include/asm-powerpc/mmu-hash64.h

   1 #ifndef _ASM_POWERPC_MMU_HASH64_H_
   2 #define _ASM_POWERPC_MMU_HASH64_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/asm-compat.h>
  16 #include <asm/page.h>
  17
  18 /*
  19  * Segment table
  20  */
  21
  22 #define STE_ESID_V      0x80
  23 #define STE_ESID_KS     0x20
  24 #define STE_ESID_KP     0x10
  25 #define STE_ESID_N      0x08
  26
  27 #define STE_VSID_SHIFT  12
  28
  29 /* Location of cpu0's segment table */
  30 #define STAB0_PAGE      0x6
  31 #define STAB0_OFFSET    (STAB0_PAGE << 12)
  32 #define STAB0_PHYS_ADDR (STAB0_OFFSET + PHYSICAL_START)
  33
  34 #ifndef __ASSEMBLY__
  35 extern char initial_stab[];
  36 #endif /* ! __ASSEMBLY */
  37
  38 /*
  39  * SLB
  40  */
  41
  42 #define SLB_NUM_BOLTED          3
  43 #define SLB_CACHE_ENTRIES       8
  44
  45 /* Bits in the SLB ESID word */
  46 #define SLB_ESID_V              ASM_CONST(0x0000000008000000) /* valid */
  47
  48 /* Bits in the SLB VSID word */
  49 #define SLB_VSID_SHIFT          12
  50 #define SLB_VSID_SHIFT_1T       24
  51 #define SLB_VSID_SSIZE_SHIFT    62
  52 #define SLB_VSID_B              ASM_CONST(0xc000000000000000)
  53 #define SLB_VSID_B_256M         ASM_CONST(0x0000000000000000)
  54 #define SLB_VSID_B_1T           ASM_CONST(0x4000000000000000)
  55 #define SLB_VSID_KS             ASM_CONST(0x0000000000000800)
  56 #define SLB_VSID_KP             ASM_CONST(0x0000000000000400)
  57 #define SLB_VSID_N              ASM_CONST(0x0000000000000200) /* no-execute */
  58 #define SLB_VSID_L              ASM_CONST(0x0000000000000100)
  59 #define SLB_VSID_C              ASM_CONST(0x0000000000000080) /* class */
  60 #define SLB_VSID_LP             ASM_CONST(0x0000000000000030)
  61 #define SLB_VSID_LP_00          ASM_CONST(0x0000000000000000)
  62 #define SLB_VSID_LP_01          ASM_CONST(0x0000000000000010)
  63 #define SLB_VSID_LP_10          ASM_CONST(0x0000000000000020)
  64 #define SLB_VSID_LP_11          ASM_CONST(0x0000000000000030)
  65 #define SLB_VSID_LLP            (SLB_VSID_L|SLB_VSID_LP)
  66
  67 #define SLB_VSID_KERNEL         (SLB_VSID_KP)
  68 #define SLB_VSID_USER           (SLB_VSID_KP|SLB_VSID_KS|SLB_VSID_C)
  69
  70 #define SLBIE_C                 (0x08000000)
  71 #define SLBIE_SSIZE_SHIFT       25
  72
  73 /*
  74  * Hash table
  75  */
  76
  77 #define HPTES_PER_GROUP 8
  78
  79 #define HPTE_V_SSIZE_SHIFT      62
  80 #define HPTE_V_AVPN_SHIFT       7
  81 #define HPTE_V_AVPN             ASM_CONST(0x3fffffffffffff80)
  82 #define HPTE_V_AVPN_VAL(x)      (((x) & HPTE_V_AVPN) >> HPTE_V_AVPN_SHIFT)
  83 #define HPTE_V_COMPARE(x,y)     (!(((x) ^ (y)) & 0xffffffffffffff80UL))
  84 #define HPTE_V_BOLTED           ASM_CONST(0x0000000000000010)
  85 #define HPTE_V_LOCK             ASM_CONST(0x0000000000000008)
  86 #define HPTE_V_LARGE            ASM_CONST(0x0000000000000004)
  87 #define HPTE_V_SECONDARY        ASM_CONST(0x0000000000000002)
  88 #define HPTE_V_VALID            ASM_CONST(0x0000000000000001)
  89
  90 #define HPTE_R_PP0              ASM_CONST(0x8000000000000000)
  91 #define HPTE_R_TS               ASM_CONST(0x4000000000000000)
  92 #define HPTE_R_RPN_SHIFT        12
  93 #define HPTE_R_RPN              ASM_CONST(0x3ffffffffffff000)
  94 #define HPTE_R_FLAGS            ASM_CONST(0x00000000000003ff)
  95 #define HPTE_R_PP               ASM_CONST(0x0000000000000003)
  96 #define HPTE_R_N                ASM_CONST(0x0000000000000004)
  97 #define HPTE_R_C                ASM_CONST(0x0000000000000080)
