offset
325 	 * into the virtual page and, if b < 23, the high-order
326 	 * 23-b of these bits are always used in selecting the
327 	 * PTEGs to be searched
328 	 */
329 	v = (vpn >> (23 - VPN_SHIFT)) & ~(mmu_psize_defs[psize].avpnm);
330 	v <<= HPTE_V_AVPN_SHIFT;
331 	v |= ((unsigned long) ssize) << HPTE_V_SSIZE_SHIFT;
332 	return v;
333 }
334 
335 /*
336  * ISA v3.0 defines a new HPTE format, which differs from the old
337  * format in having smaller AVPN and ARPN fields, and the B field
338  * in the second dword instead of the first.
339  */
340 static inline unsigned long hpte_old_to_new_v(unsigned long v)
341 {
342 	/* trim AVPN, drop B */
343 	return v & HPTE_V_COMMON_BITS;
344 }
345 
346 static inline unsigned long hpte_old_to_new_r(unsigned long v, unsigned long r)
347 {
348 	/* move B field from 1st to 2nd dword, trim ARPN */
349 	return (r & ~HPTE_R_3_0_SSIZE_MASK) |
350 		(((v) >> HPTE_V_SSIZE_SHIFT) << HPTE_R_3_0_SSIZE_SHIFT);
351 }
352 
353 static inline unsigned long hpte_new_to_old_v(unsigned long v, unsigned long r)
354 {
355 	/* insert B field */
356 	return (v & HPTE_V_COMMON_BITS) |
357 		((r & HPTE_R_3_0_SSIZE_MASK) <<
358 		 (HPTE_V_SSIZE_SHIFT - HPTE_R_3_0_SSIZE_SHIFT));
359 }
360 
361 static inline unsigned long hpte_new_to_old_r(unsigned long r)
362 {
363 	/* clear out B field */
364 	return r & ~HPTE_R_3_0_SSIZE_MASK;
365 }
366 
367 static inline unsigned long hpte_get_old_v(struct hash_pte *hptep)
368 {
369 	unsigned long hpte_v;
370 
371 	hpte_v = be64_to_cpu(hptep->v);
372 	if (cpu_has_feature(CPU_FTR_ARCH_300))
373 		hpte_v = hpte_new_to_old_v(hpte_v, be64_to_cpu(hptep->r));
374 	return hpte_v;
375 }
376 
377 /*
378  * This function sets the AVPN and L fields of the HPTE  appropriately
379  * using the base page size and actual page size.
380  */
381 static inline unsigned long hpte_encode_v(unsigned long vpn, int base_psize,
382 					  int actual_psize, int ssize)
383 {
384 	unsigned long v;
385 	v = hpte_encode_avpn(vpn, base_psize, ssize);
386 	if (actual_psize != MMU_PAGE_4K)
387 		v |= HPTE_V_LARGE;
388 	return v;
389 }
390 
391 /*
392  * This function sets the ARPN, and LP fields of the HPTE appropriately
393  * for the page size. We assume the pa is already "clean" that is properly
394  * aligned for the requested page size
395  */
396 static inline unsigned long hpte_encode_r(unsigned long pa, int base_psize,
397 					  int actual_psize)
398 {
399 	/* A 4K page needs no special encoding */
400 	if (actual_psize == MMU_PAGE_4K)
401 		return pa & HPTE_R_RPN;
402 	else {
403 		unsigned int penc = mmu_psize_defs[base_psize].penc[actual_psize];
404 		unsigned int shift = mmu_psize_defs[actual_psize].shift;
405 		return (pa & ~((1ul << shift) - 1)) | (penc << LP_SHIFT);
406 	}
407 }
408 
409 /*
410  * Build a VPN_SHIFT bit shifted va given VSID, EA and segment size.
