arch/mips/mm/page.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2003, 04, 05 Ralf Baechle (ralf@linux-mips.org)
   7  * Copyright (C) 2007  Maciej W. Rozycki
   8  * Copyright (C) 2008  Thiemo Seufer
   9  * Copyright (C) 2012  MIPS Technologies, Inc.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/smp.h>
  14 #include <linux/mm.h>
  15 #include <linux/proc_fs.h>
  16
  17 #include <asm/bugs.h>
  18 #include <asm/cacheops.h>
  19 #include <asm/cpu-type.h>
  20 #include <asm/inst.h>
  21 #include <asm/io.h>
  22 #include <asm/page.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/prefetch.h>
  25 #include <asm/bootinfo.h>
  26 #include <asm/mipsregs.h>
  27 #include <asm/mmu_context.h>
  28 #include <asm/cpu.h>
  29 #include <asm/war.h>
  30
  31 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
  32 #include <asm/sibyte/sb1250.h>
  33 #include <asm/sibyte/sb1250_regs.h>
  34 #include <asm/sibyte/sb1250_dma.h>
  35 #endif
  36
  37 #include <asm/uasm.h>
  38
  39 /* Registers used in the assembled routines. */
  40 #define ZERO 0
  41 #define AT 2
  42 #define A0 4
  43 #define A1 5
  44 #define A2 6
  45 #define T0 8
  46 #define T1 9
  47 #define T2 10
  48 #define T3 11
  49 #define T9 25
  50 #define RA 31
  51
  52 /* Handle labels (which must be positive integers). */
  53 enum label_id {
  54         label_clear_nopref = 1,
  55         label_clear_pref,
  56         label_copy_nopref,
  57         label_copy_pref_both,
  58         label_copy_pref_store,
  59 };
  60
  61 UASM_L_LA(_clear_nopref)
  62 UASM_L_LA(_clear_pref)
  63 UASM_L_LA(_copy_nopref)
  64 UASM_L_LA(_copy_pref_both)
  65 UASM_L_LA(_copy_pref_store)
  66
  67 /* We need one branch and therefore one relocation per target label. */
  68 static struct uasm_label labels[5];
  69 static struct uasm_reloc relocs[5];
  70
  71 #define cpu_is_r4600_v1_x()     ((read_c0_prid() & 0xfffffff0) == 0x00002010)
  72 #define cpu_is_r4600_v2_x()     ((read_c0_prid() & 0xfffffff0) == 0x00002020)
  73
  74 /*
  75  * R6 has a limited offset of the pref instruction.
  76  * Skip it if the offset is more than 9 bits.
  77  */
  78 #define _uasm_i_pref(a, b, c, d)                \
  79 do {                                            \
  80         if (cpu_has_mips_r6) {                  \
  81                 if (c <= 0xff && c >= -0x100)   \
  82                         uasm_i_pref(a, b, c, d);\
  83         } else {                                \
  84                 uasm_i_pref(a, b, c, d);        \
  85         }                                       \
  86 } while(0)
  87
  88 static int pref_bias_clear_store;
  89 static int pref_bias_copy_load;
  90 static int pref_bias_copy_store;
  91
  92 static u32 pref_src_mode;
  93 static u32 pref_dst_mode;
  94
  95 static int clear_word_size;
  96 static int copy_word_size;
  97
  98 static int half_clear_loop_size;
  99 static int half_copy_loop_size;
 100
 101 static int cache_line_size;
 102 #define cache_line_mask() (cache_line_size - 1)
 103
 104 static inline void
 105 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
 106 {
 107         if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
 108                 if (off > 0x7fff) {
 109                         uasm_i_lui(buf, T9, uasm_rel_hi(off));
 110                         uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
 111                 } else
 112                         uasm_i_addiu(buf, T9, ZERO, off);
 113                 uasm_i_daddu(buf, reg1, reg2, T9);
 114         } else {
 115                 if (off > 0x7fff) {
 116                         uasm_i_lui(buf, T9, uasm_rel_hi(off));
 117                         uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
 118                         UASM_i_ADDU(buf, reg1, reg2, T9);
 119                 } else
 120                         UASM_i_ADDIU(buf, reg1, reg2, off);
 121         }
 122 }
 123
 124 static void set_prefetch_parameters(void)
 125 {
 126         if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
 127                 clear_word_size = 8;
 128         else
 129                 clear_word_size = 4;
 130
 131         if (cpu_has_64bit_gp_regs)
 132                 copy_word_size = 8;
 133         else
 134                 copy_word_size = 4;
 135
 136         /*
 137          * The pref's used here are using "streaming" hints, which cause the
 138          * copied data to be kicked out of the cache sooner.  A page copy often
 139          * ends up copying a lot more data than is commonly used, so this seems
 140          * to make sense in terms of reducing cache pollution, but I've no real
 141          * performance data to back this up.