  98 #define HPTE_R_R                ASM_CONST(0x0000000000000100)
  99
 100 #define HPTE_V_1TB_SEG          ASM_CONST(0x4000000000000000)
 101 #define HPTE_V_VRMA_MASK        ASM_CONST(0x4001ffffff000000)
 102
 103 /* Values for PP (assumes Ks=0, Kp=1) */
 104 /* pp0 will always be 0 for linux     */
 105 #define PP_RWXX 0       /* Supervisor read/write, User none */
 106 #define PP_RWRX 1       /* Supervisor read/write, User read */
 107 #define PP_RWRW 2       /* Supervisor read/write, User read/write */
 108 #define PP_RXRX 3       /* Supervisor read,       User read */
 109
 110 #ifndef __ASSEMBLY__
 111
 112 struct hash_pte {
 113         unsigned long v;
 114         unsigned long r;
 115 };
 116
 117 extern struct hash_pte *htab_address;
 118 extern unsigned long htab_size_bytes;
 119 extern unsigned long htab_hash_mask;
 120
 121 /*
 122  * Page size definition
 123  *
 124  *    shift : is the "PAGE_SHIFT" value for that page size
 125  *    sllp  : is a bit mask with the value of SLB L || LP to be or'ed
 126  *            directly to a slbmte "vsid" value
 127  *    penc  : is the HPTE encoding mask for the "LP" field:
 128  *
 129  */
 130 struct mmu_psize_def
 131 {
 132         unsigned int    shift;  /* number of bits */
 133         unsigned int    penc;   /* HPTE encoding */
 134         unsigned int    tlbiel; /* tlbiel supported for that page size */
 135         unsigned long   avpnm;  /* bits to mask out in AVPN in the HPTE */
 136         unsigned long   sllp;   /* SLB L||LP (exact mask to use in slbmte) */
 137 };
 138
 139 #endif /* __ASSEMBLY__ */
 140
 141 /*
 142  * The kernel use the constants below to index in the page sizes array.
 143  * The use of fixed constants for this purpose is better for performances
 144  * of the low level hash refill handlers.
 145  *
 146  * A non supported page size has a "shift" field set to 0
 147  *
 148  * Any new page size being implemented can get a new entry in here. Whether
 149  * the kernel will use it or not is a different matter though. The actual page
 150  * size used by hugetlbfs is not defined here and may be made variable
 151  */
 152
 153 #define MMU_PAGE_4K             0       /* 4K */
 154 #define MMU_PAGE_64K            1       /* 64K */
 155 #define MMU_PAGE_64K_AP         2       /* 64K Admixed (in a 4K segment) */
 156 #define MMU_PAGE_1M             3       /* 1M */
 157 #define MMU_PAGE_16M            4       /* 16M */
 158 #define MMU_PAGE_16G            5       /* 16G */
 159 #define MMU_PAGE_COUNT          6
 160
 161 /*
 162  * Segment sizes.
 163  * These are the values used by hardware in the B field of
 164  * SLB entries and the first dword of MMU hashtable entries.
 165  * The B field is 2 bits; the values 2 and 3 are unused and reserved.
 166  */
 167 #define MMU_SEGSIZE_256M        0
 168 #define MMU_SEGSIZE_1T          1
 169
 170
 171 #ifndef __ASSEMBLY__
 172
 173 /*
 174  * The current system page and segment sizes
 175  */
 176 extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
 177 extern int mmu_linear_psize;
 178 extern int mmu_virtual_psize;
 179 extern int mmu_vmalloc_psize;
 180 extern int mmu_vmemmap_psize;
 181 extern int mmu_io_psize;
 182 extern int mmu_kernel_ssize;
 183 extern int mmu_highuser_ssize;
 184 extern u16 mmu_slb_size;
 185 extern unsigned long tce_alloc_start, tce_alloc_end;
 186
 187 /*
 188  * If the processor supports 64k normal pages but not 64k cache
 189  * inhibited pages, we have to be prepared to switch processes
 190  * to use 4k pages when they create cache-inhibited mappings.