411  */
412 static inline unsigned long hpt_vpn(unsigned long ea,
413 				    unsigned long vsid, int ssize)
414 {
415 	unsigned long mask;
416 	int s_shift = segment_shift(ssize);
417 
418 	mask = (1ul << (s_shift - VPN_SHIFT)) - 1;
419 	return (vsid << (s_shift - VPN_SHIFT)) | ((ea >> VPN_SHIFT) & mask);
420 }
421 
422 /*
423  * This hashes a virtual address
424  */
425 static inline unsigned long hpt_hash(unsigned long vpn,
426 				     unsigned int shift, int ssize)
427 {
428 	unsigned long mask;
429 	unsigned long hash, vsid;
430 
431 	/* VPN_SHIFT can be atmost 12 */
432 	if (ssize == MMU_SEGSIZE_256M) {
433 		mask = (1ul << (SID_SHIFT - VPN_SHIFT)) - 1;
434 		hash = (vpn >> (SID_SHIFT - VPN_SHIFT)) ^
435 			((vpn & mask) >> (shift - VPN_SHIFT));
436 	} else {
437 		mask = (1ul << (SID_SHIFT_1T - VPN_SHIFT)) - 1;
438 		vsid = vpn >> (SID_SHIFT_1T - VPN_SHIFT);
439 		hash = vsid ^ (vsid << 25) ^
440 			((vpn & mask) >> (shift - VPN_SHIFT)) ;
441 	}
442 	return hash & 0x7fffffffffUL;
443 }
444 
445 #define HPTE_LOCAL_UPDATE	0x1
446 #define HPTE_NOHPTE_UPDATE	0x2
447 
448 extern int __hash_page_4K(unsigned long ea, unsigned long access,
449 			  unsigned long vsid, pte_t *ptep, unsigned long trap,
450 			  unsigned long flags, int ssize, int subpage_prot);
451 extern int __hash_page_64K(unsigned long ea, unsigned long access,
452 			   unsigned long vsid, pte_t *ptep, unsigned long trap,
453 			   unsigned long flags, int ssize);
454 struct mm_struct;
455 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap);
456 extern int hash_page_mm(struct mm_struct *mm, unsigned long ea,
457 			unsigned long access, unsigned long trap,
458 			unsigned long flags);
459 extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
460 		     unsigned long dsisr);
461 int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
462 		     pte_t *ptep, unsigned long trap, unsigned long flags,
463 		     int ssize, unsigned int shift, unsigned int mmu_psize);
464 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
465 extern int __hash_page_thp(unsigned long ea, unsigned long access,
466 			   unsigned long vsid, pmd_t *pmdp, unsigned long trap,
467 			   unsigned long flags, int ssize, unsigned int psize);
468 #else
469 static inline int __hash_page_thp(unsigned long ea, unsigned long access,
470 				  unsigned long vsid, pmd_t *pmdp,
471 				  unsigned long trap, unsigned long flags,
472 				  int ssize, unsigned int psize)
473 {
474 	BUG();
475 	return -1;
476 }
477 #endif
478 extern void hash_failure_debug(unsigned long ea, unsigned long access,
479 			       unsigned long vsid, unsigned long trap,
480 			       int ssize, int psize, int lpsize,
481 			       unsigned long pte);
482 extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
483 			     unsigned long pstart, unsigned long prot,
484 			     int psize, int ssize);
485 int htab_remove_mapping(unsigned long vstart, unsigned long vend,
486 			int psize, int ssize);
487 extern void pseries_add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages);
488 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
489 
490 #ifdef CONFIG_PPC_PSERIES
491 void hpte_init_pseries(void);
492 #else
493 static inline void hpte_init_pseries(void) { }
494 #endif
495 
496 extern void hpte_init_native(void);
497 
498 extern void slb_initialize(void);
499 extern void slb_flush_and_rebolt(void);
500 void slb_flush_all_realmode(void);
501 void __slb_restore_bolted_realmode(void);
502 void slb_restore_bolted_realmode(void);
503 
504 extern void slb_vmalloc_update(void);
505 extern void slb_set_size(u16 size);
506 #endif /* __ASSEMBLY__ */
507 
508 /*
509  * VSID allocation (256MB segment)
510  *
511  * We first generate a 37-bit "proto-VSID". Proto-VSIDs are generated
512  * from mmu context id and effective segment id of the address.
513  *
514  * For user processes max context id is limited to MAX_USER_CONTEXT.
515 
516  * For kernel space, we use context ids 1-4 to map addresses as below:
517  * NOTE: each context only support 64TB now.
