release/src-rt-6.x/linux/linux-2.6/include/asm-sparc64/tsb.h

   1 #ifndef _SPARC64_TSB_H
   2 #define _SPARC64_TSB_H
   3
   4 /* The sparc64 TSB is similar to the powerpc hashtables.  It's a
   5  * power-of-2 sized table of TAG/PTE pairs.  The cpu precomputes
   6  * pointers into this table for 8K and 64K page sizes, and also a
   7  * comparison TAG based upon the virtual address and context which
   8  * faults.
   9  *
  10  * TLB miss trap handler software does the actual lookup via something
  11  * of the form:
  12  *
  13  *      ldxa            [%g0] ASI_{D,I}MMU_TSB_8KB_PTR, %g1
  14  *      ldxa            [%g0] ASI_{D,I}MMU, %g6
  15  *      sllx            %g6, 22, %g6
  16  *      srlx            %g6, 22, %g6
  17  *      ldda            [%g1] ASI_NUCLEUS_QUAD_LDD, %g4
  18  *      cmp             %g4, %g6
  19  *      bne,pn  %xcc, tsb_miss_{d,i}tlb
  20  *       mov            FAULT_CODE_{D,I}TLB, %g3
  21  *      stxa            %g5, [%g0] ASI_{D,I}TLB_DATA_IN
  22  *      retry
  23  *
  24  *
  25  * Each 16-byte slot of the TSB is the 8-byte tag and then the 8-byte
  26  * PTE.  The TAG is of the same layout as the TLB TAG TARGET mmu
  27  * register which is:
  28  *
  29  * -------------------------------------------------
  30  * |  -  |  CONTEXT |  -  |    VADDR bits 63:22    |
  31  * -------------------------------------------------
  32  *  63 61 60      48 47 42 41                     0
  33  *
  34  * But actually, since we use per-mm TSB's, we zero out the CONTEXT
  35  * field.
  36  *
  37  * Like the powerpc hashtables we need to use locking in order to
  38  * synchronize while we update the entries.  PTE updates need locking
  39  * as well.
  40  *
  41  * We need to carefully choose a lock bits for the TSB entry.  We
  42  * choose to use bit 47 in the tag.  Also, since we never map anything
  43  * at page zero in context zero, we use zero as an invalid tag entry.
  44  * When the lock bit is set, this forces a tag comparison failure.
  45  */
  46
  47 #define TSB_TAG_LOCK_BIT        47
  48 #define TSB_TAG_LOCK_HIGH       (1 << (TSB_TAG_LOCK_BIT - 32))
  49
  50 #define TSB_TAG_INVALID_BIT     46
  51 #define TSB_TAG_INVALID_HIGH    (1 << (TSB_TAG_INVALID_BIT - 32))
  52
  53 #define TSB_MEMBAR      membar  #StoreStore
  54
  55 /* Some cpus support physical address quad loads.  We want to use
  56  * those if possible so we don't need to hard-lock the TSB mapping
  57  * into the TLB.  We encode some instruction patching in order to
  58  * support this.
  59  *
  60  * The kernel TSB is locked into the TLB by virtue of being in the
  61  * kernel image, so we don't play these games for swapper_tsb access.
  62  */
  63 #ifndef __ASSEMBLY__
  64 struct tsb_ldquad_phys_patch_entry {
  65         unsigned int    addr;
  66         unsigned int    sun4u_insn;
  67         unsigned int    sun4v_insn;
  68 };
  69 extern struct tsb_ldquad_phys_patch_entry __tsb_ldquad_phys_patch,
  70         __tsb_ldquad_phys_patch_end;
  71
  72 struct tsb_phys_patch_entry {
  73         unsigned int    addr;
  74         unsigned int    insn;
  75 };
  76 extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
  77 #endif
  78 #define TSB_LOAD_QUAD(TSB, REG) \
  79 661:    ldda            [TSB] ASI_NUCLEUS_QUAD_LDD, REG; \
  80         .section        .tsb_ldquad_phys_patch, "ax"; \
  81         .word           661b; \
  82         ldda            [TSB] ASI_QUAD_LDD_PHYS, REG; \
  83         ldda            [TSB] ASI_QUAD_LDD_PHYS_4V, REG; \
  84         .previous
  85
  86 #define TSB_LOAD_TAG_HIGH(TSB, REG) \
  87 661:    lduwa           [TSB] ASI_N, REG; \
  88         .section        .tsb_phys_patch, "ax"; \
  89         .word           661b; \
  90         lduwa           [TSB] ASI_PHYS_USE_EC, REG; \
  91         .previous
  92
  93 #define TSB_LOAD_TAG(TSB, REG) \
  94 661:    ldxa            [TSB] ASI_N, REG; \
  95         .section        .tsb_phys_patch, "ax"; \
  96         .word           661b; \
  97         ldxa            [TSB] ASI_PHYS_USE_EC, REG; \
  98         .previous
  99
 100 #define TSB_CAS_TAG_HIGH(TSB, REG1, REG2) \