 191  * If this is the case, mmu_ci_restrictions will be set to 1.
 192  */
 193 extern int mmu_ci_restrictions;
 194
 195 #ifdef CONFIG_HUGETLB_PAGE
 196 /*
 197  * The page size indexes of the huge pages for use by hugetlbfs
 198  */
 199 extern unsigned int mmu_huge_psizes[MMU_PAGE_COUNT];
 200
 201 #endif /* CONFIG_HUGETLB_PAGE */
 202
 203 /*
 204  * This function sets the AVPN and L fields of the HPTE  appropriately
 205  * for the page size
 206  */
 207 static inline unsigned long hpte_encode_v(unsigned long va, int psize,
 208                                           int ssize)
 209 {
 210         unsigned long v;
 211         v = (va >> 23) & ~(mmu_psize_defs[psize].avpnm);
 212         v <<= HPTE_V_AVPN_SHIFT;
 213         if (psize != MMU_PAGE_4K)
 214                 v |= HPTE_V_LARGE;
 215         v |= ((unsigned long) ssize) << HPTE_V_SSIZE_SHIFT;
 216         return v;
 217 }
 218
 219 /*
 220  * This function sets the ARPN, and LP fields of the HPTE appropriately
 221  * for the page size. We assume the pa is already "clean" that is properly
 222  * aligned for the requested page size
 223  */
 224 static inline unsigned long hpte_encode_r(unsigned long pa, int psize)
 225 {
 226         unsigned long r;
 227
 228         /* A 4K page needs no special encoding */
 229         if (psize == MMU_PAGE_4K)
 230                 return pa & HPTE_R_RPN;
 231         else {
 232                 unsigned int penc = mmu_psize_defs[psize].penc;
 233                 unsigned int shift = mmu_psize_defs[psize].shift;
 234                 return (pa & ~((1ul << shift) - 1)) | (penc << 12);
 235         }
 236         return r;
 237 }
 238
 239 /*
 240  * Build a VA given VSID, EA and segment size
 241  */
 242 static inline unsigned long hpt_va(unsigned long ea, unsigned long vsid,
 243                                    int ssize)
 244 {
 245         if (ssize == MMU_SEGSIZE_256M)
 246                 return (vsid << 28) | (ea & 0xfffffffUL);
 247         return (vsid << 40) | (ea & 0xffffffffffUL);
 248 }
 249
 250 /*
 251  * This hashes a virtual address
 252  */
 253
 254 static inline unsigned long hpt_hash(unsigned long va, unsigned int shift,
 255                                      int ssize)
 256 {
 257         unsigned long hash, vsid;
 258
 259         if (ssize == MMU_SEGSIZE_256M) {
 260                 hash = (va >> 28) ^ ((va & 0x0fffffffUL) >> shift);
 261         } else {
 262                 vsid = va >> 40;
 263                 hash = vsid ^ (vsid << 25) ^ ((va & 0xffffffffffUL) >> shift);
 264         }
 265         return hash & 0x7fffffffffUL;
 266 }
 267
 268 extern int __hash_page_4K(unsigned long ea, unsigned long access,
 269                           unsigned long vsid, pte_t *ptep, unsigned long trap,
 270                           unsigned int local, int ssize, int subpage_prot);
 271 extern int __hash_page_64K(unsigned long ea, unsigned long access,
 272                            unsigned long vsid, pte_t *ptep, unsigned long trap,
 273                            unsigned int local, int ssize);
 274 struct mm_struct;
 275 extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap);
 276 extern int hash_huge_page(struct mm_struct *mm, unsigned long access,
 277                           unsigned long ea, unsigned long vsid, int local,
 278                           unsigned long trap);
 279
 280 extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
 281                              unsigned long pstart, unsigned long mode,
 282                              int psize, int ssize);
 283 extern void set_huge_psize(int psize);
 284 extern void add_gpage(unsigned long addr, unsigned long page_size,
 285                           unsigned long number_of_pages);
 286 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
 287
 288 extern void htab_initialize(void);
 289 extern void htab_initialize_secondary(void);
 290 extern void hpte_init_native(void);
 291 extern void hpte_init_lpar(void);
 292 extern void hpte_init_iSeries(void);
 293 extern void hpte_init_beat(void);
 294 extern void hpte_init_beat_v3(void);
 295
 296 extern void stabs_alloc(void);
 297 extern void slb_initialize(void);
 298 extern void slb_flush_and_rebolt(void);
 299 extern void stab_initialize(unsigned long stab);
 300
 301 extern void slb_vmalloc_update(void);
 302 #endif /* __ASSEMBLY__ */
 303
 304 /*
 305  * VSID allocation
 306  *
 307  * We first generate a 36-bit "proto-VSID".  For kernel addresses this
 308  * is equal to the ESID, for user addresses it is:
 309  *      (context << 15) | (esid & 0x7fff)
 310  *
 311  * The two forms are distinguishable because the top bit is 0 for user
 312  * addresses, whereas the top two bits are 1 for kernel addresses.