 142          */
 143         if (cpu_has_prefetch) {
 144                 /*
 145                  * XXX: Most prefetch bias values in here are based on
 146                  * guesswork.
 147                  */
 148                 cache_line_size = cpu_dcache_line_size();
 149                 switch (current_cpu_type()) {
 150                 case CPU_R5500:
 151                 case CPU_TX49XX:
 152                         /* These processors only support the Pref_Load. */
 153                         pref_bias_copy_load = 256;
 154                         break;
 155
 156                 case CPU_R10000:
 157                 case CPU_R12000:
 158                 case CPU_R14000:
 159                 case CPU_R16000:
 160                         /*
 161                          * Those values have been experimentally tuned for an
 162                          * Origin 200.
 163                          */
 164                         pref_bias_clear_store = 512;
 165                         pref_bias_copy_load = 256;
 166                         pref_bias_copy_store = 256;
 167                         pref_src_mode = Pref_LoadStreamed;
 168                         pref_dst_mode = Pref_StoreStreamed;
 169                         break;
 170
 171                 case CPU_SB1:
 172                 case CPU_SB1A:
 173                         pref_bias_clear_store = 128;
 174                         pref_bias_copy_load = 128;
 175                         pref_bias_copy_store = 128;
 176                         /*
 177                          * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
 178                          * hints are broken.
 179                          */
 180                         if (current_cpu_type() == CPU_SB1 &&
 181                             (current_cpu_data.processor_id & 0xff) < 0x02) {
 182                                 pref_src_mode = Pref_Load;
 183                                 pref_dst_mode = Pref_Store;
 184                         } else {
 185                                 pref_src_mode = Pref_LoadStreamed;
 186                                 pref_dst_mode = Pref_StoreStreamed;
 187                         }
 188                         break;
 189
 190                 case CPU_LOONGSON3:
 191                         /* Loongson-3 only support the Pref_Load/Pref_Store. */
 192                         pref_bias_clear_store = 128;
 193                         pref_bias_copy_load = 128;
 194                         pref_bias_copy_store = 128;
 195                         pref_src_mode = Pref_Load;
 196                         pref_dst_mode = Pref_Store;
 197                         break;
 198
 199                 default:
 200                         pref_bias_clear_store = 128;
 201                         pref_bias_copy_load = 256;
 202                         pref_bias_copy_store = 128;
 203                         pref_src_mode = Pref_LoadStreamed;
 204                         if (cpu_has_mips_r6)
 205                                 /*
 206                                  * Bit 30 (Pref_PrepareForStore) has been
 207                                  * removed from MIPS R6. Use bit 5
 208                                  * (Pref_StoreStreamed).
 209                                  */
 210                                 pref_dst_mode = Pref_StoreStreamed;
 211                         else
 212                                 pref_dst_mode = Pref_PrepareForStore;
 213                         break;
 214                 }
 215         } else {
 216                 if (cpu_has_cache_cdex_s)
 217                         cache_line_size = cpu_scache_line_size();
 218                 else if (cpu_has_cache_cdex_p)
 219                         cache_line_size = cpu_dcache_line_size();
 220         }
 221         /*
 222          * Too much unrolling will overflow the available space in
 223          * clear_space_array / copy_page_array.