 101 661:    casa            [TSB] ASI_N, REG1, REG2; \
 102         .section        .tsb_phys_patch, "ax"; \
 103         .word           661b; \
 104         casa            [TSB] ASI_PHYS_USE_EC, REG1, REG2; \
 105         .previous
 106
 107 #define TSB_CAS_TAG(TSB, REG1, REG2) \
 108 661:    casxa           [TSB] ASI_N, REG1, REG2; \
 109         .section        .tsb_phys_patch, "ax"; \
 110         .word           661b; \
 111         casxa           [TSB] ASI_PHYS_USE_EC, REG1, REG2; \
 112         .previous
 113
 114 #define TSB_STORE(ADDR, VAL) \
 115 661:    stxa            VAL, [ADDR] ASI_N; \
 116         .section        .tsb_phys_patch, "ax"; \
 117         .word           661b; \
 118         stxa            VAL, [ADDR] ASI_PHYS_USE_EC; \
 119         .previous
 120
 121 #define TSB_LOCK_TAG(TSB, REG1, REG2)   \
 122 99:     TSB_LOAD_TAG_HIGH(TSB, REG1);   \
 123         sethi   %hi(TSB_TAG_LOCK_HIGH), REG2;\
 124         andcc   REG1, REG2, %g0;        \
 125         bne,pn  %icc, 99b;              \
 126          nop;                           \
 127         TSB_CAS_TAG_HIGH(TSB, REG1, REG2);      \
 128         cmp     REG1, REG2;             \
 129         bne,pn  %icc, 99b;              \
 130          nop;                           \
 131         TSB_MEMBAR
 132
 133 #define TSB_WRITE(TSB, TTE, TAG) \
 134         add     TSB, 0x8, TSB;   \
 135         TSB_STORE(TSB, TTE);     \
 136         sub     TSB, 0x8, TSB;   \
 137         TSB_MEMBAR;              \
 138         TSB_STORE(TSB, TAG);
 139
 140 #define KTSB_LOAD_QUAD(TSB, REG) \
 141         ldda            [TSB] ASI_NUCLEUS_QUAD_LDD, REG;
 142
 143 #define KTSB_STORE(ADDR, VAL) \
 144         stxa            VAL, [ADDR] ASI_N;
 145
 146 #define KTSB_LOCK_TAG(TSB, REG1, REG2)  \
 147 99:     lduwa   [TSB] ASI_N, REG1;      \
 148         sethi   %hi(TSB_TAG_LOCK_HIGH), REG2;\
 149         andcc   REG1, REG2, %g0;        \
 150         bne,pn  %icc, 99b;              \
 151          nop;                           \
 152         casa    [TSB] ASI_N, REG1, REG2;\
 153         cmp     REG1, REG2;             \
 154         bne,pn  %icc, 99b;              \
 155          nop;                           \
 156         TSB_MEMBAR
 157
 158 #define KTSB_WRITE(TSB, TTE, TAG) \
 159         add     TSB, 0x8, TSB;   \
 160         stxa    TTE, [TSB] ASI_N;     \
 161         sub     TSB, 0x8, TSB;   \
 162         TSB_MEMBAR;              \
 163         stxa    TAG, [TSB] ASI_N;
 164
 165         /* Do a kernel page table walk.  Leaves physical PTE pointer in
 166          * REG1.  Jumps to FAIL_LABEL on early page table walk termination.
 167          * VADDR will not be clobbered, but REG2 will.
 168          */
 169 #define KERN_PGTABLE_WALK(VADDR, REG1, REG2, FAIL_LABEL)        \
 170         sethi           %hi(swapper_pg_dir), REG1; \
 171         or              REG1, %lo(swapper_pg_dir), REG1; \
 172         sllx            VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
 173         srlx            REG2, 64 - PAGE_SHIFT, REG2; \
 174         andn            REG2, 0x3, REG2; \
 175         lduw            [REG1 + REG2], REG1; \
 176         brz,pn          REG1, FAIL_LABEL; \
 177          sllx           VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
 178         srlx            REG2, 64 - PAGE_SHIFT, REG2; \
 179         sllx            REG1, 11, REG1; \
 180         andn            REG2, 0x3, REG2; \
 181         lduwa           [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
 182         brz,pn          REG1, FAIL_LABEL; \
 183          sllx           VADDR, 64 - PMD_SHIFT, REG2; \
 184         srlx            REG2, 64 - PAGE_SHIFT, REG2; \
 185         sllx            REG1, 11, REG1; \
 186         andn            REG2, 0x7, REG2; \
 187         add             REG1, REG2, REG1;
 188
 189         /* Do a user page table walk in MMU globals.  Leaves physical PTE
 190          * pointer in REG1.  Jumps to FAIL_LABEL on early page table walk
 191          * termination.  Physical base of page tables is in PHYS_PGD which
 192          * will not be modified.
