1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef _ASM_POWERPC_BOOK3S_64_MMU_HASH_H_
3 #define _ASM_POWERPC_BOOK3S_64_MMU_HASH_H_
4 /*
5 * PowerPC64 memory management structures
6 *
7 * Dave Engebretsen & Mike Corrigan <{engebret|mikejc}@us.ibm.com>
8 * PPC64 rework.
9 */
10
11 #include <asm/page.h>
12 #include <asm/bug.h>
13 #include <asm/asm-const.h>
14
15 /*
16 * This is necessary to get the definition of PGTABLE_RANGE which we
17 * need for various slices related matters. Note that this isn't the
18 * complete pgtable.h but only a portion of it.
19 */
20 #include <asm/book3s/64/pgtable.h>
21 #include <asm/bug.h>
22 #include <asm/task_size_64.h>
23 #include <asm/cpu_has_feature.h>
24
25 /*
26 * SLB
27 */
28
29 #define SLB_NUM_BOLTED 2
30 #define SLB_CACHE_ENTRIES 8
31 #define SLB_MIN_SIZE 32
32
33 /* Bits in the SLB ESID word */
34 #define SLB_ESID_V ASM_CONST(0x0000000008000000) /* valid */
35
36 /* Bits in the SLB VSID word */
37 #define SLB_VSID_SHIFT 12
38 #define SLB_VSID_SHIFT_256M SLB_VSID_SHIFT
39 #define SLB_VSID_SHIFT_1T 24
40 #define SLB_VSID_SSIZE_SHIFT 62
41 #define SLB_VSID_B ASM_CONST(0xc000000000000000)
42 #define SLB_VSID_B_256M ASM_CONST(0x0000000000000000)
43 #define SLB_VSID_B_1T ASM_CONST(0x4000000000000000)
44 #define SLB_VSID_KS ASM_CONST(0x0000000000000800)
45 #define SLB_VSID_KP ASM_CONST(0x0000000000000400)
46 #define SLB_VSID_N ASM_CONST(0x0000000000000200) /* no-execute */
47 #define SLB_VSID_L ASM_CONST(0x0000000000000100)
48 #define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */
49 #define SLB_VSID_LP ASM_CONST(0x0000000000000030)
50 #define SLB_VSID_LP_00 ASM_CONST(0x0000000000000000)
51 #define SLB_VSID_LP_01 ASM_CONST(0x0000000000000010)
52 #define SLB_VSID_LP_10 ASM_CONST(0x0000000000000020)
53 #define SLB_VSID_LP_11 ASM_CONST(0x0000000000000030)
54 #define SLB_VSID_LLP (SLB_VSID_L|SLB_VSID_LP)
55
56 #define SLB_VSID_KERNEL (SLB_VSID_KP)
57 #define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS|SLB_VSID_C)
58
59 #define SLBIE_C (0x08000000)
60 #define SLBIE_SSIZE_SHIFT 25
61
62 /*
63 * Hash table
64 */
65
66 #define HPTES_PER_GROUP 8
67
68 #define HPTE_V_SSIZE_SHIFT 62
69 #define HPTE_V_AVPN_SHIFT 7
70 #define HPTE_V_COMMON_BITS ASM_CONST(0x000fffffffffffff)
71 #define HPTE_V_AVPN ASM_CONST(0x3fffffffffffff80)
72 #define HPTE_V_AVPN_3_0 ASM_CONST(0x000fffffffffff80)
73 #define HPTE_V_AVPN_VAL(x) (((x) & HPTE_V_AVPN) >> HPTE_V_AVPN_SHIFT)
74 #define HPTE_V_COMPARE(x,y) (!(((x) ^ (y)) & 0xffffffffffffff80UL))
75 #define HPTE_V_BOLTED ASM_CONST(0x0000000000000010)
76 #define HPTE_V_LOCK ASM_CONST(0x0000000000000008)
77 #define HPTE_V_LARGE ASM_CONST(0x0000000000000004)
78 #define HPTE_V_SECONDARY ASM_CONST(0x0000000000000002)
79 #define HPTE_V_VALID ASM_CONST(0x0000000000000001)
80
81 /*
82 * ISA 3.0 has a different HPTE format.
