linux/arch/powerpc/include/asm/mmu-hash64.h
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   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__
  35extern 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
 112struct hash_pte {
 113        unsigned long v;
 114        unsigned long r;
 115};
 116
 117extern struct hash_pte *htab_address;
 118extern unsigned long htab_size_bytes;
 119extern 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 */
 130struct 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 */
 176extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
 177extern int mmu_linear_psize;
 178extern int mmu_virtual_psize;
 179extern int mmu_vmalloc_psize;
 180extern int mmu_vmemmap_psize;
 181extern int mmu_io_psize;
 182extern int mmu_kernel_ssize;
 183extern int mmu_highuser_ssize;
 184extern u16 mmu_slb_size;
 185extern 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 */
 193extern 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 */
 199extern 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 */
 207static 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 */
 224static 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 */
 242static 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
 254static 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
 268extern 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);
 271extern 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);
 274struct mm_struct;
 275extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap);
 276extern 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
 280extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
 281                             unsigned long pstart, unsigned long prot,
 282                             int psize, int ssize);
 283extern void add_gpage(unsigned long addr, unsigned long page_size,
 284                          unsigned long number_of_pages);
 285extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
 286
 287extern void hpte_init_native(void);
 288extern void hpte_init_lpar(void);
 289extern void hpte_init_iSeries(void);
 290extern void hpte_init_beat(void);
 291extern void hpte_init_beat_v3(void);
 292
 293extern void stabs_alloc(void);
 294extern void slb_initialize(void);
 295extern void slb_flush_and_rebolt(void);
 296extern void stab_initialize(unsigned long stab);
 297
 298extern void slb_vmalloc_update(void);
 299#endif /* __ASSEMBLY__ */
 300
 301/*
 302 * VSID allocation
 303 *
 304 * We first generate a 36-bit "proto-VSID".  For kernel addresses this
 305 * is equal to the ESID, for user addresses it is:
 306 *      (context << 15) | (esid & 0x7fff)
 307 *
 308 * The two forms are distinguishable because the top bit is 0 for user
 309 * addresses, whereas the top two bits are 1 for kernel addresses.
 310 * Proto-VSIDs with the top two bits equal to 0b10 are reserved for
 311 * now.
 312 *
 313 * The proto-VSIDs are then scrambled into real VSIDs with the
 314 * multiplicative hash:
 315 *
 316 *      VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
 317 *      where   VSID_MULTIPLIER = 268435399 = 0xFFFFFC7
 318 *              VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF
 319 *
 320 * This scramble is only well defined for proto-VSIDs below
 321 * 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are
 322 * reserved.  VSID_MULTIPLIER is prime, so in particular it is
 323 * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
 324 * Because the modulus is 2^n-1 we can compute it efficiently without
 325 * a divide or extra multiply (see below).
 326 *
 327 * This scheme has several advantages over older methods:
 328 *
 329 *      - We have VSIDs allocated for every kernel address
 330 * (i.e. everything above 0xC000000000000000), except the very top
 331 * segment, which simplifies several things.
 332 *
 333 *      - We allow for 15 significant bits of ESID and 20 bits of
 334 * context for user addresses.  i.e. 8T (43 bits) of address space for
 335 * up to 1M contexts (although the page table structure and context
 336 * allocation will need changes to take advantage of this).
 337 *
 338 *      - The scramble function gives robust scattering in the hash
 339 * table (at least based on some initial results).  The previous
 340 * method was more susceptible to pathological cases giving excessive
 341 * hash collisions.
 342 */
 343/*
 344 * WARNING - If you change these you must make sure the asm
 345 * implementations in slb_allocate (slb_low.S), do_stab_bolted
 346 * (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly.
 347 *
 348 * You'll also need to change the precomputed VSID values in head.S
 349 * which are used by the iSeries firmware.
 350 */
 351
 352#define VSID_MULTIPLIER_256M    ASM_CONST(200730139)    /* 28-bit prime */
 353#define VSID_BITS_256M          36
 354#define VSID_MODULUS_256M       ((1UL<<VSID_BITS_256M)-1)
 355
 356#define VSID_MULTIPLIER_1T      ASM_CONST(12538073)     /* 24-bit prime */
 357#define VSID_BITS_1T            24
 358#define VSID_MODULUS_1T         ((1UL<<VSID_BITS_1T)-1)
 359
 360#define CONTEXT_BITS            19
 361#define USER_ESID_BITS          16
 362#define USER_ESID_BITS_1T       4
 363
 364#define USER_VSID_RANGE (1UL << (USER_ESID_BITS + SID_SHIFT))
 365
 366/*
 367 * This macro generates asm code to compute the VSID scramble
 368 * function.  Used in slb_allocate() and do_stab_bolted.  The function
 369 * computed is: (protovsid*VSID_MULTIPLIER) % VSID_MODULUS
 370 *
 371 *      rt = register continaing the proto-VSID and into which the
 372 *              VSID will be stored
 373 *      rx = scratch register (clobbered)
 374 *
 375 *      - rt and rx must be different registers
 376 *      - The answer will end up in the low VSID_BITS bits of rt.  The higher
 377 *        bits may contain other garbage, so you may need to mask the
 378 *        result.