 224          */
 225         half_clear_loop_size = min(16 * clear_word_size,
 226                                    max(cache_line_size >> 1,
 227                                        4 * clear_word_size));
 228         half_copy_loop_size = min(16 * copy_word_size,
 229                                   max(cache_line_size >> 1,
 230                                       4 * copy_word_size));
 231 }
 232
 233 static void build_clear_store(u32 **buf, int off)
 234 {
 235         if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
 236                 uasm_i_sd(buf, ZERO, off, A0);
 237         } else {
 238                 uasm_i_sw(buf, ZERO, off, A0);
 239         }
 240 }
 241
 242 static inline void build_clear_pref(u32 **buf, int off)
 243 {
 244         if (off & cache_line_mask())
 245                 return;
 246
 247         if (pref_bias_clear_store) {
 248                 _uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
 249                             A0);
 250         } else if (cache_line_size == (half_clear_loop_size << 1)) {
 251                 if (cpu_has_cache_cdex_s) {
 252                         uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 253                 } else if (cpu_has_cache_cdex_p) {
 254                         if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 255                                 uasm_i_nop(buf);
 256                                 uasm_i_nop(buf);
 257                                 uasm_i_nop(buf);
 258                                 uasm_i_nop(buf);
 259                         }
 260
 261                         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 262                                 uasm_i_lw(buf, ZERO, ZERO, AT);
 263
 264                         uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 265                 }
 266         }
 267 }
 268
 269 extern u32 __clear_page_start;
 270 extern u32 __clear_page_end;
 271 extern u32 __copy_page_start;
 272 extern u32 __copy_page_end;
 273
 274 void build_clear_page(void)
 275 {
 276         int off;
 277         u32 *buf = &__clear_page_start;
 278         struct uasm_label *l = labels;
 279         struct uasm_reloc *r = relocs;
 280         int i;
 281         static atomic_t run_once = ATOMIC_INIT(0);
 282
 283         if (atomic_xchg(&run_once, 1)) {
 284                 return;
 285         }
 286
 287         memset(labels, 0, sizeof(labels));
 288         memset(relocs, 0, sizeof(relocs));
 289
 290         set_prefetch_parameters();
 291
 292         /*
 293          * This algorithm makes the following assumptions:
 294          *   - The prefetch bias is a multiple of 2 words.
 295          *   - The prefetch bias is less than one page.
 296          */
 297         BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
 298         BUG_ON(PAGE_SIZE < pref_bias_clear_store);
 299
 300         off = PAGE_SIZE - pref_bias_clear_store;
 301         if (off > 0xffff || !pref_bias_clear_store)
 302                 pg_addiu(&buf, A2, A0, off);
 303         else
 304                 uasm_i_ori(&buf, A2, A0, off);
 305
 306         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 307                 uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
 308
 309         off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
 310                                 * cache_line_size : 0;
 311         while (off) {
 312                 build_clear_pref(&buf, -off);
 313                 off -= cache_line_size;
 314         }
 315         uasm_l_clear_pref(&l, buf);
 316         do {
 317                 build_clear_pref(&buf, off);
 318                 build_clear_store(&buf, off);
 319                 off += clear_word_size;
 320         } while (off < half_clear_loop_size);
 321         pg_addiu(&buf, A0, A0, 2 * off);
 322         off = -off;
 323         do {
 324                 build_clear_pref(&buf, off);
 325                 if (off == -clear_word_size)
 326                         uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
 327                 build_clear_store(&buf, off);
 328                 off += clear_word_size;
 329         } while (off < 0);
 330
 331         if (pref_bias_clear_store) {