83 */
84 #define HPTE_R_3_0_SSIZE_SHIFT 58
85 #define HPTE_R_3_0_SSIZE_MASK (3ull << HPTE_R_3_0_SSIZE_SHIFT)
86 #define HPTE_R_PP0 ASM_CONST(0x8000000000000000)
87 #define HPTE_R_TS ASM_CONST(0x4000000000000000)
88 #define HPTE_R_KEY_HI ASM_CONST(0x3000000000000000)
89 #define HPTE_R_KEY_BIT4 ASM_CONST(0x2000000000000000)
90 #define HPTE_R_KEY_BIT3 ASM_CONST(0x1000000000000000)
91 #define HPTE_R_RPN_SHIFT 12
92 #define HPTE_R_RPN ASM_CONST(0x0ffffffffffff000)
93 #define HPTE_R_RPN_3_0 ASM_CONST(0x01fffffffffff000)
94 #define HPTE_R_PP ASM_CONST(0x0000000000000003)
95 #define HPTE_R_PPP ASM_CONST(0x8000000000000003)
96 #define HPTE_R_N ASM_CONST(0x0000000000000004)
97 #define HPTE_R_G ASM_CONST(0x0000000000000008)
98 #define HPTE_R_M ASM_CONST(0x0000000000000010)
99 #define HPTE_R_I ASM_CONST(0x0000000000000020)
100 #define HPTE_R_W ASM_CONST(0x0000000000000040)
101 #define HPTE_R_WIMG ASM_CONST(0x0000000000000078)
102 #define HPTE_R_C ASM_CONST(0x0000000000000080)
103 #define HPTE_R_R ASM_CONST(0x0000000000000100)
104 #define HPTE_R_KEY_LO ASM_CONST(0x0000000000000e00)
105 #define HPTE_R_KEY_BIT2 ASM_CONST(0x0000000000000800)
106 #define HPTE_R_KEY_BIT1 ASM_CONST(0x0000000000000400)
107 #define HPTE_R_KEY_BIT0 ASM_CONST(0x0000000000000200)
108 #define HPTE_R_KEY (HPTE_R_KEY_LO | HPTE_R_KEY_HI)
109
110 #define HPTE_V_1TB_SEG ASM_CONST(0x4000000000000000)
111 #define HPTE_V_VRMA_MASK ASM_CONST(0x4001ffffff000000)
112
113 /* Values for PP (assumes Ks=0, Kp=1) */
114 #define PP_RWXX 0 /* Supervisor read/write, User none */
115 #define PP_RWRX 1 /* Supervisor read/write, User read */
116 #define PP_RWRW 2 /* Supervisor read/write, User read/write */
117 #define PP_RXRX 3 /* Supervisor read, User read */
118 #define PP_RXXX (HPTE_R_PP0 | 2) /* Supervisor read, user none */
119
120 /* Fields for tlbiel instruction in architecture 2.06 */
121 #define TLBIEL_INVAL_SEL_MASK 0xc00 /* invalidation selector */
122 #define TLBIEL_INVAL_PAGE 0x000 /* invalidate a single page */
123 #define TLBIEL_INVAL_SET_LPID 0x800 /* invalidate a set for current LPID */
124 #define TLBIEL_INVAL_SET 0xc00 /* invalidate a set for all LPIDs */
125 #define TLBIEL_INVAL_SET_MASK 0xfff000 /* set number to inval. */
126 #define TLBIEL_INVAL_SET_SHIFT 12
127
128 #define POWER7_TLB_SETS 128 /* # sets in POWER7 TLB */
129 #define POWER8_TLB_SETS 512 /* # sets in POWER8 TLB */
130 #define POWER9_TLB_SETS_HASH 256 /* # sets in POWER9 TLB Hash mode */
131 #define POWER9_TLB_SETS_RADIX 128 /* # sets in POWER9 TLB Radix mode */
132
133 #ifndef __ASSEMBLY__
134
135 struct mmu_hash_ops {
136 void (*hpte_invalidate)(unsigned long slot,
137 unsigned long vpn,
138 int bpsize, int apsize,
139 int ssize, int local);
140 long (*hpte_updatepp)(unsigned long slot,
141 unsigned long newpp,
142 unsigned long vpn,
143 int bpsize, int apsize,
144 int ssize, unsigned long flags);
145 void (*hpte_updateboltedpp)(unsigned long newpp,
146 unsigned long ea,
147 int psize, int ssize);
148 long (*hpte_insert)(unsigned long hpte_group,
149 unsigned long vpn,
150 unsigned long prpn,
151 unsigned long rflags,
152 unsigned long vflags,
153 int psize, int apsize,
154 int ssize);
155 long (*hpte_remove)(unsigned long hpte_group);
156 int (*hpte_removebolted)(unsigned long ea,
157 int psize, int ssize);
158 void (*flush_hash_range)(unsigned long number, int local);
159 void (*hugepage_invalidate)(unsigned long vsid,
160 unsigned long addr,
161 unsigned char *hpte_slot_array,
162 int psize, int ssize, int local);
163 int (*resize_hpt)(unsigned long shift);
164 /*
165 * Special for kexec.
166 * To be called in real mode with interrupts disabled. No locks are
167 * taken as such, concurrent access on pre POWER5 hardware could result
168 * in a deadlock.
169 * The linear mapping is destroyed as well.