 313  * Proto-VSIDs with the top two bits equal to 0b10 are reserved for
 314  * now.
 315  *
 316  * The proto-VSIDs are then scrambled into real VSIDs with the
 317  * multiplicative hash:
 318  *
 319  *      VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
 320  *      where   VSID_MULTIPLIER = 268435399 = 0xFFFFFC7
 321  *              VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF
 322  *
 323  * This scramble is only well defined for proto-VSIDs below
 324  * 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are
 325  * reserved.  VSID_MULTIPLIER is prime, so in particular it is
 326  * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
 327  * Because the modulus is 2^n-1 we can compute it efficiently without
 328  * a divide or extra multiply (see below).
 329  *
 330  * This scheme has several advantages over older methods:
 331  *
 332  *      - We have VSIDs allocated for every kernel address
 333  * (i.e. everything above 0xC000000000000000), except the very top
 334  * segment, which simplifies several things.
 335  *
 336  *      - We allow for 15 significant bits of ESID and 20 bits of
 337  * context for user addresses.  i.e. 8T (43 bits) of address space for
 338  * up to 1M contexts (although the page table structure and context
 339  * allocation will need changes to take advantage of this).
 340  *
 341  *      - The scramble function gives robust scattering in the hash
 342  * table (at least based on some initial results).  The previous
 343  * method was more susceptible to pathological cases giving excessive
 344  * hash collisions.
 345  */
 346 /*
 347  * WARNING - If you change these you must make sure the asm
 348  * implementations in slb_allocate (slb_low.S), do_stab_bolted
 349  * (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly.
 350  *
 351  * You'll also need to change the precomputed VSID values in head.S
 352  * which are used by the iSeries firmware.
 353  */
 354
 355 #define VSID_MULTIPLIER_256M    ASM_CONST(200730139)    /* 28-bit prime */
 356 #define VSID_BITS_256M          36
 357 #define VSID_MODULUS_256M       ((1UL<<VSID_BITS_256M)-1)
 358
 359 #define VSID_MULTIPLIER_1T      ASM_CONST(12538073)     /* 24-bit prime */
 360 #define VSID_BITS_1T            24
 361 #define VSID_MODULUS_1T         ((1UL<<VSID_BITS_1T)-1)
 362
 363 #define CONTEXT_BITS            19
 364 #define USER_ESID_BITS          16
 365 #define USER_ESID_BITS_1T       4
 366
 367 #define USER_VSID_RANGE (1UL << (USER_ESID_BITS + SID_SHIFT))
 368
 369 /*
 370  * This macro generates asm code to compute the VSID scramble
 371  * function.  Used in slb_allocate() and do_stab_bolted.  The function
 372  * computed is: (protovsid*VSID_MULTIPLIER) % VSID_MODULUS
 373  *
 374  *      rt = register continaing the proto-VSID and into which the
 375  *              VSID will be stored
 376  *      rx = scratch register (clobbered)
 377  *
 378  *      - rt and rx must be different registers
 379  *      - The answer will end up in the low VSID_BITS bits of rt.  The higher
 380  *        bits may contain other garbage, so you may need to mask the
 381  *        result.