 332                 pg_addiu(&buf, A2, A0, pref_bias_clear_store);
 333                 uasm_l_clear_nopref(&l, buf);
 334                 off = 0;
 335                 do {
 336                         build_clear_store(&buf, off);
 337                         off += clear_word_size;
 338                 } while (off < half_clear_loop_size);
 339                 pg_addiu(&buf, A0, A0, 2 * off);
 340                 off = -off;
 341                 do {
 342                         if (off == -clear_word_size)
 343                                 uasm_il_bne(&buf, &r, A0, A2,
 344                                             label_clear_nopref);
 345                         build_clear_store(&buf, off);
 346                         off += clear_word_size;
 347                 } while (off < 0);
 348         }
 349
 350         uasm_i_jr(&buf, RA);
 351         uasm_i_nop(&buf);
 352
 353         BUG_ON(buf > &__clear_page_end);
 354
 355         uasm_resolve_relocs(relocs, labels);
 356
 357         pr_debug("Synthesized clear page handler (%u instructions).\n",
 358                  (u32)(buf - &__clear_page_start));
 359
 360         pr_debug("\t.set push\n");
 361         pr_debug("\t.set noreorder\n");
 362         for (i = 0; i < (buf - &__clear_page_start); i++)
 363                 pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
 364         pr_debug("\t.set pop\n");
 365 }
 366
 367 static void build_copy_load(u32 **buf, int reg, int off)
 368 {
 369         if (cpu_has_64bit_gp_regs) {
 370                 uasm_i_ld(buf, reg, off, A1);
 371         } else {
 372                 uasm_i_lw(buf, reg, off, A1);
 373         }
 374 }
 375
 376 static void build_copy_store(u32 **buf, int reg, int off)
 377 {
 378         if (cpu_has_64bit_gp_regs) {
 379                 uasm_i_sd(buf, reg, off, A0);
 380         } else {
 381                 uasm_i_sw(buf, reg, off, A0);
 382         }
 383 }
 384
 385 static inline void build_copy_load_pref(u32 **buf, int off)
 386 {
 387         if (off & cache_line_mask())
 388                 return;
 389
 390         if (pref_bias_copy_load)
 391                 _uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
 392 }
 393
 394 static inline void build_copy_store_pref(u32 **buf, int off)
 395 {
 396         if (off & cache_line_mask())
 397                 return;
 398
 399         if (pref_bias_copy_store) {
 400                 _uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
 401                             A0);
 402         } else if (cache_line_size == (half_copy_loop_size << 1)) {
 403                 if (cpu_has_cache_cdex_s) {
 404                         uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 405                 } else if (cpu_has_cache_cdex_p) {
 406                         if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 407                                 uasm_i_nop(buf);
 408                                 uasm_i_nop(buf);
 409                                 uasm_i_nop(buf);
 410                                 uasm_i_nop(buf);
 411                         }
 412
 413                         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 414                                 uasm_i_lw(buf, ZERO, ZERO, AT);
 415
 416                         uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 417                 }
 418         }
 419 }
 420
 421 void build_copy_page(void)
 422 {
 423         int off;
 424         u32 *buf = &__copy_page_start;
 425         struct uasm_label *l = labels;
 426         struct uasm_reloc *r = relocs;
 427         int i;
 428         static atomic_t run_once = ATOMIC_INIT(0);
 429
 430         if (atomic_xchg(&run_once, 1)) {
 431                 return;
 432         }
 433
 434         memset(labels, 0, sizeof(labels));
 435         memset(relocs, 0, sizeof(relocs));
 436
 437         set_prefetch_parameters();
 438
 439         /*
 440          * This algorithm makes the following assumptions:
 441          *   - All prefetch biases are multiples of 8 words.
 442          *   - The prefetch biases are less than one page.
 443          *   - The store prefetch bias isn't greater than the load
 444          *     prefetch bias.