518  * 0x00001 -  [ 0xc000000000000000 - 0xc0003fffffffffff ]
519  * 0x00002 -  [ 0xd000000000000000 - 0xd0003fffffffffff ]
520  * 0x00003 -  [ 0xe000000000000000 - 0xe0003fffffffffff ]
521  * 0x00004 -  [ 0xf000000000000000 - 0xf0003fffffffffff ]
522  *
523  * The proto-VSIDs are then scrambled into real VSIDs with the
524  * multiplicative hash:
525  *
526  *	VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
527  *
528  * VSID_MULTIPLIER is prime, so in particular it is
529  * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
530  * Because the modulus is 2^n-1 we can compute it efficiently without
531  * a divide or extra multiply (see below). The scramble function gives
532  * robust scattering in the hash table (at least based on some initial
533  * results).
534  *
535  * We use VSID 0 to indicate an invalid VSID. The means we can't use context id
536  * 0, because a context id of 0 and an EA of 0 gives a proto-VSID of 0, which
537  * will produce a VSID of 0.
538  *
539  * We also need to avoid the last segment of the last context, because that
540  * would give a protovsid of 0x1fffffffff. That will result in a VSID 0
541  * because of the modulo operation in vsid scramble.
542  */
543 
544 /*
545  * Max Va bits we support as of now is 68 bits. We want 19 bit
546  * context ID.
547  * Restrictions:
548  * GPU has restrictions of not able to access beyond 128TB
549  * (47 bit effective address). We also cannot do more than 20bit PID.
550  * For p4 and p5 which can only do 65 bit VA, we restrict our CONTEXT_BITS
551  * to 16 bits (ie, we can only have 2^16 pids at the same time).
552  */
553 #define VA_BITS			68
554 #define CONTEXT_BITS		19
555 #define ESID_BITS		(VA_BITS - (SID_SHIFT + CONTEXT_BITS))
556 #define ESID_BITS_1T		(VA_BITS - (SID_SHIFT_1T + CONTEXT_BITS))
557 
558 #define ESID_BITS_MASK		((1 << ESID_BITS) - 1)
559 #define ESID_BITS_1T_MASK	((1 << ESID_BITS_1T) - 1)
560 
561 /*
562  * 256MB segment
563  * The proto-VSID space has 2^(CONTEX_BITS + ESID_BITS) - 1 segments
564  * available for user + kernel mapping. VSID 0 is reserved as invalid, contexts
565  * 1-4 are used for kernel mapping. Each segment contains 2^28 bytes. Each
566  * context maps 2^49 bytes (512TB).
567  *
568  * We also need to avoid the last segment of the last context, because that
569  * would give a protovsid of 0x1fffffffff. That will result in a VSID 0
570  * because of the modulo operation in vsid scramble.
571  */
572 #define MAX_USER_CONTEXT	((ASM_CONST(1) << CONTEXT_BITS) - 2)
573 #define MIN_USER_CONTEXT	(5)
574 
575 /* Would be nice to use KERNEL_REGION_ID here */
576 #define KERNEL_REGION_CONTEXT_OFFSET	(0xc - 1)
577 
578 /*
579  * For platforms that support on 65bit VA we limit the context bits
580  */
581 #define MAX_USER_CONTEXT_65BIT_VA ((ASM_CONST(1) << (65 - (SID_SHIFT + ESID_BITS))) - 2)
582 
583 /*
584  * This should be computed such that protovosid * vsid_mulitplier
585  * doesn't overflow 64 bits. The vsid_mutliplier should also be
586  * co-prime to vsid_modulus. We also need to make sure that number
587  * of bits in multiplied result (dividend) is less than twice the number of
588  * protovsid bits for our modulus optmization to work.
589  *
590  * The below table shows the current values used.