170 */
171 void (*hpte_clear_all)(void);
172 };
173 extern struct mmu_hash_ops mmu_hash_ops;
174
175 struct hash_pte {
176 __be64 v;
177 __be64 r;
178 };
179
180 extern struct hash_pte *htab_address;
181 extern unsigned long htab_size_bytes;
182 extern unsigned long htab_hash_mask;
183
184
shift_to_mmu_psize(unsigned int shift)185 static inline int shift_to_mmu_psize(unsigned int shift)
186 {
187 int psize;
188
189 for (psize = 0; psize < MMU_PAGE_COUNT; ++psize)
190 if (mmu_psize_defs[psize].shift == shift)
191 return psize;
192 return -1;
193 }
194
mmu_psize_to_shift(unsigned int mmu_psize)195 static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
196 {
197 if (mmu_psize_defs[mmu_psize].shift)
198 return mmu_psize_defs[mmu_psize].shift;
199 BUG();
200 }
201
ap_to_shift(unsigned long ap)202 static inline unsigned int ap_to_shift(unsigned long ap)
203 {
204 int psize;
205
206 for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
207 if (mmu_psize_defs[psize].ap == ap)
208 return mmu_psize_defs[psize].shift;
209 }
210
211 return -1;
212 }
213
get_sllp_encoding(int psize)214 static inline unsigned long get_sllp_encoding(int psize)
215 {
216 unsigned long sllp;
217
218 sllp = ((mmu_psize_defs[psize].sllp & SLB_VSID_L) >> 6) |
219 ((mmu_psize_defs[psize].sllp & SLB_VSID_LP) >> 4);
220 return sllp;
221 }
222
223 #endif /* __ASSEMBLY__ */
224
225 /*
226 * Segment sizes.
227 * These are the values used by hardware in the B field of
228 * SLB entries and the first dword of MMU hashtable entries.
229 * The B field is 2 bits; the values 2 and 3 are unused and reserved.
230 */
231 #define MMU_SEGSIZE_256M 0
232 #define MMU_SEGSIZE_1T 1
233
234 /*
235 * encode page number shift.
236 * in order to fit the 78 bit va in a 64 bit variable we shift the va by
237 * 12 bits. This enable us to address upto 76 bit va.
238 * For hpt hash from a va we can ignore the page size bits of va and for
239 * hpte encoding we ignore up to 23 bits of va. So ignoring lower 12 bits ensure
240 * we work in all cases including 4k page size.
241 */
242 #define VPN_SHIFT 12
243
244 /*
245 * HPTE Large Page (LP) details
246 */
247 #define LP_SHIFT 12
248 #define LP_BITS 8
249 #define LP_MASK(i) ((0xFF >> (i)) << LP_SHIFT)
250
251 #ifndef __ASSEMBLY__
252
slb_vsid_shift(int ssize)253 static inline int slb_vsid_shift(int ssize)
254 {
255 if (ssize == MMU_SEGSIZE_256M)
256 return SLB_VSID_SHIFT;
257 return SLB_VSID_SHIFT_1T;
258 }
259
segment_shift(int ssize)260 static inline int segment_shift(int ssize)
261 {
262 if (ssize == MMU_SEGSIZE_256M)
263 return SID_SHIFT;
264 return SID_SHIFT_1T;
265 }
266
267 /*
268 * This array is indexed by the LP field of the HPTE second dword.
269 * Since this field may contain some RPN bits, some entries are
270 * replicated so that we get the same value irrespective of RPN.
271 * The top 4 bits are the page size index (MMU_PAGE_*) for the
272 * actual page size, the bottom 4 bits are the base page size.
273 */
274 extern u8 hpte_page_sizes[1 << LP_BITS];
275
__hpte_page_size(unsigned long h,unsigned long l,bool is_base_size)276 static inline unsigned long __hpte_page_size(unsigned long h, unsigned long l,
277 bool is_base_size)
278 {
279 unsigned int i, lp;
280
281 if (!(h & HPTE_V_LARGE))
282 return 1ul << 12;
283
284 /* Look at the 8 bit LP value */
285 lp = (l >> LP_SHIFT) & ((1 << LP_BITS) - 1);
286 i = hpte_page_sizes[lp];
287 if (!i)
288 return 0;
289 if (!is_base_size)
290 i >>= 4;
291 return 1ul << mmu_psize_defs[i & 0xf].shift;
292 }
293
hpte_page_size(unsigned long h,unsigned long l)294 static inline unsigned long hpte_page_size(unsigned long h, unsigned long l)
295 {
296 return __hpte_page_size(h, l, 0);
297 }
298
hpte_base_page_size(unsigned long h,unsigned long l)299 static inline unsigned long hpte_base_page_size(unsigned long h, unsigned long l)
300 {
301 return __hpte_page_size(h, l, 1);
302 }
303
304 /*
305 * The current system page and segment sizes
306 */
307 extern int mmu_kernel_ssize;
308 extern int mmu_highuser_ssize;
309 extern u16 mmu_slb_size;
310 extern unsigned long tce_alloc_start, tce_alloc_end;
311
312 /*
313 * If the processor supports 64k normal pages but not 64k cache
314 * inhibited pages, we have to be prepared to switch processes
315 * to use 4k pages when they create cache-inhibited mappings.
316 * If this is the case, mmu_ci_restrictions will be set to 1.