 193          *
 194          * VADDR will not be clobbered, but REG1 and REG2 will.
 195          */
 196 #define USER_PGTABLE_WALK_TL1(VADDR, PHYS_PGD, REG1, REG2, FAIL_LABEL)  \
 197         sllx            VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
 198         srlx            REG2, 64 - PAGE_SHIFT, REG2; \
 199         andn            REG2, 0x3, REG2; \
 200         lduwa           [PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \
 201         brz,pn          REG1, FAIL_LABEL; \
 202          sllx           VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
 203         srlx            REG2, 64 - PAGE_SHIFT, REG2; \
 204         sllx            REG1, 11, REG1; \
 205         andn            REG2, 0x3, REG2; \
 206         lduwa           [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
 207         brz,pn          REG1, FAIL_LABEL; \
 208          sllx           VADDR, 64 - PMD_SHIFT, REG2; \
 209         srlx            REG2, 64 - PAGE_SHIFT, REG2; \
 210         sllx            REG1, 11, REG1; \
 211         andn            REG2, 0x7, REG2; \
 212         add             REG1, REG2, REG1;
 213
 214 /* Lookup a OBP mapping on VADDR in the prom_trans[] table at TL>0.
 215  * If no entry is found, FAIL_LABEL will be branched to.  On success
 216  * the resulting PTE value will be left in REG1.  VADDR is preserved
 217  * by this routine.
 218  */
 219 #define OBP_TRANS_LOOKUP(VADDR, REG1, REG2, REG3, FAIL_LABEL) \
 220         sethi           %hi(prom_trans), REG1; \
 221         or              REG1, %lo(prom_trans), REG1; \
 222 97:     ldx             [REG1 + 0x00], REG2; \
 223         brz,pn          REG2, FAIL_LABEL; \
 224          nop; \
 225         ldx             [REG1 + 0x08], REG3; \
 226         add             REG2, REG3, REG3; \
 227         cmp             REG2, VADDR; \
 228         bgu,pt          %xcc, 98f; \
 229          cmp            VADDR, REG3; \
 230         bgeu,pt         %xcc, 98f; \
 231          ldx            [REG1 + 0x10], REG3; \
 232         sub             VADDR, REG2, REG2; \
 233         ba,pt           %xcc, 99f; \
 234          add            REG3, REG2, REG1; \
 235 98:     ba,pt           %xcc, 97b; \
 236          add            REG1, (3 * 8), REG1; \
 237 99:
 238
 239         /* We use a 32K TSB for the whole kernel, this allows to
 240          * handle about 16MB of modules and vmalloc mappings without
 241          * incurring many hash conflicts.
 242          */
 243 #define KERNEL_TSB_SIZE_BYTES   (32 * 1024)
 244 #define KERNEL_TSB_NENTRIES     \
 245         (KERNEL_TSB_SIZE_BYTES / 16)
 246 #define KERNEL_TSB4M_NENTRIES   4096
 247
 248         /* Do a kernel TSB lookup at tl>0 on VADDR+TAG, branch to OK_LABEL
 249          * on TSB hit.  REG1, REG2, REG3, and REG4 are used as temporaries
 250          * and the found TTE will be left in REG1.  REG3 and REG4 must
 251          * be an even/odd pair of registers.
 252          *
 253          * VADDR and TAG will be preserved and not clobbered by this macro.
 254          */
 255 #define KERN_TSB_LOOKUP_TL1(VADDR, TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
 256         sethi           %hi(swapper_tsb), REG1; \
 257         or              REG1, %lo(swapper_tsb), REG1; \
 258         srlx            VADDR, PAGE_SHIFT, REG2; \
 259         and             REG2, (KERNEL_TSB_NENTRIES - 1), REG2; \
 260         sllx            REG2, 4, REG2; \
 261         add             REG1, REG2, REG2; \
 262         KTSB_LOAD_QUAD(REG2, REG3); \
 263         cmp             REG3, TAG; \
 264         be,a,pt         %xcc, OK_LABEL; \
 265          mov            REG4, REG1;
 266
 267 #ifndef CONFIG_DEBUG_PAGEALLOC
 268         /* This version uses a trick, the TAG is already (VADDR >> 22) so
 269          * we can make use of that for the index computation.
 270          */
 271 #define KERN_TSB4M_LOOKUP_TL1(TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
 272         sethi           %hi(swapper_4m_tsb), REG1; \
 273         or              REG1, %lo(swapper_4m_tsb), REG1; \
 274         and             TAG, (KERNEL_TSB4M_NENTRIES - 1), REG2; \
 275         sllx            REG2, 4, REG2; \
 276         add             REG1, REG2, REG2; \
 277         KTSB_LOAD_QUAD(REG2, REG3); \
 278         cmp             REG3, TAG; \
 279         be,a,pt         %xcc, OK_LABEL; \
 280          mov            REG4, REG1;
 281 #endif
 282
 283 #endif /* !(_SPARC64_TSB_H) */