591  * |-------+------------+----------------------+------------+-------------------|
592  * |       | Prime Bits | proto VSID_BITS_65VA | Total Bits | 2* prot VSID_BITS |
593  * |-------+------------+----------------------+------------+-------------------|
594  * | 1T    |         24 |                   25 |         49 |                50 |
595  * |-------+------------+----------------------+------------+-------------------|
596  * | 256MB |         24 |                   37 |         61 |                74 |
597  * |-------+------------+----------------------+------------+-------------------|
598  *
599  * |-------+------------+----------------------+------------+--------------------|
600  * |       | Prime Bits | proto VSID_BITS_68VA | Total Bits | 2* proto VSID_BITS |
601  * |-------+------------+----------------------+------------+--------------------|
602  * | 1T    |         24 |                   28 |         52 |                 56 |
603  * |-------+------------+----------------------+------------+--------------------|
604  * | 256MB |         24 |                   40 |         64 |                 80 |
605  * |-------+------------+----------------------+------------+--------------------|
606  *
607  */
608 #define VSID_MULTIPLIER_256M	ASM_CONST(12538073)	/* 24-bit prime */
609 #define VSID_BITS_256M		(VA_BITS - SID_SHIFT)
610 #define VSID_BITS_65_256M	(65 - SID_SHIFT)
611 /*
612  * Modular multiplicative inverse of VSID_MULTIPLIER under modulo VSID_MODULUS
613  */
614 #define VSID_MULINV_256M	ASM_CONST(665548017062)
615 
616 #define VSID_MULTIPLIER_1T	ASM_CONST(12538073)	/* 24-bit prime */
617 #define VSID_BITS_1T		(VA_BITS - SID_SHIFT_1T)
618 #define VSID_BITS_65_1T		(65 - SID_SHIFT_1T)
619 #define VSID_MULINV_1T		ASM_CONST(209034062)
620 
621 /* 1TB VSID reserved for VRMA */
622 #define VRMA_VSID	0x1ffffffUL
623 #define USER_VSID_RANGE	(1UL << (ESID_BITS + SID_SHIFT))
624 
625 /* 4 bits per slice and we have one slice per 1TB */
626 #define SLICE_ARRAY_SIZE	(H_PGTABLE_RANGE >> 41)
627 #define TASK_SLICE_ARRAY_SZ(x)	((x)->context.slb_addr_limit >> 41)
628 
629 #ifndef __ASSEMBLY__
630 
631 #ifdef CONFIG_PPC_SUBPAGE_PROT
632 /*
633  * For the sub-page protection option, we extend the PGD with one of
634  * these.  Basically we have a 3-level tree, with the top level being
635  * the protptrs array.  To optimize speed and memory consumption when
636  * only addresses < 4GB are being protected, pointers to the first
637  * four pages of sub-page protection words are stored in the low_prot
638  * array.
639  * Each page of sub-page protection words protects 1GB (4 bytes
640  * protects 64k).  For the 3-level tree, each page of pointers then
641  * protects 8TB.
642  */
643 struct subpage_prot_table {
644 	unsigned long maxaddr;	/* only addresses < this are protected */
645 	unsigned int **protptrs[(TASK_SIZE_USER64 >> 43)];
646 	unsigned int *low_prot[4];
647 };
648 
649 #define SBP_L1_BITS		(PAGE_SHIFT - 2)
650 #define SBP_L2_BITS		(PAGE_SHIFT - 3)
651 #define SBP_L1_COUNT		(1 << SBP_L1_BITS)
652 #define SBP_L2_COUNT		(1 << SBP_L2_BITS)
653 #define SBP_L2_SHIFT		(PAGE_SHIFT + SBP_L1_BITS)
654 #define SBP_L3_SHIFT		(SBP_L2_SHIFT + SBP_L2_BITS)
655 
656 extern void subpage_prot_free(struct mm_struct *mm);
657 extern void subpage_prot_init_new_context(struct mm_struct *mm);
658 #else
659 static inline void subpage_prot_free(struct mm_struct *mm) {}
660 static inline void subpage_prot_init_new_context(struct mm_struct *mm) { }
661 #endif /* CONFIG_PPC_SUBPAGE_PROT */
662 
663 #if 0
664 /*
665  * The code below is equivalent to this function for arguments
666  * < 2^VSID_BITS, which is all this should ever be called
667  * with.  However gcc is not clever enough to compute the
668  * modulus (2^n-1) without a second multiply.