 445          */
 446         BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
 447         BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
 448         BUG_ON(PAGE_SIZE < pref_bias_copy_load);
 449         BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
 450
 451         off = PAGE_SIZE - pref_bias_copy_load;
 452         if (off > 0xffff || !pref_bias_copy_load)
 453                 pg_addiu(&buf, A2, A0, off);
 454         else
 455                 uasm_i_ori(&buf, A2, A0, off);
 456
 457         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 458                 uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
 459
 460         off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
 461                                 cache_line_size : 0;
 462         while (off) {
 463                 build_copy_load_pref(&buf, -off);
 464                 off -= cache_line_size;
 465         }
 466         off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
 467                                 cache_line_size : 0;
 468         while (off) {
 469                 build_copy_store_pref(&buf, -off);
 470                 off -= cache_line_size;
 471         }
 472         uasm_l_copy_pref_both(&l, buf);
 473         do {
 474                 build_copy_load_pref(&buf, off);
 475                 build_copy_load(&buf, T0, off);
 476                 build_copy_load_pref(&buf, off + copy_word_size);
 477                 build_copy_load(&buf, T1, off + copy_word_size);
 478                 build_copy_load_pref(&buf, off + 2 * copy_word_size);
 479                 build_copy_load(&buf, T2, off + 2 * copy_word_size);
 480                 build_copy_load_pref(&buf, off + 3 * copy_word_size);
 481                 build_copy_load(&buf, T3, off + 3 * copy_word_size);
 482                 build_copy_store_pref(&buf, off);
 483                 build_copy_store(&buf, T0, off);
 484                 build_copy_store_pref(&buf, off + copy_word_size);
 485                 build_copy_store(&buf, T1, off + copy_word_size);
 486                 build_copy_store_pref(&buf, off + 2 * copy_word_size);
 487                 build_copy_store(&buf, T2, off + 2 * copy_word_size);
 488                 build_copy_store_pref(&buf, off + 3 * copy_word_size);
 489                 build_copy_store(&buf, T3, off + 3 * copy_word_size);
 490                 off += 4 * copy_word_size;
 491         } while (off < half_copy_loop_size);
 492         pg_addiu(&buf, A1, A1, 2 * off);
 493         pg_addiu(&buf, A0, A0, 2 * off);
 494         off = -off;
 495         do {
 496                 build_copy_load_pref(&buf, off);
 497                 build_copy_load(&buf, T0, off);
 498                 build_copy_load_pref(&buf, off + copy_word_size);
 499                 build_copy_load(&buf, T1, off + copy_word_size);
 500                 build_copy_load_pref(&buf, off + 2 * copy_word_size);
 501                 build_copy_load(&buf, T2, off + 2 * copy_word_size);
 502                 build_copy_load_pref(&buf, off + 3 * copy_word_size);
 503                 build_copy_load(&buf, T3, off + 3 * copy_word_size);
 504                 build_copy_store_pref(&buf, off);
 505                 build_copy_store(&buf, T0, off);
 506                 build_copy_store_pref(&buf, off + copy_word_size);
 507                 build_copy_store(&buf, T1, off + copy_word_size);
 508                 build_copy_store_pref(&buf, off + 2 * copy_word_size);
 509                 build_copy_store(&buf, T2, off + 2 * copy_word_size);
 510                 build_copy_store_pref(&buf, off + 3 * copy_word_size);
 511                 if (off == -(4 * copy_word_size))
 512                         uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
 513                 build_copy_store(&buf, T3, off + 3 * copy_word_size);
 514                 off += 4 * copy_word_size;
 515         } while (off < 0);
 516
 517         if (pref_bias_copy_load - pref_bias_copy_store) {
 518                 pg_addiu(&buf, A2, A0,
 519                          pref_bias_copy_load - pref_bias_copy_store);
 520                 uasm_l_copy_pref_store(&l, buf);
 521                 off = 0;
 522                 do {
 523                         build_copy_load(&buf, T0, off);
 524                         build_copy_load(&buf, T1, off + copy_word_size);
 525                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 526                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 527                         build_copy_store_pref(&buf, off);
 528                         build_copy_store(&buf, T0, off);
 529                         build_copy_store_pref(&buf, off + copy_word_size);
 530                         build_copy_store(&buf, T1, off + copy_word_size);
 531                         build_copy_store_pref(&buf, off + 2 * copy_word_size);
 532                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 533                         build_copy_store_pref(&buf, off + 3 * copy_word_size);
 534                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 535                         off += 4 * copy_word_size;
 536                 } while (off < half_copy_loop_size);
 537                 pg_addiu(&buf, A1, A1, 2 * off);
 538                 pg_addiu(&buf, A0, A0, 2 * off);
 539                 off = -off;
 540                 do {
 541                         build_copy_load(&buf, T0, off);
 542                         build_copy_load(&buf, T1, off + copy_word_size);
 543                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 544                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 545                         build_copy_store_pref(&buf, off);
 546                         build_copy_store(&buf, T0, off);
 547                         build_copy_store_pref(&buf, off + copy_word_size);
 548                         build_copy_store(&buf, T1, off + copy_word_size);