317 */
318 extern int mmu_ci_restrictions;
319
320 /*
321 * This computes the AVPN and B fields of the first dword of a HPTE,
322 * for use when we want to match an existing PTE. The bottom 7 bits
323 * of the returned value are zero.
324 */
hpte_encode_avpn(unsigned long vpn,int psize,int ssize)325 static inline unsigned long hpte_encode_avpn(unsigned long vpn, int psize,
326 int ssize)
327 {
328 unsigned long v;
329 /*
330 * The AVA field omits the low-order 23 bits of the 78 bits VA.
331 * These bits are not needed in the PTE, because the
332 * low-order b of these bits are part of the byte offset
333 * into the virtual page and, if b < 23, the high-order
334 * 23-b of these bits are always used in selecting the
335 * PTEGs to be searched
336 */
337 v = (vpn >> (23 - VPN_SHIFT)) & ~(mmu_psize_defs[psize].avpnm);
338 v <<= HPTE_V_AVPN_SHIFT;
339 v |= ((unsigned long) ssize) << HPTE_V_SSIZE_SHIFT;
340 return v;
341 }
342
343 /*
344 * ISA v3.0 defines a new HPTE format, which differs from the old
345 * format in having smaller AVPN and ARPN fields, and the B field
346 * in the second dword instead of the first.
347 */
hpte_old_to_new_v(unsigned long v)348 static inline unsigned long hpte_old_to_new_v(unsigned long v)
349 {
350 /* trim AVPN, drop B */
351 return v & HPTE_V_COMMON_BITS;
352 }
353
hpte_old_to_new_r(unsigned long v,unsigned long r)354 static inline unsigned long hpte_old_to_new_r(unsigned long v, unsigned long r)
355 {
356 /* move B field from 1st to 2nd dword, trim ARPN */
357 return (r & ~HPTE_R_3_0_SSIZE_MASK) |
358 (((v) >> HPTE_V_SSIZE_SHIFT) << HPTE_R_3_0_SSIZE_SHIFT);
359 }
360
hpte_new_to_old_v(unsigned long v,unsigned long r)361 static inline unsigned long hpte_new_to_old_v(unsigned long v, unsigned long r)
362 {
363 /* insert B field */
364 return (v & HPTE_V_COMMON_BITS) |
365 ((r & HPTE_R_3_0_SSIZE_MASK) <<
366 (HPTE_V_SSIZE_SHIFT - HPTE_R_3_0_SSIZE_SHIFT));
367 }
368
hpte_new_to_old_r(unsigned long r)369 static inline unsigned long hpte_new_to_old_r(unsigned long r)
370 {
371 /* clear out B field */
372 return r & ~HPTE_R_3_0_SSIZE_MASK;
373 }
374
hpte_get_old_v(struct hash_pte * hptep)375 static inline unsigned long hpte_get_old_v(struct hash_pte *hptep)
376 {
377 unsigned long hpte_v;
378
379 hpte_v = be64_to_cpu(hptep->v);
380 if (cpu_has_feature(CPU_FTR_ARCH_300))
381 hpte_v = hpte_new_to_old_v(hpte_v, be64_to_cpu(hptep->r));
382 return hpte_v;
383 }
384
385 /*
386 * This function sets the AVPN and L fields of the HPTE appropriately
387 * using the base page size and actual page size.
388 */
hpte_encode_v(unsigned long vpn,int base_psize,int actual_psize,int ssize)389 static inline unsigned long hpte_encode_v(unsigned long vpn, int base_psize,
390 int actual_psize, int ssize)
391 {
392 unsigned long v;
393 v = hpte_encode_avpn(vpn, base_psize, ssize);
394 if (actual_psize != MMU_PAGE_4K)
395 v |= HPTE_V_LARGE;
396 return v;
397 }
398
399 /*
400 * This function sets the ARPN, and LP fields of the HPTE appropriately
401 * for the page size. We assume the pa is already "clean" that is properly
402 * aligned for the requested page size
403 */
hpte_encode_r(unsigned long pa,int base_psize,int actual_psize)404 static inline unsigned long hpte_encode_r(unsigned long pa, int base_psize,
405 int actual_psize)
406 {
407 /* A 4K page needs no special encoding */
408 if (actual_psize == MMU_PAGE_4K)
409 return pa & HPTE_R_RPN;
410 else {
411 unsigned int penc = mmu_psize_defs[base_psize].penc[actual_psize];
412 unsigned int shift = mmu_psize_defs[actual_psize].shift;
413 return (pa & ~((1ul << shift) - 1)) | (penc << LP_SHIFT);
414 }
415 }
416
417 /*
418 * Build a VPN_SHIFT bit shifted va given VSID, EA and segment size.
