arch/powerpc/include/asm/book3s/64/mmu-hash.h

   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_BIT0         ASM_CONST(0x2000000000000000)
  90 #define HPTE_R_KEY_BIT1         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_BIT3         ASM_CONST(0x0000000000000400)
 107 #define HPTE_R_KEY_BIT4         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
 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
 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
 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
 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
 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
 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
 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
 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
 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  */
 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  */
 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
 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
 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
 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
 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  */
 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  */
 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  */
 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  */
 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
 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
 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 (MAX_PHYSMEM_BITS > MAX_EA_BITS_PER_CONTEXT)
 581 #define MAX_KERNEL_CTX_CNT      (1UL << (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
 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 */
 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 */
 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
 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 below
 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  */
 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  */
 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_ */