 379 */
 380#define ASM_VSID_SCRAMBLE(rt, rx, size)                                 \
 381        lis     rx,VSID_MULTIPLIER_##size@h;                            \
 382        ori     rx,rx,VSID_MULTIPLIER_##size@l;                         \
 383        mulld   rt,rt,rx;               /* rt = rt * MULTIPLIER */      \
 384                                                                        \
 385        srdi    rx,rt,VSID_BITS_##size;                                 \
 386        clrldi  rt,rt,(64-VSID_BITS_##size);                            \
 387        add     rt,rt,rx;               /* add high and low bits */     \
 388        /* Now, r3 == VSID (mod 2^36-1), and lies between 0 and         \
 389         * 2^36-1+2^28-1.  That in particular means that if r3 >=       \
 390         * 2^36-1, then r3+1 has the 2^36 bit set.  So, if r3+1 has     \
 391         * the bit clear, r3 already has the answer we want, if it      \
 392         * doesn't, the answer is the low 36 bits of r3+1.  So in all   \
 393         * cases the answer is the low 36 bits of (r3 + ((r3+1) >> 36))*/\
 394        addi    rx,rt,1;                                                \
 395        srdi    rx,rx,VSID_BITS_##size; /* extract 2^VSID_BITS bit */   \
 396        add     rt,rt,rx
 397
 398
 399#ifndef __ASSEMBLY__
 400
 401typedef unsigned long mm_context_id_t;
 402
 403typedef struct {
 404        mm_context_id_t id;
 405        u16 user_psize;         /* page size index */
 406
 407#ifdef CONFIG_PPC_MM_SLICES
 408        u64 low_slices_psize;   /* SLB page size encodings */
 409        u64 high_slices_psize;  /* 4 bits per slice for now */
 410#else
 411        u16 sllp;               /* SLB page size encoding */
 412#endif
 413        unsigned long vdso_base;
 414} mm_context_t;
 415
 416
 417#if 0
 418/*
 419 * The code below is equivalent to this function for arguments
 420 * < 2^VSID_BITS, which is all this should ever be called
 421 * with.  However gcc is not clever enough to compute the
 422 * modulus (2^n-1) without a second multiply.
 423 */
 424#define vsid_scrample(protovsid, size) \
 425        ((((protovsid) * VSID_MULTIPLIER_##size) % VSID_MODULUS_##size))
 426
 427#else /* 1 */
 428#define vsid_scramble(protovsid, size) \
 429        ({                                                               \
 430                unsigned long x;                                         \
 431                x = (protovsid) * VSID_MULTIPLIER_##size;                \
 432                x = (x >> VSID_BITS_##size) + (x & VSID_MODULUS_##size); \
 433                (x + ((x+1) >> VSID_BITS_##size)) & VSID_MODULUS_##size; \
 434        })
 435#endif /* 1 */
 436
 437/* This is only valid for addresses >= PAGE_OFFSET */
 438static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize)
 439{
 440        if (ssize == MMU_SEGSIZE_256M)
 441                return vsid_scramble(ea >> SID_SHIFT, 256M);
 442        return vsid_scramble(ea >> SID_SHIFT_1T, 1T);
 443}
 444
 445/* Returns the segment size indicator for a user address */
 446static inline int user_segment_size(unsigned long addr)
 447{
 448        /* Use 1T segments if possible for addresses >= 1T */
 449        if (addr >= (1UL << SID_SHIFT_1T))
 450                return mmu_highuser_ssize;
 451        return MMU_SEGSIZE_256M;
 452}
 453
 454/* This is only valid for user addresses (which are below 2^44) */
 455static inline unsigned long get_vsid(unsigned long context, unsigned long ea,
 456                                     int ssize)
 457{
 458        if (ssize == MMU_SEGSIZE_256M)
 459                return vsid_scramble((context << USER_ESID_BITS)
 460                                     | (ea >> SID_SHIFT), 256M);
 461        return vsid_scramble((context << USER_ESID_BITS_1T)
 462                             | (ea >> SID_SHIFT_1T), 1T);
 463}
 464
 465/*
 466 * This is only used on legacy iSeries in lparmap.c,
 467 * hence the 256MB segment assumption.
 468 */
 469#define VSID_SCRAMBLE(pvsid)    (((pvsid) * VSID_MULTIPLIER_256M) %     \
 470                                 VSID_MODULUS_256M)
 471#define KERNEL_VSID(ea)         VSID_SCRAMBLE(GET_ESID(ea))
 472
 473#endif /* __ASSEMBLY__ */
 474
 475#endif /* _ASM_POWERPC_MMU_HASH64_H_ */
 476