419 */
hpt_vpn(unsigned long ea,unsigned long vsid,int ssize)420 static inline unsigned long hpt_vpn(unsigned long ea,
421 unsigned long vsid, int ssize)
422 {
423 unsigned long mask;
424 int s_shift = segment_shift(ssize);
425
426 mask = (1ul << (s_shift - VPN_SHIFT)) - 1;
427 return (vsid << (s_shift - VPN_SHIFT)) | ((ea >> VPN_SHIFT) & mask);
428 }
429
430 /*
431 * This hashes a virtual address
432 */
hpt_hash(unsigned long vpn,unsigned int shift,int ssize)433 static inline unsigned long hpt_hash(unsigned long vpn,
434 unsigned int shift, int ssize)
435 {
436 unsigned long mask;
437 unsigned long hash, vsid;
438
439 /* VPN_SHIFT can be atmost 12 */
440 if (ssize == MMU_SEGSIZE_256M) {
441 mask = (1ul << (SID_SHIFT - VPN_SHIFT)) - 1;
442 hash = (vpn >> (SID_SHIFT - VPN_SHIFT)) ^
443 ((vpn & mask) >> (shift - VPN_SHIFT));
444 } else {
445 mask = (1ul << (SID_SHIFT_1T - VPN_SHIFT)) - 1;
446 vsid = vpn >> (SID_SHIFT_1T - VPN_SHIFT);
447 hash = vsid ^ (vsid << 25) ^
448 ((vpn & mask) >> (shift - VPN_SHIFT)) ;
449 }
450 return hash & 0x7fffffffffUL;
451 }
452
453 #define HPTE_LOCAL_UPDATE 0x1
454 #define HPTE_NOHPTE_UPDATE 0x2
455
456 extern int __hash_page_4K(unsigned long ea, unsigned long access,
457 unsigned long vsid, pte_t *ptep, unsigned long trap,
458 unsigned long flags, int ssize, int subpage_prot);
459 extern int __hash_page_64K(unsigned long ea, unsigned long access,
460 unsigned long vsid, pte_t *ptep, unsigned long trap,
461 unsigned long flags, int ssize);
462 struct mm_struct;
463 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap);
464 extern int hash_page_mm(struct mm_struct *mm, unsigned long ea,
465 unsigned long access, unsigned long trap,
466 unsigned long flags);
467 extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
468 unsigned long dsisr);
469 int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
470 pte_t *ptep, unsigned long trap, unsigned long flags,
471 int ssize, unsigned int shift, unsigned int mmu_psize);
472 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
473 extern int __hash_page_thp(unsigned long ea, unsigned long access,
474 unsigned long vsid, pmd_t *pmdp, unsigned long trap,
475 unsigned long flags, int ssize, unsigned int psize);
476 #else
__hash_page_thp(unsigned long ea,unsigned long access,unsigned long vsid,pmd_t * pmdp,unsigned long trap,unsigned long flags,int ssize,unsigned int psize)477 static inline int __hash_page_thp(unsigned long ea, unsigned long access,
478 unsigned long vsid, pmd_t *pmdp,
479 unsigned long trap, unsigned long flags,
480 int ssize, unsigned int psize)
481 {
482 BUG();
483 return -1;
484 }
485 #endif
486 extern void hash_failure_debug(unsigned long ea, unsigned long access,
487 unsigned long vsid, unsigned long trap,
488 int ssize, int psize, int lpsize,
489 unsigned long pte);
490 extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
491 unsigned long pstart, unsigned long prot,
492 int psize, int ssize);
493 int htab_remove_mapping(unsigned long vstart, unsigned long vend,
494 int psize, int ssize);
495 extern void pseries_add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages);
496 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
497
498 extern void hash__setup_new_exec(void);
499
500 #ifdef CONFIG_PPC_PSERIES
501 void hpte_init_pseries(void);
502 #else
hpte_init_pseries(void)503 static inline void hpte_init_pseries(void) { }
504 #endif
505
506 extern void hpte_init_native(void);
507
508 struct slb_entry {
509 u64 esid;
510 u64 vsid;
511 };
512
513 extern void slb_initialize(void);
514 void slb_flush_and_restore_bolted(void);
515 void slb_flush_all_realmode(void);
516 void __slb_restore_bolted_realmode(void);
517 void slb_restore_bolted_realmode(void);
518 void slb_save_contents(struct slb_entry *slb_ptr);
519 void slb_dump_contents(struct slb_entry *slb_ptr);
520
521 extern void slb_vmalloc_update(void);
522 extern void slb_set_size(u16 size);
523 #endif /* __ASSEMBLY__ */
524
525 /*
526 * VSID allocation (256MB segment)
527 *
528 * We first generate a 37-bit "proto-VSID". Proto-VSIDs are generated
529 * from mmu context id and effective segment id of the address.
530 *
531 * For user processes max context id is limited to MAX_USER_CONTEXT.
532 * more details in get_user_context
533 *
534 * For kernel space get_kernel_context
535 *
536 * The proto-VSIDs are then scrambled into real VSIDs with the
537 * multiplicative hash:
538 *
539 * VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
540 *
541 * VSID_MULTIPLIER is prime, so in particular it is
542 * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
543 * Because the modulus is 2^n-1 we can compute it efficiently without
544 * a divide or extra multiply (see below). The scramble function gives
545 * robust scattering in the hash table (at least based on some initial
546 * results).
547 *
548 * We use VSID 0 to indicate an invalid VSID. The means we can't use context id
549 * 0, because a context id of 0 and an EA of 0 gives a proto-VSID of 0, which
550 * will produce a VSID of 0.
551 *
552 * We also need to avoid the last segment of the last context, because that
553 * would give a protovsid of 0x1fffffffff. That will result in a VSID 0
554 * because of the modulo operation in vsid scramble.
555 */
556
557 /*
558 * Max Va bits we support as of now is 68 bits. We want 19 bit
559 * context ID.
560 * Restrictions:
561 * GPU has restrictions of not able to access beyond 128TB
562 * (47 bit effective address). We also cannot do more than 20bit PID.
563 * For p4 and p5 which can only do 65 bit VA, we restrict our CONTEXT_BITS
564 * to 16 bits (ie, we can only have 2^16 pids at the same time).
565 */
566 #define VA_BITS 68
567 #define CONTEXT_BITS 19
568 #define ESID_BITS (VA_BITS - (SID_SHIFT + CONTEXT_BITS))
569 #define ESID_BITS_1T (VA_BITS - (SID_SHIFT_1T + CONTEXT_BITS))
570
571 #define ESID_BITS_MASK ((1 << ESID_BITS) - 1)
572 #define ESID_BITS_1T_MASK ((1 << ESID_BITS_1T) - 1)
573
574 /*
575 * Now certain config support MAX_PHYSMEM more than 512TB. Hence we will need
576 * to use more than one context for linear mapping the kernel.
577 * For vmalloc and memmap, we use just one context with 512TB. With 64 byte
578 * struct page size, we need ony 32 TB in memmap for 2PB (51 bits (MAX_PHYSMEM_BITS)).
579 */
580 #if (H_MAX_PHYSMEM_BITS > MAX_EA_BITS_PER_CONTEXT)
581 #define MAX_KERNEL_CTX_CNT (1UL << (H_MAX_PHYSMEM_BITS - MAX_EA_BITS_PER_CONTEXT))
582 #else
583 #define MAX_KERNEL_CTX_CNT 1
584 #endif
585
586 #define MAX_VMALLOC_CTX_CNT 1
587 #define MAX_IO_CTX_CNT 1
588 #define MAX_VMEMMAP_CTX_CNT 1
589
590 /*
591 * 256MB segment
592 * The proto-VSID space has 2^(CONTEX_BITS + ESID_BITS) - 1 segments
593 * available for user + kernel mapping. VSID 0 is reserved as invalid, contexts
594 * 1-4 are used for kernel mapping. Each segment contains 2^28 bytes. Each
595 * context maps 2^49 bytes (512TB).
596 *
597 * We also need to avoid the last segment of the last context, because that
598 * would give a protovsid of 0x1fffffffff. That will result in a VSID 0
599 * because of the modulo operation in vsid scramble.
600 *
601 */
602 #define MAX_USER_CONTEXT ((ASM_CONST(1) << CONTEXT_BITS) - 2)
603
604 // The + 2 accounts for INVALID_REGION and 1 more to avoid overlap with kernel
605 #define MIN_USER_CONTEXT (MAX_KERNEL_CTX_CNT + MAX_VMALLOC_CTX_CNT + \
606 MAX_IO_CTX_CNT + MAX_VMEMMAP_CTX_CNT + 2)
607
608 /*
609 * For platforms that support on 65bit VA we limit the context bits
610 */
611 #define MAX_USER_CONTEXT_65BIT_VA ((ASM_CONST(1) << (65 - (SID_SHIFT + ESID_BITS))) - 2)
612
613 /*
614 * This should be computed such that protovosid * vsid_mulitplier
615 * doesn't overflow 64 bits. The vsid_mutliplier should also be
616 * co-prime to vsid_modulus. We also need to make sure that number
617 * of bits in multiplied result (dividend) is less than twice the number of
618 * protovsid bits for our modulus optmization to work.
619 *
620 * The below table shows the current values used.
621 * |-------+------------+----------------------+------------+-------------------|
622 * | | Prime Bits | proto VSID_BITS_65VA | Total Bits | 2* prot VSID_BITS |
623 * |-------+------------+----------------------+------------+-------------------|
624 * | 1T | 24 | 25 | 49 | 50 |
625 * |-------+------------+----------------------+------------+-------------------|
626 * | 256MB | 24 | 37 | 61 | 74 |
627 * |-------+------------+----------------------+------------+-------------------|
628 *
629 * |-------+------------+----------------------+------------+--------------------|
630 * | | Prime Bits | proto VSID_BITS_68VA | Total Bits | 2* proto VSID_BITS |
631 * |-------+------------+----------------------+------------+--------------------|
632 * | 1T | 24 | 28 | 52 | 56 |
633 * |-------+------------+----------------------+------------+--------------------|
634 * | 256MB | 24 | 40 | 64 | 80 |
635 * |-------+------------+----------------------+------------+--------------------|
636 *
637 */
638 #define VSID_MULTIPLIER_256M ASM_CONST(12538073) /* 24-bit prime */
639 #define VSID_BITS_256M (VA_BITS - SID_SHIFT)
640 #define VSID_BITS_65_256M (65 - SID_SHIFT)
641 /*
642 * Modular multiplicative inverse of VSID_MULTIPLIER under modulo VSID_MODULUS
643 */
644 #define VSID_MULINV_256M ASM_CONST(665548017062)
645
646 #define VSID_MULTIPLIER_1T ASM_CONST(12538073) /* 24-bit prime */
647 #define VSID_BITS_1T (VA_BITS - SID_SHIFT_1T)
648 #define VSID_BITS_65_1T (65 - SID_SHIFT_1T)
649 #define VSID_MULINV_1T ASM_CONST(209034062)
650
651 /* 1TB VSID reserved for VRMA */
652 #define VRMA_VSID 0x1ffffffUL
653 #define USER_VSID_RANGE (1UL << (ESID_BITS + SID_SHIFT))
654
655 /* 4 bits per slice and we have one slice per 1TB */
656 #define SLICE_ARRAY_SIZE (H_PGTABLE_RANGE >> 41)
657 #define LOW_SLICE_ARRAY_SZ (BITS_PER_LONG / BITS_PER_BYTE)
658 #define TASK_SLICE_ARRAY_SZ(x) ((x)->hash_context->slb_addr_limit >> 41)
659 #ifndef __ASSEMBLY__
660
661 #ifdef CONFIG_PPC_SUBPAGE_PROT
662 /*
663 * For the sub-page protection option, we extend the PGD with one of
664 * these. Basically we have a 3-level tree, with the top level being
665 * the protptrs array. To optimize speed and memory consumption when
666 * only addresses < 4GB are being protected, pointers to the first
667 * four pages of sub-page protection words are stored in the low_prot
668 * array.
669 * Each page of sub-page protection words protects 1GB (4 bytes
670 * protects 64k). For the 3-level tree, each page of pointers then
671 * protects 8TB.
672 */
673 struct subpage_prot_table {
674 unsigned long maxaddr; /* only addresses < this are protected */
675 unsigned int **protptrs[(TASK_SIZE_USER64 >> 43)];
676 unsigned int *low_prot[4];
677 };
678
679 #define SBP_L1_BITS (PAGE_SHIFT - 2)
680 #define SBP_L2_BITS (PAGE_SHIFT - 3)
681 #define SBP_L1_COUNT (1 << SBP_L1_BITS)
682 #define SBP_L2_COUNT (1 << SBP_L2_BITS)
683 #define SBP_L2_SHIFT (PAGE_SHIFT + SBP_L1_BITS)
684 #define SBP_L3_SHIFT (SBP_L2_SHIFT + SBP_L2_BITS)
685
686 extern void subpage_prot_free(struct mm_struct *mm);
687 #else
subpage_prot_free(struct mm_struct * mm)688 static inline void subpage_prot_free(struct mm_struct *mm) {}
689 #endif /* CONFIG_PPC_SUBPAGE_PROT */
690
691 /*
692 * One bit per slice. We have lower slices which cover 256MB segments
693 * upto 4G range. That gets us 16 low slices. For the rest we track slices
694 * in 1TB size.
695 */
696 struct slice_mask {
697 u64 low_slices;
698 DECLARE_BITMAP(high_slices, SLICE_NUM_HIGH);
699 };
700
701 struct hash_mm_context {
702 u16 user_psize; /* page size index */
703
704 /* SLB page size encodings*/
705 unsigned char low_slices_psize[LOW_SLICE_ARRAY_SZ];
706 unsigned char high_slices_psize[SLICE_ARRAY_SIZE];
707 unsigned long slb_addr_limit;
708 #ifdef CONFIG_PPC_64K_PAGES
709 struct slice_mask mask_64k;
710 #endif
711 struct slice_mask mask_4k;
712 #ifdef CONFIG_HUGETLB_PAGE
713 struct slice_mask mask_16m;
714 struct slice_mask mask_16g;
715 #endif
716
717 #ifdef CONFIG_PPC_SUBPAGE_PROT
718 struct subpage_prot_table *spt;
719 #endif /* CONFIG_PPC_SUBPAGE_PROT */
720 };
721
722 #if 0
723 /*
724 * The code below is equivalent to this function for arguments
725 * < 2^VSID_BITS, which is all this should ever be called
726 * with. However gcc is not clever enough to compute the
727 * modulus (2^n-1) without a second multiply.