 382  */
 383 #define ASM_VSID_SCRAMBLE(rt, rx, size)                                 \
 384         lis     rx,VSID_MULTIPLIER_##size@h;                            \
 385         ori     rx,rx,VSID_MULTIPLIER_##size@l;                         \
 386         mulld   rt,rt,rx;               /* rt = rt * MULTIPLIER */      \
 387                                                                         \
 388         srdi    rx,rt,VSID_BITS_##size;                                 \
 389         clrldi  rt,rt,(64-VSID_BITS_##size);                            \
 390         add     rt,rt,rx;               /* add high and low bits */     \
 391         /* Now, r3 == VSID (mod 2^36-1), and lies between 0 and         \
 392          * 2^36-1+2^28-1.  That in particular means that if r3 >=       \
 393          * 2^36-1, then r3+1 has the 2^36 bit set.  So, if r3+1 has     \
 394          * the bit clear, r3 already has the answer we want, if it      \
 395          * doesn't, the answer is the low 36 bits of r3+1.  So in all   \
 396          * cases the answer is the low 36 bits of (r3 + ((r3+1) >> 36))*/\
 397         addi    rx,rt,1;                                                \
 398         srdi    rx,rx,VSID_BITS_##size; /* extract 2^VSID_BITS bit */   \
 399         add     rt,rt,rx
 400
 401
 402 #ifndef __ASSEMBLY__
 403
 404 typedef unsigned long mm_context_id_t;
 405
 406 typedef struct {
 407         mm_context_id_t id;
 408         u16 user_psize;         /* page size index */
 409
 410 #ifdef CONFIG_PPC_MM_SLICES
 411         u64 low_slices_psize;   /* SLB page size encodings */
 412         u64 high_slices_psize;  /* 4 bits per slice for now */
 413 #else
 414         u16 sllp;               /* SLB page size encoding */
 415 #endif
 416         unsigned long vdso_base;
 417 } mm_context_t;
 418
 419
 420 #if 0
 421 /*
 422  * The code below is equivalent to this function for arguments
 423  * < 2^VSID_BITS, which is all this should ever be called
 424  * with.  However gcc is not clever enough to compute the
 425  * modulus (2^n-1) without a second multiply.
 426  */
 427 #define vsid_scrample(protovsid, size) \
 428         ((((protovsid) * VSID_MULTIPLIER_##size) % VSID_MODULUS_##size))
 429
 430 #else /* 1 */
 431 #define vsid_scramble(protovsid, size) \
 432         ({                                                               \
 433                 unsigned long x;                                         \
 434                 x = (protovsid) * VSID_MULTIPLIER_##size;                \
 435                 x = (x >> VSID_BITS_##size) + (x & VSID_MODULUS_##size); \
 436                 (x + ((x+1) >> VSID_BITS_##size)) & VSID_MODULUS_##size; \
 437         })
 438 #endif /* 1 */
 439
 440 /* This is only valid for addresses >= KERNELBASE */
 441 static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
 442 {
 443         if (ssize == MMU_SEGSIZE_256M)
 444                 return vsid_scramble(ea >> SID_SHIFT, 256M);
 445         return vsid_scramble(ea >> SID_SHIFT_1T, 1T);
 446 }
 447
 448 /* Returns the segment size indicator for a user address */
 449 static inline int user_segment_size(unsigned long addr)
 450 {
 451         /* Use 1T segments if possible for addresses >= 1T */
 452         if (addr >= (1UL << SID_SHIFT_1T))
 453                 return mmu_highuser_ssize;
 454         return MMU_SEGSIZE_256M;
 455 }
 456
 457 /* This is only valid for user addresses (which are below 2^44) */
 458 static inline unsigned long get_vsid(unsigned long context, unsigned long ea,
 459                                      int ssize)
 460 {
 461         if (ssize == MMU_SEGSIZE_256M)
 462                 return vsid_scramble((context << USER_ESID_BITS)
 463                                      | (ea >> SID_SHIFT), 256M);
 464         return vsid_scramble((context << USER_ESID_BITS_1T)
 465                              | (ea >> SID_SHIFT_1T), 1T);
 466 }
 467
 468 /*
 469  * This is only used on legacy iSeries in lparmap.c,
 470  * hence the 256MB segment assumption.
 471  */
 472 #define VSID_SCRAMBLE(pvsid)    (((pvsid) * VSID_MULTIPLIER_256M) %     \
 473                                  VSID_MODULUS_256M)
 474 #define KERNEL_VSID(ea)         VSID_SCRAMBLE(GET_ESID(ea))
 475
 476 #endif /* __ASSEMBLY__ */
 477
 478 #endif /* _ASM_POWERPC_MMU_HASH64_H_ */