669  */
670 #define vsid_scramble(protovsid, size) \
671 	((((protovsid) * VSID_MULTIPLIER_##size) % VSID_MODULUS_##size))
672 
673 /* simplified form avoiding mod operation */
674 #define vsid_scramble(protovsid, size) \
675 	({								 \
676 		unsigned long x;					 \
677 		x = (protovsid) * VSID_MULTIPLIER_##size;		 \
678 		x = (x >> VSID_BITS_##size) + (x & VSID_MODULUS_##size); \
679 		(x + ((x+1) >> VSID_BITS_##size)) & VSID_MODULUS_##size; \
680 	})
681 
682 #else /* 1 */
683 static inline unsigned long vsid_scramble(unsigned long protovsid,
684 				  unsigned long vsid_multiplier, int vsid_bits)
685 {
686 	unsigned long vsid;
687 	unsigned long vsid_modulus = ((1UL << vsid_bits) - 1);
688 	/*
689 	 * We have same multipler for both 256 and 1T segements now
690 	 */
691 	vsid = protovsid * vsid_multiplier;
692 	vsid = (vsid >> vsid_bits) + (vsid & vsid_modulus);
693 	return (vsid + ((vsid + 1) >> vsid_bits)) & vsid_modulus;
694 }
695 
696 #endif /* 1 */
697 
698 /* Returns the segment size indicator for a user address */
699 static inline int user_segment_size(unsigned long addr)
700 {
701 	/* Use 1T segments if possible for addresses >= 1T */
702 	if (addr >= (1UL << SID_SHIFT_1T))
703 		return mmu_highuser_ssize;
704 	return MMU_SEGSIZE_256M;
705 }
706 
707 static inline unsigned long get_vsid(unsigned long context, unsigned long ea,
708 				     int ssize)
709 {
710 	unsigned long va_bits = VA_BITS;
711 	unsigned long vsid_bits;
712 	unsigned long protovsid;
713 
714 	/*
715 	 * Bad address. We return VSID 0 for that
716 	 */
717 	if ((ea & ~REGION_MASK) >= H_PGTABLE_RANGE)
718 		return 0;
719 
720 	if (!mmu_has_feature(MMU_FTR_68_BIT_VA))
721 		va_bits = 65;
722 
723 	if (ssize == MMU_SEGSIZE_256M) {
724 		vsid_bits = va_bits - SID_SHIFT;
725 		protovsid = (context << ESID_BITS) |
726 			((ea >> SID_SHIFT) & ESID_BITS_MASK);
727 		return vsid_scramble(protovsid, VSID_MULTIPLIER_256M, vsid_bits);
728 	}
729 	/* 1T segment */
730 	vsid_bits = va_bits - SID_SHIFT_1T;
731 	protovsid = (context << ESID_BITS_1T) |
732 		((ea >> SID_SHIFT_1T) & ESID_BITS_1T_MASK);
733 	return vsid_scramble(protovsid, VSID_MULTIPLIER_1T, vsid_bits);
734 }
735 
736 /*
737  * This is only valid for addresses >= PAGE_OFFSET
738  */
739 static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
740 {
741 	unsigned long context;
742 
743 	if (!is_kernel_addr(ea))
744 		return 0;
745 
746 	/*
747 	 * For kernel space, we use context ids 1-4 to map the address space as
748 	 * below:
749 	 *
750 	 * 0x00001 -  [ 0xc000000000000000 - 0xc0003fffffffffff ]
751 	 * 0x00002 -  [ 0xd000000000000000 - 0xd0003fffffffffff ]
752 	 * 0x00003 -  [ 0xe000000000000000 - 0xe0003fffffffffff ]
753 	 * 0x00004 -  [ 0xf000000000000000 - 0xf0003fffffffffff ]
754 	 *
755 	 * So we can compute the context from the region (top nibble) by
756 	 * subtracting 11, or 0xc - 1.
757 	 */
758 	context = (ea >> 60) - KERNEL_REGION_CONTEXT_OFFSET;
759 
760 	return get_vsid(context, ea, ssize);
761 }
762 
763 unsigned htab_shift_for_mem_size(unsigned long mem_size);
764 
765 #endif /* __ASSEMBLY__ */
766 
767 #endif /* _ASM_POWERPC_BOOK3S_64_MMU_HASH_H_ */
768