728 */
729 #define vsid_scramble(protovsid, size) \
730 ((((protovsid) * VSID_MULTIPLIER_##size) % VSID_MODULUS_##size))
731
732 /* simplified form avoiding mod operation */
733 #define vsid_scramble(protovsid, size) \
734 ({ \
735 unsigned long x; \
736 x = (protovsid) * VSID_MULTIPLIER_##size; \
737 x = (x >> VSID_BITS_##size) + (x & VSID_MODULUS_##size); \
738 (x + ((x+1) >> VSID_BITS_##size)) & VSID_MODULUS_##size; \
739 })
740
741 #else /* 1 */
vsid_scramble(unsigned long protovsid,unsigned long vsid_multiplier,int vsid_bits)742 static inline unsigned long vsid_scramble(unsigned long protovsid,
743 unsigned long vsid_multiplier, int vsid_bits)
744 {
745 unsigned long vsid;
746 unsigned long vsid_modulus = ((1UL << vsid_bits) - 1);
747 /*
748 * We have same multipler for both 256 and 1T segements now
749 */
750 vsid = protovsid * vsid_multiplier;
751 vsid = (vsid >> vsid_bits) + (vsid & vsid_modulus);
752 return (vsid + ((vsid + 1) >> vsid_bits)) & vsid_modulus;
753 }
754
755 #endif /* 1 */
756
757 /* Returns the segment size indicator for a user address */
user_segment_size(unsigned long addr)758 static inline int user_segment_size(unsigned long addr)
759 {
760 /* Use 1T segments if possible for addresses >= 1T */
761 if (addr >= (1UL << SID_SHIFT_1T))
762 return mmu_highuser_ssize;
763 return MMU_SEGSIZE_256M;
764 }
765
get_vsid(unsigned long context,unsigned long ea,int ssize)766 static inline unsigned long get_vsid(unsigned long context, unsigned long ea,
767 int ssize)
768 {
769 unsigned long va_bits = VA_BITS;
770 unsigned long vsid_bits;
771 unsigned long protovsid;
772
773 /*
774 * Bad address. We return VSID 0 for that
775 */
776 if ((ea & EA_MASK) >= H_PGTABLE_RANGE)
777 return 0;
778
779 if (!mmu_has_feature(MMU_FTR_68_BIT_VA))
780 va_bits = 65;
781
782 if (ssize == MMU_SEGSIZE_256M) {
783 vsid_bits = va_bits - SID_SHIFT;
784 protovsid = (context << ESID_BITS) |
785 ((ea >> SID_SHIFT) & ESID_BITS_MASK);
786 return vsid_scramble(protovsid, VSID_MULTIPLIER_256M, vsid_bits);
787 }
788 /* 1T segment */
789 vsid_bits = va_bits - SID_SHIFT_1T;
790 protovsid = (context << ESID_BITS_1T) |
791 ((ea >> SID_SHIFT_1T) & ESID_BITS_1T_MASK);
792 return vsid_scramble(protovsid, VSID_MULTIPLIER_1T, vsid_bits);
793 }
794
795 /*
796 * For kernel space, we use context ids as
797 * below. Range is 512TB per context.
798 *
799 * 0x00001 - [ 0xc000000000000000 - 0xc001ffffffffffff]
800 * 0x00002 - [ 0xc002000000000000 - 0xc003ffffffffffff]
801 * 0x00003 - [ 0xc004000000000000 - 0xc005ffffffffffff]
802 * 0x00004 - [ 0xc006000000000000 - 0xc007ffffffffffff]
803 *
804 * vmap, IO, vmemap
805 *
806 * 0x00005 - [ 0xc008000000000000 - 0xc009ffffffffffff]
807 * 0x00006 - [ 0xc00a000000000000 - 0xc00bffffffffffff]
808 * 0x00007 - [ 0xc00c000000000000 - 0xc00dffffffffffff]
809 *
810 */
get_kernel_context(unsigned long ea)811 static inline unsigned long get_kernel_context(unsigned long ea)
812 {
813 unsigned long region_id = get_region_id(ea);
814 unsigned long ctx;
815 /*
816 * Depending on Kernel config, kernel region can have one context
817 * or more.
818 */
819 if (region_id == LINEAR_MAP_REGION_ID) {
820 /*
821 * We already verified ea to be not beyond the addr limit.
822 */
823 ctx = 1 + ((ea & EA_MASK) >> MAX_EA_BITS_PER_CONTEXT);
824 } else
825 ctx = region_id + MAX_KERNEL_CTX_CNT - 1;
826 return ctx;
827 }
828
829 /*
830 * This is only valid for addresses >= PAGE_OFFSET
831 */
get_kernel_vsid(unsigned long ea,int ssize)832 static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
833 {
834 unsigned long context;
835
836 if (!is_kernel_addr(ea))
837 return 0;
838
839 context = get_kernel_context(ea);
840 return get_vsid(context, ea, ssize);
841 }
842
843 unsigned htab_shift_for_mem_size(unsigned long mem_size);
844
845 #endif /* __ASSEMBLY__ */
846
847 #endif /* _ASM_POWERPC_BOOK3S_64_MMU_HASH_H_ */
848