 549                         build_copy_store_pref(&buf, off + 2 * copy_word_size);
 550                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 551                         build_copy_store_pref(&buf, off + 3 * copy_word_size);
 552                         if (off == -(4 * copy_word_size))
 553                                 uasm_il_bne(&buf, &r, A2, A0,
 554                                             label_copy_pref_store);
 555                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 556                         off += 4 * copy_word_size;
 557                 } while (off < 0);
 558         }
 559
 560         if (pref_bias_copy_store) {
 561                 pg_addiu(&buf, A2, A0, pref_bias_copy_store);
 562                 uasm_l_copy_nopref(&l, buf);
 563                 off = 0;
 564                 do {
 565                         build_copy_load(&buf, T0, off);
 566                         build_copy_load(&buf, T1, off + copy_word_size);
 567                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 568                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 569                         build_copy_store(&buf, T0, off);
 570                         build_copy_store(&buf, T1, off + copy_word_size);
 571                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 572                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 573                         off += 4 * copy_word_size;
 574                 } while (off < half_copy_loop_size);
 575                 pg_addiu(&buf, A1, A1, 2 * off);
 576                 pg_addiu(&buf, A0, A0, 2 * off);
 577                 off = -off;
 578                 do {
 579                         build_copy_load(&buf, T0, off);
 580                         build_copy_load(&buf, T1, off + copy_word_size);
 581                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 582                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 583                         build_copy_store(&buf, T0, off);
 584                         build_copy_store(&buf, T1, off + copy_word_size);
 585                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 586                         if (off == -(4 * copy_word_size))
 587                                 uasm_il_bne(&buf, &r, A2, A0,
 588                                             label_copy_nopref);
 589                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 590                         off += 4 * copy_word_size;
 591                 } while (off < 0);
 592         }
 593
 594         uasm_i_jr(&buf, RA);
 595         uasm_i_nop(&buf);
 596
 597         BUG_ON(buf > &__copy_page_end);
 598
 599         uasm_resolve_relocs(relocs, labels);
 600
 601         pr_debug("Synthesized copy page handler (%u instructions).\n",
 602                  (u32)(buf - &__copy_page_start));
 603
 604         pr_debug("\t.set push\n");
 605         pr_debug("\t.set noreorder\n");
 606         for (i = 0; i < (buf - &__copy_page_start); i++)
 607                 pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
 608         pr_debug("\t.set pop\n");
 609 }
 610
 611 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
 612 extern void clear_page_cpu(void *page);
 613 extern void copy_page_cpu(void *to, void *from);
 614
 615 /*
 616  * Pad descriptors to cacheline, since each is exclusively owned by a
 617  * particular CPU.
 618  */
 619 struct dmadscr {
 620         u64 dscr_a;
 621         u64 dscr_b;
 622         u64 pad_a;
 623         u64 pad_b;
 624 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
 625
 626 void clear_page(void *page)
 627 {
 628         u64 to_phys = CPHYSADDR((unsigned long)page);
 629         unsigned int cpu = smp_processor_id();
 630
 631         /* if the page is not in KSEG0, use old way */
 632         if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
 633                 return clear_page_cpu(page);
 634
 635         page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
 636                                  M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
 637         page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 638         __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 639
 640         /*
 641          * Don't really want to do it this way, but there's no
 642          * reliable way to delay completion detection.
 643          */
 644         while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 645                  & M_DM_DSCR_BASE_INTERRUPT))
 646                 ;
 647         __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 648 }
 649 EXPORT_SYMBOL(clear_page);
 650
 651 void copy_page(void *to, void *from)
 652 {
 653         u64 from_phys = CPHYSADDR((unsigned long)from);
 654         u64 to_phys = CPHYSADDR((unsigned long)to);
 655         unsigned int cpu = smp_processor_id();
 656
 657         /* if any page is not in KSEG0, use old way */
 658         if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
 659             || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
 660                 return copy_page_cpu(to, from);
 661
 662         page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
 663                                  M_DM_DSCRA_INTERRUPT;
 664         page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 665         __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 666
 667         /*
 668          * Don't really want to do it this way, but there's no
 669          * reliable way to delay completion detection.
 670          */
 671         while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 672                  & M_DM_DSCR_BASE_INTERRUPT))
 673                 ;
 674         __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 675 }
 676 EXPORT_SYMBOL(copy_page);
 677
 678 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */